# 21st International Symposium on Very High Energy Cosmic Ray Interactions - ISVHECRI 2022 (Virtual)

Asia/Calcutta
GRAPES-3 Collaboration (Tata Institute of Fundamental Research), India

#### GRAPES-3 Collaboration (Tata Institute of Fundamental Research), India

Description

The 21st International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2022) will be hosted by the GRAPES-3 Collaboration (Tata Institute of Fundamental Research), India during May 23-27, 2022. Please note that this symposium was originally scheduled to be held during June 4-8, 2020, however, it was postponed due to the pandemic.

ISVHECRI is a biennial conference series supported by the International Union of Pure and Applied Physics (IUPAP). Its primary objective is to provide a forum for the discussion of very high energy interactions for the interpretation of cosmic ray data based on the information available from both accelerator and cosmic ray experiments. This unique series brings together cosmic ray physicists and scientists involved with high energy accelerators and colliding beam facilities.

Symposium topics:

• High energy astroparticle physics results relevant to particle physics
• Accelerator experiments relevant to cosmic ray physics
• Space experiment results relevant to high energy interactions
• Exotic phenomena & searches for new physics beyond SM
• LHC pp & heavy ion physics
• Cross-sections and interaction models
• High energy neutrinos and muons, including muon puzzle
• Simulation tools for cosmic ray & neutrino physics
• Multi-messenger cosmic ray observations & interpretations
• Future accelerators & cosmic ray experiments

The Symposium will consist of invited and contributed talks. All the talks will be organized in plenary sessions. There will be talks from all the major cosmic ray, gamma-ray & neutrino experiments as well as collider experiments (especially on forward physics), and also a special session on the “Cosmic muon puzzle”.

Important dates:

Mar 15       : Opening of registration
Mar 15       : Opening of abstract submission

Apr 14        : Closing of abstract submission
Apr 21        : Extension of abstract submission
May 1         : Announcement of decision on submitted abstracts
May 22       : Last date for payment
May 23-27 : Symposium dates

ISVHECRI series (started 1980):

Supported by

Participants
• Abbas Raham
• Abhinav Choudhury
• Akimichi Taketa
• Albert De Roeck
• Aleksei Bogdanov
• Alexander Borisov
• Alexander Kalweit
• Allan Hallgren
• Anatoli Fedynitch
• Anatoly Petrukhin
• Anna Ivanova
• Annarita Margiotta
• Anton Lukyashin
• Antonella Castellina
• ANUJ CHANDRA
• Arnab Sarker
• Arun Babu Kollamparambil Paul
• ARUNIMA BHATTACHARYA
• Atul Jain
• Babita Kumari
• Bakhtiyar Iskakov
• Bhanu Pant
• Bibhuti Parida
• Bikash Thapa
• Bryan Pattison
• Christian Glaser
• Christophe Royon
• Cunfeng Feng
• D Indumathi
• Damiano Fiorillo
• Daniele Fargion
• David d'Enterria
• Debanjan Bose
• Dennis Soldin
• Diptiranjan Pattanaik
• Donghwa Kang
• Eduardo de la Fuente Acosta
• Elena Pinetti
• Fahim Varsi
• felix riehn
• Gagan Mohanty
• Giulia Pancheri
• Giuseppe Di Sciascio
• Gulmurod Shoziyoev
• Hans Dembinski
• Hariharan Balakrishnan
• Hiroaki Menjo
• Hiroyuki Sagawa
• Honey Khindri
• Hushnud Hushnud
• Igor Petrov
• Indranil Das
• Jakub Vicha
• James Pinfold
• JAYAPRAKASH BEHERA
• Jeau Mishr
• Johannes Eser
• Jones JP
• Jorge Antonio Morales-Soto
• Joshi Yogeshkumar Dileepkumar
• Joy Ganguly
• Juan Carlos Arteaga-Velazquez
• Jörg Hörandel
• Kajal Kajal
• Karam Chand
• Karl-Heinz Kampert
• Keitaro Fujita
• Ken Ohashi
• Konstantinos Tanidis
• Krishna Prabha P A
• L. VENKATESAM REDDY
• Leandro Silveri
• Lokendra Singh
• Lorenzo Cazon
• Luca Orusa
• Luis Anchordoqui
• Mahak Garg
• MAHIMA SACHDEVA
• Mamta Jangra
• Mandar Saraf
• Manisha Lohan
• Manoj Kumar
• Manoj Kumar Singh
• Masato Takita
• Maximilian Reininghaus
• Medha Chakraborty
• Meeran Zuberi
• Moe Kondo
• Moon Moon Devi
• NARESH KUMAR PATRA
• Nijil Mankuzhiyil
• Nikolay Budnev
• Olga Botner
• Olga Piskounova
• Olivier Deligny
• Oscar Romero Matamala
• Pankaj Jain
• Pethuraj Sankaranarayanan
• Pierre Sokolsky
• Pranaba Nayak
• Pratik Majumdar
• Pravata Mohanty
• Qianhang Ding
• Qidong Zhou
• raj shah
• Ralph Engel
• Rameez Mohamed
• Rashmi Dhamija
• Rauf Mukhamedshin
• Razmik Mirzoyan
• Rhorry Gauld
• Rim M. Mirzafatiknov
• Roman Nikolaenko
• Ruben Conceição
• Saburo Kawakami
• Sachin Venkatesh Thakku Saravana Kumar
• Saken Shinbulatov
• Saraswati Pandey
• Satyanarayana Bheesette
• Saurabh Sandilya
• Sergei S. Borisov
• Sergey Ostapchenko
• Sergey Pyatovsky
• Sergey Shaulov
• Shoichi Ogio
• Shoushan Zhang
• Sonal Dhingra
• Sonal Ramesh Patel
• Sonali Bhatnagar
• Sosuke Okukawa
• Stanislav Knurenko
• Stef Verpoest
• Subir Sarkar
• Sunanda .
• Sunil Kumar Gupta
• Surojit Paul
• Suryanarayan Mondal
• Swapna Mahapatra
• Swaraj Pratim Sarmah
• Takaaki Kajita
• Takashi Sako
• Tanguy Pierog
• Teruyoshi Kawashima
• Thomas Paul
• Tianlu Yuan
• Tim Huege
• Timur Dzhatdoev
• Umananda Dev Goswami
• Vasily Prosin
• Vera G Sinitsyna
• Vera Yu. Sinitsyna
• Xiaoting Feng
• Yasushi Muraki
• Yoshinari Hayato
• Yoshitaka Itow
• Yosui Akaike
• Yuya Nakamura
Contact
• Monday, 23 May
• 14:30 15:30
Inauguration
Convener: Indranil Mazumdar (TIFR, Mumbai)
• 15:30 16:30
Invited talks
Convener: Subir Sarkar (University of Oxford)
• 15:30
Constraints from the latest CMS data 30m

Constraints from the latest CMS data ---collected in p-p, p-Pb, and Pb-Pb collisions--- on hadronic event generators for ultra-high energy cosmic-ray physics will be presented.

Speaker: David d'Enterria (CERN)
• 16:00
ALICE at the LHC and astrophysics: from providing input for the search for anti-nuclei in space to constraining the equation-of-state of neutron stars 30m

The ALICE experiment at the LHC was originally designed to study the creation of the quark-gluon-plasma in heavy-ion collisions, a new state of matter in which quarks and gluons are not confined into hadrons. More recently, the versatility of both the Large Hadron Collider and the ALICE apparatus have given additionally access to a unique set of nuclear and hadronic physics measurements. The main results from this new and dynamic research area will be presented. The application of these findings to astrophysical challenges, ranging from the equation of state of neutron stars to the search for dark matter in space, will be discussed.

Speaker: Alexander Kalweit (CERN)
• 16:30 16:50
Break 20m
• 16:50 18:50
Invited talks
Convener: Shashikant Dugad (Tata Institute of Fundamental Research)
• 16:50
Recent results from LHCb for astroparticle physics 30m

The LHCb experiment is a general-purpose forward spectrometer and the only LHC experiment with particle identification capabilities in the pseudorapidity range of 2 to 5. LHCb was designed to study heavy flavour production and decay, but also offers great opportunities for the study of forward hadron production in proton-proton and proton-ion collisions, which are of great interest for the simulation of cosmic-ray induced air showers. It has been suggested that the Muon Puzzle in air showers could be solved by a potential change in the relative amount of strangeness or baryon production in the forward region. The high-energy atmospheric neutrino flux dominantly originates from prompt decay of D mesons, which are studied in detail at LHCb, and further provide the world's best constraints on the low-x region of the nuclear gluon PDF. Another unique ability of LHCb is to the measurement of hadron production in fixed-target mode, by injecting gas into the central tracker. This has been used to study anti-proton production in proton-helium collisions, a background for cosmic anti-matter searches, and in a search for intrinsic charm in the nucleon. The successful fixed-target program has been extended. Recent results from LHC relevant for astroparticle physics will be presented and an outlook given on future results.

Speaker: Hans Dembinski (TU Dortmund, Germany)
• 17:20
Very forward particle measurements with LHCf and RHICf 30m

Energetic particle produced in the very forward region of hadronic collisions plays an important role in air shower development induced by high-energy cosmic-rays. However, because of lack of experimental data, there are differences of predictions of production cross-section between hadronic interaction models used in air shower simulations.
LHCf and RHICf experiments were designed to test hadronic interaction models by measuring photons, $\pi^0$s and neutrons at LHC and RHIC. Several operations were performed with pp or pPb collisions at wide collision-energy range from $\sqrt{s}$ = 510 GeV to 13 TeV. In this presentation, we will present the recent results of LHCf and RHICf experiments, for example, test of Feynman scaling law using forward photon data of LHCf and RHICf. Additionally prospects of coming operations will be discussed.

Speaker: Hiroaki Menjo (ISEE, Nagoya University)
• 17:50
Recent results from the TOTEM collaboration at CERN 30m

We will will the recent results from TOTEM concerning the elastic, inelastic and total cross section at 7, 8 and 13 TeV. We will also mention in the detail the measurement of the $pp$ elastic differential $d \sigma/dt$ cross section at 2.76, 7, 8 and 13 TeV. Comparing these mesurements with the D0 $d \sigma/dt$ cross sections in $p \bar{p}$ interactions allows D0 and TOTEM to discover the odderon after combining these results with previous measurements from TOTEM of the total cross section and the rho parameter. We will finsh the presentation by recent measurements from CMS and TOTEM sensitive to quartic anomalous couplings and to the production of axion-like particles.

Speaker: Christophe Royon (The University of Kansas (US))
• 18:20
The MoEDAL Experiment - The LHC's First Dedicated Search Experiment – Results and Future Plans 30m

The unprecedented collision energy of the LHC has opened up a new a new discovery
frontier, where a theory underlying the Standard Model(SM) may yet be revealed. Now that the Higgs boson - the last piece of the SM puzzle - has apparently been discovered, the search for such new phenomena has assumed a key importance. However, the LHC has been running for several years and no signals for physics beyond the Standard Model have been observed. Either this new physics is simply not there, or it is somehow evading detection by the general-purpose LHC experiments, ATLAS and CMS.We will present the current results and future plans of the LHC’s pioneering dedicated search detector, MoEDAL. As far as future plans are concerned we will concentrate onthe new sub-detector MAPP due to be installed for LHC’s Run-3, to enhance the physics reach of MoEDAL. Last, but not least, we will briefly describe an astroparticle extension to MoEDAL called Cosmic-MoEDAL that Is in its planning stage.

Speaker: James Pinfold (University of Alberta (CA))
• 18:50 19:10
Break 20m
• 19:10 20:10
Invited talks
Convener: Pankaj Jain (I.I.T. Kanpur)
• 19:10
Recent results from Belle II 30m

The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $6\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to ultimately record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. With this data set, Belle II will be able to measure the Cabibbo-Kobayashi-Maskawa (CKM) matrix, the matrix elements and their phases, with unprecedented precision and explore flavor physics with $B$ and charmed mesons, and $\tau$ leptons. Belle II has also a unique capability to search for low mass dark matter and low mass mediators. We also expect exciting results in quarkonium physics with Belle II. In this presentation, we will review the latest results from Belle II.

Speakers: Dr Qi-Dong Zhou (Belle II), Qidong Zhou (Nagoya University)
• 19:40
Atmospheric neutrino fluxes for the next generation of neutrino telescopes 30m

Improving the precision of atmospheric neutrino flux predictions has been always challenging. Due to more sophisticated data analysis techniques and growing exposure of large volume Cherenkov telescopes (such as IceCube), progress will eventually hit a wall since flux uncertainties may become the dominant systematic uncertainty. The tool MCEq has resolved several problems for the high-energy flux calculations. MCEq almost entirely eliminated the uncertainty related to the method of solving the one-dimensional cascade equations. But the flux prediction will only remain as certain as the combination of cosmic ray flux and hadronic interaction model used in the calculation. In this talk, I will present recent advances in parameterizing hadronic interactions for atmospheric lepton flux calculations, discuss which particle production phase space is probed by the different lepton flux observations, and lay out path toward achieving a sub-10% uncertainty over almost the entire energy range probed by large volume neutrino telescopes.

Speaker: Anatoli Fedynitch (Institute of Physics , Academia Sinica)
• 20:10 21:10
Contributed talks
Convener: Pankaj Jain (I.I.T. Kanpur)
• 20:10
Uncertainty in mean Xmax from diffractive dissociation estimated using measurements of accelerator experiments 15m

Mass composition is important to understand the origin of ultra-high energy cosmic rays. In air shower experiments, the mass composition is estimated by comparing measurements of $\langle X_{\rm max}\rangle$ and its predictions by simulations. However, interpretation of the mass composition from the comparison is challenging due to large uncertainty in hadronic interactions. One of the sources of uncertainty is diffractive dissociation since its measurements at accelerator experiments show large systematic uncertainty.
In this work, we estimated uncertainty in $\langle X_{\rm max}\rangle$ from systematic uncertainty of accelerator experiments. We estimated using an air shower simulation package CONEX and considering the definition of diffractive dissociation in each measurement.
By considering measurements by the ALICE experiment at LHC, uncertainty in <Xmax> was estimated to be $^{+4.0}_{-5.6} \mathrm{g/cm^2}$.

Speaker: Ken Ohashi (Nagoya Univ.)
• 20:25
Limits to gauge coupling in the dark sector set by the non-observation of instanton-induced decay of Super-Heavy Dark Matter in the Pierre Auger Observatory data 15m

We present a thorough search for signatures that would be indicative of decaying super-heavy particles in the Pierre Auger Observatory data. From the lack of signal, we derive upper limits above $\sim 10^8$ GeV on the expected secondary by-product fluxes from $X$-particle decay. Assuming that the energy density of these particles matches that of dark matter, we translate the upper bounds on the particle fluxes into tight constraints on the couplings governing the decay process as a function of the particle mass. We show that instanton-induced decay processes allow us to derive a bound on the reduced coupling constant of gauge interactions in the dark sector: $\alpha_X < 0.09$, for $10^{10} < M_X/{\rm GeV} < 10^{16}$. In the context of super-heavy dark matter produced during the reheating epoch, viable regions are presented in terms of $M_X$, $\alpha_X$, the Hubble rate at the end of inflation, the reheating efficiency, and the non-minimal coupling of the Higgs with curvature.

Speaker: Olivier Deligny (CNRS/IN2P3 -- IJCLab)
• 20:40
On the way to solving the mystery of the long-flying cosmic ray hadrons 15m

A phenomenon of abnormally weak absorption of very high energy cosmic-ray hadrons in lead is discussed. Dedicated experiments with two-storied XRECs, which are sensitive to the production of charmed hadrons in the forward kinematic region (x_{Lab} ≳ 0.1), have been carried out, first, at the Tien Shan and, recently, at the Pamirs in order to prove that the effect of abnormal absorption of hadrons results from rapid increase of charm production cross section with energy which nowadays is observed in collider experiments in central kinematic region. If the charm production cross section is as high as σ_{pp→cc̄} ~ 8 mb at energies <E_{Lab}> ~ 75 TeV, then computer modelling of chamber response makes it possible to reproduce main features of experimental hadron-absorption curves observed both with uniform and two-storied XRECs.

Speaker: Dr Alexander Borisov (P.N.Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia)
• 20:55
Dual-polarized directional antenna for inclined air-shower detection 15m

In this work, we present a dual-polarized directional antenna for registration detection of air- showers created by ultra-high energy cosmic rays arriving from high zenith angles. The first prototype based on Yagi-Uda antenna was designed to detect radio emission in the frequency range of 55-65 MHz. A comparison of radiation patterns, frequency range and noise level at the Tien Shan High Mountain Cosmic Rays Station (~3340 m a.s.l.) and at the University altitude (Almaty, ~880 m a.s.l.) is presented. The developed prototype can be used for the next-generation arrays located in high-mountain areas at aimed at the detection of ultra-high energy cosmic rays and skimming neutrinos. Dual-polarized directional antenna for inclined air-shower detection.

Speaker: Mr Saken Shinbulatov
• Tuesday, 24 May
• 14:30 16:30
Special session: Muon puzzle: Experiment
Convener: Prof. Karl-Heinz Kampert (University of Wuppertal)
• 14:30
Muon measurements with the Pierre Auger Observatory 25m

The Pierre Auger Observatory is the world's largest research facility dedicated to the study of ultra-high-energy cosmic rays. One of its most notorious results is the apparent muon excess with respect to the simulation predictions, which indicates weaknesses in the description of hadronic interactions. In this presentation, I will report the latest measurement results from Auger on the extensive air shower muon content. I will also put these results in perspective with other shower quantities being measured at the observatory and the corresponding implications for hadronic interaction models. Finally, the prospects for future measurements will be presented.

Speaker: Ruben Conceição (LIP/IST)
• 14:55
Results from recent analysis of KASCADE-Grande data 25m

KASCADE and its extension array of KASCADE-Grande were devoted to measure individual air showers of cosmic rays in the primary energy range of 100 TeV to 1 EeV. The experiment has substantially contributed to investigate the energy spectrum and mass composition of cosmic rays in the transition region from galactic to extragalactic origin of cosmic rays as well as to quantify the characteristics of hadronic interaction models in the air shower development through validity tests using the multi-detector information from KASCADE-Grande. Although the data accumulation was completed in 2013, data analysis is still continuing. Recently, we investigated the reliability of the new hadronic interactions models of the SIBYLL version 2.3d with the data from KASCADE-Grande. The evolution of the muon content of high energy air showers in the atmosphere is studied as well. In this talk, recent results from KASCADE-Grande and the update of the KASCADE Cosmic Ray Data Centre (KCDC) will be discussed.

Speaker: Donghwa Kang
• 15:20
Muon puzzle in inclined muon bundles detected by NEVOD-DECOR 25m

The data of cosmic ray experiment NEVOD-DECOR on the investigation of inclined muon bundles for a long time (May 2012 - March 2021) are presented. The analysis showed that the observed intensity of muon bundles at primary cosmic ray energies of about 1 EeV and higher can be compatible with the expectation in frame of widely used hadron interaction models only under the assumption of an extremely heavy mass composition. This conclusion is consistent with data of several experiments on investigations of air shower muon content, but contradicts the available fluorescence data on Xmax which favor a light mass composition at these energies. In order to clarify the nature of the "muon puzzle", investigations of the muon bundle energy deposit in the detector material were carried out. For the first time, experimental estimates of the average energy of muons in the bundles of inclined air showers initiated by primary particles with energies from 10 to 1000 PeV have been obtained.

Speaker: Aleksei Bogdanov (National Research Nuclear University MEPhI (Moscow Engineering Physics Institute))
• 15:45
Muons in showers with energy E0 ≥ 5 EeV and QGSjetII-04 and EPOS LHC models of hadronic interactions. Is there a muon deficit in the models? 15m

The paper presents data on the muon component with a threshold εthr ≥ 1 GeV. Showers were registered at the Yakutsk array during almost 50 years of continuous EAS observations. The characteristics of muons are compared with calculated QGSjetII-04 and EPOS LHC for a proton and an iron nucleus. There is a muon deficit in the models, at energies greater than 5 EeV. To make an agreement between experimental data and simulations on muons, further tuning of the models is required.

Speaker: Stanislav Knurenko (Yu. G. Shafer Institute of Cosmophysical Research and Aeronomy)
• 16:00
Cosmic Ray Measurements with IceCube and IceTop 30m

IceCube is a cubic-kilometer Cherenkov detector in the deep ice at the geographic South Pole. The dominant event yield in the deep ice detector consists of penetrating atmospheric muons with energies above approximately 300 GeV, produced in cosmic ray air showers. In addition, the surface array, IceTop, measures the electromagnetic component and GeV muons of an air shower. Hence, IceCube and IceTop yield unique opportunities to study cosmic rays with unprecedented statistics in great detail.

We will present recent results of comic ray measurements from IceCube and IceTop. In this overview, we will highlight measurements of the energy spectrum of cosmic rays from 250 TeV up to the EeV range and their mass composition above 3 PeV. We will also report recent results from an analysis of the density of GeV muons observed in IceTop and discuss their consistency with predictions from current hadronic interaction models.

Speaker: Dennis Soldin (University of Delaware)
• 16:30 16:50
Break 20m
• 16:50 17:50
Special session: Muon puzzle: Theory
Convener: Prof. Anatoly Petrukhin (MEPhI)
• 16:50
Core-corona effect and air showers 30m

The deficit of muons in the simulation of extensive air showers is a long standing problem and the origin of large uncertainties in the reconstruction of the mass of the high energy primary cosmic rays. Hadronic interaction models re-tuned after early LHC data have less spread in the description of the muon content but still disagree with data. Because of its different ratio of electromagnetic to hadronic energy, a QGP used in a wide phase space may have the properties to solve the muon puzzle in particular in the view of the most recent LHC data. Indeed at LHC a core-corona approach as done in the EPOS hadronic interaction model allows a precise description of the particle yield as a function of multiplicity in pp, pA and AA collisions. It is demonstrated that using a similar approach in all hadronic models, the muon production in air shower can be modified such that experimental data could be reproduced without using exotic physics.

Speaker: Tanguy Pierog (KIT, IKP)
• 17:20
UHE hadronic interactions in air showers, Sibyll and the muon puzzle 30m

In recent years it has become more and more clear that simulations of air showers of ultra-high energy cosmic rays do not agree with measurements when it comes to observables related to muons. The usual explanation is that hadronic interactions are misrepresented in the models that enter the simulations. Using the example of Sibyll, one of the models for hadron interactions used in air shower simulations, I will discuss the processes that are directly related to muon production in air showers, how the production of muons was changed by the data from LHC experiments, how we will gain from future measurements and how we hope to solve the muon puzzle.

Speaker: felix riehn (universidade de santiago de compostela)
• 18:00 19:00
Public lecture
Convener: Sunil Kumar Gupta (Tata Institute of Fundamental Research)
• 18:00
Atmospheric Neutrino Oscillations 1h
Speaker: Takaaki Kajita (ICRR, The University of Tokyo)
• 19:00 19:10
Break 10m
• 19:10 19:40
Special session: Muon puzzle: Theory
Convener: Ralph Engel (KIT)
• 19:10
Peering into the hadronic component of extensive air showers 30m

In this contribution I will review several aspects of the hadronic component of EAS and how the cosmic ray measurements constrain the phase-space of parameters in hadronic models to solve the muon puzzle. The fluctuations of the hadronic cascade, the universality of the relevant distributions, the scaling rules of the different sub-component and finally the coupling to the electromagnetic cascade.

Speaker: Lorenzo Cazon (IGFAE - USC)
• 19:40 20:10
Special session: Muon puzzle: Panel discussion
Convener: Ralph Engel (KIT)
• 19:40
Muon puzzle: Panel discussion 30m

Ralph Engel (Chair), Hans Dembinski, Anatoli Fedynitch, Sergei Ostapchenko, and session speakers

• 20:10 21:10
Contributed talks
Convener: Ralph Engel (KIT)
• 20:10
EUSO-SPB2: A sub-orbital cosmic ray and neutrino multi-messenger pathfinder observatory 15m

The next generation of ultra-high energy cosmic ray (UHECR) and very-high energy neutrino observatories should address the challenge of the extremely low fluxes of these particles at the highest energies. EUSO-SPB2 (Extreme Universe Space Observatory on a Super Pressure Balloon 2) is designed to prepare space missions to address this challenge. EUSO-SPB2 is equipped with 2 telescopes: the Fluorescence Telescope, which will point downwards and measure fluorescence emission from UHECR air showers, and the Cherenkov Telescope (CT), which will point towards the Earth limb and measure direct Cherenkov emission from cosmic rays with energies above 1PeV, verifying the technique. Pointed below the limb, the CT will search for Cherenkov emission produced by neutrino-sourced tau-lepton decays above 10PeV energies and study backgrounds for such events. The EUSO-SPB2 mission will provide pioneering observations and technical milestones on the path towards a space-based multi-messenger observatory.

Speaker: Johannes Eser (The University of Chicago)
• 20:25
The Tunka-Grande scintillation array: current results. 15m

The Tunka-Grande experiment is a scintillation array with about 0.5 sq.km sensitive area at Tunka Valley, Siberia, for measuring charged particles and muons in extensive air showers (EASs). Tunka-Grande is optimized for cosmic ray studies in the energy range 10 PeV to about 1 EeV, where exploring the composition is of fundamental importance for understanding the transition from galactic to extragalactic origin of cosmic rays. This contribution attempts to provide a synopsis of the current results of the experiment. In particular, the reconstruction of the all-particle energy spectrum in the range of 10 PeV to 1 EeV based on experimental data from four observation seasons is presented.

Speaker: Mrs Anna Ivanova (Novosibirsk State University, Irkutsk State University)
• 20:40
The Telescope Array Low-energy Extension Hybrid Detector 15m

The Telescope Array (TA) is the largest cosmic ray observatory in the northern hemisphere. The Telescope Array Low-energy Extension (TALE) experiment was added to the TA in order to extend the energy threshold of the TA measurement down to 10$^{16}$ eV. The TALE has a hybrid air shower detector for observations of air showers induced by cosmic rays in the atmosphere. The TALE consists of a Fluorescence Detector (FD) station with 10 telescopes located adjacent to the TA Middle Drum FD Station (comprised of 14 telescopes) and a Surface Detector (SD) array comprised of 80 scintillation counters, including 40 of which at 400 m spacing and the other 40 at 600 m spacing. In this contribution, we present the measurements of the cosmic ray energy spectrum and mass composition using approximately 2 years of the TALE hybrid data. In addition, we will report the progress of further expanding our experiment for the hybrid detector sensitivity down to $\sim$ 10$^{15}$ eV.

Speaker: Keitaro Fujita (Institute for Cosmic Ray Research, University of Tokyo)
• 20:55
The global cosmic ray observatory - GCOS 15m

The Global Cosmic Ray Observatory - GCOS is an initiative for a next-generation ground-based cosmic-ray observatory, building on the expertise of the Telescope Array and the Pierre Auger project. With the goal of reaching an exposure of at least $2\times 10^5$ km$^2$ yr in a period of 10 years and full-sky coverage a set of surface arrays with a total area of about 40 000 km$^2$ is anticipated. Identification of the ultra-high-energy particle sources will require a good angular resolution ($<0.5^\circ$). For a determination of the fine structures in the energy spectrum, GCOS is expected to provide an energy resolution around $10-15\%$ above an energy of 1~EeV. Another important requirement for the GCOS design is to have the capability to identify the mass of each ultra-high energy particle measured. This requires a good measurement of the atmospheric depth of the shower maximum $X_{max}$ and of the ratio of the electromagnetic to muonic particles in an air shower.

Speaker: Prof. Jorg Horandel (Radboud University)
• Wednesday, 25 May
• 14:30 16:30
Invited talks
• 14:30
New Experiments at the LHC 30m

Up and until run-2, which finished in November 2018, seven experiments were actively taking data at the Large Hadron Collider (LHC), in Geneva Switzerland. In the last few years several proposals for new experiments have been discussed and pursued. Four of these proposals have meanwhile been accepted, and have been, or are now being, installed in the underground areas, and will take data during the run-3 of the LHC which starts in summer this year and will last until end 2025. These new experiments are FASER(Nu), SND@LHC, MilliQan and MAPP. Several other experiments prepare for reviewing and aim to have a detector ready for the HL-LHC run starting after the next long shutdown in 2028/29. Many of these new experiments target in particular searches for new long lived particles, but also have QCD studies on their programme and some, like MATHUSLA, would also have a interesting sensitivity to address cosmic ray questions. In this talk I will give an overview of the different new experiment proposals and discuss their physics goals, with special attention to the topics relevant for this symposium.

Speaker: Albert De Roeck (CERN)
• 15:00
Looking forward to forward physics at the LHC 30m

For decades, new physics searches in collider have focused on the high-$p_T$ region. However, it has recently become evident that the LHC physics potential has not been fully exploited. To be specific, forward collisions, which produce particles along the beamline with enormous rates, have been almost completely ignored. For all practical purposes, these collisions are a treasure trove of physics, containing the highest-energy neutrinos ever produced by humans, as well as possible evidence for dark matter, light and weakly-coupled particles, and new forces. In the upcoming LHC Run 3 the ForwArd Search ExpeRiment (FASER) and its cousin FASER$\nu$ will extend the LHC's physics potential. A continuation of this forward physics program for the HL-LHC aims at the Forward Physics Facility (FPF), with larger scale experiments. In this talk, I will give an overview of the physics motivations for FASER, FASER$\nu$, and the FPF, including both Standard Model and beyond Standard Model physics.

Speaker: Prof. Luis Anchordoqui (City University of New York)
• 15:30
CORSIKA 8 - the next-generation air shower simulation framework 30m

For more than 20 years, the community has heavily relied on CORSIKA for the simulation of extensive air showers, their Cherenkov light emission and their radio signals. While tremendously successful, the Fortran-based monolithic design of CORSIKA up to version 7 limits adaptation to new experimental needs, for example in complex scenarios where showers transition from air into dense media, and to new computing paradigms such as the use of multi-core and GPU parallelization. With CORSIKA 8, we have reimplemented the core functionality of CORSIKA in a modern, modular, C++-based simulation framework, and successfully validated it against CORSIKA 7. In this contribution, I will discuss the philosophy of CORSIKA 8, showcase some example applications, and discuss the current state of implementation as well as the plans for the future.

Speaker: Tim Huege (Karlsruhe Institute of Technology)
• 16:00
Cosmic ray interactions in the atmosphere: QGSJET-III and other models 30m

I shall discuss the physics content of the QGSJET-III Monte Carlo generator
of high energy hadronic collisions, concentrating on the new developments and
comparing to alternative approaches of other cosmic ray interaction models.
Further, I shall consider calculated characteristics of cosmic ray induced
extensive air showers (EAS), comparing the corresponding results of QGSJET-III
with the ones of other models. In particular, I shall demonstrate that the
differences between the predicted EAS characteristics are mostly driven by
deficiencies of certain models.

Speaker: Sergey Ostapchenko (Hamburg University, II. Institute for Theoretical Physics)
• 16:30 16:50
Break 20m
• 16:50 17:50
Invited talks
• 16:50
INO 30m
Speaker: D Indumathi (The Institute of Mathematical Sciences, Chennai)
• 17:20
The TAIGA - an advanced hybrid detector complex for astroparticle physics, cosmic ray physics and gamma-ray astronomy 30m

The physical motivations and performance of the TAIGA project are presented. The TAIGA complex addresses ground-based gamma-ray astronomy at energies from a few TeV to several PeV, as well as cosmic ray physics from 0.10 TeV to 1 EeV. The pilot TAIGA-1 complex locates in the Tunka valley, ~50 km from the lake Baikal. It includes integrating air Cherenkov TAIGA-HiSCORE array with 120 wide-angle Chrenkov stations distributed over on area 1.1 square kilometer and three the 4-m class Imaging Atmospheric Cherenkov Telescopes of the TAIGA-IACT array.m. In the report discusses installations of TAIGA complex, approaches to detecting gamma-rays in our experiment and calibration methods. An overview of the main results in the field of gamma-ray astronomy, cosmic ray physics and additional areas will be made. A future TAIGA -10, 10 sq.km installation, based on the wide angle Cherenkov array and small size wide angle imaging telescopes will be also discussed.

Speaker: Prof. Nikolay Budnev (Irkutsk State University)
• 17:50 18:50
Contributed talks
• 17:50
Measuring the attenuation length of muon number in the air shower with LHAASO muon detector 15m

LHAASO KM2A consists of thousands scintillation detectors and 1188 muon detectors, and the muon detectors cover 4% area of the whole array with 30 m space. The muon number of air showers events, with very high energy (PeVs), is investigated with the data recorded by LHAASO muon detector in 2021. The attenuation length of muon number in the air shower is measured by fitting the muon number with constant flux in various zenith angles, based on the constant intensity cut method. The attenuation length varying with the primary energy of incident particle is studied also. For comparison, the attenuation length of simulation data, measured with same method, also will be present for two high energy hadronic models QGSJET-II-04 and EPOS-LHC.

Speaker: Xiaoting Feng (LHAASO)
• 18:05
Overview of quarkonium production with ALICE at the LHC 15m

ALICE is a general purpose experiment designed to investigate nucleus-nucleus
collisions at the Large Hadron Collider (LHC), located at CERN. At forward ra-
pidity the ALICE detector is optimized for the measurement of muon pairs. The
main focus is the study of quarkonium production as a probe of the quark-gluon
plasma (QGP), a deconfined state of nuclear matter, formed in nucleus-nucleus col-
lisions. In addition to these studies, reference measurements in proton-proton and
proton-nucleus collisions are carried out. The latter measurements contribute to a
better understanding of charm production at forward rapidity at high energies and
of parton densities at very low Bjorken x.
In this contribution, quarkonium measurements with ALICE at forward rapidity
for various energies and colliding systems (pp, p–Pb and Pb–Pb) will be discussed
and compared to theory.

Speaker: Dr Hushnud Hushnud (Aligarh Muslim University)
• 18:20
Proton Penetration Efiiciency over HIgh Altitude Observatories 15m

In association with a large solar flare on November 7, 2004, the solar neutron detectors located at Mt. Chacaltaya (5,250m) in Bolivia and Mt. Sierra Negra (4,600m) in Mexico have recorded very interesting events. In order to explain these events, we have performed a calculation solving the equation of motion of anti-protons. Being based on these results, we will demonstrate that the Chacaltaya event observed in the energy range of 100-1000MeV and the Mt. Sierra Negra event observed in the energy range > 6,000MeV, stem from the same origin. The Mt. Chacaltaya event can be explained by the detection of solar neutrons, while the Mt. Sierra Negra event is explained by the first detection of such high energy solar neutron decay protons (SNDPs) as 6GeV.

Speaker: Prof. Yasushi Muraki (Professor of Emeritus)
• 18:35
New determination of the production cross section for secondary positrons and electrons in the Galaxy 15m

The cosmic-ray fluxes of electrons and positrons ($e^{\pm}$) are measured with high precision by the space-borne particle spectrometer AMS-02. To infer a precise interpretation of the production processes for $e^{\pm}$ in our Galaxy, it is necessary to have an accurate description of the secondary component, produced by the interaction of cosmic-ray proton and helium with the interstellar medium atoms.
We determine new analytical functions of the Lorentz invariant cross section for the production of $\pi^\pm$ and $K^\pm$ by fitting data from collider experiments. We also evaluate the invariant
cross sections for several other channels, involving for example hyperon decays, contributing at the few % level on the total cross section.
The total differential cross section $d\sigma/dT_{e^\pm}(p+p\rightarrow e^\pm+X)$ is predicted from 10 MeV up to 10 TeV of $e^\pm$ energy with an uncertainty of about 5-7% in the energies relevant for AMS-02 positron flux.

Speaker: Luca Orusa
• 18:50 19:10
Break 20m
• 19:10 21:10
Contributed talks
• 19:10
The all-particle energy spectrum of cosmic rays from 10 TeV to 1 PeV measured with HAWC 15m

One of the main scientific goals of the HAWC collaboration is the study of cosmic rays in the energy interval from 10 TeV to 1 PeV. The HAWC observatory is an air shower detector well suited for the research of cosmic rays in this energy region, and it can provide a bridge between the data from space-borne to ground-based cosmic-ray detectors. This work presents an update of the all-particle cosmic-ray energy spectrum between 10 TeV and 1 PeV obtained from the analysis of two years of HAWC's data, which was collected from January, 2018 to December, 2019, and an unfolding method. For the calibration and the energy estimation, we employed the high-energy hadronic interaction model QGSJET-II-04. The results show the presence of a knee-like structure around tens of TeVs, which was previously reported by the HAWC collaboration in 2017.

Speaker: Jorge Antonio Morales-Soto (Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo)
• 19:25
On irregularities in the cosmic ray spectrum of 10^{16}-10^{18} eV range 15m

Small, medium and large arrays for the study of cosmic rays of ultra-high energies existing are aimed at obtaining information about our Galaxy and metagalactic space. Concretely search and study of astronomical objects, that forms flux of relativistic particles that fill outer space. The drift and interaction of such particles with magnetic field and shock waves taking place in interstellar space causes the same interest. The shape of the energy spectrum of cosmic rays in the energy range 10^{15}-10^{18} eV, where “knee” and “second knee” is observed, can be formed as a superposition of the partial spectra of various chemical elements. Verification of galactic models, using recent experimental spectral data, makes it possible to study the nature of the galactic and metagalactic components of cosmic rays. The paper presents the result of the energy spectrum of cosmic rays in the range 10^{16}-10^{18} eV measurements obtained at the Small Cherenkov array – a part of the Yakutsk array.

Speaker: Igor Petrov (Yu. G. Shafer Institute of Cosmophysical Research and Aeronomy)
• 19:40
Hadronic Interaction Model Dependence in Cosmic Gamma-ray Flux Estimation Using Ground-based Air Shower Array with Underground Water Cherenkov muon detector array 15m

For sub-PeV gamma-ray observation in the southern sky, a new experiment (ALPACA) using a ground-based air shower detector array (AS) and underground muon detector array (MD) is underway in the middle of Mt. Chacaltaya, Bolivia. A smaller prototype experiment (ALPAQUITA), a part of ALPACA, is under construction. The hybrid experiment with AS + MD enables us to distinguish between muon-poor gamma-ray air showers and muon-rich cosmic-ray air showers. We report on hadronic interaction model dependence in estimating the gamma-ray flux by the gamma-ray/cosmic-ray separation method.
We clarify the characteristics of air shower muons generated by a MC simulation with some hadronic interaction models and their model differences using vertical gamma-ray air showers at the ALPACA altitude (4,740 m). Then we evaluate the model-dependence in the detection efficiency of gamma rays by the gamma-ray/cosmic-ray separation method in the energy range from a few TeV to several hundred TeV with ALPAQUITA.

Speaker: sosuke okukawa
• 19:55
Point sources of ultra-high-energy neutrinos: minimalist predictions for near-future discovery 15m

The detection of ultra-high-energy neutrinos, with energies above 100 PeV, is key to fully understand the high-energy Universe. Their discovery might soon be within reach of upcoming neutrino telescopes. We present a robust framework to compute the statistical significance of source discovery via the detection of neutrino multiplets. As a benchmark experiment, we focus on the radio array component of IceCube-Gen2, but our framework can be adapted to other neutrino telescopes. Our methods are experiment-based, conservative, and comprehensive, accounting for non-neutrino backgrounds, neutrino attenuation inside the Earth, and the angular response of the detector. To identify a source with $5\sigma$ significance, IceCube-Gen2 will need to detect a triplet, at best, and an octuplet, at worst, depending on whether the source is steady-state or transient, and on its position in the sky. The number of discovered sources can significantly constrain the properties of the source population.

Speaker: Damiano Fiorillo (Niels Bohr International Academy, Niels Bohr Institute,4 University of Copenhagen, 2100 Copenhagen, Denmark)
• 20:10
Probing hadronic interaction models with the hybrid data of the Pierre Auger Observatory 15m

Presently large systematic uncertainties remain in the description of hadronic interactions at ultra-high energies, and a fully consistent description of air-shower experimental data is yet to be reached. The amount of data collected by the Pierre Auger Observatory using simultaneously the fluorescence and surface detectors in the energy range 10^18.5-10^19.0 eV has provided an opportunity to study adjustments to model predictions. We apply a global method to simultaneously determine the mass composition of cosmic rays, modifications of the simulated Xmax, and modifications of hadronic signals at ground level. The data-driven results of the method prefer a deeper scale of simulated Xmax than predicted by hadronic interaction models tuned to the LHC data. Consequently, the mass composition of the primary species was found to be heavier, and the deficit of the simulated hadronic signal at ground level, dominated by muons, is alleviated compared to unmodified hadronic interaction models.

Speaker: Dr Jakub Vicha (FZU - Institute of Physics of the Czech Academy of Sciences)
• 20:25
The use of PYTHIA for nucleus-nucleus interactions in CORSIKA simulations 15m

One of the possible ways to solve the "Muon Puzzle" is the introduction of a new physical process of muon generation in high energy nucleus-nucleus interactions. The well-known generator PYTHIA provides such possibility. But it cannot be used for the interactions of nuclei in CORSIKA via predefined program settings. Therefore, the interface between two programs was developed. To check the applicability of PYTHIA for EAS simulations, it was compared with four main high energy hadron models implemented in CORSIKA. The comparison of the yield of secondary particles and the distribution of the energy between them was performed to see the individual features of each model. The scheme of the interface between CORSIKA and PYTHIA is described. The comparison of the results of EAS simulations with and without PYTHIA interface is discussed.

Speaker: Roman Nikolaenko
• 20:40
On connection between the collider long-range near-side "ridge" effect at $|\eta| < 2.4$ and cosmic-ray coplanarity of most energetic particles 15m

Some coplanarity of most energetic subcores of γ-ray--hadron families is observed in cosmic-ray experiments at $E_0 ≳ 10^{16}$ eV ($\sqrt{s} ≳ 5$ TeV). This effect requires appearance of some coplanar generation of most energetic particles in hadron-nucleus interactions .
On the other hand, a long-range near-side "ridge" effect was observed in pp collisions at $\sqrt{s}=7$ TeV by the CMS Collaboration in two-particle Δη - Δφ correlation functions at Δη ≳ 3 and Δφ ≈ 0. To improve a research for possible relationship of these phenomena, a phenomenological FANSY 2.0 model is designed to simulate hadron interactions using both traditional and coplanar modes for the hadron generation, QGSJ and CPG, respectively. Model parameters of coplanar hadron generation are given. It is shown that the FANSY 2.0 CPG reproduces the near-side "ridge" effect, which may be nothing more than a by-product of the coplanar generation of the most energetic hadrons.

Speaker: Prof. Rauf Mukhamedshin (INR RAS)
• 20:55
Dark matter searches through correlations of the gamma-ray sky with neutral hydrogen, cosmic voids and galaxies surveys 15m

Dark matter (DM) is expected to produce signals originating from its particle nature, among which the electromagnetic emission represents a relevant opportunity. However, this emission is very faint and contributes only to the unresolved background radiation. Since this radiation originates from DM haloes, it will be correlated to the matter distribution in the Universe.
We propose to use neutral hydrogen intensity mapping as a tracer of the matter distribution, and gamma rays as a tracer of DM annihilation. Intensity mapping (IM) offers excellent redshift information since it measures a line emission and it has the advantage of not being flux limited in the measurement of the matter distribution, as opposed to galaxy surveys, since it does not need to resolve individual galaxies. We show the expected signal from this cross-correlation channel and we forecast constraints through the combination of Fermi-LAT gamma-ray data and the next-generation radio telescope Square Kilometre Array.

Speaker: Elena Pinetti (Fermilab)
• Thursday, 26 May
• 14:30 16:30
Invited talks
• 14:30
Selected MAGIC Results at TeraelectronVolt Energies 30m

About a quarter of century ago the MAGIC telescope project defined it’s goal to extend the observational energy range of very high energy gamma rays by using the ground-based imaging air Cherenkov technique from a few hundred down to few tens of GeV. Closing the order of magnitude energy gap between the satellite and ground-based observational techniques and providing real-time high-detection rates of gamma-rays from diverse celestial sources as, for example, from pulsars, distant AGN and GRBs, was considered of key importance. The telescopes were designed to receive satellite alerts and automatically re-position within 20-25 seconds and observe any chosen type of source at any given position in the sky. Most of these design features were implemented in the hope to measure TeV gamma-rays from GRBs, hopefully still in the prompt emission phase. With time we learnt to further enhance the sensitivity of the telescopes and measure sources as in the few tens of GeV as well as at a few hundred TeVs. In this report we will dwell on selected interesting results of the MAGIC collaboration during recent years.

Speaker: Razmik Mirzoyan (Max-Planck-Institute for Physics)
• 15:00
VERITAS highlights of observations and results 30m

Located in Southern Arizona, VERITAS is amongst the most sensitive detectors for astrophysical very high energy (VHE; E>100 GeV) gamma rays and has been operational since April 2007. In this talk, some recent results from VERITAS observations will be presented. These include the observations of the Galactic Center, Supernova Remnant Cas A, and IC 443, and long-term observations of the gamma-ray binaries HESS J0632+057 and LS I +61° 303. The results from a decade of multi-wavelength observations of the blazar 1ES 1215+303, the EHT 2017 campaign of M87 galaxy, the discovery of 3C 264 in VHE energies, and the observation of three flaring quasars will also be shown. We also discuss the observations of dwarf spheroidal galaxies, one of the most favorable target classes for putting constraints on dark matter. VERITAS also devotes a significant part of its observing time to Targets-of-Opportunity, allowing for the follow-up of multi-messenger alerts and astrophysical transients.

Speaker: Sonal Ramesh Patel (Deutsches Elektronen-Synchrotron DESY)
• 15:30
The HAWC observatory in view of the second decade of the 21st century: An Overview and Current Results 30m

A new and unique universe at energies greater than 50 TeV has been unveiled within high energy astrophysics in the XXI century. Since its operations in 2013, HAWC has contributed significantly to this field in the band of 100 GeV to 100 TeV. HAWC is located at 4100 meters above sea level on the slope of the Sierra Negra volcano, Mexico. It is composed of an array of 300 Cherenkov Water Detectors (the primary detector), surrounded by 350 small support detectors or outriggers. It has a wide field-of-view (~2 sr) and a high duty cycle (> 95%), which makes it well-suited to perform all-sky surveys. In this talk, I present an overview of the HAWC observatory, emphasizing its contributions and remarking on TeV Halos objects and PeVatrons.

Speaker: Dr Eduardo de la Fuente Acosta (Universidad de Guadalajara y HAWC Observatory)
• 16:00
An update on the MACE gamma-⁠ray telescope 30m

Major Atmospheric Cherenkov Experiment (MACE) is an Imaging Atmospheric Cherenkov Telescope (IACT) located at Indian Astronomical Observatory, Hanle, India. The main objective of the MACE telescope is to lower the threshold energy upto 30 GeV which is crucial, yet unexplored energy band. In order to achieve this goal, the telescope was built in an altitude of ~4300 meters, which makes MACE as the highest altitude IACT in the world. However, accomplishing this lower energy threshold demands more indigenous developments of various subsystems like parabolic reflector, camera, and drive system. In this talk, we will review the unique features, relevance and current status of the MACE telescope.

Speaker: Dr Nijil Mankuzhiyil (BARC Mumbai)
• 16:30 16:50
Break 20m
• 16:50 18:50
Invited talks
• 16:50
Direct Measurements of Cosmic Rays with the CALorimetric Electron Telescope on the International Space Station 30m

The CALorimetric Electron Telescope, CALET, has been measuring high-energy cosmic rays on the International Space Station. The scientific objectives are to search for possible nearby sources of high-energy electrons and potential signatures of dark matter, and to investigate the details of galactic cosmic-ray acceleration and propagation. The calorimetric instrument, which is 30 radiation lengths thick and fine imaging capability, is optimized to measure cosmic-ray electrons by achieving large proton rejection and excellent energy resolution well into the TeV region. In addition, very wide dynamic range of energy measurement and individual charge identification capability enable us to measure proton and nuclei spectra from a few tens GeV to a PeV scale. Using the data obtained over 6.5 years of operation, we will present a brief summary of the CALET observation including electron spectrum, and proton and nuclei spectra as well as the performance study on-orbit with MC simulations.

Speaker: Yosui Akaike (Waseda University)
• 17:20
Latest results from the AMS experiment 30m
Speaker: Prof. Samuel Ting (Massachusetts Institute of Technology)
• 17:50
Status and Prospect of Cosmic Ray Energy Spectrum Measured by LHAASO 30m

Large High-Altitude Air Shower Observatory (LHAASO) has one square kilometer array of scintillator detectors and muon detectors (KM2A), 18 Wide Field of View Imaging Atmospheric Cherenkov Telescopes (WFCTA) and a 78,000 square meter Water Cherenkov Detector Array (WCDA). LHAASO is located at very high altitude (around 4410 m a.s.l.) in Haizishan mountain, Daocheng, Sichuan, China. Multi-parameter observation of showers allows to measurement the energy spectrum, elemental composition and anisotropy with high resolution, which give us an excellent opportunity to understand the origin, acceleration and propagation of ultra-high energy cosmic rays. The 1/4, 1/2, 3/4 and full array of LHAASO experiment have started running in September 2019, in January 2020, in December 2020 and July 2021 respectively. Preliminary results and the prospect of the energy spectrum, elemental composition measured by LHAASO experiment will be presented.

Speaker: Shoushan Zhang (Institute of High Energy Physics)
• 18:20
Cherenkov Telescope Array : Current Status 30m

The Cherenkov Telescope Array (CTA) will be the next generation ground-based very-high-energy (VHE) imaging Cherenkov gamma ray telescope array. CTA will consist of telescopes of different sizes (Large, Medium & Small), which will be distributed in two locations, one in La Palma, Spain and one in Chile, and has been designed to detect VHE gamma rays in the energy range 20 GeV to 300 TeV. These VHE gamma rays are produced under extreme conditions in the Universe in the vicinity of supermassive black holes, neutron stars and due to shock acceleration caused by supernovae. CTA will have a sensitivity at least an order of magnitude better compared to existing telescopes. The first LST (Large Size Telescope) is already installed and is being commissioned at La Palma. In this talk I will present the current status of CTA and discuss key science goals.

Debanjan Bose for the CTA Consortium

Speaker: Dr Debanjan Bose (S.N. Bose National Centre for Basic Sciences)
• 18:50 19:10
Break 20m
• 19:10 21:10
Contributed talks
• 19:10
A measurement of the proton plus helium spectrum of cosmic rays in the TeV region with HAWC 15m

HAWC is an air-shower detector designed to study TeV gamma and cosmic rays. The observatory is composed of a 22000 $m^2$ array of 300 water Cherenkov tanks (4.5 m deep x 7.3 m diameter) with 4 photomultipliers (PMT) each. The instrument registers the number of hit PMTs, the timing information and the total charge at the PMTs during the event. From these data, shower observables such as the arrival direction, the core position at ground, the lateral age and the primary energy are estimated. In this work, we study the distribution of the shower age vs the primary energy of a sample of shower data collected by HAWC from June 2015 to June 2019 and employ a shower-age cut based on predictions of QGSJET-II-04 to separate a subsample of events dominated by H and He primaries. Using these data and a dedicated analysis, we reconstruct the cosmic ray spectrum of H+He from 6 to 158 TeV, which shows the presence of a softening at around 24 TeV with a statistical significance of 4.1$\sigma$.

Speaker: Juan Carlos Arteaga-Velazquez (Universidad Michoacana de San Nicolas de Hidalgo)
• 19:25
On the primary spectrum of the hadronic PeVatron candidate HAWC J1825-134 15m

The HAWC Collaboration has recently reported on the observation of $\gamma$ rays beyond 200 TeV from the direction of the Galactic source HAWC J1825-134 [Albert et al., ApJ Lett., 907, L30 (2021)]. This source is among the best candidates for hadronic PeVatrons (the objects that are able to accelerate protons at least up to 1 PeV= 10^{15} eV). We dissect the region around the HAWC J1825-134 source and derive the upper limits on the intensity of the source in the 1 GeV--1 TeV energy range using publicly available data of the Fermi-LAT space $\gamma$-ray telescope. Only a very hard ($\gamma_{p} < 1.7$) primary proton spectrum at $E_{p}$<10 TeV describes the Fermi-LAT data set well. A simple $\propto E_{p}^{-\gamma_{p}}e^{-E_{p}/E_{p-c}}$ spectrum could in principle describe the combined HAWC and Fermi-LAT data sets well for $\gamma_{p} \approx 1.5$ and $E_{p-c} \approx 500$ TeV. More details could be found in [Dzhatdoev et al., ApJ, 929, 25 (2022)].

Speakers: Timur Dzhatdoev (Moscow State University), Mr Egor Podlesnyi (Institute for Nuclear Research)
• 19:40
The composition of cosmic rays according to the data on EAS cores. 15m

The only way to solve problem of knee is to determine the composition of CRs. The conclusions of this work are based on the analysis of the characteristics of the EAS cores obtained using X-ray emulsion chambers. According to these data, a number of anomalous effects are observed in the knee region, such as an increase in the absorption length of hadron showers, a scaling violation in the spectra of secondary hadrons, an excess of muons in EAS with gamma families, a violation of isotopic invariance, the appearance of halos and the alignment of energy centers along a straight line. At the same energies equivalent to 1-100 PeV the laboratory system colliders show scaling behavior. So analysis of the data on the EAS cores suggests that the knee in their spectrum is formed by a component of cosmic rays of a non-nuclear nature, possibly consisting of stable (quasi-stable) particles of hypothetical strange quark matter.

Speaker: Prof. Sergey Shaulov (FIAN)
• 19:55
Results on high energy galactic cosmic rays from the DAMPE space mission 15m

DAMPE (Dark Matter Particle Explorer), is a satellite-born experiment launched in 2015 in a sun-synchronous orbit at 500 km altitude, and it is taking data in a stable way ever since. Its main goals include the spectral measurements on cosmic electrons/positrons, protons and nuclei and gamma rays, up to very high energies.

Its main features include the 32 radiation lengths deep calorimeter and the large geometric acceptance, making DAMPE one of the most powerful instruments ever sent to space to cover with high statistics and small systematics the high energy frontier up to several hundreds TeV.

The results of different species spectral measurements will be shown and discussed.

Speaker: Leandro Silveri (Gran Sasso Science Institute, Italy)
• 20:10
GRAINE project: balloon-borne sub-GeV/GeV gamma ray telescope with nuclear emulsion 15m

The observation of cosmic gamma-rays is crucial for understanding high-energy astrophysical phenomena. Fermi-LAT launched in 2008 was used to survey the sub-GeV/GeV gamma-ray sky, and the high statistics measurements brought many new insights. On the other hand, the results showed that the precise observation with high angular resolution is needed for making more progress in cosmic gamma-ray observation.
We promote the GRAINE project, which pertains to the precise observation of cosmic gamma rays in the 10MeV–100GeV region using a balloon-borne telescope with a nuclear emulsion chamber. The telescope has high angular resolution(1.0° at 100 MeV, 0.1° at 1GeV, this is about an order of magnitude higher than Fermi-LAT) and polarization sensitivity. GRAINE plans to observe with an aperture area of 10 m2 repeatedly.
We will show a performance of a demonstration experiment in 2018 and preparation status of next experiment in 2023. We will start the scientific observation from it.

Speaker: Dr Yuya Nakamura (Nagoya University)
• 20:25
Primary Cosmic Rays Energy Spectrum and Mean Mass Composition by the Data of the TAIGA Astrophysical Complex 15m

The new analysis of the EAS Cerenkov light LDF both experimental and MC simulated is described. It led us to the conclusion of more deep position of $X_{max}$ in the energy range $10^{15}$ - $10^{17}$ eV and adequately more light mean mass composition that it seemed before. The new correlations between Cherenkov light fluxes at the core distances 100 m and 200 m and primary energy were obtained for different zenith angles and light composition (protons and helium). The primary energy spectrum, obtained from the data of the Tunka-133 and the TAIGA-HiSCORE arrays, in the energy range $1.5\cdot 10 ^{14}$ – $10^{18}$ eV, based on these new correlations will be presented.

Speaker: Prof. Vasily Prosin (SINP MSU)
• 20:40
The ALPACA experiment: The project of the first sub-PeV gamma-ray observation in the southern sky 15m

The ALPACA experiment is a project aiming to observe sub-PeV gamma rays for the first time in the southern sky. The main goal of ALPACA is to identify PeVatrons, the accelerators of Galactic PeV cosmic rays, by observing sub-PeV pion-decay gamma rays generated in interactions between PeV cosmic rays and the interstellar medium. This new air shower experiment is located at an altitude of 4,740 m above sea level in the middle of Mt. Chakartaya in Bolivia. The air shower array consists of 401 scintillation counters covering an 83,000 m^2 surface area. In addition, a water-Cherenkov-type muon detector array with an area of 3,700 m^2 is installed to discriminate gamma rays from background cosmic rays. The prototype array ALPAQUITA will start data taking in 2022 and will extend to half-ALPACA, which has the half-density array of ALPACA in 2023. In this symposium, a general introduction to ALPACA, the progress of the project, and the sensitivity to sub-PeV gamma rays are presented.

Speaker: Teruyoshi Kawashima (ICRR, The University of Tokyo)
• 20:55
Constraining ultra-high-energy cosmic ray composition through cross-correlations 15m

The chemical composition of the highest end of the ultra-high-energy cosmic ray spectrum is very hard to measure experimentally, and to this day it remains mostly unknown. Since the trajectories of ultra-high-energy cosmic rays are deflected in the magnetic field of the Galaxy by an angle that depends on their atomic number Z, it could be possible to indirectly measure Z by quantifying the amount of such magnetic deflections. In this paper we show that, using the angular harmonic cross-correlation between ultra-high-energy cosmic rays and galaxies, we could effectively distinguish different atomic numbers with current data. As an example, we show how, if Z=1, the cross-correlation can exclude a 39% fraction of Fe56 nuclei at 2σ for rays above 100EeV.

Speaker: Dr Konstantinos Tanidis (Central European Institute for Cosmology and Fundamental Physics)
• Friday, 27 May
• 14:30 16:30
Invited talks
• 14:30
Results from the ARIANNA high-energy neutrino detector 30m

Ultra-high-energy (UHE) neutrinos with energies above a few $10^{16}$ eV can be measured with in-ice radio detectors. This is explored in the ARIANNA experiment, with shallow detector stations on the Ross Ice Shelf and the South Pole. I will present recent results that lay the foundation for future large-scale experiments. I will show a limit on the UHE neutrino flux derived from ARIANNA data, measurements of the more abundant air showers, results from in-situ measurement campaigns, and give an outlook of future detector improvements.

Speaker: Christian Glaser (Uppsala University)
• 15:00
The KM3NeT infrastructure: status and first results 30m

KM3NeT is a research infrastructure in construction deep at the bottom of the Mediterranean Sea at two sites. It hosts two large volume neutrino telescopes: ARCA at a depth of 3500 m, offshore Capo Passero in Sicily (Italy) and ORCA, offshore Toulon (France), at a depth of 2500 m. The two telescopes use the same technology, data acquisition system and detection principle, the only difference is the density of the optical modules, depending on the energy region of interest for the two detectors. ARCA is a sparse lattice of multi-photomultiplier optical modules, instrumenting a volume of water of about 1 km3. Its main goal is the search for cosmic neutrinos. ORCA has a denser structure and is optimized to collect atmospheric neutrinos and measure their oscillation patterns in order investigate neutrino properties, like neutrino mass hierarchy. This contribution discusses the scientific perspectives of KM3NeT, describes the status of the construction and presents some preliminary results.

Speaker: Annarita Margiotta
• 15:30
Neutrinos from near and far: Results from the IceCube Neutrino Observatory 30m

Instrumenting a gigaton of ice at the geographic South Pole, the IceCube Neutrino Observatory has been at the forefront of groundbreaking scientific discoveries over the past decade. These include the observation of a flux of TeV-PeV astrophysical neutrinos, detection of the first astrophysical neutrino on the Glashow resonance and evidence of the blazar TXS 0506+056 as the first known astronomical source of high-energy neutrinos. Several questions, however, remain, pertaining to the precise origins of astrophysical neutrinos, their production mechanisms at the source and in Earth’s atmosphere and in the context of physics beyond the Standard Model. In this talk I highlight some of our latest results, from new constraints on neutrino interactions and oscillations to the latest measurements of the astrophysical neutrino flux and searches for their origins to future prospects with IceCube Gen2.

Speaker: Tianlu Yuan (University of Wisconsin Madison)
• 16:00
Neutrino-Matter interactions at TeV energies and above 30m

The interpretation of the ultra-high-energy neutrino-matter scattering events collected at large volume particle detectors crucially relies on theoretical knowledge of the underlying scattering process. I will discuss recent theoretical progress on our understanding of this topic, focussing on the multi-TeV and PeV neutrino energy range which is relevant for cosmic neutrino measurements. In addition, I will highlight areas where further theoretical work is needed to improve the sensitivity of future measurements of both cosmic and atmospheric neutrinos.

Speaker: Rhorry Gauld (University of Bonn)
• 16:30 16:50
Break 20m
• 16:50 18:50
Invited talks
• 16:50
Astroparticle and Particle physics with Air Showers: results from the Pierre Auger Observatory 30m

The scientific achievements of the Pierre Auger Collaboration cover diverse and complementary fields of research. The search for the origin of ultra-high energy cosmic rays (UHECRs) is based on the measurement of the energy spectrum and mass composition of the primaries, on studies of other neutral messengers, photons and neutrinos, and on extensive anisotropy searches at both large and intermediate angular scales. In addition to astrophysical studies, with the collected data it is possible to explore the characteristics of hadronic interactions at energies unreachable at accelerators, and to assess the existence of non-standard physics effects, such as possible Lorentz invariance violations, or signals of super-heavy dark matter. In this contribution, a selection of the latest results is presented, starting from the quest for the sources of UHECRs to then focus in particular on hadronically-sensitive shower observables and their comparisons with model predictions. Finally, the expected contribution of the ongoing upgrade AugerPrime of the Observatory will be discussed.

Speaker: Antonella Castellina (INAF/INFN Torino, Italy)
• 17:20
Highlights from the Telescope Array Experiment 30m

The Telescope Array is the largest hybrid cosmic ray detector in the Northern hemisphere designed to measure primary particles in 4 PeV to 100 EeV range. TA is a hybrid detector. The main TA detector consists of 507 plastic scintillation counters on a 1.2km square grid and and fluorescence detectors at three stations overlooking the sky above the surface detector array. Since its completion in 2018, the TA Low energy Extension (TALE) hybrid detectors, which consists of an additional ten fluorescence telescopes and 80 infill surface detectors with 400m and 600 m spacing, has continued to provide long term stable observations. The TAx4, a plan to quadruple the detection area of TA is also ongoing, and some of the detectors continue to operate stably as hybrid detectors. I review the present status of the experiments and most recent physics results on the cosmic ray anisotropy, chemical composition and energy spectrum.

Speaker: Hiroyuki Sagawa (Institute for Cosmic Ray Research, the University of Tokyo)
• 17:50
The full coverage approach to the detection of Extensive Air Showers 30m

A shower array exploiting the full coverage approach with a high segmentation of the readout allow to image the front of atmospheric showers with unprecedented resolution and detail. The grid distance determines the low energy threshold (small energy showers are lost in the gap between detectors) and the quality of the shower sampling.
Therefore, this experimental solution is needed to detect showers with a threshold in the hundreds GeV range.
The full coverage approach has been exploited in the ARGO-YBJ experiment. In this contribution we will summarise the advantages of this technique and discuss possible applications in new wide field of view detectors.

Speaker: Giuseppe Di Sciascio
• 18:20
Latest results from the Tibet ASgamma experiment 30m

The Tibet air shower (AS) array and underground water-Cherenkov-type muon detector (MD) array have been successfully operated since 2014, at an altitude of 4,300m in Tibet, China. Our air shower simulation reproduces gamma-ray as well as cosmic-ray data from the AS and MD arrays. The hybrid experiment will be useful not only for the gamma-ray observation, but also for the energy spectrum measurement in the knee energy region. The energy and arrival direction are determined by the Tibet AS array, while we count number of muons in an air shower with the MD array 2.4 m underground. For example, the MD array enables us to suppress more than 99.9% of background cosmic rays against gamma rays above 100 TeV.In this presentation, we will report on the gamma-ray detection techniques and the latest results from the Tibet ASgamma experiment.

Speaker: Dr Masato Takita (Institute for Cosmic Ray Research, The University of Tokyo)
• 18:50 19:10
Break 20m
• 19:10 19:40
Invited talks
• 19:10
Highlights of the results from the GRAPES-3 experiment 30m

The GRAPES-3 is a unique extensive air shower experiment consisting of 400 scintillator detectors spread over an area of 25000 m$^2$ and a 560 m$^2$ muon telescope. The experiment located at Ooty, India has been collecting data for the past two decades. The unique capabilities of GRAPES-3 have allowed the study of cosmic rays over energies from a few TeV to tens of PeV and beyond. The measurement of the directional flux of muons (E$_\mu$$\geq1 GeV) by the large muon telescope permits an excellent gamma-hadron separation to be made which then in turn becomes a powerful tool in the study of multi-TeV \gamma-ray sources and the composition of primary cosmic rays. However, the high precision measurements also enable studies of transient atmospheric and interplanetary phenomena such as those produced by the thunderstorms and geomagnetic storms. In this talk some of the exciting new recent results would be presented and updates provided on various ongoing analyses. Speaker: Dr Hari Haran B (Tata Institute of Fundamental Research) • 19:40 20:40 Contributed talks • 19:40 Updated results on the cosmic ray energy spectrum and composition from the GRAPES-3 experiment 15m Here, we present the updated results on the cosmic ray energy spectrum and composition analysis from the GRAPES-3 experiment over the energy range of 50 TeV to 1000 TeV since ICRC 2021. The simulation of cosmic ray showers was performed using the post-LHC high energy hadronic interaction model QGSJetII-04 and low energy hadronic model FLUKA. The composition of the primary cosmic rays was assumed from the composition models such as H4A and GST. A detailed GEANT4 simulation of the GRAPES-3 muon telescope was performed, and a comparison study for lateral density distribution of observed muons with simulation has exhibited a very good agreement. The composition was also obtained by fitting simulated muon multiplicity distributions for proton, helium, nitrogen, aluminium, and iron primaries to the observed data. The energy spectrum connects to the direct measurements with a fairly good agreement in flux. Speaker: Fahim Varsi (Indian Institute of Technology, Kanpur) • 19:55 Update on the angular resolution of GRAPES-3 experiment based on Moon shadow analysis 15m Moon creates a shadow in the isotropic cosmic ray flux by blocking them along its direction. The Moon shadow method is used to calibrate the angular resolution and pointing accuracy of air shower arrays. The GRAPES-3 is an extensive air shower array located at Ooty (11.6^\circN, 76.7^\circE, 2200 m asl) in southern India. The angular resolution of the GRAPES-3 array was improved by correcting the shower front curvature based on the shower size and age. Here, we present the results of the angular resolution and pointing accuracy of the array through observation of Moon shadow. We have analyzed the data for the period of 2014-2016 containing \sim$$3\times10^9$ air shower events with a median energy of 15 TeV. A significant improvement in the angular resolution has been observed compared to the earlier analysis by the group through Moon shadow method and are comparable to the arrays located at 2 km higher altitude.

Speaker: DIPTIRANJAN PATTANAIK (Cosmic Ray Laboratory, TIFR-Ooty)
• 20:10
DEASA STUDIES AND APPLICATIONS TO SPACE PHYSICS AND MUON TOMOGRAPHY 15m

DEASA (Dayalbagh Educational Air Shower Array) consisting of eight plastic scintillators each with an area of 1 square meter, has been set up. This array covers an area of 260 square meters and is the first array in the northern part of our country. The cosmic ray shower has been simulated in CORSIKA for the different primary particles in the energy range of 1014- 1015 eV. In this case, the longitudinal and lateral profile has been studied for Agra (168 m above sea level).
The real-life applications of the cosmic ray particles in which the effect of cosmic rays in space has been studied and the best material has been found to protect the astronaut from the galactic cosmic rays [1].
A method to scan the radioactive container has also been studied with the help of Monte-Carlo simulations (Geant4) which is called muon tomography. In this study, a dry cask container has been simulated which contains the UO2 rods and the muon scattering has been observed. [2]

Speaker: Dr Sonali Bhatnagar (Dayalbagh Educational Institute)
• 20:25
Mass testing of SiPMs for the CMVD at IICHEP 15m

A Cosmic Muon Veto (CMV) detector is being built around the mini-Iron Calorimeter (mini-ICAL) detector at the transit campus of the India based Neutrino Observatory, Madurai. The CMV detector will be made using extruded plastic scintillators with embedded wavelength shifting (WLS) fibres which emitted photons of longer wavelengths and propagate those to silicon photo-multipliers (SiPMs). The SiPMs detect these scintillation photons, producing electronic signals. The CMV detector will require more than 700 scintillators and about 3000 SiPMs for the readout to shield the mini-ICAL detector. The design goal for the cosmic muon veto efficiency of the CMV is $>$99.99\% and fake veto rate less than 10$^{-5}$. A testing system was developed, using an LED driver, to measure the noise rate and gain of each SiPM, and thus determine its overvoltage ($V_{ov}$). The test results and the analysed characteristics of about 3.5k SiPMs will be presented in this paper.

Speaker: Ms Mamta Jangra (Tata Institute of Fundamental Research)
• 20:40 21:10
Closing ceremony