Publications

Order by: publication date number of citations

• Measuring the attenuation length of muon number in the air shower with muon detectors of 3/4 LHAASO array

  Xiaoting Feng, Hengying Zhang, Cunfeng Feng, Lingling Ma on behalf of the LHAASO Collaboration

  SciPost Phys. Proc. 13, 017 (2023) · published 28 September 2023 | Toggle abstract · pdf

  LHAASO KM2A consists of 5915 scintillation detectors and 1188 muon detectors, and the muon detectors cover 4% area of the whole array with 30 m interdetector spacing. The muon number in air shower events, with very high energy, is investigated with the data recorded by muon detector of the 3/4 LHAASO array 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 variation of the attenuation length as shower energy from hundreds TeV to tens PeV is presented. The results of simulation also is presented for comparing.

• Exploring neutrino masses and mixing in the seesaw model with $L_e-L_\tau$ gauged symmetry

  Papia Panda, Mitesh Kumar Behera, Priya Mishra, Shivaramakrishna Singirala, Rukmani Mohanta

  SciPost Phys. Proc. 16, 024 (2025) · published 15 July 2025 | Toggle abstract · pdf

  We investigate neutrino phenomenology in the $U(1)_{L_e-L_\tau}$ gauge extension of the Standard Model with symmetry following the framework of type-(I+II) seesaw mechanism. For this, we have added three right handed neutrinos, one singlet and one scalar triplet in our model. We show that the model can successfully accommodate the observed neutrino oscillation data and consistent with the results from lepton flavor violation and neutrinoless double beta decay process.

• A measurement of the proton plus helium spectrum of cosmic rays in the TeV region with HAWC

  Juan Carlos Arteaga-Velázquez on behalf of the HAWC collaboration

  SciPost Phys. Proc. 13, 015 (2023) · published 28 September 2023 | Toggle abstract · pdf

  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$\sigma$.

• A continuum determination of the strong isospin-breaking contribution to the muon anomalous magnetic moment

  Kim Maltman, Christopher James, Randy Lewis

  SciPost Phys. Proc. 16, 031 (2025) · published 15 July 2025 | Toggle abstract · pdf

  First-principles lattice determinations of the Standard Model expectation for the leading order hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon have become sufficiently precise that further improvement requires including strong and electromagnetic isospin-breaking effects. We provide a continuum estimate of the strong isospin-breaking contribution, $a_\mu^{SIB}$, using $SU(3)$ chiral perturbation theory. The result is shown to be dominated by resonance-region contributions encoded in a single low-energy constant whose value is known from flavor-breaking hadronic $\tau$ decay sum rules. Implications of the form of the result for lattice determinations of $a_\mu^{SIB}$ are also discussed.

• $e^+e^-$ hadronic cross-sections with SND detector at VEPP 2000

  T. V. Dimova, M. N. Achasov, A. Yu. Barnyakov, K. I. Beloborodov, A. V. Berdyugin, A. G. Bogdanchikov, A. A. Botov, V. P. Druzhinin, L. V. Kardapoltsev, A. G. Kharlamov, A. A. Korol, D. P. Kovrizhin, A. S. Kupich, N. A. Melnikova, A. E. Obrazovsky, E. V. Pakhtusova, K.V. Pugachev, S. I. Serednyakov, D. A. Shtol, Z. K. Silagadze, I. K. Surin, Yu. V. Usov, V. N. Zhabin

  SciPost Phys. Proc. 16, 014 (2025) · published 14 July 2025 | Toggle abstract · pdf

  Data with an integrated luminosity of about 370 pb$^{-1}$ have been collected with the SND detector at the VEPP-2000 $e^+e^-$ collider. Here we present recent results on $e^+e^-$ annihilation into hadrons below 2 GeV based on a part of these data. In particular, we discuss measurements of the $e^+e^-\to \pi^+\pi^-$, $e^+e^- \to n\bar{n}$, $e^+e^- \to p\bar{p}$, and $e^+e^-\to \pi^+\pi^-\pi^0\pi^0$ cross sections, and study of the processes $e^+e^-\to \pi^+\pi^-\pi^0$, $e^+e^-\to K^+K^-\pi^0$, $e^+e^- \to \eta\pi^0 \gamma$, and $e^+e^- \to \eta \eta \gamma$.

• Colouring the Higgs boson

  Andy Buckley, Giuseppe Callea, Andrew J. Larkowski, Simone Marzani

  SciPost Phys. Proc. 10, 001 (2022) · published 10 August 2022 | Toggle abstract · pdf

  The jet colour ring is a novel colour tagger observable designed to separate the decay of a colour-singlet into two jets from a two-jet background in a different colour configuration. Simulation studies in the case of the production of a boosted Higgs boson decaying in two b-quarks and an associate electroweak boson, showed notable discriminator powers when comparing the jet colour ring performances with other observables. These results are opening a wide scenario for further studies.

• The scattering and neutrino detector at the LHC

  Giovanni De Lellis

  SciPost Phys. Proc. 12, 051 (2023) · published 5 July 2023 | Toggle abstract · pdf

  SND@LHC, Scattering and Neutrino Detector at the LHC, is a compact experiment designed to perform measurements with neutrinos produced at the LHC in the unexplored pseudo-rapidity region of 7.2 < $\eta$ < 8.4, complementary to all the other experiments at the LHC. The experiment was approved in March 2021. It was constructed in about one year and it is now taking data during the Run 3 of the LHC. In this paper we review the detector concept, the physics case and the status of the data taking.

• Adiabatic and irreversible classical discrete time crystals

  Adrian Ernst, Anna M. E. B. Rossi, Thomas M. Fischer

  SciPost Phys. 13, 091 (2022) · published 11 October 2022 | Toggle abstract · pdf

  We simulate the dynamics of paramagnetic colloidal particles that are placed above a magnetic hexagonal pattern and exposed to an external field periodically changing its direction along a control loop. The conformation of three colloidal particles above one unit cell adiabatically responds with half the frequency of the external field creating a time crystal at arbitrary low frequency. The adiabatic time crystal occurs because of the non-trivial topology of the stationary manifold. When coupling colloidal particles in different unit cells, many body effects cause the formation of topologically isolated time crystals and dynamical phase transitions between different adiabatic reversible and non-adiabatic irreversible space-time-crystallographic arrangements.

• Probing hadronic interactions with measurements from the Pierre Auger Observatory

  B. Andrada

  SciPost Phys. Proc. 10, 005 (2022) · published 10 August 2022 | Toggle abstract · pdf

  The Pierre Auger Observatory is the largest facility in the world to study ultra-high-energy cosmic rays. It has a hybrid detection technique that combines the observation of the longitudinal development of extensive air showers and the measurement of their particles at the ground. This capability has opened the possibility to probe hadronic interactions taking place at energies well beyond those accessible by human-made accelerators. In this report, we present a selection of the latest results on hadronic interactions with measurements from the Pierre Auger Observatory. These data span over three decades in energy, showing the tension between data from the muon component of air showers and predictions based on the most updated hadronic interaction models.

• Critical behavior of a phase transition in the dynamics of interacting populations

  Thibaut Arnoulx de Pirey, Guy Bunin

  SciPost Phys. 18, 051 (2025) · published 13 February 2025 | Toggle abstract · pdf

  Many-variable differential equations with random coefficients provide powerful models for the dynamics of many interacting species in ecology. These models are known to exhibit a dynamical phase transition from a phase where population sizes reach a fixed point, to a phase where they fluctuate indefinitely. Here we provide a theory for the critical behavior close to the phase transition. We show that timescales diverge at the transition and that temporal fluctuations grow continuously upon crossing it. We further show the existence of three different universality classes, with different sets of critical exponents, highlighting the importance of the migration rate coupling the system to its surroundings.