The particle showers produced in the atmosphere due to the interactions of primary cosmic particles require a thorough understanding in the backdrop of searches for rare interactions. In this work, we made a comprehensive study of air shower simulations using various combinations of hadronic models and particle transport code of the CORSIKA package. The primary proton and helium distributions are taken as power law which are scaled to match the measured flux in balloon experiments at the top of atmosphere. The shower simulation includes production, transport, and decays of secondaries up to the ground level. In this study, we focus on the bulk of the spectra and particles which is computationally intensive and hence parallel processing of events is done on computer cluster. We provide a way to normalize the simulation results to be compared with the ground-based measurements namely, single and multiple muon yields and their charge ratios as a function of zenith angle and momentum. This provides a basis for comparisons among the six model combinations used in this study and the differences are outlined. Most of the hadronic models in CORSIKA produce the bulk ground based measurements fairly well. We use one of the best model combinations to quantitatively predict the absolute and relative yields of various particles at ground level as well as their correlations with primaries and with each other. The leptonic ratios are obtained as a function of energy and zenith angle which are important inputs for the neutrino oscillation physics.
Muons and neutrinos from cosmic ray interactions in the atmosphere originate from decays of mesons in air-showers. Sibyll-2.3c aims to give a precise description of hadronic interactions in the relevant phase space for conventional and prompt leptons in light of new accelerator data, including that from the LHC. Sibyll is designed primarily as an event generator for use in simulation of extensive air showers. Because it has been tuned for forward physics as well as the central region, it can also be used to calculate inclusive fluxes. The purpose of this paper is to describe the use of Sibyll-…
Possible difference between multiplicity distributions and inclusive spectra of secondary hadrons in proton-proton and proton-antiproton collisions at energy sqrt(s)=900 GeV
最常用的辐射能量损失形式是在高能近似下导出的.在目前的形式，它是可靠的，只有中等修改的包容性粒子谱。对这种形式主义的修改，预计将是重要的包容性较低的测量。这对于重离子碰撞中的重建喷流尤其重要，因为这种方法最近才开始出现。我们提出了一些想法，以克服这一限制。具体来说，我们展示了一个实施中的喷射部分子簇射辐射能量损失。该实现已在PYTHIA Monte Carlo事件生成器中完成。我们提出了公开可用的常规Q-PYTHIA和讨论所获得的一些物理结果。
The phenomenon of fully coherent energy loss (FCEL) in the collisions of protons on light ions affects the physics of cosmic ray air showers. As an illustration, we address two closely related observables: hadron production in forthcoming proton-oxygen collisions at the LHC, and the atmospheric neutrino fluxes induced by the semileptonic decays of hadrons produced in proton-air collisions. In both cases, a significant nuclear suppression due to FCEL is predicted. The conventional and prompt neutrino fluxes are suppressed by $\sim 10...25\%$ in their relevant neutrino energy ranges. Previous es…
Decays of mesons produced in cosmic ray induced air showers in Earth's atmosphere can lead to a flux of light exotic particles which can be detected in underground experiments. We evaluate the energy spectra of the light neutral mesons $π^0$, $η$, $ρ^0$, $ω$, $ϕ$ and $J/ψ$ produced in interactions of cosmic ray protons and helium nuclei with air using QCD inspired event generators. Summing up the mesons produced in the individual hadronic interactions of air showers, we obtain the resulting fluxes of undecayed mesons. As an application, we re-consider the case of millicharged particles created…
We present a new calculation for the production of isolated photon pairs at the LHC with NNLL$'_{\mathcal{T}_0}$+NNLO accuracy. This is the first implementation within the GENEVA Monte Carlo framework of a process with a nontrivial Born-level definition which suffers from QED singularities. Throughout the computation we use a smooth-cone isolation algorithm to remove such divergences. The higher-order resummation of the 0-jettiness resolution variable $\mathcal{T}_0$ is based on a factorisation formula derived within Soft-Collinear Effective Theory which predicts all of the singular, virtual a…
Enhanced Cosmic-Ray Antinuclei Fluxes with Dark Matter Annihilation into SUEPs
Istituto Nazionale di Fisica Nucleare, Sezione di Torino（意大利国家核物理研究所都灵分部）；University of Wisconsin, Madison（威斯康星大学麦迪逊分校）；Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin, Madison（威斯康星大学麦迪逊分校威斯康星冰立方粒子天体物理中心）；University of Toronto（多伦多大学）；Institute for Fundamental Science and Department of Physics, University of Oregon（俄勒冈大学基础科学与物理系）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Department of Physics, University of Torino（都灵大学物理系）
