Air Shower Physics
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A Branching Model for Hadronic Air Showers Vladimir Novotny
A branching model for hadronic air showers Vladimir Novotny∗ Charles University, Faculty of Mathematics and Physics, Institute of Particle and Nuclear Physics, Prague, Czech Republic E-mail: [email protected] Dalibor Nosek Charles University, Faculty of Mathematics and Physics, Institute of Particle and Nuclear Physics, Prague, Czech Republic E-mail: [email protected] Jan Ebr Institute of Physics of the Academy of Sciences of the Czech Republic, Prague, Czech Republic E-mail: [email protected] We introduce a simple branching model for the development of hadronic showers in the Earth’s atmosphere. Based on this model, we show how the size of the pionic component followed by muons can be estimated. Several aspects of the subsequent muonic component are also discussed. We focus on the energy evolution of the muon production depth. We also estimate the impact of the primary particle mass on the size of the hadronic component. Even though a precise calcu- lation of the development of air showers must be left to complex Monte Carlo simulations, the proposed model can reveal qualitative insight into the air shower physics. arXiv:1509.00364v1 [astro-ph.HE] 1 Sep 2015 The 34th International Cosmic Ray Conference, 30 July- 6 August, 2015 The Hague, The Netherlands ∗Speaker. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/ A branching model for hadronic air showers Vladimir Novotny 1. Introduction We study a hadronic component of extensive air showers. Key parameters that we want to determine are a shape of a muonic subshower profile and an atmospheric depth of its maximum µ µ (Xmax). -
Selfconsistent Description of Vector-Mesons in Matter 1
Selfconsistent description of vector-mesons in matter 1 Felix Riek 2 and J¨orn Knoll 3 Gesellschaft f¨ur Schwerionenforschung Planckstr. 1 64291 Darmstadt Abstract We study the influence of the virtual pion cloud in nuclear matter at finite den- sities and temperatures on the structure of the ρ- and ω-mesons. The in-matter spectral function of the pion is obtained within a selfconsistent scheme of coupled Dyson equations where the coupling to the nucleon and the ∆(1232)-isobar reso- nance is taken into account. The selfenergies are determined using a two-particle irreducible (2PI) truncation scheme (Φ-derivable approximation) supplemented by Migdal’s short range correlations for the particle-hole excitations. The so obtained spectral function of the pion is then used to calculate the in-medium changes of the vector-meson spectral functions. With increasing density and temperature a strong interplay of both vector-meson modes is observed. The four-transversality of the polarisation tensors of the vector-mesons is achieved by a projector technique. The resulting spectral functions of both vector-mesons and, through vector domi- nance, the implications of our results on the dilepton spectra are studied in their dependence on density and temperature. Key words: rho–meson, omega–meson, medium modifications, dilepton production, self-consistent approximation schemes. PACS: 14.40.-n 1 Supported in part by the Helmholz Association under Grant No. VH-VI-041 2 e-mail:[email protected] 3 e-mail:[email protected] Preprint submitted to Elsevier Preprint Feb. 2004 1 Introduction It is an interesting question how the behaviour of hadrons changes in a dense hadronic medium. -
Investigation on Gamma-Electron Air Shower Separation for CTA
Taras Shevchenko National University of Kyiv The Faculty of Physics Astronomy and Space Physics Department Investigation on gamma-electron air shower separation for CTA Field of study: 0701 { physics Speciality: 8.04020601 { astronomy Specialisation: astrophysics Master's thesis the second year master student Iryna Lypova Supervisor: Dr. Gernot Maier leader of Helmholtz-University Young Investigator Group at DESY and Humboldt University (Berlin) Kyiv, 2013 Contents Introduction 2 1 Extensive air showers 3 1.1 Electromagnetic showers . 3 1.2 Hadronic showers . 7 1.3 Cherenkov radiation . 11 2 Cherenkov technique 13 2.1 Cherenkov telescopes . 13 2.2 Cherenkov Telescope Array . 18 2.3 Air shower reconstruction . 24 3 γ-electron separation with telescope arrays 31 3.1 Hybrid array . 31 3.2 The Cherenkov Telescope Array . 39 Summary 42 Reference 44 Appendix A 47 Appendix B 50 Introduction Very high energy (VHE) ground-based γ-ray astrophysics is a quite young science. The earth atmosphere absorbs gamma-rays and direct detection is possible only with satellite or balloon experiments. The flux of gamma rays falls rapidly with increasing energy and satellite detectors become not effective anymore due to the limited collection area. Another possibility for gamma- ray detection is usage of Imaging Atmospheric Cherenkov telescopes. The primary γ-ray creates a cascade of the secondary particles which move through the atmosphere. The charged component of the cascade which moves with velocities faster the light in the air, emits Cherenkov light which can be detected by the ground based optical detectors. The ground based gamma astronomy was pioneered by the 10 m single Cherenkov telescope WHIPPLE (1968) [1] in Arizona. -
Astro-Particle Physics: Imaging Air Cherenkov Telescopes (Iacts)
IceAct: Cosmic Ray Air Cherenkov telescopes as an upgrade to the IceCube Neutrino Observatory at the South Pole Larissa Paul, Anna AbadSantos, Antonio Banda, Aine Grady, Sean McLaughlin, Matthias Plum and Karen Andeen Department of Physics, Marquette University, Milwaukee WI, USA Student researchers Astro-particle physics: Imaging Air Cherenkov Telescopes (IACTs): Testing epoxy for the use at the South Pole: at work • Cosmic rays - Particles Source? IACTs detect Cherenkov light produced in the atmosphere by air showers: this The IceAct cameras consist of 61 PMMA Winston cones (WCs) glued onto the with the highest known allows us to study the purely electromagnetic component of the air shower with glass of 61 SiPMs with epoxy. The epoxy used in previous versions of the energy in the universe excellent energy and mass resolution prototype was not cold-rated, causing rapid degradation of the camera at Polar • Discovered in 1912, still a • technique is complementary to the particle detectors already in place at the temperatures. A reliable cold-rated epoxy is vital to ensure many years South Pole of successful data taking. the IceAct lot of unknowns: camera • What are cosmic rays? • will allow us to significantly improve several measurements that we are • What are the astrophysical sources of cosmic interested in through: We are testing two different cold-rated epoxies for rays? • cross-calibrations of the different detector components against each other long-term reliability and reproducibility: • How are they accelerated? • reconstruction of events with different detector configurations • Goal #1: release equal amounts of epoxy drops • Air showers onto each SiPM. Cascades of secondary particles generated by cosmic IceAct: • Problem: viscosity of epoxy changes with time exposed to air, causing the ray particles interacting with the earth's atmosphere. -
Extensive Air Showers and Ultra High-Energy Cosmic Rays: a Historical Review
EPJ manuscript No. (will be inserted by the editor) Extensive Air Showers and Ultra High-Energy Cosmic Rays: A Historical Review Karl-Heinz Kampert1;a and Alan A Watson2;b 1 Department of Physics, University Wuppertal, Germany 2 School of Physics and Astronomy, University of Leeds, UK Abstract. The discovery of extensive air showers by Rossi, Schmeiser, Bothe, Kolh¨orsterand Auger at the end of the 1930s, facilitated by the coincidence technique of Bothe and Rossi, led to fundamental con- tributions in the field of cosmic ray physics and laid the foundation for high-energy particle physics. Soon after World War II a cosmic ray group at MIT in the USA pioneered detailed investigations of air shower phenomena and their experimental skill laid the foundation for many of the methods and much of the instrumentation used today. Soon in- terests focussed on the highest energies requiring much larger detectors to be operated. The first detection of air fluorescence light by Japanese and US groups in the early 1970s marked an important experimental breakthrough towards this end as it allowed huge volumes of atmo- sphere to be monitored by optical telescopes. Radio observations of air showers, pioneered in the 1960s, are presently experiencing a renais- sance and may revolutionise the field again. In the last 7 decades the research has seen many ups but also a few downs. However, the exam- ple of the Cygnus X-3 story demonstrated that even non-confirmable observations can have a huge impact by boosting new instrumentation to make discoveries and shape an entire scientific community. -
Phenomenology of Gev-Scale Heavy Neutral Leptons Arxiv:1805.08567
Prepared for submission to JHEP INR-TH-2018-014 Phenomenology of GeV-scale Heavy Neutral Leptons Kyrylo Bondarenko,1 Alexey Boyarsky,1 Dmitry Gorbunov,2;3 Oleg Ruchayskiy4 1Intituut-Lorentz, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands 2Institute for Nuclear Research of the Russian Academy of Sciences, Moscow 117312, Russia 3Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia 4Discovery Center, Niels Bohr Institute, Copenhagen University, Blegdamsvej 17, DK- 2100 Copenhagen, Denmark E-mail: [email protected], [email protected], [email protected], [email protected] Abstract: We review and revise phenomenology of the GeV-scale heavy neutral leptons (HNLs). We extend the previous analyses by including more channels of HNLs production and decay and provide with more refined treatment, including QCD corrections for the HNLs of masses (1) GeV. We summarize the relevance O of individual production and decay channels for different masses, resolving a few discrepancies in the literature. Our final results are directly suitable for sensitivity studies of particle physics experiments (ranging from proton beam-dump to the LHC) aiming at searches for heavy neutral leptons. arXiv:1805.08567v3 [hep-ph] 9 Nov 2018 ArXiv ePrint: 1805.08567 Contents 1 Introduction: heavy neutral leptons1 1.1 General introduction to heavy neutral leptons2 2 HNL production in proton fixed target experiments3 2.1 Production from hadrons3 2.1.1 Production from light unflavored and strange mesons5 2.1.2 -
Vector Mesons and an Interpretation of Seiberg Duality
Vector Mesons and an Interpretation of Seiberg Duality Zohar Komargodski School of Natural Sciences Institute for Advanced Study Einstein Drive, Princeton, NJ 08540 We interpret the dynamics of Supersymmetric QCD (SQCD) in terms of ideas familiar from the hadronic world. Some mysterious properties of the supersymmetric theory, such as the emergent magnetic gauge symmetry, are shown to have analogs in QCD. On the other hand, several phenomenological concepts, such as “hidden local symmetry” and “vector meson dominance,” are shown to be rigorously realized in SQCD. These considerations suggest a relation between the flavor symmetry group and the emergent gauge fields in theories with a weakly coupled dual description. arXiv:1010.4105v2 [hep-th] 2 Dec 2010 10/2010 1. Introduction and Summary The physics of hadrons has been a topic of intense study for decades. Various theoret- ical insights have been instrumental in explaining some of the conundrums of the hadronic world. Perhaps the most prominent tool is the chiral limit of QCD. If the masses of the up, down, and strange quarks are set to zero, the underlying theory has an SU(3)L SU(3)R × global symmetry which is spontaneously broken to SU(3)diag in the QCD vacuum. Since in the real world the masses of these quarks are small compared to the strong coupling 1 scale, the SU(3)L SU(3)R SU(3)diag symmetry breaking pattern dictates the ex- × → istence of 8 light pseudo-scalars in the adjoint of SU(3)diag. These are identified with the familiar pions, kaons, and eta.2 The spontaneously broken symmetries are realized nonlinearly, fixing the interactions of these pseudo-scalars uniquely at the two derivative level. -
Detection Techniques of Radio Emission from Ultra High Energy Cosmic Rays
Detection Techniques of Radio Emission from Ultra High Energy Cosmic Rays DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Chad M. Morris, B.S. Graduate Program in Physics The Ohio State University 2009 Dissertation Committee: Prof. James J. Beatty, Adviser Prof. John F. Beacom Prof. Richard J. Furnstahl Prof. Richard E. Hughes c Copyright by Chad M. Morris 2009 Abstract We discuss recent and future efforts to detect radio signals from extended air showers at the Pierre Auger Observatory in Malarg¨ue, Argentina. With the advent of low-cost, high-performance digitizers and robust digital signal processing software techniques, radio detection of cosmic rays has resurfaced as a promising measure- ment system. The inexpensive nature of the detector media (metallic wires, rods or parabolic dishes) and economies of scale working in our favor (inexpensive high- quality C-band amplifiers and receivers) make an array of radio antennas an appealing alternative to the expense of deploying an array of Cherenkov detector water tanks or ‘fly’s eye’ optical telescopes for fluorescence detection. The calorimetric nature of the detection and the near 100% duty cycle gives the best of both traditional detection techniques. The history of cosmic ray detection detection will be discussed. A short review on the astrophysical properties of cosmic rays and atmospheric interactions will lead into a discussion of two radio emission channels that are currently being investigated. ii This dissertation is dedicated to my wife, Nichole, who has tolerated and even encouraged my ramblings for longer than I can remember. -
Pos(ICRC2019)270 B † 15%
Air-Shower Reconstruction at the Pierre Auger Observatory based on Deep Learning PoS(ICRC2019)270 Jonas Glombitza∗a for the Pierre Auger Collaboration yb aRWTH Aachen University, Aachen, Germany bObservatorio Pierre Auger, Av. San Martín Norte 304, 5613 Malargüe, Argentina E-mail: [email protected] Full author list: http://www.auger.org/archive/authors_icrc_2019.html The surface detector array of the Pierre Auger Observatory measures the footprint of air show- ers induced by ultra-high energy cosmic rays. The reconstruction of event-by-event information sensitive to the cosmic-ray mass, is a challenging task and so far mainly based on fluorescence detector observations with their duty cycle of ≈ 15%. Recently, great progress has been made in multiple fields of machine learning using deep neural networks and associated techniques. Apply- ing these new techniques to air-shower physics opens up possibilities for improved reconstruction, including an estimation of the cosmic-ray composition. In this contribution, we show that deep convolutional neural networks can be used for air-shower reconstruction, using surface-detector data. The focus of the machine-learning algorithm is to reconstruct depths of shower maximum. In contrast to traditional reconstruction methods, the algorithm learns to extract the essential in- formation from the signal and arrival-time distributions of the secondary particles. We present the neural-network architecture, describe the training, and assess the performance using simulated air showers. 36th International Cosmic Ray Conference — ICRC2019 24 July – 1 August, 2019 Madison, Wisconsin, USA ∗Speaker. yfor collaboration list see PoS(ICRC2019)1177 c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). -
Understanding the Atmosphere As a Calorimeter for UHE Cosmic Rays
SLAC Summer Institute on Particle Physics (SSI04), Aug. 2-13, 2004 Understanding the Atmosphere as a Calorimeter for UHE Cosmic Rays Gerd Schatz∗ Fakultat¨ f¨ur Physik, Universitat¨ Heidelberg This contribution discusses the methods to measure the energies of cosmic rays at the extreme upper end of the spectrum. After a short introduction to calorimetry in high energy physics the most important features of extensive air showers (EASs) are described. An EAS is the phenomenon which develops when a high energy particle enters the atmosphere of the Earth. The two methods of determining the energy in the range where ground based detectors have to be used are then described. The contribution ends with listing some of the unsolved problems in the field. 1. Introduction The observational evidence for ultra high energy cosmic rays and possible ways for accelerating them have been discussed extensively by T. Stanev [1] and R. Blanford [2], respectively. It is the purpose of this contribution to describe and critically review the methods for determining the energy of cosmic ray particles in the energy range where direct detection from high flying balloons or satellites is no more possible and ground-based detector systems have to be used. Any particle entering the atmosphere of the Earth from space is characterized by the following 8 parameters position, direction, time, energy, particle kind The last item is a discrete parameter determining mass and charge of the incident particle. When these parameters have been measured we know everything we can ever hope to know about it. The 6 observables in the first line can be measured with reasonable accuracy and do not present any serious problem. -
PARTICLE DECAYS the First Kaons from the New DAFNE Phi-Meson
PARTICLE DECAYS K for KLi The first kaons from the new DAFNE phi-meson factory at Frascati underline a fascinating chapter in the evolution of particle physics. As reported in the June issue (p7), in mid-April the new DAFNE phi-meson factory at Frascati began operation, with the KLOE detector looking at the physics. The DAFNE electron-positron collider operates at a total collision energy of 1020 MeV, the mass of the phi- meson, which prefers to decay into pairs of kaons.These decays provide a new stage to investigate CP violation, the subtle asymmetry that distinguishes between mat ter and antimatter. More knowledge of CP violation is the key to an increased understanding of both elemen tary particles and Big Bang cosmology. Since the discovery of CP violation in 1964, neutral kaons have been the classic scenario for CP violation, produced as secondary beams from accelerators. This is now changing as new CP violation scenarios open up with B particles, containing the fifth quark - "beauty", "bottom" or simply "b" (June p22). Although still on the neutral kaon beat, DAFNE offers attractive new experimental possibilities. Kaons pro duced via electron-positron annihilation are pure and uncontaminated by background, and having two kaons produced coherently opens up a new sector of preci sion kaon interferometry.The data are eagerly awaited. Strange decay At first sight the fact that the phi prefers to decay into pairs of kaons seems strange. The phi (1020 MeV) is only slightly heavier than a pair of neutral kaons (498 MeV each), and kinematically this decay is very constrained. -
Rho-Meson Self-Energy in Rotating Matter
XJ9900220 E2-99-18 T.I.Gulamov* RHO-MESON SELF-ENERGY IN ROTATING MATTER Submitted to «Physics Letters B» ^Permanent address: Physical and Technical Institute of Uzbek Academy of Sciences, 700084 Tashkent, Uzbekistan 30-29 1999 Introduction. The question of how the hadron properties are modified in hot and dense nuclear matter still attracts close attention of both experimenters and theoretists. The p dynamics is crucially important here because it may be related to observables. In particular, possible modifications of the in-medium p-mesop properties are believed to be seen in the spectra of lepton pairs produced in heavy ion collisions. The commonly expected phenomena are the modification of the effective mass and decay width [1-12]. Another observable is the polarization effect caused by the fact that vector particle could exhibit a different in medium behavior being in different states of polarization [6,8,13]. The physical reason is that the matter has its own four-velocity so that one can distinguish between states polarized longitudinally or transversally with respect to direction of matter motion (equivalently, one can consider the motion of a vector particle while the matter remainss at rest). From statistical physics we know that an equilibrated system may have (apart from the motion as a whole) a rotation. As well as in the case of motion, there is a preferable direction - the one of the angular velocity, so one could distinguish between longitudinal and transverse polarizations withrespect to this direction. The basic question is, whether this state of matter could be realized experimentally, for example, in heavy ion collisions? A possible answer is that peripheral collisions may provide a large momentum transfer whose mean value could be described via introducing the rotation with some value of angular velocity [14].