DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Fγ: A new observable for photon-hadron discrimination in hybrid air shower events

Abstract

To search for ultra-high-energy photons in primary cosmic rays, air shower observables are needed that allow a good separation between primary photons and primary hadrons. In this paper, we present a new observable, Fγ, which can be extracted from ground-array data in hybrid events, where simultaneous measurements of the longitudinal and the lateral shower profile are performed. The observable is based on a template fit to the lateral distribution measured by the ground array with the template taking into account the complementary information from the measurement of the longitudinal profile, i.e. the primary energy and the geometry of the shower. Fγ shows a very good photon-hadron separation, which is even superior to the separation given by the well-known X max observable (the atmospheric depth of the shower maximum). At energies around 1 EeV (10 EeV), Fγ provides a background rejection better than 97.8 % (99.9 %) at a signal efficiency of 50 %. Advantages of the observable Fγ are its technical stability with respect to irregularities in the ground array (i.e. missing or temporarily non-operating stations) and that it can be applied over the full energy range accessible to the air shower detector, down to its threshold energy. Finally and furthermore, Fγ complements nicely to X max such that both observables can well be combined to achieve an even better discrimination power, exploiting the rich information available in hybrid events.

Authors:
 [1];  [1];  [1];  [2];  [3];  [4]
  1. Univ. of Siegen (Germany). Dept. of Physics
  2. Univ. of Siegen (Germany). Dept. of Physics; Univ. of Paris (France). Lab. of Nuclear and High-Energy Physics (LPNHE)
  3. Univ. of Siegen (Germany). Dept. of Physics; Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  4. Univ. of Siegen (Germany). Dept. of Physics; Inst. of Technologies in Detection and Astroparticles, Buenos Aires (Argentina)
Publication Date:
Research Org.:
Univ. of Siegen (Germany); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE; German Federal Ministry of Education and Research (BMBF); Helmholtz Alliance for Astroparticle Physics (HAP) (Germany)
OSTI Identifier:
1430011
Report Number(s):
LA-UR-17-29807
Journal ID: ISSN 0927-6505; TRN: US1802889
Grant/Contract Number:  
AC52-06NA25396
Resource Type:
Accepted Manuscript
Journal Name:
Astroparticle Physics
Additional Journal Information:
Journal Volume: 97; Journal ID: ISSN 0927-6505
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 79 ASTRONOMY AND ASTROPHYSICS; photons; cosmic rays; hybrid detector; lateral distribution function; LDF

Citation Formats

Niechciol, M., Risse, M., Ruehl, P., Settimo, M., Younk, P. W., and Yushkov, A. Fγ: A new observable for photon-hadron discrimination in hybrid air shower events. United States: N. p., 2017. Web. doi:10.1016/j.astropartphys.2017.10.004.
Niechciol, M., Risse, M., Ruehl, P., Settimo, M., Younk, P. W., & Yushkov, A. Fγ: A new observable for photon-hadron discrimination in hybrid air shower events. United States. https://doi.org/10.1016/j.astropartphys.2017.10.004
Niechciol, M., Risse, M., Ruehl, P., Settimo, M., Younk, P. W., and Yushkov, A. Sat . "Fγ: A new observable for photon-hadron discrimination in hybrid air shower events". United States. https://doi.org/10.1016/j.astropartphys.2017.10.004. https://www.osti.gov/servlets/purl/1430011.
@article{osti_1430011,
title = {Fγ: A new observable for photon-hadron discrimination in hybrid air shower events},
author = {Niechciol, M. and Risse, M. and Ruehl, P. and Settimo, M. and Younk, P. W. and Yushkov, A.},
abstractNote = {To search for ultra-high-energy photons in primary cosmic rays, air shower observables are needed that allow a good separation between primary photons and primary hadrons. In this paper, we present a new observable, Fγ, which can be extracted from ground-array data in hybrid events, where simultaneous measurements of the longitudinal and the lateral shower profile are performed. The observable is based on a template fit to the lateral distribution measured by the ground array with the template taking into account the complementary information from the measurement of the longitudinal profile, i.e. the primary energy and the geometry of the shower. Fγ shows a very good photon-hadron separation, which is even superior to the separation given by the well-known Xmax observable (the atmospheric depth of the shower maximum). At energies around 1 EeV (10 EeV), Fγ provides a background rejection better than 97.8 % (99.9 %) at a signal efficiency of 50 %. Advantages of the observable Fγ are its technical stability with respect to irregularities in the ground array (i.e. missing or temporarily non-operating stations) and that it can be applied over the full energy range accessible to the air shower detector, down to its threshold energy. Finally and furthermore, Fγ complements nicely to Xmax such that both observables can well be combined to achieve an even better discrimination power, exploiting the rich information available in hybrid events.},
doi = {10.1016/j.astropartphys.2017.10.004},
journal = {Astroparticle Physics},
number = ,
volume = 97,
place = {United States},
year = {2017},
month = {10}
}

Works referenced in this record:

Search for Ultra-High Energy Photons Using air Showers
journal, April 2007


Observation of the Suppression of the Flux of Cosmic Rays above 4 × 10 19 eV
journal, August 2008


A Targeted Search for Point Sources of EeV Photons with the Pierre Auger Observatory
journal, March 2017


Changes in extensive air showers from isotropic Lorentz violation in the photon sector
journal, October 2016


One-dimensional hybrid approach to extensive air shower simulation
journal, January 2007


First results of fast one-dimensional hybrid simulation of EAS using conex
journal, January 2006


EPOS LHC: Test of collective hadronization with data measured at the CERN Large Hadron Collider
journal, September 2015


Cosmic ray interaction event generator SIBYLL 2.1
journal, November 2009


Monte Carlo treatment of hadronic interactions in enhanced Pomeron scheme: QGSJET-II model
journal, January 2011


The surface detector array of the Telescope Array experiment
journal, October 2012

  • Abu-Zayyad, T.; Aida, R.; Allen, M.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 689
  • DOI: 10.1016/j.nima.2012.05.079

Upper limit on the cosmic-ray photon flux above 1019eV using the surface detector of the Pierre Auger Observatory
journal, May 2008


Upper limit on the flux of photons with energies above 10 19 eV using the Telescope Array surface detector
journal, December 2013


A new composition-sensitive parameter for ultra-high energy cosmic rays
journal, October 2011


Hybrid detection of ultra high energy cosmic rays with the Pierre Auger Observatory
journal, January 2010


A SEARCH FOR POINT SOURCES OF EeV PHOTONS
journal, June 2014


Improving photon-hadron discrimination based on cosmic ray surface detector data
journal, July 2013


The optimum distance at which to determine the size of a giant air shower
journal, January 2007


The FLUKA code: description and benchmarking
conference, January 2007

  • Battistoni, G.; Cerutti, F.; Fassò, A.
  • HADRONIC SHOWER SIMULATION WORKSHOP, AIP Conference Proceedings
  • DOI: 10.1063/1.2720455

The offline software framework of the Pierre Auger Observatory
journal, October 2007

  • Argirò, S.; Barroso, S. L. C.; Gonzalez, J.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 580, Issue 3
  • DOI: 10.1016/j.nima.2007.07.010

Reinterpreting the development of extensive air showers initiated by nuclei and photons
journal, July 2013

  • Domenico, Manlio De; Settimo, Mariangela; Riggi, Simone
  • Journal of Cosmology and Astroparticle Physics, Vol. 2013, Issue 07
  • DOI: 10.1088/1475-7516/2013/07/050

Bootstrap Methods: Another Look at the Jackknife
journal, January 1979


The use of Multiple Measurements in Taxonomic Problems
journal, September 1936


Radio detection of cosmic-ray air showers and high-energy neutrinos
journal, March 2017