Optimization of the proton background rejection in the measurement of the electron flux at high energies with CALET on the International Space Station
Creators: name: Adriani, Oscar
name: Akaike, Yosui
name: Asano, Katsuaki
name: Aaoka, Yoichi
name: Berti, Eugenio
name: Bigongiari, Gabriele
name: Binns, Walter Robert
name: Bongi, Massimo
name: Brogi, Paolo
name: Bruno, Alessandro
name: Cannady, Nicholas
name: Castellini, Guide
name: Checchia, Caterina
name: Cherry, Walter Robert
name: Collazuol, Gianmaria
name: De Nolfo, Georgia A.
name: Ebisawa, Ken
name: Ficklin, Anthony W.
name: Fuke, Hideyuki
name: Gonzi, Sandro
name: Guzik, T. Gregory
name: Hams, Thomas
name: Hibino, Kinya
name: Ichimura, Masakatsu
name: Ioka, Kunihito
name: Ishizaki, Wataru
name: Israel, Martin H.
name: Kasahara, Katsumasa
name: Kataoka, Jun
name: Kataoka, Ryuho
name: Katayose, Yusaku
name: Kato, Chihiro
name: Kawanaka, Norita
name: Kawakubo, Yuta
name: Kobayashi, Kenko
name: Kohri, Kazunori
name: Krawczynski, Henric S.
name: Krizmanic, John F.
name: Maestro, Paolo
name: Marrocchesi, Pier Simone
name: Messineo, Alberto Maria
name: Mitchell, Jason W.
name: Miyake, Shoko
name: Moiseev, Alexander
name: Mori, Masaki
name: Mori, Nicola
name: Motz, Holger Martin
name: Munakata, Kazuoki
name: Nakahira, Satoshi
name: Nishimura, Jun
name: Okuno, Shoji
name: Ormes, Jonathan
name: Ozawa, Shunsuke
name: Pacini, Lorenzo
name: Pacini, Paolo
name: Rauch, Brian Flint
name: Ricciarini, Ricciarini
name: Sakai, Kazuhiro
name: Sakamoto, Takanori
name: Sasaki, Makoto
name: Shimizu, Yuki
name: Shiomi, Atsushi
name: Spillantini, Piero
name: Stolzi, Francesco
name: Sugita, Satoshi
name: Sulaj, Arta
name: Takita, Masato
name: Tamura, Tadahisa
name: Terasawa, Toshio
name: Torii, Shoji
name: Tsunesada, Yoshiki
name: Uchihori, Yukio
name: Vannuccini, Elena
name: Wefel, John P.
name: Yamaoka, Kazutaka
name: Yanagita, Shohei
name: Yoshida, Atsumasa
name: Yoshida, Kenji
name: Zober, Wolfgang V.
Publisher: name: Proceedings of Science
Year: 2023

description: 38th International Cosmic Ray Conference (ICRC2023), 26 July - 3 August, 2023, Nagoya, Japan
description: The Calorimetric Electron Telescope (CALET) is a cosmic-ray observatory operating since October 2015 onboard the International Space Station (ISS). The data processed since the beginning of the mission has made it possible to measure with high precision the inclusive flux of cosmic electrons and positrons (all-electron) in the multi-TeV region. The appearance of any structures in this energy region can potentially be connected to the presence of nearby astrophysical sources or dark matter. The CALET detector, consisting of a charge detector, an imaging calorimeter and a total absorption calorimeter has a total vertical thickness of about 30 radiation lengths. The construction characteristics of the instrument allow to obtain an energy resolution better than 2% for electrons and a proton rejection power of about 10⁵. However, the exploration of the multi-TeV region involves dealing with a limited statistical sample and a large proton background. As a consequence, a complex multivariate analysis based on variables connected to the shower development has been adopted. In this contribution, we summarize the results of a study conducted on different multivariate analysis techniques in order to optimize the proton rejection at high energies in the all-electron flux measurement. In particular, we discuss the features of the different methods, the tuning of their parameters and the overall strategy to increase the separation between electrons and protons, avoiding the phenomenon of overfitting.