Event-by-Event Analysis for TeV Electron Candidates with CALET on the International Space Station
Creators: name: Cannady, Nicholas
name: Akaike, Yosui
name: Torii, Shoji
name: Adriani, Oscar
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 Wade
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: 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 deep electromagnetic calorimeter designed for the measurement of cosmic-ray electrons on the International Space Station. Deployed on the Exposed Facility of the Japanese Experiment Module since August 2015, it observes cosmic-ray electrons with energies up to above 10 TeV and hadrons up to PeV total energies. Above a few TeV, the decrease in the electron flux and increased contamination by protons in the boosted decision tree (BDT) selection introduce challenges to determination of the flux at the highest energies and the search for signatures of nearby accelerators. To address the proton contamination, we apply a dedicated event-by-event analysis to evaluate the likelihood of each candidate event being a real electron or a contaminating proton. In this work, we detail the implementation of the likelihood analysis based on physically motivated shower parameters in the CALET calorimeter. Large simulated electron and proton datasets tailored to the parameters of the observed candidate events are generated and studied to produce a likelihood parameter for the improved rejection of protons. The results are tied to the BDT selection in the flight data analysis and summarized for the currently identified candidate events. Finally, we discuss an expansion of this work presently under development to use BDTs trained specifically for each candidate to provide an additional figure of merit.