Momentum Measurement of Charged Particles in FASER's Emulsion Detector at the LHC

/ Authors

Faser Collaboration Roshan Mammen Abraham, Xiaocong Ai, Saul Alonso Monsalve, John Anders, Emma Anderson, C. Antel, A. Ariga, Tomoko Ariga, Jeremy Atkinson, F. Bernlochner

and 124 more authors

Tobias Boeckh, Eliot Bornand, J. Boyd, L. Brenner, Angela Burger, Franck Cadoux, R. Cardella, D. Casper, Charlotte Cavanagh, Shiyang Chen, Xin Chen, Xing Cheng, Kohei Chinone, Dhruv Chouhan, Andrea Coccaro, Stephane D'ebieux, Ansh Desai, S. Dmitrievsky, R. Dobre, M. D’Onofrio, Sinead Eley, Yannick Favre, Jonathan L. Feng, C. Fenoglio, D. Ferrere, M. Fieg, Wissal Filali, E. Firu, Haruhi Fujimori, Edward Galantay, A. Garabaglu, S. Gibson, S. Gonzalez-Sevilla, Y. Gornushkin, Yotam Granov, Ji-Ming Gu, C. Gwilliam, E. Hammou, D. Hayakawa, M. Holzbock, Shih-Chieh Hsu, Zhen Hu, G. Iacobucci, T. Inada, L. Iodice, Sune Jakobsen, C. Jesús-Valls, A. Jofrehei, Hans Joos, E. Kajomovitz, T. Kanai, H. Kawahara, Alex Keyken, F. Kling, Daniela Kock, Pantelis Kontaxakis, Jelle Koorn, Umut Kose, Peter Krack, S. Kuehn, T. Kugathasan, Sebastian Laudage, L. Levinson, Botao Li, Jinfeng Liu, Yi Liu, M. Lutz, Jack MacDonald, J. Mahlstedt, Toni Makela, A. Mascellani, Lawson McCoy, J. Mcfayden, Andrea Pizarro Medina, T. Moretti, Keiko Moriyama, T. Nakano, L. Nevay, Motoya Nonaka, Yuma Ohara, Ken Ohashi, Kazuaki Okui, H. Otono, Lorenzo Paolozzi, Ann Parry, Pawan Pawan, B. Petersen, Titi Preda, M. Prim, Jun Qin, M. Queitsch-Maitland, Juan Rojo, H. Rokujo, A. Rubbia, Osamu Sato, P. Scampoli, Kristof Schmieden, Matthias Schott, Cristiano Sebastiani, Anna Sfyrla, D. Sgalaberna, M. Shamim, Y. Takubo, Noshin Tarannum, S. Thor, E. Torrence, Oscar Ivan Valdes Martinez, S. Vasina, B. Vormwald, Chi Wang, Yuxiao Wang, E. Brian Welch, Aaron White, M. Wielers, B. Wilson, Yue Xu, Heng Yang, Le Yao, Daichi Yoshikawa, S. Zambito, Shunliang Zhang, Yuxuan Zhang, Xingyu Zhao, Zijian Zhao

/ Abstract

We present a momentum measurement method based on multiple Coulomb scattering (MCS) in the FASER$\nu$ emulsion detector. The measurement of charged-particle momenta is essential for studying neutrino interactions in the TeV energy range at the FASER experiment. This method exploits the sub-micron spatial resolution and long tracking length of the FASER$\nu$ detector, enabling momentum determination from a few GeV up to a few TeV. The performance was evaluated using Geant4-based Monte Carlo simulations and validated with muon test beam data in the momentum range 100-300 GeV. As a first probe of the method for higher momentum muons, background muons recorded by the FASER$\nu$ detector were examined, showing reconstructed momenta consistent with expectations from their angular spread.