학술논문
Measurement of the intrinsic hadronic contamination in the NA64$-e$ high-purity $e^+/e^-$ beam at CERN
Document Type
Working Paper
Author
Andreev, Yu. M.; Banerjee, D.; Oberhauser, B. Banto; Bernhard, J.; Bisio, P.; Bondi, M.; Celentano, A.; Charitonidis, N.; Chumakov, A. G.; Cooke, D.; Crivelli, P.; Depero, E.; Dermenev, A. V.; Donskov, S. V.; Dusaev, R. R.; Enik, T.; Frolov, V. N.; Gardikiotis, A.; Gerassimov, S. G.; Gninenko, S. N.; H"osgen, M.; Jeckel, M.; Kachanov, V. A.; Kambar, Y.; Karneyeu, A. E.; Kekelidze, G.; Ketzer, B.; Kirpichnikov, D. V.; Kirsanov, M. M.; Kolosov, V. N.; Konorov, I. V.; Gertsenberger, S. V.; Kasianova, E. A.; Kovalenko, S. G.; Kramarenko, V. A.; Kravchuk, L. V.; Krasnikov, N. V.; Kuleshov, S. V.; Lyubovitskij, V. E.; Lysan, V.; Marini, A.; Marsicano, L.; Matveev, V. A.; Mikhailov, Yu. V.; Bueno, L. Molina; Mongillo, M.; Peshekhonov, D. V.; Polyakov, V. A.; Radics, B.; Rojas, R.; Salamatin, K.; Samoylenko, V. D.; Sieber, H.; Shchukin, D.; Soto, O.; Tikhomirov, V. O.; Tlisova, I.; Toropin, A. N.; Trifonov, A. Yu.; Tuzi, M.; Ulloa, P.; Vasilishin, B. I.; Arenas, G. Vasquez; Volkov, P. V.; Volkov, V. Yu.; Voronchikhin, I. V.; Zamora-Sa'a, J.; Zhevlakov, A. S.
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Subject
Language
Abstract
In this study, we present the measurement of the intrinsic hadronic contamination at the CERN SPS H4 beamline configured to transport electrons and positrons at 100 GeV/c momentum. The analysis was performed using data collected by the NA64-$e$ experiment in 2022. Our study is based on calorimetric measurements, exploiting the different interaction mechanisms of electrons and hadrons in the NA64-ECAL and NA64-HCAL detectors. We determined the intrinsic hadronic contamination by comparing the results obtained using the nominal electron/positron beamline configuration with those obtained in a dedicated setup, in which only hadrons impinged on the detector. The significant differences in the experimental signatures of electrons and hadrons motivated our approach, resulting in a small and well-controlled systematic uncertainty for the measurement. Our study allowed us to precisely determine the intrinsic hadronic contamination, which represents a crucial parameter for the NA64 experiment in which the hadron contaminants may result in non-trivial backgrounds. Moreover, we performed dedicated Monte Carlo simulations for the hadron production induced by the primary T2 target. We found a good agreement between measurements and simulation results, confirming the validity of the applied methodology and our evaluation of the intrinsic hadronic contamination.