학술논문
Search for a light muon-philic $Z'$ with the NA64-$e$ experiment at CERN
Document Type
Working Paper
Author
Andreev, Yu. M.; Antonov, A.; Banerjee, D.; Oberhauser, B. Banto; Bernhard, J.; Bisio, P.; Celentano, A.; Charitonidis, N.; Cooke, D.; Crivelli, P.; Depero, E.; Dermenev, A. V.; Donskov, S. V.; Dusaev, R. R.; Enik, T.; Frolov, V. N.; Gardikiotis, A.; Gninenko, S. N.; Hösgen, M.; Kachanov, V. A.; Kambar, Y.; Karneyeu, A. E.; Kekelidze, G.; Ketzer, B.; Kirpichnikov, D. V.; Kirsanov, M. M.; Kolosov, V. N.; Gertsenberger, S. V.; Girod, S.; Kasianova, E. A.; Kramarenko, V. A.; Kravchuk, L. V.; Krasnikov, N. V.; Kuleshov, S. V.; Lyubovitskij, V. E.; Lysan, V.; Marini, A.; Marsicano, L.; Matveev, V. A.; Fredes, R. Mena; Yanssen, R. Mena; Bueno, L. Molina; Mongillo, M.; Peshekhonov, D. V.; Polyakov, V. A.; Radics, B.; Salamatin, K.; Samoylenko, V. D.; Sieber, H.; Shchukin, D.; Soto, O.; Tikhomirov, V. O.; Tlisova, I.; Toropin, A. N.; Tuzi, M.; Ulloa, P.; Volkov, P. V.; Volkov, V. Yu.; Voronchikhin, I. V.; Zamora-Saá, J.; Zhevlako, A. S.
Source
Subject
Language
Abstract
The inclusion of an additional U(1) gauge $L_{\mu} - L_{\tau}$ symmetry would release the tension between the measured and the predicted value of the anomalous muon magnetic moment: this paradigm assumes the existence of a new, light $Z'$ vector boson, with dominant coupling to ${\mu}$ and ${\tau}$ and interacting with electrons via a loop mechanism. The $L_{\mu} - L_{\tau}$ model can also explain the Dark Matter relic abundance, by assuming that the $Z'$ boson acts as a "portal" to a new Dark Sector of particles in Nature, not charged under known interactions. In this work we present the results of the $Z'$ search performed by the NA64-$e$ experiment at CERN SPS, that collected $ \sim 9 \times 10^{11}$ 100-GeV electrons impinging on an active thick target. Despite the suppressed $Z'$ production yield with an electron beam, the limits sets by NA64-$e$ are competitive with other experimental searches, and partially exclude the $g-2$ preferred model parameter values for $Z'$ masses lighter than 2 MeV. This result proves the complementarity of this search with NA64-${\mu}$, the parallel effort of the NA64 collaboration with a muon beam.
Comment: 7 pages, 4 figures
Comment: 7 pages, 4 figures