학술논문
Search for a light muon-philic $Z^\prime$ with the NA64-$e$ experiment at CERN
Document Type
Working Paper
Author
Andreev, Yu. M.; Banerjee, D.; Oberhauser, B. Banto; Bernhard, J.; Bisio, P.; Bondì, M.; Burtsev, V. E.; 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.; Hösgen, M.; Jeckel, M.; Kachanov, V. A.; Karneyeu, A. E.; Kekelidze, G.; Ketzer, B.; Kirpichnikov, D. V.; Kirsanov, M. M.; Kolosov, V. N.; Konorov, I. V.; Kovalenko, S. G.; Kramarenko, V. A.; Kravchuk, L. V.; Krasnikov, N. V.; Kuleshov, S. V.; Lyubovitskij, V. E.; Lysan, V.; Marsicano, L.; Matveev, V. A.; Mikhailov, Yu. V.; Bueno, L. Molina; Peshekhonov, D. V.; Polyakov, V. A.; Radics, B.; Rojas, R.; Rubbia, A.; Salamatin, K. M.; Samoylenko, V. D.; Sieber, H.; Shchukin, D.; Tikhomirov, V. O.; Tlisova, I.; Toropin, A. N.; Trifonov, A. Yu; Ulloa, P.; Vasilishin, B. I.; Arenas, G. Vasquez; Volkov, P. V.; Volkov, V. Yu.; Voronchikhin, I.
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Subject
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Abstract
The extension of Standard Model made by inclusion of additional $U(1)$ gauge $L_\mu-L_\tau$ symmetry can explain the difference between the measured and the predicted value of the muon magnetic moment and solve the tension in $B$ meson decays. This model predicts the existence of a new, light $Z^\prime$ vector boson, predominantly coupled to second and third generation leptons, whose interaction with electrons is due to a loop mechanism involving muons and taus. In this work, we present a rigorous evaluation of the upper limits in the $Z^\prime$ parameter space, obtained from the analysis of the data collected by the NA64-$e$ experiment at CERN SPS, that performed a search for light dark matter with $2.84\times10^{11}$ electrons impinging with 100 GeV on an active thick target. The resulting limits, despite being included in a region already investigated by neutrino experiments,touch the muon $g-2$ preferred band for values of the $Z^\prime$ mass of order of 1 MeV. The sensitivity projections for the future high-statistics NA64-$e$ runs demonstrate the power of the electrons/positron beam approach in this theoretical scenario.
Comment: 11 pages, 9 figures. This version was accepted for publication
Comment: 11 pages, 9 figures. This version was accepted for publication