1. Search for a light $Z′$ in the $L_μ-L_τ$ scenario with the NA64-$e$ experiment at CERN
- Author
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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., Samalantin, K., 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., and Voronchikhin, I.
- Subjects
hep-ex ,High Energy Physics::Experiment ,hep-ph ,Particle Physics - Experiment ,Particle Physics - Phenomenology - Abstract
The extension of Standard Model made by inclusion of additional U(1) gauge Lμ-Lτ 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′ 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′ 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 2.84×1011 electrons impinging with 100 GeV on an active thick target. The resulting limits touch the muon g-2 preferred band for values of the Z′ mass of order of 1 MeV, while the sensitivity projections for the future high-statistics NA64-e runs demonstrate the power of the electrons/positron beam approach in this theoretical scenario. 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.
- Published
- 2022