Search for a Hypothetical 16.7 MeV Gauge Boson and Dark Photons in the NA64 Experiment at CERN.

Autor: Banerjee D; University of Illinois at Urbana Champaign, Urbana, 61801-3080 Illinois, USA., Burtsev VE; Tomsk State Pedagogical University, 634061 Tomsk, Russia., Chumakov AG; Tomsk State Pedagogical University, 634061 Tomsk, Russia., Cooke D; ETH Zürich, Institute for Particle Physics and Astrophysics, CH-8093 Zürich, Switzerland., Crivelli P; ETH Zürich, Institute for Particle Physics and Astrophysics, CH-8093 Zürich, Switzerland., Depero E; ETH Zürich, Institute for Particle Physics and Astrophysics, CH-8093 Zürich, Switzerland., Dermenev AV; Institute for Nuclear Research, 117312 Moscow, Russia., Donskov SV; State Scientific Center of the Russian Federation Institute for High Energy Physics of National Research Center 'Kurchatov Institute' (IHEP), 142281 Protvino, Russia., Dusaev RR; Tomsk State Pedagogical University, 634061 Tomsk, Russia., Enik T; Joint Institute for Nuclear Research, 141980 Dubna, Russia., Charitonidis N; CERN, European Organization for Nuclear Research, CH-1211 Geneva, Switzerland., Feshchenko A; Joint Institute for Nuclear Research, 141980 Dubna, Russia., Frolov VN; Joint Institute for Nuclear Research, 141980 Dubna, Russia., Gardikiotis A; Physics Department, University of Patras, 265 04 Patras, Greece., Gerassimov SG; P.N. Lebedev Physics Institute, 119 991 Moscow, Russia.; Technische Universität München, Physik Department, 85748 Garching, Germany., Gninenko SN; Institute for Nuclear Research, 117312 Moscow, Russia., Hösgen M; Universität Bonn, Helmholtz-Institut für Strahlen-und Kernphysik, 53115 Bonn, Germany., Jeckel M; CERN, European Organization for Nuclear Research, CH-1211 Geneva, Switzerland., Karneyeu AE; Institute for Nuclear Research, 117312 Moscow, Russia., Kekelidze G; Joint Institute for Nuclear Research, 141980 Dubna, Russia., Ketzer B; Universität Bonn, Helmholtz-Institut für Strahlen-und Kernphysik, 53115 Bonn, Germany., Kirpichnikov DV; Institute for Nuclear Research, 117312 Moscow, Russia., Kirsanov MM; Institute for Nuclear Research, 117312 Moscow, Russia., Konorov IV; P.N. Lebedev Physics Institute, 119 991 Moscow, Russia.; Technische Universität München, Physik Department, 85748 Garching, Germany., Kovalenko SG; Universidad Técnica Federico Santa María, 2390123 Valparaíso, Chile., Kramarenko VA; Joint Institute for Nuclear Research, 141980 Dubna, Russia.; Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia., Kravchuk LV; Institute for Nuclear Research, 117312 Moscow, Russia., Krasnikov NV; Institute for Nuclear Research, 117312 Moscow, Russia., Kuleshov SV; Universidad Técnica Federico Santa María, 2390123 Valparaíso, Chile., Lyubovitskij VE; Tomsk State Pedagogical University, 634061 Tomsk, Russia.; Universidad Técnica Federico Santa María, 2390123 Valparaíso, Chile., Lysan V; Joint Institute for Nuclear Research, 141980 Dubna, Russia., Matveev VA; Joint Institute for Nuclear Research, 141980 Dubna, Russia., Mikhailov YV; State Scientific Center of the Russian Federation Institute for High Energy Physics of National Research Center 'Kurchatov Institute' (IHEP), 142281 Protvino, Russia., Peshekhonov DV; Joint Institute for Nuclear Research, 141980 Dubna, Russia., Polyakov VA; State Scientific Center of the Russian Federation Institute for High Energy Physics of National Research Center 'Kurchatov Institute' (IHEP), 142281 Protvino, Russia., Radics B; ETH Zürich, Institute for Particle Physics and Astrophysics, CH-8093 Zürich, Switzerland., Rojas R; Universidad Técnica Federico Santa María, 2390123 Valparaíso, Chile., Rubbia A; ETH Zürich, Institute for Particle Physics and Astrophysics, CH-8093 Zürich, Switzerland., Samoylenko VD; State Scientific Center of the Russian Federation Institute for High Energy Physics of National Research Center 'Kurchatov Institute' (IHEP), 142281 Protvino, Russia., Tikhomirov VO; P.N. Lebedev Physics Institute, 119 991 Moscow, Russia., Tlisov DA; Institute for Nuclear Research, 117312 Moscow, Russia., Toropin AN; Institute for Nuclear Research, 117312 Moscow, Russia., Trifonov AY; Tomsk State Pedagogical University, 634061 Tomsk, Russia., Vasilishin BI; Tomsk State Pedagogical University, 634061 Tomsk, Russia., Vasquez Arenas G; Universidad Técnica Federico Santa María, 2390123 Valparaíso, Chile., Volkov PV; Joint Institute for Nuclear Research, 141980 Dubna, Russia.; Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia., Volkov V; Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia., Ulloa P; Universidad Técnica Federico Santa María, 2390123 Valparaíso, Chile.
Jazyk: angličtina
Zdroj: Physical review letters [Phys Rev Lett] 2018 Jun 08; Vol. 120 (23), pp. 231802.
DOI: 10.1103/PhysRevLett.120.231802
Abstrakt: We report the first results on a direct search for a new 16.7 MeV boson (X) which could explain the anomalous excess of e^{+}e^{-} pairs observed in the excited ^{8}Be^{*} nucleus decays. Because of its coupling to electrons, the X could be produced in the bremsstrahlung reaction e^{-}Z→e^{-}ZX by a 100 GeV e^{-} beam incident on an active target in the NA64 experiment at the CERN Super Proton Synchrotron and observed through the subsequent decay into a e^{+}e^{-} pair. With 5.4×10^{10} electrons on target, no evidence for such decays was found, allowing us to set first limits on the X-e^{-} coupling in the range 1.3×10^{-4}≲ε_{e}≲4.2×10^{-4} excluding part of the allowed parameter space. We also set new bounds on the mixing strength of photons with dark photons (A^{'}) from nonobservation of the decay A^{'}→e^{+}e^{-} of the bremsstrahlung A^{'} with a mass ≲23  MeV.
Databáze: MEDLINE
Externí odkaz: