Search for a Hypothetical 16.7 MeV Gauge Boson and Dark Photons in the NA64 Experiment at CERN; Physical Review Letters; Vol. 120, iss. 23
| Parent link: | Physical Review Letters Vol. 120, iss. 23.— 2018.— [231802, 6 p.] |
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| Autor Corporativo: | |
| Otros Autores: | , , , , , , , |
| Sumario: | Title screen 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 8Be∗ 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 5.4×1010 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≲εe≲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. |
| Lenguaje: | inglés |
| Publicado: |
2018
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| Materias: | |
| Acceso en línea: | http://earchive.tpu.ru/handle/11683/57547 https://doi.org/10.1103/PhysRevLett.120.231802 |
| Formato: | Electrónico Capítulo de libro |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=660109 |
| Sumario: | Title screen 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 8Be∗ 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 5.4×1010 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≲εe≲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. |
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| DOI: | 10.1103/PhysRevLett.120.231802 |