Banerjee, D;
Burtsev, VE;
Chumakov, AG;
Cooke, D;
Crivelli, P;
Depero, E;
Dermenev, AV;
... Ulloa, P; + view all
(2018)
Search for a Hypothetical 16.7 MeV Gauge Boson and Dark Photons in the NA64 Experiment at CERN.
Physical Review Letters
, 120
(23)
, Article 231802. 10.1103/PhysRevLett.120.231802.
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Abstract
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 − Z X 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
| Type: | Article |
|---|---|
| Title: | Search for a Hypothetical 16.7 MeV Gauge Boson and Dark Photons in the NA64 Experiment at CERN |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1103/PhysRevLett.120.231802 |
| Publisher version: | https://doi.org/10.1103/PhysRevLett.120.231802 |
| Language: | English |
| Additional information: | hed by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. https://creativecommons.org/licenses/by/4.0/ |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10077866 |
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