We report the first results on a direct search for a new 16.7 MeV boson () which could explain the anomalous excess of pairs observed in the excited nucleus decays. Because of its coupling to electrons, the could be produced in the bremsstrahlung reaction by a 100 GeV beam incident on an active target in the NA64 experiment at the CERN Super Proton Synchrotron and observed through the subsequent decay into a pair. With electrons on target, no evidence for such decays was found, allowing us to set first limits on the coupling in the range excluding part of the allowed parameter space. We also set new bounds on the mixing strength of photons with dark photons () from nonobservation of the decay of the bremsstrahlung with a mass .
{
"_oai": {
"updated": "2022-03-04T11:07:30Z",
"id": "oai:repo.scoap3.org:40699",
"sets": [
"PRL"
]
},
"authors": [
{
"raw_name": "D. Banerjee",
"affiliations": [
{
"country": "USA",
"value": "University of Illinois at Urbana Champaign, Urbana, 61801-3080 Illinois, USA"
}
],
"surname": "Banerjee",
"given_names": "D.",
"full_name": "Banerjee, D."
},
{
"raw_name": "V.\u2009E. Burtsev",
"affiliations": [
{
"country": "Russia",
"value": "Tomsk State Pedagogical University, 634061 Tomsk, Russia"
}
],
"surname": "Burtsev",
"given_names": "V.\u2009E.",
"full_name": "Burtsev, V.\u2009E."
},
{
"raw_name": "A.\u2009G. Chumakov",
"affiliations": [
{
"country": "Russia",
"value": "Tomsk State Pedagogical University, 634061 Tomsk, Russia"
}
],
"surname": "Chumakov",
"given_names": "A.\u2009G.",
"full_name": "Chumakov, A.\u2009G."
},
{
"raw_name": "D. Cooke",
"affiliations": [
{
"country": "Switzerland",
"value": "ETH Z\u00fcrich, Institute for Particle Physics and Astrophysics, CH-8093 Z\u00fcrich, Switzerland"
}
],
"surname": "Cooke",
"given_names": "D.",
"full_name": "Cooke, D."
},
{
"raw_name": "P. Crivelli",
"affiliations": [
{
"country": "Switzerland",
"value": "ETH Z\u00fcrich, Institute for Particle Physics and Astrophysics, CH-8093 Z\u00fcrich, Switzerland"
}
],
"surname": "Crivelli",
"given_names": "P.",
"full_name": "Crivelli, P."
},
{
"raw_name": "E. Depero",
"affiliations": [
{
"country": "Switzerland",
"value": "ETH Z\u00fcrich, Institute for Particle Physics and Astrophysics, CH-8093 Z\u00fcrich, Switzerland"
}
],
"surname": "Depero",
"given_names": "E.",
"full_name": "Depero, E."
},
{
"raw_name": "A.\u2009V. Dermenev",
"affiliations": [
{
"country": "Russia",
"value": "Institute for Nuclear Research, 117312 Moscow, Russia"
}
],
"surname": "Dermenev",
"given_names": "A.\u2009V.",
"full_name": "Dermenev, A.\u2009V."
},
{
"raw_name": "S.\u2009V. Donskov",
"affiliations": [
{
"country": "Russia",
"value": "State Scientific Center of the Russian Federation Institute for High Energy Physics of National Research Center \u201cKurchatov Institute\u201d (IHEP), 142281 Protvino, Russia"
}
],
"surname": "Donskov",
"given_names": "S.\u2009V.",
"full_name": "Donskov, S.\u2009V."
},
{
"raw_name": "R.\u2009R. Dusaev",
"affiliations": [
{
"country": "Russia",
"value": "Tomsk State Pedagogical University, 634061 Tomsk, Russia"
}
],
"surname": "Dusaev",
"given_names": "R.\u2009R.",
"full_name": "Dusaev, R.\u2009R."
},
{
"raw_name": "T. Enik",
"affiliations": [
{
"country": "JINR",
"value": "Joint Institute for Nuclear Research, 141980 Dubna, Russia"
}
],
"surname": "Enik",
"given_names": "T.",
"full_name": "Enik, T."
},
{
"raw_name": "N. Charitonidis",
"affiliations": [
{
"country": "CERN",
"value": "CERN, European Organization for Nuclear Research, CH-1211 Geneva, Switzerland"
}
],
"surname": "Charitonidis",
"given_names": "N.",
"full_name": "Charitonidis, N."
},
{
"raw_name": "A. Feshchenko",
"affiliations": [
{
"country": "JINR",
"value": "Joint Institute for Nuclear Research, 141980 Dubna, Russia"
}
],
"surname": "Feshchenko",
"given_names": "A.",
"full_name": "Feshchenko, A."
},
{
"raw_name": "V.\u2009N. Frolov",
"affiliations": [
{
"country": "JINR",
"value": "Joint Institute for Nuclear Research, 141980 Dubna, Russia"
}
],
"surname": "Frolov",
"given_names": "V.\u2009N.",
"full_name": "Frolov, V.\u2009N."
},
{
"raw_name": "A. Gardikiotis",
"affiliations": [
{
"country": "Greece",
"value": "Physics Department, University of Patras, 265 04 Patras, Greece"
}
],
"surname": "Gardikiotis",
"given_names": "A.",
"full_name": "Gardikiotis, A."
},
{
"raw_name": "S.\u2009G. Gerassimov",
"affiliations": [
{
"country": "Russia",
"value": "P.N. Lebedev Physics Institute, 119 991 Moscow, Russia"
},
{
"country": "Germany",
"value": "Technische Universit\u00e4t M\u00fcnchen, Physik Department, 85748 Garching, Germany"
}
],
"surname": "Gerassimov",
"given_names": "S.\u2009G.",
"full_name": "Gerassimov, S.\u2009G."
},
{
"raw_name": "S.\u2009N. Gninenko",
"affiliations": [
{
"country": "Russia",
"value": "Institute for Nuclear Research, 117312 Moscow, Russia"
}
],
"surname": "Gninenko",
"given_names": "S.\u2009N.",
"full_name": "Gninenko, S.\u2009N."
},
{
"raw_name": "M. H\u00f6sgen",
"affiliations": [
{
"country": "Germany",
"value": "Universit\u00e4t Bonn, Helmholtz-Institut f\u00fcr Strahlen-und Kernphysik, 53115 Bonn, Germany"
}
],
"surname": "H\u00f6sgen",
"given_names": "M.",
"full_name": "H\u00f6sgen, M."
},
{
"raw_name": "M. Jeckel",
"affiliations": [
{
"country": "CERN",
"value": "CERN, European Organization for Nuclear Research, CH-1211 Geneva, Switzerland"
}
],
"surname": "Jeckel",
"given_names": "M.",
"full_name": "Jeckel, M."
},
{
"raw_name": "A.\u2009E. Karneyeu",
"affiliations": [
{
"country": "Russia",
"value": "Institute for Nuclear Research, 117312 Moscow, Russia"
}
],
"surname": "Karneyeu",
"given_names": "A.\u2009E.",
"full_name": "Karneyeu, A.\u2009E."
},
{
"raw_name": "G. Kekelidze",
"affiliations": [
{
"country": "JINR",
"value": "Joint Institute for Nuclear Research, 141980 Dubna, Russia"
}
],
"surname": "Kekelidze",
"given_names": "G.",
"full_name": "Kekelidze, G."
},
{
"raw_name": "B. Ketzer",
"affiliations": [
{
"country": "Germany",
"value": "Universit\u00e4t Bonn, Helmholtz-Institut f\u00fcr Strahlen-und Kernphysik, 53115 Bonn, Germany"
}
],
"surname": "Ketzer",
"given_names": "B.",
"full_name": "Ketzer, B."
},
{
"raw_name": "D.\u2009V. Kirpichnikov",
"affiliations": [
{
"country": "Russia",
"value": "Institute for Nuclear Research, 117312 Moscow, Russia"
}
],
"surname": "Kirpichnikov",
"given_names": "D.\u2009V.",
"full_name": "Kirpichnikov, D.\u2009V."
},
{
"raw_name": "M.\u2009M. Kirsanov",
"affiliations": [
{
"country": "Russia",
"value": "Institute for Nuclear Research, 117312 Moscow, Russia"
}
],
"surname": "Kirsanov",
"given_names": "M.\u2009M.",
"full_name": "Kirsanov, M.\u2009M."
},
{
"raw_name": "I.\u2009V. Konorov",
"affiliations": [
{
"country": "Russia",
"value": "P.N. Lebedev Physics Institute, 119 991 Moscow, Russia"
},
{
"country": "Germany",
"value": "Technische Universit\u00e4t M\u00fcnchen, Physik Department, 85748 Garching, Germany"
}
],
"surname": "Konorov",
"given_names": "I.\u2009V.",
"full_name": "Konorov, I.\u2009V."
},
{
"raw_name": "S.\u2009G. Kovalenko",
"affiliations": [
{
"country": "Chile",
"value": "Universidad T\u00e9cnica Federico Santa Mar\u00eda, 2390123 Valpara\u00edso, Chile"
}
],
"surname": "Kovalenko",
"given_names": "S.\u2009G.",
"full_name": "Kovalenko, S.\u2009G."
},
{
"raw_name": "V.\u2009A. Kramarenko",
"affiliations": [
{
"country": "JINR",
"value": "Joint Institute for Nuclear Research, 141980 Dubna, Russia"
},
{
"country": "Russia",
"value": "Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia"
}
],
"surname": "Kramarenko",
"given_names": "V.\u2009A.",
"full_name": "Kramarenko, V.\u2009A."
},
{
"raw_name": "L.\u2009V. Kravchuk",
"affiliations": [
{
"country": "Russia",
"value": "Institute for Nuclear Research, 117312 Moscow, Russia"
}
],
"surname": "Kravchuk",
"given_names": "L.\u2009V.",
"full_name": "Kravchuk, L.\u2009V."
},
{
"raw_name": "N.\u2009V. Krasnikov",
"affiliations": [
{
"country": "Russia",
"value": "Institute for Nuclear Research, 117312 Moscow, Russia"
}
],
"surname": "Krasnikov",
"given_names": "N.\u2009V.",
"full_name": "Krasnikov, N.\u2009V."
},
{
"raw_name": "S.\u2009V. Kuleshov",
"affiliations": [
{
"country": "Chile",
"value": "Universidad T\u00e9cnica Federico Santa Mar\u00eda, 2390123 Valpara\u00edso, Chile"
}
],
"surname": "Kuleshov",
"given_names": "S.\u2009V.",
"full_name": "Kuleshov, S.\u2009V."
},
{
"raw_name": "V.\u2009E. Lyubovitskij",
"affiliations": [
{
"country": "Russia",
"value": "Tomsk State Pedagogical University, 634061 Tomsk, Russia"
},
{
"country": "Chile",
"value": "Universidad T\u00e9cnica Federico Santa Mar\u00eda, 2390123 Valpara\u00edso, Chile"
}
],
"surname": "Lyubovitskij",
"given_names": "V.\u2009E.",
"full_name": "Lyubovitskij, V.\u2009E."
},
{
"raw_name": "V. Lysan",
"affiliations": [
{
"country": "JINR",
"value": "Joint Institute for Nuclear Research, 141980 Dubna, Russia"
}
],
"surname": "Lysan",
"given_names": "V.",
"full_name": "Lysan, V."
},
{
"raw_name": "V.\u2009A. Matveev",
"affiliations": [
{
"country": "JINR",
"value": "Joint Institute for Nuclear Research, 141980 Dubna, Russia"
}
],
"surname": "Matveev",
"given_names": "V.\u2009A.",
"full_name": "Matveev, V.\u2009A."
},
{
"raw_name": "Yu.\u2009V. Mikhailov",
"affiliations": [
{
"country": "Russia",
"value": "State Scientific Center of the Russian Federation Institute for High Energy Physics of National Research Center \u201cKurchatov Institute\u201d (IHEP), 142281 Protvino, Russia"
}
],
"surname": "Mikhailov",
"given_names": "Yu.\u2009V.",
"full_name": "Mikhailov, Yu.\u2009V."
},
{
"raw_name": "D.\u2009V. Peshekhonov",
"affiliations": [
{
"country": "JINR",
"value": "Joint Institute for Nuclear Research, 141980 Dubna, Russia"
}
],
"surname": "Peshekhonov",
"given_names": "D.\u2009V.",
"full_name": "Peshekhonov, D.\u2009V."
},
{
"raw_name": "V.\u2009A. Polyakov",
"affiliations": [
{
"country": "Russia",
"value": "State Scientific Center of the Russian Federation Institute for High Energy Physics of National Research Center \u201cKurchatov Institute\u201d (IHEP), 142281 Protvino, Russia"
}
],
"surname": "Polyakov",
"given_names": "V.\u2009A.",
"full_name": "Polyakov, V.\u2009A."
},
{
"raw_name": "B. Radics",
"affiliations": [
{
"country": "Switzerland",
"value": "ETH Z\u00fcrich, Institute for Particle Physics and Astrophysics, CH-8093 Z\u00fcrich, Switzerland"
}
],
"surname": "Radics",
"given_names": "B.",
"full_name": "Radics, B."
},
{
"raw_name": "R. Rojas",
"affiliations": [
{
"country": "Chile",
"value": "Universidad T\u00e9cnica Federico Santa Mar\u00eda, 2390123 Valpara\u00edso, Chile"
}
],
"surname": "Rojas",
"given_names": "R.",
"full_name": "Rojas, R."
},
{
"raw_name": "A. Rubbia",
"affiliations": [
{
"country": "Switzerland",
"value": "ETH Z\u00fcrich, Institute for Particle Physics and Astrophysics, CH-8093 Z\u00fcrich, Switzerland"
}
],
"surname": "Rubbia",
"given_names": "A.",
"full_name": "Rubbia, A."
},
{
"raw_name": "V.\u2009D. Samoylenko",
"affiliations": [
{
"country": "Russia",
"value": "State Scientific Center of the Russian Federation Institute for High Energy Physics of National Research Center \u201cKurchatov Institute\u201d (IHEP), 142281 Protvino, Russia"
}
],
"surname": "Samoylenko",
"given_names": "V.\u2009D.",
"full_name": "Samoylenko, V.\u2009D."
},
{
"raw_name": "V.\u2009O. Tikhomirov",
"affiliations": [
{
"country": "Russia",
"value": "P.N. Lebedev Physics Institute, 119 991 Moscow, Russia"
}
],
"surname": "Tikhomirov",
"given_names": "V.\u2009O.",
"full_name": "Tikhomirov, V.\u2009O."
},
{
"raw_name": "D.\u2009A. Tlisov",
"affiliations": [
{
"country": "Russia",
"value": "Institute for Nuclear Research, 117312 Moscow, Russia"
}
],
"surname": "Tlisov",
"given_names": "D.\u2009A.",
"full_name": "Tlisov, D.\u2009A."
},
{
"raw_name": "A.\u2009N. Toropin",
"affiliations": [
{
"country": "Russia",
"value": "Institute for Nuclear Research, 117312 Moscow, Russia"
}
],
"surname": "Toropin",
"given_names": "A.\u2009N.",
"full_name": "Toropin, A.\u2009N."
},
{
"raw_name": "A.\u2009Yu. Trifonov",
"affiliations": [
{
"country": "Russia",
"value": "Tomsk State Pedagogical University, 634061 Tomsk, Russia"
}
],
"surname": "Trifonov",
"given_names": "A.\u2009Yu.",
"full_name": "Trifonov, A.\u2009Yu."
},
{
"raw_name": "B.\u2009I. Vasilishin",
"affiliations": [
{
"country": "Russia",
"value": "Tomsk State Pedagogical University, 634061 Tomsk, Russia"
}
],
"surname": "Vasilishin",
"given_names": "B.\u2009I.",
"full_name": "Vasilishin, B.\u2009I."
},
{
"raw_name": "G. Vasquez Arenas",
"affiliations": [
{
"country": "Chile",
"value": "Universidad T\u00e9cnica Federico Santa Mar\u00eda, 2390123 Valpara\u00edso, Chile"
}
],
"surname": "Vasquez Arenas",
"given_names": "G.",
"full_name": "Vasquez Arenas, G."
},
{
"raw_name": "P.\u2009V. Volkov",
"affiliations": [
{
"country": "JINR",
"value": "Joint Institute for Nuclear Research, 141980 Dubna, Russia"
},
{
"country": "Russia",
"value": "Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia"
}
],
"surname": "Volkov",
"given_names": "P.\u2009V.",
"full_name": "Volkov, P.\u2009V."
},
{
"raw_name": "V. Volkov",
"affiliations": [
{
"country": "Russia",
"value": "Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia"
}
],
"surname": "Volkov",
"given_names": "V.",
"full_name": "Volkov, V."
},
{
"raw_name": "P. Ulloa",
"affiliations": [
{
"country": "Chile",
"value": "Universidad T\u00e9cnica Federico Santa Mar\u00eda, 2390123 Valpara\u00edso, Chile"
}
],
"surname": "Ulloa",
"given_names": "P.",
"full_name": "Ulloa, P."
}
],
"titles": [
{
"source": "APS",
"title": "Search for a Hypothetical 16.7 MeV Gauge Boson and Dark Photons in the NA64 Experiment at CERN"
}
],
"dois": [
{
"value": "10.1103/PhysRevLett.120.231802"
}
],
"publication_info": [
{
"journal_volume": "120",
"journal_title": "Physical Review Letters",
"material": "article",
"journal_issue": "23",
"year": 2018
}
],
"$schema": "http://repo.scoap3.org/schemas/hep.json",
"acquisition_source": {
"date": "2020-06-29T15:25:42.162573",
"source": "APS",
"method": "APS",
"submission_number": "bca49440b8c511eaad8602163e01809a"
},
"page_nr": [
6
],
"license": [
{
"url": "https://creativecommons.org/licenses/by/4.0/",
"license": "CC-BY-4.0"
}
],
"copyright": [
{
"statement": "Published by the American Physical Society",
"year": "2018"
}
],
"control_number": "40699",
"collaborations": [
{
"value": "NA64 Collaboration"
}
],
"_files": [
{
"checksum": "md5:9190e5d7336af7508e10e427324c88b4",
"filetype": "pdf",
"bucket": "756e9b7e-deb9-4190-a94d-db5ae78a7357",
"version_id": "f3193c01-2101-4aa9-8d24-2c81009dc41e",
"key": "10.1103/PhysRevLett.120.231802.pdf",
"size": 300272
},
{
"checksum": "md5:0d737589da59ed7f3129e2d2ca07d880",
"filetype": "xml",
"bucket": "756e9b7e-deb9-4190-a94d-db5ae78a7357",
"version_id": "6ceffda8-2dd0-4a52-b516-3b7cde772761",
"key": "10.1103/PhysRevLett.120.231802.xml",
"size": 121072
}
],
"record_creation_date": "2018-07-06T09:00:27.853894",
"collections": [
{
"primary": "HEP"
},
{
"primary": "Citeable"
},
{
"primary": "Published"
}
],
"arxiv_eprints": [
{
"categories": [
"hep-ex",
"hep-ph"
],
"value": "1803.07748"
}
],
"abstracts": [
{
"source": "APS",
"value": "We report the first results on a direct search for a new 16.7 MeV boson (<math><mi>X</mi></math>) which could explain the anomalous excess of <math><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>\u2212</mo></msup></math> pairs observed in the excited <math><mrow><mmultiscripts><mrow><msup><mrow><mi>Be</mi></mrow><mrow><mo>*</mo></mrow></msup></mrow><mprescripts></mprescripts><none></none><mrow><mn>8</mn></mrow></mmultiscripts></mrow></math> nucleus decays. Because of its coupling to electrons, the <math><mi>X</mi></math> could be produced in the bremsstrahlung reaction <math><msup><mi>e</mi><mo>\u2212</mo></msup><mi>Z</mi><mo>\u2192</mo><msup><mi>e</mi><mo>\u2212</mo></msup><mi>Z</mi><mi>X</mi></math> by a 100 GeV <math><msup><mi>e</mi><mo>\u2212</mo></msup></math> beam incident on an active target in the NA64 experiment at the CERN Super Proton Synchrotron and observed through the subsequent decay into a <math><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>\u2212</mo></msup></math> pair. With <math><mn>5.4</mn><mo>\u00d7</mo><msup><mn>10</mn><mn>10</mn></msup></math> electrons on target, no evidence for such decays was found, allowing us to set first limits on the <math><mi>X</mi><mo>\u2212</mo><msup><mi>e</mi><mo>\u2212</mo></msup></math> coupling in the range <math><mrow><mn>1.3</mn><mo>\u00d7</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>\u2212</mo><mn>4</mn></mrow></msup><mo>\u2272</mo><msub><mrow><mi>\u03b5</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>\u2272</mo><mn>4.2</mn><mo>\u00d7</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>\u2212</mo><mn>4</mn></mrow></msup></mrow></math> excluding part of the allowed parameter space. We also set new bounds on the mixing strength of photons with dark photons (<math><msup><mi>A</mi><mo>\u2032</mo></msup></math>) from nonobservation of the decay <math><msup><mi>A</mi><mo>\u2032</mo></msup><mo>\u2192</mo><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>\u2212</mo></msup></math> of the bremsstrahlung <math><msup><mi>A</mi><mo>\u2032</mo></msup></math> with a mass <math><mo>\u2272</mo><mn>23</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>."
}
],
"imprints": [
{
"date": "2018-06-08",
"publisher": "APS"
}
]
}