Massive neutrinos demand to ask whether they are Dirac or Majorana particles. Majorana neutrinos are an irrefutable proof of physics beyond the Standard Model. Neutrinoless double electron capture is not a process but a virtual Δ L = 2 mixing between a parent A Z atom and a daughter A ( Z − 2) excited atom with two electron holes. As a mixing between two neutral atoms and the observable signal in terms of emitted two-hole X-rays, the strategy, experimental signature and background are different from neutrinoless double beta decay. The mixing is resonantly enhanced for almost degeneracy and, under these conditions, there is no irreducible background from the standard two-neutrino channel. We reconstruct the natural time history of a nominally stable parent atom since its production either by nature or in the laboratory. After the time periods of atom oscillations and the decay of the short-lived daughter atom, at observable times the relevant “stationary” states are the mixed metastable long-lived state and the non-orthogonal short-lived excited state, as well as the ground state of the daughter atom. We find that they have a natural population inversion which is most appropriate for exploiting the bosonic nature of the observed atomic transitions radiation. Among different observables of the atom Majorana mixing, we include the enhanced rate of stimulated X-ray emission from the long-lived metastable state by a high-intensity X-ray beam: a gain factor of 100 can be envisaged at current XFEL facilities. On the other hand, the historical population of the daughter atom ground state can be probed by exciting it with a current pulsed optical laser, showing the characteristic absorption lines: the whole population can be excited in a shorter time than typical pulse duration.
{
"_oai": {
"updated": "2018-04-30T21:43:12Z",
"id": "oai:repo.scoap3.org:23499"
},
"authors": [
{
"raw_name": "Bernab\u00e9u, Jos\u00e9",
"affiliations": [
{
"country": "Spain",
"value": "0000 0001 2173 938X, Departament de F\u00edsica Te\u00f2rica and IFIC, Universitat de Val\u00e8ncia \u2014 CSIC, Calle Dr. Moliner 50, E-46100, Burjassot, Spain"
}
],
"surname": "Bernab\u00e9u",
"given_names": "Jos\u00e9",
"full_name": "Bernab\u00e9u, Jos\u00e9"
},
{
"surname": "Segarra",
"given_names": "Alejandro",
"raw_name": "Segarra, Alejandro",
"affiliations": [
{
"country": "Spain",
"value": "0000 0001 2173 938X, Departament de F\u00edsica Te\u00f2rica and IFIC, Universitat de Val\u00e8ncia \u2014 CSIC, Calle Dr. Moliner 50, E-46100, Burjassot, Spain"
}
],
"full_name": "Segarra, Alejandro",
"orcid": "0000-0002-4101-536X"
}
],
"titles": [
{
"source": "Springer/SISSA",
"title": "Stimulated transitions in resonant atom Majorana mixing"
}
],
"dois": [
{
"value": "10.1007/JHEP02(2018)017"
}
],
"publication_info": [
{
"page_start": "017",
"material": "article",
"journal_title": "Journal of High Energy Physics",
"year": 2018
}
],
"$schema": "http://repo.scoap3.org/schemas/hep.json",
"acquisition_source": {
"date": "2018-02-03T00:00:00",
"source": "Springer/SISSA",
"method": "scoap3",
"submission_number": "3e8ae16c4cbc11e8b67702163e01809a"
},
"page_nr": [
16
],
"license": [
{
"url": "http://creativecommons.org/licenses/by/4.0/",
"license": "CC-BY-4.0"
}
],
"copyright": [
{
"statement": "The Author(s)"
}
],
"control_number": "23499",
"record_creation_date": "2018-02-03T00:00:00",
"_files": [
{
"checksum": "md5:bf09f4d6fc2a71bf30eadf97c51e2f62",
"filetype": "xml",
"bucket": "67c9f602-e59e-4049-983f-864b436826d6",
"version_id": "6f2a9176-716c-4794-a0cd-dae6f8def412",
"key": "10.1007/JHEP02(2018)017.xml",
"size": 54177
},
{
"checksum": "md5:df8678b528fe5215e0d9a66948dec277",
"filetype": "pdf/a",
"bucket": "67c9f602-e59e-4049-983f-864b436826d6",
"version_id": "5acd68c6-603d-49ce-9a6b-d96828738461",
"key": "10.1007/JHEP02(2018)017_a.pdf",
"size": 447252
}
],
"arxiv_eprints": [
{
"categories": [
"hep-ph"
],
"value": "1706.08328"
}
],
"abstracts": [
{
"source": "Springer/SISSA",
"value": "Massive neutrinos demand to ask whether they are Dirac or Majorana particles. Majorana neutrinos are an irrefutable proof of physics beyond the Standard Model. Neutrinoless double electron capture is not a process but a virtual \u0394 L = 2 mixing between a parent A Z atom and a daughter A ( Z \u2212 2) excited atom with two electron holes. As a mixing between two neutral atoms and the observable signal in terms of emitted two-hole X-rays, the strategy, experimental signature and background are different from neutrinoless double beta decay. The mixing is resonantly enhanced for almost degeneracy and, under these conditions, there is no irreducible background from the standard two-neutrino channel. We reconstruct the natural time history of a nominally stable parent atom since its production either by nature or in the laboratory. After the time periods of atom oscillations and the decay of the short-lived daughter atom, at observable times the relevant \u201cstationary\u201d states are the mixed metastable long-lived state and the non-orthogonal short-lived excited state, as well as the ground state of the daughter atom. We find that they have a natural population inversion which is most appropriate for exploiting the bosonic nature of the observed atomic transitions radiation. Among different observables of the atom Majorana mixing, we include the enhanced rate of stimulated X-ray emission from the long-lived metastable state by a high-intensity X-ray beam: a gain factor of 100 can be envisaged at current XFEL facilities. On the other hand, the historical population of the daughter atom ground state can be probed by exciting it with a current pulsed optical laser, showing the characteristic absorption lines: the whole population can be excited in a shorter time than typical pulse duration."
}
],
"imprints": [
{
"date": "2018-02-02",
"publisher": "Springer/SISSA"
}
]
}