Z -boson decays into Majorana or Dirac heavy neutrinos
| Autor: | André de Gouvêa, Boris Kayser, A. Blondel |
|---|---|
| Přispěvatelé: | Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP) |
| Rok vydání: | 2021 |
| Předmět: |
at rest
Particle physics angular distribution: asymmetry neutrino: polarization Physics::Instrumentation and Detectors Astrophysics::High Energy Astrophysical Phenomena media_common.quotation_subject FOS: Physical sciences electron positron: annihilation Computer Science::Digital Libraries 01 natural sciences 7. Clean energy Asymmetry High Energy Physics - Experiment High Energy Physics - Experiment (hep-ex) symbols.namesake High Energy Physics - Phenomenology (hep-ph) 0103 physical sciences [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] Nuclear Experiment 010306 general physics media_common Physics 010308 nuclear & particles physics Z0: decay Dirac (video compression format) High Energy Physics::Phenomenology Order (ring theory) Observable Fermion neutrino: heavy 3. Good health High Energy Physics - Phenomenology MAJORANA Dirac fermion kinematics [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph] symbols neutrino: Majorana High Energy Physics::Experiment Neutrino neutrino: Dirac |
| Zdroj: | Phys.Rev.D Phys.Rev.D, 2021, 104 (5), pp.055027. ⟨10.1103/PhysRevD.104.055027⟩ Physical Review |
| ISSN: | 2470-0029 2470-0010 |
| DOI: | 10.1103/physrevd.104.055027 |
| Popis: | We computed the kinematics of Z-boson decay into a heavy-light neutrino pair when the Z-boson is produced at rest in electron-positron collisions, including the subsequent decay of the heavy neutrino into a visible final state containing a charged-lepton. We concentrated on heavy-neutrino masses of order dozens of GeV and the issue of addressing the nature of the neutrinos - Dirac fermions or Majorana fermions. We find that while it is not possible to tell the nature of the heavy and light neutrinos on an event-by-event basis, the nature of the neutrinos can nonetheless be inferred given a large-enough sample of heavy-light neutrino pairs. We identify two observables sensitive to the nature of neutrinos. One is the forward-backward asymmetry of the daughter-charged-leptons. This asymmetry is exactly zero if the neutrinos are Majorana fermions and is non-zero (and opposite) for positively- and negatively-charged daughter-leptons if the neutrinos are Dirac fermions. The other observable is the polarization of the heavy neutrino, imprinted in the laboratory-frame energy distribution of the daughter-charged-leptons. Dirac neutrinos and antineutrinos produced in electron-positron collisions at the Z-pole are strongly polarized while Majorana neutrinos are at most as polarized as the $Z$-bosons. 12 pages, 7 figures, references added in v2, results and conclusions unchanged |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|