Heavy neutrino-antineutrino oscillations at the FCC-ee
Abstract We discuss the impact of heavy neutrino-antineutrino oscillations ( N N ¯ Os $$ \textrm{N}\overline{\textrm{N}}\textrm{Os} $$ ) on heavy neutral lepton (HNL) searches at proposed electron-positron colliders such as the future circular e + e − collider (FCC-ee). During the Z pole run, HNLs c...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2023-10-01
|
| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/JHEP10(2023)129 |
| _version_ | 1827370607181824000 |
|---|---|
| author | Stefan Antusch Jan Hajer Bruno M. S. Oliveira |
| author_facet | Stefan Antusch Jan Hajer Bruno M. S. Oliveira |
| author_sort | Stefan Antusch |
| collection | DOAJ |
| description | Abstract We discuss the impact of heavy neutrino-antineutrino oscillations ( N N ¯ Os $$ \textrm{N}\overline{\textrm{N}}\textrm{Os} $$ ) on heavy neutral lepton (HNL) searches at proposed electron-positron colliders such as the future circular e + e − collider (FCC-ee). During the Z pole run, HNLs can be produced alongside a light neutrino or antineutrino that escapes detection and can decay into a charged lepton or antilepton together with an off-shell W boson. In this case, signals of lepton number violation (LNV) only show up in the final state distributions. We discuss how N N ¯ Os $$ \textrm{N}\overline{\textrm{N}}\textrm{Os} $$ , a typical feature of collider-testable low-scale seesaw models where the heavy neutrinos form pseudo-Dirac pairs, modify such final state distributions. For example, the forward-backward asymmetry (FBA) of the reconstructed heavy (anti)neutrinos develops an oscillatory dependence on the HNL lifetime. We show that these oscillations can be resolvable for long-lived HNLs. We also discuss that when the N N ¯ Os $$ \textrm{N}\overline{\textrm{N}}\textrm{Os} $$ are not resolvable, they can nevertheless significantly modify the theory predictions for FBAs and observables such as the ratio of the total number of HNL decays into ℓ − over ones into ℓ +, in an interval of the angle θ between the HNL and the beam axis. Our results show that N N ¯ Os $$ \textrm{N}\overline{\textrm{N}}\textrm{Os} $$ should be included in collider simulations of HNLs at the FCC-ee. |
| first_indexed | 2024-03-08T10:17:59Z |
| format | Article |
| id | doaj.art-ad0e33d0ec2e4de497cb795e44d8efce |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-03-08T10:17:59Z |
| publishDate | 2023-10-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-ad0e33d0ec2e4de497cb795e44d8efce2024-01-28T12:20:49ZengSpringerOpenJournal of High Energy Physics1029-84792023-10-0120231011510.1007/JHEP10(2023)129Heavy neutrino-antineutrino oscillations at the FCC-eeStefan Antusch0Jan Hajer1Bruno M. S. Oliveira2Departement Physik, Universität BaselCentro de Física Teórica de Partículas (CFTP), Instituto Superior Técnico (IST), Universidade de LisboaDepartamento de Física, Instituto Superior Técnico (IST), Universidade de LisboaAbstract We discuss the impact of heavy neutrino-antineutrino oscillations ( N N ¯ Os $$ \textrm{N}\overline{\textrm{N}}\textrm{Os} $$ ) on heavy neutral lepton (HNL) searches at proposed electron-positron colliders such as the future circular e + e − collider (FCC-ee). During the Z pole run, HNLs can be produced alongside a light neutrino or antineutrino that escapes detection and can decay into a charged lepton or antilepton together with an off-shell W boson. In this case, signals of lepton number violation (LNV) only show up in the final state distributions. We discuss how N N ¯ Os $$ \textrm{N}\overline{\textrm{N}}\textrm{Os} $$ , a typical feature of collider-testable low-scale seesaw models where the heavy neutrinos form pseudo-Dirac pairs, modify such final state distributions. For example, the forward-backward asymmetry (FBA) of the reconstructed heavy (anti)neutrinos develops an oscillatory dependence on the HNL lifetime. We show that these oscillations can be resolvable for long-lived HNLs. We also discuss that when the N N ¯ Os $$ \textrm{N}\overline{\textrm{N}}\textrm{Os} $$ are not resolvable, they can nevertheless significantly modify the theory predictions for FBAs and observables such as the ratio of the total number of HNL decays into ℓ − over ones into ℓ +, in an interval of the angle θ between the HNL and the beam axis. Our results show that N N ¯ Os $$ \textrm{N}\overline{\textrm{N}}\textrm{Os} $$ should be included in collider simulations of HNLs at the FCC-ee.https://doi.org/10.1007/JHEP10(2023)129Baryon/Lepton Number ViolationSpecific BSM Phenomenology |
| spellingShingle | Stefan Antusch Jan Hajer Bruno M. S. Oliveira Heavy neutrino-antineutrino oscillations at the FCC-ee Journal of High Energy Physics Baryon/Lepton Number Violation Specific BSM Phenomenology |
| title | Heavy neutrino-antineutrino oscillations at the FCC-ee |
| title_full | Heavy neutrino-antineutrino oscillations at the FCC-ee |
| title_fullStr | Heavy neutrino-antineutrino oscillations at the FCC-ee |
| title_full_unstemmed | Heavy neutrino-antineutrino oscillations at the FCC-ee |
| title_short | Heavy neutrino-antineutrino oscillations at the FCC-ee |
| title_sort | heavy neutrino antineutrino oscillations at the fcc ee |
| topic | Baryon/Lepton Number Violation Specific BSM Phenomenology |
| url | https://doi.org/10.1007/JHEP10(2023)129 |
| work_keys_str_mv | AT stefanantusch heavyneutrinoantineutrinooscillationsatthefccee AT janhajer heavyneutrinoantineutrinooscillationsatthefccee AT brunomsoliveira heavyneutrinoantineutrinooscillationsatthefccee |