skip to main content


Title: Flavor gauge models below the Fermi scale

The mass and weak interaction eigenstates for the quarks of the third generation are very well aligned, an empirical fact for which the Standard Model offers no explanation. We explore the possibility that this alignment is due to an additional gauge symmetry in the third generation. Specifically, we construct and analyze an explicit, renormalizable model with a gauge boson, $X$, corresponding to the $B-L$ symmetry of the third family. Having a relatively light (in the MeV to multi-GeV range), flavor-nonuniversal gauge boson results in a variety of constraints from different sources. By systematically analyzing 20 different constraints, we identify the most sensitive probes: kaon, $B^+$, $D^+$ and Upsilon decays, $$D-\bar{D}^0$$ mixing, atomic parity violation, and neutrino scattering and oscillations. For the new gauge coupling $$g_X$$ in the range $$(10^{-2} - 10^{-4})$$ the model is shown to be consistent with the data. Possible ways of testing the model in $b$ physics, top and $Z$ decays, direct collider production and neutrino oscillation experiments, where one can observe nonstandard matter effects, are outlined. The choice of leptons to carry the new force is ambiguous, resulting in additional phenomenological implications, such as non-universality in semileptonic bottom decays. In conclusion, the proposed framework provides interesting connections between neutrino oscillations, flavor and collider physics.
 [1] ; ORCiD logo [2] ; ORCiD logo [3] ;  [4]
  1. Oklahoma State Univ., Stillwater, OK (United States)
  2. Stanford Univ., Menlo Park, CA (United States). SLAC National Accelerator Lab.
  3. Univ. Autonoma de Madrid, Madrid (Spain); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  4. The Pennsylvania State Univ., University Park, PA (United States)
Publication Date:
Report Number(s):
OSU-HEP-17-02; SLAC-PUB-16542; IFT-UAM-CSIC-16-051; FTUAM-16-21; FERMILAB-PUB-17-005-T; NSF-KITP-17-060; arXiv:1705.01822
Journal ID: ISSN 1029-8479; 1598143
Grant/Contract Number:
AC02-07CH11359; AC02-76SF00515
Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2017; Journal Issue: 12; Journal ID: ISSN 1029-8479
Springer Berlin
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Beyond Standard Model; Gauge Symmetry; Kaon Physics; Neutrino Physics
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1417658