TY - JOUR
T1 - Flavor gauge models below the Fermi scale
AU - Babu, K. S.
AU - Friedland, A.
AU - Machado, P. A.N.
AU - Mocioiu, I.
N1 - Funding Information:
We thank KITP Santa Barbara for hospitality and support (National Science Foundation under Grant No. PHY11-25915) during the “Present and Future Neutrino Physics” workshop, where this work was started. PM thanks the Oklahoma State University and SLAC for kind hospitality during the completion of this manuscript. We thank Lance Dixon, Sasha Khanov, Aneesh Manohar, Carlos Peña, Michael Peskin, and Renata Zukanovich Funchal for useful discussions. This work is supported by the U.S. Department of Energy Grants No. de-sc0010108 (KSB), DE-AC02-76SF00515 (AF) and de-sc0013699 (IM), and by the EU grants H2020-MSCA-ITN-2015/674896-Elusives (PM) and H2020-MSCA-2015-690575-InvisiblesPlus (PM). Fermilab is operated by the Fermi Research Alliance, LLC under contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Publisher Copyright:
© 2017, The Author(s).
PY - 2017/12/1
Y1 - 2017/12/1
N2 - 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− D¯ 0 mixing, atomic parity violation, and neutrino scattering and oscillations. For the new gauge coupling gX 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. The proposed framework provides interesting connections between neutrino oscillations, flavor and collider physics.
AB - 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− D¯ 0 mixing, atomic parity violation, and neutrino scattering and oscillations. For the new gauge coupling gX 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. The proposed framework provides interesting connections between neutrino oscillations, flavor and collider physics.
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U2 - 10.1007/JHEP12(2017)096
DO - 10.1007/JHEP12(2017)096
M3 - Article
AN - SCOPUS:85039419073
VL - 2017
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
SN - 1126-6708
IS - 12
M1 - 96
ER -