Neutrino mixing and R K anomaly in U(1) X models: a bottom-up approach

Abstract

We identify a class of U(1) X models which can explain the R K anomaly and the neutrino mixing pattern, by using a bottom-up approach. The different X-charges of lepton generations account for the lepton universality violation required to explain R K . In addition to the three right-handed neutrinos needed for the Type-I seesaw mechanism, these minimal models only introduce an additional doublet Higgs and a singlet scalar. While the former helps in reproducing the quark mixing structure, the latter gives masses to neutrinos and the new gauge boson Z . Our bottom-up approach determines the Xcharges of all particles using theoretical consistency and experimental constraints. We find the parameter space allowed by the constraints from neutral meson mixing, rare b → s decays and direct collider searches for Z . Such a Z may be observable at the ongoing run of the Large Hadron Collider with a few hundred fb −1 of integrated luminosity.

New physics in b→sμ+μ− : Distinguishing models through CAlok1, Bhattacharya2, Kumar3 et al. 2017Phys. Rev. D786860View full textAdd to dashboardCite

“…Numerous models of this type have been proposed, see Refs. [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54].…”

Minimal flavored U(1)′ for B -meson anomalies

“…Furthermore, we extend the Higgs sector by including extra Higgs doublet and three complex singlet scalars and obtain the predictive patterns of quark and lepton mass matrices that are consistent with experimental data. There are similar minimal U (1) models for explaining the B-meson anomalies and neutrino mass generation where there are three right-handed neutrinos, extra Higgs doublet and scalar singlet(s) beyond the SM [12,14].…”

“…As the SM predictions for R K or R K * are almost unity, if confirmed, the above anomalies would be a hint at new physics for lepton non-universal interactions [4][5][6][7], such as flavor-dependent Z [8][9][10][11][12][13][14][15][16] and its non-abelian extensions [17], leptoquarks [9,18,19], light mediators [20], extra charged fermions [21], etc. On the other hand, we may need more caution in interpreting the anomalies in the angular distributions of B-meson decays such as P 5 , because it is prone to hadronic power corrections [22].…”

U(1)B3−3L2

“…11 is shown by black dot-dashed line. Note that the authors of Allowed region in g vs m Z obtained from the simplified parameter benchmark choice made in Eqs(19)(20)(21)(22). See text for detailed explanation of the constraints as well as their color code description .…”