Z′models for the LHCb andg−2muon anomalies

Abstract

We revisit a class of Z 0 explanations of the anomalies found by the LHCb collaboration in B decays, and show that the scenario is tightly constrained by a combination of constraints: (i) LHC searches for dimuon resonances, (ii) perturbativity of the Z 0 couplings; (iii) the B s mass difference, and (iv) electroweak precision data. Solutions are found by suppressing the Z 0 coupling to electrons and to light quarks and/or by allowing for a Z 0 decay width into dark matter. We also present a simplified framework where a TeV-scale Z 0 gauge boson that couples to standard leptons as well as to new heavy vectorlike leptons, can simultaneously accommodate the LHCb anomalies and the muon g − 2 anomaly.

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].…”

Lepton-flavor universality violation in R K and R D ∗ $$ {R}_{D^{{}_{\left(\ast \right)}}} $$ from warped space

“…Previous analyses in the literature have considered various ad hoc extensions of the Standard Model suitable to accommodate the anomalies, in particular including new gauge bosons [25][26][27][28][29][30][31][32][33][34][35], leptoquarks [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] and general effective field theory frameworks [51][52][53][54][55]. 2 Anomalies in R K , and b → s processes, have also been addressed in Randall-Sundrum [56][57][58] and flat space [59] extra dimensional scenarios.…”

Anomaly-free models for flavour anomalies

“…A popular interpretation of this anomaly is that it is due to the exchange of a U(1) gauge boson Z with non-universal couplings to both quarks and leptons [15,[22][23][24]27,28,31,[33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52]. It is possible to take a purely phenomenological attitude to this possibility, and not (yet) concern oneself about the theoretical consistency of such a Z model.…”