Marriage between neutrino mass and flavor anomalies

Abstract

Experimental hints for lepton flavor universality violation in beauty-quark decay both in neutraland charged-current transitions require an extension of the Standard Model for which scalar leptoquarks (LQs) are the prime candidates. Besides, these same LQs can resolve the long-standing tension in the muon and the recently reported deviation in the electron g − 2 anomalies. These tantalizing flavor anomalies have discrepancies in the range of 2.5σ − 4.2σ, indicating that the Standard Model of particle physics may finally be cracking. In this Letter, we propose a resolution to all these anomalies within a unified framework that sheds light on the origin of neutrino mass. In this model, the LQs that address flavor anomalies run through the loops and generate neutrino mass at the two-loop order while satisfying all constraints from collider searches, including those from flavor physics.

Leptoquark-vectorlike quark model for the CDF $m_W$, $(g-2)_μ$, $R_{K^{(\ast)}}$ anomalies and neutrino mass

“…( 26) cannot be accommodated. To generate viable neutrino masses and mixings, a few more entries must be introduced in y S , which would lead to both charged lepton flavor violation as well as flavor violations in the quark sector [144][145][146] (see also [129,[147][148][149][150][151][152][153][154][155][156]).…”

Scotogenic Dirac neutrino mass models embedded with leptoquarks: one pathway to address the flavor anomalies and the neutrino masses together

“…It becomes clear that, besides the vector LQ options U 1 and V 2 , two more are available: (i) S 1 and S 3 , and (ii) R 2 and S 3 . Both options have been explored to address these flavor anomalies in a unified framework [80][81][82][83][84][85][86][87].…”

“…Namely, the absence of any particle accounting for the anomalies will fail to generate the neutrino masses (the same idea has been appreciated recently in Refs. [84,86]). In the mighty models consisting of the scalar LQs in Table III, on the other hand, such a connection is miss- ing, since removing S 1 or S 3 in the enlarged model A-1 (A-2) associated with, e.g., T1-i-a does not render the neutrino massless.…”

“…Besides the problems imposed by neutrinos and DM, several intriguing anomalies in the B-meson decays, particularly in the ratios R D ( * ) [60][61][62][63][64][65][66][67][68] and R K ( * ) [69][70][71][72][73][74], as well as in the muon g − 2 measurements [75,76] have been reported in recent years. Interestingly, it has been demonstrated that models with only a single leptoquark (LQ) [77][78][79] or a few of them [80][81][82][83][84][85][86][87] are capable of addressing all the flavor anomalies simultaneously. Inspired by the spirit of SDνM, we will explore if these "stones", once combined properly, can crack all the flavor anomalies, together with the origin of neutrino masses and the nature of dark matter in a unified picture.…”

Possibly heteroclite electron Yukawa coupling and small $\triangle a_μ$ in a hidden Abelian gauge model for neutrino masses

“…For recent attemps to explain both △a e,µ and neutrino mass generation, see for example, Refs. [25][26][27][28][29][30][31][32][33][34][35][36][37][38]. Although we focus on the flavor physics in this work, the potential connection to dark matter is another motivation for us to consider the hidden gauge U (1) X .…”