A leptoquark model to accommodate R K exp  < R K SM and R K ∗ exp < R K ∗

Abstract

Abstract:We show that a modification of the model with a low energy scalar leptoquark state carrying hypercharge Y = 7/6 allows to accommodate both R K < 1 and R K * < 1, through loop effects, consistent with recent observations made at LHCb. We describe details of the model, compute the relevant Wilson coefficient and, after discussing a number of constraints, we examine the phenomenological consequences of the model. The bounds on the lepton flavor violating decay rates, induced by this model, include B(Z → µτ ) O(10 −7 ), and B(B → Kµτ ) O(10 −9 ). We also comment on the interpretation of the bounds on the leptoquark mass obtained from the direct searches at LHC.

Updated Bs -mixing constraints on new physics models for b→sℓ+ℓLuzio1, Kirk2, Lenz3 2018Phys. Rev. D13171631View full textAdd to dashboardCite

“…5 The scalar-leptoquark model proposed in Ref. [101] is a notable exception. 6 Similar considerations apply to the vector leptoquarks U μ 1 ∼ ð3; 1; 2=3Þ and U μ 3 ∼ ð3; 3; 2=3Þ, which also provide a good fit for R K ðÃÞ .…”

Explaining the $$R_K$$ R K and $$R_{K^*}$$ R K ∗

“…While the deviations from the Standard Model (SM) in the individual ratios are only at the level of 2.2σ -2.5σ , the a e-mail: diptimoy.ghosh@weizmann.ac.il combined deviation (the exact number depends on how one combines the 3 results) is large enough to look for NP explanations. 1 For recent studies, see [4,[13][14][15][16][17][18][19].…”

Footprints of leptoquarks: from $$ R_{K^{(*)}} $$ R K ( ∗ ) to

“…However, it was found in a full-fledged model, matched onto the effective Lagrangian, that it is very difficult to accommodate within 1σ the large value of R D ( * ) [24]. On the other hand it seems that R K ( * ) can be explained by a number of leptoquarks which contribute to b → sμ + μ − transition either at the tree-level [22,[25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] or at the loop-level [40][41][42].…”