New physics in the kinematic distributions of B¯→D(*)τ−(→

Abstract

We investigate the experimentally-accessible kinematic distributions of theB → D ( * ) τ − (→ −ν ντ )ντ decays. Specifically, we study the decay rates as functions of the B → D ( * ) transferred squared momentum, the energy of the final charged lepton and the angle of its 3-momentum with respect to the 3-momentum of the recoiling D ( * ) . The angular distribution allows to introduce new observables, like a forward-backward asymmetry, which are complementary to the total rates. We present analytic formulas for the observable 3-fold 5-body differential decay rates, study the predictions in the Standard Model and investigate the effects in different new-physics scenarios that we characterize using an effective field theory framework.

Probing new physics in B¯0→D(*)Ivanov1, Körner2, Tran3 2017Phys. Rev. D752680View full textAdd to dashboardCite

“…4, we compare our form factors with the Alonso-Kobach-Camalich (AKC) form factors calculated in Ref. [54] where they have used theoretical input from the HQET, lattice calculations, and equation of motion (EOM) relations. We rewrite the AKC form factors in our notation using the relations between the two sets of form factors.…”

“…(25) Yet another method to analyze the longitudinal polarization of the τ − has been suggested in Ref. [54] where a forward-backward asymmetry is defined with respect to cos θ * , where θ * is the angle between the final charged lepton and the recoiling D ( * ) in the W − rest system.…”

On the importance of electroweak corrections for B anomalies

“…(2.19) with where 25) and 26) where I i (i = 1, 2, 3) are finite and renormalization scale independent quantities defined as…”

“…In our setup, R τ / W is given by 44) which has to be compared with the LEP measurements [71] R τ /µ W = 1.068(26) , R τ /e W = 1.062 (26) .…”

“…[16][17][18][19][20][21][22]. In the recent literature, many studies focused on the experimental signatures implied by the solution of these anomalies in specific scenarios, including kaon observables [23,24], kinematic distributions in B decays [25][26][27][28][29][30][31][32][33][34][35], the lifetime of the B − c meson [36], Υ and ψ leptonic decays [37], tau lepton searches [38,39] and dark matter [40,41].…”