Optimal-observable analysis of possible new physics inB→D(*)τντ

Abstract

We study all possible observables in B → D ( * ) τ ντ with new physics (NP), including new vector, scalar and tensor interactions, and investigate the prospects of extracting NP Wilson coefficients with optimal observables. Analysis of the full q 2 integrated branching fractions of B → D ( * ) τ ντ show that the overall sensitivity of the observables of B → Dτ ντ is more towards the scalar current, whereas the bin-by-bin analysis of q 2 distribution of the differential branching fraction points to regions of q 2 sensitive to tensor interactions. Interestingly, the observables in B → D * τ ντ are more sensitive to tensor interactions, and bin-by-bin analysis of this mode shows the distinct regions of q 2 sensitive to vector or scalar interactions. In addition to that, the τ polarisation asymmetry is found to be more sensitive to NP compared to the other observables, in both decay modes.

Probing new physics in B¯0→D(*)Ivanov1, Körner2, Tran3 2017Phys. Rev. D772680View full textAdd to dashboardCite

“…[44,46] that some correlations between P L and the decay rate are very useful for NP prediction. In addition, the NP couplings can be extracted from P L with much less uncertainties as compared to those from other observables [47].…”

“…The longitudinal polarization P L has also been used as a promising observable in order to probe NP inB 0 → D ( * ) τ −ν τ [39,[44][45][46][47][48]. P L has been found to be very sensitive to the scalar and tensor operators.…”

Looking for possible new physics in B→D(*)τντ in light of recent data

“…The most general effective Hamiltonian describing the b → c ν transitions (where = e, µ or τ ) with all possible four-fermion operators in the lowest dimension is given by [6],…”

“…The semitaunic decays B → D ( * ) τ ν τ have drawn a lot of attention in recent years as sensitive probes of NP [1][2][3][4][5][6]. The present experimental status is summarized in Fig.…”

B ¯ → D ∗ τ ν ¯ $$ \overline{B}\to {D}^{\left(\ast \right)}\tau \overline{\nu} $$ excesses in ALRSM constrained from B, D decays and D 0 − D ¯ 0 $$ {D}^0-{\overline{D}}^0 $$ mixing

“…Phenomenological studies of the four fermion operators that can explain the discrepancy have been addressed in refs. [14][15][16][17][18][19][20][21][22]. The excesses have been explained in a more generalized framework of 2HDM in refs.…”