Test of new physics effects in $$ \overline{B}\to \left({D}^{\left(\ast \right)},\pi \right){\ell}^{-}{\overline{\nu}}_{\ell } $$ decays with heavy and light leptons

Abstract

A bstract We study the $$ \overline{B}\to D\left({D}^{\ast}\right){\ell}^{-}{\overline{\nu}}_{\ell } $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>B</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>→</mml:mo> <mml:mi>D</mml:mi> <mml:mfenced> <mml:msup> <mml:mi>D</mml:mi> <mml:mo>∗</mml:mo> </mml:msup> </mml:mfenced> <mml:msup> <mml:mi>ℓ</mml:mi> <mml:mo>−</mml:mo> </mml:msup> <mml:msub> <mml:mover> <mml:mi>ν</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>ℓ</mml:mi> </mml:msub> </mml:math> decays based on the up-to-date available inputs from experiments and the lattice. First, we review the standard model (SM) predictions of the different observables associated with these decay channels. In the analyses, we consider new physics (NP) effects in the channels with the heavy ( τ ), as well as the light leptons ( μ , e ). We have extracted | V cb | along with the new physics Wilson coefficients (WCs) from the available data on light leptons; the extracted value of | V cb | is (40 . 3 ± 0 . 5) × 10 − 3 . The extracted WCs are consistent with zero, but some could be of order 10 − 2 . Also, we have done the simultaneous analysis of the data in $$ \overline{B}\to {D}^{\left(\ast \right)}\left({\mu}^{-},{e}^{-}\right)\overline{\nu} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>B</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>D</mml:mi> <mml:mfenced> <mml:mo>∗</mml:mo> </mml:mfenced> </mml:msup> <mml:mfenced> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>−</mml:mo> </mml:msup> <mml:msup> <mml:mi>e</mml:mi> <mml:mo>−</mml:mo> </mml:msup> </mml:mfenced> <mml:mover> <mml:mi>ν</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> alongside the inputs on $$ R\left({D}^{\left(\ast \right)}\right)=\frac{\Gamma \left(\overline{B}\to {D}^{\left(\ast \right)}{\tau}^{-}{\overline{\nu}}_{\tau}\right)}{\Gamma \left(\overline{B}\to {D}^{\left(\ast \right)}{\ell}^{-}{\overline{\nu}}_{\ell}\right)} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>R</mml:mi> <mml:mfenced> <mml:msup> <mml:mi>D</mml:mi> <mml:mfenced> <mml:mo>∗</mml:mo> </mml:mfenced> </mml:msup> </mml:mfenced> <mml:mo>=</mml:mo> <mml:mfrac> <mml:mrow> <mml:mi>Γ</mml:mi> <mml:mfenced> <mml:mrow> <mml:mover> <mml:mi>B</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>D</mml:mi> <mml:mfenced> <mml:mo>∗</mml:mo> </mml:mfenced> </mml:msup> <mml:msup> <mml:mi>τ</mml:mi> <mml:mo>−</mml:mo> </mml:msup> <mml:msub> <mml:mover> <mml:mi>ν</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>τ</mml:mi> </mml:msub> </mml:mrow> </mml:mfenced> </mml:mrow> <mml:mrow> <mml:mi>Γ</mml:mi> <mml:mfenced> <mml:mrow> <mml:mover> <mml:mi>B</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>D</mml:mi> <mml:mfenced> <mml:mo>∗</mml:mo> </mml:mfenced> </mml:msup> <mml:msup> <mml:mi>ℓ</mml:mi> <mml:mo>−</mml:mo> </mml:msup> <mml:msub> <mml:mover> <mml:mi>ν</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>ℓ</mml:mi> </mml:msub> </mml:mrow> </mml:mfenced> </mml:mrow> </mml:mfrac> </mml:math> and the D ∗ longitudinal polarisation fraction $$ {F}_L^{D^{\ast }} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>F</mml:mi> <mml:mi>L</mml:mi> <mml:msup> <mml:mi>D</mml:mi> <mml:mo>∗</mml:mo> </mml:msup> </mml:msubsup> </mml:math> in different NP scenarios and extracted | V cb | which is consistent with the number mentioned above. Also, the simultaneous explanation of R ( D (∗) ) and $$ {F}_L^{D^{\ast }} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>F</mml:mi> <mml:mi>L</mml:mi> <mml:msup> <mml:mi>D</mml:mi> <mml:mo>∗</mml:mo> </mml:msup> </mml:msubsup> </mml:math> is not possible in the one-operator scenarios. However, the two operator scenarios with $$ {\mathcal{O}}_{S_2}^{\tau }=\left({\overline{q}}_R{b}_L\right)\left({\overline{\tau}}_R{\nu}_{\tau L}\right) $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>O</mml:mi> <mml:msub> <mml:mi>S</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:mi>τ</mml:mi> </mml:msubsup> <mml:mo>=</mml:mo> <mml:mfenced> <mml:mrow> <mml:msub> <mml:mover> <mml:mi>q</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>R</mml:mi> </mml:msub> <mml:msub> <mml:mi>b</mml:mi> <mml:mi>L</mml:mi> </mml:msub> </mml:mrow> </mml:mfenced> <mml:mfenced> <mml:mrow> <mml:msub> <mml:mover>

Topics & Concepts