Testing leptoquark models in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mover accent="true"><mml:mi>B</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mo>→</mml:mo><mml:msup><mml:mi>D</mml:mi><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mo>*</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:msup><mml:mi>τ</mml:mi><mml:mover accent="true"><mml:mi>ν</mml:mi><mml:mo>¯</mml:mo></mml:mover></mml:math> 论文

摘要

We study potential new physics effects in the $\overline{B}\ensuremath{\rightarrow}{D}^{(*)}\ensuremath{\tau}\overline{\ensuremath{\nu}}$ decays. As a particular example of new physics models, we consider the class of leptoquark models and put the constraints on the leptoquark couplings using the recently measured ratios $R({D}^{(*)})=\mathcal{B}(\overline{B}\ensuremath{\rightarrow}{D}^{(*)}\ensuremath{\tau}\overline{\ensuremath{\nu}})/\mathcal{B}(\overline{B}\ensuremath{\rightarrow}{D}^{(*)}\ensuremath{\mu}\overline{\ensuremath{\nu}})$. For consistency, some of the constraints are compared with the ones coming from the current experimental bound on $\mathcal{B}(B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\nu}\overline{\ensuremath{\nu}})$. In order to discriminate various new physics scenarios, we examine the correlations between different observables that can be measured in the future.