论文标题
$ b \ to c $测量对$λ_B\ topτ\barν$衰减的影响
Impact of $b \to c$ measurements on $Λ_b \to p τ\barν$ decay in $U_1$ leptoquark model
论文作者
论文摘要
夸克级过渡$ b \ tocτ\barν$在衰减中违反观察力的几种轻顿风味普遍性（LFU）的测量值超出了电动型相互作用的标准模型。这种新物理学也会影响其他部门。在这项工作中，我们估计$ b \ in $λ_b\ on $ b \ tocτ\barν$在$ u_1 $ leptoquark模型的情况下的杠杆作用。在此模型中，可以用$ b \ to $ b \ toCτ\barν$耦合来编写$ b \ touτ\barν$过渡的新物理耦合，因此可以通过$λ_b\ topτ\barν$确定允许新物理学的范围。使用通过对所有$ b \cτ\barν$数据进行拟合来获得的新物理参数空间，我们获得了几个$λ_b\ \ topτ\barν$可观察的预测。我们发现当前的$ b \cτ\barν$数据允许分支比和LFU比的数量级增强。其他可观察到的物品，例如凸参数，Lepton前后不对称，最终状态BARYON和TAU LEPTON的纵向极化与SM值一致。
The measurements of several lepton flavor universality (LFU) violating observables in the decays induced by the quark level transition $b \to c τ\barν$ provide an inkling of plausible physics beyond the standard model of electroweak interactions. Such new physics would also impact other sectors. In this work, we estimate the leverage of new physics in $b \to c τ\barν$ on $Λ_b \to p τ\barν$ decay in the context of $U_1$ leptoquark model. In this model, the new physics couplings in $b \to u τ\barν$ transition can be written in terms of $b \to c τ\barν$ couplings and hence the extent of allowed new physics in $Λ_b \to p τ\barν$ would be determined by $b \to c τ\barν$ transition. Using the new physics parameter space obtained by performing a fit to all $b \to c τ\barν$ data, we obtain predictions of several $Λ_b \to p τ\barν$ observables. We find that the current $b \to c τ\barν$ data allows an order of magnitude enhancement in the branching ratio as well as in the LFU ratio. The other observables such as convexity parameter, lepton forward-backward asymmetry, longitudinal polarization of final state baryon and tau lepton are consistent with the SM value.
