论文标题
HQET中的约束二阶功率更正：$ r（d^{（*）}）$，$ | v_ {cb} | $和新物理
Constrained second-order power corrections in HQET: $R(D^{(*)})$, $|V_{cb}|$, and new physics
论文作者
论文摘要
我们假定在重夸克有效理论中的补充功率计数，这与标准方法相比，这会导致一组较小的，高度约束的二阶功率校正。我们确定所有$ \ bar {b} \至d^{（*）} $形式，无论是在标准模型内还是超出标准模型，即$ \ Mathcal {o}（α_s/m_s/m_ {c，b}，1/m_ {c，b}^2）$。我们表明，$ \ bar {b} \ to d^{（*）}lν$矩阵元素（$ l = e $，$μ$，$τ$）的零重新归一化的二阶功率更正已完全由Hadron Mass参数确定，并且与Lattice QCD（LQCD）预测符合lattice QCD（LQCD）的良好一致。我们在假定的截断下开发了这些形式因素的参数化，这非常适合可用的LQCD预测和实验数据，并且我们为$ \ bar {b} \提供精确的更新预测，以达到d^{（*）}τ\barν$ decay率，lepton风味的元素，lepton averational Interality Interality Imental Interry untracity Iment $ r（d^） $ | v_ {cb} | $。我们指出了有关$ \ Mathcal {O}（1/M_CM_B）$校正的先前文献中的一些明显错误，并注意常用的简化分散界和当前数据之间的张力。
We postulate a supplemental power counting within the heavy quark effective theory, that results in a small, highly-constrained set of second-order power corrections, compared to the standard approach. We determine all $\bar{B} \to D^{(*)}$ form factors, both within and beyond the standard model to $\mathcal{O}(α_s/m_{c,b}, 1/m_{c,b}^2)$, under truncation by this power counting. We show that the second-order power corrections to the zero-recoil normalization of the $\bar{B} \to D^{(*)} l ν$ matrix elements ($l = e$, $μ$, $τ$) are fully determined by hadron mass parameters, and are in good agreement with lattice QCD (LQCD) predictions. We develop a parametrization of these form factors under the postulated truncation, that achieves excellent fits to the available LQCD predictions and experimental data, and we provide precise updated predictions for the $\bar{B} \to D^{(*)} τ\barν$ decay rates, lepton flavor universality violation ratios $R(D^{(*)})$, and the CKM matrix element $|V_{cb}|$. We point out some apparent errors in prior literature concerning the $\mathcal{O}(1/m_cm_b)$ corrections, and note a tension between commonly-used simplified dispersive bounds and current data.
