论文标题
$ b_ {d，s} \ to k^{*0} \ bar {k}^{*0} $中的新的$ b $ -flavour异常
A new $B$-flavour anomaly in $B_{d,s}\to K^{*0}\bar{K}^{*0}$: anatomy and interpretation
论文作者
论文摘要
在最近测量的非静态衰减的上下文中，$ b_ {d} \ to k^{*0} \ bar {k}^{*0} $和$ b_ {s} \ to k^{*0} {*0} \ bar {k}^{*0} $ long os os os ot o the $ l_} $ b_s \ to vv $和$ b_d \ to vv $衰减的组件。可观察到的可清洁比纵向极化部分更干净，因为它仅以$ 1/m_b $膨胀的折磨，这是由于进入极化分数的横向组件中产生的理论不确定性。专注于$ b_ {d} \的特定情况，至k^{*0} \ bar {k}^{*0} $和$ b_ {s} \ to k^{*0} \ bar {k}^{*0} $，我们讨论了Smeronic Incnestity的主源。我们找到了SM预测$ l_ {k^*\ bar {k}^*} = 19.5^{+9.3} _ { - 6.8} $，这意味着相对于最新数据，$2.6σ$张力指向$ b \ to y to nonthen-le-Lepleption $ le-le-le-le-le-le-le-le-lepterpent $ the $ bedy $ be dy $ by by dy $ b b by by by vers y vers y versus vers vers vers vers vers vers vers vers versus vers vers vers vers vers vers。我们讨论了这种偏差的新物理解释，首先是在弱有效理论的水平上，我们确定两个威尔逊系数$ {\ cal c} _ {4} $和$ {\ cal c} _ {8G} $可以在解释这种厌氧方面起核心作用。最后，我们简要探讨了两个不同的简化新物理模型，可以通过$ {\ cal c} _4 $（kaluza-klein gluon）或$ {\ cal c} _ {8G} $中的贡献来解释异常，但可以进行$ b \ y \ y \ y \ Ell。
In the context of the recently measured non-leptonic decays $B_{d}\to K^{*0}\bar{K}^{*0}$ and $B_{s}\to K^{*0}\bar{K}^{*0}$ we analyse the anatomy of the $L_{VV}$ observable that compares the longitudinal components of $B_s \to VV$ and $B_d \to VV$ decays. This observable is cleaner than the longitudinal polarisation fraction as it is afflicted only at subleading order in a $1/m_b$ expansion by the theoretical uncertainties arising in the transverse components entering the polarisation fraction. Focusing on the particular case of $B_{d}\to K^{*0}\bar{K}^{*0}$ and $B_{s}\to K^{*0}\bar{K}^{*0}$, we discuss the main sources of hadronic uncertainty in the SM. We find for the SM prediction $L_{K^*\bar{K}^*}=19.5^{+9.3}_{-6.8}$, which implies a $2.6σ$ tension with respect to the most recent data, pointing to a deficit in the $b \to s$ transition of the non-leptonic decay versus the corresponding $b \to d$ transition. We discuss possible New Physics explanations for this deviation, first at the level of the Weak Effective Theory and we identify that the two Wilson coefficients ${\cal C}_{4}$ and ${\cal C}_{8g}$ can play a central role in explaining this anomaly. Finally, we briefly explore two different simplified New Physics models which can explain the anomaly through a contribution either in ${\cal C}_4$ (Kaluza-Klein gluon) or in ${\cal C}_{8g}$, with a significant amount of fine tuning, but possible connections to the $b \to s \ell \ell$ anomalies.
