论文标题
来自$ \ mathit {on \ text { - } shell} $ scualar交换
Neutral $B$-anomalies from an $\mathit{on\text{-}shell}$ scalar exchange
论文作者
论文摘要
中立$ b $ - nothemalies是根据（伪）标量表单元$ a $的树级交换来分析的。 Solutions to both $R_{K^{(*)}}$ central bin anomalies are found within $1σ$ for ${m_{a}^2 \in [{1.1},\,{6}]\,\text{GeV}^2}$, while the low $q^2$-bin anomaly can also be accounted for with masses close to the bin threshold.这些解决方案对其他$ {b \ s e^+ e^ - } $可观察到的影响进行了详细讨论。由于$ \ mathit {on \ text { - } shell} $增强，因此在$ b \ to k e^+ e^ - $ angular Distribution的null测试中预计会有很大的效果。同时，可观察到的对$ k^\ ast $极化的敏感，$ f_l \，（b \ to k^* e^+ e^ - ）$，以及Lepton Forward-backward不对称，$ {a_ {a_ {fb} \，（b \ to k^* e^* e^e^+ e^ - ）可以被抑制，以抑制他们的尊重。另一方面，从新物理学到$ \ Mathcal {b}（b_s \ to e^+ e^ - ）$更正是可以忽略的。除了先前的观测值外，横截面$ {σ（E^+ E^ - \ \ to A（e^+ e^ - ）γ）} $的改进测量可能有可能探测模型的相关参数空间。还讨论了我们的结果与来自轴突状颗粒交换的结果之间的比较，表明一般标量单元的交换提供了明显较宽的参数空间。
The neutral $B$-anomalies are analysed in terms of the tree-level exchange of a (pseudo)scalar gauge singlet $a$. Solutions to both $R_{K^{(*)}}$ central bin anomalies are found within $1σ$ for ${m_{a}^2 \in [{1.1},\,{6}]\,\text{GeV}^2}$, while the low $q^2$-bin anomaly can also be accounted for with masses close to the bin threshold. The impact of these solutions on other ${b\to s e^+ e^-}$ observables is discussed in detail. Due to the $\mathit{on\text{-}shell}$ enhancement, sizable effects are expected in null tests of the SM, such as the flat term, $F_H$, of the $B\to K e^+ e^-$ angular distribution. At the same time, the observable sensitive to the $K^\ast$ polarisation, $F_L\, (B\to K^* e^+ e^-)$, and the lepton forward-backward asymmetry, ${A_{FB}\, (B\to K^* e^+ e^-)}$, can be suppressed with respect to their SM values. Corrections from the new physics to $\mathcal{B}(B_s \to e^+ e^-)$ are, on the other hand, negligible. Along with the previous observables, improved measurements of the cross section ${σ(e^+ e^- \to a (e^+ e^-) γ)}$ could potentially probe the relevant parameter space of the model. A comparison between our results and those stemming from an axion-like particle exchange is also discussed, showing that the exchange of a general scalar singlet offers a noticeably wider parameter space.
