论文标题
$ b $异常和非湿度新物理
The $B$ Anomalies and non-SMEFT New Physics
论文作者
论文摘要
现代的观点是，标准模型是有效场理论的主要部分，该理论遵守对称性$ su（3）_c \ times su（2）_l \ times u（1）_y $。由于发现了希格斯玻色子，因此通常假定这种对称性是线性实现的（SMEFT），但是仍然有可能实现非线性实现（例如，heft）。他们对某些低能尺寸的大小的预测有所不同：为此，Heft允许$ O（1）$耦合，而在Smeft中，它们被因子$ v^2/λ_{\ rm np}^2 $抑制，其中$ v $是$ v $，其中$ v $是higgs vev。在这次演讲中，我认为（i）这样的非Smeft操作员都为$ b \ to s \ ell^+ \ ell^ - $ and $ b \ to c \ to c \，τ^ - {\barν}_τ$，在当今的$ b $ be nomalies，（ii）的$ b \ ell^eell^eell^eell^eell^eell^eell^eell^eell^eell^eell^eell^smbion^e \^eell^e \^的过渡中smeft级别，（iii）$ b \对c \，τ^ - {\barν}_τ$的贡献很大。我表明，$ {\ bar b} \ to d^*（\ todπ'）\，τ^{ - }（\toπ^ - ν_τ）{\barν}_τ$包含足够的信息以提取所有新播种机的系数。该角度分布的测量可以告诉我们是否存在非弱新物理学。
The modern viewpoint is that the Standard Model is the leading part of an effective field theory that obeys the symmetry $SU(3)_C \times SU(2)_L \times U(1)_Y$. Since the discovery of the Higgs boson, it is generally assumed that this symmetry is realized linearly (SMEFT), but a nonlinear realization (e.g., HEFT) is still possible. The two differ in their predictions for the size of certain low-energy dimension-6 four-fermion operators: for these, HEFT allows $O(1)$ couplings, while in SMEFT they are suppressed by a factor $v^2/Λ_{\rm NP}^2$, where $v$ is the Higgs vev. In this talk, I argue that (i) such non-SMEFT operators contribute to both $b \to s \ell^+ \ell^-$ and $b \to c \,τ^- {\barν}_τ$, transitions involved in the present-day $B$ anomalies, (ii) the contributions to $b \to s \ell^+ \ell^-$ are constrained to be small, at the SMEFT level, and (iii) the contribution to $b \to c \,τ^- {\barν}_τ$ can be sizeable. I show that the angular distribution in ${\bar B} \to D^* (\to D π') \, τ^{-} (\to π^- ν_τ) {\barν}_τ$ contains enough information to extract the coefficients of all new-physics operators. The measurement of this angular distribution can tell us if non-SMEFT new physics is present.
