论文标题
$ b_s \ to K^+k^ - $的LHCB测量CP违规的经验教训
Lessons from the LHCb measurement of CP violation in $B_s\to K^+K^-$
论文作者
论文摘要
LHCB实验测量了$ b_s \ in $ b_s \ to k^+k^ - $ decay中的时间依赖于时间依赖的cp不对称$ c_ {kk} $。与相应的CP不对称结合$ C_ {ππ} $和$ s_ {ππ} $中的$ b \ toπ^+π^ - $ decay，我们发现该系统中$ u $ -spin破裂的大小为$ 20 \％$。此外，数据表明这些效果由可因素的贡献主导。我们进一步研究了对$ b \ u \ bar uq $（$ q = s，d $）的新物理贡献的限制。在这些衰减中，违反最小风味的新物理学（MFV）不能与标准模型（SM）区分开。但是，不是MFV的新物理学可以模仿大型$ u $ spin破裂。要求$ u $ spin断裂参数保持在数据所隐含的大小以下，导致$ 5-10 $ tev的下限在通用新物理学的规模上。如果新物理学受到Froggatt-Nielsen（FN）机制或一般性最小风味（GMFV）的选择规则的约束，则该结合将放松至2 TEV。
The LHCb experiment measured the time-dependent CP asymmetries $C_{KK}$ and $S_{KK}$ in $B_s\to K^+K^-$ decay. Combining with the corresponding CP asymmetries $C_{ππ}$ and $S_{ππ}$ in $B\to π^+π^-$ decay, we find that the size of $U$-spin breaking in this system is of order $20\%$. Moreover, the data suggest that these effects are dominated by factorizable contributions. We further study the constraints on new physics contributions to $b\to u\bar uq$ ($q=s,d$). New physics that is minimally flavor violating (MFV) cannot be distinguished from the Standard Model (SM) in these decays. However, new physics that is not MFV can mimic large $U$-spin breaking. Requiring that the $U$-spin breaking parameters remain below the size implied by the data leads to a lower bound of $5-10$ TeV on the scale of generic new physics. If the new physics is subject to the selection rules that follow from the Froggatt-Nielsen (FN) mechanism or from General Minimal Flavor Violation (GMFV), the bound is relaxed to 2 TeV.
