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arXiv 1804.02401hep-phhep-exhep-lat
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从格点量子色动力学研究QCD强子矩阵元对$K^0-\bar K^0$混合的双重作用

Dual QCD Insight into BSM Hadronic Matrix Elements for $K^0-\bar K^0$ Mixing from Lattice QCD

Andrzej J. Buras, Jean-Marc Gerard

摘要:

用双QCD方法计算了$K^0-\bar K^0$混合的BSM强子矩阵元。ETM、SWME和RBC-UKQCD晶格合作发现BSM密度-密度算符$\mathcal{O}_i$和$i=2-5$的矩阵元与它们在$μ=3~GeV$处的$B_2\approx 0.5$、$B_3\approx B_5\approx 0.7$和$B_4\approx 0.9$的真空插入值(VIA)相当不同,以与VIA中的$B_i=1$进行比较。我们证明,这种模式可以重建内的DQCD通过非微扰介子演化从非常低的尺度,其中矩阵元素的因式分解是有效的,为了$(1~GeV)$的规模与随后的微扰夸克胶子演化$μ=3~GeV$。这证明是可能的,尽管在低尺度下显示出非常不同的模式,其中$B_2=1.2$、$B_3=3.0$、$B_4=1.0$和$B_5\approx 0.2$在大的$N$极限中,$N$是颜色的数量。我们的结果意味着在任何非轻子跃迁的现象学,如$K^0-\bar K^0$混合和$K\toππ$衰变中包含介子演化是强制性的。虽然介子演化,正如我们的论文中所展示的,是隐藏在LQCD的结果,据我们所知,DQCD是唯一的分析方法,非轻子跃迁和衰变,考虑到这一重要的QCD动力学。

英文摘要:

We calculate BSM hadronic matrix elements for $K^0-\bar K^0$ mixing in the Dual QCD approach (DQCD). The ETM, SWME and RBC-UKQCD lattice collaborations find the matrix elements of the BSM density-density operators $\mathcal{O}_i$ with $i=2-5$ to be rather different from their vacuum insertion values (VIA) with $B_2\approx 0.5$, $B_3\approx B_5\approx 0.7$ and $B_4\approx 0.9$ at $μ=3~GeV$ to be compared with $B_i=1$ in the VIA. We demonstrate that this pattern can be reconstructed within the DQCD through the non-perturbative meson evolution from very low scales, where factorization of matrix elements is valid, to scales of order $(1~GeV)$ with subsequent perturbative quark-gluon evolution to $μ=3~GeV$. This turns out to be possible in spite of a very different pattern displayed at low scales with $B_2=1.2$, $B_3=3.0$, $B_4=1.0$ and $B_5\approx 0.2$ in the large $N$ limit, $N$ being the number of colours. Our results imply that the inclusion of meson evolution in the phenomenology of any non-leptonic transition like $K^0-\bar K^0$ mixing and $K\toππ$ decays is mandatory. While meson evolution, as demonstrated in our paper, is hidden in LQCD results, to our knowledge DQCD is the only analytic approach for non-leptonic transitions and decays which takes this important QCD dynamics into account.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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