论文标题
联合晶格QCD-分散理论分析证实了夸克的顶峰赤字
Joint lattice QCD - dispersion theory analysis confirms the quark-mixing top-row unitarity deficit
论文作者
论文摘要
最近，对$γw$ -box辐射校正的第一次晶格计算对半蛋白pion衰变的速率校正使该速率的理论不确定性降低了$ \ sim3 $。对中子中$γw$ - 盒校正的最新分散评估也导致了理论不确定性的显着降低，但转移了从中子中提取的$ v_ {ud} $的价值，从而使核$β$衰减从中子中提取，从而导致了顶轮CKM Unitarity的不足。对中子衰减的$γw$盒校正的直接晶格计算将为此结果提供独立的交叉检查，但非常具有挑战性。在克服这些挑战之前，我们提出了杂种分析，将裂缝上的晶格计算通过分散理论和现象学输入的组合转换为中子上的中子。通用辐射校正的新预测与中子$β$ -decay读取$Δ_R^v = 0.02477（24）$，与分散理论结果$Δ_R^v = 0.02467（22）$非常吻合。结合其他相关信息，顶峰CKM单位性赤字仍然存在。
Recently, the first ever lattice computation of the $γW$-box radiative correction to the rate of the semileptonic pion decay allowed for a reduction of the theory uncertainty of that rate by a factor of $\sim3$. A recent dispersion evaluation of the $γW$-box correction on the neutron also led to a significant reduction of the theory uncertainty, but shifted the value of $V_{ud}$ extracted from the neutron and superallowed nuclear $β$ decay, resulting in a deficit of the CKM unitarity in the top row. A direct lattice computation of the $γW$-box correction for the neutron decay would provide an independent cross-check for this result but is very challenging. Before those challenges are overcome, we propose a hybrid analysis, converting the lattice calculation on the pion to that on the neutron by a combination of dispersion theory and phenomenological input. The new prediction for the universal radiative correction to free and bound neutron $β$-decay reads $Δ_R^V=0.02477(24)$, in excellent agreement with the dispersion theory result $Δ_R^V=0.02467(22)$. Combining with other relevant information, the top-row CKM unitarity deficit persists.
