? b ? p l - ? ¯ l form factors from lattice QCD with static b quarks
? b ? p l - ? ¯ l form factors from lattice QCD with static b quarks
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DOI：
10.1103/physrevd.88.014512
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发表时间：
2013
影响因子：
5
通讯作者：
Detmold W
中科院分区：
文献类型：
--
作者：
Detmold W
我们提出了一个格点QCD计算衰变的形状因子，这是一个有前途的渠道，确定Cabibbo-Kobayashi-Maskawa矩阵元素在大型强子对撞机。在这个初步的研究中，我们在静态夸克的极限下工作，其中独立形状因子的数量减少到两个。我们使用动力学域壁费米子的轻夸克，并在两个不同的晶格间距和在一个单一的大体积的轻夸克质量的多个值进行计算。利用我们的形状因子结果，我们计算了14 GeV ~ 2 ≤ q ~ 2 ≤ q_（max）~（<$2）范围内的微分衰变率，并得到了积分公式<$14 GeV ~ 2 q_（max）~（<$2 [d ~ Γ/dq ~ 2] dq ~ 2/|VUB| 2=15.3±4.2 ps-1。结合未来的实验数据，这将给出一个新的测量方法，理论不确定度约为15%.这种不确定性主要是由夸克的静态近似决定的，并且可以通过用更复杂的重夸克作用量进行晶格计算来进一步减少。
We present a lattice QCD calculation of form factors for the decay, which is a promising channel for determining the Cabibbo-Kobayashi-Maskawa matrix elementat the Large Hadron Collider. In this initial study we work in the limit of staticquarks, where the number of independent form factors reduces to two. We use dynamical domain-wall fermions for the light quarks, and perform the calculation at two different lattice spacings and at multiple values of the light-quark masses in a single large volume. Using our form factor results, we calculate thedifferential decay rate in the range 14 GeV2≤q2≤qmax2, and obtain the integral ∫14 GeV2qmax2[dΓ/dq2]dq2/|Vub|2=15.3±4.2 ps-1. Combined with future experimental data, this will give a novel determination ofwith about 15% theoretical uncertainty. The uncertainty is dominated by the use of the static approximation for thequark, and can be reduced further by performing the lattice calculation with a more sophisticated heavy-quark action.