Study of intermediate states in the inclusive semileptonic $B \rightarrow X_c l ν$ decay structure function

Inclusive semileptonic $Λ_b$ decays in the Standard Model and beyond

Inclusive semileptonic decays of beauty baryons are studied using the heavy quark expansion to ${\cal O}(1/m_b^3)$, at leading order in $α_s$. The case of a polarized decaying baryon is examined, with reference to $Λ_b$. An extension of the Standard Model effective Hamiltonian inducing $b \to U \ell {\bar ν}_ \ell$ transitions ($U=u,\,c$ and $\ell=e,\,μ,\,τ$) is considered, which comprises the full set of D=6 semileptonic operators with left-handed neutrinos. The effects of the new operators in several observables are described.

Form factor ratios for $B_s \rightarrow K \, \ell \, ν$ and $B_s \rightarrow D_s \, \ell \, ν$ semileptonic decays and $|V_{ub}/V_{cb}|$

We present a lattice quantum chromodynamics determination of the ratio of the scalar and vector form factors for two semileptonic decays of the $B_s$ meson: $B_s \rightarrow K \ell ν$ and $B_s \rightarrow D_s \ell ν$. In conjunction with future experimental data, our results for these correlated form factors will provide a new method to extract $|V_{ub}/V_{cb}|$, which may elucidate the current tension between exclusive and inclusive determinations of these Cabibbo-Kobayashi-Maskawa mixing matrix parameters. In addition to the form factor results, we determine the ratio of the differential dec…

重费米子衰变的包容性和排他性半轻子衰变的格点计算

Inclusive and exclusive semileptonic decays of heavy mesons on the lattice

本研究通过格点QCD四点相关函数直接提取重费米子衰变的可观测量，探讨了包容性和排他性半轻子衰变的统一处理方法，以解决Vcb谜题。

$D_{s}$ 介子的包容性半轻子衰变：格点 QCD 面对实验

Inclusive semileptonic decays of the $D_{s}$ meson: Lattice QCD confronts experiments

本研究通过考虑所有系统误差的最先进格点 QCD 计算对 $D_{s}$ 介子包容性半轻子衰变进行第一性原理分析，发现其衰变率与前两个轻子能量矩的理论预测与实验高度吻合，并指出该通道未来在确定 $|V_{cs}|$ 时有望显著提升竞争力。

The Heavy Quark Expansion for Inclusive Semileptonic Charm Decays Revisited

The Heavy Quark Expansion (HQE) has become an extremely powerful tool in flavor physics. For charm decays, where the expansion parameters $α_s(m_c)$ and $Λ_{\rm QCD}/m_c$ are bigger than for bottom decays, it remains to be seen if the HQE can be applied with similar success. Nevertheless, to make optimal use of the plethora of data already available and coming in the near future, a better understanding of HQE for charm decays is crucial. This paper discusses in detail how the HQE for charm decays is set up, what is the role of four-quark (weak annihilation) operators and how this compares to t…

$D \rightarrow π, l ν$ Semileptonic Decays, $|V_{cd}|$ and 2$^{nd}$ Row Unitarity from Lattice QCD

We present a new calculation of the $D \rightarrow π, l ν$ semileptonic form factor $f^{D \rightarrow π}_+(q^2)$ at $q^2 = 0$ based on HISQ charm and light valence quarks on MILC $N_f = 2 +1$ lattices. Using methods developed recently for HPQCD's study of $D \rightarrow K, l ν$ decays, we find $f^{D \rightarrow π}_+(0) = 0.666(29)$. This signifies a better than factor of two improvement in errors for this quantity compared to previous calculations. Combining the new result with CLEO-c branching fraction data, we extract the CKM matrix element $|V_{cd}| = 0.225(6)_{exp.}(10)_{lat.}$, where the …

基于格点QCD研究含半轻子$B_{(s)}$介子衰变的方法

Approaches to inclusive semileptonic $B_{(s)}$-meson decays from Lattice QCD

本文提出用格点QCD非微扰计算半轻子$B_{(s)}$介子含衰变率，并通过$B_s \ ightarrow X_c l\ u_l$试点计算比较Chebyshev与Backus-Gilbert方法。

基于格点模拟研究贡献于$ B_s $到$D_s$遍举半轻衰变的$P$波形状因子

Study on the $P$-wave form factors contributing to $ B_s $ to $D_s$ inclusive semileptonic decays from lattice simulations

本研究基于$24^3\times 64$粗格点，从$B_s$四点关联子提取$P$波形状因子并计算Isgur-Wise形状因子，发现径向激发对零反冲下的Uraltsev求和规则贡献显著。

遍举半轻衰变格点计算中的系统效应

Systematic effects in the lattice calculation of inclusive semileptonic decays

本研究利用莫比乌斯畴壁粲夸克与奇异夸克格点模拟遍举半轻衰变过程，覆盖全部运动学区域，重点更新近似策略选择与有限体积效应带来的系统不确定性估算方法。

$D \rightarrow K, l ν$ Semileptonic Decay Scalar Form Factor and $|V_{cs}|$ from Lattice QCD

We present a new study of D semileptonic decays on the lattice which employs the Highly Improved Staggered Quark (HISQ) action for both the charm and the light valence quarks. We work with MILC unquenched $N_f = 2 + 1$ lattices and determine the scalar form factor $f_0(q^2)$ for $D \rightarrow K, l ν$ semileptonic decays. The form factor is obtained from a scalar current matrix element that does not require any operator matching. We develop a new approach to carrying out chiral/continuum extrapolations of $f_0(q^2)$. The method uses the kinematic "$z$" variable instead of $q^2$ or the kaon ene…

$D_s$ 介子的包容性半轻子衰变：第一性原理格点 QCD 计算

Inclusive semileptonic decays of the $D_s$ meson: A first-principles lattice QCD calculation

本文利用 ETMC 格点 QCD 系综和 HLT 方法，首次从第一性原理计算了 $D_s$ 介子包容性半轻子衰变率及轻子能量矩，结果与实验相符且达百分之几精度，证明了格点方法研究重介子包容性衰变的可行性。

Semileptonic decays $B\rightarrow D^{(*)}lν$ at nonzero recoil

We have analyzed the semileptonic decays $B\rightarrow D\ellν$ and $B\rightarrow D^*\ellν$ on the full suite of MILC (2+1)-flavor asqtad ensembles with lattice spacings as small as 0.045 fm and light-to-strange-quark mass ratios as low as 1/20. We use the Fermilab interpretation of the clover action for heavy valence quarks and the asqtad action for light valence quarks. We compute the hadronic form factors for $B\rightarrow D$ at both zero and nonzero recoil and for $B\rightarrow D^*$ at zero recoil. We report our results for $|V_{cb}|$.

粲介子包含半轻子衰变中有限体积效应的研究

Studies on finite-volume effects in the inclusive semileptonic decays of charmed mesons

本研究在格点上计算$D_s$介子包含半轻子衰变，重点分析有限体积效应，通过构建双体末态模型研究向无限体积极限的外推。

Semileptonic $Λ_{b}\rightarrow Λ_{c}{\ell}\barν_{\ell}$ Transition in Full QCD

The tree-level $b\rightarrow c{\ell}\barν_{\ell}$ based hadronic transitions have been on the focus of much attention since recording significant deviations of the experimental data, on the ratios of the branching fractions in $ τ$ and $ e-μ$ channels of the semileptonic $ B \rightarrow D $ transition, from the SM predictions by BaBar Collaboration in 2012. It can be of great importance to look whether similar discrepancies take place in the semileptonic baryonic $Λ_{b}\rightarrow Λ_{c}{\ell}\barν_{\ell}$ decay channel or not. In this accordance we estimate the decay width as well as the ratio…

Semileptonic $D \rightarrow π\ell ν$, $D \rightarrow K \ell ν$ and $D_s \rightarrow K \ell ν$ decays with 2+1f domain wall fermions

We present the status of our project to calculate $D \to π\ell ν$, $D \to K \ell ν$ and $D_s \to K \ell ν$ semileptonic form factors using domain wall fermions for both heavy and light quarks. Our computations are performed using RBC/UKQCD's set of 2+1 flavour domain wall fermion and Iwasaki gauge field ensembles. We plan to calculate three-point functions covering the full, physically allowed kinematic range. Given that the signal decays faster than the noise, unambiguously and reliably extracting the ground state is critical for success. We include an analysis of operator diagonalisation wit…

Kolya：一个用于包容性半轻子$B$衰变的开源软件包

Kolya: an open-source package for inclusive semileptonic $B$ decays

Kolya是一个开源Python库，基于重夸克展开和动能方案计算包容性半轻子$B$衰变的总速率与运动学矩，包含幂次与QCD微扰修正，并支持新物理效应与CRunDec接口，用于唯象分析。

QCD求和规则中半轻子衰变 $Σ_{b}^{*0}\\,\rightarrow\\, Σ_{c}^{+}\\,\ell\\,\barν_{\ell}$ 跃迁的唯象学研究

Phenomenology of the semileptonic $Σ_{b}^{*0}\,\rightarrow\, Σ_{c}^{+}\,\ell\,\barν_{\ell}$ transition within QCD sum rules

本文利用三点QCD求和规则计算了$Σ_{b}^{*0}\rightarrow Σ_{c}^{+}\ell\barν_{\ell}$半轻子衰变的形状因子和衰变宽度，为检验标准模型及探索重味重子衰变中的新物理提供理论依据。

对半轻衰变 $Ξ^{(')}_{b}\rightarrow Ξ^{(')}_{c}{\ell}\barν_{\ell}$ 的研究

Investigation of the semileptonic decays $Ξ^{(')}_{b}\rightarrow Ξ^{(')}_{c}{\ell}\barν_{\ell}$

本文利用 QCD 求和规则研究 $Ξ^{(')}_{b}\rightarrowΞ^{(')}_{c}{\ell}\barν_{\ell}$ 半轻衰变，计算所有轻子道的衰变宽度与分支比，并与其他理论结果比较，为未来对撞机实验检验标准模型提供参考。

对$b \to c$包络半轻子衰变系统效应的研究

Study on the systematic effects on $b \to c$ inclusive semileptonic decays

本文通过格点QCD计算$B_s \to X_c l ν_l$衰变，探讨系统误差来源，包括雅各比平滑的影响、源-汇分离变化及包络重建方法的固有不确定性，并展示如何通过将地面态贡献视为排除性衰变来抑制系统误差。

在QCD求和规则下研究半轻衰变 $ Ξ^{++}_{cc}\rightarrow Ξ^+_{c} \bar{\ell}ν_{\ell}$

Investigation of the semileptonic decay $ Ξ^{++}_{cc}\rightarrow Ξ^+_{c} \bar{\ell}ν_{\ell}$ within QCD sum rules

本文利用三点QCD求和规则计算双重重子Ξcc++到Ξc+的半轻衰变形状因子，并预测衰变宽度和分支比，为LHCb等实验寻找双重重子弱衰变提供理论参考。

$D \rightarrow Klν$ semileptonic decay using lattice QCD with HISQ at physical pion masses

The quark flavor sector of the Standard Model is a fertile ground to look for new physics effects through a unitarity test of the Cabbibo-Kobayashi-Maskawa (CKM) matrix. We present a lattice QCD calculation of the scalar and the vector form factors (over a large $q^2$ region including $q^2 = 0$) associated with the $D \rightarrow Klν$ semi-leptonic decay. This calculation will then allow us to determine the central CKM matrix element, $V_{cs}$ in the Standard Model, by comparing the lattice QCD results for the form factors and the experimental decay rate. This form factor calculation has been …

Chebyshev与Backus-Gilbert重构：从格点QCD研究包含半轻子$B_{(s)}$介子衰变

Chebyshev and Backus-Gilbert reconstruction for inclusive semileptonic $B_{(s)}$-meson decays from Lattice QCD

本研究用格点QCD比较Chebyshev与Backus-Gilbert方法分析B_s介子包含半轻子衰变，计算总衰变率与矩，旨在缓解CKM矩阵元$|V_{cb}|$和$|V_{ub}|$的张力。

QCD中半轻子\(Ω_{b}^{*}\rightarrowΩ_{c}^{*} \ell \barν_{\ell}\)跃迁

Semileptonic $Ω_{b}^{*}\rightarrowΩ_{c}^{*} \ell \barν_{\ell}$ transition in QCD

利用QCD求和规则方法研究\(\Omega_{b}^{*}\)到\(\Omega_{c}^{*}\)的半轻子弱衰变，计算三点关联函数推导形状因子求和规则，经数值计算提取拟合函数，用于计算衰变宽度，为相关实验研究提供理论基准。