Related papers: $\Lambda_b \to \Lambda \ell^+ \ell^-$ form factors…
Measurements of the $\Lambda_b \to p \ell^- \bar{\nu}_\ell$ and $\Lambda_b \to \Lambda_c \ell^- \bar{\nu}_\ell$ decay rates can be used to determine the magnitudes of the CKM matrix elements $V_{ub}$ and $V_{cb}$, provided that the relevant…
We present the first lattice QCD determination of the $\Lambda_b \to \Lambda^*(1520)$ vector, axial vector, and tensor form factors that are relevant for the rare decays $\Lambda_b \to \Lambda^*(1520)\ell^+\ell^-$. The lattice calculation…
We present the first lattice QCD determination of the $\Lambda_b \to \Lambda$ transition form factors that govern the rare baryonic decays $\Lambda_b \to \Lambda l^+ l^-$ at leading order in heavy-quark effective theory. Our calculations…
The rare baryonic decays $\Lambda_b \to \Lambda \mu^+ \mu^-$ and $\Lambda_b \to \Lambda \gamma$ can complement rare $B$ meson decays in constraining models of new physics. In this work, we calculate the relevant $\Lambda_b \to \Lambda$…
We calculate the $B \to\pi\ell\nu$ and $B_s \to K \ell\nu$ form factors in dynamical lattice QCD. We use the (2+1)-flavor RBC-UKQCD gauge-field ensembles generated with the domain-wall fermion and Iwasaki gauge actions. For the $b$ quarks…
We present a lattice QCD calculation of form factors for the decay $\Lambda_b \to p \mu^- \bar{\nu}$, which is a promising channel for determining the CKM matrix element $|V_{ub}|$ at the Large Hadron Collider. In this initial study we work…
We report the first lattice QCD calculation of the form factors for the standard model tree-level decay $B_s\to K \ell\nu$. In combination with future measurement, this calculation will provide an alternative exclusive semileptonic…
We present the first lattice QCD determination of the $\Xi_b \to \Xi$ vector, axial-vector, and tensor form factors, which are relevant for the theory of rare decays including $\Xi_b \to \Xi \ell^+\ell^-$ and $\Xi_b \to \Xi \gamma$. The…
The experimental uncertainty on the branching fraction $\b(\Lambda_c \to p K^- \pi^+) = (5.0 \pm 1.3)%$ has not decreased since 1998, despite a much larger data sample. Uncertainty in this quantity dominates that in many other quantities,…
We use HPQCD's recent lattice QCD determination of $B \to K$ scalar, vector and tensor form factors to determine Standard Model differential branching fractions for $B \to K \ell^+\ell^-$, $B\to K \ell_1^+\ell_2^-$ and $B \to K\nu…
The rare decay $B\to\pi\ell^+\ell^-$ arises from $b\to d$ flavor-changing neutral currents and could be sensitive to physics beyond the Standard Model. Here, we present the first $ab$-$initio$ QCD calculation of the $B\to\pi$ tensor form…
Experimental results for mesonic $b \to s \mu^+ \mu^-$ decays show a pattern of deviations from Standard-Model predictions, which could be due to new fundamental physics or due to an insufficient understanding of hadronic effects.…
We report on a two-flavour lattice QCD determination of the $B_s\to D_s$ and $B_s\to D_s^*$ transitions, which in the heavy quark limit can be parameterised by the form factors $\mathcal{G}$, and $h_{\text A_1}$, $h_{\text A_2}$ and…
The $\Lambda_b \rightarrow \Lambda_c \ell^- \bar{\nu}_\ell$ process has been discussed in the literatures as a probe for new physics. This process receives contributions in new physics models from scalar, vector, and tensor hadronic…
We compute the Standard Model semileptonic vector and axial-vector form factors for $B_s\to D_s^*$ decay across the full $q^2$ range using lattice QCD. We use the Highly Improved Staggered Quark (HISQ) action for all valence quarks,…
We calculate, for the first time using unquenched lattice QCD form factors, the Standard Model differential branching fractions $dB/dq^2(B \to Kll)$ for $l=e, \mu, \tau$ and compare with experimental measurements by Belle, BABAR, CDF, and…
We compute the form factors for the $B \to Kl^+l^-$ semileptonic decay process in lattice QCD using gauge-field ensembles with 2+1 flavors of sea quark, generated by the MILC Collaboration. The ensembles span lattice spacings from 0.12 to…
We present a lattice QCD determination of the $B_s \to D_s \ell\nu$ scalar and vector form factors over the full physical range of momentum transfer. The result is derived from correlation functions computed using the Highly Improved…
We calculate, for the first time using unquenched lattice QCD, form factors for the rare decay B -> Kll in and beyond the Standard Model. Our lattice QCD calculation utilizes a nonrelativistic QCD formulation for the b valence quarks, the…
Precise theoretical predictions derived from the Standard Model are a key ingredient in searches for new physics in the flavor sector. The large mass and long lifetime of the $b$ quark make processes involving $b$ quarks of particular…