quark: mass dependence

$B_s$ to $K \ell \nu$ decay from lattice QCD

We use lattice QCD to calculate the form factors f+(q2) and f0(q2) for the semileptonic decay Bs→Kℓν. Our calculation uses six MILC asqtad 2+1 flavor gauge-field ensembles with three lattice spacings. At the smallest and largest lattice spacing the …

$|V_{us}|$ from $K_{\ell 3}$ decay and four-flavor lattice QCD

Using highly improved staggered quark (HISQ) Nf=2+1+1 MILC ensembles with five different values of the lattice spacing, including four ensembles with physical quark masses, we perform the most precise computation to date of the K→πℓν vector form …

Radiative Contribution to the Composite-Higgs Potential in a Two-Representation Lattice Model

Working in a two-representation lattice gauge theory that is close to a composite-Higgs model, we calculate the low-energy constant CLR which controls the contribution of the electroweak gauge bosons to the Higgs potential. In QCD, the corresponding …

$B$- and $D$-meson leptonic decay constants from four-flavor lattice QCD

We calculate the leptonic decay constants of heavy-light pseudoscalar mesons with charm and bottom quarks in lattice quantum chromodynamics on four-flavor QCD gauge-field configurations with dynamical u, d, s, and c quarks. We analyze over twenty …

Up-, down-, strange-, charm-, and bottom-quark masses from four-flavor lattice QCD

We calculate the up-, down-, strange-, charm-, and bottom-quark masses using the MILC highly improved staggered-quark ensembles with four flavors of dynamical quarks. We use ensembles at six lattice spacings ranging from a≈0.15 to 0.03 fm and with …

Short-distance matrix elements for $Dtextasciicircum0$-meson mixing for $N_f=2+1$ lattice QCD

We calculate in three-flavor lattice QCD the short-distance hadronic matrix elements of all five ΔC=2 four-fermion operators that contribute to neutral D-meson mixing both in and beyond the Standard Model. We use the MILC Collaboration’s Nf=2+1 …

$Btextasciicircum0_(s)$-mixing matrix elements from lattice QCD for the Standard Model and beyond

We calculate—for the first time in three-flavor lattice QCD—the hadronic matrix elements of all five local operators that contribute to neutral B0- and Bs-meson mixing in and beyond the Standard Model. We present a complete error budget for each …

$Bto Kltextasciicircum+ltextasciicircum-$ Decay Form Factors from Three-Flavor Lattice QCD

We compute the form factors for the B→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 0.045 fm and have …

Update of $textbarV_b̧textbar$ from the $barBto Dtextasciicircum*ellbarnu$ form factor at zero recoil with three-flavor lattice QCD

We compute the zero-recoil form factor for the semileptonic decay $barBtextasciicircum0to Dtextasciicircum*+elltextasciicircum-barnu$ (and modes related by isospin and charge conjugation) using lattice QCD with three flavors of sea quarks. We use an …

Kaon semileptonic vector form factor and determination of textbarV_ustextbar using staggered fermions

Using staggered fermions and twisted boundary conditions, we calculate the K meson semileptonic decay vector form factor at zero momentum transfer. The HISQ formulation is used for the valence quarks, while the sea quarks are simulated with the …