higher-order: 1

$|V_{us}|$ 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 …

One-loop Chiral Perturbation Theory with two fermion representations

We develop chiral perturbation theory for chirally broken theories with fermions in two different representations of the gauge group. Any such theory has a nonanomalous singlet U(1)A symmetry, yielding an additional Nambu-Goldstone boson when …

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 …

WW Scattering Parameters via Pseudoscalar Phase Shifts

Using domain-wall lattice simulations, we study pseudoscalar-pseudoscalar scattering in the maximal isospin channel for an SU(3) gauge theory with two and six fermion flavors in the fundamental representation. This calculation of the S-wave …