Continuum limit of hyperon vector coupling f1(0) from 2+1 flavor domain wall QCD

2017/08/31 by Shoichi Sasaki
Physics and Astronomy · #Atomic and Subatomic Physics Research #Baryon #Hyperon #Lattice (music) #Lepton #Meson #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Pseudovector #Quantum Chromodynamics and Particle Interactions #Semileptonic decay #hep-lat #hep-ph

paper · pdf · doi:10.1103/physrevd.96.074509

published as Phys. Rev. D 96, 074509 (2017) · 17 pages, 20 figures; v2: version published in PRD

openalex created_date 2017/08/31 · openalex publication_date 2017/10/25 · arxiv created 2017/10/26 · arxiv updated 2017/10/27 · openalex updated_date 2026/08/05

Abstract

We determine the hyperon vector couplings f₁(0) for \mathrm\ensuremathΣ^\ensuremath-\ensuremath→nl^\ensuremath-\ensuremathν_l and \mathrm\ensuremathΞ⁰\ensuremath→\mathrm\ensuremathΣ⁺l^\ensuremath-\ensuremathν_l semileptonic decays in the continuum limit with (2+1)-flavors of dynamical domain-wall fermions, using the Iwasaki gauge action at two different lattice spacings of a=0.114(2) and 0.086(2) fm. A theoretical estimation of flavor SU(3)-breaking effect on the vector coupling is required to extract V_us from the experimental rate of hyperon beta decays. We obtain the vector couplings f₁(0) for \mathrm\ensuremathΣ\ensuremath→N and \mathrm\ensuremathΞ\ensuremath→\mathrm\ensuremathΣ beta-decays with an accuracy of less than one percent. We then find that lattice results of f₁(0) combined with the best estimate of |V_us| with imposing Cabibbo-Kobayashi-Maskawa (CKM) unitarity are slightly deviated from the experimental result of |V_usf₁(0)| for the \mathrm\ensuremathΣ\ensuremath→N beta-decay. This discrepancy can be attributed to an assumption made in the experimental analysis on |V_usf₁(0)|, where the induced second-class form factor g₂ is set to be zero regardless of broken SU(3) symmetry. We report on this matter and then estimate the possible value of g₂(0), which is evaluated from the experimental decay rate with our lattice result of f₁(0) under the first-row CKM-unitarity condition.

Citations

• Lattice QCD calculation ofB¯→Dlν¯decay form factors at zero recoil
• Nucleon form factors from quenched lattice QCD with domain wall fermions
• The static approximation of heavy-light quark systems. A detailed lattice study
• Model-independent extraction of |Vcb| using dispersion relations
• SU(3)symmetry breaking in hyperon semileptonic decays
• Nucleon form factors with2+1flavor dynamical domain-wall fermions
• First lattice QCD study of the Σ−→n axial and vector form factors with SU(3) breaking corrections
• Hyperon Physics from Lattice QCD
• SEMILEPTONIC HYPERON DECAYS
• Review of Multibody Charm Analyses