Continuum limit of hyperon vector coupling $f_1(0)$ from 2+1 flavor domain wall QCD

Abstract

We determine the hyperon vector couplings $f_1(0)$ for ${\Sigma }^{-}\to n{l}^{-}\overline{{\nu }_l}$ and ${\Xi }^0\to {\Sigma }^{+}{l}^{-}\overline{{\nu }_l}$ 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 $f_1(0)$ for $\Sigma \to N$ and $\Xi \to \Sigma$ beta-decays with an accuracy of less than one percent. We then find that lattice results of $f_1(0)$ combined with the best estimate of $|V_{us}|$ with imposing Cabibbo-Kobayashi-Maskawa (CKM) unitarity are slightly deviated from the experimental result of $|V_{us}{f}_1(0)|$ for the $\Sigma \to N$ beta-decay. This discrepancy can be attributed to an assumption made in the experimental analysis on $|V_{us}{f}_1(0)|$, where the induced second-class form factor $g_2$ is set to be zero regardless of broken SU(3) symmetry. We report on this matter and then estimate the possible value of $g_2(0)$, which is evaluated from the experimental decay rate with our lattice result of $f_1(0)$ under the first-row CKM-unitarity condition.

17 pages, 20 figures; v2: version published in PRD

References in corpus (11)

• Continuum Limit Physics from 2+1 Flavor Domain Wall QCD
• Model independent extraction of the proton charge radius from electron scattering
• Kl3 semileptonic form factor from 2+1 flavour lattice QCD
• Lattice study of flavor SU(3) breaking in hyperon beta decay
• First Lattice QCD Study of the Sigma -> n Axial and Vector Form Factors with SU(3) Breaking Corrections
• SU(3)-breaking corrections to the hyperon vector coupling $f_1(0)$ in covariant baryon chiral perturbation theory
• Nucleon form factors from quenched lattice QCD with domain wall fermions
• Chiral Corrections to the Hyperon Vector Form Factors
• Hyperon decay form factors in chiral perturbation theory
• Hyperon vector form factor from 2+1 flavor lattice QCD
• The baryon vector current in the combined chiral and 1/Nc expansions

Cited by in corpus (6)

• New physics in $s\to d$ semileptonic transitions: rare hyperon vs. kaon decays
• Hyperon semileptonic decays in QCD sum rules
• Feynman--Hellmann approach to transition matrix elements and quasi-degenerate energy states
• Effect of isoscalar and isovector scalar fields on baryon semileptonic decays in nuclear matter
• ${\Sigma }^{+}\to p{\ell }^{+}{\ell }^{-}$ decays within the standard model and beyond
• Baryons and baryoniums in the perspective of QCD sum rules