Ratio of kaon and pion leptonic decay constants with Nf=2+1+1 Wilson-clover twisted-mass fermions
| Autor: | Bartosz Kostrzewa, Martin Ueding, Giannis Koutsou, Constantia Alexandrou, Urs Wenger, Roberto Frezzotti, Francesco Sanfilippo, M. Garofalo, Jacob Finkenrath, Georg Bergner, Silvano Simula, Carsten Urbach, Simone Bacchio, P. Dimopoulos, P. Labus |
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| Rok vydání: | 2021 |
| Předmět: |
Quantum chromodynamics
Quark Physics Particle physics Chiral perturbation theory Unitarity 010308 nuclear & particles physics Computer Science::Information Retrieval High Energy Physics::Lattice High Energy Physics::Phenomenology Computer Science::Computation and Language (Computational Linguistics and Natural Language and Speech Processing) Particle Data Group Fermion 01 natural sciences Pion 0103 physical sciences High Energy Physics::Experiment 010306 general physics Pion decay constant |
| Zdroj: | Physical Review D. 104 |
| ISSN: | 2470-0029 2470-0010 |
| DOI: | 10.1103/physrevd.104.074520 |
| Popis: | We present a determination of the ratio of kaon and pion leptonic decay constants in isosymmetric QCD (ISOQCD), ${f}_{K}/{f}_{\ensuremath{\pi}}$, making use of the gauge ensembles produced by the Extended Twisted Mass Collaboration with ${N}_{f}=2+1+1$ flavors of Wilson-clover twisted-mass quarks, including configurations close to the physical point for all dynamical flavors. The simulations are carried out at three values of the lattice spacing ranging from $\ensuremath{\sim}0.068$ to $\ensuremath{\sim}0.092\text{ }\text{ }\mathrm{fm}$ with linear lattice size up to $L\ensuremath{\sim}5.5\text{ }\text{ }\mathrm{fm}$. The scale is set by the particle data group (PDG) value of the pion decay constant, ${f}_{\ensuremath{\pi}}^{\text{ISO}\mathrm{QCD}}=130.4(2)\text{ }\text{ }\mathrm{MeV}$, at the ISOQCD pion point, ${M}_{\ensuremath{\pi}}^{\text{ISO}\mathrm{QCD}}=135.0(2)\text{ }\text{ }\mathrm{MeV}$, obtaining for the gradient-flow scales the values ${w}_{0}=0.17383(63)\text{ }\text{ }\mathrm{fm}$, $\sqrt{{t}_{0}}=0.14436(61)\text{ }\text{ }\mathrm{fm}$ and ${t}_{0}/{w}_{0}=\phantom{\rule{0ex}{0ex}}0.11969(62)\text{ }\text{ }\mathrm{fm}$. The data are analyzed within the framework of SU(2) chiral perturbation theory without resorting to the use of renormalized quark masses. At the ISOQCD kaon point ${M}_{K}^{\text{ISO}\mathrm{QCD}}=494.2(4)\text{ }\text{ }\mathrm{MeV}$ we get $({f}_{K}/{f}_{\ensuremath{\pi}}{)}^{\text{ISO}\mathrm{QCD}}=1.1995(44)$, where the error includes both statistical and systematic uncertainties. Implications for the Cabibbo-Kobayashi-Maskawa matrix element $|{V}_{us}|$ and for the first-row Cabibbo-Kobayashi-Maskawa unitarity are discussed. |
| Databáze: | OpenAIRE |
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