相关论文: Nucleon axial charge and pion decay constant from …
We present state-of-the-art results from a lattice QCD calculation of the nucleon axial coupling, $g_A$, using M\"obius Domain-Wall fermions solved on the dynamical $N_f = 2 + 1 + 1$ HISQ ensembles after they are smeared using the…
As increased statistics and new ensembles with light pions have become available within the CLS effort, we complete previous work by inspecting the chiral behaviour of the pion decay constant. We discuss the validity of Chiral Perturbation…
We compute the nucleon axial and pseudoscalar form factors using three $N_f=$2+1+1 twisted mass fermion ensembles with all quark masses tuned to approximately their physical values. The values of the lattice spacings of these three physical…
We present a lattice QCD study of the neutrinoless double beta decay involving light sterile neutrinos. The calculation is performed at physical pion mass using five gauge ensembles generated with the $2+1$-flavor domain wall fermions. We…
The latest $\pi N$ elastic scattering data are re-analysed to determine the coupling constant $g_c$ of the charged pion, using the dispersion relation for the invariant amplitude $B^{(+)}$. Depending on the choice of data-base, values…
We present the pion mass and decay constant using the overlap fermion valence on domain wall (DW) fermion sea at several lattice spacings. The mixed action effect in the lattice calculation is also studied, and the result suggests that the…
A global fit to the shape of the first QCD Laplace sum rule exhibiting sensitivity to pion-resonance [$\Pi (1300)$] parameters is performed, leading to predictions for the pion-resonance mass and decay constant. This fit leads to…
We present a quenched lattice calculation of the nucleon isovector vector and axial-vector charges gV and gA. The chiral symmetry of domain wall fermions makes the calculation of the nucleon axial charge particularly easy since the…
We study lattice QCD determinations of the pion mass and decay constant by means of chiral perturbation theory (ChPT). The lattice data are obtained from large scale simulations with N_f=2 flavours of twisted mass fermions at maximal twist.…
The nucleon axial coupling, $g_A$, is a fundamental property of protons and neutrons, dictating the strength with which the weak axial current of the Standard Model couples to nucleons, and hence, the lifetime of a free neutron. The…
We investigate the pion weak decay constant (F_pi) and pion mass (m_pi) at finite density within the framework of the nonlocal chiral quark model from the instanton vacuum with the finite quark-number chemical potential (mu) taken into…
We present a lattice QCD calculation of the nucleon electric polarizabilities at the physical pion mass. Our findings reveal the substantial contributions of the $N\pi$ states to these polarizabilities. Without considering these…
I present an overview of the calculations of the isovector axial vector form factor of the nucleon, $G_A(Q^2)$, using lattice QCD. Based on a comparison of results from various collaborations, a case is made that lattice results are now…
Our previous calculations of the sea- and valence-quark mass dependence of the pseudoscalar meson masses and decay constants is repeated on a 16^3x32 lattice which allows for a better determination of the quantities in question. The…
Previous extrapolations of lattice QCD results for the nucleon mass to the physically relevant region of small quark masses, using chiral effective field theory, are extended and expanded in several directions. A detailed error analysis is…
We determine the masses, the singlet and octet decay constants as well as the anomalous matrix elements of the $\eta$ and $\eta^\prime$ mesons in $N_f=2+1$ QCD\@. The results are obtained using twenty-one CLS ensembles of non-perturbatively…
We study relationship between the physical quantities that characterize pion-nucleon and nucleon-nucleon interaction on the basis of the fact that nuclear forces in the nucleon-nucleon system at low energies are mainly determined by the…
We review the theory that predicts that the decay constant of the excited light pseudo-scalar mesons are suppressed in the chiral limit relative to the pion decay constant. We compute the decay constant of the first excited pion…
We determine the axial, scalar and tensor isovector charges of the nucleon, sigma and cascade baryons as well as the difference between the up and down quark masses, $m_u-m_d$. We employ gauge ensembles with $N_f=2+1$ non-perturbatively…
Neutrinoless double beta decay, if detected, would prove that neutrinos are Majorana fermions and provide the direct evidence for lepton number violation. If such decay would exist in nature, then $\pi^-\pi^-\to ee$ and $\pi^-\to\pi^+ ee$…