相关论文: The Weak Parity-Violating Pion-Nucleon Coupling

Quantum fluctuations in QCD influence nucleon structure and interactions, with pion production serving as a key probe of chiral dynamics. In this study, we present a lattice QCD calculation of multipole amplitudes at threshold, related to…

We complete our derivation of upper limits on the CP violating $\eta\pi\pi$ and $\eta'\pi\pi$ couplings from an analysis of their two-loop contributions to the neutron electric dipole moment (nEDM). We use a phenomenological Lagrangian…

Nuclear parity violation is studied with polarized neutrons in the photodisintegration of the deuteron at low energies. A pionless effective field theory with di-baryon fields is used for the investigation. Hadronic weak interactions are…

Neutron spin rotation is expected from quark-quark weak interactions in the Standard Model, which induce weak interactions among nucleons that violate parity. We present the results from an experiment searching for the effect of parity…

The electric dipole moments of nucleons (NEDM, d_N) are calculated using the method of QCD sum rules. Our calculations are based on the parity and time reversal violating parameter $\thetabar$ in QCD and establish a functional dependence of…

Parity-violating elastic electron-nucleon scattering at low momentum transfer allows one to access the nucleon's weak charge, the vector coupling of the $Z$-boson to the nucleon. In the Standard Model and at tree level, the weak charge of…

We study the neutron electric dipole moment in the presence of the CP-violating operators up to the dimension five in terms of the QCD sum rules. It is found that the OPE calculation is robust when exploiting a particular interpolating…

We revisit the analysis of the improved ladder Schwinger-Dyson (SD) equation for the dynamical chiral symmetry breaking in QCD with emphasizing the importance of the scale ambiguity. Previous calculation done so far naively used one-loop…

The coupling constant of g_phi-pi-gamma decay is calculated in the method of QCD sum rules. A comparison of our prediction on the coupling constant with the result obtained from analysis of the experimental data is performed.

I start by reviewing existing $\vec{p}p$ measurements with particular emphasis on the recent 221 MeV $\vec{p}p$ measurement at TRIUMF which permitted the weak meson-nucleon coupling constants $h^{pp}_\rho$ and $h^{pp}_\omega$ to be…

Standard QCD sum-rule analyses of the nucleon mass give results that are inconsistent with chiral perturbation theory due to an overly simple continuum ansatz on the phenomenological side of the sum rule. We show that a careful treatment of…

We interpret the results of searches for strongly interacting massive particles to place absolute lower limits on R-parity-violating couplings for squarks with mass (m_\tilde{q}) below 100 GeV. Recent searches for anomalous isotopes require…

We consider CP violating effects in the decays $\tau\rightarrow (3\pi)\nu_\tau$ where both the ${\rm J}^{\rm P}=1^+$ resonance, $a_1$, and ${\rm J}^{\rm P}=0^-$ resonance, $\pi^\prime$, can contribute. The interference between the $a_1$ and…

Using the correlation function of the axial vector mesons, we present a QCD sum rule calculation for the decay constants f_pi and f_K. Our calculations are only weakly dependent on the SU(3) breaking-parameter for the QCD vacuum and give…

Recent ALEPH/OPAL data on the V-A spectral functions from hadronic tau decays are used for fixing the QCD continuum threshold at which the first and second Weinberg sum rules should be satisfied in the chiral limit, and for predicting the…

From the recent measurement of parity nonconservation (PNC) in the Cs atom we have extracted the constant of the nuclear spin dependent electron-nucleon PNC interaction, $\kappa = 0.442 (63)$; the anapole moment constant, $\kappa_a = 0.364…

Pion production in nuclear collisions at the SPS is investigated with the aim to search, in a restricted domain of the phase diagram, for power-laws in the behavior of correlations which are compatible with critical QCD. We have analyzed…

We investigate the possibility of parity being spontaneously violated in QCD at finite baryon density and temperature. The analysis is done for an idealized homogeneous and infinite nuclear matter where the influence of density can be…

Firstly, we use the recent ALEPH/OPAL data on the V-A spectral functions for fixing the continuum threshold with which the first and second Weinberg sum rules should be satisfied in the chiral limit. Then, we predict the values of the…

Using QCD sum rules, we compute the diagonal meson-baryon couplings, $\pi NN$, $\eta NN$, $\pi \Xi\Xi$, $\eta \Xi\Xi$, $\pi \Sigma \Sigma$ and $\eta \Sigma \Sigma$, from the baryon-baryon correlation function with a meson, $i\int d^4x…