Related papers: Axial coupling constant in a magnetic background
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.
We compute the running of the cosmological constant and Newton's constant taking into account the effect of quantum fields with any spin between 0 and 2. We find that Newton's constant does not vary appreciably but the cosmological constant…
The weak decay as well as the strong nucleon coupling constants of the isoscalar axial vector meson $f_1 (1285)$ are estimated within the octet quark model. It is shown that the empirical value for the coupling of $\overline{s}s$ quarkonium…
The strong coupling constants $g_{{\Sigma_{Q}\Lambda_{Q}\pi}}$ ($Q=b$ and $c$) are studied in the framework of the light cone QCD sum rules using the most general form of the baryonic currents. The predicted coupling constants are used to…
In this article, we calculate the axial and the induced pseudoscalar form-factors $G_A(t=-Q^2)$ and $G_P(t=-Q^2)$ of the nucleons in the framework of the light-cone QCD sum-rules approach up to twist-6 three valence quark light-cone…
The coupling constants g$_{\rho\eta\gamma}$ and g$_{\omega\eta\gamma}$ are calculated using QCD sum rules method by studying the three point ${\rho\eta\gamma}$ and ${\omega\eta\gamma}$ correlation functions. A comparison of the results with…
We present a short summary for the calculations of the nucleon $\textit{isovector}$ form factors, which are relevant to improving the accuracy of the current neutrino oscillation experiments. The calculations are carried out with two of…
We compute the one-loop thermo-magnetic corrections to the self-coupling in a model where charged scalars interact also with a constant magnetic field. The calculation is motivated by the possibility that the critical temperature for the…
We study QCD finite energy sum rules (FESR) for the axial-vector current correlator in the presence of a magnetic field, in the weak field limit and at zero temperature. We find that the perturbative QCD as well as the hadronic contribution…
It is well established that the nucleon form factors can be related to Generalized Parton Distributions (GPDs) through sum-rules. On the other hand, GPDs can be expressed in terms of Parton Distribution Functions (PDFs) according to Diehl's…
We study the mass spectrum of light pseudoscalar and vector mesons in the presence of an external uniform magnetic field $\vec B$, considering the effects of the mixing with the axial vector meson sector. The analysis is performed within a…
Using a chirally invariant effective Lagrangian, we calculate the density and isospin dependences of the in-medium axial coupling, $g_A^*$, in spatially uniform matter present in core collapse supernovae and neutron stars. The quenching of…
We investigate the chiral properties of QCD in presence of a magnetic background field and in the low temperature regime, by lattice numerical simulations of N_f = 2 QCD. We adopt a standard staggered discretization, with a pion mass around…
Two new QCD sum rules for nucleon tensor charge are derived from a mixed correlator of spin-1/2 and spin-3/2 nucleon interpolating fields. These sum rules are analyzed along with a sum rule obtained from the usual correlator of a general…
The value of the proton singlet axial constant is estimated. It has been shown that the axial anomaly plays a crucial role in this calculation. Obtained result is sufficiently suppressed in comparison with the naively expected one. The…
The axial-vector form factor of the nucleons is considered in the framework of hard-wall model of holographic QCD. A new interaction term between the bulk gauge and matter fields was included into the interaction Lagrangian. We obtain the…
The coupling constant g_{rho sigma gamma} is determined from light cone QCD sum rules. A comparison of our result with the ones existing in literature is presented.
The decay of a massive pseudoscalar, scalar and U(1) boson into an electron-positron pair in the presence of strong electromagnetic backgrounds is calculated. Of particular interest is the constant-crossed-field limit, relevant for…
The coupling constant of the meson vertex $J/\psi D_s D_s$ is calculated using the three point correlation function within the QCD Sum Rule formalism. We have considered alternately mesons $J/\psi$ and $D_s$ off-shell together with…
It is shown that in the constituent quark model of Georgi-Manohar, the dispersion relation that leads to the Adler-Weisberger sum rule for the axial vector coupling $g_A$ requires a subtraction constant. This fact explains the discrepancy…