相关论文: Power Corrections and the Gaussian Form of the Mes…
We present a numerical pilot study of the meson correlation functions in the epsilon-regime of chiral perturbation theory. Based on simulations with overlap fermions we measured the axial and pseudo-scalar correlation functions, and we…
We use the simple instanton motivated Nambu Jona-Lasinio - type model to calculate a twist 3 pseudoscalar pion light cone wave function. Using normalisation condition for this wave function we calculate the quark condensate and also the…
We consider the bremsstrahlung energy loss of high energy partons moving in the quark-gluon plasma, at weak coupling. We show that the rates for these processes receive large O(g) corrections from classical (nonabelian) plasma physics…
The form factors of weak decays of the B meson to orbitally excited scalar, axial vector and tensor light mesons are calculated in the framework of the QCD-motivated relativistic quark model based on the quasipotential approach.…
We compute a light front wave function for heavy vector mesons based on long distance matrix elements constrained by decay width analyses in the Non Relativistic QCD framework. Our approach provides a systematic expansion of the wave…
In this paper we calculate the power corrections to the pion transition form factor within the framework of perturbative QCD approach on the basis of $k_T$ factorization. The power suppressed contributions from higher twist pion wave…
This letter is an investigation of the pion form factor utilizing recently developed effective field theory techniques. The primary results reported are: Both the transition and electromagnetic form factors are corrected at order…
The standard electroweak theory is tested at non-trivial quantum correction level through $\alpha$, $G_F$ and the latest data of the weak-boson masses. The improved-Born approximation and the non-decoupling top-quark effects are studied…
In this paper, we study the internal structure of light pseudoscalar mesons using spin improved power-law wave functions. We choose the pion and the kaon for our work. We use the standard quark-quark correlation functions to calculate the…
The electromagnetic form factors of light and heavy pseudoscalar mesons are calculated within two covariant constituent-quark models, a light-front and a dispersion relation approach. We investigate the details and physical origins of the…
We discuss power corrections to infrared safe cross sections and event shapes, and identify a nonperturbative function that governs 1/Q corrections to these quantities.
Quantum power corrections to the gravitational spin-orbit and spin-spin interactions, as well as to the Lense-Thirring effect, were found for particles of spin 1/2. These corrections arise from diagrams of second order in Newton…
We calculate the lowest-order non-linear contributions to the power spectrum, two-point correlation function, and smoothed variance of the density field, for Gaussian initial conditions and scale-free initial power spectra, $P(k) \sim k^n$.…
We present a detailed evaluation of the total semileptonic B meson width in terms of |V_{cb}| and heavy quark parameters (quark masses and the expectation values of local heavy quark operators). Special attention is given to perturbative…
The meson-photon transition form factors $\gamma\gamma^*\to P$ ($P$ stands for $\pi$, $\eta$ and $\eta'$) provide strong constraints on the distribution amplitudes of the pseudoscalar mesons. In this paper, these transition form factors are…
We investigate the $B$ and $D$ mesons in the relativistic quark model by applying the variational method with the Gaussian wave function. We calculate the Fermi momentum parameter $p_{_F}$, and obtain $p_{_F} = 0.50 \sim 0.54$ GeV, which is…
Semileptonic heavy -> heavy and heavy -> light meson transitions are studied as a phenomenological application of a heavy-quark limit of Dyson-Schwinger equations. Employing two parameters: E, the difference between the mass of the heavy…
We use the vacuum expectation value of a Wegner-Wilson loop representing a fast moving quark-antiquark pair to derive the light cone Hamiltonian for a $q\bar q$ meson. We solve the corresponding Schr\"odinger equation for various trial wave…
In this communication we discuss few topics related with modern experimental data on the physics of light pseudoscalar mesons. It includes the contribution of the pseudoscalar mesons to the muon anomalous magnetic moment (AMM), $g-2$, the…
We compute the $\mathcal{O}(k^2)$ terms (power corrections) of the photon polarization tensor in a hot and dense medium of particles with a small but finite mass, i.e., $0< m\ll T, \mu$. We perform our calculations within the hard thermal…