Related papers: The Pion Mass Formula
A continuum approach to quark-antiquark bound-states is used to determine the electromagnetic form factors of pion-like mesons with masses $m_{0^-}/{\rm GeV}=0.14$, $0.47$, $0.69$, $0.83$ on a spacelike domain that extends to $Q^2 \lesssim…
We compute the strong coupling constant $g_{P^* P \pi}$, with $P$ and $P^*$ respectively pseudoscalar and vector heavy mesons by using the QCD sum rules approach. Our computation is based on the evaluation of the time ordered product of…
The influence of mesonic fluctuations on quantities in the Nambu-Jona-Lasinio model is examined in different approximation schemes: an expansion in powers of 1/N_c and an expansion up to one-meson loop in the effective action formalism. It…
We argue that the effective pion mass in nuclear matter obtained from chiral effective lagrangians is unique and does not depend on off-mass-shell extensions of the pion fields as e.g. the PCAC choice. The effective pion mass in isospin…
A one parameter, model confined-gluon propagator is employed in a phenomenological application of the Dyson-Schwinger and Bethe-Salpeter equations to the calculation of a range of $\pi$- and $\rho$-meson observables. Good agreement is…
The boson mass and the condensate in two dimensional QCD with $SU(N_c)$ colors are numerically evaluated with the Bogoliubov vacuum. It is found that the boson mass is finite at the massless limit, and it is well described by the…
QCD sum rules are used to compute the first few moments of the mesonic quark momentum. Transverse, longitudinal and mixed transverse-longitudinal components are examined. The transverse size of the pion is shown to be dictated by the gluon…
This work is driven by our curiosity towards some basic questions in QCD: how is the energy of a moving hadron partitioned among different gauge-invariant sectors in QCD Hamiltonian? How is the energy of an massless pion separated between…
In Monte Carlo simulations of N=1 supersymmetric Yang-Mills theory the mass of the unphysical adjoint pion, which is easily obtained numerically, is being used for the tuning to the limit of vanishing gluino mass. In this article we show…
We analyze the equal-time Bethe-Salpeter quark wave function of the pion obtained from a quenched lattice QCD calculation with delocalized quark interpolators. We find that the result agrees remarkably well with the predictions of the…
A model of mesons which is based on the QCD Hamiltonian in Coulomb gauge is presented. The model relies on a novel quasiparticle basis to improve the reliability of the Fock space expansion. It is also relativistic, yields chiral pions, and…
The relevance of the pion mass, provenient from a term which explicitely breaks chiral symmetry in the Lagrangian, for nucleon magnetic moment in the frame of the Skyrmion model in two different versions: the usual Skyrme model and a…
A "muon mass tree" is displayed that contains the excitation systematics for accurately reproducing the masses of the six Standard Model quarks (u,d,s,c,b,t); the heavy leptons; the proton; the phi, J/Psi and Upsilon vector meson thrshold…
The relationship between mesonic correlations and quantum condensates in the quark matter phase diagram is explored within a quantum field theoretical approach of the Nambu and Jona-Lasinio (NJL) type. Mean-field values in the scalar meson…
We present a $SU(3)_F$ meson mass formula from random phase approximation (RPA). Both the mesons of ground-state pseudoscalar octet and the ground-state vector octet are described quite well in this mass formula. We also estimate the…
We extend the investigation of the Generalized Parton Distribution for a charged pion within a fully covariant constituent quark model, in two respects: (i) calculating the tensor distribution and (ii) adding the treatment of the evolution,…
We present physics results from simulations of QCD using $N_f = 2$ dynamical Wilson twisted mass fermions at the physical value of the pion mass. These simulations were enabled by the addition of the clover term to the twisted mass quark…
We apply Bogolubov approach to QCD with two light quarks to demonstrate a spontaneous generation of an effective interaction, leading to the Nambu -- Jona-Lasinio model. The resulting theory contains two parameters: average low-energy value…
Effects of charge symmetry breaking associated with the $u$ and $d$ quark mass difference in the elastic form factors of the pion and kaon are presented. We use a confining version of the Nambu--Jona-Lasinio model. The pion and kaon are…
We investigate hadronic unquenching effects in light quarks and mesons. Within the non-perturbative continuum framework of Schwinger-Dyson and Bethe-Salpeter equations we quantify the strength of the back reaction of the pion onto the…