Related papers: Evidence for Magnetic Fields in Light Meson Spectr…
The strange form factors of the nucleon are studied in a two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. A comparison with the available experimental world data from the SAMPLE, PVA4, HAPPEX…
A model combining vector meson dominance, $\omega - \phi$ mixing and a kaon cloud contribution is used to estimate the strangeness vector form factors of the nucleon in the momentum range of the planned measurements at MIT-Bates and CEBAF.…
Within the Bethe-Salpeter framework, we present a computation of space-like electromagnetic form factors for pseudoscalar mesons, including light and heavy-light systems. Our approach employs a flavour-dependent variation of the standard…
Recent work by Philbin [1] has provided a Lagrangian theory that establishes a general method for the canonical quantization of the electromagnetic field in any dispersive, lossy, linear dielectric. Working from this theory, we extend the…
We study the relativistic quark-antiquark system embedded in magnetic field. The Hamiltonian containing confinement, one gluon exchange and spin-spin interaction is derived. We analytically follow the evolution of the lowest meson states as…
Recent models of spectral formation in magnetars called renewed attention on electron-photon scattering in the presence of ultra-strong magnetic fields. Investigations presented so far mainly focussed on mildly relativistic particles and…
The magnetic moments of the recently observed resonance $X_b(5568)$ by DO Collaboration and its partner with charm quark are calculated in the framework of the light cone QCD sum rules, by assuming that these resonances are represented as…
We analyse various $U(1)_{EM}$ form factors of mesons at strong coupling in an $\mathcal{N}=2$ flavored version of $\mathcal{N}=4$ $SYM$ which becomes conformal in the UV. The quark mass breaks the conformal symmetry in the IR and generates…
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 derive the electric and magnetic form factors of the neutron in the framework of a relativistic constituent quark model. Our parameter free prediction agrees well with a recent, accurate measurement. The relativistic features of the…
We derive an explicit analytical expression for the magnetic dipole moment of the rho meson, mu_rho, in a relativistic constituent-quark model. We adopt our relativistic approach to composite systems, modified instant-form (mIF)…
The finding of a new formulation of the magnetization vector of a quantum system interacting with a static uniform magnetic field\cite{Selenu1} is reported. There a gauge invariant form of its divergence is shown being expressed as a…
We investigate the electromagnetic form factors of the (rho) meson in light cone QCD sum rules. We find that the ratio of the magnetic and charge form factors is larger than two at all values of Q^2, (Q^2 >= 0.5 GeV^2). The values of the…
Weak magnetic field induced corrections to effective coupling constants describing light vector mesons mixings and vector meson dominance (VMD) are derived. The magnetic field must be weak with respect to an effective quark mass $M^*$ such…
The electromagnetic form factors of the nucleon are calculated in an extended chiral constituent-quark model where the effective interaction is described by the exchange of pseudoscalar, vector, and scalar mesons. Two-body current-density…
In this letter, we propose that a proper constituent gluon mass $m_g$=450 MeV can be applied to identify the hybrids composed of quarks and gluons. By investigating the spectra and decay widths of the light hybrids $(q\bar{q}g)$ with…
We describe a symmetry-preserving calculation of the meson spectrum, which combines a description of pion properties with reasonable estimates of the masses of heavier light-quark mesons, including axial-vector states. The kernels used in…
Based on the expectation that constituent quark model may capture right physics in the large N limit, we point out that orbital angular momentum of the quark-antiquark pair inside light mesons of low spins in the constituent quark model may…
The elastic and transition electromagnetic form factors of mesons are investigated within a light-front constituent quark model. The general formulae for the space-like matrix elements of the one-body component of the electromagnetic…
Third QED order hadronic light-by-light (LBL) contributions $a_\mu^{LBL}(M)$ to the anomalous magnetic moment of the muon $a_\mu^{had}$ from the pole terms of scalar $\sigma$, $a_0(980)$ and pseudoscalar $\pi^0$, $\eta$, $\eta '$ mesons (M)…