Spectral properties of $ρ$ meson in a magnetic field

We calculate the rho meson mass in a weak magnetic field using effective $\rho\pi\pi$ interaction. It is seen that both $\rho^0$ and $\rho^\pm$ masses decrease with the magnetic field in vacuum. $\rho$ meson dispersion relation has been calculated and shown to be different for $\rho^0$ and $\rho^\pm$. We also calculate the $\rho\pi\pi$ decay width and spectral functions of $\rho^0$ and $\rho^\pm$. The width is seen to decrease with $eB$ and the spectral functions become narrower.


Similar Publications

Magnetic monopoles, if they exist, would be produced amply in strong magnetic fields and high temperatures via the thermal Schwinger process. Such circumstances arise in heavy ion collisions and in neutron stars, both of which imply lower bounds on the mass of possible magnetic monopoles. In showing this, we construct the cross section for pair production of magnetic monopoles in heavy ion collisions, which indicates that they are particularly promising for experimental searches such as MoEDAL. Read More


We present evidence that the undularity and emissivity that often appear in local DPPs arising from coupling to inelastic or reaction channels can be attributed to $l$-dependence of the underlying non-local and $l$-dependent DPP. The $l$-independent $S$-matrix equivalent potentials of phenomenological $l$-dependent potentials exhibit qualitatively similar undulatory properties. It is also shown that $l$-dependent potentials based on smooth Woods-Saxon forms also have undulatory $l$-independent equivalents, including emissive regions. Read More


The integrated cross sections of high-energy $e^+e^-$ electroproduction by an electron in an atomic field is studied. Importance of various contributions to these cross sections is discussed. It is shown that the Coulomb corrections are very important both for the differential cross section and for the integrated cross sections even for moderate values of the atomic charge number. Read More


Motivated by the precise measurement of the $1S$ level shift of kaonic hydrogen, we perform accurate three-body calculations for the spectrum of kaonic deuterium using a realistic antikaon-nucleon ($KN$) interaction. In order to describe both short- and long-range behavior of the kaonic atomic states, we solve the three-body Schr\"odinger equation with a superposition of a large number of correlated Gaussian basis functions covering distances up to several hundreds of fm. Transition energies between $1S$, $2P$ and $2S$ states are determined with high precision. Read More


Recently we have proved the factorization of NRQCD S-wave heavy quarkonium production at all orders in coupling constant. In this paper we extend this to prove the factorization of infrared divergences in $\chi_{cJ}$ production from color singlet $c{\bar c}$ pair in non-equilibrium QCD at RHIC and LHC at all orders in coupling constant. This can be relevant to study the quark-gluon plasma at RHIC and LHC. Read More


$\phi$-meson--nucleus bound state energies and absorption widths are calculated for seven selected nuclei by solving the Klein-Gordon equation with complex optical potentials. Essential input for the calculations, namely the medium-modified $K$ and $\overline{K}$ meson masses, as well as the density distributions in nuclei, are obtained from the quark-meson coupling model. The attractive potential for the $\phi$-meson in the nuclear medium originates from the in-medium enhanced $K\overline{K}$ loop in the $\phi$-meson self-energy. Read More


We analyze the peripheral structure of the nucleon-nucleon interaction below pion production threshold. To this end we transform the scattering matrix into the impact parameter representation, by analyzing the scaled phase shifts $(L+1/2) \delta_{JLS} (p)$ and the scaled mixing parameters $(L+1/2)\epsilon_{JLS}$ in terms of the impact parameter $b=(L+1/2)/p$. According to the eikonal approximation at large angular momentum $L$ these functions should become an universal function of $b$, {\it independent} on $L$. Read More


We consider a non-ideal hot pion gas with the dynamically fixed number of particles in the model with the $\lambda\phi^4$ interaction. The effective Lagrangian for the description of such a system is obtained after dropping the terms responsible for the change of the total particle number. Reactions $\pi^+\pi^-\leftrightarrow\pi^0\pi^0$, which determine the isospin balance of the medium, are permitted. Read More


It is a common problem in lattice QCD calculations of hadron masses with annihilation channels that the signal falls off in time while the noise remains constant. In addition, the disconnected insertion calculation in the three-point function and the calculation of the neutron electric dipole moment with the $\theta$ terms suffer from a noise due to the $\sqrt{V}$ fluctuation. We identify these problems to have the same origin and the $\sqrt{V}$ problem can be resolved by utilizing the cluster decomposition principle. Read More


In this Letter I argue that the Surrogate Method, used to extract the fast neutron capture cross section on actinide target nuclei, which has important practical application for the next generation of breeder reactors, and the Trojan Horse Method employed to extract reactions of importance to nuclear astrophysics, have a common foundation, the Inclusive Non-Elastic Breakup (INEB)Theory. Whereas the Surrogate Method relies on the premise that the extracted neutron cross section in a (d,p) reaction is predominantly a compound nucleus one, the Trojan Horse Method, assumes a predominantly direct process for the secondary reaction induced by the surrogate fragment. In general, both methods contain both direct and compound contributions, and I show how theses seemingly distinct methods are in fact the same but at different energies and different kinematic regions. Read More