Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userHeavy Quark Potential in a static and strong homogeneous magnetic field
103
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We have investigated the properties of quarkonia in a thermal QCD medium in the background of strong magnetic field. For that purpose, we employ the Schwinger proper-time quark propagator in the lowest Landau level to calculate the one-loop gluon self-energy, which in the sequel gives the the effective gluon propagator. As an artifact of strong magnetic field approximation ($eB>>T^2$ and $eB>>m^2$), the Debye mass for massless flavors is found to depend only on the magnetic field which is the dominant scale in comparison to the scales prevalent in the thermal medium. However, for physical quark masses, it depends on both magnetic field and temperature in a low temperature and high magnetic field but the temperature dependence is very meagre and becomes independent of temperature beyond a certain temperature and magnetic field. With the above mentioned ingredients, the potential between heavy quark ($Q$) and anti-quark ($bar Q$) is obtained in a hot QCD medium in the presence of strong magnetic field by correcting both short and long range components of the potential in real-time formalism. It is found that the long range part of the quarkonium potential is affected much more by magnetic field as compared to the short range part. This observation facilitates us to estimate the magnetic field beyond which the potential will be too weak to bind $Qbar Q$ together. For example, the $J/psi$ is dissociated at $eB sim$ 10 $m_pi^2$ and $Upsilon$ is dissociated at $eB sim$ 100 $m_pi^2$ whereas its excited states, $psi^prime$ and $Upsilon^prime$ are dissociated at smaller magnetic field $eB= m_pi^2$, $13 m_pi^2$, respectively.
rate research
Read More
We determine the hard-loop resummed propagator in an anisotropic QCD plasma in general covariant gauges and define a potential between heavy quarks from the Fourier transform of its static limit. We find that there is stronger attraction on distance scales on the order of the inverse Debye mass for quark pairs aligned along the direction of anisotropy than for transverse alignment.
Following the procedure and motivations developed by Richardson, Buchmuller and Tye, we derive the potential of static quarks consistent with both the three-loop running of QCD coupling constant under the two-loop perturbative matching of V and MS-bar schemes and the confinement regime at long distances. Implications for the heavy quark masses as well as the quarkonium spectra and leptonic widths are discussed.
We calculate the magnetic moments of heavy baryons with a single heavy quark in the bound-state approach. In this approach the heavy baryons is considered as a heavy meson bound in the field of a light baryon. The light baryon field is represented as a soliton excitation of the light pseudoscalar and vector meson fields. For these calculations we adopt a model that is both chirally invariant and consistent with the heavy quark spin symmetry. We gauge the model action with respect to photon field in order to extract the electromagnetic current operator and obtain the magnetic moments by computing pertinent matrix elements of this operator between the bound state wavefunctions. We compare our predictions for the magnetic moments with results of alternative approaches for the description of heavy baryon properties.
In this paper, we construct a simple model for the complex heavy quark potential which is defined through the Fourier transform of the static gluon propagator. Besides the hard thermal loop resummed contribution, the gluon propagator also includes a non-perturbative term induced by the dimension two gluon condensate. Within the framework of thermal field theory, the real and imaginary parts of the heavy quark potential are determined in a consistent way without resorting to any extra assumption as long as the exact form of the retarded/advanced gluon propagator is specified. The resulting potential model has the desired asymptotic behaviors and reproduces the data from lattice simulation reasonably well. By presenting a direct comparison with other complex potential models on the market, we find the one proposed in this work shows a significant improvement on the description of the lattice results, especially for the imaginary part of the potential, in a temperature region relevant to quarkonium studies.
We study the effect of strong magnetic field on competing chiral and diquark order parameters in a regime of moderately dense quark matter. The inter-dependence of the chiral and diquark condensates through nonperturbative quark mass and strong coupling effects is analyzed in a two-flavor Nambu-Jona-Lasinio (NJL) model. In the weak magnetic field limit, our results agree qualitatively with earlier zero-field studies in the literature that find a critical coupling ratio $G_D/G_Ssim 1.1$ below which chiral or superconducting order parameters appear almost exclusively. Above the critical ratio, there exists a significant mixed broken phase region where both gaps are non-zero. However, a strong magnetic field $Bgtrsim 10^{18}$ G disrupts this mixed broken phase region and changes a smooth crossover found in the weak-field case to a first-order transition for both gaps at almost the same critical density. Our results suggest that in the two-flavor approximation to moderately dense quark matter, strong magnetic field enhances the possibility of a mixed phase at high density, with implications for the structure, energetics and vibrational spectrum of neutron stars.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
