Configuration entropy and stability of bottomonium radial excitations in a plasma with magnetic fields

Abstract

Heavy vector mesons produced in a heavy ion collision are important sources of information about the quark gluon plasma (QGP). For instance, the fraction of bottomonium states observed in a such a collision is altered by the dissociation effect caused by the plasma. So, it is very important to understand how the properties of the plasma, like temperature, density and the presence of background magnetic fields, affect the dissociation of bottomonium in the thermal medium. AdS/QCD holographic models provide a tool for investigating the properties of heavy mesons inside a thermal medium. The meson states are represented by quasinormal modes in a black hole geometry. In this work we calculate the quasinormal modes and the associated complex frequencies for the four lowest levels of radial excitation of bottomonium inside a plasma with a magnetic field background. We also calculate the differential configuration entropy (DCE) for all these states and investigate how the dissociation effect produced by the magnetic field is translated into a dependence of the DCE on the field. An interesting result obtained in this study is that the DCE increases with the radial excitation level. Also, a non trivial finding of this work is that the energy density associated with the bottomonium quasinormal modes present a singularity near the black hole horizon. However, as we show here, it is possible to separate the singular factor and define a square integrable quantity that provides the DCE for the bottomonium states.

Chaotic dynamics of a suspended string in a gravitational background with magnetic field

“…( 6)-( 8) and the corresponding one computed in Ref. [30,31,33], for r h = 1 and varying the magnetic field B. the metric, resulting from the different approximations in determining the solution of the Einstein equations, is in the function q. For larger values of the coordinate r the deviations are smaller.…”

“…In Fig. 1 the differences between the metric functions f (r), q(r) and h(r) in ( 6)-( 8) and the corresponding ones computed for low B in [30,31] and used in [33] are depicted setting r = 1.1 and varying B. The comparison shows that the largest deviation between the two expressions of Figure 1: For F one of the metric functions f (r = 1.1) (green line), q(r = 1.1) (red dashed line)…”

“…The deviations between ( 6)-( 8) and those in Refs. [30,31,33] are larger because in such references different conditions for q(r h ) and h(r h ) are imposed.…”

Nuclear configurational entropy and high energy hadron-hadron scattering reactions

“…The QCD theory of strong interactions is a gauge theory, wherein the Color Glass Condensate (CGC) approach is a strong and convenient tool to investigate the mechanism of high-energy processes. In this setup, the differential configurational entropy (DCE) techniques predict the crucial points that help to understand the massive experimental data obtained by different collaborative groups [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. At high energy regimes, the interesting and important information about various aspects of the reaction, for example, the total hadron-hadron or photon-hadron cross sections, can be derived by applying the nuclear DCE approach to nuclear systems at extreme conditions [18][19][20][21].…”