X(3872): propagating in a dense medium

K Azizi,N Er

doi:10.1016/j.nuclphysb.2018.09.014

Abstract

In cold nuclear matter, the shifts in the mass and current-meson coupling as well the vector self energy of the exotic X(3872) are calculated using the diquark–antidiquark current within the framework of the in-medium two-point QCD sum rule. At the rest frame of the medium, the three momentum of the considered particle is fixed to remove the contributions of the particles with negative energy. In the calculations, we include the in-medium condensates of quark–quark, gluon–gluon and quark–gluon. It is observed that, the shift due to the nuclear matter is negative and is about 25% when the saturation density is used. Such shift is considerably large and comparable with the nucleon' mass shift due to the nuclear medium. The negative shift in the current-meson coupling due to nuclear matter is approximately 10%. At the saturation density, the vector self energy of the exotic X(3872) state is found to be Συ=1.31 GeV. It is shown that the mass, current-meson coupling and vector self energy of X(3872) strongly depend on the density of cold nuclear matter.

Highlights

In recent years, the new hadronic states such as mesonmeson, meson-baryon and baryon-baryon molecules, tetraquarks, pentaquarks, hybrids and glueballs have been in the focus of much attention
We find the average value of the vector self energy of X particle as Συ = 1.31 GeV at saturation density, ρsNat = 0.113
We used the interpolating current in a diquark-antidiquark form to investigate the spectroscopic parameters of the famous X(3872) tetraquark in the cold nuclear matter

Summary

INTRODUCTION

The new hadronic states such as mesonmeson, meson-baryon and baryon-baryon molecules, tetraquarks, pentaquarks, hybrids and glueballs have been in the focus of much attention. Investigation of the in-medium properties of exotic states, besides the standard hadrons, can play crusial role in the analysing of the results of the heavy-ion collision experiments Many experimental collaborations, such as PANDA, CBM at FAIR and NICA are planning to study the in-medium properties of hadrons including the newly discovered nonconventional states [40,41,42,43,44,45,46,47]. We are going to evaluate the spectroscopic parameters such as the mass, current-meson coupling constant and vector self energy of the exotic X(3872) at cold nuclear medium within the in-medium two-point QCD sum rule method and considering a diquark-antidiquark picture for this particle. To suppress the contributions of the higher states and continuum, a Borel transformation as well as continuum subtraction are applied to both sides of the obtained sum rules

Hadronic Representation

OPE Representation

NUMERICAL ANALYSES

Findings

CONCLUSION