Charmonium spectra at finite temperature from QCD sum rules with the maximum entropy method

Area of Science:

• Quantum Chromodynamics (QCD)
• High-Energy Nuclear Physics
• Hadron Spectroscopy

Background:

• Charmonium states are crucial probes of the quark-gluon plasma.
• Understanding their behavior at finite temperatures is key to characterizing the deconfined phase.

Purpose of the Study:

• To investigate the temperature dependence of charmonium spectral functions.
• To determine the fate of J/ψ and η(c) mesons in the hot and dense medium.

Main Methods:

• Application of QCD sum rules.
• Incorporation of the maximum entropy method for spectral function reconstruction.
• Analysis at temperatures approaching and exceeding the deconfinement temperature (T(c)).

Main Results:

• J/ψ and η(c) mesons exhibit distinct peaks in spectral functions below T(c).
• These peaks significantly diminish and merge into the continuum between 1.0T(c) and 1.1T(c).
• The spectral functions indicate a rapid dissolution of charmonium states.

Conclusions:

• Charmonium states like J/ψ and η(c) are not robust in the early stages of the quark-gluon plasma.
• Their disappearance suggests significant modification or melting in the deconfined environment.