Eur. Phys. J. A (2011) 47: 110
https://doi.org/10.1140/epja/i2011-11110-8

Regular Article - Theoretical Physics

Thermal QCD sum rules study of vector charmonium and bottomonium states

¹ Department of Physics, Kocaeli University, 41380, Izmit, Turkey
² Physics Division, Faculty of Arts and Sciences, Doğuş University, Acıbadem-Kadıköy, 34722, Istanbul, Turkey

^* e-mail: elsen@kocaeli.edu.tr

Received: 4 May 2011
Revised: 19 July 2011
Accepted: 5 September 2011
Published online: 23 September 2011

Abstract

We calculate the masses and leptonic decay constants of the heavy vector quarkonia, J/ψ and ϒ mesons at finite temperature. In particular, considering the thermal spectral density as well as additional operators coming up at finite temperature, the thermal QCD sum rules are acquired. Our numerical calculations demonstrate that the masses and decay constants are insensitive to the variation of temperature up to T ≅ 100 MeV, however after this point, they start to fall altering the temperature. At deconfinement temperature, the decay constants attain roughly to 45% of their vacuum values, while the masses are diminished about 12%, and 2.5% for J/ψ and ϒ states, respectively. The obtained results at zero temperature are in good consistency with the existing experimental data as well as predictions of the other nonperturbative models.