Thermodynamics of the N=2^* strongly coupled plasma

Abstract

Gauge/string duality is a potentially important framework for addressing the properties of the strongly coupled quark gluon plasma produced at RHIC. However, constructing an actual string theory dual to QCD has so far proven elusive. In this paper, we take a partial step towards exploring the QCD plasma by investigating the thermodynamics of a non-conformal system, namely the N=2^* theory, which is obtained as a mass deformation of the conformal N=4 gauge theory. We find that at temperatures of order the mass scale, the thermodynamics of the mass deformed plasma is surprisingly close to that of the conformal gauge theory plasma. This suggests that many properties of the quark gluon plasma at RHIC may in fact be well described by even relatively simple models such as that of the conformal N=4 plasma.

Figures (11)

• Figure 1: Altogether we obtained 3227 triplets $\{\xi,\rho_{10}(\xi),a_h(\xi)\}$. The left plot represents $\rho_{10}(\xi)$, and the right plot represents $a_h(\xi)$. The critical value of $\xi$ is at $\rho_{crit}\approx 0.03582(2)$. Red segments of the plots correspond to $\xi\in[0,\rho_{crit})$ such that $\rho_{10}(0)=a_h(0)=0$. Blue segments of the plots do not pass through the origin and correspond to $0<\xi <\rho_{crit}$. Black segments of the plots correspond to $\xi<0$.
• Figure 2: The left plot represents $\rho_{10}'(\xi)$ for both the red and the black segments of the left plot in Fig. \ref{['figb1']}. The right plot represents $a_h'(\xi)$ for both the red and the black segments of the right plot in Fig. \ref{['figb1']}. The green points on the right plot represent numerical verification of the first law of the thermodynamics, where $a_h'(\xi)$ must be canceled with an appropriate combination of $\{\xi,\rho_{10}(\xi),\rho'(\xi)\}$, see \ref{['1stb']}.
• Figure 3: The left plot represents $\rho_{10}'(\xi)$ for the blue segment of the left plot in Fig. \ref{['figb1']}. The right plot represents $a_h'(\xi)$ for the blue segment of the right plot in Fig. \ref{['figb1']}. The green points on the right plot represent numerical verification of the first law of the thermodynamics, where $a_h'(\xi)$ must be canceled with an appropriate combination of $\{\xi,\rho_{10}(\xi),\rho'(\xi)\}$, see \ref{['1stb']}.
• Figure 4: Altogether we obtained 2712 sets $\{\xi,\rho_{10}(\xi),\chi(\xi),a_h(\xi)\}$. The left plot represents $\rho_{10}(\xi)$, and the right plot represents $\chi_{10}(\xi)$.
• Figure 5: The left plot represents $a_h(\xi)$ for the supersymmetric mass deformation. The red/blue/black points on the right plot represent $\alpha_h'(\xi)$, $2(\rho_{10}-\xi \rho'_{10}(\xi))$ and $-(\chi_{10}(\xi)-\xi\chi_{10}'(\xi))$ correspondingly. The green points on the right plot represent numerical verification of the first law of the thermodynamics, see \ref{['1sts']}.