Exotic multi-quark states in the deconfined phase from gravity dual models

Abstract

In the deconfined phase of quark-gluon plasma, it seems that most of the quarks, antiquarks and gluons should be effectively free in the absence of the linear confining potential. However, the remaining Coulomb-type potential between quarks in the plasma could still be sufficiently strong that certain bound states, notably of heavy quarks such as J/ψ are stable even in the deconfined plasma up to a certain temperature. Baryons can also exist in the deconfined phase provided that the density is sufficiently large. We study three kinds of exotic multi-quark bound states in the deconfined phase of quarkgluon plasma from gravity dual models in addition to the normal baryon. They are k-baryon, (N +k)-baryon and a bound state of j mesons which we call "j-mesonance". Binding energies and screening lengths of these exotic states are studied and are found to have similar properties to those of mesons and baryons at the leading order. Phase diagram for the exotic nuclear phases is subsequently studied in the Sakai-Sugimoto model. Even though the exotics are less stable than normal baryons, in the region of high chemical potential and low temperature, they are more stable thermodynamically than the vacuum and chiral-symmetric quark-gluon plasma phases (χS-QGP). *

Magnetized domain walls in the deconfined Sakai-Sugimoto model at finite Baryon density

“…8 of Ref. [17]. For B > 0, dependence of u 0 on B affects the transition line accordingly as shown in Fig.…”

“…by using the boundary conditions a A 1 (u c ) = 0 and Eqn. (17) at u c . Additionally, there are two constraints which need to be satisfied,…”

“…The multiquark nuclear phase has been studied in Ref. [11,14,17] and found to be the most preferred phase for the dense deconfined nuclear matter under moderate external magnetic fields. The multiquark phase actually has certain mixture of the pion gradient as the source for the baryon density.…”

Magnetic phase diagram of dense holographic multiquarks in the quark-gluon plasma

“…[11] and extended to include multiquarks with colour charges in Ref. [10]. It has certain similarity to the conventional QCD phase diagram speculated from other approaches e.g.…”

“…If the coupling is still strong, bound states of quarks could form (see Ref. [5][6][7][8][9][10] for multiquark related studies). The phase diagram of the holographic nuclear matter in the SS model is studied in details in Ref.…”