Low-lyingS-wave andP-wave dibaryons in a nodal structure analysis

Abstract

The inherent nodal surface structure analysis approach is proposed for the sixquark clusters with u, d and s quarks. The wave-functions of the six-quark clusters are classified, and the contribution of the hidden-color channels are discussed.The quantum numbers and configurations of the wave-functions of the low-lying dibaryons are obtained. The states [ΩΩ] and the hidden-color channel ones with the same quantum numbers are proposed to be the candidates of experimentally observable dibaryons.It has been known that quark degrees of freedom are essential to describe properties of hadrons and the quantum chromodynamics(QCD) is the underlying theory for strong interaction. One of the current issues in this field involves the attempt to derive the shortrange part of the nucleon-nucleon interaction from the quark-gluon degrees of freedom.Unfortunately, it is now very difficult to make quantitative predictions with QCD at low and intermediate energy region. Therefore various phenomenological models based on the QCD assumptions, such as bag models[1], cluster model [2] have been developed.With the MIT bag model, a dibaryon, namely the H particle, was predicted by Jaffe in the later of 1970's [3]. Thereafter many attempts have been made to search for dibaryons in both theory and experiment, because it is an appropriate place to investigate the quark behavior in short distance and to explore the exotic states of QCD. On the theoretical side, almost all QCD inspired models (see for example Refs.[4,5,6,7,8,9]), even the QCD sum rules[10] and lattice QCD [11] predict that there exist dibaryon states. However, no dibaryon state except for the deuteron has been well established in experiment up to now. On the other hand, the theoretical predictions are quite far away from each other, since different approaches take different models and interactions (at least the interaction strength).After Jaffe predicted the existence of the H particle(strangeness s = −2, J P = 0 + ) as a color-singlet multi-quark system(q m q n , n + m > 3), Harvey developed a method in cluster model [12], with which all the antisymmetric six-quark states with definite orbital and isospin-spin symmetries were classified. Meanwhile, many hidden-color channel states which can not be represented in terms of free baryons were found. Unfortunately, the constituents Harvey considered include only u and d quarks. In other words, the strangeness of the system has not yet been taken into account. However, more and more evidences proved that the system with non-zero strangeness may be more stable to exist as a dibaryon(see for example Refs.[6,8,9,13,14]). It is then necessary to extend Harvey's framework to include s quarks and get a complete result.Along the way of the non-relativistic QCD, the concept of wave-function can be implemented to describe many-quark states, and embodied in the non-relativistic quark model [12,15]. On the other hand, it has been known that analyzing the symmetric property and the inherent nodal surface [16,17,18] is a quite powerful approac...

Solid Quark Stars?

“…Newborn strange stars could thus be solidified soon after supernova. The nature of this kind solid quark matter may depend on the quark cluster structures (Liu, Li, & Bao 2003) as well.…”

Effect of isospin-dependent cross-section on fragment production in the collision of charge asymmetric nuclei

“…These results are in similar lines and it also indicates that even binary phenomena like fission will also be insensitive towards isospin dependence of the dynamics [2]. Recently theoretical studies on the high density symmetry energy have been started by investigating heavy ion collisions of asymmetric systems [3,4]. Comparisons of collisions of neutron-rich to that of neutron-deficient systems provide a means of probing the asymmetry term experimentally [5][6][7].…”

P-wave two-particle bound and scattering states in a finite volume including QED

“…Pairwise interesting are recent studies on proton-ptoton collisions, which revealed the presence of intermediate P-wave ΔN states with spin 0 and 2 at 2.197(8) and 2.201 (5) GeV respectively, see ref [96]. Although these states are not classified as dibaryons [97] because of their large decay width (Γ 100 MeV) [96,98], an attractive force appears to lower the expected energy of the Δ − N system by ≈ 30 MeV. Additionally, loosely bound binary compounds of hadrons appearing in the vicinity of a P-wave strong decay threshold are not forbidden by the theory of hadronic molecules [99].…”

“…, (97) where D(E * ) is the strong P-wave coupling constant in presence of attractive electrostatic interaction and the matrix j C is, now, given by…”