Properties of Proton in Diquark-Quark Model

Abstract

The properties of the proton has been investigated considering a proton as diquark-quark system. A model for diquark has been suggested in an analogy with the quasiparticle in a crystal lattice. The mass of the diquark obtained in the present model has been found to be in good agreement with other theoretical predictions. The binding energy of proton, compressibility and the excitation energy for the Roper Resonance have been estimated in the context of the proposed model. The results are found to be in agreement with the existing theoretical and experimental findings.The diquark is strongly correlated quark pair. It is now growing idea that the deeply bound diquarks are the building blocks of the mesons, baryon states and the exotics. The prediction of diquark is as old as the quark model and Gellmann has mentioned the possibility of diquark correlation in his original paper [1]. The regularities in the hadron spetroscopy, parton distribution functions, spin dependent structure function of hadrons etc. hints at the existence of diquark correlation [2][3][4][5][6]. At the experimental level it has been observed that the data for deep inelestic structure function for proton can be fitted in the frame work of the quark-diquark model of proton and it is predicted to be mostly in u [ud] state [7]. A number of works have been done towards the understanding of the structure of diquark. The possibility of forming quark-quark and quark-antiquark system by Instanton Induced Interaction (III) have been developed by Shuryak and Schafer et al. [8,9]. Betman et al. [10] have investigated formation of bound state of quark-quark or quark-antiquark systems due to instanton induced interaction and predicted that such bound state is formed inside the hadron as a bubble of the size of the instanton radius. In the context of discussing the exotic states of baryon Oka [11,12] has made a detailed study on the diquark correlation in the context of different models. It has been observed that the diquark picture in the framework of III model

On Some Properties of (Θ+) Excited States

“…In this present work we have estimated the mass for ground state, higher angular momentum states and the decay width of the positive parity pentaquark considering the diquark-diquarkantiquark configuration.The effective mass of the diquark has been estimated from the quasi particle approach [22]. Iwasaki and Takagi [10] have investigated the pentaquark higher states in the context of flux tube model.…”

“…The effective mass of the diquark [ud] gets modified [22] under the influence of the two types of forces and can be expressed as [20]:…”

“…In computing the mass we have used m D = 506 MeV [22], ms = 540 MeV, a = 0.219 GeV 2 [30]. With the values of r 0 from [10], the mass of pentaquark for higher angular momentum states have been estimated.…”

Dynamical Calculation of Θ+ Mass and Decay width in the Quark Model

“…The effective mass of the diquark gets modified [13] under the influence of the two types of forces and can be expressed as the following,…”

A study on P c * (4380) and P c * in the quasi particle diquark model

“…A number of models have been suggested for diquark [3][4][5][6][7][8][9][10]. In the present work we have studied the recently identified P * c states in diquark-diquark-antiquark configuration in the framework of quasiparticle model of diquark suggested by us [10][11][12].…”