We have performed a dynamical calculation of the bound state problem of D0D*0 by considering the pion and sigma meson exchange potential. Our preliminary analysis disfavors the molecular interpretation of X(3872) if we use the experimental D*Dπ coupling constant g=0.59 and a reasonable cutoff around 1 GeV,which is the typical hadronic scale. In contrast,there probably exists a loosely bound S-wave BB* molecular state. Such a molecular state would be rather stable since its dominant decay mode is the radiative decay through B*→Bγ.
LIU Yan-rui1,LIU Xiang2,3,DENG Wei-zhen2 (1 Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China
Low-energy scattering of D ^＊＋ and D1^0 meson is studied using quenched lattice QCD with improved lattice actions on anisotropic lattices.The threshold scattering parameters,namely the scattering length a 0 and the effective range r 0,for the s-wave scattering in J P = 0 - channel are extracted： a 0 = 2.52（47） fm and r 0 = 0.7（1） fm.It is argued that,albeit the interaction between the two charmed mesons being attractive,it is unlikely that they can form a shallow bound state in this channel.Our calculation provides some useful information on the nature of the newly discovered resonance-like structure Z ＋ （4430） by the Belle Collaboration.
We analyze the left-right asymmetry in the semi-inclusive deep inelastic scattering （SIDIS） process using a method where no weighting function are used. Considering all flavor of quarks, we reanalyze the π±production and extend our calculation on the K± production. The predictions on HERMES, COMPASS and JLab kinematics with transversely polarized nucleon target are shown in this paper.
We report our investigation on the octet baryon spectrum in the nonrelativistic quark model by taking into account the two-gluon exchange effect. The calculated octet baryon masses agree better with the experimental data. It is also shown that the two-gluon exchange interactions bring a significant correction to the Gell-Mann-Okubo mass formula.
A new and simple statistical approach is performed to calculate the parton distribution functions （PDFs） of the nucleon in terms of light-front kinematic variables.Analytic expressions of x-dependent PDFs are obtained in the whole x region.And thereafter,we treat the temperature T as a parameter of the atomic number A to explain the nuclear EMC effect in the region x ∈ [0.2,0.7].We give the predictions of PDF ratios,and they are very different from those by other models,thus experiments aiming at measuring PDF ratios are suggested to provide a discrimination of different models.
The P-wave charm-strange mesons Ds0（2317） and Ds1（2460） lie below the DK and D＊K threshold respectively. They are extremely narrow because their strong decays violate the isospin symmetry. We study the possible heavy molecular states composed of a pair of excited charm strange mesons. As a byproduct, we also present the numerical results for the bottonium-like analogue.
The J/ψ hadronic decays provide good laboratory to search for the hybrid states with exotic quantum numbers. A full Partial Wave Analysis （PWA） is performed to the generated Monte Carlo J/ψ→ ρηπ data, based on the design of BESⅢ detector, to study the sensitivity of searching for a possible exotic state at BESⅢ.
Because the nucleon may be excited and transformed into a virtual A resonance easily, we consider the decuplet contribution to the parity-violating （PV） nucleon-nucleon interaction in the chiral effective field theory. The effective PV nucleon-nucleon potential is derived without introducing any unknown coupling constants.
We study the states π1(1600) and π1(2015) in the QCD sum rule. We classify the tetraquark currents of the quantum numbers IGJPC=1-1-+,and find that the flavor structure (3 6 )(6 3 ) is preferred when using a diquark-antidiquark construction. By using both the SVZ and finite energy sum rules,we obtain a mass around 1.6 and 2.0 GeV,for the states with the quark contents qq and qs,respectively. We also study their decay patterns.
