分类: 物理学 >> 核物理学 提交时间: 2016-09-14
摘要: We investigate the neutral hidden charm pentaquark states P0c(4380) and P0c(4450) in π−p→J/ψnreaction within an effective Lagrangian approach. The background contributions for the process mainly come from t-channel π and ρ meson exchanges. The contributions of P0c(4380) and P0c(4450) states give clear peak structures in the magnitude of 1 μb at center of mass energy 4.38 GeV and 4.45 GeV in the total cross sections. Hence, this reaction may provide a new good platform to search for neutral Pc states. It is expected that our estimated total cross sections together with the angular distributions can be tested by future experiments at J-PARC.
分类: 物理学 >> 核物理学 提交时间: 2016-09-14
摘要: We study the radiative decays of the Zc(3900)0 in a hadronic molecule picture, where the Zc(3900) is treated as a DD¯∗+c.c hadronic molecule. The partial widths of Γ(Zc(3900)0→γηc(2S)) and Γ(Zc(3900)0→γχc0) are predicted to be of order 10 keV and the cross sections for σ(e+e−→π0Zc(3900)→π0γηc(2S)) and σ(e+e−→π0Zc(3900)→π0γχc0) are of order 0.1 pb at 4.23 GeV, which may be accessible for the BESIII and forthcoming BelleII.
分类: 物理学 >> 核物理学 提交时间: 2016-09-13
摘要: We report on a theoretical study of the π−p→D−D0p reaction near threshold within an effective Lagrangian approach. The production process is described by t channel D∗0 meson exchange, s-channel nucleon pole, and u channel Σ++c exchange. In our work, the final D0p results from the ground Λ+c(2286) state and also dominantly from the excited Λ+c(2940) state which is assumed as a D∗0p molecular state with spin parity JP=12+ or 12−. We calculate the total cross section of the π−p→D−D0p reaction. It is shown that the spin parity assignment of 12− for Λ+c(2940) gives a sizable enhancement for the total cross section in comparison with a choice of Jp=12+. However, our theoretical result of the total cross section is sensitive to the value of the cutoff parameter involved in the form factor of the exchanged off-shell particles. Moreover, we also calculate the second order differential cross section and find it can be used to determine the parity of the Λ+c(2940). It is expected that our model calculations can be tested by future experiments at J-PARC in Japan.
分类: 物理学 >> 核物理学 提交时间: 2016-09-01
摘要: We study the masses of open charm and bottom tetraquark states within the diquark-antidiquark scenario in the relativized quark model proposed by Godfrey and Isgur. The diquark and antidiquark masses are firstly solved by relativized quark potential, and then treated as the usual antiquark and quark, respectively. The masses of tetraquark states are obtained by solving the Schr\"{o}dinger-type equation between diquark and antidiquark. We find the masses of sqb¯q¯ tetraquark configuration are much higher than that of X(5568). This conclusion disfavors the possibility of X(5568) as a tetraquark state within the diquark-antidiquark scenario. Further experimental searches are needed to clarify the nature of the signal observed by D0 collaboration.
分类: 物理学 >> 核物理学 提交时间: 2016-08-31
摘要: We study the strong decay channels P+c(4380)→J/ψp and P+c(4450)→J/ψp under ΣcD¯∗ molecular state ansatz. With various spin-parity assignments, the partial decay widths of J/ψp final state are calculated. Our results show that all the P wave ΣcD¯∗ assignments are excluded, while S wave ΣcD¯∗ pictures for Pc(4380) and Pc(4450) are both allowed by present experimental data. The JP=3/2− Σ∗cD¯ and Σ∗cD¯∗ molecules are also discussed in the heavy quark limit, and find that the Σ∗cD¯ system for Pc(4380) is possible. More experimental information on spin-parities and partial decay widths and theoretical investigations on other decay modes are needed to clarify the nature of the two Pc states.