Search

We use a unitary coupled-channel model to study the interactions. In our calculation, SU(3) flavor symmetry is applied to determine the coupling constants. Several resonant and bound states with different spin and parity are dynamically generated in the mass range of the recently observed pentaquarks. The approach is also extended to the hidden beauty sector to study the interactions. As the b-quark mass is heavier than the c-quark mass, there are more resonances observed for the interactions and they are more tightly bound.

A new particle σ* with JP = 1/2− was predicted by unquenched quark models with its mass around the well established σ* (1385) with JP = 3/2+. Here we re-examine some old data of the K− p → Λπ−π+ reaction. Firstly we re-fit the data for kaon beam momenta in the range of 1.0–1.8 GeV. Secondly we study the reaction at the energies around Λ* (1520) peak. Both studies show evidence for the existence of σ* with JP = 1/2− around 1380 MeV. Higher statistic data on relevant reactions are needed to clarify the situation.

Abundant Ψ' events have been collected at the Beijing Electron Positron Collider- II (BEPCII) that could undoubtedly provide us with a great opportunity to study the more attractive charmonium decays. As has been noticed before, in the process of J/Ψ decaying to the baryonic final states, pK−, the evident Λ* and N* bands have been observed. Similarly, by using the product of χcJ from Ψ' radiative decay, we may confirm this or find some extra new resonances. χc0's data samples will be more than χc1,2, taking into account the larger branching ratio of Ψ' → γχc0. Here, we provide explicit partial wave analysis formulae for the very interesting channel Ψ' → γχc0 → γpK−.

We analyze the meson production in e+e− → ωπ0 as a probe for studying the isospin violation mechanisms. By clarifying the dynamic sources causing the isospin violation, we succeed in quantifying those mechanisms with the help of the recent KLOE data. Hence, the → ωπ0 branching ratio is extracted. We find that apart from the electromagnetic (EM) transitions, the strong transition via intermediate kaon loops plays an important role in understanding the cross section and its lineshape.

In this proceeding, we propose to directly measure the a00(980)-f0 (980) mixing in J/ψ → f0(980) → a00 (980) and χc1 → π0a00(980) → π0f0(980) with the upgraded Beijing Electron Positron Collider(BEPCII) with BESIII detector. We show that a narrow peak of about 8 MeV will be produced by the a00(980)-f0 (980) mixing, and the predominant feature makes it standing out from the background contributions. The predicted branching ratios for these two reactions are both expected to be about O(10−6), which is unambiguously accessible with 109 J/ψ and 3 × 108 χc1 at BESIII.