We present a quantitative analysis of the DsJ+(2632) observed by SELEX mainly focusing on the assumption that DsJ +(2632) is the first radial excitation of the 1- ground state Ds*(2112). By solving the instantaneous Bethe-Salpeter equation, we obtain the mass 2658±15 MeV for the first excited state, which is about 26 MeV heavier than the experimental value 2632±1.7 MeV. By means of PCAC and low-energy theorem we calculate the transition matrix elements and obtain the decay widths: Γ(DsJ+→ Ds+η)=4.07±0.34 MeV, Γ(D sJ+→D0K+) ≃Γ(Γ(DsJ+→D+K 0)=8.9±1.2 MeV, and the ratio Γ(DsJ +→D0K+)/Γ(DsJ +→Ds+η)=2.2±0.2 as well. This ratio is quite different from the SELEX data 0.14±0.06. The summed decay width of those three channels is approximately 21.7 MeV, already larger than the observed bound for the full width (≤17 MeV). Furthermore, assuming D sJ+(2632) is 1- state, we also explore the possibility of S-D wave mixing to explain the SELEX observation. Based on our analysis, we suspect that it is too early to conclude that DsJ +(2632) is the first radial excitation of the 1- ground state Ds*(2112). More precise measurements of the relative ratios and the total decay width are urgently required, especially for S-D wave mixing.
|Number of pages||9|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 2005 Sep 15|
Bibliographical noteFunding Information:
We would like to thank G. Cvetič for careful reading of the manuscript and his valuable comments. This work of C.H.C. and G.L.W. was supported by the National Natural Science Foundation of China (NSFC). The work of C.S.K. was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) No. R02-2003-000-10050-0. The work of G.L.W. was supported in part by CHEP-SRC Program and in part by Grant No. F01-2004-000-10292-0 of KOSEF-NSFC International Collaborative Research Grant.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics