Precise measurement of spin-averaged χcJ(1P) mass using photon conversions in ψ(2S)→γχcJ
Abstract
Using photon conversions to e+e- pairs, the energy spectrum of inclusive photons from ψ(2S) radiative decays is measured with photon energy resolution (σEγ) in the range from 2.3 to 3.8 MeV by BESII at the Beijing Electron-Positron Collider. The χcJ(1P) states (J=0,1,2) are clearly observed, and their masses and the spin-averaged χcJ mass are determined to be Mχc0=3414.21±0.39±0.27, Mχc1=3510.30±0.14±0.16, Mχc2=3555.70±0.59±0.39, and M(3Pcog)=3524.85±0.32±0.30 MeV/c2, respectively.
- Publication:
-
Physical Review D
- Pub Date:
- May 2005
- DOI:
- arXiv:
- arXiv:hep-ex/0502031
- Bibcode:
- 2005PhRvD..71i2002A
- Keywords:
-
- 14.40.Gx;
- 12.38.Qk;
- 13.25.Gv;
- 13.40.Hq;
- Mesons with S=C=B=0 mass>2.5 GeV;
- Experimental tests;
- Decays of J/psi Upsilon and other quarkonia;
- Electromagnetic decays;
- High Energy Physics - Experiment
- E-Print:
- 7 pages, 4 figures (one of them contain 3 sub-figtures). More descriptions on the fitting procedure are added. Additional figures, including the MC energy resolution distribution and pi0 mass distributions, are added