Study of the ππ mass spectra in the process e+e--->π+π-π0 at (s)~=1020 MeV
Abstract
The invariant mass spectra of the π+π- and π+/-π0 pairs in the process e+e--->π+π-π0 were studied in the Spherical Neutral Detector experiment at the VEPP-2M collider in the energy region (s)~=1020 MeV. These studies were based on about 0.5×106 events. The spectra were analyzed in the framework of the vector meson dominance model. It was found that the experimental data can be described assuming the e+e--->ρπ-->π+π-π0 transition only. An upper limit on the branching ratio of the φ(1020)-->π+π-π0 decay through intermediate states different from ρπ was obtained at the 90% confidence level: B(φ-->π+π-π0)<6×10-4. The ρ-meson mass and width which follow from the spectra analysis are mρ=775.0+/-1.3 MeV, Γρ=150.4+/-3.0 MeV. The mass difference of the neutral and charged ρ mesons was found to equal mρ+/--mρ0=-1.3+/-2.3 MeV. In the π+π- mass spectrum the ρ-ω interference was seen at a two standard deviation level.
- Publication:
-
Physical Review D
- Pub Date:
- February 2002
- DOI:
- 10.1103/PhysRevD.65.032002
- arXiv:
- arXiv:hep-ex/0106048
- Bibcode:
- 2002PhRvD..65c2002A
- Keywords:
-
- 13.65.+i;
- 12.40.Vv;
- 13.25.Jx;
- 14.40.Cs;
- Vector-meson dominance;
- Decays of other mesons;
- Other mesons with S=C=0 mass<
- 2.5 GeV;
- High Energy Physics - Experiment
- E-Print:
- 22 pages REVTEX and 19 figures