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Observation of a Charged(DD¯*)±Mass Peak ine+e−→πDD¯*ats=4.26 GeV
- Source :
- Physical Review Letters. 112
- Publication Year :
- 2014
- Publisher :
- American Physical Society (APS), 2014.
-
Abstract
- We report on a study of the process e(+)e(-) -> pi(+/-) (D (D) over bar*)(-/+) at root s = 4.26 GeV using a 525 pb(-1) data sample collected with the BESIII detector at the BEPCII storage ring. A distinct charged structure is observed in the (D (D) over bar*)(-/+) invariant mass distribution. When fitted to a mass- dependent- width Breit- Wigner line shape, the pole mass and width are determined to be M-pole (3883: 9 +/- 1.5 (stat) +/- 4.2 dsyst__ MeV= c(2) and Gamma(pole) = (24: 8 +/- 3.3 (stat) +/- 11: 0 (syst)) MeV. The mass and width of the structure, which we refer to as Z(c)(3885), are 2 sigma and 1 sigma, respectively, below those of the Z(c)(3900) -> pi(+/-) J/psi peak observed by BESIII and Belle in pi(+)pi(-) J/psi final states produced at the same center- of- mass energy. The angular distribution of the pi Z(c)(3885) system favors a J(P) = J(P) = 1(+) quantum number assignment for the structure and disfavors 1(-) or 0(-). The Born cross section times the (D (D) over bar*) branching fraction of the Z(c)(3885) is measured to be sigma(e(+)e(-) -> pi(+/-)Z(c)(3885)(-/+)) x B(Z(c)(3885)-/+ -> (D (D) over bar*)(-/+) = (83.5 +/- 6.6 (stat) +/- 22.0 (syst)) pb. Assuming the Z(c)(3885) -> (D (D) over bar*)(-/+) signal reported here and the Z(c)(3900) -> pi J/psi signal are from the same source, the partial width ratio (Gamma(Z(c)(3885) -> D (D) over bar*)/Gamma(Z(c)(3900) -> pi J/psi)) = 6.2 +/- 1.1 (stat) +/- 2.7 (syst) is determined.
Details
- ISSN :
- 10797114 and 00319007
- Volume :
- 112
- Database :
- OpenAIRE
- Journal :
- Physical Review Letters
- Accession number :
- edsair.doi...........8cdcbdf8dcbb30e64268f328dea97b92
- Full Text :
- https://doi.org/10.1103/physrevlett.112.022001