PT Journal
AU BABAR Collaboration (Lees, JPea
   Martinez-Vidal, F
   Oyanguren, A
   Villanueva-Perez, P
TI Study of X (3915) -> J/psi omega in two-photon collisions
SO Physical Review D
JI Phys. Rev. D
PY 2012
BP 072002
EP 10pp
VL 86
IS 7
DI 10.1103/PhysRevD.86.072002
LA English
AB We study the process gamma gamma -> J/psi omega using a data sample of 519.2 fb(-1) recorded by the BABAR detector at SLAC at the PEP-II asymmetric-energy e(+)e(-) collider at center-of-mass energies near the gamma(nS) (n = 2, 3, 4) resonances. We confirm the existence of the charmoniumlike resonance X (3915) decaying to J/psi omega with a significance of 7.6 standard deviations, including systematic uncertainties, and measure its mass (3919.4 +/- 2.2 +/- 1.6) MeV/c(2) and width (13 +/- 6 +/- 3) MeV, where the first uncertainty is statistical and the second systematic. A spin-parity analysis supports the assignment J(P) = 0(+) and therefore the identification of the signal as due to the chi(c0)(2P) resonance. In this hypothesis we determine the product between the two-photon width and the final state branching fraction to be (52 +/- 10 +/- 3) eV.
ER