A search for the Z(3930) resonance in gamma gamma production of the D (D) over bar system has been performed using a data sample corresponding to an integrated luminosity of 384 fb(-1) recorded by the BABAR experiment at the PEP-II asymmetric-energy electron-positron collider. The D (D) over bar invariant mass distribution shows clear evidence of the Z(3930) state with a significance of 5.8 sigma. We determine mass and width values of (3926.7 +/- 2.7 +/- 1.1) MeV/c(2) and (21.3 +/- 6.8 +/- 3.6) MeV, respectively. A decay angular analysis provides evidence that the Z(3930) is a tensor state with positive parity and C parity (J(PC) = 2(++)); therefore we identify the Z(3930) state as the chi(c2)(2P) meson. The value of the partial width Gamma(gamma gamma) x B(Z(3930) -> D (D) over bar) is found to be (0.24 +/- 0.05 +/- 0.04) keV. RI Patrignani, Claudia/C-5223-2009; Neri, Nicola/G-3991-2012; Monge, Maria Roberta/G-9127-2012
Observation of the chi(c2)(2P) meson in the reaction gamma gamma -> D(D)over-bar at BABAR
ANGELINI, CARLO;BATIGNANI, GIOVANNI;BETTARINI, STEFANO;CALDERINI, GIOVANNI;FORTI, FRANCESCO;GIORGI, MARCELLO;MORGANTI, MAURO;PAOLONI, EUGENIO;RIZZO, GIULIANA;
2010-01-01
Abstract
A search for the Z(3930) resonance in gamma gamma production of the D (D) over bar system has been performed using a data sample corresponding to an integrated luminosity of 384 fb(-1) recorded by the BABAR experiment at the PEP-II asymmetric-energy electron-positron collider. The D (D) over bar invariant mass distribution shows clear evidence of the Z(3930) state with a significance of 5.8 sigma. We determine mass and width values of (3926.7 +/- 2.7 +/- 1.1) MeV/c(2) and (21.3 +/- 6.8 +/- 3.6) MeV, respectively. A decay angular analysis provides evidence that the Z(3930) is a tensor state with positive parity and C parity (J(PC) = 2(++)); therefore we identify the Z(3930) state as the chi(c2)(2P) meson. The value of the partial width Gamma(gamma gamma) x B(Z(3930) -> D (D) over bar) is found to be (0.24 +/- 0.05 +/- 0.04) keV. RI Patrignani, Claudia/C-5223-2009; Neri, Nicola/G-3991-2012; Monge, Maria Roberta/G-9127-2012I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
