We have studied the process e(+)e(-)-->mu(+)mu(-)gamma at a center-of-mass energy near the Y(4S) resonance for a mu(+)mu(-) invariant mass range near the J/psi mass and measured the cross section sigma(e(+)e(-)-->J/psi gamma-->mu(+)mu(-)gamma). The data set, corresponding to an integrated luminosity of 88.4 fb(-1), was collected using the BABAR detector at the SLAC PEP-II collider. From the measured cross section we extract the product Gamma(J/psi-->e(+)e(-))B(J/psi-->mu(+)mu(-))=0.330+/-0.008+/-0.007 keV. Using the world averages for B(J/psi-->mu(+)mu(-)) and B(J/psi-->e(+)e(-)), we derive the J/psi electronic and total widths: Gamma(J/psi-->e(+)e(-))=5.61+/-0.20 keV and Gamma=94.7+/-4.4 keV.
J/psi production via initial state radiation in e(+)e(-)->mu(+)mu(-)gamma at an e(+)e(-) center-of-mass energy near 10.6 GeV
ANDREOTTI, Mirco;AZZOLINI, Virginia;CALABRESE, Roberto;CIBINETTO, Gianluigi;LUPPI, Eleonora;NEGRINI, Matteo;
2004
Abstract
We have studied the process e(+)e(-)-->mu(+)mu(-)gamma at a center-of-mass energy near the Y(4S) resonance for a mu(+)mu(-) invariant mass range near the J/psi mass and measured the cross section sigma(e(+)e(-)-->J/psi gamma-->mu(+)mu(-)gamma). The data set, corresponding to an integrated luminosity of 88.4 fb(-1), was collected using the BABAR detector at the SLAC PEP-II collider. From the measured cross section we extract the product Gamma(J/psi-->e(+)e(-))B(J/psi-->mu(+)mu(-))=0.330+/-0.008+/-0.007 keV. Using the world averages for B(J/psi-->mu(+)mu(-)) and B(J/psi-->e(+)e(-)), we derive the J/psi electronic and total widths: Gamma(J/psi-->e(+)e(-))=5.61+/-0.20 keV and Gamma=94.7+/-4.4 keV.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
