The cross sections for the hadroproduction of the chi(1) and chi(2) states of charmonium in proton-silicon collisions at root s = 38.8 GeV have been measured in Fermilab fixed target experiment 771. The chi states were observed via their radiative decay to J/psi gamma, where the photon converted to e(+)e(-) i(n) the material of the spectrometer. The estimated values for the chi(1) and chi(2) cross sections for x(F) > 0 are 263 +/- 69(stat) +/- 32(syst) and 498 +/- 143(stat) +/- 67(syst) nb per nucleon, respectively. The resulting sigma(chi(1))/sigma(chi(2)) ratio of 0.53 +/- 0.20(stat) +/- 0.07( syst), although somewhat larger than most theoretical expectations, can be accommodated by the latest theoretical estimates.
Hadroproduction of the Chi1 and Chi2 states of charmonium in 800 GeV/c Proto Silicon Interactions
GORINI, Edoardo
2000-01-01
Abstract
The cross sections for the hadroproduction of the chi(1) and chi(2) states of charmonium in proton-silicon collisions at root s = 38.8 GeV have been measured in Fermilab fixed target experiment 771. The chi states were observed via their radiative decay to J/psi gamma, where the photon converted to e(+)e(-) i(n) the material of the spectrometer. The estimated values for the chi(1) and chi(2) cross sections for x(F) > 0 are 263 +/- 69(stat) +/- 32(syst) and 498 +/- 143(stat) +/- 67(syst) nb per nucleon, respectively. The resulting sigma(chi(1))/sigma(chi(2)) ratio of 0.53 +/- 0.20(stat) +/- 0.07( syst), although somewhat larger than most theoretical expectations, can be accommodated by the latest theoretical estimates.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
