The cross sections for the hadroproduction of the χ1 and χ2 states of charmonium in proton-silicon collisions at √s=38.8 GeV have been measured in Fermilab fixed target experiment 771. The χ states were observed via their radiative decay to J/ψγ, where the photon converted to e+e- in the material of the spectrometer. The estimated values for the χ1 and χ2 cross sections for xF>0 are 263±69(stat)±32(syst) and 498±143(stat)±67(syst) nb per nucleon, respectively. The resulting σ(χ1)/σ(χ2) 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. ©2000 The American Physical Society.
Hadroproduction of the χ1 and χ2 states of charmonium in 800-GeV/c proton-silicon interactions
Bonomi G.;
2000-01-01
Abstract
The cross sections for the hadroproduction of the χ1 and χ2 states of charmonium in proton-silicon collisions at √s=38.8 GeV have been measured in Fermilab fixed target experiment 771. The χ states were observed via their radiative decay to J/ψγ, where the photon converted to e+e- in the material of the spectrometer. The estimated values for the χ1 and χ2 cross sections for xF>0 are 263±69(stat)±32(syst) and 498±143(stat)±67(syst) nb per nucleon, respectively. The resulting σ(χ1)/σ(χ2) 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. ©2000 The American Physical Society.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
