Relative transverse momentum distributions of bottom hadrons produced in 1.96 TeV proton-antiproton collisions

Roy, Philippe ; U., /McGill

Fermi National Accelerator Laboratory

关键词: Fragmentation;    Quantum Chromodynamics;    Accuracy;    Quarks;    Transverse Momentum Experiment-Hep;   

DOI  :  10.2172/936639
RP-ID  :  FERMILAB-MASTERS-2008-03
RP-ID  :  AC02-07CH11359
RP-ID  :  936639

美国|英语

来源: UNT Digital Library

【 摘 要 】

Fragmentation is the process by which bare quarks dress themselves up as hadrons. Since we cannot get reliable calculations of this process using perturbative quantum chromodynamics, the fragmentation properties of quarks must be obtained empirically. We report on the signal extraction and relative transverse momentum p{sub T} spectrum determination that will lead to a high precision measurement of relative fragmentation fractions of b quarks into B hadrons, in 1.96 TeV p{bar p} collisions. Using 1.9 fb{sup -1} of data taken with the CDF-II detector, we fully reconstruct 473 {+-} 42 B{sub s}{sup 0} {yields} D{sub s}{sup -} {pi}{sup +}, 15206 {+-} 203 B{sup 0} {yields} D{sup -} {pi}{sup +}, 1483 {+-} 45 B{sup 0} {yields} D*{sup -}{pi}{sup +} and 4444 {+-} 297 {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -} candidate decays. In order to reduce systematic uncertainties, ratios of p{sub T} spectra are reported. We find that B{sub s} and B{sup 0} mesons are produced with similar p{sub T} and {Lambda}{sub b} baryons are produced with lower p{sub T} than B{sup 0} mesons. Our results are consistent with previous CDF measurements suggesting a difference between fragmentation processes observed at lepton and hadron colliders.