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$$\Lambda_b$$ results from CDF

Conference ·
DOI:https://doi.org/10.2172/371178· OSTI ID:371178
The CDF experiment has recorded 110 pb{sup {minus}1} of p{ovr p} collisions at {radical}s = 1.8 TeV during the 1992-1995 data taking period. Using this dataset, searches for inclusive and semileptonic {Lambda}{sub b} decays were performed. The {Lambda}{sub b} mass was measured to be M{sub {Lambda}{sub b}} {equals} 5623 {plus_minus} 5(stat.) {plus_minus} 4(syst.) MeV/c{sup 2}, using a sample of exclusively reconstructed {Lambda}{sub b} candidate events in the {Lambda}{sub b} {r_arrow} {Lambda}J/{psi} channel. The {Lambda}{sub b} lifetime was measured to be {tau}{sub {Lambda}{sub b}} {equals} 1. 32 {plus_minus} 0.08(stat.) {plus_minus} 0.05(syst.) ps, using a sample of 197 {plus_minus} 25 partially reconstructed semileptonic {Lambda}{sub b} {r_arrow} l{sup {minus}}{Lambda}{sub c}{sup {plus}}X decays, with {Lambda}{sub c}{sup {plus}} reconstructed from its decay to the pK{sup {minus}}{pi}{sup {plus}} final state. Using the same decay channels, the product branching ratios were measured to be f(b {r_arrow} {Lambda}{sub b})B({Lambda}{sub b} {r_arrow} {Lambda}J/{psi}) = 4.2{plus_minus}1.8(stat.){plus_minus}0.7(syst. ){times}10{sup {minus}5} and f(b {r_arrow} {Lambda}{sub b})B({Lambda}{sub b} {r_arrow} l{sup {minus}}{Lambda}{sub c}{sup {plus}}{ovr {nu}})B({Lambda}{sub c}{sup {plus}} {r_arrow} pK{sup {minus}}{pi}{sup {plus}}) {equals} 9.3{plus_minus}2.5(stat. ){plus_minus}{sup {plus}4.6}{sub {minus}4.0}(syst.){times}10{sup {minus}4}, where f(b {r_arrow} {Lambda}{sub b}) is the fraction of b quarks forming b baryons, and l is either an electron or a muon. 15 refs., 4 figs., 1 tab.
Research Organization:
Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
DOE Contract Number:
AC02-07CH11359
OSTI ID:
371178
Report Number(s):
PRINT-96-182 (FERMILAB); FERMILAB-CONF-96-165-E; oai:inspirehep.net:420419
Country of Publication:
United States
Language:
English