Measurement of the Relative Fragmentation Fractions of B-bar Hadrons PDF Download

Author: Karen Ruth Gibson
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ISBN:
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Languages : en
Pages : 169

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Book Description
This thesis describes the first Run II measurement of b quark fragmentation into {bar B}{sup 0}, B{sup -}, and {bar B}{sub s}{sup 0} mesons and {Lambda}{sub b}{sup 0} baryons using semileptonic B decays. The result is based on 360 pb{sup -1} of data collected with the CDF detector in p{bar p} collisions at {radical}s = 1,960 GeV at the Tevatron Collider at Fermilab. The fragmentation fractions are measured for an effective {bar B} hadron p{sub T} threshold of 7 GeV/c to be f{sub u}/f{sub d} = 1.054 {+-} 0.018(stat){sub -0.045}{sup +0.025}(syst) {+-} 0.058(BR), f{sub s}/(f{sub u} + f{sub d}) = 0.160 {+-} 0.005(stat){sub -0.010}{sup +0.011}(syst){sub -0.034}{sup +0.057}(BR), and f{sub {Lambda}{sub b}}/(f{sub u} + f{sub d}) = 0.281 {+-} 0.012(stat){sub -0.056}{sup +0.058}(syst){sub -0.086}{sup +0.128}(BR). f{sub s}/(f{sub u} + f{sub d}) agrees both with previous CDF measurements and the world averages, dominated by the LEP measurements, with {approx} 1{sigma}. However, f{sub {Lambda}{sub b}}/(f{sub u} + f{sub d}) is approximately twice the value which has been measured at LEP and in CDF Run I and disagrees with the LEP results by approximately 2 {sigma}.