This paper describes the first measurement of b-quark fragmentation fractions into bottom hadrons in Run II of the Tevatron Collider at Fermilab. The result is based on a 360 pb(-1) sample of data collected with the CDF II detector in p (p) over bar collisions at root s = 1.96 TeV. Semileptonic decays of (B) over bar (0), B(-), and (B) over bar (0)(s) mesons, as well as Lambda(0)(b) baryons, are reconstructed. For an effective bottom hadron p(T) threshold of 7 GeV/c, the fragmentation fractions are measured to be f(u)/f(d)=1.054 +/- 0.018(stat)(-0.045)(+0.025)(sys)+/- 0.058(B), f(s)/(f(u)+f(d))=0.160 +/- 0.005(stat)(-0.010)(+0.011)(sys)(-0.034)(+0.057)(B), and f(Lambda b)/(f(u)+f(d))=0.281 +/- 0.012(stat)(-0.056)(+0.058)(sys)(-0.087)(+0.128)(B), where the uncertainty B is due to uncertainties on measured branching ratios. The value of f(s)/(f(u)+f(d)) agrees within one standard deviation with previous CDF measurements and the world average of this quantity, which is dominated by LEP measurements. However, the ratio f(Lambda b)/(f(u)+f(d)) is approximately twice the value previously measured at LEP. The approximately 2 sigma discrepancy is examined in terms of kinematic differences between the two production environments.

T., A., J., A., T., A., M. G., A., B. A., G., S., A., et al. (2008). Measurement of ratios of fragmentation fractions for bottom hadrons in p(p)over-bar collisions at root s=1.96 TeV. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 77(7), 072003-1-072003-31 [10.1103/PhysRevD.77.072003].

Measurement of ratios of fragmentation fractions for bottom hadrons in p(p)over-bar collisions at root s=1.96 TeV

CIOCCI, MARIA AGNESE;
2008-01-01

Abstract

This paper describes the first measurement of b-quark fragmentation fractions into bottom hadrons in Run II of the Tevatron Collider at Fermilab. The result is based on a 360 pb(-1) sample of data collected with the CDF II detector in p (p) over bar collisions at root s = 1.96 TeV. Semileptonic decays of (B) over bar (0), B(-), and (B) over bar (0)(s) mesons, as well as Lambda(0)(b) baryons, are reconstructed. For an effective bottom hadron p(T) threshold of 7 GeV/c, the fragmentation fractions are measured to be f(u)/f(d)=1.054 +/- 0.018(stat)(-0.045)(+0.025)(sys)+/- 0.058(B), f(s)/(f(u)+f(d))=0.160 +/- 0.005(stat)(-0.010)(+0.011)(sys)(-0.034)(+0.057)(B), and f(Lambda b)/(f(u)+f(d))=0.281 +/- 0.012(stat)(-0.056)(+0.058)(sys)(-0.087)(+0.128)(B), where the uncertainty B is due to uncertainties on measured branching ratios. The value of f(s)/(f(u)+f(d)) agrees within one standard deviation with previous CDF measurements and the world average of this quantity, which is dominated by LEP measurements. However, the ratio f(Lambda b)/(f(u)+f(d)) is approximately twice the value previously measured at LEP. The approximately 2 sigma discrepancy is examined in terms of kinematic differences between the two production environments.
2008
T., A., J., A., T., A., M. G., A., B. A., G., S., A., et al. (2008). Measurement of ratios of fragmentation fractions for bottom hadrons in p(p)over-bar collisions at root s=1.96 TeV. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 77(7), 072003-1-072003-31 [10.1103/PhysRevD.77.072003].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/37251
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