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Title: Measurement of the Forward-Backward Asymmetry in the Production of $$B^{\pm}$$ Mesons in $$p\bar{p}$$ Collisions.

Abstract

We present a measurement of the forward-backward asymmetry in the production of B ± mesons, A FB(B ±), using B ± → J/ψK ± decays in 10.4 fb -1 of p$$\bar{p}$$ collisions at √ s = 1.96 TeV collected by the DØ experiment during Run II of the Tevatron collider. A nonzero asymmetry would indicate a preference for a particular flavor, i.e., b quark or $$\bar{b}$$ antiquark, to be produced in the direction of the proton beam. We extract A FB(B ±) from a maximum likelihood fit to the difference between the numbers of forward- and backward-produced B ± mesons, using a boosted decision tree to reduce background. Corrections are made for reconstruction asymmetries of the decay products. We measure an asymmetry consistent with zero: A FB(B ±) = [-0.24 ± 0.41 (stat)± 0.19 (syst)]%. The standard model estimate from next-to-leading-order Monte Carlo is A SM FB(B ±) = [2.31 ± 0.34 (stat.)± 0.51 (syst.)]%. There is a difference of ≈ 3 standard deviations between this prediction and our result, which suggests that more rigorous determination of the standard model prediction is needed to interpret these results.

Authors:
 [1]
  1. Rice Univ., Houston, TX (United States)
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1172584
Report Number(s):
FERMILAB-THESIS-2015-01
DOE Contract Number:  
AC02-07CH11359
Resource Type:
Thesis/Dissertation
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Hogan, Julie Managan. Measurement of the Forward-Backward Asymmetry in the Production of $B^{\pm}$ Mesons in $p\bar{p}$ Collisions.. United States: N. p., 2015. Web. doi:10.2172/1172584.
Hogan, Julie Managan. Measurement of the Forward-Backward Asymmetry in the Production of $B^{\pm}$ Mesons in $p\bar{p}$ Collisions.. United States. doi:10.2172/1172584.
Hogan, Julie Managan. Sun . "Measurement of the Forward-Backward Asymmetry in the Production of $B^{\pm}$ Mesons in $p\bar{p}$ Collisions.". United States. doi:10.2172/1172584. https://www.osti.gov/servlets/purl/1172584.
@article{osti_1172584,
title = {Measurement of the Forward-Backward Asymmetry in the Production of $B^{\pm}$ Mesons in $p\bar{p}$ Collisions.},
author = {Hogan, Julie Managan},
abstractNote = {We present a measurement of the forward-backward asymmetry in the production of B± mesons, AFB(B±), using B± → J/ψK± decays in 10.4 fb -1 of p$\bar{p}$ collisions at √ s = 1.96 TeV collected by the DØ experiment during Run II of the Tevatron collider. A nonzero asymmetry would indicate a preference for a particular flavor, i.e., b quark or $\bar{b}$ antiquark, to be produced in the direction of the proton beam. We extract AFB(B±) from a maximum likelihood fit to the difference between the numbers of forward- and backward-produced B± mesons, using a boosted decision tree to reduce background. Corrections are made for reconstruction asymmetries of the decay products. We measure an asymmetry consistent with zero: AFB(B±) = [-0.24 ± 0.41 (stat)± 0.19 (syst)]%. The standard model estimate from next-to-leading-order Monte Carlo is ASM FB(B±) = [2.31 ± 0.34 (stat.)± 0.51 (syst.)]%. There is a difference of ≈ 3 standard deviations between this prediction and our result, which suggests that more rigorous determination of the standard model prediction is needed to interpret these results.},
doi = {10.2172/1172584},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Feb 01 00:00:00 EST 2015},
month = {Sun Feb 01 00:00:00 EST 2015}
}

Thesis/Dissertation:
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