First Measurement of the Charge Asymmetry in Beauty-Quark Pair Production
Name
Aaij-2014-First measurement.pdf
Size
366.67 KB
Format
Adobe PDF
Checksum (MD5)
ef75cd1bdea87c7662754d7cd6b171a4
Author(s)
Counts, Ian Thomas Hunt
Williams, Michael
Ilten, Philip J
Date Issued
August 2014
Journal
Physical Review Letters
Publisher
American Physical Society
Citation
Aaij, R., B. Adeva, M. Adinolfi, A. Affolder, Z. Ajaltouni, S. Akar, J. Albrecht, et al. “First Measurement of the Charge Asymmetry in Beauty-Quark Pair Production.” Physical Review Letters 113, no. 8 (August 2014).
Version
Final published version
Abstract
The difference in the angular distributions between beauty quarks and antiquarks, referred to as the charge asymmetry, is measured for the first time in b[bar over b] pair production at a hadron collider. The data used correspond to an integrated luminosity of 1.0 fb[superscript −1] collected at 7 TeV center-of-mass energy in proton-proton collisions with the LHCb detector. The measurement is performed in three regions of the invariant mass of the b[bar over b] system. The results obtained are A[b[bar over b] over C](40 < M[subscript b[bar over b]] < 75 GeV/c[superscript 2]) = 0.4 ± 0.4 ± 0.3%, A[b[bar over b] over C](75 < M[subscript b[bar over b]] < 105 GeV/c[superscript 2]) = 2.0 ± 0.9 ± 0.6%, A[b[bar over b] over C](M[subscript b[bar over b]] > 105 GeV/c[superscript 2]) = 1.6 ± 1.7 ± 0.6%, where A[b[bar over b] over C] is defined as the asymmetry in the difference in rapidity between jets formed from the beauty quark and antiquark, where in each case the first uncertainty is statistical and the second systematic. The beauty jets are required to satisfy 2 < η < 4, E[subscript T] > 20 GeV, and have an opening angle in the transverse plane Δϕ > 2.6 rad. These measurements are consistent with the predictions of the standard model.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Massachusetts Institute of Technology. Laboratory for Nuclear Science
Terms of Use
Creative Commons Attribution
Persistent DSpace Link
DOI of Published Version
http://dx.doi.org/10.1103/PhysRevLett.113.082003
