Measurement of the parity-violating asymmetry parameter $α_b$ and the helicity amplitudes for the decay $Λ_b^0\\to J/ψ+Λ^0$ with the ATLAS detector
Journal
Physical Review
Journal Volume
D89
Journal Issue
9
Pages
092009
Date Issued
2014
Author(s)
Abstract
A measurement of the parity-violating decay asymmetry parameter, αb, and the helicity amplitudes for the decay Λb0→J/ψ(μ+μ-)Λ0(pπ-) is reported. The analysis is based on 1400 Λb0 and Λ¯b0 baryons selected in 4.6 fb-1 of proton-proton collision data with a center-of-mass energy of 7 TeV recorded by the ATLAS experiment at the LHC. By combining the Λb0 and Λ¯b0 samples under the assumption of CP conservation, the value of αb is measured to be 0.30±0.16(stat)±0.06(syst). This measurement provides a test of theoretical models based on perturbative QCD or heavy-quark effective theory.
Type
journal article