Measurement of $\tau$ polarization in $W \to \tau\nu$ decays with the ATLAS detector in pp collisions at $\sqrt{s}$ = 7 TeV
- Aad, Georges et al
- arXiv:1204.6720CERN-PH-EP-2012-075
| noimg: Definition of the phase space for the measurement of $\tau$~polarization in terms of the true $\tau$~visible decay product and neutrino kinematic variables~\cite{WtauXS}.: Number of events passing the full event selection for data, the Monte Carlo electroweak background estimate (which is independent of the assumed $\tau$~polarization), the Monte Carlo $\Wtaunu$ signal for left-handed and right-handed polarization, and the multijet background estimated from data. The multijet background estimates are corrected for signal contamination and therefore depend on the $\tau$~polarization. The data should be compared to the sum of the appropriate $\Wtaunu$ signal entry plus the electroweak and multijet background estimates. The errors denote the statistical uncertainty from the Monte Carlo samples. |
| Track \pt |
| Tau \ptEM radius |
| Kinematic distributions for $\tau$~candidates. The combined statistical and energy scale systematic uncertainties are overlaid on the stacked left-handed signal and background distributions. The stacked right-handed $\Wtaunu$ simulated signal and background distribution is also shown.Caption not extracted |
| Missing transverse momentum |
| Missing transverse momentum significanceEvent kinematic distributions. The combined statistical and energy scale systematic uncertainties are overlaid on the stacked left-handed signal and background distributions. The stacked right-handed $\Wtaunu$ simulated signal and background distribution is also shown. |
| Left-handed |
| Right-handedCharged asymmetry distributions. The combined statistical and energy scale systematic uncertainties are overlaid on the stacked signal and background distributions. |
| Simulated signal and background templates for left-handed and right-handed $\tau$~decays along with the observed charged asymmetry distribution in data. The best fit resulting from maximizing the likelihood is plotted in bold. |