Tau energy scale systematics Matteo Volpi Tau WG

Tau energy scale systematics Matteo Volpi Tau. WG 28 June 2011 1

Method description Like last year, the systematic uncertainties on the tau energy scale are evaluated using Monte Carlo studies. Define the scale as reconstructed energy minus the true visible energy divided by true visible energy (ETRec - ETTrue)/ETTrue. Bin the response in true energy (ET): [15 to 20 Ge. V, 30 to 40 Ge. V, 40 to 50 Ge. V , 50 to 70 Ge. V, > 70 Ge. V ]. Bin the response in |η| of true tau: [ |η| <1. 3, 1. 3 < |η| < 1. 6 , |η| > 1. 6]. Motivated by calorimeter cracks. Separate the samples into one and multi prongs. Match true visible tau with reconstructed tau using ΔR < 0. 2. We require that all taus considered pass: tau_tau. Cut. Loose to be true (in the D 3 PD). This cut is applied to all the samples used in this analysis. 2

Systematic uncertainties (1 prong) Add underlying event systematic from last year analysis. After apply tau. Cut. Loose we reduce the statistic but we have better resolution. The statistical fluctuation is almost negligible. 3

Systematic uncertainties (1 prong) After apply the tau. Cut. Loose we reduce the neutral component of the jets. Less systematic in the 60 Ge. V bin for the hadron shower fluctuation ( less # of particles at low energy). 4

Systematic uncertainties (3 prong) 5

Systematic uncertainties summary 1 prong |η| < 1. 3 < |η| < 1. 6 |η| > 1. 6 15 < ET < 20 5. 5% 5% 4. 5% 20 < ET < 30 4. 5% 5% 4. 5% ET > 30 3. 5% 5% 4. 5% Multi-prong |η| < 1. 3 Multi-prong 1. 3 < |η| < 1. 6 |η| > 1. 6 15 < ET < 30 6. 5% 15 < ET < 20 9. 5% 6. 5% 30 < ET < 40 5. 5% 20 < ET < 40 5. 5% ET > 40 5% 5% 4. 5% d Ol lues va We almost have the same systematic from last time. 6

Extra slides 7

Systematic uncertainties summary Again the statistical fluctuation is almost negligible. After apply tau. Cut. Loose we reduce the statistic but we have better resolution. 8