MET Express Stream Noise Monitoring/Analysis

Introduction

Because resolution of physics objects is largely affected by calorimeter noise, the goal of the MET express stream studies is to look at relevant quantities from the standpoint of both physics and calorimeter noise. The general goal is to provide quick feedback in case noise rates increase, analyze calorimeter based quantities and the contributions due to calorimeter noise, look at variables that are relevant for cleaning/correcting, monitor rates, extract biases due to certain cleaning variables, shed some insight in to efficiencies of these variables on "physics" objects as well as "noise" objects. We can do all of this with the met express stream quickly and do it in a "global" way (met, jets, hcal, ecal, ...). This is done at both the DQM level (Hcal DQM - DetDiagNoseMonitoring) & offline analysis level.

Details of Algorithms

Noise Tagging Algorithms for MET cleaning/filtering:

• HB/HE Noise - (jet charged fraction < 0.05 and jet HadF > 0.98) OR (RBX Energy > 50 and (RBX E(2TS)/E(10TS) < 0.65 OR RBX E(2TS)/E(10TS) > 0.95) and HPD Max Hits >= 17 and RBX ADC 0's >= 10)
• HF Noise - Not masked and ( (E_L - E_S) / (E_L + E_S) < -0.8 OR (E_L - E_S) / (E_L + E_S) > 0.99 )
• EB Noise - S4 / S1 < (0.04 * log10( E_seed / 4.0 ))

Results

See MET Express Noise Monitoring Page for all details and plots. Go to Link "7 TeV Collision Runs (2010) "

-- AlfredoGurrola - 30-Mar-2010