CMS DP-2013/026 ECAL Upgrade performance plots (2)
Abstract: ECAL upgrade performance plots for 2013 LHCC and ECFA
iCMS entry
,
Figure |
Caption |
pdf version, eps version |
Contribution of ECAL ageing on the Higgs mass resolution The plot shows the contribution to the Higgs mass resolution due to the ECAL ageing, for the two photon decay of the Higgs boson, as a function of the maximum pseudo-rapidity of the photon pair. The mass resolution is calculated using a sample of events generated with the Pythia Monte Carlo program at TeV. For each event the photon energy is smeared using a gaussian smearing according to the test-beam ECAL energy resolution in the Barrel (EB) and Endcaps (EE). The degradation of the energy resolution, due to radiation, is based on the prediction of the crystal light output evolution calculated by the LITRANI program [1] as a function of the γ dose and hadron fluence, given by the MARS program [2] for various integrated luminosities, together with the average VPT response loss expected from laboratory measurements. The ageing contribution to the mass resolution is calculated as the difference in quadrature between the mass resolution calculated with the ageing and the nominal mass resolution. [1] F.-X. Gentit, Nucl. Instr. Meth. A 486 (2002) 35–39, 1036 doi:10.1016/S0168-9002(02)00671-X. [2] P.C. Bhat et al., CERN-CMS-NOTE-2013-001. |
pdf version, eps version pdf version, eps version pdf version, eps version pdf version, eps version |
L1 trigger linearization coefficients Linearization of the L1 trigger response: The signal for each channel (in ADC counts) is multiplied by a factor [1] depending on IC, Gain, η, laser corrections to provide a signal that is proportional to the transverse energy deposited in the crystal. This factor is encoded using 8 bits (mult) with a 4-bit exponent (shift) to keep an optimal resolution for low values ( ). It saturates at 255. The plots show the values of these coefficients in the ECAL endcaps for various ageing scenarios. The coefficients have been calculated assuming that the crystal light output evolves according to the predictions of the model by the LITRANI program [2] as a function of the γ dose and hadron fluence, given by the MARS program [3] for various integrated luminosities. The degradation of the light output of the inner EE eta rings cannot be compensated for at the trigger level at these high values of integrated luminosity without significantly increasing the triggering threshold. The electron/photon L1 trigger in EE will therefore gradually lose acceptance from the inner eta rings outwards [1] P. Paganini, J. Phys. Conf. Ser. 160 (2009) 012062. [2] F.-X. Gentit, Nucl. Instr. Meth. A 486 (2002) 35–39, 1036 doi:10.1016/S0168-9002(02)00671-X. [3] P.C. Bhat et al., CERN-CMS-NOTE-2013-001. |