Approval Plots for Redundancy study

Enhancement of performance in nominal muon coverage

MS_allstations_11august.pdf

The RMS of multiple scattering displacement as a function of muon p_T for the different forward muon stations. All the electromagnetic processes such as bremsstrahlung and magnetic field effect are included in the simulation. In the forward region, we expect a poor momentum resolution of muons with respect to the one in the barrel region caused by magnetic inhomogeneity, shower effects at high momenta and by the lower number of measured points with respect to the rest of the CMS muon system. Additional detectors in the muon system, with good spatial resolution, can improve limited p_T resolution in the current endcap region and will provide higher efficiency in a high background environment. The multiple scattering displacement numbers for each p_T is obtained by the muon gun sample starting at (0,0,0) with no primary beam smearing and pointing to a fixed eta (at the center of chamber) and phi. So the distribution of muon sim hit position only given by the material effects and RMS of this distribution on the y-axis represents the lower limit of spatial resolution set by the multiple scattering experienced by the muon travelling through the CMS material. The RMS of the displacement for p_T = 200 GeV is about 500 µm at the surface of GE1/1, about 1 mm at GE2/1, and reaches 3-4 mm at the fourth station (RE4/1) as can be seen on the figure and according to these numbers, the baseline is set for the number of strips.

Redundancy plot for STA reconstruction: 2019 scenario, PU = 0

Sigma_pt100_SA19_TP_11august.pdf

Restoration of q/p_T resolution by adding GE1/1 in case of ME1/1 failure in the “2019 scenario”. Same results also obtained for RMS. q/p_T resolution is defined as the gaussian width of:
δ( q/p_T) / q/p_T = (q^rec/p^rec_T - q^sim/p^sim_T) / (q^sim/p^sim_T)
Sigma of the q/p_T resolution is obtained from its gausian fit in the range of [(mean - 2 * RMS), (mean + 2 * RMS)]. Since the sample contains no tracks from pileup, so association by dR is used for making this plot, where simToReco association with smallest dR is taken.The lack of redundancy of the present muon system in the forward region at HL-LHC will be an important issue in case of failure of any segment of CSC or the whole detector. We have studied the performance of q/p_T resolution considering the case in which one segment in CSC is lost. The figure shows the improvement in gaussian width of the q/p_T resolution provided by the addition of the GE1/1 chambers in the case of failure of ME1/1 chambers. GE1/1 can nearly compensate such failure, since the contribution of GE1/1 and ME1/1 in the resolution is nearly same (Blue triangles and green squares)

Redundancy plot for STA reconstruction: 2023 scenario, PU = 0

Ratio_rms_pt100_TP_11august.pdf

Improvement of the q/p_T resolution in the “2023 scenario” with different failure configurations. The RMS shown in the distribution is taken from the gaussian width of q/p_T plotted in the range of [-6,+6] using association by dR. In addition to the ME1/1 case, we have masked one by one also ME2/1, ME3/1 and ME4/1. And to visualize the effect in one canvas w.r.t. the normal configuration we have plotted the ratio:
(MEX/Y masked in presence of the muon system upgrade) / (MEX/Y masked without the help of the muon system upgrade)
Figure shows that the standalone muon performance is restored in case of failure of either ME1/1 or ME2/1 or ME3/1 or ME4/1 station adding new detector (GE1/1, GE2/1, RE3/1, RE4/1 respectively). As expected the major recovery (up to 60%) is obtained in case of the failure of first two stations. Black filled dots provide the general gain with and without upgrade detector (up to around 35%)

Redundancy plot for STA reconstruction in 2023 scenario, PU = 140: Sigma of q/p_T resolution

Sigma_redundancy_PU_newsamples.pdf

Restoration of q/p_T resolution by adding the upgrade detectors in case of ME1/1 failure in the “2023 scenario” at PU = 140 using association by Chi2 for taking care of the tracks coming from PU. Sigma of the q/p_T resolution is obtained from its gausian fit in the range of [(mean - 2 * RMS), (mean + 2 * RMS)]. Improvement in gaussian width of q/p_T provided by the addition of upgrade detectors in case of failure of ME1/1 chambers (black points), almost same behavior as observed in PU = 0, 2019 scenario as expected.

RatioSigma_PU_redundancy_newsamples.pdf

Improvement of the q/p_T resolution in the “2023 scenario” at PU = 140 with different failure configurations. Standalone muon performance is restored in case of failure of either ME1/1, or ME2/1 or ME3/1 or ME4/1 station adding new detectors (GE1/1, GE2/1, RE3/1 and RE4/1 respectively) for the “2023” PU = 140 scenario. Major recovery (more than 90%) is obtained by adding GE1/1 (square filled markers) and (more than 60%) GE2/1 (triangle filled markers) due to higher spatial resolution.

Redundancy plot for STA reconstruction in 2023 scenario, PU = 140: RMS of q/p_T resolution

RMS_redundancy_PU_newsamples.pdf

Restoration of RMS of q/p_T resolution by adding the upgrade detectors in case of ME1/1 failure in the “2023 scenario” at PU = 140 using association by Chi2 plotted in the range [-6,+6]. Recovery in the RMS of the resolution obtained with upgrade detectors in case of the failure of ME1/1.

RatioRMS_PU_redundancy_newsamples.pdf

The RMS of q/p_T resolution studied in the hypothesis of completely broken ME1/1, ME2/1, ME3/1, ME4/1 (one at a time) and their ratios are plotted to visualize the recovery we can get with Muon system Upgrade and its magnitude. It is clear from the plot at Standalone muon performance is restored in case of failure of either ME1/1, or ME2/1 or ME3/1 or ME4/1 station adding new detectors (GE1/1, GE2/1, RE3/1 and RE4/1 respectively) for the “2023” PU = 140 scenario.

Redundancy plot for STA reconstruction in 2023 scenario, PU = 140: Charge mid-id rate

Chargemisid_redundancy_PU_newsamples.pdf

The study of the charge mis-identification rate by adding the upgrade detectors in case of ME1/1 failure in the “2023 scenario” at PU = 140 using association by Chi2.
Charge mis-id Rate = (≠ of reco muons with wrong charge assignment (Sim charge - Reco Charge ≠ 0)) / (≠ of total of reco muons)
Large charge mis-identification rate in the catastrophic scenario where ME1/1 is completely broken also at PU =140 (black points). The improvement up to 25% can be seen with the upgrade detectors.

RatioChargemisid_PU_redundancy_newsamples.pdf

Same like the case of q/p_T resolution, charge mid-identification rate studied in the hypothesis of completely broken ME1/1, ME2/1, ME3/1, ME4/1 (one at a time) and their ratios are plotted to visualize the recovery we can get with Muon system Upgrade and its magnitude. The performance of charge mis-identification rate for standalone muons is restored in case of failure of either ME1/1, or ME2/1 or ME3/1 or ME4/1 station adding new detectors (GE1/1, GE2/1, RE3/1 and RE4/1 respectively) for the “2023” PU = 140 scenario.

Performance plots for PU = 140 sample in 2023 scenario: Sigma of q/p_T resolution

Sigma_PU140_XL_newscale.pdf

Improvements in the Sigma of q/p_T resolution with added redundancy of the upgrade forward muon detectors, for standalone muons, as a function of the simulated η for p_T = 100 GeV at 140 PU. The range between [mean-2*RMS, mean+2*RMS] is used for fitting of the q/p_T resolution plotted in the range of [-6,+6]. The hits from new detectors improves the Sigma of the q/p_T resolution up to ∼5 -10% as seen in the figure.

Performance plots for PU = 140 sample in 2023 scenario: RMS of q/p_T resolution

RMS_invptres_PU_newscale.pdf

Improvements in the RMS of q/p_T resolution with added redundancy of the upgrade forward muon detectors, for standalone muons, as a function of the simulated η for p_T = 100 GeV at 140 PU. Again the RMS is taken from the histogram of gaussian width of q/p_T plotted in the range of [-6,+6] using association by chi2. The hits from new detectors improves the RMS of the q/p_T resolution up to ∼35% as seen in the figure.

Performance plots for PU = 140 in 2023 scenario: charge mis-identification

* Charge Mis-identification probability

chargemisid_PU_11august.pdf

Improvements in the Charge mis-identification probability with added redundancy of the upgrade forward muon detectors, for standalone muons, as a function of the simulated η for p_T = 100 GeV at 140 PU using association by chi2. In the “2023 scenario” the additional hits from new detectors in track fitting will also improve the muon track resolution and reduce the charge mis-identification probability, which in case of “no upgrade” scenario degrade with 140 PU. We can see from the figure that adding the new detectors improved the charge mis-identification probability up to ∼50%.