CMS-PAS-FTR-18-038 | ||
Prospects for the measurement of electroweak and polarized $\mathrm{WZ} \rightarrow 3\ell\nu$ production cross sections at the High-Luminosity LHC | ||
CMS Collaboration | ||
December 2018 | ||
Abstract: Prospects for the measurement of WZ electroweak (EW) production in association with two jets at the High-Luminosity LHC are presented. The W and Z bosons are detected via their decays, $\mathrm{W}\rightarrow \mathrm{e}\nu$, $\mu\nu$ and $\mathrm{Z\rightarrow ee}$, $\mu\mu$. The results are obtained by a projection of existing results at 13 TeV to 14 TeV. The expected uncertainty in the EW WZ cross section measurement and significance of the observation of the polarized portion of the EW WZ cross section are presented. | ||
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; |
Figures | |
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Figure 1:
The $m_{jj}$ distributions in bins of $\Delta R_{jj}$ for 3000 fb$^{-1}$. |
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Figure 2:
The uncertainty in the EW WZ cross section measurement as a function of integrated luminosity. |
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Figure 3:
Graphs of unrolled 2D $\Delta R_{jj};m_{jj}$ distribution of EW WZ. Left is a ratio of the LL portion of the EW WZ to the total sample and right is a stack plot of the LL portion (seen as signal) to the non-LL portion. |
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Figure 3-a:
Graph of unrolled 2D $\Delta R_{jj};m_{jj}$ distribution of EW WZ: ratio of the LL portion of the EW WZ to the total sample. |
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Figure 3-b:
Graph of unrolled 2D $\Delta R_{jj};m_{jj}$ distribution of EW WZ: stack plot of the LL portion (seen as signal) to the non-LL portion. |
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Figure 4:
The expected significance to observe the LL portion of the EW WZ process as a function of luminosity. |
Tables | |
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Table 1:
Summary of event selection requirements. |
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Table 2:
Expected signal and background yields for 3000 fb$^{-1}$, based on projection of corresponding yields from Ref. [1] and input systematic uncertainties as described in the text. |
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Table 3:
Input systematic uncertainty (%) for each nuisance parameter used in the fit. |
Summary |
The results presented in this note used the projection of existing Run 2 results at 13 TeV to estimate the uncertainty in the EW WZ measurement and to explore a possibility to measure the longitudinal part of the EW WZ cross section at the HL-LHC. The accuracy of the EW WZ cross section measurement is expected to significantly improve, down to 3-5% at 3000 fb$^{-1}$ of the integrated luminosity. The measurement of the LL polarized component of the EW WZ process will require improved analysis techniques, such as machine learning, or combining with results from additional WZ decay channels or other EW VBS measurements. |
References | ||||
1 | CMS Collaboration | Measurement of electroweak WZ production and search for new physics in pp collisions at sqrt(s) = 13 TeV | CMS-PAS-SMP-18-001 | CMS-PAS-SMP-18-001 |
2 | DELPHES 3 Collaboration | DELPHES 3, A modular framework for fast simulation of a generic collider experiment | JHEP 02 (2014) 057 | 1307.6346 |
3 | CMS Collaboration | The CMS Experiment at the CERN LHC | JINST 3 (2008) S08004 | CMS-00-001 |
4 | CMS Collaboration | Technical Proposal for the Phase-II Upgrade of the CMS Detector | CMS-PAS-TDR-15-002 | CMS-PAS-TDR-15-002 |
5 | CMS Collaboration | The Phase-2 Upgrade of the CMS Tracker | CDS | |
6 | CMS Collaboration | The Phase-2 Upgrade of the CMS Barrel Calorimeters Technical Design Report | CDS | |
7 | CMS Collaboration | The Phase-2 Upgrade of the CMS Endcap Calorimeter | CDS | |
8 | CMS Collaboration | The Phase-2 Upgrade of the CMS Muon Detectors | CDS | |
9 | CMS Collaboration | CMS Phase-2 Object Performance | ||
10 | CMS Collaboration | Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV | JINST 13 (2018) P05011 | CMS-BTV-16-002 1712.07158 |
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Compact Muon Solenoid LHC, CERN |
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