# Determining Lepton Sign Mismeasurement Rate from the CMS Detector to Identify Doubly Charged Higgs Boson Decay Background

## Session Number

Project ID: PHYS 30

## Advisor(s)

Dr. Peter Dong, Illinois Mathematics and Science Academy

## Discipline

Physical Science

## Start Date

17-4-2024 10:00 AM

## End Date

17-4-2024 10:15 AM

## Abstract

The doubly charged Higgs Boson is a particle predicted by various theoretical models such as the Type II seesaw model. In assisting the search for possible doubly charged Higgs boson decay, we determine the lepton sign mismeasurement rate of lepton pairs reconstructed near the Z-peak mass to calculate expected background in doubly charged Higgs decay signature detection. We use data from the CMS detector at the LHC in collaboration with Fermilab. The Standard Model has no same sign lepton decay channels, thus all same sign events are the result of combinatorial background and sign mismeasurement. Since identification spikes near the z-peak are mostly misidentified sign lepton pairs, it is useful for estimating the overall rate of lepton sign misidentification in CMS. To do this, we fit the peak in the same sign data and the opposite data, fit the data without the peaks, and compare the difference of their integrals to find the rate of mismeasurement for future extrapolation.

Determining Lepton Sign Mismeasurement Rate from the CMS Detector to Identify Doubly Charged Higgs Boson Decay Background

The doubly charged Higgs Boson is a particle predicted by various theoretical models such as the Type II seesaw model. In assisting the search for possible doubly charged Higgs boson decay, we determine the lepton sign mismeasurement rate of lepton pairs reconstructed near the Z-peak mass to calculate expected background in doubly charged Higgs decay signature detection. We use data from the CMS detector at the LHC in collaboration with Fermilab. The Standard Model has no same sign lepton decay channels, thus all same sign events are the result of combinatorial background and sign mismeasurement. Since identification spikes near the z-peak are mostly misidentified sign lepton pairs, it is useful for estimating the overall rate of lepton sign misidentification in CMS. To do this, we fit the peak in the same sign data and the opposite data, fit the data without the peaks, and compare the difference of their integrals to find the rate of mismeasurement for future extrapolation.