Improved $b$-jet Energy Correction for $H \to b\bar{b}$ Searches at CDF

TL;DR

This paper introduces a new method to improve b-jet energy resolution by combining multiple detector measurements, leading to better Higgs mass resolution and increased sensitivity in Higgs boson searches at CDF.

Contribution

A novel correction function that enhances b-jet energy measurement accuracy by integrating secondary vertex, tracking, and calorimeter data, improving Higgs search sensitivity.

Findings

Improved the Higgs dijet invariant mass resolution from ~15% to ~11%.

Achieved a ~9% increase in expected Higgs search sensitivity.

Enhanced b-jet energy resolution in Monte Carlo simulations.

Abstract

We present a method for improving the $b$-jet energy resolution in order to improve the signal sensitivity in searches for particles decaying to a $b$ quark and anti-$b$ quark. A correction function is computed for individual jets, which combines information from the secondary vertex tagger, the offline tracking and standard calorimeter-based jet-energy reconstruction algorithm in order to provide a more accurate measurement of the true $b$-quark energy. We apply the correction to Monte-Carlo-simulated jets in the process $WH \rightarrow \ell \nu b\bar b$ and find an improvement in both the mean and the resolution of the $b$-jet energy with respect to the $b$-quark energy. The correction improves the measured Higgs dijet invariant mass resolution from $\sim$ 15%(standard jet corrections) to $\sim$ 11%(improved jet corrections) in the Higgs mass range from 100 GeV/$c^2$ - 150 GeV/$c^2$. Using the corrected $b$-jet energies instead of the standard calorimeter-based $b$-jet energies results in a $\sim$ 9% improvement in the expected sensitivity for Higgs boson production cross section in the most sensitive search region of the $WH \rightarrow \ell \nu b\bar b$ analysis, which is two tagged jets and one charged central lepton.