Speaker
Description
We study the collider phenomenology of the $B$-$L$ extension of the Standard Model (BLSM), focusing on the production and decay of a heavy neutral gauge boson (( Z' )) at the Large Hadron Collider (LHC). In this framework, the ( Z' ) can decay into pairs of heavy right-handed neutrinos (( \nu_R )), which subsequently decay into charged leptons and ( W ) bosons. These processes give rise to three distinctive final states: (i) two leptons plus four jets (( 2\ell + 4j )), (ii) four leptons plus missing transverse energy (( 4\ell + \text{MET} )), and (iii) three leptons plus two jets and MET (( 3\ell + 2j + \text{MET} )).
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To enhance signal sensitivity and suppress Standard Model backgrounds, we employ multivariate analysis techniques based on Boosted Decision Trees (BDTs), as well as selection optimizations using the \texttt{XGBOOST} framework. The classifiers are trained on kinematic observables sensitive to the masses of the ( Z' ) and ( \nu_R ). We demonstrate that all three final states offer significant discovery potential for both the ( Z' ) and heavy ( \nu_R ) at the High-Luminosity LHC. Our results highlight the testability of the BLSM at current and future collider experiments, and provide a promising avenue for probing the origin of neutrino masses and the baryon asymmetry of the Universe.
