# $k_T$-factorization approach to the Higgs boson production in $ZZ^*\to 4\ell$ channel at the LHC

## TL;DR

This paper employs the $k_T$-factorization approach to calculate the differential cross section of Higgs boson production in the $ZZ^* o 4 ext{l}$ channel at the LHC, comparing results with experimental data and collinear factorization predictions.

## Contribution

It introduces a $k_T$-factorization calculation for Higgs production in the $ZZ^*$ decay channel using CCFM evolution and off-shell matrix elements, providing a novel comparison with experimental and collinear results.

## Key findings

- Results are close to NNLO+NNLL collinear predictions.
- Calculations agree with experimental measurements at 8 TeV and 13 TeV.
- The approach offers an alternative to collinear factorization for Higgs production.

## Abstract

We calculated a differential cross section of the Higgs boson production in the $h\to ZZ^*\to 4\ell$ decay channel within the framework of $k_T$-factorization. Results are obtained using an off-shell matrix element for the $g^*g^*\to h\to ZZ^*\to 4\ell$ process together with Ciafaloni-Catani-Fiorani-Marchesini (CCFM) evolution equations for an unintegrated gluon distribution function. We have presented a comparison of our results with the latest experimental measurements at $\sqrt{S}$ = 8 TeV and $\sqrt{S}$ = 13 TeV from the ATLAS and CMS collaborations at the LHC. In addition to this, we have compared our results with the results from the collinear factorization formalism calculated up to next-to-next-to-leading order plus next-to-next-to-leading logarithm (NNLO + NNLL) accuracy obtained using the HRes code for the Higgs boson production in the gluon-gluon fusion process. Our estimates are consistently close to NNLO + NNLL results obtained using a collinear factorization formalism and are also in agreement with experimental measurements.