$KMR$ $k_t$-factorization procedure for the description of the $LHCb$ forward hadron-hadron $Z^0$ production at $\sqrt{s}=13\;TeV$

Abstract

Quit recently, two sets of new experimental data from the $LHCb$ and the $CMS$ collaborations have been published, concerning the production of the $Z^0$ vector boson in hadron-hadron collisions with the center-of-mass energy $E_{CM}= \sqrt{s}=13\;TeV$. On the other hand, in our recent work, we have conducted a set of $NLO$ calculations for the production of the electroweak gauge vector bosons, utilizing the unintegrated parton distribution functions ($UPDF$) in the frameworks of $Kimber$-$Martin$-$Ryskin$ ($KMR$) or $Martin$-$Ryskin$-$Watt$ ($MRW$) and the $k_t$-factorization formalism, concluding that the results of the $KMR$ scheme are arguably better in describing the existing experimental data, coming from $D0$, $CDF$, $CMS$ and $ATLAS$ collaborations. In the present work, we intend to follow the same $NLO$ formalism and calculate the rate of the production of the $Z^0$ vector boson, utilizing the $UPDF$ of $KMR$ within the dynamics of the recent data. It will be shown that our results are in good agreement with the new measurements of the $LHCb$ and the $CMS$ collaborations.