Electroweak physics and long-lived particles at LHCb

TL;DR

This paper presents LHCb's recent measurements of electroweak bosons and top quarks, along with searches for dark sector mediators, providing new insights into Standard Model precision tests and beyond.

Contribution

It reports the first measurements of W and top quark production cross-sections and charge asymmetries at LHCb, and discusses recent BSM searches for axion-like particles and heavy neutral leptons.

Findings

First measurements of W and top quark production at LHCb

Complementary constraints on parton distribution functions

Results on axion-like particles and heavy neutral leptons searches

Abstract

Extensions of the Standard Model (SM) of Particle Physics can be probed either through precision measurements of SM observables or via direct searches for processes beyond the SM (BSM). This proceeding focuses on precision measurements in the electroweak sector, in particular the properties of the $Z$ boson, $W$ boson and top quark. Measurements of the $W$ and $t$ production cross-sections, as well as charge asymmetries, with an integrated luminosity of 5.1 and 5.4 fb$^{-1}$ of $pp$ collisions collected by the LHCb experiment, are presented for the first time. In consequence of the forward coverage of the LHCb detector, these results provide complementary probes on parton distribution functions compared to measurements performed at central rapidity. Well-motivated BSM candidates include mediators between the visible and dark sectors. In this context, recent results from searches for axion-like particles and heavy neutral leptons are also discussed.