Studies of the energy dependence of diboson polarization fractions and the Radiation Amplitude Zero effect in WZ production with the ATLAS detector

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: ATLAS Collaboration
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929548640124928
author ATLAS Collaboration
author_facet ATLAS Collaboration
contents This Letter presents the first study of the energy-dependence of diboson polarization fractions in $WZ \rightarrow \ellν\ell'\ell'~(\ell, \ell'=e, μ)$ production. The data set used corresponds to an integrated luminosity of 140 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector. Two fiducial regions with an enhanced presence of events featuring two longitudinally-polarized bosons are defined. A non-zero fraction of events with two longitudinally-polarized bosons is measured with an observed significance of 5.2 standard deviations in the region with $100<p_T^Z\leq200$ GeV and 1.6 standard deviations in the region with $p_T^Z>200$ GeV, where $p_T^Z$ is the transverse momentum of the $Z$ boson. This Letter also reports the first study of the Radiation Amplitude Zero effect. Events with two transversely-polarized bosons are analyzed for the $ΔY(\ell_W Z)$ and $ΔY(WZ)$ distributions defined respectively as the rapidity difference between the lepton from the $W$ boson decay and the $Z$ boson and the rapidity difference between the $W$ boson and the $Z$ boson. Significant suppression of events near zero is observed in both distributions. Unfolded $ΔY(\ell_W Z)$ and $ΔY(WZ)$ distributions are also measured and compared to theoretical predictions.
format Preprint
id arxiv_https___arxiv_org_abs_2402_16365
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Studies of the energy dependence of diboson polarization fractions and the Radiation Amplitude Zero effect in WZ production with the ATLAS detector
ATLAS Collaboration
High Energy Physics - Experiment
This Letter presents the first study of the energy-dependence of diboson polarization fractions in $WZ \rightarrow \ellν\ell'\ell'~(\ell, \ell'=e, μ)$ production. The data set used corresponds to an integrated luminosity of 140 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector. Two fiducial regions with an enhanced presence of events featuring two longitudinally-polarized bosons are defined. A non-zero fraction of events with two longitudinally-polarized bosons is measured with an observed significance of 5.2 standard deviations in the region with $100<p_T^Z\leq200$ GeV and 1.6 standard deviations in the region with $p_T^Z>200$ GeV, where $p_T^Z$ is the transverse momentum of the $Z$ boson. This Letter also reports the first study of the Radiation Amplitude Zero effect. Events with two transversely-polarized bosons are analyzed for the $ΔY(\ell_W Z)$ and $ΔY(WZ)$ distributions defined respectively as the rapidity difference between the lepton from the $W$ boson decay and the $Z$ boson and the rapidity difference between the $W$ boson and the $Z$ boson. Significant suppression of events near zero is observed in both distributions. Unfolded $ΔY(\ell_W Z)$ and $ΔY(WZ)$ distributions are also measured and compared to theoretical predictions.
title Studies of the energy dependence of diboson polarization fractions and the Radiation Amplitude Zero effect in WZ production with the ATLAS detector
topic High Energy Physics - Experiment
url https://arxiv.org/abs/2402.16365