PT Journal
AU ATLAS Collaboration (Aad, Gea
   Amos, KR
   Aparisi Pozo, JA
   Bailey, AJ
   Bouchhar, N
   Cabrera Urban, S
   Cantero, J
   Cardillo, F
   Castillo Gimenez, V
   Chitishvili, M
   Costa, MJ
   Didenko
   Escobar, C
   Fiorini, L
   Fullana Torregrosa, E
   Fuster, J
   Garcia, C
   Garcia Navarro, JE
   Gomez Delegido, AJ
   Gonzalez de la Hoz, S
   Gonzalvo Rodriguez, GR
   Guerrero Rojas, JGR
   Higon-Rodriguez, E
   Lacasta, C
   Lozano Bahilo, JJ
   Marti-Garcia, S
   Martinez Agullo, P
   Miralles Lopez, M
   Mitsou, VA
   Monsonis Romero, L
   Moreno Llacer, M
   Munoz Perez, D
   Navarro-Gonzalez, J
   Poveda, J
   Prades Ibañez, A
   Rubio Jimenez, A
   Ruiz-Martinez, A
   Sabatini, P
   Salt, J
   Sanchez Sebastian, V
   Sayago Galvan, I
   Senthilkumar, V
   Soldevila, U
   Sanchez, J
   Torro Pastor, E
   Valero, A
   Valls Ferrer, JA
   Varriale, L
   Villaplana Perez, M
   Vos, M
TI Observation of gauge boson joint-polarisation states in W± Z production from pp collisions at √s=13 TeV with the ATLAS detector
SO Physics Letters B
JI Phys. Lett. B
PY 2023
BP 137895
EP 27pp
VL 843
DI 10.1016/j.physletb.2023.137895
LA English
AB Measurements of joint-polarisation states of Wand Zgauge bosons in W +/- Z production are presented. The data set used corresponds to an integrated luminosity of 139fb(-1) of proton-proton collisions at a centre-of-mass energy of 13TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. The W +/- Z candidate events are reconstructed using leptonic decay modes of the gauge bosons into electrons and muons. The simultaneous pair-production of longitudinally polarised vector bosons is measured for the first time with a significance of 7.1 standard deviations. The measured joint helicity fractions integrated over the fiducial region are f(00)= 0.067 +/- 0.010, f(0T) = 0.110 +/- 0.029, f(T0) = 0.179 +/- 0.023 and f(TT) = 0.644 +/- 0.032, in agreement with the next-to-leading-order Standard Model predictions. Individual helicity fractions of the Wand Zbosons are also measured and found to be consistent with joint helicity fractions within the expected amounts of correlation. Both the joint and individual helicity fractions are also measured separately in W+Z and W-Z events. Inclusive and differential cross sections for several kinematic observables sensitive to polarisation are presented.
ER