Measurement of the ZZ production cross section and search for anomalous couplings in 2ℓ2ℓ′ final states in pp collisions at $ \sqrt{s}=7 $ TeV

Abstract

A measurement is presented of the ZZ production cross section in the ZZ → 2 2 decay mode with = e, µ and = e, µ, τ in proton-proton collisions at √ s = 7 TeV with the CMS experiment at the LHC. Results are based on data corresponding to an integrated luminosity of 5.0 fb

On polarization parameters of spin-1 particles and anomalous couplings in $$e^+e^-\rightarrow ZZ/Z\gamma $$ e + e - → Z Z / Z γ

“…For finding the best and simultaneous limit on anomalous couplings, we have performed a likelihood mapping using the MCMC method and the obtained limits are listed in Tables 7 and 10 for Z Z and Z γ processes, respectively. For the Z Z process, the ILC ( √ŝ = 500 GeV, L = 100 fb −1 ) limits are tighter than the available LHC ( √ŝ = 7 TeV, L = 5 fb −1 ) limits [40], while the ILC limits on the Z γ anomalous couplings are slightly weaker than the available LHC ( √ŝ = 8 TeV, L = 19.6 fb −1 ) limits [44]. The LHC probes the interactions at large energies and transverse momentum, where the sensitivity to the anomalous couplings is enhanced.…”

“…(1) has been explored at the LEP [32][33][34][35][36], the Tevatron [37][38][39], and the LHC [40][41][42][43][44]. The tightest bounds on f V i (i = 4, 5) [40] and on h V j ( j = 3, 4) [44] comes from the CMS collaboration (see Table 1).…”

“…(1) has been explored at the LEP [32][33][34][35][36], the Tevatron [37][38][39], and the LHC [40][41][42][43][44]. The tightest bounds on f V i (i = 4, 5) [40] and on h V j ( j = 3, 4) [44] comes from the CMS collaboration (see Table 1). For the Z Z process the total rate has been used [40], while for the Z γ process both the cross section and the p T distribution of γ has been used [41][42][43][44] for obtaining the limits.…”

“…The tightest bounds on f V i (i = 4, 5) [40] and on h V j ( j = 3, 4) [44] comes from the CMS collaboration (see Table 1). For the Z Z process the total rate has been used [40], while for the Z γ process both the cross section and the p T distribution of γ has been used [41][42][43][44] for obtaining the limits. All these analyses vary one parameter at a time to find the 95 % confidence limits on the form factors.…”

Next-to-leading order electroweak corrections to $p p \rightarrow \mu^+ \mu^-e^+e^- + X$ at the LHC Collider

“…The µ + µ − e + e − final state has also been used at Run I both by ATLAS and CMS to measure the cross section of Z-boson pair production [1,2,3] and to derive limits on anomalous triple gauge-boson couplings [4,5]. So far, all these measurements are in agreement with the predictions of the SM.…”