Related papers: S-Matrix Approach to the $Z$ Line Shape
The $Z^0 \to b\bar b$ width, $\Gamma_b$, is analysed in conjunction with the total and hadronic $Z^0$ widths, $\Gamma_T$ and $\Gamma_h$. Assuming, tentatively, that the present 2$\sigma$ discrepancy in $\Gamma_b$ will substantiate as time…
The measurements performed at LEP and SLC have substantially improved the precision of the test of the Minimal Standard Model. The precision is such that there is sensitivity to pure weak radiative corrections. This allows to indirectly…
We present a complete analysis of the one loop electroweak corrections to $e^-e^+\to\gamma\gamma, ~Z\gamma, ~ZZ$ in the Standard (SM) and the Minimal Supersymmetric Standard Model (MSSM). Analytic expressions are written for the…
We present results on the production of jets of particles in association with a $Z/\gamma^*$ boson, in proton-proton collisions at $\sqrt{s} = 7$ TeV with the ATLAS detector at the LHC. The analysis includes the full 2010 data set,…
Standard Model $ZZ$ production is an important background for many searches at the LHC, especially in final states with missing transverse momentum. In this article, boson substitution is applied to estimate $ZZ \rightarrow \ell^+ \ell^-…
A measurement of the t t-bar production cross section at sqrt(s) = 13 TeV is presented using proton-proton collisions, corresponding to an integrated luminosity of 2.2 inverse femtobarns, collected with the CMS detector at the LHC. Final…
The production of Z boson pairs in proton-proton (pp) collisions, pp $\to$ (Z/$\gamma^*$)(Z/$\gamma^*$) $\to$ 2$\ell$ 2$\ell'$, where $\ell,\ell'$ = e or $\mu$, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the…
Differential cross sections for $\gamma p \to K^+\Lambda(1405)$ and $\gamma p \to K^+\Sigma^0(1385)$ reactions have been measured in the photon energy range from 1.5 to 2.4 GeV and the angular range of $0.8<\cos(\Theta)<1.0$ for the $K^+$…
The exclusive production of proton-antiproton pairs in the collisions of two quasi-real photons has been studied using data taken at sqrt(s_ee) = 183 GeV and 189 GeV with the OPAL detector at LEP. Results are presented for proton-antiproton…
It is shown how to construct exactly gauge-invariant S-matrix elements for processes involving unstable gauge particles such as the $Z^0$ boson. The results are applied to derive a physically meaningful expression for the cross-section…
The cross section of the process e+e- -> Ze+e is measured with 0.7fb^-1 of data collected with the L3 detector at LEP. Decays of the Z boson into quarks and muons are considered at centre-of-mass energies ranging from 183GeV up to 209GeV.…
We perform a numerical calculation of the total cross section $\sigma(e^+e^- \rightarrow W^+W^-)$ as a function of energy, taking into account the finite width of the $W$ and the most important radiative corrections. We present these…
Proceeding for LHCP2017 conference. Referencing the paper of JHEP07(2017)107
We present experimental sensitivity for the production of a fourth-generation Majorana neutrino ($N$) via an s-channel $Z$ boson $Z\to NN \to W\ell W\ell$ at hadron colliders. This channel has not been studied for the Tevatron dataset with…
We use the matrix product state formalism to construct stationary scattering states of elementary excitations in generic one-dimensional quantum lattice systems. Our method is applied to the spin-1 Heisenberg antiferromagnet, for which we…
Based on a simplified model including a singlet vector-like top quark $T$ with charge $|Q|=2/3$, we analyze the prospects of observing $T$ via the single $T$ production in the $tZ$ channel with $Z$ decaying to neutrinos at the hadron-hadron…
We study the processes $p\bar{p} \rightarrow WZ \rightarrow \ell\nu\ell^+\ell-$ and $p\bar{p} \rightarrow ZZ \rightarrow \ell^+\ell^-\nu\bar{\nu}, where $\ell$ = $e$ or ${\mu}$. Using 8.6 fb$^{-1} of integrated luminosity collected by the…
We establish the model-independent spin structure of the matrix elements for the near-threshold scalar meson production in $pp-$ and $np$-collisions, when the final particles are emitted in S-state. Polarization phenomena are derived in a…
The first measurement of the electroweak production cross section of a Z boson with two jets (Zjj) in pp collisions at sqrt(s) = 7 TeV is presented, based on a data sample recorded by the CMS experiment at the LHC with an integrated…
We calculate e+e- --> stop/stop/Z at a linear collider. For large splitting between the two stops the cross-section is sensitive to the value of m(stop2) when this particle is too heavy to be directly produced. The results are compared to…