Related papers: Z-Boson Decays in a Strong Electromagnetic Field
Based on the expectation generated by the discovery of new particles by current colliders, we analyze the decay of the Z' boson in the frame of one of the SU(3)L \otimes U(1)N electroweak extensions of the standard model. The main objective…
We compute the decay rates for the processes $Z\to V+\gamma$, where $Z$ is the $Z$ boson, $\gamma$ is the photon, and $V$ is one of the vector quarkonia $J/\psi$ or $\Upsilon(nS)$, with $n=1$, $2$, or $3$. Our computations include…
In this paper, we present an improved calculation for the decay rate of the rare $Z$-boson decay into $J/\psi + J/\psi$. This decay is dominated by the photon fragmentation mechanism, i.e., the transition $Z\to J/\psi + \gamma^{*}$ followed…
A search has been performed for heavy resonances decaying to ZZ or ZW in 2$\ell$2q final states, with two charged leptons ($\ell=$ e,$\mu$) produced by the decay of a Z boson, and two quarks produced by the decay of a W or Z boson. The…
A search for a new heavy scalar resonance decaying to two Z bosons, each subsequently decaying to a pair of electrons or muons, is presented. The results are based on a proton-proton collision data set collected by the CMS experiment at the…
Decays of Z bosons to four charged leptons (electrons and muons) are studied in proton-proton collisions at $\sqrt{s}$ = 8 and 13 TeV. The analysis is based on data collected with the CMS detector at the LHC corresponding to an integrated…
Observing a heavy charged Higgs boson produced in the near future at the Tevatron or at the LHC would be instant evidence of physics beyond the Standard Model. Whether such a Higgs boson would be supersymmetric or not it could only be…
A search for Z boson decays to pairs of b-quark jets has been performed in the full dataset collected with the CDF detector at the Tevatron proton-antiproton collider. After the selection of a pure sample of bb events by means of the…
The width of the neutrino decay into the electron and $W$ boson in a strong external magnetic field is obtained from the imaginary part of the neutrino self-energy. This result corrects the formulae existing in the literature. The mean free…
The first observation of the Z boson decaying to four leptons in proton-proton collisions is presented. The analyzed data set corresponds to an integrated luminosity of 5.02 inverse femtobarns at sqrt(s) = 7 TeV collected by the CMS…
We examine the decay of $Z_1$ in electrons with recent data from LEP. The partial width $\Gamma(Z_1\to e^-e^+)$ is studied in the framework of a left-right symmetric model with standard electroweak corrections. Processes measured near the…
We have performed a one-loop calculation of the width of the rare decay H -> Z Z \gamma in the standard model for Higgs boson masses 190 GeV \leq m_H \leq 250 GeV. We find that the most dominant helicity combinations for the Z bosons and…
We discuss the very rare, exclusive hadronic decays of a Z boson into a meson and a photon. The QCD factorization approach allows to organize the decay amplitude as an expansion in powers of $\Lambda_{\rm QCD}/m_Z\,$, where the leading…
This article presents results for the last unknown two-loop contributions to the $Z$-boson partial widths and $Z$-peak cross-section. These are the so-called bosonic electroweak two-loop corrections, where "bosonic" refers to diagrams…
We study the decay of a Z' boson into two Z bosons by extending the Landau-Yang theorem to a parent particle decaying into two Z bosons. For a spin-1 parent the theorem predicts: 1) there are only two possible couplings and 2) the…
The radiative decay of the axion $a \to \gamma \gamma$ is investigated in an external electromagnetic field in DFSZ model in which axion couples to both quarks and leptons at tree level. The decay probability is strongly catalyzed by the…
The question of classical topological stability of the gauge vortex defects is reanalyzed upon taking into account the quantum perturbative effects. The purely Abelian Higgs string remains stable while the coupling of the effectively…
Massive leptophobic Z' bosons decaying to a pair of charginos are searched for in proton-proton collisions at $\sqrt{s}$ = 13 TeV, using data samples collected by the CMS experiment in 2016, 2017, and 2018, corresponding to a total…
We calculate the electroweak and finite width corrections to the decay of an unpolarized top quark into a bottom quark and a $ W $-gauge boson where the helicities of the $ W $ are specified as longitudinal, transverse-plus and…
Motivated by recent results from Higgs searches at the Large Hadron Collider, we consider possibilities to enhance the diphoton decay width of the Higgs boson over the Standard Model expectation, without modifying either its production rate…