Related papers: On decays of Z' into unparticle stuff
We study the $Z\rightarrow \gamma \bar \gamma$ process in which the $Z$ boson decays into a photon $\gamma$ and a massless dark photon $\bar \gamma$, when the latter couples to standard-model fermions via dipole moments. This is a simple…
We study the decay of the standard model Z boson into unparticle plus a single photon through a one-loop process. As in the anomaly type decay, only the axial-vector part of the Z coupling matching with the vector unparticle and/or the…
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…
We study the decay process of the Z boson to a photon and a graviton. The most general form of the on-shell amplitude, subject to the constraints due to the conservation of the electromagnetic and the energy-momentum tensor, is determined.…
We analyze the $Z$-boson decay $Z\to \gamma\, X$ into a photon ($\gamma$) plus a hypothetical light boson ($X$) belonging to a dark or secluded sector. Due to its feeble interactions with Standard Model fields, this dark boson is behaving…
The well-known Landau-Yang (LY) theorem on the decay of a neutral particle into two photons is generalized for analyzing the decay of a neutral or charged particle into two identical massless particles of any spin. Selection rules…
We study the production of the vector $U$ -unparticle stuff and a single photon in decays of a dilaton. The signals of an unparticle can be detected through the missing energy and momentum distribution carried away by $U$ once it was…
We suggest that Bose statistics for photons can be tested by looking for decays of spin-1 bosons into two photons. The experimental upper limit on the decay $Z \rightarrow \gamma \gamma $ is used to establish for the first time the…
We investigate the rare radiative decays of extra gauge neutral bosons. In particular, we established the theoretical predictions for the production of unparticle in decays of $Z^{\prime}$ - bosons. The implementation of our prediction in…
In extensions of the standard model, light scalar particles are often possible because of symmetry considerations. We study the decay of the Z boson into such particles. In particular, we consider for illustration the scalar sector of a…
We consider the phenomenology of the decay of a Z boson into a photon and a Kaluza-Klein excitation of the graviton in the ADD model. Using LEP data, we obtain an upper bound on the branching ratio corresponding to this process of ~10^-11.…
We study unparticle physics effects in (Lambda_b -> Lambda + missing energy) decay with polarized $\Lambda_b$ and $\Lambda$ baryons. The sensitivity of the branching ratio of this decay and polarizations of (Lambda_b) and (Lambda) baryons…
A multi-Higgs model with an extra neutral gauge boson ($Z'$) is introduced. One scalar Higgs boson ($H_2$) in this model decays dominantly into a photon pair. The $Z'$ decay to $\mu^+\mu^-$ gets a much larger branching ratio than the $Z$…
Yang's theorem states that an initial J=1 state cannot decay into two photons. Because of this result some reactions relating to elementary particles or atomic transitions can be ruled out. The theorem is not valid in the presence of…
We explore the possibility that $Z'$ couplings can be probed using decay modes which involve neutrinos once Standard Model backgrounds are directly determined by the data itself. For some models, sufficient statistics are available at…
We first confirm that Nishijima's method of the $\pi^0 \rightarrow \gamma +\gamma $ calculation can precisely reproduce the observed life time of $\pi^0$ decay. Then, we calculate, for the first time, the T-matrix of the $Z^0 \rightarrow…
A complete study of the one-loop induced decay Z -> neutrino antineutrino photon is presented within the framework of the Standard Model. The advantages of using a nonlinear gauge are stressed. We have found that the main contributions come…
A model of a light $Z'$ boson is constructed and phenomenological bounds are derived. This $Z'$ boson arises from a very simple extension to the Standard Model, and it is constrained to be light because the vacuum expectation values which…
New physics models admit the interesting possibility of a Z' weak boson associated with an extra U(1) gauge symmetry and a Higgs boson that is heavy enough to decay into a pair of Z bosons. Then Z' production and decay via Z' -> ZH -> ZZZ…
In the large extra dimensional ADD scenario, Z bosons undergo a one-loop decay into a photon and Kaluza-Klein towers of gravitons/gravi-scalars. We calculate such a decay width, extending previous arguments about the general form of the…