arXiv subjects

M. Maya

Publications and source records attributed to M. Maya.

7 recordsLinked to original sources

arXiv2003

Pair Production and Angular Distribution of Helicity Flipped Neutrinos in a Left-Right Symmetric Model

We assume that a massive Dirac neutrino is characteized by two phenomenological parameters, a magnetic moment, and a charge radius, and we calculate the cross-section of the scattering $e^+e^-\to ν\bar ν$ in a left-right symmetric model. We also analyze the angular distribution of the neutrino (antineutrino) with respect to the original direction of the electron (positron) to different state of helicity of the neutrino. We find that the favored directions for the neutrino (antineutrino) with respect to the electron (positron) is forward $(θ=0)$ and backward $(θ= π)$, and is not very probable in the perpendicular direction $(θ= \fracπ{2})$. The calculation is for $ϕ= -0.005$ and $M_{Z_2}=500$ $GeV$, parameters of the Left-Right symmetric model.

hep-ph↗

arXiv2001

Neutron Beta Decay in a Left-Right Symmetric Model

We start from a Left-Right Symmetric Model and we analyze the beta decay of the free neutron $n\to p+e^{-}+\barν_{e}$. We applied this model to incorporate the right currents, whereby we propose an amplitude whose leptonic part contains the parameter $λ$ defined as left-right asymmetry parameter which measures the parity violation. The analysis consists of seeing how the spectrum of energy of the electrons, the total rate of decay, and the lifetime $τ$ of the neutron are affected by the left-right asymmetry parameter, besides taking into account corrections of mass, that is, $m_{e}\neq 0$, $m_{p}\neq m_{n}$, and the recoil of the proton.

hep-ph↗

arXiv2001

Elastic neutrino-electron scattering and effective couplings $(g^{νe}_V)_{LRSM}$ and $(g^{νe}_A)_{LRSM}$ in a Left-Right symmetric model

We start from a Left-Right Symmetric Model with massive Dirac neutrinos, with an electromagnetic structure that consists of a charge radius, and we calculate the cross-section of the scattering $ν_μe^-\to ν_μe^-$. Subsequently, we calculate the simultaneous contribution of the charge radius, of the additional $Z_{2}$ heavy gauge boson and of the mixing angle $ϕ$ parameter of the model at the constants of couplings $(g^{νe}_{V})_{LRSM}$ and $(g^{νe}_{A})_{LRSM}$.

hep-ph↗

arXiv1998

A Direct Constraint on Dimension-Eight Operators from Z-->neutrino antinetrino gamma

We study the radiative decay Z-->neutrino antineutrino gamma whitin an effective Lagrangian approach. Using the search for energetic single-photon events in the data collected by the L3 collaboration, we get direct bounds on the dimension-six and the dimension-eight operators associated with the tau-neutrino magnetic moment and the anomalous electromagnetic properties of the Z boson. As a by-product of our calculation, we reproduce the L3 result for the bound on the tau-neutrino magnetic moment.

hep-ph↗

arXiv1996

The Number of Neutrinos and the Left-Right Symmetric Model

The meaning of $N_ν$ in the Left-Right Symmetric Model (LRSM) is discussed. In its original definition $N_ν$ is the number of neutrinos or generations of leptons, so, in the Standard Model its value is three. However the determination of $N_ν$ in experiments and in astrophysical observations is subject to different theoretical interpretations. We present arguments that gives $N_ν$ as a parameter of the LRSM. Using an experimental value for the rate $Gamma_{inv}/Gamma_{l\bar{l}}$ we calculate the bound $2.90\leq N_{ν_LR}\leq 3.04$ (90 % C. L.), where $N_{ν_LR}$ is a function of the left-right mixing angle $ϕ$. This range is less restrictive than the one of the standard model.

hep-ph↗

arXiv1995

Update to the Neutrino-Electron Scattering in Left-Right Symmetric Models

In a previous paper we study the neutrino-electron scattering in the framework of a left-right symmetric model (LRSM). Constraints on the LRSM parameters $M_{Z_{2}}$ and $ϕ$ were obtained. Based on new measurements we present an update to these constraints and also include in the calculation the radiative corrections.

hep-ph↗

arXiv1995

Constraints on Z1-Z2 Mixing from the Decay $Z1 \to e-e+$ in the left-right Symmetric Model

We examine the decay of $Z_1$ in electrons with recent data from LEP. The partial width $Γ(Z_1\to e^-e^+)$ is studied in the framework of a left-right symmetric model with standard electroweak corrections. Processes measured near the resonance has served to measure the neutral coupling constants very precisely, which is useful to set bounds on the parameters of the model. This partial decay occurs in the resonance zone. As a consecuence the process is independent of the mass of the additional $Z_2$ heavy gauge boson which appears in this kind of models and so we have the mixing angle $\f$ between the left and the right bosons as the only additional parameter. In this paper we take advantage of this fact to set a bound for $\f$: $-9\times 10^{-3}\leq\f\leq 4\times 10^{-3}$, which is in agreement with other constraints previously reported.

hep-ph↗