arXiv subjects

M. A. Hernández-Ruíz

Publications and source records attributed to M. A. Hernández-Ruíz.

27 records · Page 2Linked to original sources

arXiv2018

The $μ^+μ^-$ collider to sensitivity estimates on the magnetic and electric dipole moments of the tau-lepton

Using the effective Lagrangian formalism, the anomalous magnetic and electric dipole moments of the tau-lepton in the $μ^{+}μ^{-} \rightarrow μ^{+}γ^{*} γ^{*} μ^{-}\rightarrow μ^{+}τ\barτμ^{-}$ process at the future muon colliders at the $\sqrt{s}=1.5, 3$ and $6$ TeV are investigated. In addition, the bounds at the $95\%$ confidence level on the dipole moments of the tau-lepton using different integrated luminosities are estimated. It is shown that the $μ^{+}μ^{-} \rightarrow μ^{+}γ^{*} γ^{*} μ^{-}\rightarrow μ^{+}τ\barτμ^{-}$ process leads to a remarkable improvement in the existing experimental bounds on the anomalous magnetic and electric dipole moments of the tau-lepton.

hep-ph↗

arXiv2017

Probing the electromagnetic dipole moments of the tau-neutrino in the $U(1)_{B-L}$ model at the ILC and CLIC energies

In this work we study the sensitivity on the anomalous magnetic and electric dipole moments of the tau-neutrino in the framework of the $SU(2)_L\times U(1)_Y\times U(1)_{B-L}$ electroweak model at future $e^+e^-$ linear colliders as the ILC and CLIC. For our study we consider the process $e^{+}e^{-}\rightarrow ( Z, Z', γ) \to ν_τ\bar ν_τγ$. For center-of-mass energies of $\sqrt{s}=1000-3000\hspace{0.8mm}GeV$ and integrated luminosities of ${\cal L}=500-2000\hspace{0.8mm}fb^{-1}$, we derive $95 \% \hspace{1mm}$ C.L. limits on the dipole moments $|μ_{ν_τ}(μ_B)| \leq 6.28 \times 10^{-9}$ and $|d_{ν_τ}(e cm)| \leq 1.21 \times 10^{-21}$ improve the existing limits by two or three orders of magnitude. Our study complements other studies on the dipole moments of the tau-neutrino at hadron and $e^+e^-$ colliders.

hep-ph↗

arXiv2017

Stellar energy loss rates in the pair-annihilation process beyond the standard model

We calculate the stellar energy loss due to neutrino-pair production in $e^+e^-$ annihilation in the context of a 331 model, a left-right symmetric model and a simplest little Higgs model in a way that can be used in supernova calculations. We also present some simple estimates which show that such process can act as an efficient energy loss mechanism in the shocked supernova core. We find that the stellar energy loss is almost independent on the parameters of the models in the allowed range for these parameters. This work complements other studies on the stellar energy loss rate in $e^+e^-$ annihilation.

hep-ph↗

arXiv2004

Limits on the Dipole Moments of the $τ$-Lepton via the Process $e^{+}e^{-}\to τ^+ τ^- γin a Left-Right Symmetric Model

Limits on the anomalous magnetic moment and the electric dipole moment of the $τ$ lepton are calculated through the reaction $e^{+}e^{-}\to τ^+ τ^- γ$ at the $Z_1$-pole and in the framework of a left-right symmetric model. The results are based on the recent data reported by the L3 Collaboration at CERN LEP. Due to the stringent limit of the model mixing angle $ϕ$, the effect of this angle on the dipole moments is quite small.

hep-ph↗

arXiv2003

Higgs Pair-Production in the Standard Model at Next Generation Linear $e^+e^-$ Colliders

We study the Higgs pair-production in the Standard Model of the strong and electroweak interactions at future $e^{+}e^{-}$ collider energies, with the reaction $e^{+}e^{-}\to t \bar t HH$. We evaluated the total cross section of $t\bar tHH$ and calculate the number total of events considering the complete set of Feynman diagrams at tree-level. The numerical computation is done for the energy which is expected to be available at a possible Next Linear $e^{+}e^{-}$ Collider: with center-of-mass energy $800, 1600$ $GeV$ and luminosity 1000 $fb^{-1}$.

hep-ph↗

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↗

arXiv2001

Production of the MSSM Higgs Bosons at Next Generation Linear $e^+e^-$ Colliders

% insert abstract here We study the production of the Higgs bosons predicted in the Minimal Supersymmetric extension of the Standard Model $(h^0, H^0, A^0, H^\pm)$, with the reactions $e^{+}e^{-}\to b\bar b h^0 (H^0, A^0)$, and $e^+e^-\to τ^-\bar ν_τH^+, τ^+ν_τH^-$, using the helicity formalism. We evaluate cross section of $h^0, H^0, A^0$ and $H^\pm$ in the limit when $\tanβ$ is large. The numerical computation is done considering two stages of a possible Next Linear $e^{+}e^{-}$ Collider: the first with $\sqrt{s}=500$ $GeV$ and design luminosity 50 $fb^{-1}$, and the second with $\sqrt{s}=1$ $TeV$ and luminosity 100-200 $fb^{-1}$.

hep-ph↗