arXiv subjects

M. A. Hernandez-Ruiz

Publications and source records attributed to M. A. Hernandez-Ruiz.

18 recordsLinked to original sources

arXiv2020

Stellar energy loss rates beyond the standard model

It is known that the dipole moments of the neutrino lead to important astrophysical and cosmological effects. In this regard, within the context of a $U(1)_{B-L}$ model, we develop and present novel analytical formulas to assess the effects of the anomalous magnetic moment and electric dipole moment of the neutrino on the stellar energy loss rates through some common physical process of pair-annihilation $e^+e^-\to(γ, Z, Z^{\prime})\toν\barν$. Our results show that the stellar energy loss rates strongly depends on the effective magnetic moment of the neutrino, but also on the parameters which characterize the adopted $U(1)_{B-L}$ model.

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arXiv2019

Bounds on the non-standard $W^+W^-γ$ couplings at the LHeC and the FCC-he

We examine the potential of the $e^-p \to e^-γ^*p \to e^-W^-q'X$ ($γ^*$ is Weizsacker-Willams photon) reaction to probe the non-standard $W^+W^-γ$ couplings at the Large Hadron electron Collider (LHeC) and the Future Circular Collider-hadron electron (FCC-he). We find $95\%$ confidence level bounds on the anomalous coupling $Δκ_γ$ and $λ_γ$ parameters in the view of effective Lagrangian approach with various values of the integrated luminosity. We assume center-of-mass energies of the electron-proton system $\sqrt{s}= 1.30, 1.98, 7.07, 10\hspace{0.8mm}{\rm TeV}$ and luminosities ${\cal L} = 10-1000 \hspace{0.8mm}{\rm fb^{-1}}$. The best limits obtained from the process $e^-p \to e^-γ^*p \to e^-W^-q'X$ on the anomalous $Δκ_γ$ and $λ_γ$ couplings are $Δκ_γ= |0.00069|$ and $λ_γ= [-0.0099, 0.0054]$. These bounds show that the process under consideration is a good prospect for the searching of the non-standard $Δκ_γ$ and $λ_γ$ couplings at the LHeC and the FCC-he. In addition, our results provide complementary information on other results for $Δκ_γ$ and $λ_γ$ couplings.

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arXiv2018

Model-independent sensibility studies for the anomalous dipole moments of the $ν_τ$ at the CLIC based $γe^-$ colliders

To improve the theoretical prediction of the anomalous dipole moments of the $τ$-neutrino, we have carried out a study through the process $γe^- \to τ\barν_τν_e$, which represents an excellent and useful option in determination of these anomalous parameters. To study the potential of the process $γe^- \to τ\barν_τν_e$, we apply a future high-energy and high-luminosity linear electron-positron collider, such as the CLIC, with $\sqrt{s}=380, 1500, 3000\hspace{0.8mm}GeV$ and ${\cal L}=10, 50, 100, 200, 500, 1000, 1500, 2000, 3000\hspace{0.8mm}fb^{-1}$, and we consider systematic uncertainties of $δ_{sys}=0, 5, 10\%$. With these elements, we present a comprehensive and detailed sensitivity study on the total cross-section of the process $γe^- \to τ\barν_τν_e$, as well as on the dipole moments $μ_{ν_τ}$ and $d_{ν_τ}$ at the $95\%$ C.L., showing the feasibility of such process at the CLIC at the $γe^-$ mode with unpolarized and polarized electron beams.

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arXiv2018

Model-independent bounds probing on the electromagnetic dipole moments of the $τ$-lepton at the CLIC

We establish model independent bounds on the anomalous magnetic and electric dipole moments of the tau-lepton using the two-photon processes $γγ\to τ^+τ^-$ and $γγ\to τ^+τ^-γ$. We use ${\cal L}=10, 50, 100, 300, 500, 1000, 1500, 2000, 3000 \hspace{0.8mm}fb^{-1}$ of data collected with the future $e^+e^-$ linear collider such as the CLIC at $\sqrt{s}=380, 1500, 3000 \hspace{0.8mm}GeV$ and we consider systematic uncertainties of $δ_{sys}=0, 3, 5\hspace{1mm}\%$. Precise bounds at $95\%$ C. L. on the anomalous dipole moments to the tau-lepton $-0.00015\leq \tilde{a}_τ\leq 0.00017$ and $|\tilde{d}_τ(ecm)|=9.040\times 10^{-19}$ are set from our study. Our results show that the processes under consideration are a very good prospect for probing the dipole moments of the tau-lepton at the future $e^+e^-$ linear collider at the $γγ$ mode.

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arXiv2017

Studies on the anomalous magnetic and electric dipole moments of the tau-neutrino in $pp$ collisions at the LHC

In this paper the production cross section $pp\rightarrow (γ, Z) \to ν_τ\bar ν_τγ+X$ in $pp$ collisions at $\sqrt{s}=8, 13, 14, 33TeV$ is presented. Furthermore, we estimate bounds at the $95\%C. L.$ on the dipole moments of the tau-neutrino using integrated luminosity of ${\cal L}=20, 50, 100, 200, 500, 1000, 3000 fb^{-1}$ collected with the ATLAS detector at the LHC and we consider systematic uncertainties of $δ_{sys}=0, 5, 10\%$. It is shown that the process under consideration is a good prospect for probing the dipole moments of the tau-neutrino at the LHC.

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arXiv2016

Higgs bosons production and decay at future $e^+e^-$ linear colliders as a probe of the B-L model

We study the phenomenology of the light and heavy Higgs boson production and decay in the context of a $U(1)_{B-L}$ extension of the Standard Model with an additional $Z'$ boson at future $e^+e^-$ linear colliders with center-of-mass energies of $\sqrt{s}=500-3000\hspace{0.8mm}GeV$ and integrated luminosities of ${\cal L}=500-2000\hspace{0.8mm}fb^{-1}$. The study includes the processes $e^{+}e^{-}\rightarrow (Z, Z') \to Zh$ and $e^{+}e^{-}\rightarrow (Z, Z') \to ZH$, considering both the resonant and non-resonant effects. We find that the total number of expected $Zh$ and $ZH$ events can reach 909,124 and 97,487, respectively, which is a very optimistic scenario and thus it would be possible to perform precision measurements for both Higgs bosons $h$ and $H$, as well as for the $Z'$ boson in future high-energy and high-luminosity $e^+e^-$ colliders experiments. Our study complements other studies on the B-L model and on the Higgs-strahlung processes $e^{+}e^{-}\rightarrow (Z, Z') \to Zh$ and $e^{+}e^{-}\rightarrow (Z, Z') \to ZH$.

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arXiv2015

$Z'$ resonance and associated $Zh$ production at future Higgs boson factory: ILC and CLIC

We study the prospects of the B-L model with an additional $Z'$ boson to be a Higgs boson factory at high-energy and high-luminosity linear electron positron colliders, such as the ILC and CLIC, through the Higgs-strahlung process $e^{+}e^{-}\rightarrow (Z, Z') \to Zh$, including both the resonant and non-resonant effects. We evaluate the total cross section of $Zh$ and we calculate the total number of events for integrated luminosities of 500-2000\hspace{0.8mm}$fb^{-1}$ and center of mass energies between 500 and 3000\hspace{0.8mm}$GeV$. We find that the total number of expected $Zh$ events can reach $10^6$, which is a very optimistic scenario and it would be possible to perform precision measurements for both the $Z'$ and Higgs boson in future high-energy $e^+e^-$ colliders experiments.

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arXiv2009

Neutral Higgs Boson Pair-Production and Trilinear Self-Couplings in the MSSM at ILC and CLIC Energies

We study pair-production as well as the triple self-couplings of the neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) at the Future International Linear $e^{+}e^{-}$ Collider (ILC) and Compact Linear Collider (CLIC). The analysis is based on the reactions $e^{+}e^{-}\to b \bar b h_ih_i, t \bar t h_ih_i$ with $h_i=h, H, A$. We evaluate the total cross-section for both $b\bar bh_ih_i$, $t\bar th_ih_i$ and calculate the total number of events considering the complete set of Feynman diagrams at tree-level. We vary the triple couplings $κλ_{hhh}$, $κλ_{Hhh}$, $κλ_{hAA}$, $κλ_{HAA}$, $κλ_{hHH}$ and $κλ_{HHH}$ within the range $κ=-1$ and +2. The numerical computation is done for the energies expected at the ILC with a center-of-mass energy 500, 1000, 1600 $GeV$ and a luminosity 1000 $fb^{-1}$. The channels $e^{+}e^{-}\to b \bar b h_ih_i$ and $e^{+}e^{-}\to t \bar t h_ih_i$ are also discussed to a center-of-mass energy of 3 $TeV$ and luminosities of 1000 $fb^{-1}$ and 5000 $fb^{-1}$.

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arXiv2008

Probing the ZZgamma and Zgammagamma Couplings Through the Process e+e- --> nu anti-nu gamma

We study the sensitivity for testing the anomalous triple gauge couplings $ZZγ$ and $Zγγ$ via the process $e^+e^-\to ν\barνγ$ at high energy linear colliders. For integrated luminosities of 500 $fb^{-1}$ and center of mass energies between 0.5 and 1.5 $TeV$, we find that this process can provide tests of the triple neutral gauge boson couplings of order $10^{-4}$, one order of magnitude lower than the standard model prediction.

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arXiv2008

The Triple Higgs Boson Self-Coupling at Future Linear e+e- Colliders Energies: ILC and CLIC

We analyzed the triple Higgs boson self-coupling at future $e^{+}e^{-}$ colliders energies, with the reactions $e^{+}e^{-}\to b \bar b HH, t \bar t HH$. We evaluate the total cross-sections for both $b\bar bHH$ and $t\bar tHH$, and calculate the total number of events considering the complete set of Feynman diagrams at tree-level. We vary the triple coupling $κλ_{3H}$ within the range $κ=-1$ and +2. The numerical computation is done for the energies expected to be available at a possible Future Linear $e^{+}e^{-}$ Collider with a center-of-mass energy $800, 1000, 1500$ $GeV$ and a luminosity 1000 $fb^{-1}$. Our analysis is also extended to a center-of-mass energy 3 $TeV$ and luminosities of 1000 $fb^{-1}$ and 5000 $fb^{-1}$. We found that for the process $e^{+}e^{-}\to b \bar b HH$, the complete calculation differs only by 3% from the approximate calculation $e^{+}e^{-}\to ZHH(Z\to b\bar b)$, while for the process $e^{+}e^{-}\to t \bar tHH$, the expected number of events, considering the decay products of both $t$ and $H$, is not enough to obtain an accurate determination of the triple Higgs boson self-coupling.

hep-ph↗

arXiv2008

Constraints on Left-Right Symmetric and $E_6$ Superstring Models from the Number of Light Neutrino Species

Using the experimental value for the rate $R^{LEP} _{exp}=Γ_{inv}/Γ_{l\bar l}=5.942\pm 0.016$, we derive constraints on the number of light neutrino species with the invisible width method in the framework of a left-right symmetric model (LRSM) and a $E_6$ superstring model as a function of their respective mixing angles for the neutral vector gauge bosons. Using the above LEP result we get the constraints $-1.6\times 10^{-3}\leqϕ\leq 1.1\times 10^{-3}$ and $-1.3\times 10^{-2}\leqϕ_{E_6} \leq 0.4\times 10^{-2}$, which are stronger than those obtained in previous studies of these models.

hep-ph↗

arXiv2007

Limits on the Electromagnetic and Weak Dipole Moments of the Tau-Lepton in E_6 Superstring Models

We obtain limits on the electromagnetic and weak dipole moments of the tau-lepton in the framework of a Left-Right symmetric model (LRSM) and a class of $E_6$ inspired models with an additional neutral vector boson $Z_θ$. Using as an input the data obtained by the L3 and OPAL Collaborations for the reaction $e^+e^-\to τ^+τ^-γ$, we get a stringent limit on the LRSM mixing angle $ϕ$, $-1.66\times 10^{-3}< ϕ<1.22\times 10^{-3}$, which in turn induces bounds on the tau weak dipole moments which are consistent with the bounds obtained recently by the DELPHI and ALEPH Collaborations from the reaction $e^+e^-\to τ^+τ^-$. We also get similar bounds for the weak dipole moments of the tau lepton in the framework of $E_6$ superstring models.

hep-ph↗

arXiv2007

Bounding the Number of Light Neutrinos Species in a Left-Right Symmetric Model

Using the experimental values for the rates $R^{LEP} _{exp}=Γ_{inv}/Γ_{l\bar l}=5.942\pm 0.016$, $R^{Giga-Z_1}=Γ_{inv}/Γ_{l\bar l}=5.942\pm 0.012$ (most conservative) and $R^{Giga-Z_1}=Γ_{inv}/Γ_{l\bar l}=5.942\pm 0.006$ (most optimistic) we derive constraints on the number of neutrinos light species $(N_ν)_{LRSM}$ with the invisible width method in the framework of a left-right symmetric model (LRSM) as a function of the LR mixing angle $ϕ$. Using the LEP result for $N_ν$ we may place a bound on this angle, $-1.6\times 10^{-3}\leqϕ\leq 1.1\times 10^{-3}$, which is stronger than those obtained in previous studies of the LRSM.

hep-ph↗

arXiv2006

Bounding the magnetic and electric dipole moments of tau nu from the process e+e- --> nu bar nu gamma in E6 Superstring Models

We obtain bounds on the anomalous magnetic and electric dipole moments of the tau-neutrino through the reaction $e^{+}e^{-}\to ν\bar νγ$ at the $Z_1$-pole in the framework of a Left-Right symmetric model and a class of $E_6$ inspired models with an additional neutral vector boson $Z_θ$. We use the data collected by the L3 Collaboration at LEP. For the parameters of the $E_6$ model we consider the mixing angle $θ_{E_6}=37.8^o$ and $M_{Z_θ}=7M_{Z_1}$. We find that our bounds are of the same order of magnitude as those obtained in other extensions of the Standard Model.

hep-ph↗

arXiv2006

Studying the Triple Higgs Self-Coupling Via e+e- --> b bar b HH, t bar t HH at Future Linear e+e- Colliders

We study the triple Higgs self-coupling at future $e^{+}e^{-}$ colliders energies, with the reactions $e^{+}e^{-}\to b \bar b HH$ and $e^{+}e^{-}\to t \bar t HH$. We evaluate the total cross section of $b\bar bHH$, $t\bar tHH$ and calculate the total number of events considering the complete set of Feynman diagrams at tree-level. The sensitivity of the triple Higgs coupling is considered in the Higgs mass range 110-190 $GeV$, for the energy which is expected to be available at a possible Next Linear $e^{+}e^{-}$ Collider with a center-of-mass energy $800, 1000, 1500$ $GeV$ and luminosity 1000 $fb^{-1}$.

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arXiv2005

Pairs-Production of Higgs in Association with Bottom Quarks Pairs at $e^+e^-$ Colliders

In a previous paper, we studied the Higgs pair production in the standard model with the reaction $e^{+}e^{-}\to t \bar t HH$. Based on this, we study the Higgs pair production via $e^{+}e^{-}\to b \bar b HH$. We evaluate the total cross section of $b\bar bHH$ and calculate the number total of events considering the complete set of Feynman diagrams at tree-level, and compare this process with the process $e^{+}e^{-}\to t \bar t HH$. The numerical computation is done for the energy which is expected to be available at a possible Next Linear $e^{+}e^{-}$ Collider with a center-of-mass energy $800, 1000, 1600$ $GeV$ and luminosity 1000 $fb^{-1}$.

hep-ph↗

arXiv2004

Bounds on the magnetic moment and electric dipole moment of the $τ$-neutrino via the process $e^{+}e^{-}\to ν\bar νγ$

Bounds on the anomalous magnetic moment and the electric dipole moment of the $τ$-neutrino are calculated through the reaction $e^{+}e^{-}\to ν\bar νγ$ 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. We find that the bounds are almost independent of the mixing angle $ϕ$ of the model in the allowed experimental range for this parameter. In addition, the analytical and numerical results for the cross-section have never been reported in the literature before.

hep-ph↗

arXiv2000

Detecting the MSSM Higgs Bosons at Future $e^+e^-$ Colliders

We investigate the possibility of detecting 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 analyze the region of parameter space $(m_{A^0}-\tanβ)$ where $h^0, H^0, A^0$ and $H^\pm$ could be detected 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 $fb^{-1}$.

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