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A. Gutierrez-Rodriguez

Publications and source records attributed to A. Gutierrez-Rodriguez.

At least 19 recordsLinked to original sources

Radiative decays of the 1$P$, 1$D$, 2$S$, and 2$P$ $\Lambda_c$ and 1$D$, 2$S$, and 2$P$ $\Xi_c$ charmed baryons

We analyze the radiative decays of the the 1$P$, 1$D$, 2$S$, and 2$P$ $\Lambda_c$ and 1$D$, 2$S$, and 2$P$ $\Xi_c$ charmed baryons, which belong to the flavor anti-triplet ($\bf {\bar 3}_{\rm F}$), using the constituent quark model. We compute electromagnetic transitions from ground and $P$-wave states to ground states, as well as from second-shell states to both ground and $P$-wave final states. Electromagnetic decay widths are especially valuable for identifying resonances when multiple states share the same mass and total decay width. We give branching ratios which can confirm the assignment of the $\Xi_c(3055)$ reported by LHCb. We also give branching ratios that can support the assignment of the $\Xi_c(3080)$, and discuss the possibilities for the $\Xi_c(3080)$ to be the 1$D$ state with $J^P=5/2^{+}$ or the 2$S$ with $J^P=1/2^{+}$. For the first time, this work provides calculations of electromagnetic decays for $D_\rho$-wave states, $\rho-\lambda$ mixed configurations, and $\rho$-mode radially excited states in singly charmed baryons of the flavor anti-triplet. Both experimental and model-dependent uncertainties are taken into account throughout our analysis.

hep-ph

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.

hep-ph

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.

hep-ph

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.

hep-ph

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.

hep-ph

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.

hep-ph

Bounds on the electromagnetic dipole moments through the single top production at the CLIC

We obtain bounds on the anomalous magnetic and electric dipole moments of the $t$-quark from a future high-energy and high-luminosity linear electron positron collider, such as the CLIC, with unpolarized and polarized electron beams which are a powerful tool to determine new physics. We consider the processes $γe^- \to \bar t bν_e$ ($γ$ is the Compton backscattering photon) and $e^+e^- \to e^-γ^* e^+ \to \bar t bν_e e^+$ ($γ^*$ is the Weizsacker-Williams photon) which are one of the most important sources of single top quark production. For the systematic uncertainties of $δ_{sys}=0\%,\hspace{1mm}5\%$, $b-\mbox{tagging efficiency}=0.8$, center-of-mass energy of $\sqrt{s}=3\hspace{0.8mm}TeV$, integrated luminosity of ${\cal L}=2\hspace{0.5mm}ab^{-1}$ and $2σ\hspace{1mm}(3σ)$ C.L. the future $e^+e^-$ collider may put bounds on the electromagnetic dipole moments $\hat a_V$ and $\hat a_A$ of the top quark of the order of ${\cal O}(10^{-2}-10^{-1})$, which are highly competitive with those recently reported in previous studies.

hep-ph

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 $e^{+}e^{-}\rightarrow (Z, Z') \to ZH$.

hep-ph

$Z'$ 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.

hep-ph

Limits on the quartic couplings $Zγγγ$ and $ZZγγ$ from $e^+e^-$ colliders

We obtain limits on the quartic neutral gauge bosons couplings $Zγγγ$ and $ZZγγ$ using LEP 2 data published by the L3 Collaboration on the reactions $e^+e^-\to γγγ, Zγγ$. We also obtain $95 \%$ C. L. limits on these couplings at the future linear colliders energies. The LEP 2 data induce limits of order $10^{-5}$ $GeV^{-4}$ for the $Zγγγ$ couplings and of order $10^{-3}$ $GeV^{-2}$ for the $ZZγγ$ couplings, which are still above the respective Standard Model predictions. Future $e^+e^-$ linear colliders may improve these limits by one or two orders of magnitude.

hep-ph

Bounds on the dipole moments of the tau-neutrino via the process $e^{+}e^{-}\rightarrow ν\bar νγ$ in a 331 model

We obtain limits on the anomalous magnetic and electric dipole moments of the $ν_τ$ through the reaction $e^{+}e^{-}\rightarrow ν\bar νγ$ and in the framework of a 331 model. We consider initial-state radiation, and neglect $W$ and photon exchange diagrams. The results are based on the data reported by the L3 Collaboration at LEP, and compare favorably with the limits obtained in other models, complementing previous studies on the dipole moments.

hep-ph

Higgs Boson Self-Coupling at High Energy $γγ$ Collider

We analyzed the double production and the triple self-coupling of the standard model Higgs boson at future $γγ$ collider energies, with the reactions $γγ\rightarrow f \bar f HH$ $(f=b, t)$. We evaluated the total cross section for $f\bar fHH$ and calculated the total number of events considering the complete set of Feynman diagrams at tree-level and for different values of the triple coupling $κλ_{HHH}$. We have also analyzed the sensitivity for the considered reaction and we show the results as 95% C.L. regions in the $κ-M_H$ plane for different values of the center of mass energy and different levels of background. The numerical computation was done for the energies which are expected to be available at a possible Future Linear $γγ$ Collider with a center-of-mass energy 500-3000 $GeV$ and luminosities of 1 and $5 ab^{-1}$. We found that the number of events for the process $γγ\rightarrow t \bar t HH$, taking into account the decay products of both $t$ and $H$, is small but enough to obtain information on the triple Higgs boson self-coupling in a independent way, complementing other studies on the triple vertex.

hep-ph

Emissivity of neutrinos in supernova in a left-right symmetric model

We calculate the emissivity due to neutrino-pair production in $e^+e^-$ annihilation in the context of a left-right symmetric 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 emissivity is dependent of the mixing angle $ϕ$ of the model in the allowed range for this parameter.

hep-ph

Bounding the electromagnetic and weak dipole moments of the tau-lepton in a simplest little Higgs model

From the total cross section for the reaction $e^+e^-\to τ^+τ^-γ$ at the $Z_1$ pole and in the framework of a simplest little Higgs model (SLHM), we get a limit on the characteristic energy scale of the model $f$, $f \geq 5.4$ $TeV$, which in turn induces bounds on the electromagnetic and weak dipole moments of the tau-lepton. Our bounds on the electromagnetic moments are consistent with the bounds obtained by the L3 and OPAL collaborations for the reaction $e^+e^-\to τ^+τ^-γ$. We also obtained bounds on the tau weak dipole moments which are consistent with the bounds obtained recently by the DELPHI and ALEPH collaborations from the reaction $e^+e^-\to τ^+τ^-$.

hep-ph

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 $fb^{-1}$.

hep-ph

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.

hep-ph

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