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M. A. Pérez

Publications and source records attributed to M. A. Pérez.

8 recordsLinked to original sources

Corrigendum to "$m$-Periodic Gorenstein objects" [J. Algebra 621 (2023)]

Let $(\mathcal{A,B})$ be a GP-admissible pair and $(\mathcal{Z,W})$ be a GI-admissible pair of classes of objects in an abelian category $\mathcal{C}$, and consider the class $π\mathcal{GP}_{(ω,\mathcal{B},1)}$ of $1$-periodic $(ω,\mathcal{B})$-Gorenstein projective objects, where $ω:= \mathcal{A} \cap \mathcal{B}$ and $ν:= \mathcal{Z} \cap \mathcal{W}$. We claimed in \cite[Lem. 8.1]{HMP2023m} that the $(\mathcal{Z,W})$-Gorenstein injective dimension of $π\mathcal{GP}_{(ω,\mathcal{B},1)}$ is bounded by the $(\mathcal{Z,W})$-Gorenstein injective dimension of $ω$, provided that: (1) $ω$ is closed under direct summands, (2) $\mathrm{Ext}^1(π\mathcal{GP}_{(ω,\mathcal{B},1)},ν) = 0$, and (3) every object in $π\mathcal{GP}_{(ω,\mathcal{B},1)}$ admits a $\mathrm{Hom}(-,ν)$-acyclic $ν$-coresolution. These conditions are their duals are part of what we called ``Setup 1''. Moreover, if we replace $π\mathcal{GP}_{(ω,\mathcal{B},1)}$ by the class $\mathcal{GP}_{(\mathcal{A,B})}$ of $(\mathcal{A,B})$-Gorenstein projective objects, the resulting inequality is claimed to be true under a set of conditions named ``Setup 2''. The proof we gave for the claims $\mathrm{Gid}_{(\mathcal{Z,W})}(π\mathcal{GP}_{(ω,\mathcal{B},1)}) \leq \mathrm{Gid}_{(\mathcal{Z,W})}(ω)$ and $\mathrm{Gid}_{(\mathcal{Z,W})}(\mathcal{GP}_{(\mathcal{A,B})}) \leq \mathrm{Gid}_{(\mathcal{Z,W})}(ω)$ is incorrect, and the purpose of this note is to exhibit a corrected proof of the first inequality, under the additional assumption that every object in $π\mathcal{GP}_{(ω,\mathcal{B},1)}$ has finite injective dimension relative to $\mathcal{Z}$. Setup 2 is no longer required, and as a result the second inequality was removed. We also fix those results in §\ 8 of \cite{HMP2023m} affected by Lemma 8.1, and comment some applications and examples.

math.RT↗

Lepton flavor changing Higgs Boson decays in a Two Higgs Doublet Model with a fourth generation of fermions

We analyze the flavor changing decay $h\rightarrow μτ$ in the framework of a Two Higgs Doublet Model with a fourth generation of fermions (4G2HDM) which couples only to the heavy scalar doublet. We obtain that the respective branching ratio at one-loop level can reach values as high as $ 10^{-4}-10^{-6} $ for masses of $ 300 $ GeV to $ 1 $ TeV for the heavy leptons in the fourth family and the new heavy Higgs bosons. These radiative corrections are of the same order of magnitude as the tree level prediction of the 4G2HDM.

hep-ph↗

New physics effects in the Higgs trilinear self-coupling through one-loop radiative corrections

We compute the one-loop corrections to the triple Higgs self-interaction $hhh$ in the framework of the Standard Model (SM), the Two Higgs Doublet Model type III (THDM-III) and the Littlest Higgs Model with T parity (LHBM+T). Our results are compared with previous results for the SM. In particular, we find that an imaginary part for the $λ_{hhh}$ form factor is induced when one of the Higgs boson legs is off-mass shell with 4-momentum magnitude higher than the Higgs boson mass. This contribution is sensitive to virtual effects of the Higgs self-interaction, that induces a radiative correction to the $hhh$ coupling of order 11%. However, the radiative corrections associated to the new degrees of freedom of the THDM-III and the LHBM+T are rather smaller and comparable to the $W^\pm$ and $Z^0$ gauge bosons one-loop corrections.

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↗

The γγ\to ϕ_iϕ_j processes in the type-III two-Higgs-doublet model

We discuss the implications of assuming a four-zero Yukawa texture and a general Higgs potential for the production of neutral Higgs boson pairs at γγcolliders through the γγ\to ϕ_iϕ_j (ϕ_i = h, H, A) reaction within the context of the two Higgs doublet model type III. Exact analytical expressions for the γγ\to ϕ_iϕ_j reaction are presented. The use of a nonlinear R_ξ-gauge, which considerably simplifies the loop calculations and renders compact analytical expressions, is stressed. We show that these processes are very sensitive to a general structure of the Higgs potential that impact the triple and quartic couplings of the scalar sector. We present results for scenarios of the parameters of the model that are still consistent with current experimental constraints. It is found that the cross sections for the γγ\to ϕ_iϕ_j processes can be up to two orders of magnitude larger than those gotten in 2HDM type I and type II. The possibility of a light CP--scalar is also studied.

hep-ph↗

Constraints on unparticle physics from the $gt\bar t$ anomalous coupling

We study the impact of unparticle physics to the chromomagnetic dipole moment (CMDM) of the top quark. We compute the effect induced by unparticle operators of scalar and vector nature coupled to fermions on the CMDM. We find that this dipole moment is sensitive to the scale dimensions $d_u$ of the unparticle and the new couplings of the respective effective operators. Using the bounds imposed on the CMDM by low-energy precision and Tevatron measurements we derive indirect limits on the unparticle parameter space. In particular, we find that the scalar-unparticle operator contribution fulfills both constraints for most of the unparticle parameter space, while the low-energy precision bound on the CMDM excludes a vector-unparticle contribution for low values of respective scale dimension $d_u$.

hep-ph↗

Chromomagnetic Dipole Moment of the Top Quark Revisited

We study the complete one-loop contributions to the chromagnetic dipole moment $Δκ$ of the top quark in the Standard Model, two Higgs doublet models, topcolor assited technicolor models (TC2), 331 models and extended models with a single extra dimension. We find that the SM predicts $Δκ= - 0.056$ and that the predictions of the other models are also consitent with the constraints imposed on $Δκ$ by low-energy precision measurements.

hep-ph↗

New Physics Effects on Higgs Production at $γγ$ Colliders

We study heavy physics effects on the Higgs production in $γγ$ fusion using the effective Lagrangian approach. We find that the effects coming from new physics may enhance the standard model predictions for the number of events expected in the final states $\bar bb$, $WW$, and $ZZ$ up to one order of magnitude, whereas the corresponding number of events for the final state $\bar tt$ may be enhanced up to two orders of magnitude.

hep-ph↗