arXiv subjects

Jesus M. Mira

Publications and source records attributed to Jesus M. Mira.

4 recordsLinked to original sources

arXiv2005

Hierarchical radiative masses in a supersymmetric three-family model without Higgsinos

We study the scalar potential and the mass spectrum of the supersymmetric extension of a three-family model based on the local gauge group $SU(3)_C\otimes SU(3)_L\otimes U(1)_X$, with anomalies canceled among the three families in a nontrivial fashion. In this model the slepton multiplets play the role of the Higgs scalars and no Higgsinos are needed, with the consequence that the sneutrino, the selectron and six other sleptons play the role of the Goldstone bosons of the theory. By introducing an Abelian anomaly-free discrete symmetry and aligning the vacuum in a convenient way, we get a consistent mass spectrum for the scalars and for the spin 1/2 quarks and charged leptons, where only the top and charm quarks and the tau lepton acquire tree level masses while the remaining ordinary charged fermions acquire radiative hierarchical masses.

hep-ph↗

arXiv2003

Supersymmetric One-family Model without Higgsinos

The Higgs potential and the mass spectrum of the N=1 supersymmetric extension of a recently proposed one-family model based on the local gauge group $SU(3)_c \otimes SU(3)_L \otimes U(1)_X$, which is a subgroup of the electroweak-strong unification group $E_6$, is analyzed. In this model the slepton multiplets play the role of the Higgs scalars and no Higgsinos are needed, with the consequence that the sneutrino, the selectron and six other sleptons play the role of the Goldstone bosons. We show how the $μ$ problem is successfully addressed in the context of this model which also predicts the existence of a light CP-odd scalar.

hep-ph↗

arXiv2000

Non anomalous U(1)_H gauge model of flavor

A non anomalous horizontal $U(1)_H$ gauge symmetry can be responsible for the fermion mass hierarchies of the minimal supersymmetric standard model. Imposing the consistency conditions for the absence of gauge anomalies yields the following results: i) unification of leptons and down-type quarks Yukawa couplings is allowed at most for two generations. ii) The $μ$ term is necessarily somewhat below the supersymmetry breaking scale. iii) The determinant of the quark mass matrix vanishes, and there is no strong $CP$ problem. iv) The superpotential has accidental $B$ and $L$ symmetries. The prediction $m_{\rm up}=0$ allows for an unambiguous test of the model at low energy.

hep-ph↗

arXiv1998

$B\toτμ(X)$ decays in SUSY models without R-parity

Being strictly forbidden in the standard model, experimental detection of the lepton flavor violating decays $B(\bar B)\toτ^+μ^-$ and $b(\bar b)\to Xτ^+μ^-$ would constitute an unmistakable indication of new physics. We study these decays in supersymmetric models without R-parity and without lepton number. In order to derive order of magnitude predictions for the branching ratios, we assume a horizontal U(1) symmetry with horizontal charges chosen to explain the magnitude of fermion masses and quark mixing angles. We find that the branching ratios for decays with a $τμ$ pair in the final state are not particularly suppressed with respect to the lepton flavor conserving channels. In general in these models ${\rm B}[b\toμ^+μ^-(X)]\lsim {\rm B}[b(\bar b)\toτ^+μ^-(X)] \lsim {\rm B}[b\toτ^+τ^-(X)]$. While in some cases the rates for final states $τ^+τ^-$ can be up to one order of magnitude larger than the lepton flavor violating channel, due to better efficiencies for muon detection and to the absence of standard model contributions, decays into $τμ$ final states appear to be better suited to reveal this kind of new physics.

hep-ph↗