arXiv subjects

Jeonghyeon Song

Publications and source records attributed to Jeonghyeon Song.

76 records · Page 5Linked to original sources

arXiv2001

Enhancement of the Higgs pair production at LHC; the MSSM and extra dimension effects

The neutral Higgs pair production at the LHC is studied in the MSSM, the large extra dimensional (ADD) model and the Randall-Sundrum (RS) model, where the total cross section can be significantly enhanced compared to that in the SM. The $p_{_T}$, invariant mass and rapidity distributions of each model have been shown to be distinctive: The ADD model raises the $p_T$ and invariant mass distributions at high scales of $p_T$ and invariant mass; in the RS model resonant peaks appear after the SM contribution dies away; the SM and the MSSM distributions drop rapidly at those high scales; in the ADD and the RS models the rapidity distributions congregate more around the center. It is concluded that various distributions of the Higgs pair production at the LHC with restrictive kinematic cuts would provide one of the most robust signals for the extra dimensional effects.

hep-ph↗

arXiv2001

Radion effects on the production of an intermediate-mass scalar and Z at LEP II

We have studied the $e^+ e^- \to Z ϕ_i \to Z jj$ process, where $ϕ_i$ is the Higgs and/or radion bosons. The implications of the radion effects on the preliminary ALEPH data are also discussed. The case of the lighter radion than Higgs boson is disfavored by the ALEPH analyses of the $b$ tagged four-jet data, since the radion predominantly decays into two gluon jets due to the QCD trace anomaly. If the radion is highly degenerate in mass with the Higgs, the cross section can be increased more than at one sigma level, with natural scale of the vacuum expectation value of the radion.

hep-ph↗

arXiv2001

Scenario of Light Sterile Neutrinos with A Heavy Tau Neutrino in A Supersymmetric Model

Three light sterile neutrinos (ν_e^s, ν_μ^s and ν_τ^s) are introduced to accommodate all the available neutrino data: the atmospheric neutrino anomaly is explained by ν_μ-ν_μ^s oscillation with maximal mixing; the solar one is due to ν_e-ν_e^s oscillation of small angle Mikheyev-Smirnov-Wolfenstein type; the Liquid Scintillation Neutrino Detector data is from ν_e -ν_μoscillations, so that the neutrinos can be the hot component of the dark matter. The big bang nucleosynthesis constraint is satisfied by taking the tau neutrino to be 10 MeV heavy. The ν_τdecay is discussed in a model of gauge mediated supersymmetry breaking. The decay mode ν_τ\to\tilde{G}γwith \tilde{G} being the gravitino is proposed. The ν_τhas a rather long lifetime \sim 10^3-10^{13} sec. Its implication to the Gamma-ray Burst is discussed.

hep-ph↗

arXiv1999

Four Light Neutrinos in Singular Seesaw Mechanism with Abelian Flavor Symmetry

The four light neutrino scenario, which explains the atmosphere, solar and LSND neutrino experiments, is studied in the framework of the seesaw mechanism. By taking both the Dirac and Majorana mass matrix of neutrinos to be singular, the four neutrino mass spectrum consisting of two almost degenerate pairs separated by a mass gap $\sim 1$ eV is naturally generated. Moreover the right-handed neutrino Majorana mass can be at $\sim 10^{14}$ GeV scale unlike in the usual singular seesaw mechanism. Abelian flavor symmetry is used to produce the required neutrino mass pattern. A specific example of the flavor charge assignment is provided to show that maximal mixings between the $ν_μ-ν_τ$ and $ν_e-ν_s$ are respectively attributed to the atmosphere and solar neutrino anomalies while small mixing between two pairs to the LSND results. The implication in the other fermion masses is also discussed.

hep-ph↗