arXiv subjects

JeongHyeon Song

Publications and source records attributed to JeongHyeon Song.

4 recordsLinked to original sources

arXiv2001

Probing large extra dimensions with spin configuration of top quark pair production at the JLC

We explore signatures of large extra dimensions with a polarized electron/positrn beam at the Joint Linear Collider (JLC). We point out that spin informations can be useful to study indirect signals for large extra dimensions due to spin-2 nature of Kaluza-Klein gravitons. The spin configurations of the top quark pair production at $e^+ e^-$ and $γγ$ collisions provide an unique testing ground to search for effects of the large extra dimensions. Especially we show the forward-backward asymmetry is a good probe at $e^+ e^- \to t \bar{t}$ process and we can define a new asymmetry observable effective for $γγ\to t \bar{t}$ process.

hep-ph↗

arXiv1999

Polarization Effects on the $e+e- \to W^+W^-$ process with Large Extra Dimensions

We study large extra dimension effects on the polarizations of the $W$ pair and electron beam at the $e^+ e^-\to W^+ W^-$ process. It is shown that the measurements of the cross section for transversely polarized $W$ pair with the right-handed electron beam remarkably enhance the possibilities to see the low scale quantum gravity effects. Higher Linear Collider bounds on the string scale in this model can be obtained by using the left-handed electron beam.

hep-ph↗

arXiv1999

Large Extra Dimension Effects on the Spin Configuration of the Top Quark Pair at e^+ e^- Colliders

Large extra dimension effects on the spin configuration of the top quark pair at the $e^+ e^-\to t\bar{t}$ process are studied. It is shown that the TeV scale quantum gravity effects cause significant deviations from the Standard Model predictions for the spin configuration in the off-diagonal basis: they lead to substantial cross sections of the like-spin states of the top quark pair, which vanish in the SM; they weaken the pure dominance of the processes, the Up-Down (Down-Up) spin states for the left-handed (right-handed) beam. In addition it is shown that the angular cut $-0.5<\cosθ<0$ is very effective to determine the sign of the quantum gravity corrections.

hep-ph↗

arXiv1995

A Proposed Scale-Dependent Cosmology for the Inhomogeneous Cosmology

We propose a scale-dependent cosmology in which the Robertson--Walker metric and the Einstein equation are modified in such a way that $Ω_0$, $H_0$ and the age of the Universe all become scale-dependent. Its implications on the observational cosmology and possible modifications of the standard Friedmann cosmology are discussed. For example, the age of the Universe in this model is longer than that of the standard model.

hep-ph↗