arXiv subjects

Fuqiang Xu

Publications and source records attributed to Fuqiang Xu.

4 recordsLinked to original sources

arXiv2010

Higgs boson production in photon-photon collision at ILC: a comparative study in different little Higgs models

We study the process γγ->h->bb_bar at ILC as a probe of different little Higgs models, including the simplest little Higgs model (SLH), the littlest Higgs model (LH), and two types of littlest Higgs models with T-parity (LHT-I, LHT-II). Compared with the Standard Model (SM) prediction, the production rate is found to be sizably altered in these little Higgs models and, more interestingly, different models give different predictions. We find that the production rate can be possibly enhanced only in the LHT-II for some part of the parameter space, while in all other cases the rate is suppressed. The suppression can be 10% in the LH and as much as 60% in both the SLH and the LHT-I/LHT-II. The severe suppression in the SLH happens for a large \tanβand a small m_h, in which the new decay mode h->ηη(ηis a light pseudo-scalar) is dominant; while for the LHT-I/LHT-II the large suppression occurs when f and m_h are both small so that the new decay mode h->A_H A_H is dominant. Therefore, the precision measurement of such a production process at the ILC will allow for a test of these models and even distinguish between different scenarios.

hep-ph↗

arXiv2009

An Extension for Direct Gauge Mediation of Metastable Supersymmetry Breaking

We study the direct mediation of metastable supersymmetry breaking by a Φ^2-deformation to the ISS model and extend it by splitting both TrΦand TrΦ^2 terms in the superpotential and gauging the flavor symmetry. We find that with such an extension the enough long-lived metastable vacua can be obtained and the proper gaugino masses can be generated. Also, this allows for constructing a kind of models which can avoid the Landau pole problem. Especially, in our metastable vacua there exist a large region for the parameter m_3 which can satisfy the phenomenology requirements and allow for a low SUSY breaking scale (\sim 100 TeV).

hep-ph↗

arXiv2007

Virtual Effects of Split SUSY in Higgs Productions at Linear Colliders

In split supersymmetry the gauginos and higgsinos are the only supersymmetric particles possibly accessible at foreseeable colliders like the CERN Large Hadron Collider (LHC) and the International Linear Collider (ILC). In order to account for the cosmic dark matter measured by WMAP, these gauginos and higgsinos are stringently constrained and could be explored at the colliders through their direct productions and/or virtual effects in some processes. The clean environment and high luminosity of the ILC render the virtual effects of percent level meaningful in unraveling the new physics effects. In this work we assume split supersymmetry and calculate the virtual effects of the WMAP-allowed gauginos and higgsinos in Higgs productions e+e- -> Z h and e+e- -> ν_e \bar_ν_e h through WW fusion at the ILC. We find that the production cross section of e+e- -> Zh can be altered by a few percent in some part of the WMAP-allowed parameter space, while the correction to the WW-fusion process e+e- -> ν_e \bar_ν_e h is below 1%. Such virtual effects are correlated with the cross sections of chargino pair productions and can offer complementary information in probing split supersymmetry at the colliders.

hep-ph↗

arXiv2006

Constraints on Hybrid Inflation from Flat Directions in Supersymmetry

We examine the constraints on F-term hybrid inflation by considering the flat directions in the Minimal Supersymmetric Standard Model (MSSM). We find that some coupling terms between the flat direction fields and the field which dominates the energy density during inflation are quite dangerous and can cause the no-exit of hybrid inflation even if their coupling strength is suppressed by Planck scale. Such couplings must be forbidden by imposing some symmetry for a successful F-term hybrid inflation. At the same time, we find that in the D-term inflation these couplings can be avoided naturally. Further, given the tachyonic preheating, we discuss the feasibility of Affleck-Dine baryogenesis after the F-term and D-term inflations.

hep-ph↗