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1. chinaXiv:201605.01154 [pdf]

Current experimental bounds on stop mass in natural SUSY

Han, Chengcheng; Hikasa, Ken-ichi; Wu, Lei; Yang, Jin Min; Zhang, Yang
Subjects: Physics >> The Physics of Elementary Particles and Fields

Motivated by the recent progress of direct search for the productions of stop pair and sbottom pair at the LHC, we examine the constraints of the search results on the stop ( (t) over tilde (1)) mass in natural SUSY. We first scan the parameter space of natural SUSY in the framework of MSSM, considering the constraints from the Higgs mass, B-physics and electroweak precision measurements. Then in the allowed parameter space we perform a Monte Carlo simulation for stop pair production followed by (t) over tilde (1). t (chi) over tilde (0)(1) or (t) over tilde (1). b (chi) over tilde (+)(1) and sbottom pair production followed by (b) over tilde (1) -> b (chi) over tilde (0)(1) or (b) over tilde (1) -> t (chi) over tilde (-)(1). Using the combined results of ATLAS with 20.1 fb(-1) from the search of l + jets + (sic)(T), hadronic t (t) over bar + (sic)(T) and 2b + (sic)(T), we find that a stop lighter than 600 GeV can be excluded at 95% CL in this scenario.

submitted time 2016-05-09 Hits1861Downloads1053 Comment 0

2. chinaXiv:201605.01149 [pdf]

A light SUSY dark matter after CDMS-II, LUX and LHC Higgs data

Cao, Junjie; Han, Chengcheng; Wu, Lei; Wu, Peiwen; Yang, Jin Min
Subjects: Physics >> The Physics of Elementary Particles and Fields

In SUSY, a light dark matter is usually accompanied by light scalars to achieve the correct relic density, which opens new decay channels of the SM-like Higgs boson. Under current experimental constraints including the latest LHC Higgs data and the dark matter relic density, we examine the status of a light neutralino dark matter in the framework of NMSSM and confront it with the direct detection results of CoGeNT, CDMS-II and LUX. We have the following observations: (i) A dark matter as light as 8 GeV is still allowed and its scattering cross section off the nucleon can be large enough to explain the CoGeNT/CDMS-II favored region; (ii) The LUX data can exclude a sizable part of the allowed parameter space, but still leaves a light dark matter viable; (iii) The SM-like Higgs boson can decay into the light dark matter pair with an invisible branching ratio reaching 30% under the current LHC Higgs data, which may be tested at the 14 TeV LHC experiment.

submitted time 2016-05-09 Hits1408Downloads830 Comment 0

3. chinaXiv:201605.01130 [pdf]

Explaining 750 GeV diphoton excess from top/bottom partner cascade decay in two-Higgs-doublet model extension

Han, Xiao-Fang; Wang, Lei; Wu, Lei; Yang, Jin Min; Zhang, Mengchao
Subjects: Physics >> The Physics of Elementary Particles and Fields

In this paper, we interpret the 750 GeV diphoton excess in the Zee-Babu extension of the two-Higgs-doublet model by introducing a top partner (T)/bottom partner (B). In the alignment limit, the 750 GeV resonance is identified as the heavy CP-even Higgs boson (H), which can be sizably produced via the QCD process pp -> T (T) over bar or pp -> B (B) over bar followed by the decay T -> Ht or B -> Hb. The diphoton decay rate of His greatly enhanced by the charged singlet scalars predicted in the Zee-Babu extension and the total width of H can be as large as 7 GeV. Under the current LHC constraints, we scan the parameter space and find that such an extension can account for the observed diphoton excess. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.

submitted time 2016-05-09 Hits1543Downloads859 Comment 0

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