Publications (146)383.9 Total impact
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ABSTRACT: We perform a detailed semianalytical analysis of the electroweak phase transition (EWPT) property in NMSSM, which serves as a good benchmark model in which the 126 GeV Higgs mixes with a singlet. In this case, a strongly first order electroweak phase transition (SFOEWPT) is achieved by the treelevel effects and the phase transition strength $\gamma_c$ is determined by the vacua energy gap at $T=0$. We make an anatomy of the energy gap at both treelevel and looplevel and extract out a dimensionless phase transition parameter $R_\kappa \equiv 4 \kappa v_s / A_\kappa$, which can replace $A_\kappa$ in the parameterization and affect the light CP odd and even Higgs spectra. We find that SFOEWPT only occurs in $R_\kappa \sim 1$ and positive $R_\kappa \lesssim \mathcal{O}(10)$, which in the nonPQ limit case would prefer either a relatively light CP odd or CP even Higgs boson $\sim (60, 100)$ GeV, therefore serves as a smoking gun signal and requires new search strategies at the LHC.05/2014;  [Show abstract] [Hide abstract]
ABSTRACT: In this work we show that the general singlet extension of the MSSM can naturally provide a selfinteracting singlino dark matter to solve the small cosmological scale anomalies (a large Sommerfeld enhancement factor can also be obtained). However, we find that the NMSSM (the singlet extension of the MSSM with Z3 symmetry) cannot achieve this due to the restricted parameter space. In our analysis we introduce the concept of symmetric and antisymmetric viscosity cross sections to deal with the nonrelativistic Majoranafermion dark matter scattering.04/2014;  [Show abstract] [Hide abstract]
ABSTRACT: In light of the Higgs discovery and the nonobservation of sparticles at the LHC, we revisit the SUSY induced top quark flavor changing decay into the Higgs boson. We perform a scan over the relevant parameter space of the MSSM by considering the constraints from the Higgs mass measurement, the LHC search for SUSY, the vacuum stability, the precision electroweak observables as well as $B \to X_s \gamma$. We obtain the following observations: (1) In the MSSM, the branching ratio of $ t \to c h$ can only reach $10^{6}$, which is about one order smaller than the old results before the LHC data. Among the considered constraints, the Higgs mass and the LHC sparticle search results are found to play an important role in limiting the prediction. (2) In the singlet extension of the MSSM, since the squark sector is less constrained by the Higgs mass, $Br(t \to c h)$ can reach $O(10^{5})$ in the allowed parameter space. (3) The chiralconserving mixings $\delta_{LL}$ and $\delta_{RR}$ have nondecoupling effects on $t \to c h$. Unlike the SUSYQCD correction to the $h\bar{b} b$ vertex, such nondecoupling effects are not sensitive to $\tan \beta$ and the CPodd Higgs boson mass $m_A$. For rather heavy squarks and gluino above $2 TeV$, $Br(t\to c h)$ can still reach $O(10^{7})$ under the constraints.04/2014;  [Show abstract] [Hide abstract]
ABSTRACT: The multisector SUSY breaking predicts the existence of goldstini, which could couple more strongly to visible fields than ordinary gravitino. Then the lightest neutralino and chargino can decay into a goldstini plus a Zboson, Higgs boson or Wboson. In this note we perform a Monte Carlo simulation for the direct productions of the lightest neutralino and chargino followed by the decays to goldstini. Considering scenarios with higgsinolike, binolike or winolike lightest neutralino, we find that the signaltobackground ratio at the high luminosity LHC is between 6 and 25% and the statistical significance can be above 5sigma.03/2014;  [Show abstract] [Hide abstract]
ABSTRACT: Motivated by the future precision test of the Higgs boson at an $e^+e^$ Higgs factory, we calculate the production $e^+e^ \to ZH\gamma$ in the Standard Model with complete nexttoleading order electroweak corrections. We find that for $\sqrt{s}=240$ (350) GeV the cross section of this production is sizably reduced by the electroweak corrections, which is $1.03$ (5.32) fb at leading order and 0.72 (4.79) fb at nexttoleading order. The transverse momentum distribution of the photon in the final states is also presented.11/2013;  [Show abstract] [Hide abstract]
ABSTRACT: 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, CDMSII 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/CDMSII 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 SMlike Higgs boson can decay into the light dark matter pair with an invisible branching ratio reaching 30% under the current LHC Higgs data, which can be tested at the 14 TeV LHC experiment.11/2013;  [Show abstract] [Hide abstract]
ABSTRACT: We propose a new strategy to search for light, nearly degenerate higgsinos within the natural MSSM at LHC. We demonstrate that the entire higgsino mass range $\mu$ in 100200 GeV, which is preferred by the naturalness, can be probed at $5\sigma$ significance through the monojet search at 14 TeV HLLHC with 1500 fb$^{1}$ luminosity. The proposed method can also probe certain region in the parameter space for the lightest neutralino with a high higgsino purity, that cannot be reached by planned direct detection experiments at XENON1T(2017).10/2013;  [Show abstract] [Hide abstract]
ABSTRACT: We calculate the twoloop beta functions for three gauge couplings in split supersymmetry (splitSUSY) which assumes a very high scalar mass scale $M_S$. We find that in splitSUSY with a large $M_S$ the gauge coupling unification requires a lower bound on gaugino mass. Combined with the constraints from the dark matter relic density and direct detection limits, we find that splitSUSY is very restricted and the allowed parameter can be fully covered by XENON1T(2017). So the splitSUSY scenario with dark matter and gauge coupling unification requirements will be either discovered or excluded at XENON1T(2017).10/2013;  [Show abstract] [Hide abstract]
ABSTRACT: In the NexttoMinimal Supersymemtric Standard Model (NMSSM), one of the neutral Higgs scalars (CPeven or CPodd) may be lighter than half of the SMlike Higgs boson. In this case, the SMlike Higgs boson h can decay into such a light scalar pair and consequently the diphoton and ZZ signal rates at the LHC will be suppressed. In this work, we examine the constraints of the latest LHC Higgs data on such a possibility. We perform a comprehensive scan over the parameter space of the NMSSM by considering various experimental constraints and find that the LHC Higgs data can readily constrain the parameter space and the properties of the light scalar, e.g., at 3 sigma level this light scalar should be highly singlet dominant and the branching ratio of the SMlike Higgs boson decay into the scalar pair should be less than 30%. Also we investigate the detection of this scalar at various colliders. Through a detailed Monte Carlo simulation we find that under the constraints of the current Higgs data this light scalar can be accessible at the LHC14 with an integrated luminosity over 300 fb^{1}.09/2013;  [Show abstract] [Hide abstract]
ABSTRACT: 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 ($\tilde{t}_1$) 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, Bphysics and electroweak precision measurements. Then in the allowed parameter space we perform a Monte Carlo simulation for stop pair production followed by $\tilde{t}_{1} \to t \tilde{\chi}_{1}^{0}$ or $\tilde{t}_{1} \to b \tilde{\chi}_{1}^{+}$ and sbottom pair production followed by $\tilde{b}_{1} \to b \tilde{\chi}_{1}^{0}$ or $\tilde{b}_{1} \to t \tilde{\chi}_{1}^{}$. Using the combined results of ATLAS with 20.1 fb$^{1}$ from the search of $\ell+{\rm jets}+\slashed E_{T}$, hadronic $t\bar{t}+\slashed E_{T}$ and $2b+\slashed E_{T}$, we find that a stop lighter than 600 GeV can be excluded at 95% CL in this scenario.08/2013; 
Article: Dark matter in little Higgs model under current experimental constraints from LHC, Planck and Xenon
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ABSTRACT: We examine the status of dark matter (heavy photon) in the littlest Higgs model with Tparity (LHT) in light of the new results from the LHC Higgs search, the Planck dark matter relic density and the XENON100 limit on the dark matter scattering off the nucleon. We obtain the following observations: (i) For the LHC Higgs data, the LHT can well be consistent with the CMS results but disfavored by the ATLAS observation of diphoton enhancement; (ii) For the dark matter relic density, the heavy photon in the LHT can account for the Planck data for the small mass splitting of mirror lepton and heavy photon; (iii) For the dark matter scattering off the nucleon, the heavy photon can give a spinindependent cross section below the XENON100 upper limit for $m_{A_H}>95$ GeV ($f> 665$ GeV); (iv) A fit using the CMS Higgs data gives the lowest chisquare of 2.63 (the SM value is 4.75) at $f\simeq$ 1120 GeV and $m_{A_H}\simeq$ 170 GeV (at this point the dark matter constraints from Planck and XENON100 can also be satisfied). Such a best point and its nearby favored region (even for a $f$ value up to 3.8 TeV) can be covered by the future XENON1T (2017) experiment.Physical Review D 07/2013; 88(7). · 4.69 Impact Factor 
Article: Higgs pair production with SUSY QCD correction: revisited under current experimental constraints
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ABSTRACT: We consider the current experimental constraints on the parameter space of the MSSM and NMSSM. Then in the allowed parameter space we examine the Higgs pair production at the 14 TeV LHC via $b\bar{b}\to hh$ ($h$ is the 125 GeV SMlike Higg boson) with oneloop SUSY QCD correction and compare it with the production via $gg\to hh$. We obtain the following observations: (i) For the MSSM the production rate of $b\bar{b} \to hh$ can reach 50 fb and thus can be competitive with $gg \to hh$, while for the NMSSM $b\bar{b} \to hh$ has a much smaller rate than $gg \to hh$ due to the suppression of the $hb\bar{b}$ coupling by the singlet component of $h$; (ii) The SUSYQCD correction to $b\bar{b} \to hh$ is sizable, which can reach 30% for the MSSM and 10% for the NMSSM within the $1\sigma$ region of the Higgs data; (iii) In the heavy SUSY limit (all soft mass parameters become heavy), the SUSY effects decouple rather slowly from the Higgs pair production (especially the $gg\to hh$ process), which, for $M_{\rm SUSY}=5$ TeV and $m_A<1$ TeV, can enhance the production rate by a factor of 1.5 and 1.3 for the MSSM and NMSSM, respectively. So, the Higgs pair production at the LHC may be used to unravel the effects of heavy sparticles in case of nonobservation from direct search.07/2013; 
Article: Natural SUSY from SU(5) Orbifold GUT
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ABSTRACT: We propose a realistic 5D orbifold GUT model that can reduce to natural (or radiative natural) supersymmetry as the low energy effective theory. Supersymmetry as well as gauge symmetry are broken by the twist boundary conditions. We find that it is nontrivial to introduce other flavor symmetry other than the $SU(2)_R$ Rsymmetry. We ameliorate the tension between the small number of free parameters and the successful electroweak symmetry breaking by introducing nonminimal Kahler potentials. A large trilinear term $A_t$, which is necessary to give a 125 GeV Higgs boson, is naturally predicted in our scenario. A scan under current experimental constraints shows that our model can indeed realize natural (or radiative natural) supersymmetry.04/2013;  [Show abstract] [Hide abstract]
ABSTRACT: In order to have massive neutrinos, the righthanded neutrino/sneutrino superfield ($N$) need to be introduced in supersymmetry. In the framework of NMSSM (the MSSM with a singlet $S$) such an extension will dynamically lead to a TeVscale Majorana mass for the righthanded neutrino through the $SNN$ coupling when $S$ develops a vev (the free Majorana mass term is forbidden by the assumed $Z_3$ symmetry). Also, through the couplings $SNN$ and $SH_uH_d$, the SMlike Higgs boson (a mixture of $H_u$, $H_d$ and $S$) can naturally couple with the righthanded neutrino/sneutrino. As a result, the TeVscale righthanded neutrino/sneutrino may significantly contribute to the Higgs boson mass. Through an explicit calculation, we find that the Higgs boson mass can indeed be sizably altered by the righthanded neutrino/sneutrino. Such new contribution can help to push up the SMlike Higgs boson mass and thus make the NMSSM more natural.Journal of High Energy Physics 03/2013; 2013(7). · 5.62 Impact Factor 
Article: The SM extension with coloroctet scalars: diphoton enhancement and global fit of LHC Higgs data
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ABSTRACT: In light of the significant progress of the LHC to determine the properties of the Higgs boson, we investigate the capability of the ManoharWise model in explaining the Higgs data. This model extends the SM by one family of coloroctet and isospindoublet scalars, and it can sizably alter the coupling strengths of the Higgs boson with gluons and photons. We first examine the current constraints on the model, which are from unitarity, the LHC searches for the scalars and the electroweak precision data (EWPD).In implementing the unitarity constraint, we use the properties of the SU(3) group to simplify the calculation. Then in the allowed parameter space we perform a fit of the model, using the latest ATLAS and CMS data, respectively. We find that the ManoharWise model is able to explain the data with \chi^2 significantly smaller than the SM value. We also find that the current Higgs data, especially the ATLAS data, are very powerful in further constraining the parameter space of the model. In particular, in order to explain the diphoton enhancement reported by the ATLAS collaboration, the sign of the hgg coupling is usually opposite to that in the SM.Journal of High Energy Physics 03/2013; 2013(8). · 5.62 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: In light of the recent LHC Higgs search data, we investigate the pair production of a SMlike Higgs boson around 125 GeV in the MSSM and NMSSM. We first scan the parameter space of each model by considering various experimental constraints, and then calculate the Higgs pair production rate in the allowed parameter space. We find that in most cases the dominant contribution to the Higgs pair production comes from the gluon fusion process and the production rate can be greatly enhanced, maximally 10 times larger than the SM prediction (even for a TeVscale stop the production rate can still be enhanced by a factor of 1.3). We also calculate the chisquare value with the current Higgs data and find that in the most favored parameter region the production rate is enhanced by a factor of 1.45 in the MSSM, while in the NMSSM the production rate can be enhanced or suppressed (\sigma_{SUSY}/\sigma_{SM} varies from 0.7 to 2.4).Journal of High Energy Physics 01/2013; 2013(4). · 5.62 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: If supersymmetry is broken independently in multiple sectors with different scales, a number of goldstinos will be generated. One linear combination of these goldstinos is massless and eaten by the gravitino, while the orthogonal combinations acquire a tree level mass and become the physical states named goldstini (G'). Compared to the gravitino, such goldstini could couple more strongly to the visible fields and lead to some exotic phenomenology. In this note we first check the goldstini couplings in some GMSB models and find that the goldstiniphotonneutralino interaction may be very small while the goldstiniZneutralino and goldstiniHiggsneutralino interactions may be sizable. This can induce a new decay mode for the Higgs boson: h> G'+\chi > Z+2G'. Then in an effective model with conservative fixed parameters we study the observability of this decay channel at the LHC and find that it is not accessible at the finished 8 TeV run (25 /fb) or 14 TeV run with 100 /fb, but might be observed at the high luminosity LHC (14 TeV, 10003000 /fb) if the systematics of the backgrounds can be well understood.Physics Letters B 01/2013; 726(1). · 4.57 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: In light of recent remarkable progress in Higgs search at the LHC, we study the rare decay process $h \to Z\gamma$ and show its correlation with the decay $h \to \gamma\gamma$ in low energy SUSY models such as CMSSM, MSSM, NMSSM and nMSSM. Under various experimental constraints, we scan the parameter space of each model, and present in the allowed parameter space the SUSY predictions on the $Z\gamma$ and $\gamma\gamma$ signal rates in the Higgs production at the LHC and future e+e linear colliders. We have following observations: (i) Compared with the SM prediction, the $Z\gamma$ and $\gamma\gamma$ signal rates in the CMSSM are both slightly suppressed; (ii) In the MSSM, both the $Z\gamma$ and $\gamma\gamma$ rates can be either enhanced or suppressed, and in optimal case, the enhancement factors can reach 1.2 and 2 respectively; (iii) In the NMSSM, the $Z\gamma$ and $\gamma\gamma$ signal rates normalized by their SM predictions are strongly correlated, and vary from 0.2 to 2; (iv) In the nMSSM, the $Z\gamma$ and $\gamma\gamma$ rates are greatly reduced. Since the correlation behavior between the Z\gamma signal and the \gamma\gamma signal is so modeldependent, it may be used to distinguish the models in future experiments.Journal of High Energy Physics 01/2013; · 5.62 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: We confront the little Higgs theory with the LHC Higgs search data (up to 17 fb$^{1}$ of the combined 7 and 8 TeV run). Considering some typical models, namely the littlest Higgs model (LH), the littlest Higgs model with Tparity (LHTA and LHTB) and the simplest little Higgs model (SLH), we scan over the parameter space in the region allowed by current experiments. We find that in these models the inclusive and exclusive (via gluongluon fusion) diphoton and $ZZ^*$ signal rates of the Higgs boson are always suppressed and approach to the SM predictions for a large scale $f$. Thus, the $ZZ^*$ signal rate is within the $1\sigma$ range of the experimental data while the inclusive diphoton signal rate is always outside the $2\sigma$ range. Especially, in the LHTA the diphoton signal rate is outside the $3\sigma$ range of the experimental data for $f < 800$ GeV. We also perform a global $\chi^2$ fit to the available LHC and Tevatron Higgs data, and find that these models provide no better global fit to the whole data set (only for some special channels a better fit can be obtained, specially in the LHTB).Physical review D: Particles and fields 01/2013; 87(5).  [Show abstract] [Hide abstract]
ABSTRACT: The excess of top quark forwardbackward asymmetry ($A^t_{FB}$) reported by the Tevatron and the enhancement of the Higgs decay to diphoton observed by the LHC may point to a same origin of new physics. In this note we examined such anomalies in the twoHiggsdoublet model with a colortriplet scalar. We found that under current experimental constraints this model can simultaneously explain both anomalies at $1\sigma$ level. Also, we examined the Higgs decay $h\to Z\gamma$ and displayed its correlation with $h\to \gamma\gamma$. We found that unlike other models, this model predicts a special correlation between $h\to Z\gamma$ and $h\to \gamma\gamma$, i.e., the $Z\gamma$ rate is highly suppressed while the $\gamma\gamma$ rate is enhanced. This behavior may help to distinguish this model in the future high luminosity run of the LHC.European Physical Journal C 12/2012; · 5.25 Impact Factor
Publication Stats
2k  Citations  
383.90  Total Impact Points  
Top Journals
Institutions

1997–2013

Academia Sinica
Tâ€™aipei, Taipei, Taiwan


2009–2012

Chinese Academy of Sciences
 Institute of Theoretical Physics
Peping, Beijing, China 
Northeast Institute of Geography and Agroecology
 Institute of Theoretical Physics
Peping, Beijing, China


2002–2010

Yantai University
 Department of Physics
Beijing, Beijing Shi, China


2008–2009

Institute of physics china
Peping, Beijing, China


1992–2007

Henan Normal University
Henanâ€™an, Guangdong, China


2003

Hiroshima University
 Graduate School of Science
Hiroshimashi, Hiroshimaken, Japan


1998–2003

Tohoku University
 Department of Physics
Sendaishi, Miyagiken, Japan


1998–2001

Iowa State University
 Department of Physics and Astronomy
Ames, IA, United States


1996–1998

Northwestern University
 Department of Physics and Astronomy
Evanston, Illinois, United States
