R-Symmetric NMSSM

It is well known that the observed Higgs mass is more naturally explained in the next-to-minimal supersymmetric standard model(NMSSM)than in the minimal supersymmetric standard model.Without any violation of this success,there are variants of the NMSSM that can lead to new phenomenologies.In this study,we propose a new variant of the NMSSM by imposing an unbroken R symmetry.We first identify the minimal structure of such a scenario from the perspective of both simplicity and viability,then compare the model predictions to current experimental limits,and finally highlight the main features that differ from those of well-known scenarios.

Light Higgs boson in the NMSSM confronted with the CMS di-photon and di-tau excesses

In 2018, the CMS collaboration reported a di-photon excess at approximately 95.3 GeV with a local significance of 2.8 σ. Interestingly, the CMS collaboration also recently reported a di-tau excess at 95-100 GeV with a local significance of 2.6-3.1 σ. In addition, a bb excess at 98 GeV with a local significance of 2.3 σ was reported from LEP data approximately twenty years ago. In this study, we addressed the interpretation of these excesses together with a light Higgs boson in the next-to-minimal supersymmetric standard model(NMSSM). We conclude that, in the NMSSM, the 95-100 GeV excesses are difficult to be satisfied simultaneously(not possible globally at the 1σ level or simultaneously at the 2σ level). We analyzed two partially-satisfied scenarios: global 2σ and small di-photon. An approximate equation of global fit to the three excesses was derived, and two representative types of surviving samples were analyzed in detail. Given that the mass regions of these excesses are near the Z boson, we also checked the light Higgs boson in the tt-associated channels. The detailed results may be useful for further checking the low-mass-region excesses in the future.

Smuon in the NMSSM confronted with the muon g–2 anomaly and SUSY searches

Motivated by recent supersymmetry(SUSY)search results,which prefer most SUSY particles to be heavy,and the muon g–2 anomaly,which prefers colorless SUSY particles to be light,we explore the status of a light smuon(the SUSY partner of a left-handed muon lepton)in the next-to-minimal supersymmetric standard model(NMSSM).Assuming colored SUSY particles to be heavy,and considering numerous experimental constraints,including muon g-2,SUSY searches,and dark matter,we scan the parameter space in the NMSSM with Z3-symmetry and check the status of colorless SUSY particles and their possible mass order,paying special attention to the smuon.After calculations and discussions,we find that the surviving samples can be divided into several scenarios,where the mass region and decay information of the smuon are given.Overall,the smuon mass can be approximately 0.1~1.8 TeV.These results may be useful for smuon searches at the LHC and future colliders.

The semi-constrained NMSSM in light of muon g-2,LHC,and dark matter constraints

The semi-constrained NMSSM （scNMSSM） extends the MSSM by a singlet field, and requires unification of the soft SUSY breaking terms in the squark and slepton sectors, while it allows that in the Higgs sector to be different. We try to interpret the muon g-2 in the scNMSSM, under the constraints of 125 GeV Higgs data, B physics, searches for low and high mass resonances, searches for SUSY particles at the LHC, dark matter relic density by WMAP/Planck, and direct searches for dark matter by LUX, XENON1T, and PandaX-II. We find that under the above constraints, the scNMSSM can still （i） satisfy muon g-2 at 1α level, with a light muon sneutrino and light chargino; （ii） predict a highly-singlet-dominated 95 GeV Higgs, with a diphoton rate as hinted at by CMS data, because of a light higgsino-like chargino and moderate ）λ; （iii） get low fine tuning from the GUT scale with small μeff,M0,M1/2,andAo, with a lighter stop mass which can be as low as about 500 GeV, which can be further checked in future studies with search results from the 13 TeV LHC; （iv） have the lightest neutralino be singlino-dominated or higgsino-dominated, while the bino and wino are heavier because of high gluino bounds at the LHC and universal gaugino conditions at the GUT scale; （v） satisfy all the above constraints, although it is not easy for the lightest neutralino, as the only dark matter candidate, to get enough relic density. Several ways to increase relic density are discussed.

Pair production of Higgs boson in NMSSM at the LHC with the next-to-lightest C P-even Higgs boson being SM-like

The next-to-minimal supersymmetric standard model （NMSSM） more naturally accommodates a Higgs boson with a mass of approximately 125 GeV than the minimal supersymmetric standard model （MSSM）. In this work, we assume that the next-to-lightest CP-even Higgs boson h2 is the SM-like Higgs boson h, whereas the lightest CP-even Higgs boson h1 is dominantly singlet-like. We discuss the h1h1, h2h2, and h1h2 pair production processes via gluon-gluon fusion at the LHC for an collision energy of 14 TeV, and we consider the cases in which one Higgs boson decays to bb and the other decays to γγ or τ＋τ-. We find that, for mh1？ 62 GeV, the cross section of the gg→h1h1 process is relatively large and maximally reaches 5400 fb, and the production rate of the h1h1→bbτ＋τ-final state can reach 1500 fb, which make the detection of this final state possible for future searches of an integrated luminosity of 300 and 3000 fb-1. This is mainly due to the contributions from the resonant production process pp→h2→h1h1 and the relatively large branching ratio of h1→bb and h1→τ＋τ-. The cross sections of the pp→h2h2 and pp→h1h2 production processes maximally reach 28 fb and 133 fb, respectively.

Higgs decay to light(pseudo)scalars in the semi-constrained NMSSM

The next-to minimal supersymmetric standard model(NMSSM)with non-universal Higgs masses,i.e.,the semi-constrained NMSSM(scNMSSM),extends the minimal supersymmetric standard model(MSSM)by a singlet superfield and assumes universal conditions,except for the Higgs sector.It can not only maintain the simplicity and grace of the fully constrained MSSM and NMSSM and relieve the tension they have been facing since the discovery of the 125-GeV Higgs boson but also allow for an exotic phenomenon wherein the Higgs decay into a pair of light( 10-60GeV)singlet-dominated(pseudo)scalars(hereafter,in this paper,we use"scalar"for both scalars and pseudoscalars,considering pseudoscalars can also be called CP-odd scalars).This condition can be classified into three scenarios according to the identitiesof the SM-like Higgs and the light scalar:(i)the light scalar is CP-odd,and the SM-like Higgs is h_(2);(ii)the light scalar is CP-odd,and the SM-like Higgs is h_(1);and(iii)the light scalar is CP-even,and the SM-like Higgs is h_(2) .In this work,we compare the three scenarios,checking the interesting parameter regions that lead to the scenarios,the mixing levels of the doublets and singlets,the tri-scalar coupling between the SM-like Higgs and a pair of light scalars,the branching ratio of Higgs decay to the light scalars,and sensitivities in the detection of the exotic decay at the HL-LHC and future lepton colliders such as CEPC,FCC-ee,and ILC.Finally,several interesting conclusions are drawn,which are useful for understanding the different delicate mechanisms of the exotic decay and designing colliders in future.

Higgsino asymmetry and direct-detection constraints of light dark matter in the NMSSM with non-universal Higgs masses

In this study,we analyze the direct-detection constraints of light dark matter in the next-to minimal supersymmetric standard model(NMSSM)with non-universal Higgs masses(NUHM);we specially focus on the correlation between higgsino asymmetry and spin-dependent(SD)cross section.We draw the following conclusions.(i)The SD cross section is proportional to the square of higgsino asymmetry in dark matter X_(1)^(0)in the NMSSM-NUHM,and hence,it is small for highly singlino-dominated dark matter,(ii)The higgsino-mass parameter μeff is smaller than approximately 335 GeV in the NMSSM-NUHM due to the current muon g-2 constraint,but our scenario with light dark matter can still be alive under current constraints including the direct detection of dark matter in the spindependent channel.(iii)With a sizeable higgsino component in the light dark matter,the higgsino asymmetry and SD cross section can also be sizeable,but dark matter relic density is always small;thus,it can escape the direct detections.(iv)Light dark matter in the h_(2)-and Z-funnel annihilation channels with sufficient relic density can be covered by future LUX-ZEPLIN(LZ)7-ton in SD detections.(v)The spin-independent(SI)cross section is dominated by h_(1)-and h_(2)-exchanging channels,which can even cancel each other in some samples,leaving an SI cross section smaller by a few orders of magnitude than that of one individual channel.

Light higgsino-dominated NLSPs in semi-constrained NMSSM

In the semi-constrained next-to minimal supersymmetric standard model(scNMSSM,or NMSSM with non-universal Higgs mass)under current constraints,we consider a scenario where h2 is the SM-like Higgs,■1^0 is a singlino-dominated LSP;■1^± and ■2,3^0 are mass-degenerated,light,and higgsino-dominated next-to-lightest supersymmetric particles(NLSPs).We investigate the constraints of these NLSPs by searching for supersymmetry particles at the LHC Run-I and Run-I and discuss the possibility of discovering these NLSPs in the future.We arrive at the following conclusions:(i)With all data of Run I and up to 36 fb-1 data of Run I at the LHC,the search results by AT-LAS and CMS still cannot exclude the higgsino-dominated NLSPs of 100~200 GeV.(ii)When the mass difference with ■1^0 is smaller than ■2^0,■ and ■3^0 have opposite preferences with regard to decaying to Z/Z^* or h1.(iii)When the mass difference between NLSP and LSP is larger than mZ,most samples can be verified at the 5σ level with future 300 fb^-1 data at the LHC.Meanwhile,with 3000 fb^-1 data at high-luminosity LHC(HL-LHC),almost all of the samples can be verified at the 5σ level,even if the mass difference is insufficient.(iv)The a1 funnel and the h2/Z funnel mechanisms for the singlino-dominated LSP annihilation cannot be distinguished by searching for NLSPs.

H^± Decays into W^± and a1 in the Next Minimal Supersymmetric Standard Model

To solve the/a problem of the Minimal Supersymmetric Standard Model （MSSM）, a single field S is added to build the Next Minimal Supersymmetric Standard Model （NMSSM）. Vacuum enlarged with non-zero vevs of the neutral-even CP is the combination of Hu, Hd and S. In the NMSSM, the Higgs sector is increased to 7 （compared with 5 hogs in the MSSM）, including three Higgs-which are the even-CP hi,2,3 （mh1〈 mh2〈 mh3）, two Higgs-which are odd-CP a1,2 （ma1 〈 ma2） and a couple of charged Higgs H^±. The decays Higgs into Higgs is one of the remarkable new points of the NMSSM. In this paper, we study the decays H^± into W^± and at. The decay width is calculated to one loop vertex correction. The numerical results are also described together with evaluations.