NMSSM Research Articles

NMSSM explanation for excesses in the search for neutralinos and charginos and a 95 GeV Higgs boson

The observed excesses in the search for neutralinos and charginos by ATLAS and CMS can be fitted simultaneously in the minimal supersymmetric standard model (MSSM) assuming a light higgsino mass, of magnitude less than about 250 GeV, and a compressed higgsino dominated neutralino and chargino spectrum, with 5–10% mass splittings. However, light higgsinos as dark matter would have far too large direct detection cross sections. We consider the Next-to-MSSM (NMSSM) with an additional singlino-like lightest supersymmetric particle (LSP) a few GeV below the next-to-lightest supersymmetric particle (NLSP). Sparticles prefer to decay first into the NLSP and remnants from the final decay into the LSP are too soft to contribute to the observed signals. Co-annihilation in the higgsino-sector can generate a relic density in the WMAP/Planck window. The singlino-like LSP has automatically a direct detection cross section below present and future sensitivities: a direct detection signal in the near future would exclude this scenario. The singlet-like Higgs scalar of the NMSSM can have a mass around 95 GeV and signal cross sections in the bb¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$b\\bar{b}$$\\end{document} channel at LEP and in the γγ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma \\gamma $$\\end{document} channel at the LHC compatible with the respective observations.

Dark Matter searches with photons at the LHC

We unveil blind spot regions in dark matter (DM) direct detection (DMDD), for weakly interacting massive particles with a mass around a few hundred GeV that may reveal interesting photon signals at the LHC. We explore a scenario where the DM primarily originates from the singlet sector within the Z3-symmetric Next-to-Minimal Supersymmetric Standard Model (NMSSM). A novel DMDD spin-independent blind spot condition is revealed for singlino-dominated DM, in cases where the mass parameters of the higgsino and the singlino-dominated lightest supersymmetric particle (LSP) exhibit opposite relative signs (i.e., κ < 0), emphasizing the role of nearby bino and higgsino-like states in tempering the singlino-dominated LSP. Additionally, proximate bino and/or higgsino states can act as co-annihilation partner(s) for singlino-dominated DM, ensuring agreement with the observed relic abundance of DM. Remarkably, in scenarios involving singlino-higgsino co-annihilation, higgsino-like neutralinos can distinctly favor radiative decay modes into the singlino-dominated LSP and a photon, as opposed to decays into leptons/hadrons. In exploring this region of parameter space within the singlino-higgsino compressed scenario, we study the signal associated with at least one relatively soft photon alongside a lepton, accompanied by substantial missing transverse energy (ɆT) and a hard initial state radiation jet at the LHC. In the context of singlino-bino co-annihilation, the bino state, as the next-to-LSP, exhibits significant radiative decay into a soft photon and the LSP, enabling the possible exploration at the LHC through the triggering of this soft photon alongside large ɆT and relatively hard leptons/jets resulting from the decay of heavier higgsino-like states.

Light Higgs boson in the NMSSM confronted with the CMS di-photon and di-tau excesses* *Supported by the National Natural Science Foundation of China (12275066, 11605123, 11547103, 12074295)

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 GeV with a local significance of . In addition, a 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 GeV excesses are difficult to be satisfied simultaneously (not possible globally at the level or simultaneously at the level). We analyzed two partially-satisfied scenarios: global 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 -associated channels. The detailed results may be useful for further checking the low-mass-region excesses in the future.

Probing the impact of WIMP dark matter on universal relations, GW170817 posterior, and radial oscillations

ABSTRACT In this study, we investigate the impact of weakly interacting massive particles (WIMPs) dark matter (DM) on C–Λ universal relations, GW170817 posterior, and radial oscillations of neutron stars (NSs) by considering the interactions of uniformly trapped neutralinos as a DM candidate with the hadronic matter through the exchange of the Higgs boson within the framework of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The hadronic equation of state (EOS) is modelled using the relativistic mean-field (RMF) formalism with IOPB-I, G3, and quark–meson coupling (QMC)-RMF series parameter sets. The presence of DM softens the EOS at both the background and the perturbation levels that implies a small shift to the left in the posterior accompanied by a much larger jump in the left of the mass–radius curves with increasing DM mass. It is observed that EOSs with DM also satisfy the C–Λ universality relations among themselves but get slightly shifted to the right in comparison to that without considering DM. Additionally, we find that the inclusion of DM allows the mass–radius (M–R) curves to remain consistent with observational constraints for HESS J1731−347, indicating the possibility of classifying it as a dark matter-admixed neutron star (DMANS). Moreover, we explore the impact of DM on the radial oscillations of pulsating stars and investigate the stability of NSs. The results demonstrate a positive correlation between the mass of DM and the frequencies of radial oscillation modes.

Electroweak phase transition in a right-handed neutrino superfield extended NMSSM

Supersymmetric models with singlet extensions can accommodate single- or multi-step first-order phase transitions (FOPT) along the various constituent field directions. Such a framework can also produce Gravitational Waves, detectable at the upcoming space-based interferometers, e.g., U-DECIGO. We explore the dynamics of electroweak phase transition and the production of Gravitational Waves in an extended set-up of the Next-to-Minimal Supersymmetric Standard Model (NMSSM) with a Standard Model singlet right-handed neutrino superfield. We examine the role of the new parameters compared to NMSSM on the phase transition dynamics and observe that the occurrence of a FOPT, an essential requirement for Electroweak Baryogenesis, typically favours a right-handed sneutrino state below 125 GeV. Our investigation shows how the analysis can offer complementary probes for physics beyond the Standard Model besides the collider searches.

Explaining the Muon g − 2 Anomaly in Deflected AMSB for NMSSM

We propose to embed the General NMSSM (Next-to-Minimal Supersymmetric Standard Model) into the deflected AMSB (Anomaly Mediated Supersymmetry Breaking) mechanism with Yukawa/gauge deflection contributions. After the integration of the heavy messenger fields, the analytical expressions of the relevant soft SUSY breaking spectrum for General NMSSM at the messenger scale can be calculated. We find that successful EWSB (Electroweak Symmetry Breaking) and realistic low energy NMSSM spectrum can be obtained in some parameter regions. In addition, we find that the muon g−2 anomaly and electron g−2 anomaly (for positive central value electron g−2 experimental data) can be jointly explained to 1σ and 2σ range, respectively. The Z3 invariant NMSSM, which corresponds to ξF=0 in our case, can also jointly explain the muon and electron anomaly to 1σ and 2σ range, respectively.

Right-handed sneutrino and gravitino multicomponent dark matter in light of neutrino detectors

We investigate the possibility that right-handed (RH) sneutrinos and gravitinos can coexist and explain the dark matter (DM) problem. We compare extensions of the minimal supersymmetric standard model (MSSM) and the next-to-MSSM (NMSSM) adding RH neutrinos superfields, with special emphasis on the latter. If the gravitino is the lightest supersymmetric particle (LSP) and the RH sneutrino the next-to-LSP (NLSP), the heavier particle decays to the former plus left-handed (LH) neutrinos through the mixing between the scalar partners of the LH and RH neutrinos.However, the interaction is suppressed by the Planck mass, and if the LH-RH sneutrino mixing parameter is small, ≪ O(10-2), a long-lived RH sneutrino NLSP is possible even surpassing the age of the Universe.As a byproduct, the NLSP to LSP decay produces monochromatic neutrinos in the ballpark of current and planned neutrino telescopes like Super-Kamiokande, IceCube and Antares that we use to set constraints and show prospects of detection.In the NMSSM+RHN, assuming a gluino mass parameter M 3 = 3 TeV we found the following lower limits for the gravitino mass m 3/2 ≳ 1-600 GeV and the reheating temperature T R ≳ 105 - 3 × 107 GeV, for mν̃ R 10-800 GeV. If we take M 3 = 10 TeV, then the limits on TR are relaxed by one order of magnitude.

Status of the singlino-dominated dark matter in general Next-to-Minimal Supersymmetric Standard Model

With the rapid progress of dark matter direct detection experiments, the attractiveness of the popular bino-dominated dark matter in economical supersymmetric theories is fading. As an alternative, the singlino-dominated dark matter in general Next-to-Minimal Supersymmetric Standard Model (NMSSM) is paying due attention. This scenario has the following distinct characteristics: free from the tadpole problem and the domain-wall problem of the NMSSM with a Z3-symmetry, predicting more stable vacuum states than the Z3-NMSSM, capable of forming an economical secluded dark matter sector to yield the dark matter experimental results naturally, and readily weaken the restrictions from the LHC search for SUSY. Consequently, it can explain the muon g-2 anomaly in broad parameter space that agrees with various experimental results while simultaneously breaking the electroweak symmetry naturally. In this study, we show in detail how the scenario coincides with the experiments, such as the SUSY search at the LHC, the dark matter search by the LZ experiment, and the improved measurement of the muon g-2. We provide a simple and clear picture of the physics inherent in the general NMSSM.

The Phenomenological Research on Higgs and Dark Matter in the Next-to-Minimal Supersymmetric Standard Model

The Z3-invariant next-to-minimal supersymmetric standard model (NMSSM) can provide a candidate for dark matter (DM). It can also be used to explain the hypothesis that the Higgs signal observed on the Large Hadron Collider (LHC) comes from the contribution of the two lightest CP-even Higgs bosons, whose masses are near 125 GeV. At present, XENON1T, LUX, and PandaX experiments have imposed very strict restrictions on direct collision cross sections of dark matter. In this paper, we consider a scenario that the observed Higgs signal is the superposition of two mass-degenerate Higgs in the Z3-invariant NMSSM and scan the seven-dimension parameter space composing of λ,κ,tanβ,μ,Ak,At,M1 via the Markov chain Monte Carlo (MCMC) method. We find that the DM relic density, as well as the LHC searches for sparticles, especially the DM direct detections, has provided a strong limit on the parameter space. The allowed parameter space is featured by a relatively small μ≤300 GeV and about tanβ∈(10,20). In addition, the DM is Higgsino-dominated because of |2κλ|&gt;1. Moreover, the co-annihilation between χ˜10 and χ˜1± must be taken into account to obtain the reasonable DM relic density.

Dilution of dark matter relic density in singlet extension models

We study the dilution of dark matter (DM) relic density caused by the electroweak first-order phase transition (FOPT) in the singlet extension models, including the singlet extension of the standard model (xSM), of the two-Higgs-doublet model (2HDM+S) and the next-to-minimal supersymmetric standard model (NMSSM). We find that in these models the entropy released by the strong electroweak FOPT can dilute the DM density to 1/3 at most. Nevertheless, in the xSM and NMSSM where the singlet field configure is relevant to the phase transition temperature, the strong FOPT always happens before the DM freeze-out, making the dilution effect negligible for the current DM density. We derive an analytical upper bound on the freeze-out temperature and a numerical lower bound on nucleation temperature in the xSM. On the other hand, in the 2HDM+S where the DM freeze-out temperature is independent of FOPT, the dilution may salvage some parameter space excluded by excessive DM relic density or by DM direct detections.

R-Symmetric NMSSM* *Supported in part by the National Natural Science Foundation of China (11775039), the High-level Talents Research and Startup Foundation Projects for Doctors of Zhoukou Normal University (ZKNUC2021006), and Scientific research projects of universities in Henan Province, China (23A140027).

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.

Smuon in the NMSSM confronted with the muon g–2 anomaly and SUSY searches* *Supported by the National Natural Science Foundation of China (NNSFC, 11605123)

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 -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.

Electroweak phase transition in the Z3-invariant NMSSM: Implications of LHC and Dark matter searches and prospects of detecting the gravitational waves

We study in detail the viability and the patterns of a strong first-order electroweak phase transition as a prerequisite to electroweak baryogenesis in the framework of Z3-invariant Next-to-Minimal Supersymmetric Standard Model (NMSSM), in the light of recent experimental results from the Higgs sector, dark matter (DM) searches and those from the searches of the lighter chargino and neutralinos at the Large Hadron Collider (LHC). For the latter, we undertake thorough recasts of the relevant, recent LHC analyses. With the help of a few benchmark scenarios, we demonstrate that while the LHC has started to eliminate regions of the parameter space with relatively small μeff, that favors the coveted strong first-order phase transition, rather steadily, there remains phenomenologically much involved and compatible regions of the same which are yet not sensitive to the current LHC analyses. It is further noted that such a region could also be compatible with all pertinent theoretical and experimental constraints. We then proceed to analyze the prospects of detecting the stochastic gravitational waves, which are expected to arise from such a phase transition, at various future/proposed experiments, within the mentioned theoretical framework and find them to be somewhat ambitious under the currently projected sensitivities of those experiments.

Possible indications for new Higgs bosons in the reach of the LHC: N2HDM and NMSSM interpretations

In several searches for additional Higgs bosons at the LHC, in particular in a CMS search exploring decays to pairs of top quarks, tbar{t}, and in an ATLAS search studying tau leptons, tau ^+tau ^-, local excesses of about 3,sigma standard deviations or above have been observed at a mass scale of approximately 400 ,text {GeV}. We investigate to what extent a possible signal in these channels could be accommodated in the Next-to-Two-Higgs-Doublet Model (N2HDM) or the Next-to Minimal Supersymmetric Standard Model (NMSSM). In a second step we analyze whether such a model could be compatible with both a signal at around 400,text {GeV} and 96,text {GeV}, where the latter possibility is motivated by observed excesses in searches for the b bar{b} final state at LEP and the di-photon final state at CMS. The analysis for the N2HDM reveals that the observed excesses at 400 ,text {GeV} in the tbar{t} and tau ^+tau ^- channels point towards different regions of the parameter space, while one such excess and an additional Higgs boson at around 96,text {GeV} could simultaneously be accommodated. In the context of the NMSSM an experimental confirmation of a signal in the tbar{t} final state would favour the alignment-without-decoupling limit of the model, where the Higgs boson at 125,text {GeV} could be essentially indistinguishable from the Higgs boson of the standard model. In contrast, a signal in the tau ^+tau ^- channel can only be accommodated outside of this limit, and parts of the investigated parameter space could be probed with Higgs signal-rate measurements at the (HL-)LHC.

Two-loop mathcal{O} ((\u03b1t + \u03b1\u03bb + \u03b1\u03ba)2) corrections to the Higgs boson masses in the CP-violating NMSSM

We present our computation of the mathcal{O} ((αt + αλ + ακ)2) two-loop corrections to the Higgs boson masses of the CP-violating Next-to-Minimal Supersymmetric Standard Model (NMSSM) using the Feynman-diagrammatic approach in the gaugeless limit at vanishing external momentum. We choose a mixed overline{mathrm{DR}} -on-shell (OS) renormalisation scheme for the Higgs sector and apply both overline{mathrm{DR}} and OS renormalisation in the top/stop sector. For the treatment of the infrared divergences we apply and compare three different regularisation methods: the introduction of a regulator mass, the application of a small momentum expansion, and the inclusion of the full momentum dependence. Our new corrections have been implemented in the Fortran code NMSSMCALC that computes the Higgs mass spectrum of the CP-conserving and CP-violating NMSSM as well as the Higgs boson decays including the state-of-the-art higher-order corrections. Our numerical analysis shows that the newly computed corrections increase with rising λ and κ, remaining overall below about 3% compared to our previously computed mathcal{O} (αt(αt + αs)) corrections, in the region compatible with perturbativity below the GUT scale. The renormalisation scheme and scale dependence is of typical two-loop order. The impact of the CP-violating phases in the new corrections is small. We furthermore show that the Goldstone Boson Catastrophe due to the infrared divergences can be treated in a numerically efficient way by introducing a regulator mass that approximates the momentum-dependent results best for squared mass values in the permille range of the squared renormalisation scale. Our results mark another step forward in the program of increasing the precision in the NMSSM Higgs boson observables.

A common origin of muon g-2 anomaly, Galaxy Center GeV excess and AMS-02 anti-proton excess in the NMSSM

The supersymmetric model is one of the most attractive extensions of the Standard Model of particle physics. In light of the most recently reported anomaly of the muon g-2 measurement by the FermiLab E989 experiment, and the excesses of gamma rays at the Galactic center observed by Fermi-LAT space telescope, as well as the antiproton excess observed by the Alpha Magnetic Spectrometer, we propose to account for all these anomalies or excesses in the Next-to-Minimal Supersymmetric Standard Model (NMSSM). Considering various experimental constraints including the Higgs mass, B-physics, collider data, dark matter relic density and direct detections, we find that a ~60 GeV bino-like neutralino is able to successfully explain all these observations. Our scenario can be sensitively probed by future direct detection experiments.

Singlino-dominated dark matter in general NMSSM

The general Next-to-Minimal Supersymmetric Standard Model (NMSSM) describes the singlino-dominated dark-matter (DM) property by four independent parameters: singlet-doublet Higgs coupling coefficient λ, Higgsino mass μtot, DM mass {m}_{{tilde{chi}}_1^0} , and singlet Higgs self-coupling coefficient κ. The first three parameters strongly influence the DM-nucleon scattering rate, while κ usually affects the scattering only slightly. This characteristic implies that singlet-dominated particles may form a secluded DM sector. Under such a theoretical structure, the DM achieves the correct abundance by annihilating into a pair of singlet-dominated Higgs bosons by adjusting κ’s value. Its scattering with nucleons is suppressed when λv/μtot is small. This speculation is verified by sophisticated scanning of the theory’s parameter space with various experiment constraints considered. In addition, the Bayesian evidence of the general NMSSM and that of Z3-NMSSM is computed. It is found that, at the cost of introducing one additional parameter, the former is approximately 3.3 × 103 times the latter. This result corresponds to Jeffrey’s scale of 8.05 and implies that the considered experiments strongly prefer the general NMSSM to the Z3-NMSSM.

A relatively light, highly bino-like dark matter in the Z3-symmetric NMSSM and recent LHC searches

A highly bino-like Dark Matter (DM), which is the Lightest Supersymmetric Particle (LSP), could be motivated by the stringent upper bounds on the DM direct detection rates. This is especially so when its mass is around or below 100 GeV for which such a bound tends to get most severe. Requiring not so large a higgsino mass parameter, that would render the scenario reasonably ‘natural’, prompts such a bino-like state to be relatively light. In the Minimal Supersymmetric Standard Model (MSSM), in the absence of comparably light scalars, such an excitation, if it has to be a thermal relic, is unable to meet the stringent experimental upper bound on its abundance unless its self-annihilation hits a funnel involving either the Z-boson or the Standard Model (SM)-like Higgs boson. We demonstrate that, in such a realistic situation, a highly bino-like DM of the popular Z3-symmetric Next-to-Minimal Supersymmetric Standard Model (NMSSM) is viable over an extended range of its mass, from our targeted maximum in the vicinity of the mass of the top quark down to about 30 GeV. This is facilitated by the presence of comparably light singlet-like states that could serve as funnel (scalars) and/or coannihilating (singlino) states even as the bino-like LSP receives a minimal (but optimal) tempering triggered by suitably light higgsino states that, in the first place, evade stringent lower bounds on their masses that can be derived from the Large Hadron Collider (LHC) experiments only in the presence of a lighter singlino-like state. An involved set of blind spot conditions is derived for the DM direct detection rates by considering for the very first time the augmented system of neutralinos comprising of the bino, the higgsinos and the singlino which highlights the important roles played by the NMSSM parameters ‘λ’ and tan β in delivering a richer phenomenology.

Dark matter candidates in the NMSSM with RH neutrino superfields

R-parity conserving supersymmetric models with right-handed (RH) neutrinos are very appealing since they could naturally explain neutrino physics and also provide a good dark matter (DM) candidate such as the lightest supersymmetric particle (LSP). In this work we consider the next-to-minimal supersymmetric standard model (NMSSM) plus RH neutrino superfields, with effective Majorana masses dynamically generated at the electroweak scale (EW). We perform a scan of the relevant parameter space and study both possible DM candidates: RH sneutrino and neutralino. Especially for the case of RH sneutrino DM we analyse the intimate relation between both candidates to obtain the correct amount of relic density.Besides the well-known resonances, annihilations through scalar quartic couplings and coannihilation mechanisms with all kind of neutralinos, are crucial. Finally, we present the impact of current and future direct and indirect detection experiments on both DM candidates.

Higgsino asymmetry and direct-detection constraints of light dark matter in the NMSSM with non-universal Higgs masses * *Supported by the National Natural Science Foundation of China (11605123)

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 in the NMSSM-NUHM, and hence, it is small for highly singlino-dominated dark matter. (ii) The higgsino-mass parameter is smaller than approximately 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 spin-dependent 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 - 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 - and -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.