Minimal R-symmetric Supersymmetric Standard Model Research Articles

Interpreting 95 GeV di-photon/bb¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ b\\overline{b} $$\\end{document} excesses as a lightest Higgs boson of the MRSSM

The Minimal R-symmetric Supersymmetric Standard Model (MRSSM) is a well motivated BSM model which can accommodate the observed 125 GeV Higgs boson in agreement with electroweak precision observables, in particular with the W boson mass and T parameter. In the 2016 paper we showed that the SM-like 125 GeV Higgs state can be also realised as the second-to-lightest scalar of the MRSSM, leaving room for another sub-100 GeV state. Motivated by the recent ATLAS and CMS observation of the di-photon excess at a mass of around 95 GeV we investigate the possibility whether this could be the lightest CP-even MRSSM scalar in a variation of our benchmarks presented in the 2016 work. We show that such a state can also simultaneously explain the excess 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}$$ b\\overline{b} $$\\end{document} final state observed around the same mass value at LEP. Due to the R-symmetric nature of the model, a light singlet-like Higgs state leads necessarily to a light bino-singlino Dirac dark matter candidate, which can give a correct relic density while evading current experimental bounds. Dark matter and LHC searches place further bounds on this scenario and point to parameter regions which are viable and of interest for the LHC Run III and upcoming dark matter experiments.

Interpreting 95 GeV di-photon/bb¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ b\\overline{b} $$\\end{document} excesses as a lightest Higgs boson of the MRSSM

The Minimal R-symmetric Supersymmetric Standard Model (MRSSM) is a well motivated BSM model which can accommodate the observed 125 GeV Higgs boson in agreement with electroweak precision observables, in particular with the W boson mass and T parameter. In the 2016 paper we showed that the SM-like 125 GeV Higgs state can be also realised as the second-to-lightest scalar of the MRSSM, leaving room for another sub-100 GeV state. Motivated by the recent ATLAS and CMS observation of the di-photon excess at a mass of around 95 GeV we investigate the possibility whether this could be the lightest CP-even MRSSM scalar in a variation of our benchmarks presented in the 2016 work. We show that such a state can also simultaneously explain the excess 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}$$ b\\overline{b} $$\\end{document} final state observed around the same mass value at LEP. Due to the R-symmetric nature of the model, a light singlet-like Higgs state leads necessarily to a light bino-singlino Dirac dark matter candidate, which can give a correct relic density while evading current experimental bounds. Dark matter and LHC searches place further bounds on this scenario and point to parameter regions which are viable and of interest for the LHC Run III and upcoming dark matter experiments.

Rare top quark decays in the minimal R-symmetric supersymmetric standard model

The one-loop contributions to the flavor-changing neutral current decays of the top quark into a light quark and a gauge boson or Higgs boson, namely, [Formula: see text], with q being u or c, and V being [Formula: see text], g, or Z, are analyzed in this study within the framework of the minimal R-symmetric supersymmetric standard model. The charginos in this model have been separated into two sets, i.e. [Formula: see text]-chargino and [Formula: see text]-chargino. The numerical results reveal that gluino or [Formula: see text]-chargino predominantly dictate the predictions for BR ([Formula: see text]), while the impact of neutralino or [Formula: see text]-chargino contributions is insignificant. By incorporating the constraints imposed by the squark mixing parameters from [Formula: see text] and [Formula: see text], the theoretical predictions for BR([Formula: see text]) can be significantly augmented to approximately [Formula: see text]. On the other hand, the values of BR([Formula: see text]) are predicted to be at least four orders of magnitude below the current experimental limits.

Squark production with R-symmetry beyond NLO at the LHC

The Minimal R-symmetric Supersymmetric Standard Model (MRSSM) provides a realisation of supersymmetry in which the parameter space is less constrained by the current LHC data than in the simplest supersymmetric scenarios. In the present paper, we obtain the most precise theoretical predictions in the MRSSM for squark production at the LHC, enabling accurate interpretations of LHC data in terms of the MRSSM. We perform threshold resummation of soft gluon corrections to the total cross sections for the production of squark-(anti)squark pairs at the LHC in the MRSSM framework. The resummation is carried out using the direct QCD method and reaches the next-to-next-to-leading-logarithmic (NNLL) accuracy, which requires calculating the one-loop matching coefficients in the relevant production channels. The resummed cross sections are then matched to the available NLO results and evaluated for S\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\sqrt{S} $$\\end{document} = 13.6 TeV. Compared with the Minimal Supersymmetric Standard Model (MSSM), the cross sections in the MRSSM can be significantly reduced, implying less stringent limits on squark and gluino masses. Our results carry significant implications for exploring the viability of supersymmetry at the LHC. The results of our calculation are publicly available as a numerical package.

Lepton flavor violating decays of vector mesons in the MRSSM* *Supported by the Natural Science Foundation of Hebei Province (A2022104001, A2022201017), the Shanxi Scholarship Council of China (2021-31), the youth top-notch talent support program of the Hebei Province, and the Foundation of Baoding University (2018Z01)

In this study, we analyze the rare decays of the neutral vector mesons and in the scenario of the minimal R-symmetric supersymmetric standard model using the effective Lagrangian method. The predicted branching ratios are dominated by the mass insertion parameters , i.e., the off-diagonal inputs, and the contributions of different parts are comparable. Taking into account the experimental constraints on the mass insertion parameters, the predicted branching ratios for the most promising processes are ten orders of magnitude smaller than the present experimental bounds.

Searching for lepton flavor violating decays tau rightarrow Pl in the minimal R-symmetric supersymmetric standard model

We analyze the lepton flavor violating decays tau rightarrow Pl (P=pi ,eta ,eta ';;l=e,mu ) in the scenario of the minimal R-symmetric supersymmetric standard model. The prediction on the branching ratios BR(tau rightarrow P e) and BR(tau rightarrow P mu ) is affected by the mass insertion parameters delta ^{13} and delta ^{23}, respectively. These parameters are constrained by the experimental bounds on the branching ratios BR(tau rightarrow e (mu ) gamma ) and BR(tau rightarrow 3e(mu )). The result shows Z penguin dominates the prediction on BR(tau rightarrow Pl) in a large region of the parameter space. The branching ratios for BR(tau rightarrow Pl) are predicted to be, at least, five orders of magnitude smaller than present experimental bounds and three orders of magnitude smaller than future experimental sensitivities.

Muon conversion to an electron in nuclei in the minimal R-symmetric supersymmetric standard model

We analyze the lepton flavor violating process $\mu-e$ conversion in the framework of the minimal R-symmetric supersymmetric standard model. The theoretical predictions are determined by considering the experimental constraint on parameter $\delta^{12}$ from the lepton flavor violating decay $\mu\rightarrow e \gamma$. The numerical results show that $\gamma$ penguins and Z penguins dominate the predictions on CR($\mu-e$,Nucleus), and the contributions from Higgs penguins and box diagrams are insignificant. The theoretical predictions on conversion rate CR($\mu-e$,Nucleus) in a Al or Ti target can be enhanced close to the future experimental sensitivities and are very promising to be observed in near future experiment.

Lα → 3lβ in minimal R-symmetric supersymmetric Standard Model

Lepton flavor violation decays are channels which may lead to fundamental discoveries in the forthcoming years and this makes it an exciting research field for beyond the Standard Model (SM) searches. In this work, we present an analysis of the lepton flavor violation decays [Formula: see text] in Minimal R-symmetric Supersymmetric Standard Model. The prediction for [Formula: see text] depends on the off-diagonal entries of the slepton mass matrix. The contributions to Wilson coefficients can be classified into Higgs penguins, photon penguins, Z penguins and box diagrams. It shows the contribution from Z penguins dominates the predictions for [Formula: see text], and the contributions from Higgs penguins and box diagrams play different roles in different decay channels. The theoretical predictions for [Formula: see text] can reach the future experimental limits, and the channels are very promising to be observed in near future experiment.

Confronting the coloured sector of the MRSSM with LHC data

R-symmetry leads to a distinct low energy realisation of SUSY with a signicantly modified colour-charged sector featuring a Dirac gluino and scalar colour octets (sgluons). In the present work we recast results from LHC BSM searches to discuss the impact of R-symmetry on the squark and gluino mass limits. We work in the framework of the Minimal R-symmetric Supersymmetric Standard Model and take into account the NLO corrections to the squark production cross sections in the MRSSM that have become available recently. We find substantially weaker limits on squark masses compared to the MSSM: for simple scenarios with heavy gluinos and degenerate squarks, the MRSSM mass limit is {m}_{tilde{g}} > 1:7TeV, approximately 600 GeV lower than in the MSSM.

Low-energy lepton physics in the MRSSM: (g \u2212 2)\u03bc, \u03bc\u2192e\u03b3 and \u03bc\u2192e conversion

Low-energy lepton observables are discussed in the Minimal R-symmetric Supersymmetric Standard Model. We present comprehensive numerical analyses and the analytic one-loop results for (g − 2)μ, μ → eγ, and μ → e conversion. The interplay between the three observables is investigated as well as the parameter regions with large g − 2. A striking difference to the MSSM is the absence of tanβ enhancements; however we find smaller enhancements governed by MRSSM-specific R-Higgsino couplings λd and Λd. As a result we find significant contributions to g − 2 only in a small parameter space with several SUSY masses below 200 GeV, compressed spectra and large λd, Λd. In this parameter space there is a correlation between all three considered observables. In the parameter region with small (g − 2)μ the SUSY masses can be larger and the correlation between μ → eγ and μ → e conversion is weak. Therefore already COMET Phase 1 has a promising sensitivity to the MRSSM.

Precise prediction for the W boson mass in the MRSSM

The mass of the W boson, MW, plays a central role for high-precision tests of the electroweak theory. Confronting precise theoretical predictions with the accurately measured experimental value provides a high sensitivity to quantum effects of the theory entering via loop contributions. The currently most accurate prediction for the W boson mass in the Minimal R-symmetric Supersymmetric Standard Model (MRSSM) is presented. Employing the on-shell scheme, it combines all numerically relevant contributions that are known in the Standard Model (SM) in a consistent way with all MRSSM one-loop corrections. Special care is taken in the treatment of the triplet scalar vacuum expectation value vT that enters the prediction for MW already at lowest order. In the numerical analysis the decoupling properties of the supersymmetric loop contributions and the comparison with the MSSM are investigated. Potentially large numerical effects of the MRSSM-specific Λ superpotential couplings are highlighted. The comparison with existing results in the literature is discussed.

One-loop correction to Z → νν in the minimal R-symmetric supersymmetric Standard Model

We analyze the one-loop correction to [Formula: see text] decay in framework of Minimal R-symmetric Supersymmetric Standard Model (MRSSM) in detail with normal and inverse neutrino mass orderings, as a function of [Formula: see text], Dirac mass parameters [Formula: see text] and [Formula: see text], slepton mass [Formula: see text] that parametrize the mass matrices. The numerical results indicate that the branching ratio for [Formula: see text] decay is compatible with the experimental measurement and the SM expectation at [Formula: see text] level. For inverse neutrino mass ordering, the prediction exceeds the SM expectation at [Formula: see text] level. The prediction on [Formula: see text] increases proportionally to [Formula: see text] and inversely proportionally to [Formula: see text]. For normal neutrino mass ordering, the peak value of the prediction on [Formula: see text] exceeds the SM expectation at [Formula: see text] level.

LFV decays of Z boson in Minimal R-symmetric Supersymmetric Standard Model * * Supported by the National Natural Science Foundation of China (NNSFC) (11747064, 11805140), the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (2017113), the Foundation of Department of Education of Liaoning province (2016TSPY10) and the Youth Foundation of the University of Science and Technology Liaoning

A future Z-factory will offer the possibility of studying rare Z decays , such as those leading to lepton flavor violation (LFV) final states. In this work, by considering the constraints from radiative two-body decays , we investigate the LFV decays in the framework of the Minimal R-symmetric Supersymmetric Standard Model with two benchmark points from the existing literature. The flavor-violating off-diagonal entries , and are constrained by the current experimental bounds of . Considering recent experimental constraints, we also investigate Br( ) as a function of . The numerical results show that the theoretical predictions of Br( ) in the MRSSM are several orders of magnitude below the current experimental bounds. The LFV decays and may be promising observation targets in future experiments.

Confronting the Coloured Sector of the MRSSM with LHC Data

R-symmetry leads to a distinct low energy realisation of SUSY with a signicantly modified colour-charged sector featuring a Dirac gluino and scalar colour octets (sgluons). In the present work we recast results from LHC BSM searches to discuss the impact of R-symmetry on the squark and gluino mass limits. We work in the framework of the Minimal R-symmetric Supersymmetric Standard Model and take into account the NLO corrections to the squark production cross sections in the MRSSM that have become available recently. We find substantially weaker limits on squark masses compared to the MSSM: for simple scenarios with heavy gluinos and degenerate squarks, the MRSSM mass limit is $$ {m}_{\tilde{g}} $$ > 1:7TeV, approximately 600 GeV lower than in the MSSM.

Scalar color octets and triplets in the SUSY with R-symmetry

In this note we report on the recent progress in the study of the strongly interacting sector of the Minimal R-symmetric Supersymmetric Standard Model (MRSSM). First, we discuss the limits originating from the search of the sgluon pair production in the same-sign lepton final state at the LHC. Next, we present the first available in literature calculation of the NLO SQCD corrections to the same-sign squark pair production in the MRSSM. We discuss the relative size of k-factors compared to the MSSM and some technical details that led to this result.

Exploring the Higgs sector of the MRSSM with a light scalar

In a recent paper we showed that the Minimal R-symmetric Supersymmetric Standard Model (MRSSM) can accommodate the observed 125 GeV Higgs boson as the lightest scalar of the model in agreement with electroweak precision observables, in particular with the W boson mass and $T$ parameter. Here we explore a scenario with the light singlet (and bino-singlino) state in which the second-lightest scalar takes the role of the SM-like boson with mass close to 125 GeV. In such a case the second-lightest Higgs state gets pushed up via mixing already at tree-level and thereby reducing the required loop correction. Unlike in the NMSSM, the light singlet is necessarily connected with a light neutralino which naturally appears as a promising dark matter candidate. We show that dark matter and LHC searches place further bounds on this scenario and point out parameter regions, which are viable and of interest for LHC Run II and upcoming dark matter experiments.

Two-Loop Correction to the Higgs Boson Mass in the MRSSM

We present the impact of two-loop corrections on the mass of the lightest Higgs boson in the minimalR-symmetric supersymmetric standard model (MRSSM). These shift the Higgs boson mass up by typically 5 GeV or more. The dominant corrections arise from strong interactions, and from the gluon and itsN=2superpartners, the sgluon and Dirac gluino, and these corrections further increase with large Dirac gluino mass. The two-loop contributions governed purely by Yukawa couplings and the MRSSMλ,Λparameters are smaller. We also update our earlier analysis which showed that the MRSSM can accommodate the measured Higgs andWboson masses. Including the two-loop corrections increases the parameter space where the theory prediction agrees with the measurement.

Meeting Higgs and Electroweak Precision Observables with R-symmetric SUSY

The Standard Model of Particle Physics, despite its success at describing most of the available experimental data, cannot be the fundamental theory of Nature. Phenomena such as the existence of dark matter or the anomalous magnetic moment of the muon call for its extension. These questions could be addressed by supersymmetry, and for many the Minimal Supersymmetric Standard Model (MSSM) is the theory of choice. But despite a very successful Run 1, no sign of supersymmetry was found at the LHC. Therefore, one has to consider the possibility that low scale SUSY, if it is realized in Nature, might not be realized in the minimal way. This generated a lot of interest in both simple extensions of the MSSM, like the NMSSM, and more involved but arguably theoretically better motivated, like for example the Minimal R-symmetric Supersymmetric Standard Model (MRSSM). The latter one, proposed in Ref. [1] in the context of ameliorating the flavor problem of the MSSM, looks also very promising from the point of view of Higgs physics. The Higgs sector of this model was worked out in Refs. [2, 3]. This included calculations of full one-loop and partial two-loop corrections to the mass spectrum. In this work, we summarize briefly results of the two-loop analysis.

BEYOND THE MINIMAL SUPERSYMMETRIC STANDARD MODEL: FROM THEORY TO PHENOMENOLOGY

Thanks to the latest development in the field of Monte Carlo event generators and satellite programs allowing for a straightforward implementation of any beyond the Standard Model theory in those tools, studying the property of any softly-broken supersymmetric theory is become an easy task. We illustrate this statement in the context of two nonminimal supersymmetric theories, namely the Minimal Supersymmetric Standard Model with R-parity violation and the Minimal R-symmetric Supersymmetric Standard Model and choose to probe interaction vertices involving a nonstandard color structure and the sector of the top quark. We show how to efficiently implement these theories in the MATHEMATICA package FEYNRULES and use its interfaces to Monte Carlo tools for phenomenological studies. For the latter, we employ the latest version of the MADGRAPH program.

Neutrino mass, sneutrino dark matter and signals of lepton flavor violation in the MRSSM

We study the phenomenology of mixed-sneutrino dark matter in the Minimal R-Symmetric Supersymmetric Standard Model (MRSSM). Mixed sneutrinos fit naturally within the MRSSM, as the smallness (or absence) of neutrino Yukawa couplings singles out sneutrino A-terms as the only ones not automatically forbidden by R-symmetry. We perform a study of randomly generated sneutrino mass matrices and find that (i) the measured value of $\Omega_{DM}$ is well within the range of typical values obtained for the relic abundance of the lightest sneutrino, (ii) with small lepton-number-violating mass terms $m_{nn}^{2} {\tilde n} {\tilde n}$ for the right-handed sneutrinos, random matrices satisfying the $\Omega_{DM}$ constraint have a decent probability of satisfying direct detection constraints, and much of the remaining parameter space will be probed by upcoming experiments, (iii) the $m_{nn}^{2} {\tilde n} {\tilde n}$ terms radiatively generate appropriately small Majorana neutrino masses, with neutrino oscillation data favoring a mostly sterile lightest sneutrino with a dominantly mu/tau-flavored active component, and (iv) a sneutrino LSP with a significant mu component can lead to striking signals of e-mu flavor violation in dilepton invariant-mass distributions at the LHC.