We update constraints from B physics observables on the parameters of the MSSM and the NMSSM, combining them with LEP constraints. Presently available SM and Susy radiative corrections are included in the calculations, which will be made public in the form of a Fortran code. Results for the tan β and M H ± dependence of BR(B → X s γ) are presented, as well as constraints on the NMSSM specific case of a light CP odd Higgs scalar. We find that the latter are essentially due to BR(B s → µ + µ − ), but they do not exclude this possibility. * It is well known that rare decays and/or oscillations of B-Mesons impose constraints on the parameter space of models Beyond the Standard Model (BSM): BSM contributions are not necessarily suppressed, once the dominant contributions both in the SM and BSM arise from loop diagrams (or are even absent in the SM).Recently, considerable progress has been made both on the experimental side (such as improved measurements of small branching ratios) and on the theoretical side, i.e. improved evaluations of SM predictions and BSM contributions.The purpose of the present paper is to study the resulting constraints on the parameter space of supersymmetric extensions of the standard model, both in the MSSM and theIn the MSSM, similar analyses have recently been performed in [1][2][3][4] (see also refs. [5-10] for recent discussions within the Minimal Flavour Violating MSSM).In [1,2] the new experimental B physics results have been used to constrain the parameter space of the MSSM. In [3] it has been argued, that the new results on BR(B + → τ + ν τ ) are evidence for BSM contributions. A general χ 2 fit has been performed in [4] in the context of the CMSSM (with universal Susy-breaking terms at the GUT scale) and the NUHM (with non-universal Higgs mass terms), together with constraints on the dark matter relic density.One purpose of the present paper is to consider constraints from BR(B → X s γ) on the NMSSM. Our result is that the NMSSM specific effects on BR(B → X s γ) are rather weak: in the NMSSM the charged Higgs mass squared receives (at tree level) a negative contribution relative to the MSSM which lowers its mass somewhat; once the result of BR(B → X s γ) is plotted against M H ± , no difference between the MSSM and the NMSSM remains visible, however. Two loop corrections (relevant at large tan β) are sensitive to the neutralino sector which includes the singlino in the NMSSM; we find, however, that even for relatively large singlino -MSSM-like-neutralino mixings the NMSSM specific numerical effect on BR(B → X s γ) is numerically negligible. (Combined constraints on the parameter space of the NMSSM from LEP, the dark matter relic density and B physics -but without the recent developments in B physics -have been investigated previously in [11,12].) Note that in the general MSSM, LEP constraints on the lightest Higgs mass impose tan β > ∼ 3 (or tan β > ∼ 10 in the CMSSM). In the NMSSM (and the CNMSSM), LEP constraints on Higgs masses and couplings allow for rather low values of tan β [...

The Next-to-Minimal Supersymmetric Standard model (NMSSM) appears as an interesting candidate for the interpretation of the Higgs measurement at the LHC and as a rich framework embedding physics beyond the Standard Model. We consider the renormalization of the Higgs sector of this model in its CP-violating version, and propose a renormalization scheme for the calculation of on-shell Higgs masses. Moreover, the connection between the physical states and the tree-level ones is no longer trivial at the radiative level: a proper description of the corresponding transition thus proves necessary in order to calculate Higgs production and decays at a consistent loop order. After discussing these formal aspects, we compare the results of our mass calculation to the output of existing tools. We also study the relevance of the on-shell transition matrix in the example of the h i → τ + τ − width. We find deviations between our full prescription and popular approximations that can exceed 10%.

In models with an extended Higgs sector, such as the (N)MSSM, scalar states mix with one another. Yet, the concept of Higgs mixing is problematic at the radiative level, since it introduces both a scheme and a gauge dependence. In particular, the definition of Higgs masses and decay amplitudes can be impaired by the presence of gauge-violating pieces of higher order. We discuss in depth the origin and magnitude of such effects and consider two strategies that minimize the dependence on the gauge-fixing parameter and field-renormalization of one-loop order in the definition of the mass and decay observables, both in degenerate and non-degenerate scenarios. In addition, the intuitive concept of mixing and the simplicity of its definition in terms of two-point diagrams can make it tempting to include higher-order corrections on this side of the calculation, irrespectively of the order achieved in vertex diagrams. Using the global $$SU(2)_{\mathrm{L}}$$ S U ( 2 ) L -symmetry in the decoupling limit, we show that no improvement can be expected from such an approach at the level of the Higgs decays, but that, on the contrary, the higher-order terms may lead to numerically large spurious effects.

The mass of the eta(b)(1S), measured recently by the BABAR Collaboration, is significantly lower than expected from QCD predictions for the Upsilon(1S)-eta(b)(1S) hyperfine splitting. We suggest that the observed eta(b)(1S) mass is shifted downwards due to a mixing with a CP-odd Higgs boson A with a mass m(A) in the range 9.4-10.5 GeV compatible with LEP, CLEO, and BABAR constraints. We determine the resulting predictions for the spectrum of the eta(b)(nS)-A system and the branching ratios into tau(+)tau(-) as functions of m(A).

We study possible effects of a light CP-odd Higgs boson on radiative Υ decays in the Next-to-Minimal Supersymmetric Standard Model. Recent constraints from CLEO on radiative Υ(1S) decays are translated into constraints on the parameter space of CP-odd Higgs boson masses and couplings, and compared to constraints from B physics and the muon anomalous magnetic moment. Possible Higgs-η b (nS) mixing effects are discussed, notably in the light of the recent measurement of the η b (1S) mass by Babar: The somewhat large Υ(1S) -η b (1S) hyperfine splitting could easily be explained by the presence of a CP-odd Higgs boson with a mass in the range 9.4 -10.5 GeV. Then, tests of lepton universality in inclusive radiative Υ decays can provide a visible signal in forthcoming experimental data.

Predictions for the Higgs masses are a distinctive feature of supersymmetric extensions of the Standard Model, where they play a crucial role in constraining the parameter space. The discovery of a Higgs boson and the remarkably precise measurement of its mass at the LHC have spurred new efforts aimed at improving the accuracy of the theoretical predictions for the Higgs masses in supersymmetric models. The “Precision SUSY Higgs Mass Calculation Initiative” (KUTS) was launched in 2014 to provide a forum for discussions between the different groups involved in these efforts. This report aims to present a comprehensive overview of the current status of Higgs-mass calculations in supersymmetric models, to document the many advances that were achieved in recent years and were discussed during the KUTS meetings, and to outline the prospects for future improvements in these calculations.

The Next-to-Minimal Supersymmetric Standard Model (NMSSM) offers a rich framework embedding physics beyond the Standard Model as well as consistent interpretations of the results about the Higgs signal detected at the LHC. We investigate the decays of neutral Higgs states into Standard Model (SM) fermions and gauge bosons. We perform full one-loop calculations of the decay widths and include leading higher-order QCD corrections. We first discuss the technical aspects of our approach, before confronting our predictions to those of existing public tools, performing a numerical analysis and discussing the remaining theoretical uncertainties. In particular, we find that the decay widths of doublet-dominated heavy Higgs bosons into electroweak gauge bosons are dominated by the radiative corrections, so that the tree-level approximations that are often employed in phenomenological analyses fail. Finally, we focus on the phenomenological properties of a mostly singlet-like state with a mass below the one at 125 GeV, a scenario that appears commonly within the NMSSM. In fact, the possible existence of a singlet-dominated state in the mass range around or just below 100 GeV would have interesting phenomenological implications. Such a scenario could provide an interpretation for both the 2.3 σ local excess observed at LEP in the e + e − → Z (H → bb) searches at ∼ 98 GeV and for the local excess in the diphoton searches recently reported by CMS in this mass range, while at the same time it would reduce the "Little Hierarchy" problem.

Abstract:We generalize the computation of supersymmetric contributions to the muon anomalous magnetic moment (g − 2) µ to the NMSSM. In the presence of a light CP-odd Higgs scalar, these can differ considerably from the MSSM. We discuss the amount of these contributions in regions of the parameter space of the general NMSSM compatible with constraints from B physics. In the mSUGRA-like cNMSSM, constraints from (g − 2) µ prefer regions in parameter space corresponding to a low SUSY breaking scale.