Florian Domingo

Updated constraints from B physics on the MSSM and the NMSSM

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(beta) and M_{H^+} dependence of b -> s gamma 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 B_s -> mu^+ mu^-, but they do not exclude this possibility.

Radiative Upsilon decays and a light pseudoscalar Higgs in the NMSSM

We study possible effects of a light CP-odd Higgs boson on radiative Upsilon decays in the Next-to-Minimal Supersymmetric Standard Model. Recent constraints from CLEO on radiative Upsilon(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 - eta_b(nS) mixing effects are discussed, notably in the light of the recent measurement of the eta_b(1S) mass by Babar: The somewhat large Upsilon(1S) - eta_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 Upsilon decays can provide a visible signal in forthcoming experimental data.

Constraints from the muon g−2 on the parameter space of the NMSSM

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.

Bottomonium Spectroscopy with Mixing of eta{sub b} States and a Light CP-Odd Higgs Boson

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).

Bottomonium spectroscopy with mixing of eta_b states and a light CP-odd Higgs

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).

Radiative Υ decays and a light pseudoscalar Higgs in the NMSSM

We study possible effects of a light CP-odd Higgs boson on radiative Upsilon decays in the Next-to-Minimal Supersymmetric Standard Model. Recent constraints from CLEO on radiative Upsilon(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 - eta_b(nS) mixing effects are discussed, notably in the light of the recent measurement of the eta_b(1S) mass by Babar: The somewhat large Upsilon(1S) - eta_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 Upsilon decays can provide a visible signal in forthcoming experimental data.

NMSSM interpretations of the observed Higgs signal

A bstractWhile the properties of the signal that was discovered in the Higgs searches at the LHC are consistent so far with the Higgs boson of the Standard Model (SM), it is crucial to investigate to what extent other interpretations that may correspond to very different underlying physics are compatible with the current results. We use the Next-to-Minimal Supersymmetric Standard Model (NMSSM) as a well-motivated theoretical framework with a sufficiently rich Higgs phenomenology to address this question, making use of the public tools HiggsBounds and HiggsSignals in order to take into account comprehensive experimental information on both the observed signal and on the existing limits from Higgs searches at LEP, the TeVatron and the LHC. We find that besides the decoupling limit resulting in a single light state with SM-like properties, several other configurations involving states lighter or quasi-degenerate with the one at about 125 GeV turn out to give a competitive fit to the Higgs data and other existing constraints. We discuss the phenomenology and possible future experimental tests of those scenarios, and compare the features of specific scenarios chosen as examples with those arising from a more global fit.

A new tool for the study of the CP-violating NMSSM

A bstractSupersymmetric extensions of the Standard Model open up the possibility for new types of CP-violation. We consider the case of the Next-to-Minimal Supersymmetric Standard Model where, beyond the phases from the soft lagrangian, CP-violation could enter the Higgs sector directly at tree-level through complex parameters in the superpotential. We develop a series of Fortran subroutines, cast within the public tool NMSSMTools and allowing for a phenomenological analysis of the CP-violating NMSSM. This new tool performs the computation of the masses and couplings of the various new physics states in this model: leading corrections to the sparticle masses are included; the precision for the Higgs masses and couplings reaches the full one-loop and leading two-loop order. The two-body Higgs and top decays are also attended. We use the public tools HiggsBounds and HiggsSignals to test the Higgs sector. Additional subroutines check the viability of the sparticle spectrum in view of LEP-limits and constrain the phases of the model via a confrontation to the experimentally measured Electric Dipole Moments. These tools will be made publicly available in the near future. In this paper, we detail the workings of our code and illustrate its use via a comparison with existing results. We also consider some consequences of CP-violation for the NMSSM Higgs sector.

More on the hypercharge portal into the dark sector

A bstractIf the hidden sector contains more than one U(1) groups, additional dim-4 couplings (beyond the kinetic mixing) between the massive U(1) fields and the hypercharge generally appear. These are of the form similar to the Chern-Simons interactions. We study the phenomenology of such couplings including constraints from laboratory experiments and implications for dark matter. The hidden vector fields can play the role of dark matter whose characteristic signature would be monochromatic gamma ray emission from the galactic center. We show that this possibility is consistent with the LHC and other laboratory constraints, as well as astrophysical bounds.

CDF MULTI-MUON EVENTS AND SINGLET EXTENSIONS OF THE MSSM

We discuss a generalization of the minimal supersymmetric extension of the Standard Model in the form of three additional singlet superfields, which would explain the essential features of the CDF multi-muon events presented recently: a large production cross section of ~ 100 pb originates from the production of a CP-odd scalar A with a mass in the 70–80 GeV range and a large value of tan β ~ 40. The CP-odd scalar A decays dominantly into CP-odd and CP-even scalars a1 and h1, which generate decay cascades h1 → 2h2 → 4a2 → 8τ, and a1 → h1 a2 with h1 decaying as above. The decay a2 → τ+τ- is slow, leading to a lifetime of