Ulrich Ellwanger

The Next-to-Minimal Supersymmetric Standard Model

Abstract We review the theoretical and phenomenological aspects of the Next-to-Minimal Supersymmetric Standard Model: the Higgs sector including radiative corrections and the 2-loop β -functions for all parameters of the general NMSSM; the tadpole and domain wall problems, baryogenesis; NMSSM phenomenology at colliders, B physics and dark matter; specific scenarios as the constrained NMSSM, gauge mediated supersymmetry breaking, U ( 1 ) ′ -extensions, CP and R-parity violation.

Brane cosmological evolution in a bulk with cosmological constant

Abstract We consider the cosmology of a “3-brane universe” in a five dimensional (bulk) space-time with a cosmological constant. We show that Einsteins equations admit a first integral, analogous to the first Friedmann equation, which governs the evolution of the metric in the brane, whatever the time evolution of the metric along the fifth dimension. We thus obtain the cosmological evolution in the brane for any equation of state describing the matter in the brane, without needing the dependence of the metric on the fifth dimension. In the particular case p=wρ (w=constant), we give explicit expressions for the time evolution of the brane scale factor, which show that standard cosmological evolution can be obtained (after an early non conventional phase) in a scenario a la Randall and Sundrum, where a brane tension compensates the bulk cosmological constant. We also show that a tiny deviation from exact compensation leads to an effective cosmological constant at late time. Moreover, when the metric along the fifth dimension is static, we are able to extend the solution found on the brane to the whole spacetime.

SUSY Les Houches Accord 2

The Supersymmetry Les Houches Accord (SLHA) provides a universal set of conventions for conveying spectral and decay information for supersymmetry analysis problems in high energy physics. Here, we propose extensions of the conventions of the first SLHA to include various generalisations: the minimal supersymmetric standard model with violation of CP, R-parity, and flavour, as well as the simplest next-to-minimal model.

NMHDECAY: A Fortran code for the Higgs masses, couplings and decay widths in the NMSSM

The Fortran code NMHDECAY computes the masses, couplings and decay widths of all Higgs bosons of the NMSSM in terms of its parameters at the electroweak (or Susy breaking) scale: the Yukawa couplings λ and κ, the soft trilinear terms Aλ and Aκ, and tan β and μeff = λ . The computation of the spectrum includes leading two loop terms, electroweak corrections and propagator corrections. The computation of the decay widths is carried out as in HDECAY, but (for the moment) without three body decays. Each point in parameter space is checked against negative Higgs bosons searches at LEP, including unconventional channels relevant for the NMSSM. One version of the program uses generalized SLHA conventions for input and output.

NMHDECAY 2.1: An updated program for sparticle masses, Higgs masses, couplings and decay widths in the NMSSM ☆

We describe the improved properties of the NMHDECAY program, that is designed to compute Higgs and sparticle masses and Higgs decay widths in the NMSSM. In the version 2.0, Higgs decays into squarks and sleptons are included, accompanied by a calculation of the squark, gluino and slepton spectrum and tests against constraints from LEP and the Tevatron. Further radiative corrections are included in the Higgs mass calculation. A link to MicrOMEGAs allows to compute the dark matter relic density, and a rough (lowest order) calculation of BR(b→sγ) is performed. Finally, version 2.1 allows to integrate the RGEs for the soft terms up to the GUT scale.

A Higgs boson near 125 GeV with enhanced di-photon signal in the NMSSM

A bstractA natural region in the parameter space of the NMSSM can accomodate a CP-even Higgs boson with a mass of about 125 GeV and, simultaneously, an enhanced cross section times branching ratio in the di-photon channel. This happens in the case of strong singlet-doublet mixing, when the partial width of a 125 GeV Higgs boson into

Particle spectrum in supersymmetric models with a gauge singlet

b\overline b

NMSPEC: A Fortran code for the sparticle and Higgs masses in the NMSSM with GUT scale boundary conditions

is strongly reduced. In this case, a second lighter CP-even Higgs boson is potentially also observable at the LHC.

PHENOMENOLOGY OF SUPERSYMMETRIC MODELS WITH A SINGLET

We scan the complete parameter space of the supersymmetric standard model extended by a gauge singlet, which is compatible with the following constraints: universal soft supersymmetry breaking terms at the GUT scale, finite running Yukawa couplings up to the GUT scale and present experimental bounds on all sparticles, Higgs scalar and top quark. The full radiative corrections to the Higgs potential due to the top/stop sector are included. We find a lower limit on the gluino mass of 160 GeV, upper limits on the lightest neutral scalar Higgs mass dependent on mtop and the size of the soft supersymmetry breaking terms, and the possibility of a Higgs scalar as light as 10 GeV, but with reduced couplings to the Z boson.

Benchmark models, planes, lines and points for future SUSY searches at the LHC

Abstract NMSPEC is a Fortran code that computes the sparticle and Higgs masses, as well as Higgs decay widths and couplings in the NMSSM, with soft susy breaking terms specified at M GUT . Exceptions are the soft singlet mass m s 2 and the singlet self-coupling κ , that are both determined in terms of the other parameters through the minimization equations of the Higgs potential. We present a first analysis of the NMSSM parameter space with universal susy breaking terms at M GUT —except for m s and A κ —that passes present experimental constraints on sparticle and Higgs masses. We discuss in some detail a region in parameter space where a SM-like Higgs boson decays dominantly into two CP odd singlet-like Higgs states. Program summary Manuscript title: NMSPEC: A Fortran code for the sparticle and Higgs masses in the NMSSM with GUT scale boundary conditions Authors: Ulrich Ellwanger, Cyril Hugonie Program title: NMSPEC Catalogue identifier: ADZD_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADZD_v1_0.html Program obtainable from: CPC Program Library, Queens University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 121 539 No. of bytes in distributed program, including test data, etc.: 1 560 340 Distribution format: tar.gz Programming language: FORTRAN Computer: Mac, PC, Sun, Dec, Alpha Operating system: Mac OSC, Linux, Unix, Windows RAM: 2M bytes Keywords: Supersymmetry, Higgs masses, sparticle masses, NMSSM PACS: 12.60.Jv, 14.80.Cp, 14.80.Ly Classification: 11.6 Nature of problem: Computation of the Higgs and Sparticle spectrum in the NMSSM with GUT scale boundary conditions, check of theoretical and experimental constraints. Solution method: Integration of the RGEs for all couplings and mass terms from the GUT scale to the Susy scale using a modified Runge–Kutta method; computation and diagonalization of all mass matrices including up to two loop radiative corrections; computation of Higgs decay widths and branching ratios; comparison with exp. bounds from LEPII and the Tevatron. Running time: Less than 1 s per point in parameter space.