Arne M. Weber

Prediction for the lightest Higgs boson mass in the CMSSM using indirect experimental constraints

Abstract Measurements at low energies provide interesting indirect information about masses of particles that are (so far) too heavy to be produced directly. Motivated by recent progress in consistently and rigorously calculating electroweak precision observables and flavour related observables, we derive the preferred value for m h in the Constrained Minimal Supersymmetric Standard Model (CMSSM), obtained from a fit taking into account electroweak precision data, flavour physics observables and the abundance of cold dark matter. No restriction is imposed on m h itself: the experimental bound from direct Higgs boson search at LEP is not included in the fit. A multi-parameter χ 2 is minimized with respect to the free parameters of the CMSSM, M 0 , M 1 / 2 , A 0 , tan β . A statistical comparison with the Standard Model fit to the electroweak precision data is made. The preferred value for the lightest Higgs boson mass in the CMSSM is found to be m h CMSSM = 110 −10 +8 ( exp. ) ± 3 ( theo. ) GeV / c 2 , where the first uncertainty is experimental and the second uncertainty is theoretical. This value is compatible with the limit from direct Higgs boson search at LEP.

Mass Bounds on a Very Light Neutralino

Within the Minimal Supersymmetric Standard Model (MSSM) we systematically investigate the bounds on the mass of the lightest neutralino. We allow for non-universal gaugino masses and thus even consider massless neutralinos, while assuming in general that R-parity is conserved. Our main focus is on laboratory constraints. We consider collider data, precision observables, and also rare meson decays to very light neutralinos. We then discuss the astrophysical and cosmological implications. We find that a massless neutralino is allowed by all existing experimental data and astrophysical and cosmological observations.

Z pole observables in the MSSM

We present the currently most accurate prediction of Z pole observables such as sin^2 theta_eff, Gamma_Z, R_b, R_l, and sigma^0_had in the Minimal Supersymmetric Standard Model (MSSM). We take into account the complete one-loop results including the full complex phase dependence, all available MSSM two-loop corrections as well as the full SM results. We furthermore include higher-order corrections in the MSSM Higgs boson sector, entering via virtual Higgs boson contributions. For Gamma(Z -> neutralino{1} neutralino{1}) we present a full one-loop calculation. We analyse the impact of the different sectors of the MSSM with particular emphasis on the effects of the complex phases. The predictions for the Z boson observables and M_W are compared with the current experimental values. Furthermore we provide an estimate of the remaining higher-order uncertainties in the prediction of sin^2 theta_eff.

Precise prediction for M(W) in the MSSM

We present the currently most accurate evaluation of the W boson mass, MW, in the Minimal Supersymmetric Standard Model (MSSM). The full complex phase dependence at the one-loop level, all available MSSM two-loop corrections as well as the full Standard Model result have been included. We analyse the impact of the different sectors of the MSSM at the one-loop level with a particular emphasis on the effect of the complex phases. We discuss the prediction for MW based on all known higher-order contributions in representative MSSM scenarios. Furthermore we obtain an estimate of the remaining theoretical uncertainty from unknown higher-order corrections.

Precise prediction for MW in the MSSM

We present the currently most accurate evaluation of the W boson mass, MW, in the Minimal Supersymmetric Standard Model (MSSM). The full complex phase dependence at the one-loop level, all available MSSM two-loop corrections as well as the full Standard Model result have been included. We analyse the impact of the different sectors of the MSSM at the one-loop level with a particular emphasis on the effect of the complex phases. We discuss the prediction for MW based on all known higher-order contributions in representative MSSM scenarios. Furthermore we obtain an estimate of the remaining theoretical uncertainty from unknown higher-order corrections.

The Dark Side of mSUGRA

We study the μ μ>0 in global fits is calculated with Markov Chain Monte Carlo methods and bridge sampling. The fits include state-of-the-art two-loop MSSM contributions to the electroweak observables MW and sin 2θwl, as well as the anomalous magnetic moment of the muon (g−2)μ, the relic density of dark matter and other relevant indirect observables. μ 0) = 0.07−0.16.

Global fits of the large volume string scenario to WMAP5 and other indirect constraints using Markov chain Monte Carlo

We present global fits to the Large Volume Scenario (LVS) of string models using current indirect data. We use WMAP5 constraints on dark matter relic density, b-physics and electroweak observables as well as direct search constraints. Such data can be adequately fit by LVS, with the best-fit point for 0

Testing the minimal supersymmetric standard model with the mass of the W boson

>μ>0 having χ2 = 13.6 for 8 degrees of freedom. The resulting constraints on parameter space are robust in that they do not depend much upon the prior, or upon whether one uses Bayesian or frequentist interpretations of the data. Sparticle masses are constrained to be well below the 1 TeV level, predicting early SUSY discovery at the LHC. We devise a method of quantifying which are the most important constraints. We find that the LEP2 Higgs mass constraint, the relic density of dark matter and the anomalous magnetic moment of the muon affect the fits to the strongest degree.

Precision Observables in the MSSM: W mass and the muon magnetic moment

We review the currently most accurate evaluation of the W boson mass, MW , in the Minimal Supersymmetric Standard Model (MSSM). It consists of a full one-loop calculation, including the complex phase dependence, all available MSSM two-loop corrections as well as the full Standard Model result. We analyse the impact of th e phases in the scalar quark sector onMW and compare the prediction for MW based on all known higher-order contributions with the experimental results. talk given by S. Heinemeyer at the LCWS06, 9-13 March 2006, Bangalore, India email: Sven.Heinemeyer@cern.ch email: hollik@mppmu.mpg.de email: Dominik.Stockinger@durham.ac.uk email: Arne.Weber@mppmu.mpg.de email: Georg.Weiglein@durham.ac.uk PRAMANA c

Precise prediction forMWin the MSSM

The precision observables MW and g − 2 of the muon are discussed in the framework of the MSSM. Recent progress in the evaluation of the theoretical predictions is described, and the MSSM predictions are compared with the SM predictions and the experimental values.