Dark matter and collider phenomenology of universal extra dimensions

Stable massive particles at colliders

We report new results from the Cryogenic Dark Matter Search (CDMS II) at the Soudan Underground Laboratory Two towers, each consisting of six detectors, were operated for 745 live days, giving spectrum-weighted exposures of 34 kg-d for germanium and 12 kg-d for silicon targets after cuts, averaged over recoil energies 10-100 keV for a WIMP mass of 60GeV/c{sup 2} A blind analysis was conducted, incorporating improved techniques for rejecting surface events No WIMP signal exceeding expected backgrounds was observed When combined with our previous results from Soudan, the 90% CL upper limit on the spin-independent WIMP-nucleon cross section is 16 x 10{sup -43} cm{sup 2} from Ge, and 3 x 10{sup -42} cm{sup 2} from Si, for a WIMP mass of 60GeV/c{sup 2} The combined limit from Ge (Si) is a factor of 25 (10) lower than our previous results, and constrains predictions of supersymmetric models

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Limits on spin-independent interactions of weakly interacting massive particles with nucleons from the two-tower run of the cryogenic dark matter search.

We review the current status of liquid noble gas radiation detectors with energy threshold in the keV range, which are of interest for direct dark matter searches, measurement of coherent neutrino scattering and other low energy particle physics experiments. Emphasis is given to the operation principles and the most important instrumentation aspects of these detectors, principally of those operated in the double-phase mode. Recent technological advances and relevant developments in photon detection and charge readout are discussed in the context of their applicability to those experiments.

Liquid noble gas detectors for low energy particle physics

We perform a comprehensive exploration of the Constrained MSSM parameter space employing a Markov Chain Monte Carlo technique and a Bayesian analysis. We compute superpartner masses and other collider observables, as well as a cold dark matter abundance, and compare them with experimental data. We include uncertainties arising from theoretical approximations as well as from residual experimental errors of relevant Standard Model parameters. We delineate probability distributions of the CMSSM parameters, the collider and cosmological observables as well as a dark matter direct detection cross section. The 68% probability intervals of the CMSSM parameters are: 0.52TeV < m1/2 < 1.26TeV, m0 < 2.10TeV, ?0.34TeV < A0 < 2.41TeV and 38.5 < tan ? < 54.6. Generally, large fractions of high probability ranges of the superpartner masses will be probed at the LHC. For example, we find that the probability of m < 2.7TeV is 78%, of mR < 2.5TeV is 85% and of m?1? < 0.8TeV is 65%. As regards the other observables, for example at 68% probability we find 3.5 ? 10?9 < BR(Bs??+??) < 1.7 ? 10?8, 1.9 ? 10?10 < ?a?SUSY < 9.9 ? 10?10 and 1 ? 10?10?pb < ?SIp < 1 ? 10?8?pb for direct WIMP detection. We highlight a complementarity between LHC and WIMP dark matter searches in exploring the CMSSM parameter space. We further expose a number of correlations among the observables, in particular between BR(Bs??+??) and BR(?Xs?) or ?SIp. Once SUSY is discovered, this and other correlations may prove helpful in distinguishing the CMSSM from other supersymmetric models. We investigate the robustness of our results in terms of the assumed ranges of CMSSM parameters and the effect of the (g?2)? anomaly which shows some tension with the other observables. We find that the results for m0, and the observables which strongly depend on it, are sensitive to our assumptions, while our conclusions for the other variables are robust.

https://iopscience.iop.org/article/10.1088/1126-6708/2006/05/002/pdf

M. Robinson

Papers

First limits on nuclear recoil events from the ZEPLIN I galactic dark matter detector