119283621
Results from 730 kg days of the CRESST-II Dark Matter search
The CRESST-II cryogenic Dark Matter search, aiming at detection of WIMPs via elastic scattering off nuclei in CaWO4 crystals, completed 730 kg days of data taking in 2011. We present the data collected with eight detector modules, each with a two-channel readout; one for a phonon signal and the other for coincidently produced scintillation light. The former provides a precise measure of the energy deposited by an interaction, and the ratio of scintillation light to deposited energy can be used to discriminate different types of interacting particles and thus to distinguish possible signal events from the dominant backgrounds.Sixty-seven events are found in the acceptance region where a WIMP signal in the form of low energy nuclear recoils would be expected. We estimate background contributions to this observation from four sources: (1) “leakage” from the e/γ-band (2) “leakage” from the α-particle band (3) neutrons and (4) 206Pb recoils from 210Po decay. Using a maximum likelihood analysis, we find, at a statistical significance of more than 4σ, that these sources alone are not sufficient to explain the data. The addition of a signal due to scattering of relatively light WIMPs could account for this discrepancy, and we determine the associated WIMP parameters.
119176850
The CRESST II Dark Matter Search
Direct Dark Matter detection with cryodetectors is briefly discussed, with particular mention of the possibility of the identification of the recoil nucleus. Preliminary results from the CRESST II Dark Matter search, with 730 kg-days of data, are presented. Major backgrounds and methods of identifying and dealing with them are indicated.
209431040
Dark Matter Search with CRESST-II
R. Strauss, G. Angloher, M. Bauer, I. Bavykina, A. Bento, C. Bucci, C. Ciemniak, G. Deuter, F. von Feilitzsch, D. Hauff, C. Isaila, J. Jochum, M. Kiefer, M. Kimmerle, J.-C. Lanfranchi, F. Petricca, S. Pfister, W. Potzel, F. Pröbst , F. Reindl , S. Roth, K. Rottler, C. Sailer, K. Schäffner, J. Schmaler, S. Scholl, W. Seidel, M. von Sivers, L. Stodolsky , C. Strandhagen, A. Tanzke, I. Usherov, S. Wawoczny, M. Willers, A. Zöller Physik-Department E15, Technische Universität München, D-85747 Garching, Germany Max-Planck-Institut für Physik, D-80805 München, Germany Eberhard-Karls-Universität Tübingen, D-72076 Tübingen, Germany Laboratori Nazionali del Gran Sasso, INFN, I-67010 Assergi, Italy Departamento de Fisica, Universidade de Coimbra, P3004 516 Coimbra, Portugal
38251987
Solution to the flavor problem of warped extra-dimension models.
A minimal solution to the flavor problem of warped extra-dimension models, i.e., the excessive mixed-chirality contribution to CP violation in K-K ¯ mixing arising from Kaluza-Klein (KK) gluon exchange, is proposed. Extending the strong-interaction gauge group in the bulk by an additional SU(3), and breaking this symmetry to QCD via boundary conditions, the constraints arising from the ε(K) parameter are significantly relaxed. As a result, KK scales M(KK)~2 TeV are consistent with all flavor observables without significant fine-tuning. The model predicts an extended Higgs sector featuring massive color-octet scalars and a tower of KK pseudoaxial gluon resonances, whose existence is not in conflict with recent LHC dijet bounds.
18094742
Exclusive semileptonic decays of heavy mesons
AbstractExclusive semileptonic decays of heavy mesons provide interesting information on systems consisting of quarks of unequal mass. We express the formfactors of the hadronic current in terms of relativistic bound state wave functions for which we take the solutions of a relativistic harmonic oscillator potential. The wave function overlap is determined by the quark mass dependent longitudinal momentum distribution and differs from results based on non relativistic wave functions. The semileptonic widths and lepton spectra are calculated using in addition nearest pole dominance for the momentum transfer dependence of the formfactors. We compare our results with recent experimental data. The formfactor calculation also allows an estimate of special nonleptonic transitions. From the CLEO results on
$$\bar B^0 \to \pi ^ + \pi ^ -$$
 and
$$\bar B^0 \to D^{* + } + \pi ^ -$$
 we find for the corresponding Kobayashi-Maskawa matrix element ratio the limit |Vub/Vcb|≲0.3.
107502491
Bipolar monolithic preamplifiers for SSC silicon calorimetry
This paper describes preamplifiers designed specifically to address the requirements of silicon calorimetry for the Superconducting Super Collider (SSC). Eight different preamplifiers designed for detector capacitances ranging from 20 pF to 500 pF and operating temperatures from 25{degree}C to {minus}20{degree}C are discussed. The preamplifiers were fabricated with two different high-frequency processes (one with the VTC, Inc. VJ900 process, seven with the Harris Semiconductor VHF Process). The different topologies and their features are discussed in addition to the design methodologies employed. The results for noise, power consumption, speed, and radiation damage effects as well as data for post-damage annealing are presented for the VTC process preamplifier. Simulations for the VHF Process circuits are presented. This work was funded through SSC Generic Detector funding, SSC Detector Subsystem funding, and the Oak Ridge National Laboratory (ORNL) Detector Center.
15486552
Comments on the links between SU(3) modular invariants, simple factors in the Jacobian of Fermat curves, and rational triangular billiards
We examine the proposal made recently that the su(3) modular invariant partition functions could be related to the geometry of the complex Fermat curves. Although a number of coincidences and similarities emerge between them and certain algebraic curves related to triangular billiards, their meaning remains obscure. In an attempt to go beyond the su(3) case, we show that any rational conformal field theory determines canonically a Riemann surface. Comment: 56 pages, 4 eps figures, LaTeX, uses epsf
121043272
Centre and representations of small quantum superalgebras at roots of unity
When the deformation parameter is a root of unity, the centre of a quantum group can be described by a set of generators and non trivial relations. In the case ofUq(sl(N)), these relations simply derive from the expressions of the deformed Casimir operators. In the case ofUq(osp(1|2)), the relation is simple if we use an operator which anticommutes with the fermionic generators and whose square is the quadratic Casimir. This operator also simplifies the classification of finite dimensional irreducible representations. In the case ofUq(sl(1|2)), the relations derive from the (infinite set of) standard Casimir operators.