New Physics Searches at the Tevatron and the LHC

The Tevatron Run-II started data-taking in spring 2001 and several searches for new particles have been performed. The preliminary 2005 results are concisely reviewed for the experiments CDF and D0. Model-independent and model-dependent limits on Higgs boson and Supersymmetric particle production are set and interpretations are given. Several limits from the LEP era have been extended. The outlook for the Tevatron and the prospects for the ATLAS and CMS experiments at the LHC for selected searches are briefly addressed.Comment: 32 pages, 44 figures, presented at PHENO'05 and Aspen Collider Physics Workshop 200

Heavy Flavour results from Tevatron

The CDF and D0 experiments finalize the analysis of their full statistics collected in the $p \bar p$ collisions at a center-of-mass energy of $\sqrt{s} = 1.96$ TeV at the Fermilab Tevatron collider. This paper presents several new results on the properties of hadrons containing heavy $b$- and $c$-quarks obtained by both collaborations. These results include the search for the rare decays $B^0, B^0_s \to \mu^+ \mu^-$ (CDF), the study of CP asymmetry in $B_s \to J\psi \phi$ decay (CDF, D0), the measurement of the like-sign dimuon charge asymmetry (D0), the measurement of CP asymmetry in $D^0 \to K^+K^-$ and $D^0 \to \pi^+\pi^-$ decays (CDF), and the new measurement of the $B_s \to D_s^{(*)+} D_s^{(*)-}$ branching fraction (CDF). Both experiments still expect to produce more results on the properties of heavy flavours.Comment: Contribution to the XLVIIth Rencontres de Moriond session devoted to Electroweak Interactions and Unified Theorie

Precision Measurement of a Particle Mass at the Linear Collider

Precision measurement of the stop mass at the ILC is done in a method based on cross-sections measurements at two different center-of-mass energies. This allows to minimize both the statistical and systematic errors. In the framework of the MSSM, a light stop, compatible with electro-weak baryogenesis, is studied in its decay into a charm jet and neutralino, the Lightest Supersymmetric Particle(LSP), as a candidate of dark matter. This takes place for a small stop-neutralino mass difference.Comment: 6 pages, 4 figures, 3tables, Conference(Workshop)-LCWS/ILC2007-June,2,200

A Method for the Precision Mass Measurement of the Stop Quark at the International Linear Collider

Many supersymmetric models predict new particles within the reach of the next generation of colliders. For an understanding of the model structure and the mechanism(s) of symmetry breaking, it is important to know the masses of the new particles precisely. In this article the measurement of the mass of the scalar partner of the top quark (stop) at an e+e- collider is studied. A relatively light stop is motivated by attempts to explain electroweak baryogenesis and can play an important role in dark matter relic density. A method is presented which makes use of cross-section measurements near the pair-production threshold as well as at higher center-of-mass energies. It is shown that this method not only increases the statistical precision, but also greatly reduces the systematic uncertainties, which can be important. Numerical results are presented, based on a realistic event simulation, for two signal selection strategies: using conventional selection cuts, and using an Iterative Discriminant Analysis (IDA). Our studies indicate that a precision of \Delta\mstop = 0.42 GeV can be achieved, representing a major improvement over previous studies. While the analysis of stops is particularly challenging due to the possibility of stop hadronization, the general procedure could be applied to the mass measurement of other particles as well. We also comment on the potential of the IDA to discover a stop quark in this scenario, and we revisit the accuracy of the theoretical predictions for the neutralino relic densityComment: 41 pages, 14 figures, in JHEP forma

Long‐Wavelength Sinuosity of Linear Dunes on Earth and Titan and the Effect of Underlying Topography

AbstractOn both Earth and Titan, some linear dunefields are characterized by curvilinear patterning atypical of the regularity and straightness of typical longitudinal dunefields. We use remotely sensed imagery and an automated dune crestline detection algorithm to analyze the controls on spatial patterning. Here it is shown that topography can influence the patterning, as dune alignments bend to deflect downslope under the influence of gravity. The effect is pronounced in a terrestrial dunefield (the Great Sandy desert, Australia) where substantial topography underlies, but is absent where the dunefield is underlain by subdued relief (southwestern Kalahari). This knowledge allows the inference of subtle topographic changes underlying dunefields from dunefield patterning, where other sources of elevation data may be absent. This methodology is explored using the Belet Sand Sea of Titan, where likely areas of topographic change at resolutions finer than those currently available from radar altimetry are inferred.</jats:p

New evidence for super-roughening in crystalline surfaces with disordered substrate

We study the behavior of the Binder cumulant related to long distance correlation functions of the discrete Gaussian model of disordered substrate crystalline surfaces. We exhibit numerical evidence that the non-Gaussian behavior in the low-$T$ region persists on large length scales, in agreement with the broken phase being super-rough.Comment: 10 pages and 4 figures, available at http://chimera.roma1.infn.it/index_papers_complex.html . We have extended the RG discussion and minor changes in the tex