Search for New Physics at CDF

We present the current status of the search for new physics at CDF, using integrated luminosity up to 3.2 fb-1. We cover searches for supersymmetry, extra dimensions, new heavy bosons, and generic dilepton resonances.Comment: Contribution to the proceedings of Lake Louise Winter Institute: Fundamental Interactions (LLWI 2009), Lake Louise, Alberta, Canada, February 16-21, 200

Search for trilepton SUSY signal at CDF

The chargino-neutralino production with subsequent leptonic decays is one of the most promising supersymmetry (SUSY) signatures at the Tevatron proton-antiproton collider. We present the most recent results on the search for the three-lepton and missing-transverse-energy SUSY signature using 3.2 fb-1 of data collected with the CDF II detector. The results are interpreted within the minimal supergravity (mSUGRA) scenario.Comment: Proceedings of the 17th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY 09), Boston MA, USA, June 5-10, 2009. To be published by the American Institute of Physic

Search for RS-gravitons at CDF

We present a search for Randall-Sundrum (RS) gravitons decaying to diphotons or dielectrons or dimuons, performed with the CDF II detector and using up to 5.7 fb-1 of integrated luminosity. The respective mass spectra are consistent with the ones expected by the standard model. For the RS-model parameter k/M_Pl=0.1, RS-gravitons with mass less than 1111 GeV/c^2 are excluded at 95% CL.Comment: XIX International Workshop on Deep Inelastic Scattering and related subjects -- DIS11, Newport News, VA, USA Apr. 11-15, 2011 [4 pages, 4 figures

Heavy Flavor Production in CDF II Detector

For data collected with the CDF Run II detector, measurements of the charm and bottom production cross-sections are presented. The results are based both on large samples of fully reconstructed hadron decay products of charm and bottom made available by the tracking triggers and on a calorimeter jet triggered sample tagged by the presence of a secondary vertex. The experimental data are compared with theoretical predictions from recent next-to-leading order (NLO) QCD calculations.Comment: 5 pages, 3 figures; a write up of the talk given on behalf of the CDF Collaboration at the XVII Particles and Nuclei International Conference, PANIC 05, October 24-28, 2005, Santa Fe, New Mexico, U.S.

Stirring the Embers: High Sensitivity VLBI Observations of GRB030329

We present high sensitivity Very Long Baseline Interferometry (VLBI) observations 806 days after the gamma-ray burst of 2003 March 29 (GRB030329). The angular diameter of the radio afterglow is measured to be 0.347 +- 0.09 mas, corresponding to 0.99 +- 0.26 pc at the redshift of GRB030329 (z = 0.1685). The evolution of the image size favors a uniform external density over an R^-2 wind-like density profile (at distances of R >~10^18 cm from the source), although the latter cannot be ruled out yet. The current apparent expansion velocity of the image size is only mildly relativistic, suggesting a non-relativistic transition time of t_NR ~ 1 yr. A rebrightening, or at least a significant flattening in the flux decay, is expected within the next several years as the counter-jet becomes visible (this has not yet been observed). An upper limit of <1.9c is set on the proper motion of the flux centroid.Comment: 16 pages, 5 figures, accepted for publication in Astrophysical Journa

Diversity Of Short Gamma-Ray Burst Afterglows From Compact Binary Mergers Hosting Pulsars

Short gamma-ray bursts (sGRBs) are widely believed to result from the mergers of compact binaries. This model predicts an afterglow that bears the characteristic signatures of a constant, low density medium, including a smooth prompt-afterglow transition, and a simple temporal evolution. However, these expectations are in conflict with observations for a non-negligible fraction of sGRB afterglows. In particular, the onset of the afterglow phase for some of these events appears to be delayed and, in addition, a few of them exhibit late- time rapid fading in their lightcurves. We show that these peculiar observations can be explained independently of ongoing central engine activity if some sGRB progenitors are compact binaries hosting at least one pulsar. The Poynting flux emanating from the pulsar companion can excavate a bow-shock cavity surround- ing the binary. If this cavity is larger than the shock deceleration length scale in the undisturbed interstellar medium, then the onset of the afterglow will be delayed. Should the deceleration occur entirely within the swept-up thin shell, a rapid fade in the lightcurve will ensue. We identify two types of pulsar that can achieve the conditions necessary for altering the afterglow: low field, long lived pulsars, and high field pulsars. We find that a sizable fraction (~20-50%) of low field pulsars are likely to reside in neutron star binaries based on observations, while their high field counterparts are not. Hydrodynamical calculations motivated by this model are shown to be in good agreement with observations of sGRB afterglow lightcurves.Comment: Accepted to ApjL. Direct comparison to observed X-Ray afterglows now included. 5 Figure