Measurements of Diffractive Processes at CDF

We review the results of measurements on hard diffractive processes performed by the CDF Collaboration and report preliminary CDF results on two soft diffractive processes with a leading antiproton and a rapidity gap in addition to that associated with the antiproton. All results have been obtained from data collected in Run I of the Fermilab Tevatron $\bar pp$ collider.Comment: 7 pages, Presented at 14$^{th}$ Topical Conference on Hadron Collider Physics, HCP-2002, Karlsruhe, Germany, 29 Sep - 4 Oct 200

Experimental review of diffractive phenomena

A review is given of the measurements of the hard diffractive interactions in recent years from two high-energy colliders, the HERA $ep$ collider and the Tevatron $p\bar{p}$ collider. The structure of the diffractive exchange in terms of partons, the factorisation properties and the ratio of diffractive to non-diffractive cross sections are discussed.Comment: Contribution to the proceedings of BARYONS 2004. LaTeX 10 page

Energy Level Diagrams for Black Hole Orbits

A spinning black hole with a much smaller black hole companion forms a fundamental gravitational system, like a colossal classical analog to an atom. In an appealing if imperfect analogy to atomic physics, this gravitational atom can be understood through a discrete spectrum of periodic orbits. Exploiting a correspondence between the set of periodic orbits and the set of rational numbers, we are able to construct periodic tables of orbits and energy level diagrams of the accessible states around black holes. We also present a closed form expression for the rational q, thereby quantifying zoom-whirl behavior in terms of spin, energy, and angular momentum. The black hole atom is not just a theoretical construct, but corresponds to extant astrophysical systems detectable by future gravitational wave observatories.Comment: 8 page

Diffractive Higgs boson production at Tevatron and LHC: an experimental review

We discuss the different models of central diffractive production of the Higgs boson at the Tevatron and the LHC. We also describe how the models can be tested using diffractive production data being taken at the Tevatron. We finally discuss the advantages of using diffractive events to reconstruct the mass of the Higgs boson especially at the LHC.Comment: short review to be published in Mod. Phys. Let

Triangular mass matrices for quarks and leptons

We assume that all quark and lepton $3 \times 3$ mass matrices which appear in the standard model lagrangian (after spontaneous symmetry breaking) with neutrinos treated as Dirac patricles have the triangular form. Such matrices have not only less non-zero elements (three of them are equal to zero) but also lead to very asymmetrical decomposition into one diagonal and two unitary matrices for quarks and leptons. We also assume that unitary matrices which transform flavor into definite mass states for right handed components (weakly non-interacting) in the same weak isodoublet are equal. Using all available experimental data on quark and lepton masses and mixing angles, treating in the universal way quarks and leptons, we determine the triangular mass matrices for up and down type quarks, neutrinos and charged leptons and as a consequence mixing matrices for left-handed and right handed components. As the result of the fit we get predictions for the neutrino masses including smallest neutrino mass. The calculations without CP violation and with inclusion of this effect in quark sector are also presented.Comment: 12 pages, no figure

Diffraction in hadron-hadron interactions

Results on soft and hard diffraction in $pp$ and $\bar pp$ collisions are reviewed with emphasis on factorization and scaling properties of differential cross sections. While conventional factorization breaks down at high energies, a scaling behavior emerges, which leads to a universal description of diffractive processes in terms of a (re)normalized rapidity gap probability distribution.Comment: 12 pages, Late

W Boson Cross Section and Decay Properties at the Tevatron

We present the first measurements of sigma(p\bar{p} -> W -> l nu) and sigma(p\bar{p} -> Z -> l l) at sqrt{s} = 1.96 TeV, along with new measurements of W angular-decay distributions in p\bar{p} collisions at sqrt{s} = 1.8 TeV.Comment: Submitted to ICHEP 2002 proceeding

Design and Expected Performance of the BTeV RICH

The BTeV experiment is a b-physics experiment designed to conduct precision tests of the CKM description of CP violation and study rare processes involving bottom and charm hadrons. The experiment will be located in the C0 interaction region at the Fermilab Tevatron, and is intended to begin data-taking around 2007-2008. One of the most important elements of the BTeV spectrometer is the ring-imaging Cerenkov detector (RICH) which is used for particle identification. In this article we describe the BTeV RICH and present its expected performance.Comment: 5 pages, 5 figures. Proceedings of the RICH2002 Conference, Pylos, Greece, June 5-10, 200

Top squark mass: current limits revisited and new limits from Tevatron Run-I

Analyzing the $\ell +n$-jets+ \met (where $n \ge 2$), data from Run-I of the Tevatron using the Bayesian technique, we obtain model independent limits on the product \br(\lstop\ra be^{+}\nu_e \lspone) \times \br(\lstop^{*}\ra \bar{b}q\bar{q^{\prime}}\lspone) for different values of the lighter top squark(\lstop) mass and the lightest supersymmetric particle(\lspone) mass. The SUSY signals have been simulated by interfacing the 4-body decay of \lstop at the parton level with the event generator PYTHIA. These limits have been translated into exclusion plots in the \mlstop-\mlspone plane, which also turn out to be fairly model independent for fixed values of the BR of the competing loop decay mode \lstop\ra c \lspone. Assuming the loop decay BR to be negligible and using the leading order cross section for \lstoplstop pair production, we obtain conservatively \mlstop \ge 77.0 (74.5) GeV for \mlspone=5(15) GeV, while for \br(\lstop\ra c \lspone)=20%, the corresponding limits are \mlstop \ge 68.0 (65.0) GeV. Using the larger next to leading order cross-section stronger limits are obtained. For example, if \br(\lstop\ra c \lspone)=20%, \mlstop \ge 73.0 (72.7) GeV for \mlspone=5(15) GeV. Our limits nicely complement the ALEPH bounds which get weaker for low \mlspone.Comment: 11 pages, 5 figures, few comments adde

Top Quark Mass Measurements at CDF

Recent measurements of the mass of the top quark are presented using 162 pb-1 of data of ppbar collisions at sqrt(s)=1.96 TeV collected by the CDF detector at the Tevatron collider during Run II. The analyses focus on the semi-leptonic decay mode with one or two identified bottom quarks. The Template Method reconstructs the invariant mass of the top quark in each event. The Multivariate Template Method enhances this approach by adding information on the event topology. The Dynamical Likelihood Method discriminates between possible mass values using top quark decay observables and attempts to use the maximum amount of information on top quarks provided by the Standard Model. All three methods produce similar results. The Dynamical Likelihood Method yields a top quark mass of 177.8+-4.5/5.0(stat)+-6.2(sys)GeV/c^2.Comment: 4 pages, 3 figures. Referee's comments included. To appear in the proceedings of the 6th International Conference on Hyperons, Charm and Beauty Hadrons, June 27 - July 03, 2004, Chicago, IL, US