Download or read book Search for New Particles Decaying to Dijets B bar B and T bar T at CDF written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present three searches for new particles at CDF. First, using 70 pb[sup[minus]1] of data we search the dijet mass spectrum for resonances. There is an upward fluctuation near 550 GeV/c[sup 2] (2.6[sigma]) with an angular distribution that is adequately described by either QCD alone or QCD plus 5% signal. There is insufficient evidence to claim a signal, but we set the most stringent mass limits on the hadronic decays of axigluons, excited quarks, technirhos, W[prime], Z[prime], and E6 diquarks. Second, using 19 pb[sup[minus]1] of data we search the b-tagged dijet mass spectrum for b[bar b] resonances. Again, an upward fluctuation near 600 GeV/c[sup 2] (2[sigma]) is not significant enough to claim a signal, so we set the first mass limits on topcolor bosons. Finally, using 67 pb[sup[minus]1] of data we search the top quark sample for t[bar t] resonances like a topcolor Z[prime]. Other than an insignificant shoulder of 6 events on a background of 2.4 in the mass region 475--550 GeV/c[sup 2], there is no evidence for new particle production. Mass limits, currently in progress, should be sensitive to a topcolor Z[prime] near 600 GeV/c[sup 2]. In all three searches there is insufficient evidence to claim new particle production, yet there is an exciting possibility that the upward fluctuations are the first signs of new physics beyond the standard model.

Download or read book Search for New Particles Decaying to Dijets written by and published by . This book was released on 1995 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1996 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for New Particles Decaying to Dijets in Pbar P Collisions at Radicals written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1992 with total page 1232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nuclear Data written by and published by . This book was released on 1997 with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Particle Searches at CDF written by and published by . This book was released on 1995 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the fundamental roles of a general purpose detector exploring, by means of increasing luminosity, higher and higher mass reach, is to search for new particles and exotic phenomena. This is a continuing effort for the CDF collaboration, and will report on several searches using about 20 pb−1 from the 1992/93 run labelled {open_quotes}run 1a{close_quotes} and (approximately)50 of the 90 pb−1 so far from the current {open_quotes}run 1b.{close_quotes} These are mostly preliminary analyses, typically using a total of 70 pb−1. Our limits on SUSY using missing E{sub T} with jets as well as three leptons are discussed elsewhere; results from the D0 collaboration are similar. I will discuss searches for additional vector bosons Z(prime) and W(prime), second generation scalar leptoquarks, as well as a broad search for objects decaying into jet pairs, including b-tagged jet pairs. I will also describe two events which do not fit in comfortably with either the standard model or a phenomenologically motivated search.

Download or read book Die Republikein written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Top Decay to Lepton Jets written by and published by . This book was released on 1995 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top search in the lepton plus jets channel with the Collider Detector at Fermilab (CDF) is presented. The analysis uses a 67 pb−1 data sample of p{bar p} collisions at √s = 1.8 TeV. Soft lepton tagging (SLT) and secondary vertex tagging (SVX) of b jets are used to reduce backgrounds. A significant excess of events over expected backgrounds is seen, and together with the excess of observed events in the dilepton (DIL) channel, firmly establish the existence of the top quark. Combining all channels, the t{bar t} production cross section is measured to be [sigma] {sub t{bar t}} = 7.6{sub -2.0}{sup +2.4} pb. The Branching of top to Wb is measured to be Br(t → Wb) = 0.87{sub -0.30}{sup +0.13}(stat) {sub -0.11}{sup +0.13}(syst).

Download or read book Search for New Particles Decaying to Two jets with the D Detector written by Christina Lee Hebert and published by . This book was released on 2003 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Search for New Particles Decaying Into Tt Pairs written by Josh A. Cassada and published by . This book was released on 1999 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for a Neutral Long lived Particle Decaying to B jets written by Chad Jeremy Johnson and published by . This book was released on 2009 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rare B Decays and Time Dependent Mixing at CDF written by and published by . This book was released on 1995 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report recent results on rare B decays searches -- specifically, the decay modes B° →??−, B° →?+?−K{sup 0*}, and B{sup {plus_minus}} →?+?−K{sup {plus_minus}} -- from the CDF collaboration using data from the 1992--1993 run of the Tevatron collider. In addition, we present the first CDF measurement of time dependent B° - {bar B}° mixing.

Download or read book High Energy Physics Index written by and published by . This book was released on 1990 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book B physics written by Vyacheslav Krutelyov and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results and prospects for searches for rare B and D meson decays with final state dimuons, including B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -}, B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -}, and D{sup 0} {yields} {mu}{sup +}{mu}{sup -}. B0 Upper limits on the branching fractions are compared to previous CDF measurements, recent results from the B factories and theoretical expectations. We also report on new measurements of production and decay properties of the X(3872) particle, discovered in 2003 by the Belle Collaboration. New results on the measurement of the relative branching fraction for the Cabibbo suppressed decay B{sup +} {yields} J/{psi}{pi}{sup +} {Beta}(B{sup +} {yields} J/{psi}{pi}{sup +})/{Beta}(B{sup +} {yields} J/{psi}K{sup +}) are presented too. The presented results are based on the analyses of 70 to 220 pb{sup -1} of data collected by the CDF II detector in p{bar p} collisions at {radical}s = 1.96 GeV at Fermilab Tevatron.

Download or read book Search for B0 Decays to Invisible Final States and to Nu Nubar Gamma written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We establish upper limits on branching fractions for B[sup 0] decays to final states where the decay products are purely invisible (i.e., no observable final state particles) and for B[sup 0] decays to [nu][bar [nu]][gamma]. Within the Standard Model, these decays have branching fractions that are below current experimental sensitivity, but various models of physics beyond the Standard Model predict significant contributions from these channels. Using 88.5 million B[bar B] pairs collected at the [Upsilon](4S) resonance by the BABAR experiment at the PEP-II e[sup +]e[sup -] storage ring at the Stanford Linear Accelerator Center, we establish upper limits at the 90% confidence level of 22 x 10[sup -5] for the branching fraction of B[sup 0] [yields] invisible and 4.7 x 10[sup -5] for the branching fraction of B[sup 0] [yields] [nu][bar [nu]][gamma].