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 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 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].

Download or read book Search for New Particles in CDF written by and published by . This book was released on 1991 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Preliminary results on searches for new particles beyond the Standard Model are presented. The data were taken by the CDF collaboration at the Fermilab {bar p}p collider at a center of mass energy of 1.8 TeV. Limits on the masses of the gluino and squark in a minimal supersymmetric theory are given. The 90% confidence level asymptotic lower mass limits on each are 150 GeV/c2. A special data run was taken to search for the diffractively produced sextet quark state?6. An?6 with a mass larger than 20 GeV/c2 is excluded at the 95% confidence level. Limits are also set on the pair-production of massive stable charged particles. Unit-charged particles belonging to spin 1⁄2 color triplets with masses between 50 and 139 GeV/c2 are ruled out at the 95% confidence level as are charge 2/3 particles with masses between 50 and 116 GeV/c2 and charge 4/3 particles with masses between 50 and 140 GeV/c2. 5 refs., 3 figs.

Download or read book Search for Eta B at CDF written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The[eta][sub b] (1S) is the J[sup PC]= 0[sup[-+]] b[bar b] ground state, and has not yet been experimentally observed. Theorists have recently suggested that it could be observed at the Fermilab Tevatron through its decay to J/[psi]J/[psi], if not in the 1992-96 (''Run 1'') dataset, then in Run 2. This article describes a search for this particle at CDF in Run 1 using this decay channel. A small cluster is seen, with 7 events where 1.8 events are expected from background. The statistical significance is estimated to be 2.2[sigma], and an upper limit is set on the product of cross section and branching fractions.