Measuring the mass of the W at the LHC

We explore the ability of the Large Hadron Collider to measure the mass of the W boson. We believe that a precision better than ~ 15 MeV could be attained, based on a year of operation at low luminosity (10^(33)cm^(-2)s^(-1)). If this is true, this measurement will be the world's best determination of the W mass. We feel this interesting opportunity warrants investigation in more detail

Summary of the Very Large Hadron Collider Physics and Detector Workshop

One of the options for an accelerator beyond the LHC is a hadron collider with higher energy. Work is going on to explore accelerator technologies that would make such a machine feasible. This workshop concentrated on the physics and detector issues associated with a hadron collider with an energy in the center of mass of the order of 100 to 200 TeV

Optimal use of Information for Measuring MtM_t in Lepton+jets ttˉt\bar{t} Events

We present a novel approach that is being developed at DZero for extracting information from data through a direct comparison of all measured variables in an event with a matrix element that describes the entire production process. The method is exemplified in the extraction of the mass of the top quark in top-antitop events in the lepton+jets final state. Monte Carlo studies suggest that an improvement of about a factor of two in statistical uncertainty on the mass of the top quark can be achieved relative to previously published work for the same channel. Preliminary results from the re-analysis provide a reduction in the statistical uncertainty of almost a factor of 1.6, corresponding to an effective factor of 2.4 increase in the size of the data sample.Comment: presented at HCP200

Single Top Quark Production as a Probe for Anomalous Moments at Hadron Colliders

Single production of top quarks at hadron colliders via $gW$ fusion is examined as a probe of possible anomalous chromomagnetic and/or chromoelectric moment type couplings between the top and gluons. We find that this channel is far less sensitive to the existence of anomalous couplings of this kind than is the usual production of top pairs by $gg$ or $q\bar q$ fusion. This result is found to hold at both the Tevatron as well as the LHC although somewhat greater sensitivity for anomalous couplings in this channel is found at the higher energy machine.Comment: New discussion and 10 new figures added. uuencoded postscript fil

Weakly-Coupled Higgs Bosons and Precision Electroweak Physics

We examine the prospects for discovering and elucidating the weakly-coupled Higgs sector at future collider experiments. The Higgs search consists of three phases: (i) discovery of a Higgs candidate, (ii) verification of the Higgs interpretation of the signal, and (iii) precision measurements of Higgs sector properties. The discovery of one Higgs boson with Standard Model properties is not sufficient to expose the underlying structure of the electroweak symmetry breaking dynamics. It is critical to search for evidence for a non-minimal Higgs sector and/or new physics associated with electroweak symmetry breaking dynamics. An improvement in precision electroweak data at future colliders can play a useful role in confirming the theoretical interpretation of the Higgs search results

Physics Beyond the Standard Model

I briefly summarize the prospects for extending our understanding of physics beyond the standard model within the next five years.Comment: 9 pages, 2 figures, LaTeX. Presented at the 1999 UK Phenomenology Workshop, Durham, September 1999. To be published in Journal of Physics

Multigene analyses resolve early diverging lineages in the Rhodymeniophycidae (Florideophyceae, Rhodophyta).

Multigene phylogenetic analyses were directed at resolving the earliest divergences in the red algal subclass Rhodymeniophycidae. The inclusion of key taxa (new to science and/or previously lacking molecular data), additional sequence data (SSU, LSU, EF2, rbcL, COI-5P), and phylogenetic analyses removing the most variable sites (site stripping) have provided resolution for the first time at these deep nodes. The earliest diverging lineage within the subclass was the enigmatic Catenellopsis oligarthra from New Zealand (Catenellopsidaceae), which is here placed in the Catenellopsidales ord. nov. In our analyses Atractophora hypnoides was not allied with the other included Bonnemaisoniales, but resolved as sister to the Peyssonneliales, and is here assigned to Atractophoraceae fam. nov. in the Atractophorales ord. nov. Inclusion of Acrothesaurum gemellifilum gen. et sp. nov. from Tasmania has greatly improved our understanding of the Acrosymphytales, to which we assign three families, the Acrosymphytaceae, Acrothesauraceae fam. nov. and Schimmelmanniaceae fam. nov. This article is protected by copyright. All rights reserved