Recent QCD Results from SLD
Author(s) -
David Müller
Publication year - 1999
Language(s) - English
Resource type - Reports
DOI - 10.2172/15071
Subject(s) - physics , particle physics , quantum chromodynamics , hadron , baryon , nuclear physics , gluon , strangeness , baryon number , rapidity , b meson , hadronization , quark
We present selected results on strong interaction physics from the SLD experiment at the SLAC Linear Collider. We report on several new studies of 3- and 4-jet hadronic Z{sup 0} decays, in which jets are identified as quark, antiquark or gluon. The 3-jet Z{sup 0} --> b anti-bg rate is sensitive to the b-quark mass; prospects for measuring m{sub b} are discussed. The gluon energy spectrum is measured over the full kinematic range, providing an improved test of QCD and limits on anomalous b anti-bg couplings. The parity violation in Z{sup 0} --> b anti-bg decays is consistent with electroweak theory plus QCD. New tests of T- and CP-conservation at the bbg vertex are performed. A new measurement of the rate of gluon splitting into b anti-b pairs yields g{sub b anti-b} = 0.0031 {+-} 0.0007 (stat.){+-} 0.0006 (syst.) (Preliminary). We also present a number of new results on jet fragmentation into identified hadrons. The B hadron energy spectrum is measured over the full kinematic range using a new, inclusive technique, allowing stringent tests of predictions for its shape and a precise measurement of (xB) = 0.714 {+-} 0.005(stat.) {+-} 0.007(syst.) (Preliminary). A detailed study of correlations in rapidity y between pairs of identified pi{sup {+-}}, K{sup {+-}} and p/anti-p confirms that strangeness and baryon number are conserved locally, and shows local charge conservation between meson-baryon and strange-nonstrange pairs. Flavor-dependent long-range correlations are observed for all combinations of these hadron species, yielding new information on leading particle production. The first study of correlations using rapidities signed such that y > 0 corresponds to the quark direction provides additional new insights into fragmentation, including the first direct observation of baryon number ordering along the q anti-q axis
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