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Radiative corrections to heavy Higgs physics

Description: The one-loop correction to the width of a 1 TeV Higgs boson is rather modest; it increases the tree width by only 15%. This is surprising in light of the fact that the particle is strongly coupled to itself and to longitudinal gauge bosons. We argue that this may be understood in terms of an effective energy-dependent coupling which is strong for s > m/sub H/S but weak for s < m/sub H/S. 8 refs., 1 fig.
Date: October 1, 1988
Creator: Willenbrock, S.
Partner: UNT Libraries Government Documents Department

Transverse spin observables in chromodynamics

Description: Quantum Chromodynamics confronts a harsh series of tests in the attempt to formulate a comprehensive approach to the calculation of transverse spin observables. The basic obstacles to understanding transverse spin can be illustrated by considering the transverse structure function g{sub T}(x, Q{sup 2}) = g{sub 1}(x, Q{sup 2}) + g{sub 2}(x, Q{sup 2}), extracted from deep-inelastic scattering using a polarized lepton and a polarized proton. The inadequacy of the transverse-spin basis for quarks and gluons found there suggests a new approach to the problems of single-spin observables in large-transverse-momentum processes. This approach, presented earlier for single spin production asymmetries, is discussed here. It is shown that the mechanism can also lead to baryon polarization effects at large P{sub T}. 14 refs.
Date: December 1, 1989
Creator: Sivers, D.
Partner: UNT Libraries Government Documents Department

Structure functions: Their status and implications

Description: I discuss the current status of structure functions. Attention is given to the uncertainties in them and the implications of these uncertainties for experimental predictions. I indicate which experiments are capable of removing these uncertainties. 17 refs., 17 figs., 1 tab.
Date: September 29, 1988
Creator: Hinchliffe, I.
Partner: UNT Libraries Government Documents Department

QCD phenomenology of parton distribution functions at small x

Description: The small x behavior of parton distributions is studied phenomenologically by examining in detail a series of QCD-evolved distribution sets obtained in a new global analysis of deep inelastic scattering and lepton-pair production experiments. The importance of 2-loop evolution is discussed. The main features and results of the global analysis are described. The range of small x behavior consistent with next-to-leading order QCD and current data is delineated. The extrapolated small x behavior is parameterized by effective Q-dependent power- and logarithmic-law parameters. Intriguing features of the evolution of these parameters with Q are presented. Alternative parametrizations based on the analytic solution for small x is also explored. 20 refs., 6 figs., 1 tab.
Date: September 1, 1990
Creator: Tung, Wu-Ki (Illinois Inst. of Tech., Chicago, IL (USA) Fermi National Accelerator Lab., Batavia, IL (USA))
Partner: UNT Libraries Government Documents Department

B factory via conversion of 1 TeV electron beams into 1 TeV photon beams

Description: We derive formulae which describe the interaction of laser beams with electron beams. Specializing to the case of 1 TeV electron beams from the future generation of electron linear accelerators, we calculate the production rate of backscattered 1 TeV photons, and using these photons, we show that it is possible to organize the photoproduction of beauty particles so as to measure 10/sup 9/b/bar b/ pairs per year. This should be adequate to study rare decays and CP violation in B meson decay. 9 refs., 1 fig.
Date: January 1, 1989
Creator: Mtingwa, S.K. & Strikman, M.
Partner: UNT Libraries Government Documents Department

Space-time aspects of hadronic cascading in lepton nucleus scattering

Description: A Monte Carlo model of hadronic cascading in inelastic lepton nucleus scattering is constructed to investigate space-time scenarios consistent with the momentum space description of string models of multiparticle production. The prospects for resolving the ambiguity inherent in the definition of a formation length for composite hadrons are emphasized. 15 refs., 13 figs.
Date: May 1, 1989
Creator: Gyulassy, M. & Pluemer, M.
Partner: UNT Libraries Government Documents Department

Factorization at small x

Description: We show how to modify the Lipatov equation to treat short distance cross sections in the factorization theorem.
Date: January 1, 1990
Creator: Collins, J.C. (Pennsylvania Univ., Philadelphia, PA (USA). Dept. of Physics Argonne National Lab., IL (USA)) & Ellis, R.K. (Fermi National Accelerator Lab., Batavia, IL (USA))
Partner: UNT Libraries Government Documents Department

The role of the axial anomaly in determining spin-dependent parton distributions

Description: It is shown that the forward matrix elements of j{sub 5}{sup {mu}}, the flavor singlet axial vector current, do not measure the helicity carried by quarks and anti-quarks but also include a spin-dependent gluonic component due to the anomaly. Detailed phenomenological and field theoretic reasons are given for the necessity of a gluonic component in the matrix element of j{sub 5}{sup {mu}}. The first higher order corrections to the basic box and triangle graphs are discussed and shown not to modify the conclusions drawn in the leading order calculation. We close with a few comments on the possible phenomenological implications of the anomalous contribution. 25 refs., 6 figs.
Date: July 27, 1989
Creator: Carlitz, R.D.; Collins, J.C. & Mueller, A.H.
Partner: UNT Libraries Government Documents Department

Quarks and gluons in hadrons and nuclei

Description: These lectures discuss the particle-nuclear interface -- a general introduction to the ideas and application of colored quarks in nuclear physics, color, the Pauli principle, and spin flavor correlations -- this lecture shows how the magnetic moments of hadrons relate to the underlying color degree of freedom, and the proton's spin -- a quark model perspective. This lecture reviews recent excitement which has led some to claim that in deep inelastic polarized lepton scattering very little of the spin of a polarized proton is due to its quarks. This lecture discusses the distribution functions of quarks and gluons in nucleons and nuclei, and how knowledge of these is necessary before some quark-gluon plasma searches can be analyzed. 56 refs., 2 figs.
Date: December 1, 1989
Creator: Close, F. E.
Partner: UNT Libraries Government Documents Department

Quarks and gluons in hadrons and nuclei

Description: These lectures discuss the particle-nuclear interface -- a general introduction to the ideas and application of colored quarks in nuclear physics, color, the Pauli principle, and spin flavor correlations -- this lecture shows how the magnetic moments of hadrons relate to the underlying color degree of freedom, and the proton's spin -- a quark model perspective. This lecture reviews recent excitement which has led some to claim that in deep inelastic polarized lepton scattering very little of the spin of a polarized proton is due to its quarks. 38 refs.
Date: January 1, 1989
Creator: Close, F. E.
Partner: UNT Libraries Government Documents Department

The multistring model VENUS for ultrarelativistic heavy ion collisions

Description: The event generator VENUS is based on a multistring model for heavy ion collisions at ultrarelativistic energies. The model is a straightforward extension of a successful model for soft proton-proton scattering, the latter one being consistent with e/sup )plus/)e/sup )minus/) annihilation and deep inelastic lepton scattering. Comparisons of VENUS results with pA and recent AA data alow some statements about intranuclear cascading. 18 refs., 7 figs
Date: February 1, 1988
Creator: Werner, K.
Partner: UNT Libraries Government Documents Department