11 research outputs found

    Probing the Weak Boson Sector in γeZe\gamma e\rightarrow Ze

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    We study possible deviations from the standard model in the reaction γeZe\gamma e\rightarrow Ze at a 500 GeV e+ee^+e^- collider. As a photon source we use a laser backscattered photon beam. We investigate the most general γZγ\gamma Z\gamma and γZZ\gamma ZZ vertices including operators up to energy-dimension-six which are Lorentz invariant. These vertices require four extra parameters; two are CP-conserving, h1γh^\gamma_1 and h1Zh^Z_1, and two are CP-violating, h2γh^\gamma_2 and h2Zh^Z_2. We present analytical expressions of the helicity amplitudes for the process γeZe\gamma e\rightarrow Ze for arbitrary values of anomalous couplings. Assuming Standard Model values are actually measured we present the allowed region in the (h1γ,h1Zh^\gamma_1,h^Z_1) plane at the 90\% confidence level. We then show how the angular correlation of the ZZ decay products can be used to extract detailed information on the anomalous (especially CP-violating) γZγ\gamma Z\gamma and γZZ\gamma ZZ couplings.Comment: Latex, 25 pages, 12 figures (not included). One compressed postscript file including all the figures available at ftp://ftp.kek.jp/kek/preprints/TH/TH-420/kekth420.ps.g

    Hadronic ZγZ\gamma Production with QCD Corrections and Leptonic Decays

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    The process ppZγ+X+γ+Xp p \to Z \gamma + X \to \ell^- \ell^+ \gamma + X, where \ell denotes a lepton, is calculated to order αs\alpha_s. Total and differential cross sections, with acceptance cuts imposed on the leptons and photon, are given for the Tevatron and LHC center of mass energies. In general, invariant mass and angular distributions are simply scaled up in magnitude by the QCD radiative corrections, whereas in transverse momentum distributions, the QCD radiative corrections increase with the transverse momentum.Comment: 16 pages + 9 figures, UCD-94-29. A postscript version and 9 postscript figures are available via anonymous ftp to UCDHEP.UCDAVIS.EDU in the directory [.ohnemus.ucd-94-29

    Resolving Ordering Ambiguities in the Collective Quantization by Particle Conjugation Constraints

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    We formulate the particle conjugation operation and its convenient realization as GG--parity in the framework of several chiral soliton models. The Skyrme model, the Skyrme model with vector mesons and the chiral quark model are specifically treated. The vector and axial vector currents are classified according to their behavior under GG--parity. In the soliton sector particle conjugation constrains {\it a priori} ambiguous orderings of operators in the space of the collective coordinates. In the Skyrme model with vector mesons and in a local chiral model with an explicit valence quark this classification scheme provides consistency conditions for the ordering of the collective operators appearing in the 1/NC1/N_C corrections to the nucleon axial charge and the isovector magnetic moment. These consistency conditions cause the corrections obtained from an ordinary perturbation expansion to vanish in the context of the collective quantization of the static soliton configuration. This conclusion presumably applies to all local effective chiral models.Comment: 20 pages LaTeX, Conclusions made more precise, some recent references adde
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