Target Mass Corrections to QCD Bjorken Sum Rule for Nucleon Spin Structure Functions

We discuss the possible target mass corrections in the QCD analysis of nucleon's spin-dependent structure functions measured in the polarized deep-inelastic leptoproduction. The target mass correction for the QCD Bjorken sum rule is obtained from the Nachtmann moment and its magnitude is estimated employing positivity bound as well as the experimental data for the asymmetry parameters. We also study the uncertainty due to target mass effects in determining the QCD effective coupling constant $\alpha_s(Q^2)$ from the Bjorken sum rule. The target mass effect for the Ellis-Jaffe sum rule is also briefly discussed.Comment: 9 pages, LaTeX, 1 figure (.ps files) appended after \end{document} as an uuencoded compressed tar fil

Nonlinear Realization of Partially Broken N=2 Superconformal Symmetry in Four Dimensions

We investigate the nonlinear realization of spontaneously broken N=2 superconformal symmetry in 4 dimensions. We particularly study Nambu-Goldstone degrees of freedom for the partial breaking of N=2 superconformal symmetry down to N=1 super-Poincar{\'e} symmetry, where we get the chiral NG multiplet of dilaton and the vector NG multiplet of NG fermion of broken Q-supersymmetry. Evaluating the covariant differentials and supervielbeins for the chiral as well as the full superspace, we obtain the nonlinear effective lagrangians.Comment: 14 pages, LaTeX, minor typos correcte

Polarized and Unpolarized Structures of the Virtual Photon

We discuss the structure functions and the parton distributions in the virtual photon target, both polarized and unpolarized, beyond the leading order in QCD. We study the factorization-scheme dependence of the parton distributions.Comment: 6 pages, LaTeX, 4 postscript figures, uses aipproc.sty, Talk given at "PHOTON2000", Ambleside, UK, August 2000, to appear in the proceeding

Factorization Scheme and Parton Distributions in the Polarized Virtual Photon Target

We investigate spin-dependent parton distributions in the polarized virtual photon target in perturbative QCD up to the next-to-leading order (NLO). In the case $\Lambda^2 \ll P^2 \ll Q^2$, where $-Q^2$ ($-P^2$) is the mass squared of the probe (target) photon, parton distributions can be predicted completely up to NLO, but they are factorization-scheme-dependent.We analyze parton distributions in six different factorization schemes and discuss their scheme dependence. We study, in particular, the QCD and QED axial anomaly effects on the first moments of parton distributions to see the interplay between the axial anomalies and factorization schemes. We also show that the factorization-scheme dependence is characterized by the large-$x$ behaviors of quark distributions in the virtual photon. Gluon distribution is predicted to be the same up to NLO among the six factorization schemes examined. In particular, the first moment of gluon distribution is found to be factorization-scheme independent up to NLO.Comment: 42 pages, LaTeX, 7 Postscript Figures, eqsection.sty file included; introduction and section 5 shortened, appendix D delete

CP-odd Higgs Boson Production in eγe\gamma Collisions

We investigate the CP-odd Higgs boson production via two-photon processes in $e\gamma$ collisions. The CP-odd Higgs boson, which we denote as $A^0$, is expected to appear in the Two-Higgs Doublet Models (2HDM) as a minimal extension of Higgs sector for which the Minimal Supersymmetric Standard Model (MSSM) is a special case. The scattering amplitude for $e\gamma\rightarrow eA^0$ is evaluated at the electroweak one-loop level. The dominant contribution comes only from top-quark loops when $A^0$ boson is rather light and $\tan\beta$ is not large. There are no contributions from the $W$-boson and $Z$-boson loops nor from the scalar top-quark (stop) loops. The differential cross section for the $A^0$ production is analysed.Comment: PDFLatex, elsarticle.cls used, 5 pages, 7 PDF figures. Revised arguments in sections 2 and 3. Added one figure and references.Results unchange

Quantum Conserved Charges and S-matrices in N=2 Supersymmetric Sine-Gordon Theory

We study the quantum conserved charges and S-matrices of N=2 supersymmetric sine-Gordon theory in the framework of perturbation theory formulated in N=2 superspace. The quantum affine algebras ${\widehat {sl_{q}(2)}}$ and super topological charges play important roles in determining the N=2 soliton structure and S-matrices of soliton-(anti)soliton as well as soliton-breather scattering.Comment: 22 page

Heavy Quark Effects in the Virtual Photon Structure Functions

We investigate the heavy quark mass effects in the virtual photon structure functions $F_{2}^{\gamma}(x, Q^2, P^2)$ and $F_{L}^{\gamma}(x, Q^2, P^2)$ in the framework of the mass-independent renormalization group equation (RGE). We study a formalism in which the heavy quark mass effects are treated based on parton picture as well as on the operator product expansion (OPE), and perform the numerical evaluation of $F_{\rm eff}^{\gamma}(x, Q^2, P^2)$ to the next-leading order (NLO) in QCD.Comment: 19 pages, LaTeX, 4 eps figures, PTPTe