6 papers
Positivity constraints on photon structure functions
K. Sasaki, J. Soffer, T. Uematsu
We investigate the positivity constraints for the structure functions of both virtual and real photon. From the Cauchy-Schwarz inequality we derive three positivity conditions for…
Factorization Scheme and Parton Distributions in the Polarized Virtual Photon Target
Ken Sasaki, Tsuneo Uematsu
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 $Λ^2 \ll P^2 \ll Q^…
Two-loop electroweak corrections to the parameter beyond the leading approximation
Joannis Papavassiliou, Kostas Philippides, Ken Sasaki
We show that in the framework of the pinch technique the universal part of the parameter can be meaningfully defined, beyond one loop. The universal part so obtained satisfies…
Muonium-Antimuonium Conversion in Models with Dilepton Gauge Bosons
Kuninori Horikawa, Ken Sasaki
We examine the magnetic field dependence of the muonium() - antimuonium() conversion in the models which accommodate the dilepton gauge bosons. The effective Hami…
The Background Field Method: Alternative Way of Deriving the Pinch Technique's Results
Shoji Hashimoto, Jiro Kodaira, Yoshiaki Yasui +1
We show that the background field method (BFM) is a simple way of deriving the same gauge-invariant results which are obtained by the pinch technique (PT). For illustration we cons…
The Mass of the Lightest Supersymmetric Higgs Boson beyond the Leading Logarithm Approximation
Jiro Kodaira, Yoshiaki Yasui, Ken Sasaki
We examine the radiative corrections to the mass of the lightest Higgs boson in the minimal supersymmetric extension of the standard model. We use the renormalization-group improve…