We present results on an analysis of the decay constants f Bd and f Bs with two flavours of sea quark. The calculation has been carried out on 3 different bare gauge couplings and 4 sea quark masses at each gauge coupling, with m π /m ρ ranging from 0.8 to 0.6. We employ the Fermilab formalism to perform calculations with heavy quarks whose mass is in the range of the b-quark. A comparison with...

We present an elegant exact formula for the gaugino β-function in a softly-broken supersymmetric gauge theory, of the form β M = O(β g /g), where β g is the gauge β function and O is a simple differential operator acting on the gauge coupling g and the Yukawa

We consider general supersymmetric models with (a) arbitrary matter content and (b) gauge coupling unification near the string scale ,1017 GeV, and derive the absolute upper limit on the mass of the lightest Higgs boson. For models without Higgs couplings to extra SU(2) triplets the bound is about 155 GeV. The bound is maximized for models with such triplets and can be as high as 205 GeV, signi...

We study two and three jet events with a large rapidity gap at HERA. Unlike in the IngelmanSchlein approach we do not adscribe a structure to the Pomeron. Instead, the coupling of the Pomeron to quarks or gluons is taken pointlike, which makes the model easy to test: the only degrees of freedom are the coupling constants of the Pomeron to the quarks or the gluons and a cutoff procedure to keep ...

J. F. Xu, G. X. Peng, F. Liu, D. F. Hou, L. W. Chen School of Physics, University of Chinese Academy of Sciences, 380 Huaibeizhen, Beijing 101408, China Theoretical Physics Center for Science Facilities, Institute of High Energy Physics, Beijing 100049, China Key Lab. of QLP, Institute of Particle Physics, Huazhong Normal University, Wuhan 430079, China Department of Physics and Astronomy, Shan...

Inflationary scenarios based on simple non-minimal coupling aφ2R and its generalizations are studied. First, generalizing the form of non-minimal coupling to K(φ)R with an arbitrary function K, we show that the flat potential still is obtainable when V (φ)/K2(φ) is asymptotically constant. Very interestingly, if the ratio of the dimensionless quartic coupling(λ) of the inflaton field and the no...

I review some aspects of supersymmetric grand unification and emphasize a recent development in the area of gauge coupling unification.