On the basis of the relation between values of the coupling constants determined from data fit it is concluded that the dominating constituent of the Θ meson is the glueball. The possibility that Θ meson decays into two σ(750) mesons is suggested. ∗ E-mail: [email protected]

M. WOBISCH III. Physikalisches Institut, RWTH Aachen, D-52056 Aachen, Germany, E-mail: [email protected] Various QCD studies based on jet observables in hadronic nal states in deep-inelastic scattering and in hadron-hadron collisions are presented. Measured quantities are event shape variables, jet rates and jet cross sections. QCD analyses have been performed to determine the value of the...

Taking into account uncertainties related with the initial coupling constants and threshold corrections at low and high scales we find that in standard supersym-metric SU (5) model the supersymmetry breaking scale could be up to 10 8 GeV.

We use an auxiliary field construction to discuss the hard thermal loop effective action associated with massless thermal SU(N) QCD interacting with a weak gravitational field. It is demonstrated that the previous attempt to derive this effective action has only been partially successful and that it is presently only known to first order in the graviton coupling constant. This is still sufficie...

In the present paper, using powerful tools of harmonic maps and integrable systems, all the Gribov copies in the Coulomb gauge in 3D Chern-Simons theory are constructed. This result strongly suggets that the so-called uniton number (known in the theory of harmonic maps) could be related to the well known shift of the Chern-Simons coupling constant. The Gribov copies of the vacuum in 3D QCD in t...

A generalized version of the TROSY experiment allows the spin-state selective editing of the four multiplet components of N–H cross peaks of amide groups in proteins into four different subspectra, with no penalty in sensitivity. An improvement by Î2 in sensitivity results, if only two of the four multiplet components are selected. Use of the experiment for the measurement of JHN coupling const...

A class of finite GUTs in curved spacetime is considered in connection with the cosmological inflation scenario. It is confirmed that the running of the scalar-gravitational coupling constant in these models helps realizing the successful chaotic inflation. The analyses are made for some different sets of the models.

From an accurate determination of the inter-quark potential, one can study the running coupling constant for a range of R-values and hence estimate the scale Λ MS. Detailed results are presented for SU (3) pure gauge theory from a study of a 36 4 lattice at β = 6.5.

The status of coupling constant unification in standard supersymmetric SU (5) model and its extensions is discussed. Taking into account uncertainties related with the initial coupling constants and threshold corrections at the low and high scales we find that in standard supersymmetric SU (5) model the scale of the supersymmetry breaking could be up to 10 8 Gev. In the extensions of standard S...

In the framework of noncompact lattice QED with light fermions, we derive the functional dependence of the average energy per plaquette on the bare parameters using block-spin Renormalization Group arguments and assuming that the renormalized coupling vanishes. Our numerical results for this quantity in 8 4 and 10 4 lattices show evidence for triviality in the weak coupling phase and point to a...