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Hadronic final state predictions from CCFM: the hadron-level Monte Carlo generator Cascade

European Physical Journal C Springer Nature 19:2 (2001) 351-360

Authors:

H Jung, GP Salam

Revisiting non-perturbative effects in the jet broadenings

EPJ direct Springer Nature 3:1 (2001) 1-1

Authors:

Yu L Dokshitzer, G Marchesini, GP Salam

On the canonical c-function in 4-d field theories possessing supergravity duals

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 498:3-4 (2001) 285-294

Authors:

M Porrati, A Starinets

Abstract:

We study monotonicity and other properties of the canonical c-function (defined through the correlator of the energy-momentum tensor) in some holographic duals of 4-d quantum field theories. The canonical c-function and its derivatives are related to the 5d Green's function of the dual supergravity theory. While positivity of the canonical c-function is obvious, we have not found a general proof of its monotonicity, even though c is monotonic in the few explicit examples we examine in this Letter. 漏 2001 Published by Elsevier Science B.V.

The Convergence of Yang-Mills Integrals

(2001)

Authors:

Peter Austing, John F Wheater

A Minimal S^1/(Z_2 x Z_2') Orbifold GUT

Nucl.Phys.B 613 (2001) 3-16

Authors:

A Hebecker, J March-Russell

Abstract:

We investigate supersymmetric SU(5) grand-unified theories (GUTs) realized in 5 space-time dimensions and broken down to the MSSM by SU(5)-violating boundary conditions on a S^1/(Z_2 x Z_2') orbifold with two 3-branes. The doublet-triplet splitting problem is entirely avoided by locating the MSSM Higgs doublets on the brane on which SU(5) is not a good symmetry. An extremely simple model is then described in which the MSSM matter is also located on this SU(5)-violating brane. Although this model does not unify the MSSM matter within SU(5) multiplets, it explains gauge coupling unification. A second model with MSSM matter in the SU(5)-symmetric bulk preserves both the SU(5) explanation of fermion quantum numbers as well as gauge-coupling unification. Both models naturally avoid problematic SU(5) predictions for the Yukawa couplings of the first two generations and are consistent with proton decay constraints. We analyse the running of gauge couplings above the compactification scale in terms of a 5d effective action and derive the implications for the values of compactification scale, unification scale and of the scale at which the bulk gauge theory becomes strongly coupled.