Study of Leading Hadrons in Gluon and Quark Fragmentation

The study of quark jets in e+e- reactions at LEP has demonstrated that the hadronisation process is reproduced well by the Lund string model. However, our understanding of gluon fragmentation is less complete. In this study enriched quark and gluon jet samples of different purities are selected in three-jet events from hadronic decays of the Z collected by the DELPHI experiment in the LEP runs during 1994 and 1995. The leading systems of the two kinds of jets are defined by requiring a rapidity gap and their sum of charges is studied. An excess of leading systems with total charge zero is found for gluon jets in all cases, when compared to Monte Carlo Simulations with JETSET (with and without Bose-Einstein correlations included) and ARIADNE. The corresponding leading systems of quark jets do not exhibit such an excess. The influence of the gap size and of the gluon purity on the effect is studied and a concentration of the excess of neutral leading systems at low invariant masses (<~ 2 GeV/c^2) is observed, indicating that gluon jets might have an additional hitherto undetected fragmentation mode via a two-gluon system. This could be an indication of a possible production of gluonic states as predicted by QCD.Comment: 19 pages, 6 figures, Accepted by Phys. Lett.

Production of Xi_c^0 and Xi_b in Z decays and lifetime measurement of Xi_b

The charmed strange baryon Xi_c^0 was searched for in the decay channel Xi_c^0 -> Xi- pi+, and the beauty strange baryon Xi_b in the inclusive channel Xi_b -> Xi- l- anti-nu X, using the 3.5 million hadronic Z events collected by the DELPHI experiment in the years 1992--1995. The Xi- was reconstructed through the decay Xi- -> Lambda pi-, using a constrained fit method for cascade decays. An iterative discriminant analysis was used for the Xi_c^0 and Xi_b selection. The production rates were measured to be f_{Xi_c^0} x BR(Xi_c^0 -> Xi- pi+)= (4.7 +/- 1.4 (stat.) +/- 1.1 (syst.))10^{-4} per hadronic Z decay, and BR(b -> Xi_b) x BR(Xi_b -> Xi- l- X)= (3.0 +/- 1.0 (stat.) +/- 0.3 (syst.))10^{-4} for each lepton species (electron or muon). The lifetime of the Xi_b baryon was measured to be tau_{Xi_b} = 1.45{^{+0.55}_{-0.43}} (stat.) +/- 0.13 (syst.) ps. A combination with the previous DELPHI lifetime measurement gives tau_{Xi_b} = 1.48{^{+0.40}_{-0.31}} (stat.) +/- 0.12 (syst.) ps.Comment: 21 pages, 9 figures, Accepted by Eur. Phys. J.

Investigation of the accuracy, efficiency and applicability of the method of moments as numerical dosimetry tool for the head and hand of a mobile phone user.

IngenieursweseElektriese En Elektroniese IngeniePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Analysis of finite antenna arrays in the presence of arbitrary electromagnetic structures

© 2015 IEEE. This work considers the analysis of finite antenna arrays in the presence of arbitrary electromagnetic structures, e.g. a focal plane array illuminating a parabolic dish antenna, or an antenna array located above a finite sized ground plane. The fast solution approach applies domain decomposition where the finite array is considered as one domain and the remainder of the geometry as the other. Two Method-of-Moment (MoM) based strategies will be considered to analyse the coupling between the domains, viz. The Numerical Greens Function Method (NGF) as well as an Iterative Field Bouncing (IFB) scheme. These methods will be compared in terms of accuracy and runtime when used to analyse a bow-tie antenna array situated above a finite size ground plane

Numerical Analysis of Finite Antenna Arrays using the Domain Green�s Function Method

IngenieursweseElektriese En Elektroniese IngeniePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Extensions to the hybrid method of moments/uniform GTD formulation for sources located close to a smooth convex surface.

IngenieursweseElektriese En Elektroniese IngeniePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]