Time division access feasibility study modulation and synchronization considerations

Time division access system for satellite communications, and figure of merit for effects of bit and frequency synchronizatio

Search for Narrow-Width ttbar Resonances in ppbar Collisions at center of mass energy = 1.8 TeV

We present a preliminary result on a search for narrow-width resonances that decay into ttbar pairs using 130 pb^{-1} of lepton plus jets data in ppbar collisions at center of mass energy = 1.8 TeV. No significant deviation from Standard Model prediction is observed. 95% C.L. upper limits on the production cross section of the narrow-width resonance times its branching fraction to ttbar are presented for different resonance masses, M_X. We also exclude the existence of a leptophobic topcolor particle, X, with M_X < 560 GeV/c^2 for a width \Gamma_X = 0.012 M_X.Comment: 3 pages, 1 figure; Submitted for proceedings of 5th International Conference on Quark Confinement and Hadron spectrum, held in Italy, from 11-14 Sep., 200

The Quantum de Laval Nozzle: stability and quantum dynamics of sonic horizons in a toroidally trapped Bose gas containing a superflow

We study an experimentally realizable system containing stable black hole-white hole acoustic horizons in toroidally trapped Bose-Einstein condensates - the quantum de Laval nozzle. We numerically obtain stationary flow configurations and assess their stability using Bogoliubov theory, finding both in hydrodynamic and non-hydrodynamic regimes there exist dynamically unstable regions associated with the creation of positive and negative energy quasiparticle pairs in analogy with the gravitational Hawking effect. The dynamical instability takes the form of a two mode squeezing interaction between resonant pairs of Bogoliubov modes. We study the evolution of dynamically unstable flows using the truncated Wigner method, which confirms the two mode squeezed state picture of the analogue Hawking effect for low winding number.Comment: 12 pages, 10 figure

Magneto-Spectral Studies on Some Trivalent Metal Complexes: Chromium, Iron and Cobalt Complexes Derived from 4-Benzylamidothiosemicarbazide and its Thiosemicarbazone.

Complexes of chromium(Ill), iron(lll) and cobalt(III) with 4-benzy lamidothiosemicarbazide (BTSC) and 1-( a-)fury 1-4-benzy lamidothiosemicarbazone (FBTS) have been prepared and characterized by conventional chemical and physical measurements. Tetragonal symmetry has been proposed for these complexes on the basis of electronic spectral data. The various ligand field pp.rameteres have been evaluated, wherever possible. The infrared spectral studies indicate the S-N- bidentate nature of both ligands

Welcome address

This is my privilege to welcome you all to the steel city of Jamshedpur, built by the greatest Indian pioneering industrialist Jamshedji Tata, its adjacent area abundant with valuable minerals and ores. At NML the first flowsheet of a modern mineral beneficition plant was being attem-pted successfully in the early sixties. Thus, the seminar on crushing and grinding-practices, problems and prospects is a fitting tribute to the city and NML

Composite fermion wave functions as conformal field theory correlators

It is known that a subset of fractional quantum Hall wave functions has been expressed as conformal field theory (CFT) correlators, notably the Laughlin wave function at filling factor $\nu=1/m$ ($m$ odd) and its quasiholes, and the Pfaffian wave function at $\nu=1/2$ and its quasiholes. We develop a general scheme for constructing composite-fermion (CF) wave functions from conformal field theory. Quasiparticles at $\nu=1/m$ are created by inserting anyonic vertex operators, $P_{\frac{1}{m}}(z)$, that replace a subset of the electron operators in the correlator. The one-quasiparticle wave function is identical to the corresponding CF wave function, and the two-quasiparticle wave function has correct fractional charge and statistics and is numerically almost identical to the corresponding CF wave function. We further show how to exactly represent the CF wavefunctions in the Jain series $\nu = s/(2sp+1)$ as the CFT correlators of a new type of fermionic vertex operators, $V_{p,n}(z)$, constructed from $n$ free compactified bosons; these operators provide the CFT representation of composite fermions carrying $2p$ flux quanta in the $n^{\rm th}$ CF Landau level. We also construct the corresponding quasiparticle- and quasihole operators and argue that they have the expected fractional charge and statistics. For filling fractions 2/5 and 3/7 we show that the chiral CFTs that describe the bulk wave functions are identical to those given by Wen's general classification of quantum Hall states in terms of $K$-matrices and $l$- and $t$-vectors, and we propose that to be generally true. Our results suggest a general procedure for constructing quasiparticle wave functions for other fractional Hall states, as well as for constructing ground states at filling fractions not contained in the principal Jain series.Comment: 26 pages, 3 figure