Correlations in a BEC collision: First-principles quantum dynamics with 150 000 atoms

The quantum dynamics of colliding Bose-Einstein condensates with 150 000 atoms are simulated directly from the Hamiltonian using the stochastic positive-P method. Two-body correlations between the scattered atoms and their velocity distribution are found for experimentally accessible parameters. Hanbury Brown-Twiss or thermal-like correlations are seen for copropagating atoms, while number correlations for counterpropagating atoms are even stronger than thermal correlations at short times. The coherent phase grains grow in size as the collision progresses with the onset of growth coinciding with the beginning of stimulated scattering. The method is versatile and usable for a range of cold atom systems.Comment: 4 pages, 4 figures. v2: Rewording and style changes, minor except for rewrite of background on the positive-P representation. Original research unchange

Linear Collider Workshop 2000 Summary

We summarize some of the main physics questions that will serve to define the linear e+e- collider program, and comment on issues that confront the world community in making such a collider a reality.Comment: 16 pp, Summary of Linear Collider Workshop, FNAL Oct. 200

Frequency shift keying apparatus Patent

Frequency shift keying apparatus for use with pulse code modulation data transmission syste

Novel horn antenna reduces side lobes, improves radiation pattern

A horn antenna, combining two propagation modes at selected power ratios, reduces side lobes, and improves the radiation characteristics. Noise and unwanted signals are considerably suppressed

Nuclear Dynamics with the Sky3D code

A description is presented of how to use the Sky3D time-dependent Hartree-Fock code to calculate giant monopole resonances. This requires modification to the code, and a step-by-step guide of how to make the necessary modification is given. An example of how to analyse the output of the code to obtain quantities of physics interest is included. Together, the modifications and the post-processing are intended to serve as a typical example of how the code, which was designed to be extendable to particular users' needs, can be extended.Comment: submitted to Proceedings of the International Workshop on Nuclear Theory 33 (Rila, Bulgaria

Search for the Invisibly Decaying Higgs Particle at LEP and the LHC

The Higgs particle can have dominantly invisible decay in a large class of Majoron models as well as some SUSY models. The LEP signal and mass limit for a Higgs particle undergoing invisible decay are explored. They are found to be very similar to those for the standard model decay. The best signatures and discovery limit for an invisibly decaying Higgs particle at the LHC are also discussed. (Invited Talk at the XXIXth Rencontres de Moriond on QCD and High Energy Hadronic Interactions, M\'eribel, France, 19--26 March 1994.)Comment: 5 Pages + 3 figures available on request, CERN-TH.7221/9

That Some of Sol Lewitt's Later Wall Drawings Aren't Wall Drawings

Sol LeWitt is probably most famous for wall drawings. They are an extension of work he had done in sculpture and on paper, in which a simple rule specifies permutations and variations of elements. With wall drawings, the rule is given for marks to be made on a wall. We should distinguish these algorithmic works from impossible-to-implement instruction works and works realized by following preparatory sketches. Taking the core feature of a wall drawing to be that it is algorithmic, some of LeWitt's later works are wall drawings in name only