131 research outputs found
Semiclassical cross section correlations
We calculate within a semiclassical approximation the autocorrelation
function of cross sections. The starting point is the semiclassical expression
for the diagonal matrix elements of an operator. For general operators with a
smooth classical limit the autocorrelation function of such matrix elements has
two contributions with relative weights determined by classical dynamics. We
show how the random matrix result can be obtained if the operator approaches a
projector onto a single initial state. The expressions are verified in
calculations for the kicked rotor.Comment: 6 pages, 2 figure
Modelling Hurricane Exposure and Wind Speed on a Mesoclimate Scale: A Case Study from Cusuco NP, Honduras
High energy weather events are often expected to play a substantial role in biotic community dynamics and large scale diversity patterns but their contribution is hard to prove. Currently, observations are limited to the documentation of accidental records after the passing of such events. A more comprehensive approach is synthesising weather events in a location over a long time period, ideally at a high spatial resolution and on a large geographic scale. We provide a detailed overview on how to generate hurricane exposure data at a meso-climate level for a specific region. As a case study we modelled landscape hurricane exposure in Cusuco National Park (CNP), Honduras with a resolution of 50 mĂ—50 m patches. We calculated actual hurricane exposure vulnerability site scores (EVVS) through the combination of a wind pressure model, an exposure model that can incorporate simple wind dynamics within a 3-dimensional landscape and the integration of historical hurricanes data. The EVSS was calculated as a weighted function of sites exposure, hurricane frequency and maximum wind velocity. Eleven hurricanes were found to have affected CNP between 1995 and 2010. The highest EVSS's were predicted to be on South and South-East facing sites of the park. Ground validation demonstrated that the South-solution (i.e. the South wind inflow direction) explained most of the observed tree damage (90% of the observed tree damage in the field). Incorporating historical data to the model to calculate actual hurricane exposure values, instead of potential exposure values, increased the model fit by 50%
Management Seminar Management Survey of the Simmons Machine Tool Corporation Albany, New York V. 3
In three volumes, available under http://hdl.handle.net/10945/14399 (vol. 1); http://hdl.handle.net/10945/14402 (vol. 2); http://hdl.handle.net/10945/14405 (vol. 3)http://www.archive.org/details/managementsurvey03abelU.S. Navy (U.S.N.) authors.U.S. Marine Corps (U.S.M.C.) authors
Effects of T- and P-odd weak nucleon interaction in nuclei: renormalizations due to residual strong interaction, matrix elements between compound states and their correlations with P-violating matrix elements
Manifestations of P-,T-odd weak interaction between nucleons in nucleus are
considered. Renormalization of this interaction due to residual strong
interaction is studied. Mean squared matrix elements of P-,T-odd weak
interaction between compound states are calculated. Correlators between
P-,T-odd and P-odd, T-even weak interaction matrix elements between compound
states are considered and estimates for these quantities are obtained.Comment: Submitted to Phys. Rev. C; 21 pages, REVTEX 3, no figure
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TECHNICAL DESIGN REPORT FOR A NOSECONE CALORIMETER (NCC) FOR THE PHENIX EXPERIMENT.
A remarkable result has emerged from the first several years of data taking at RHIC--the high temperature and density phase of QCD matter created in heavy ion collisions at RHIC is best described as a near perfect fluid--the strongly interacting Quark-Gluon-Plasma (sQGP). This state is characterized by a small viscosity to entropy ratio, and a high density of color charges which induces huge energy losses of partons transversing the medium. The task for the future is to understand the characteristics of the sQGP, and perhaps more importantly--to gain some insight into how and why such a medium is created. The PHENIX detector has been one of the primary experimental tools at RHIC; in particular the electromagnetic calorimeter has been a critical component of many of the measurements leading to this discovery. The coverage of the present PHENIX electromagnetic calorimeter is rather limited, covering half the azimuth and -0.35< {eta} <0.35 Further progress requires larger coverage of electromagnetic calorimetry, both to increase the rate for low cross section phenomena, and to cover a broader range of pseudorapidity to study the rapidity dependence of the medium. A pair of Nosecone Calorimeters (NCC) has been designed covering both positive and negative rapidity regions 1< |{eta}| <3 of the PHENIX detector. The NCC will make it possible to perform tomographic studies of the jet energy dependence of energy loss and medium response, by using direct photons as trigger particles over a large rapidity range. The technique of correlating trigger hadrons with low momentum hadrons has been powerfully exploited at RHIC to study the evolution of back to back jets [1, 2] and hence the response of the medium. The NCC will make it possible to do such studies using direct photons as the trigger particles. The direct photon in such ''photon-jet'' events tags the transverse momentum of outgoing parton which then fragments into lower energy particles. Together with the Forward Silicon Vertex detector (FVTX), the NCC will make PHENIX a large acceptance spectrometer, capable of detecting photons, electrons, muons, and hadrons. Our prime motivation is to provide precision measurements of direct photons, {pi}{sup 0}s and dielectrons in A+A, p(d)+A, and polarized p+p collisions. The upgrade will provide access to physics observables that are not currently accessible to PHENIX or that are now available only indirectly with very limited accuracy
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