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Global polarization measurement in Au+Au collisions

Description: The system created in non-central relativisticnucleus-nucleus collisions possesses large orbital angular momentum. Dueto spin-orbit coupling, particles produced in such a system could becomeglobally polarized along the direction of the system angular momentum. Wepresent the results of Lambda and anti-Lambda hyperon global polarizationmeasurements in Au+Au collisions at sqrt sNN=62.4 GeV and 200 GeVperformed with the STAR detector at RHIC. The observed globalpolarization of Lambda and anti-Lambda hyperons in the STAR acceptance isconsistent with zero within the precision of the measurements. Theobtained upper limit, lbar P Lambda, anti-Lambda rbar<= 0.02, iscompared to the theoretical values discussed recently in theliterature.
Date: August 2, 2007
Creator: Abelev, B.I.; Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett,J.; Anderson, B.D. et al.
Partner: UNT Libraries Government Documents Department


Description: Multiplicities as a function of {gamma}-ray energy have been measured for continuum {gamma}-ray spectra produced in argon- and calcium-induced reactions. A peak sometimes occurs in the multiplicity spectrum, indicating a correlation between {gamma}-ray energy and multiplicity (spin). This correlation can be explained by rotational motion of the nucleus, suggesting basically prolate nuclear shapes. Absence of structure in the multiplicity spectrum is interpreted to indicate non-collective motion, and hence spherical or oblate shapes.
Date: December 1, 1977
Creator: Deleplanque, M.A.; Lee, I.Y.; Stephens, F.S.; Diamond, R.M. & Aleonard, M.M.
Partner: UNT Libraries Government Documents Department

Parton Distributions and Spin-Orbital Correlations

Description: In this talk, I summarize a recent study showing that the large-x parton distributions contain important information on the quark orbital angular momentum of nucleon. This contribution could explain the conflict between the experimental data and the theory predictions for the polarized quark distributions. Future experiments at JLab shall provide further test for our predictions.
Date: September 24, 2007
Creator: Yuan, Feng
Partner: UNT Libraries Government Documents Department

Electron-pair excitations and the molecular Coulomb continuum

Description: Electron-pair excitations in the molecular hydrogen continuum are described by quantizing rotations of the momentum plane of the electron pair about by the pair's relative momentum. A helium-like description of the molecular pi.Joto double ionization is thus extended to higher angular momenta of the electron pair. A simple three-state superposition is found to account surprisingly well for recent observations of noncoplanar electron-pair, molecular-axis angular distributions.
Date: January 1, 2009
Creator: Colgan, James
Partner: UNT Libraries Government Documents Department

Emittance compensation studies of photoinjector beams with angular momentum

Description: Beam dynamics studies on the FNPL photo injector that seek to optimize the transport of intense electron beams with large values of canonical angular momentum have been performed. These studies investigate the effect of solenoid emittance compensation on beams that evolve under the combined influence of intense space charge forces and large angular momentum. We present details of experimental measurements and supporting simulations of beam envelope evolution.
Date: May 19, 2003
Creator: Lidia, Steven
Partner: UNT Libraries Government Documents Department


Description: Both the magnitude and alignment of the transferred angular momentum in the reaction {sup 165}Ho + {sup 165}Ho have been measured as a function of Q value via continuum {gamma}-ray multiplicity and anisotropy techniques. Two regimes are observed: A low-Q-value regime where the aligned angular momentum component dominates over the random components, and a large-Q-value regime where the random components dominate and decrease the spin alignment.
Date: July 1, 1980
Creator: Wozniak, G.J.; McDonald, R.J.; Pacheco, A.J.; Hsu, C.C.; Morrissey, D.J.; Sobotka, L.G. et al.
Partner: UNT Libraries Government Documents Department

Modified Gelfand-Tseltin patterns, lattice permutations, and skew-tableau polynomials

Description: A modification of the well-known Gelfand-Tsetlin patterns, which are one-to-one with Young-Weyl standard tableaux is introduced. These new patterns are in one-to-one correspondence with skew-tableaux, and with a slight modification can be used to enumerate lattice permutations. In particular the coupling rule for angular momentum takes an elementary form in terms of these modified patterns. These interrelations will be presented, together with an outline of the construction of a class of polynomials that generalizes the skew Schur functions.
Date: January 1, 2002
Creator: Louck, James D.
Partner: UNT Libraries Government Documents Department


Description: Gamma-ray multiplicities have been measured as a function of the light-fragment atomic number Z{sub 3} for the above reactions. The events associated with sequential fission of the heavy fragment were distinguished from binary events by means of a triple coincidence. The failure of the measured y-multiplicities for deep-inelastic collisions to rise with decreasing Z{sub 3}, according to the rigid-rotation limit, appears more likely to be associated with a selective population of the low Z fragments by the lower {ell}-waves rather than to an incomplete relaxation of the rotational energy.
Date: October 1, 1977
Creator: Aleonard, M.M.; Wozniak, G.J.; Glassel, P.; Deleplanque, M.A.; Diamond, R.M.; Moretto, L.G. et al.
Partner: UNT Libraries Government Documents Department


Description: Experimertal procedures are briefly described for the determination of the ratios of cross sections for the formation of isomeric states in nuclear reactions. Much avatlable experimertal data on isomeric yield ratios in nuclear reactions is compiled. Some of the collected data are discussed in terms of angular-momentum effects in nuclear reactions. (230 references).
Date: September 1, 1962
Creator: Wing, J.
Partner: UNT Libraries Government Documents Department

Graphical Recoupling of Angular Momenta

Description: Report presenting a diagrammatic method for solving angular momentum recoupling problems. It is shown that a few graphical elements with a set of rules for their use lead to the solution of many types of recoupling problems in an intuitive and systematic way. Several examples are given together with exercises to develop the reader's facility with the method.
Date: October 1973
Creator: Lehman, D. R. & O'Connell, J. S.
Partner: UNT Libraries Government Documents Department

Thermal rocketing and the Laser Geodynamic Satellite (LAGEOS-1)

Description: This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory. LAGEOS is the most accurately tracked satellite in orbit. It is a totally passive, dense spherical satellite covered with 426 cube corner reflectors. Besides its great utility in measuring the Earth`s length of day and polar wobble, this satellite can be used to measure, for the first time, the general relativistic frame-dragging effect. Of the five dominant error sources in such an experiment, the largest one involves surface interaction of thermal forces (thermal rocketing) and its influence on the orbital nodal precession. The project objective was to enhance an already available theoretical model (computer code) developed at Los Alamos based on new optical-spin data obtained at the University of Maryland. The project objective was met and the enhanced code will serve as the new spin-dynamics model for future LAGEOS satellite missions.
Date: August 1, 1997
Creator: Miller, W.A.
Partner: UNT Libraries Government Documents Department

The velocity peaks in the cold dark matter spectrum on earth

Description: The cold dark matter spectrum on earth is expected to have peaks in velocity space. We obtain estimates for the sizes and locations of these peaks. To this end we have generalized the secondary infall model of galactic halo formation to include angular momentum of the dark matter particles. This new model is still spherically symmetric and it has self-similar solutions. Our results are relevant to direct dark matter search experiments.
Date: April 13, 1995
Creator: Sikivie, P.; Tkachev, I.I. & Wang, Y.
Partner: UNT Libraries Government Documents Department

Derivation of the coupled equations of motion for a circular ring rotating about an axis in the plane of the ring

Description: The coupled equations of motion for a circular ring or circular ring segment are developed for the case where the ring is rotating about an axis in its plane and subjected to an angular velocity as well as an angular acceleration. Coupling results from bending in and out of the plane of the ring as well as from extension and torsion of the ring. These equations are then applied to special cases to determine the coupled equations of motion for a ring, beam and cable rotating at a constant angular speed. Coupled equations of motion for a non-rotating circular ring or circular ring segment are developed for the cases of extensional motion and inextensional motion. These equations are subsequently linearized and uncoupled for extensional and inextensional motion in the plane of the ring as well as for uncoupled motion out of the plane of the ring. The critical angular speed for lateral dynamic instability is determined for a rotating circular shaft which supports several rotating circular ring segments.
Date: March 1, 1996
Creator: Benedetti, G.A.
Partner: UNT Libraries Government Documents Department

Generation of angular-momentum-dominated electron beams from a photoinjector

Description: Various projects under study require an angular-momentum-dominated electron beam generated by a photoinjector. Some of the proposals directly use the angular-momentum-dominated beams (e.g. electron cooling of heavy ions), while others require the beam to be transformed into a flat beam (e.g. possible electron injectors for light sources and linear colliders). In this paper, we report our experimental study of an angular-momentum-dominated beam produced in a photoinjector, addressing the dependencies of angular momentum on initial conditions. We also briefly discuss the removal of angular momentum. The results of the experiment, carried out at the Fermilab/NICADD Photoinjector Laboratory, are found to be in good agreement with theoretical and numerical models.
Date: November 30, 2004
Creator: Sun, Yin-E.; Piot, Philippe; Kim, Kwang-Je; Barov, Nikolas; Lidia, Steven; Santucci, James et al.
Partner: UNT Libraries Government Documents Department

Theories for Angular Distributions in Low Energy Nuclear Reactions : A Series of Six Lectures Presented at the Lawrence Radiation Laboratory, Livermore, California, in 1958

Description: Report presenting six lectures on theories for angular distributions in low energy nuclear reactions. The topics of the lectures are "survey of reaction mechanisms", "born approximation for direct interaction theory", "semiclassical approximation for direct interaction", "distorted wave analysis and direct surface interactions", "angular correlation - general theory", and "interpretation of inelastic proton scattering by means of angular correlation theory".
Date: unknown
Creator: Moszkowski, Steven A.; Benveniste, J. & Schwarcz, E. H.
Partner: UNT Libraries Government Documents Department

Statistics of physical properties of dark matter clusters

Description: We have identified over 2000 well resolved cluster halos, and also their associated bound subhalos, from the output of 1024{sup 3} particle cosmological N-body simulation (of box size 320h{sup -1}Mpc and softening length 3.2h{sup -1}kpc). We present an algorithm to identify those halos still in the process of relaxing into dynamical equilibrium, and a detailed analysis of the integral and internal physical properties for all the halos in our sample. The majority are prolate, and tend to rotate around their minor principle axis. We find there to be no correlation between the spin and virial mass of the clusters halos and that the higher mass halos are less dynamically relaxed and have a lower concentration. Additionally, the orbital angular momentum of the substructure is typically well aligned with the rotational angular momentum of the ''host'' halo. There is also evidence of the transfer of angular momentum from subhalos to their host. Overall, we find that measured halo properties are often significantly influenced by the fraction of mass contained within substructure. Dimensionless properties do depend weakly on the ratio of halo mass (M{sub h}) to our characteristic mass scale (M{sub *} = 8 x 10{sup 14}h{sup -1}M{sub {circle_dot}}). This lack of self-similarity is in the expected sense in that, for example, ''old halos'' with M{sub h}/M{sub *} &lt;&lt; 1 have less substructure than ''young halos'' with M{sub h}/M{sub *} &gt;&gt; 1.
Date: September 1, 2005
Creator: Shaw, Laurie; Weller, Jochen; Ostriker, Jeremiah P. & Bode, Paul
Partner: UNT Libraries Government Documents Department

Gauge/Gravity Duality and Hadron Physics in the Light-Front

Description: We discuss some remarkable features of the light-front holographic mapping of classical gravity in anti-de Sitter space modified by a confining dilaton background. In particular, we show that a positive-sign dilaton solution exp(+k{sup 2}z{sup 2}) has better chances to describe the correct hadronic phenomenology than the negative solution exp (-k{sup 2}z{sup 2}) extensively studied in the literature. We also show that the use of twist-scaling dimensions, instead of canonical dimensions, is required to give a good description of the spectrum and form factors of hadrons. Another key element is the explicit connection of AdS modes of total angular momentum J with the internal structure of hadrons and the proper identification of the orbital angular momentum of the constituents.
Date: August 25, 2010
Creator: de Teramond, Guy F.; U., /Costa Rica; Brodsky, Stanley J. & /SLAC /Southern Denmark U., CP3-Origins
Partner: UNT Libraries Government Documents Department