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M Justice

Publications and source records attributed to M Justice.

At least 19 recordsLinked to original sources
PubMed2001

Model-independent source imaging using two-pion correlations in (2 to 8)a GeV Au+Au collisions.

We report a particle source imaging analysis based on two-pion correlations in high multiplicity Au+Au collisions at beam energies between 2A and 8A GeV. We apply the imaging technique introduced by Brown and Danielewicz, which allows a model-independent extraction of source functions with useful accuracy out to relative pion separations of about 20 fm. The extracted source functions have Gaussian shapes. Values of source functions at zero separation are almost constant across the energy range under study. Imaging results are found to be consistent with conventional source parameters obtained from a multidimensional Hanburg-Brown-Twiss analysis.

Journal Article↗
PubMed2001

Directed flow of lambda hyperons in (2-6 )A GeV Au+Au collisions.

Directed flow measurements for Lambda hyperons are presented and compared to those for protons produced in the same Au+Au collisions (2A, 4A, and 6A GeV; b<5-6 fm). The measurements indicate that Lambda hyperons flow consistently in the same direction but with smaller magnitudes. A strong positive flow [for Lambdas] has been predicted in calculations which include the influence of the Lambda-nucleon potential. The experimental flow ratio Lambda/p is in qualitative agreement with expectations (approximately 2/3) from the quark counting rule at 2A GeV but is found to decrease with increasing beam energy.

Journal Article↗
PubMed2001

Evaluating mutant mice: anatomic pathology.

As the human and mouse genome projects approach their goals, initiatives in functional genomics are advancing. When the nucleotide sequences are available, identification of gene functions will assume even greater importance. Determination of gene products and their proximal biochemical functions provide a part of the picture, but determination of their functions in the context of the whole organism is the ultimate goal. The manipulated mouse genome has become accepted as a model for understanding the genetic basis of human conditions and diseases. Consequently, biomedical research institutions have seen significant increases in the use of mice since the early 1980s, and these increases are largely attributable to the use of genetically modified mice. The role of comparative pathology in research on mutant mouse models of disease is increasing in response to these trends. Evaluation and phenotypic characterization of mutant mice, via clinical and anatomic pathology techniques, will be an important component of functional genomics initiatives.

Animal Identification Systems↗
PubMed2000

Semi-inclusive lambda and K(S) production in p-Au collisions at 17.5 GeV/c

The first detailed measurements of the centrality dependence of strangeness production in p-A collisions are presented. Lambda and K(S) dn/dy distributions from 17.5 GeV/ c p-Au collisions are shown as a function of "grey" track multiplicity and the estimated number of collisions, nu, made by the proton. The nu dependence of the Lambda yield deviates from a scaling of p-p data by the number of participants, increasing faster than this scaling for nu</=5 and saturating for larger nu. A slower growth in K(S) multiplicity with nu is observed, consistent with a weaker nu dependence of K&Kmacr; production than YK production.

Journal Article↗
PubMed2000

Nuclear multifragmentation, percolation, and the fisher droplet model: common features of reducibility and thermal scaling

It is shown that the Fisher droplet model, percolation, and nuclear multifragmentation share the common features of reducibility (stochasticity in multiplicity distributions) and thermal scaling (one-fragment production probabilities are Boltzmann factors). Barriers obtained, for cluster production on percolation lattices, from the Boltzmann factors show a power-law dependence on cluster size with an exponent of 0.42+/-0.02. The EOS Collaboration Au multifragmentation data yield barriers with a power-law exponent of 0.68+/-0.03. Values of the surface energy coefficient of a low density nuclear system are also extracted.

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PubMed2000

Antiflow of K(0)(s) mesons in 6A GeV Au + Au collisions

We have measured the sideward flow of neutral strange ( K(0)(s)) mesons in 6A GeV Au+Au collisions. A prominent antiflow signal is observed for an impact parameter range ( b less, similar7 fm) which spans central and midcentral events. Since the K(0)(s) scattering cross section is relatively small in nuclear matter, this observation suggests that the in-medium kaon vector potential plays an important role in high density nuclear matter.

Journal Article↗
PubMed2000

Sideward flow in Au+Au collisions between 2A and 8A GeV

Using the large acceptance Time Projection Chamber of experiment E895 at Brookhaven, measurements of collective sideward flow in Au+Au collisions at beam energies of 2A, 4A, 6A, and 8A GeV are presented in the form of in-plane transverse momentum and the first Fourier coefficient of azimuthal anisotropy v(1). These measurements indicate a smooth variation of sideward flow as a function of beam energy. The data are compared with four nuclear transport models which have an orientation towards this energy range. All four exhibit some qualitative trends similar to those found in the data, although none show a consistent pattern of agreement within experimental uncertainties.

Journal Article↗
PubMed2000

Bombarding energy dependence of pi(-) interferometry at the brookhaven AGS

We present the first excitation function of pi(-) intensity interferometry at Alternating Gradient Synchrotron (AGS) energies (2-8 A GeV). The sensitivity of the multidimensional correlation functions to the geometry and dynamics of the pion-emitting system provides a stringent test of transport models of heavy ion collisions. Detailed comparisons with a realistic transport model, both with and without an explicit nuclear mean field, suggest that the beam energy evolution in the reaction dynamics is different in the model than in the data. A significantly increased pi(-) emission time scale, which has been suggested as a signal of the onset of the transition to quark-gluon plasma, is not observed.

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