12,927 research outputs found
Clustering and Correlations at the Neutron Dripline
Some recent experimental studies of clustering and correlations within very
neutron-rich light nuclei are reviewed. In particular, the development of the
novel probes of neutron-neutron interferometry and Dalitz-plot analyses is
presented through the example of the dissociation of the two-neutron halo
system Be. The utility of high-energy proton radiative capture is
illustrated using a study of the He(p,) reaction. A new approach
to the production and detection of bound neutron clusters is also described,
and the observation of events with the characteristics expected for
tetraneutrons (n) liberated in the breakup of Be is discussed. The
prospects for future work, including systems beyond the neutron dripline, are
briefly outlined.Comment: Invited contribution to a topical issue on Exotic Nuclei of Les
Comptes Rendus de l'Academie des Sciences Paris, Serie IV. 29 pages,11
figures (format RevTex preprint
Bayesian Analysis of Simple Random Densities
A tractable nonparametric prior over densities is introduced which is closed
under sampling and exhibits proper posterior asymptotics.Comment: 19 pages; 6 figure
Predictive analysis of microarray data
Microarray gene expression data are analyzed by means of a Bayesian
nonparametric model, with emphasis on prediction of future observables,
yielding a method for selection of differentially expressed genes and a
classifier
Effect of particle polydispersity on the irreversible adsorption of fine particles on patterned substrates
We performed extensive Monte Carlo simulations of the irreversible adsorption
of polydispersed disks inside the cells of a patterned substrate. The model
captures relevant features of the irreversible adsorption of spherical
colloidal particles on patterned substrates. The pattern consists of (equal)
square cells, where adsorption can take place, centered at the vertices of a
square lattice. Two independent, dimensionless parameters are required to
control the geometry of the pattern, namely, the cell size and cell-cell
distance, measured in terms of the average particle diameter. However, to
describe the phase diagram, two additional dimensionless parameters, the
minimum and maximum particle radii are also required. We find that the
transition between any two adjacent regions of the phase diagram solely depends
on the largest and smallest particle sizes, but not on the shape of the
distribution function of the radii. We consider size dispersions up-to 20% of
the average radius using a physically motivated truncated Gaussian-size
distribution, and focus on the regime where adsorbing particles do not interact
with those previously adsorbed on neighboring cells to characterize the jammed
state structure. The study generalizes previous exact relations on monodisperse
particles to account for size dispersion. Due to the presence of the pattern,
the coverage shows a non-monotonic dependence on the cell size. The pattern
also affects the radius of adsorbed particles, where one observes preferential
adsorption of smaller radii particularly at high polydispersity.Comment: 9 pages, 5 figure
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