4,670 research outputs found
Multiplicity dependence of correlation functions in \bar{p}p reactions at sqrt(s) = 630 GeV
Discussions about Bose-Einstein correlations between decay products of
coproduced W-bosons again raise the question about the behaviour of
correlations if several strings are produced. This is studied by the
multiplicity dependence of correlation functions of particle pairs with
like-sign and opposite-sign charge in \bar{p}p reactions at sqrt{s} = 630 GeV.Comment: 11 pages latex, 4 figs, includes elsart.cls, submitted to Phys Lett
WHITEâCROWNED MANAKIN (DIXIPHIA PIPRA) USE OF SPACE IN THE ECUADORIAN AMAZON
Abstract â Animal patterns of space use have fundamental consequences for ecological processes such as animalâ mediated seed dispersal. This study examines the use of space of an understory frugivore: the Whiteâcrowned Manakin (Dixiphia pipra) during the nonâbreeding season at Tiputini Biodiversity Station in Ecuador. We radioâtracked seven individuals of different sexes and ages. We found that Whiteâcrowned Manakins have relatively small home ranges varying from 1.19 to 5.73 ha. The home ranges of male juveniles (2.25 ± 0.62 SE) were larger than that of the adult males (1.20 ± 0.01 SE), but smaller than those of females (4.27 ± 0.77 SE). Females and secondâyear males were found to perform more long distance flights outside their core home range than hatchâyear or adult males. These movement differences suggest that they disperse seeds longer distances and more evenly across their home range. Adult and hatchâyear males appear to perform more short distance seed dispersal events. We argue that these contributions are complementary, and that Whiteâcrowned Manakins are key dispersal agents that have a significantly influence in the structure and composition of understory plant communities in the Amazon rainforest.Resumen â Uso de espacio del SaltarĂn Coroniblanco (Dixiphia pipra) en la AmazonĂa Ecuatoriana Los patrones de uso espacial utilizados por animales tienen consecuencias fundamentales en procesos ecolĂłgicos, tales como la dispersiĂłn de semillas. Este estudio examina el uso espacial de una especie frugĂvora de sotobosque: el SaltarĂn Coroniblanco (Dixiphia pipra) durante el ciclo noâreproductivo en la EstaciĂłn de Biodiversidad de Tiputini en Ecuador. Seguimos por radio telemetrĂa a siete individuos de diferentes sexos y edades. Encontramos que el SaltarĂn Coroniblanco tiene un rango de hogar relativamente pequeño, variando entre 1,19 a 5,73 ha. El rango de hogar de los machos juveniles (2,25 ± 0,62 EE) es mĂĄs grande que el de los machos adultos (1,20 ± 0,01 EE), pero mĂĄs pequeño que el de las hembras (4,27 ± 0,77 EE). El estudio encontrĂł que las hembras y los machos de segundo año realizaron vuelos mĂĄs largos fuera del nĂșcleo de su rango de hogar, comparado con machos juveniles del año o machos adultos. Estas diferencias sugieren que podrĂan dispersar semillas a mayores distancias y de manera mĂĄs homogĂ©nea a lo largo de su rango de hogar. Los machos adultos y los juveniles del año parecen llevar a cabo eventos de dispersiĂłn de semillas a distancias mĂĄs cortas. Nosotros argumentamos que estas contribuciones son complementarias y que los Saltarines Coroniblancos son agentes de dispersiĂłn claves, influenciando considerablemente la estructura y la composiciĂłn de las comunidades de plantas del sotobosque en el bosque tropical lluvioso de la AmazonĂa Ecuatoriana.
Factorial Moments of Continuous Order
The normalized factorial moments are continued to noninteger values of
the order , satisfying the condition that the statistical fluctuations
remain filtered out. That is, for Poisson distribution for all .
The continuation procedure is designed with phenomenology and data analysis in
mind. Examples are given to show how can be obtained for positive and
negative values of . With being continuous, multifractal analysis is
made possible for multiplicity distributions that arise from self-similar
dynamics. A step-by-step procedure of the method is summarized in the
conclusion.Comment: 15 pages + 9 figures (figures available upon request), Late
Bounds for Bose-Einstein Correlation Functions
Bounds for the correlation functions of identical bosons are discussed for
the general case of a Gaussian density matrix. In particular, for a purely
chaotic system the two-particle correlation function must always be greater
than one. On the other hand, in the presence of a coherent component the
correlation function may take values below unity. The experimental situation is
briefly discussed.Comment: 7 pages, LaTeX, DMR-THEP-93-5/
A sensitive test for models of Bose-Einstein correlations
Accurate and sensitive measurements of higher order cumulants open up new
approaches to pion interferometry. It is now possible to test whether a given
theoretical prediction can consistently match cumulants of both second and
third order. Our consistency test utilizes a new technique combining
theoretically predicted functions with experimentally determined weights in a
quasi-Monte Carlo approach. Testing a general quantum statistics-based
framework of Bose-Einstein correlations with this technique, we find that
predictions for third order cumulants differ significantly from UA1 data. This
discrepancy may point the way to more detailed dynamical information.Comment: 5 pages, 2 figures, revte
A Color Mutation Model of Soft Interaction in High Energy Hadronic Collisions
A comprehensive model, called ECOMB, is proposed to describe multiparticle
production by soft interaction. It incorporates the eikonal formalism, parton
model, color mutation, branching and recombination. The physics is conceptually
opposite to the dynamics that underlies the fragmentation of a string. The
partons are present initially in a hadronic collision; they form a single,
large, color-neutral cluster until color mutation of the quarks leads to a
fission of the cluster into two color-neutral subclusters. The mutation and
branching processes continue until only pairs are left in each small
cluster. The model contains self-similar dynamics and exhibits scaling behavior
in the factorial moments. It can satisfactorily reproduce the intermittency
data that no other model has been able to fit.Comment: 24 pages including 11 figures in revtex epsf styl
Multi-boson effects and the normalization of the two-pion correlation function
The two-pion correlation function can be defined as a ratio of either the
measured momentum distributions or the normalized momentum space probabilities.
We show that the first alternative avoids certain ambiguities since then the
normalization of the two-pion correlator contains important information on the
multiplicity distribution of the event ensemble which is lost in the second
alternative. We illustrate this explicitly for specific classes of event
ensembles.Comment: 6 pages, three figures,submit to PR
90-yttrium-ibritumomab tiuxetan as first-line treatment for follicular lymphoma: updated efficacy and safety results at an extended median follow-up of 9.6 years
Radioimmunotherapy with 90-yttrium-ibritumomab tiuxetan (90Y-IT) as first-line treatment in patients with follicular lymphoma (FL) demonstrated promising results with a complete remission (CR) rate of 56% and a median progression-free survival (PFS) of 26 months, when initially analyzed after a median follow-up of 30.6 months. The aim of this long-term follow-up was to investigate whether clinical benefits were maintained and new safety signals appeared. Fifty-nine patients, aged â„ 50 years, with FL grade 1 to 3A in stages II to IV were treated with 90Y-IT as first-line therapy. If CR without evidence of minimal residual disease (MRD), partial response or stable disease was achieved 6 months after treatment, patients were observed without further treatment. Patients with CR but persisting MRD received consolidation therapy with rituximab. The primary endpoint was the clinical response rate. Secondary endpoints were time to progression, safety, and tolerability. After a median follow-up of 9.6 years, median PFS was 3.6 years, and 8-year PFS was 38.3%. Median overall survival (OS) was not reached during the extended follow-up, and 8-year OS amounted to 69.2%. Age 65 years and above or disease progression within 24 months of treatment were significantly associated with shorter OS. An important finding was the lack of new safety signals. In particular, no increase in secondary malignancies or transformation into aggressive lymphoma was observed compared to trials with a similar follow-up. In summary, 90Y-IT as first-line treatment demonstrates a favorable safety profile and long-term clinical activity in a substantial fraction of FL patients in need of therapy
One and two dimensional analysis of 3pi correlations measured in Pb+Pb interactions
3pi- correlations from Pb+Pb collisions at 158 GeV/c per nucleon are
presented as measured by the focusing spectrometer of the NA44 experiment at
CERN. The three-body effect is found to be stronger for PbPb than for SPb. The
two-dimensional three-particle correlation function is also measured and the
longitudinal extension of the source is larger than the transverse extension
Search for composite and exotic fermions at LEP 2
A search for unstable heavy fermions with the DELPHI detector at LEP is
reported. Sequential and non-canonical leptons, as well as excited leptons and
quarks, are considered. The data analysed correspond to an integrated
luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV
and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172
GeV and 161 GeV. The search for pair-produced new leptons establishes 95%
confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2,
depending on the channel. The search for singly produced excited leptons and
quarks establishes upper limits on the ratio of the coupling of the excited
fermio
- âŠ