4,887 research outputs found
Thermal Recombination: Beyond the Valence Quark Approximation
Quark counting rules derived from recombination models agree well with data
on hadron production at intermediate transverse momenta in relativistic
heavy-ion collisions. They convey a simple picture of hadrons consisting only
of valence quarks. We discuss the inclusion of higher Fock states that add sea
quarks and gluons to the hadron structure. We show that, when recombination
occurs from a thermal medium, hadron spectra remain unaffected by the inclusion
of higher Fock states. However, the quark number scaling for elliptic flow is
somewhat affected. We discuss the implications for our understanding of data
from the Relativistic Heavy Ion Collider.Comment: 5 pages, 5 figure
Hadronization of Dense Partonic Matter
The parton recombination model has turned out to be a valuable tool to
describe hadronization in high energy heavy ion collisions. I review the model
and revisit recent progress in our understanding of hadron correlations. I also
discuss higher Fock states in the hadrons, possible violations of the elliptic
flow scaling and recombination effects in more dilute systems.Comment: 8 pages, 4 figures; plenary talk delivered at SQM 2006, to appear in
J. Phys.
Correlations in the Parton Recombination Model
We describe how parton recombination can address the recent measurement of
dynamical jet-like two particle correlations. In addition we discuss the
possible effect realistic light-cone wave-functions including higher
Fock-states may have on the well-known elliptic flow valence-quark number
scaling law.Comment: 4 pages, two figures, proceedings of the 18th International
Conference on Ultrarelativistic Nucleus-Nucleus Collisions: Quark Matter 2005
(QM 2005), Budapest, Hungary, 4-9 Aug 200
Finite hadronization time and unitarity in quark recombination model
The effect of finite hadronization time is considered in the recombination
model, and it is shown that the hadron multiplicity turns out to be
proportional to the initial quark density and unitarity is conserved in the
model. The baryon to meson ratio increases rapidly with the initial quark
density due to competition among different channels.Comment: 4 pages in RevTeX, 3 eps figures, to appear in J. Phys.G as a lette
Pregnancies complicated by maternal osteogenesis imperfecta type III: a case report and review of literature.
The restrictive lung disease can be exacerbated by growing fundus in women with osteogenesis imperfecta type III. Regional anesthesia can be performed in these women. Mode of delivery for women with osteogenesis imperfecta type III is generally cesarean delivery. Neonatal outcomes are complicated due to indicated preterm deliveries
Gender differences in predictors of self-reported physical aggression: exploring theoretically relevant dimensions among adolescents from Santiago, Chile
Research findings remain unclear on whether different factors predict aggression for adolescent
men and women. Given that aggression research is rarely conducted with Latin American
populations, the current study used multiple imputation and linear regression to assess gender
differences in levels and predictors of self-reported physical aggression among a community
sample of young (ages 11 through 17) men (n=504) and women (n = 471) from Santiago, Chile.
Results revealed that adolescent women reported engaging in higher levels of physical aggression
than men. The variables found to be significantly associated with higher levels of reported
aggression—younger age, less family involvement, less parental control, less positive
relationships with caregivers, having more friends who act out and use substances, having fewer
friends committed to learning, presence of dating violence, and more exposure to neighborhood
crime—were not moderated by gender, implying that similar factors are related to aggression in
adolescent men and women from Chile. Implications for prevention and intervention efforts to
address high-risk adolescents and reduce aggression among Chilean youth are discussed.http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC3876925&blobtype=pdfAccepted manuscrip
Correlated Emission of Hadrons from Recombination of Correlated Partons
We discuss different sources of hadron correlations in relativistic heavy ion
collisions. We show that correlations among partons in a quasi-thermal medium
can lead to the correlated emission of hadrons by quark recombination and argue
that this mechanism offers a plausible explanation for the dihadron
correlations in the few GeV/c momentum range observed in Au+Au collisions at
RHIC.Comment: 4 pages, 2 figures; v2: typo on p.4 correcte
Relativistic Langevin Dynamics in Expanding Media
We study the consequences of different realizations of diffusion processes in
relativistic Langevin simulations. We elaborate on the Ito-Stratonovich dilemma
by showing how microscopically calculated transport coefficients as obtained
from a Boltzmann/Fokker-Planck equation can be implemented to lead to an
unambiguous realization of the Langevin process. Pertinent examples within the
pre-point (Ito) and post-point (H\"anggi-Klimontovich) Langevin prescriptions
are worked out explicitly. Deviations from this implementation are shown to
generate variants of the Boltzmann distribution as the stationary (equilibrium)
solutions. Finally, we explicitly verify how the Lorentz invariance of the
Langevin process is maintained in the presence of an expanding medium,
including the case of an "elliptic flow" transmitted to a Brownian test
particle. This is particularly relevant for using heavy-flavor diffusion as a
quantitative tool to diagnose transport properties of QCD matter as created in
ultrarelativistic heavy-ion collisions.Comment: 8 pages, 4 figures; v2: Reference adde
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