1,429 research outputs found
Can Recent Charge Fluctuations Be a Reliable signal for a QGP at RHIC?
The recent papers of Jeon and Koch [1] and Asakawa, Heinz, and Muller [2]
argue that the event by event fluctuations of the ratio of the positively
charged and negatively charged pions provide a distinct signal for a QGP at
RHIC/LHC due to differences in those from the QGP phase and the Hadron Gas
Phase.In this paper we point out that aside from the questionability of the
many assumptions in the treatment used,even following their approach there are
other effects not considered, e.g. color charge fluctuations, which could
significantly or even completely wash out the proposed signal.Therefore lack of
observation of these charge fluctuation signals cannot lead one to conclude
that a QGP is not formed at RHIC. A general discussion of experimental
requirements for observation of such signals(if they exist),annd how to
interpret them is included.Comment: 9 pages and 2 Fig
The Centrality Dependence of the Parton Bubble Model for high energy heavy ion collisions and fireball surface substructure at RHIC
In an earlier paper we developed a QCD inspired theoretical parton bubble
model (PBM) for RHIC/LHC. The PBM quantitatively agreed with the strong charged
particle pair correlations observed by the STAR collaboration at RHIC in the
highest energy Au + Au central collisions, and also agreed with the Hanbury
Brown and Twiss (HBT) observed small final state source size approximately 2f
radii in the transverse momentum range above 0.8 GeV/c. The model assumed a
substructure of a ring of localized adjoining 2f radius bubbles(gluonic hot
spots) perpendicular to the collider beam direction, centered on the beam, at
mid-rapidity and located on the expanding fireball surface of the Au + Au
collisions. In this paper we extend the model (PBME) to include the changing
development of bubbles with centrality from the most central region where
bubbles are very important to the most peripheral where the bubbles are gone.
Energy density is found to be related to bubble formation and as centrality
decreases the maximum energy density and bubbles shift from symmetry around the
beam axis to the reaction plane region causing a strong correlation of bubble
formation with elliptic flow. We obtained reasonably quantitative agreement
(within a few percent of the total correlations) with a new precision RHIC
experiment which extended the centrality region investigated to the range 0-80%
(most central to most peripheral). The characteristics and behavior of the
bubbles imply they represent a significant substructure formed on the surface
of the fireball at kinetic freezeoutComment: ACCEPTED for publication in Phys. Rev. C. minor referee changes.20
pages, 12 figures, 3 table
Evidence for a 4th state related to the three JPC = 2++, pi- p -> phi phi n states explainable by 2++ Glueball production
Four separate experiments, observing the OZI forbidden disconnected reaction
pi- p -> phi phi n with increasing statistics were consistent. These
experiments very selectively completely broke down the OZI suppression by 3 phi
phi resonances with IG JPC = 0+ 2++ in the observed mass region 2.038 to 2.600
GeV. The only viable proposed explanation has been that the IG JPC = 0+ 2++
Glueball expected in this mass region caused the hard glue in the disconnection
to resonate and very selectively breakdown the OZI suppression for its quantum
numbers only. Recently a p p central production spin analysis found the
f2(1950) had a dominant decay mode f2(1270) pi pi. We consider if it is related
to the phi phi resonances, and find that it likely is.Comment: 9 pages, 3 figure
Recommended from our members
Multiparticle magnetic spectrometer with dE/dx and TRD particle identification
Recent advances in detector development by BNL, CCNY and other groups have made possible new designs of fast high resolution large effective solid angle magnetic multiparticle spectrometers with excellent particle tracking, momentum measurement, and identification capability. These new spectrometers are relatively compact and relatively low cost electronics have been developed for them. Thus the cost is relatively low. These techniques are applied here primarily for design of spectrometers for low p/sub t/ and other physics (at moderate and even high p/sub t/) in the ISABELLE small angle hall. However, one should keep in mind that these techniques can be utilized in many other applications
Production in Au+Au and pp Collisions at = 200GeV at STAR
Mid-rapidity and are
measured in Au+Au and pp collisions at =200GeV using the STAR
detector at RHIC. The mass is systematically shifted at small
transverse momentum for both Au+Au and pp collisions. The
transverse mass spectra are measured in Au+Au collisions at different
centralities and in pp collisions. The mean transverse momentum
as a function of the collision centrality is compared to those of identified
, and . The and ratios are
compared to measurements in A+A, , , collisions at
various colliding energies. The physics implications of these measurements are
also discussed.Comment: 6 pages, 4 figures, proceedings of Strange Quarks in Matter
(SQM2003), Atlantic Beach, USA, to be published in J. Phys.
Observing Spontaneous Strong Parity Violation in Heavy-Ion Collisions
We discuss the problem of observing spontaneous parity and CP violation in
collision systems. We discuss and propose observables which may be used in
heavy-ion collisions to observe such violations, as well as event-by-event
methods to analyze the data. Finally, we discuss simple monte-carlo models of
these CP violating effects which we have used to develop our techniques and
from which we derive rough estimates of sensitivities to signals which may be
seen at RHIC
On Deusons or Deuteronlike Meson-Meson Bound States
The systematics of deuteronlike two-meson bound states, {\it deusons}, is
discussed. Previous arguments that many of the present non- states are
such states are elaborated including, in particular, the tensor potential. For
pseudoscalar states the important observation is made that the centrifugal
barrier from the P-wave can be overcome by the and terms of the
tensor potential. In the heavy meson sector one-pion exchange alone is strong
enough to form at least deuteron-like and composites
bound by approximately 50 MeV, while and states are
expected near the threshold.Comment: Invited talk at the Hadron93 International Conf. on Hadron
Spectroscopy, Como, Italy 22.-25.6. 1993. 5 pages in LATEX HU-SEFT R 1993-13
Palliative care interventions for pediatric surgical patients: a systematic review.
Introduction
There is a growing body of evidence that pediatric palli- ative care increases patient quality of life and parent sat- isfaction. Furthermore, the scope of palliative care con- tinues to expand to include complex care and coordina- tion for chronically ill children who are not necessarily approaching end of life. Many ill children with palliative needs interact with surgical providers and teams. Little is known about the utilization or efficacy of palliative care referrals for pediatric surgical patients.
Material and Methods
To better understand the potential need for palliative care as well as barriers to accessing care among this vulnera- ble population, we performed a systematic review of Pub- Med, EMBASE, and Cinhal for relevant literature pub- lished from January 1, 2008 to March 1, 2018.
Results
10 articles met inclusion criteria. No high-quality studies were identified.
Conclusion
The limited available evidence suggests an unmet need
for pediatric palliative care. Barriers to access were iden- tified including lack of provider palliative care education, and reluctance of the primary team to refer patients to palliative care. Further study is warranted to better guide the use of palliative care for pediatric surgical patients
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