7,023 research outputs found
Trends in multiparticle production and some "predictions" for pp and PbPb collisions at LHC
Based on trends seen at lower energies we "predict" the multiplicities and
pseudorapidity distributions of particle density and elliptic flow that will be
seen in PbPb and pp collisions at the LHC. We argue that, if these predictions
turn out to be correct, either these quantities are insensitive to the state of
matter created in high energy heavy ion collisions or the observed simplicity
and universality of the data must be telling us something profound about the
mechanism of particle production, which to this date is not well understood.Comment: Invited Talk at SQM2007 Conferenc
Kaon and production vs Participants in Nuclear Collisions
Data on kaon and production in nuclear collisions as a function of
centrality are analysed both at AGS and SPS energy range. We compare the
results of several experiments, looking for common trend in `participant
scaling' of production yields. We find a smooth description of scaled kaon and
yields as a function of participant density. We also show a participant
density dependence of kaons and produced in the forward hemisphere for
proton-nucleus collisions.Comment: Proceedings of the International Conference on Strangeness in Quark
Matter, 20-25 July 2000, Berkeley, CA. To appear in Journal of Physics G:
Nuclear and Particle Physic
Where Is Your Farm Today?
The typical farm business is different from most nonfarm businesses. In farming, there\u27s a close interdependence between the farm household and the farm business- they can\u27t be separated into two distinct units as in most other industries
Interdependence between the farm business and the farm household with implications on economic efficiency
In no other industry is the interdependence between the consuming household and the business firm so strong as in agriculture. The farm is a complete economic unit by itself. The business and household units are intertwined in the farm with production and consumption taking place in one central spot. Hence limited resources are allocated between the two in accordance with the preferences of the family. The economic problems of a farm exactly parallel those of a national economy and include the three major areas of choice and decision: (1) the allocation of resources or income between current and future consumption, (2) the allocation of limited resources or income in current production and (3) the distribution of current consumption income between different individuals. In reality, the first decision is largely one of allocation in production over time. Problems of production and consumption allocation at the farm level have received little attention in the general body of economic principIes. In general, the economic principles applicable to the business firm have been developed independently of the consumption unit, and the logic of the consuming unit has been developed independently of the business firm. A more realistic approach for agriculture is to consider production and consumption as interdependent units
Possible glueball production in relativistic heavy-ion collisions
Within a thermal model we estimate possible multiplicities of scalar
glueballs in central Au+Au collisions at AGS, SPS, RHIC and LHC energies. For
the glueball mass in the region 1.5-1.7 GeV, the model predicts on average (per
event) 0.5-1.5 glueballs at RHIC and 1.5-4 glueballs at LHC energies. Possible
enhancement mechanisms are discussed.Comment: 8 pages, 2 figure
Studies of multiplicity in relativistic heavy-ion collisions
In this talk I'll review the present status of charged particle multiplicity
measurements from heavy-ion collisions. The characteristic features of
multiplicity distributions obtained in Au+Au collisions will be discussed in
terms of collision centrality and energy and compared to those of p+p
collisions. Multiplicity measurements of d+Au collisions at 200 GeV
nucleon-nucleon center-of-mass energy will also be discussed. The results will
be compared to various theoretical models and simple scaling properties of the
data will be identified.Comment: "Focus on Multiplicity" Internationsl Workshop on Particle
Multiplicity in Relativistic Heavy Ion Collisions, Bari, Italy, June 17-19,
2003, 16 pages, 15 figure
Silicon Pad Detectors for the PHOBOS Experiment at RHIC
The PHOBOS experiment is well positioned to obtain crucial information about
relativistic heavy ion collisions at RHIC, combining a multiplicity counter
with a multi-particle spectrometer. The multiplicity arrays will measure the
charged particle multiplicity over the full solid angle. The spectrometer will
be able to identify particles at mid-rapidity. The experiment is constructed
almost exclusively of silicon pad detectors. Detectors of nine different types
are configured in the multiplicity and vertex detector (22,000 channels) and
two multi-particle spectrometers (120,000 channels). The overall layout of the
experiment, testing of the silicon sensors and the performance of the detectors
during the engineering run at RHIC in 1999 are discussed.Comment: 7 pages, 7 figures, 1 table, Late
Global polarization of QGP in non-central heavy ion collisions at high energies
Due to the presence of a large orbital angular momentum of the parton system
produced at the early stage of non-central heavy-ion collisions, quarks and
anti-quarks are shown to be polarized in the direction opposite to the reaction
plane which is determined by the impact-parameter and the beam momentum. The
global quark polarization via elastic scattering was first calculated in an
effective static potential model, then using QCD at finite temperature with the
hard-thermal-loop re-summed gluon propagator. The measurable consequences are
discussed. Global hyperon polarization from the hadronization of polarized
quarks are predicted independent of the hadronization scenarios. It has also
been shown that the global polarization of quarks and anti-quarks leads also to
spin alignment of vector mesons. Dedicated measurements at RHIC are underway
and some of the preliminary results are obtained. In this presentation, the
basic idea and main results of global quark polarization are presented. The
direct consequences such as global hyperon polarization and spin alignment are
summarized.Comment: plenary talk at the 19th International Conference on
Ultra-Relativistic Nucleus-Nucleus Collisions (QM2006), Shanghai, China,
November 14-20, 200
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