82 research outputs found
Antiproton Production in Collisions at AGS Energies
Inclusive and semi-inclusive measurements are presented for antiproton
() production in proton-nucleus collisions at the AGS. The inclusive
yields per event increase strongly with increasing beam energy and decrease
slightly with increasing target mass. The yield in 17.5 GeV/c p+Au
collisions decreases with grey track multiplicity, , for ,
consistent with annihilation within the target nucleus. The relationship
between and the number of scatterings of the proton in the nucleus is
used to estimate the annihilation cross section in the nuclear
medium. The resulting cross section is at least a factor of five smaller than
the free annihilation cross section when assuming a small or
negligible formation time. Only with a long formation time can the data be
described with the free annihilation cross section.Comment: 8 pages, 6 figure
Inclusive Soft Pion Production from 12.3 and 17.5 GeV/c Protons on Be, Cu and Au
Differential cross-sections are presented for the inclusive production of
charged pions in the momentum range 0.1 to 1.2 GeV/c in interactions of 12.3
and 17.5 GeV/c protons with Be, Cu, and Au targets. The measurements were made
by Experiment 910 at the Alternating Gradient Synchrotron in Brookhaven
National Laboratory. The cross-sections are presented as a function of pion
total momentum and production polar angle with respect to the beam.Comment: 14 pages, 8 figure
Muon Colliders
Muon Colliders have unique technical and physics advantages and disadvantages
when compared with both hadron and electron machines. They should thus be
regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high
luminosity \mumu colliders, and of a 0.5 TeV lower luminosity demonstration
machine. We discuss the various systems in such muon colliders, starting from
the proton accelerator needed to generate the muons and proceeding through muon
cooling, acceleration and storage in a collider ring. Problems of detector
background are also discussed.Comment: 28 pages, with 12 postscript figures. To be published Proceedings of
the 9th Advanced ICFA Beam Dynamics Workshop, AIP Pres
Status of Muon Collider Research and Development and Future Plans
The status of the research on muon colliders is discussed and plans are
outlined for future theoretical and experimental studies. Besides continued
work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy
collider, many studies are now concentrating on a machine near 0.1 TeV (CoM)
that could be a factory for the s-channel production of Higgs particles. We
discuss the research on the various components in such muon colliders, starting
from the proton accelerator needed to generate pions from a heavy-Z target and
proceeding through the phase rotation and decay ()
channel, muon cooling, acceleration, storage in a collider ring and the
collider detector. We also present theoretical and experimental R & D plans for
the next several years that should lead to a better understanding of the design
and feasibility issues for all of the components. This report is an update of
the progress on the R & D since the Feasibility Study of Muon Colliders
presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A.
Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics
(Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics,
Accelerators and Beam
Semi-Inclusive Lambda and Kshort Production in p-Au Collisions at 17.5 GeV/c
The first detailed measurements of the centrality dependence of strangeness
production in p-A collisions are presented. Lambda and Kshort dn/dy
distributions from 17.5 GeV/c p-Au collisions are shown as a function of "grey"
track multiplicity and the estimated number of collisions, nu, made by the
proton. The nu dependence of the Lambda yield deviates from a scaling of p-p
data by the number of participants, increasing faster than this scaling for
nu<=5 and saturating for larger nu. A slower growth in Kshort multiplicity with
nu is observed, consistent with a weaker nu dependence of K-Kbar production
than Y-K production.Comment: 5 pages, 3 figures, formatted with RevTex, current version has
enlarged figure catpion
Physics at a Neutrino Factory
In response to the growing interest in building a Neutrino Factory to produce
high intensity beams of electron- and muon-neutrinos and antineutrinos, in
October 1999 the Fermilab Directorate initiated two six-month studies. The
first study, organized by N. Holtkamp and D. Finley, was to investigate the
technical feasibility of an intense neutrino source based on a muon storage
ring. This design study has produced a report in which the basic conclusion is
that a Neutrino Factory is technically feasible, although it requires an
aggressive R&D program. The second study, which is the subject of this report,
was to explore the physics potential of a Neutrino Factory as a function of the
muon beam energy and intensity, and for oscillation physics, the potential as a
function of baseline.Comment: 133 pages, 64 figures. Report to the Fermilab Directorate. Available
from http://www.fnal.gov/projects/muon_collider/ This version fixes some
printing problem
Molecular Networks in FGF Signaling: Flotillin-1 and Cbl-Associated Protein Compete for the Binding to Fibroblast Growth Factor Receptor Substrate 2
Fibroblast growth factor receptor substrate 2 (FRS2α) is a signaling adaptor protein that regulates downstream signaling of many receptor tyrosine kinases. During signal transduction, FRS2 can be both tyrosine and threonine phosphorylated and forms signaling complexes with other adaptor proteins and tyrosine phosphatases. We have here identified flotillin-1 and the cbl-associated protein/ponsin (CAP) as novel interaction partners of FRS2. Flotillin-1 binds to the phosphotyrosine binding domain (PTB) of FRS2 and competes for the binding with the fibroblast growth factor receptor. Flotillin-1 knockdown results in increased Tyr phosphorylation of FRS2, in line with the inhibition of ERK activity in the absence of flotillin-1. CAP directly interacts with FRS2 by means of its sorbin homology (SoHo) domain, which has previously been shown to interact with flotillin-1. In addition, the third SH3 domain in CAP binds to FRS2. Due to the overlapping binding domains, CAP and flotillin-1 appear to compete for the binding to FRS2. Thus, our results reveal a novel signaling network containing FRS2, CAP and flotillin-1, whose successive interactions are most likely required to regulate receptor tyrosine kinase signaling, especially the mitogen activated protein kinase pathway
- …