646 research outputs found
Precise Determination of the Neutron Magnetic Form Factor to Higher
The neutron elastic magnetic form factor has been extracted from
quasielastic scattering from deuterium in the CEBAF Large Acceptance
Spectrometer, CLAS. The kinematic coverage of the measurement is continuous
over a broad range, extending from below 1 to nearly 5 in
four-momentum transfer squared. High precision is achieved by employing a ratio
technique in which most uncertainties cancel, and by a simultaneous in-situ
calibration of the neutron detection efficiency, the largest correction to the
data. Preliminary results are shown with statistical errors only.Comment: Contribution to the proceedings of the Tenth International Conference
on Baryons (2004), to be published in Nuclear Physics, Section
Experimental Studies of Hadronization and Parton Propagation in the Space-Time Domain
Over the past decade, new data have become available from DESY, Jefferson
Lab, Fermilab, and RHIC that connect to parton propagation and hadron
formation. Semi-inclusive DIS on nuclei, the Drell-Yan reaction, and heavy-ion
collisions all bring different kinds of information on parton propagation
within a medium, while the most direct information on hadron formation comes
from the DIS data. Over the next decade one can hope to begin to understand
these data within a unified picture. We briefly survey the most relevant data
and the common elements of the physics picture, then highlight the new
Jefferson Lab data from CLAS, and close with prospects for the future.Comment: 8 pages, 6 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse
Kinematically Complete Measurements of p+p→p+n+(pi+) Near Threshold
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Kinematically Complete Measurements of p+p → p+n+(pi+) Near Threshold
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Report on CE-19: 16-O(p,n)16-F(0-) in the IUCF Cooler
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
An experimental study of the flow-induced noise created by a wall-mounted finite length airfoil
AIAA 2014-3290This paper presents the results of an experimental investigation of the sound produced by flow interaction with a wall-mounted finite length airfoil at low-to-moderate Reynolds number. Acoustic measurements have been taken in an anechoic wind tunnel at a range of Reynolds numbers, angles of attack and for a variety of airfoil aspect ratios (airfoil length to chord ratio) with a single microphone and two perpendicular planar microphone arrays. For comparison, measurements have also been taken with a semi-infinite or two- dimensional airfoil and a half-span airfoil with tip flow but no boundary layer impingement. The experimental data is used to examine changes in wall-mounted finite airfoil noise production as a function of Reynolds number, angle of attack and airfoil aspect ratio. Additionally, the data gives insight into the airfoil noise generation mechanisms and the influence of flow at the airfoil tip and wall junction on noise productionDanielle J. Moreau , Zebb Prime and Con J. Doola
Analyzing Powers for pp → pnπ^+
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Space-time evolution of hadronization
Beside its intrinsic interest for the insights it can give into color
confinement, knowledge of the space-time evolution of hadronization is very
important for correctly interpreting jet-quenching data in heavy ion collisions
and extracting the properties of the produced medium. On the experimental side,
the cleanest environment to study the space-time evolution of hadronization is
semi-inclusive Deeply Inelastic Scattering on nuclear targets. On the
theoretical side, 2 frameworks are presently competing to explain the observed
attenuation of hadron production: quark energy loss (with hadron formation
outside the nucleus) and nuclear absorption (with hadronization starting inside
the nucleus). I discuss recent observables and ideas which will help to
distinguish these 2 mechanisms and to measure the time scales of the
hadronization process.Comment: 6 pages, 4 figures. Based on talks given at "Hot Quarks 2006",
Villasimius, Italy, May 15-20, 2006, and at the "XLIV internataional winter
meeting on nuclear physics", Bormio, Italy, Jan 29 - Feb 5, 2006. To appear
in Eur.Phys.J.
Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab
We present measurements of the differential cross section and Lambda recoil
polarization for the gamma p to K+ Lambda reaction made using the CLAS detector
at Jefferson Lab. These measurements cover the center-of-mass energy range from
1.62 to 2.84 GeV and a wide range of center-of-mass K+ production angles.
Independent analyses were performed using the K+ p pi- and K+ p (missing pi -)
final-state topologies; results from these analyses were found to exhibit good
agreement. These differential cross section measurements show excellent
agreement with previous CLAS and LEPS results and offer increased precision and
a 300 MeV increase in energy coverage. The recoil polarization data agree well
with previous results and offer a large increase in precision and a 500 MeV
extension in energy range. The increased center-of-mass energy range that these
data represent will allow for independent study of non-resonant K+ Lambda
photoproduction mechanisms at all production angles.Comment: 22 pages, 16 figure
Tensor Correlations Measured in 3He(e,e'pp)n
We have measured the 3He(e,e'pp)n reaction at an incident energy of 4.7 GeV
over a wide kinematic range. We identified spectator correlated pp and pn
nucleon pairs using kinematic cuts and measured their relative and total
momentum distributions. This is the first measurement of the ratio of pp to pn
pairs as a function of pair total momentum, . For pair relative
momenta between 0.3 and 0.5 GeV/c, the ratio is very small at low and
rises to approximately 0.5 at large . This shows the dominance of
tensor over central correlations at this relative momentum.Comment: 4 pages, 4 figures, submitted to PR
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