98 research outputs found
Proučavanje kratkodosežne dinamike u maločestičnim sustavima
I present the case for studying the nature of short-range internucleon interactions with electron-scattering experiments on few-body nuclear targets. I first review what electron-scattering studies have unearthed about the nature of the interactions between nucleons in nuclei at small separation. Special consideration is given to a couple of recent experiments. The results essentially serve to construct a roadmap for future studies in this area. The related experimental program at Jefferson Lab is presented, along with suggestions for future theoretical work.Izlaže se važnost proučavanja kratkodosežnih međunukleonskih sila mjerenjem elektronskog raspršenja u maločestičnim jezgrama. Prvo se raspravlja što su otkrila mjerenja elektronskog raspršenja o prirodi sila među nukleonima u jezgrama na malim udaljenostima. Posebna se pažnja daje dvama nedavnim mjerenjima. Rezultati služe kao putokaz budućim proučavanjima. Opisuje se odgovarajući program u Jeffersonovom laboratoriju i predlaže budući teorijski rad
Proučavanje kratkodosežne dinamike u maločestičnim sustavima
I present the case for studying the nature of short-range internucleon interactions with electron-scattering experiments on few-body nuclear targets. I first review what electron-scattering studies have unearthed about the nature of the interactions between nucleons in nuclei at small separation. Special consideration is given to a couple of recent experiments. The results essentially serve to construct a roadmap for future studies in this area. The related experimental program at Jefferson Lab is presented, along with suggestions for future theoretical work.Izlaže se važnost proučavanja kratkodosežnih međunukleonskih sila mjerenjem elektronskog raspršenja u maločestičnim jezgrama. Prvo se raspravlja što su otkrila mjerenja elektronskog raspršenja o prirodi sila među nukleonima u jezgrama na malim udaljenostima. Posebna se pažnja daje dvama nedavnim mjerenjima. Rezultati služe kao putokaz budućim proučavanjima. Opisuje se odgovarajući program u Jeffersonovom laboratoriju i predlaže budući teorijski rad
HEP Applications Evaluation of the EDG Testbed and Middleware
Workpackage 8 of the European Datagrid project was formed in January 2001
with representatives from the four LHC experiments, and with experiment
independent people from five of the six main EDG partners. In September 2002
WP8 was strengthened by the addition of effort from BaBar and D0. The original
mandate of WP8 was, following the definition of short- and long-term
requirements, to port experiment software to the EDG middleware and testbed
environment. A major additional activity has been testing the basic
functionality and performance of this environment. This paper reviews
experiences and evaluations in the areas of job submission, data management,
mass storage handling, information systems and monitoring. It also comments on
the problems of remote debugging, the portability of code, and scaling problems
with increasing numbers of jobs, sites and nodes. Reference is made to the
pioneeering work of Atlas and CMS in integrating the use of the EDG Testbed
into their data challenges. A forward look is made to essential software
developments within EDG and to the necessary cooperation between EDG and LCG
for the LCG prototype due in mid 2003.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
Conference (CHEP03), La Jolla, CA, USA, March 2003, 7 pages. PSN THCT00
Measurement of Rlt and Atl in the 4He(e,e'p)3H Reaction at pmiss of 130-300 MeV/c
We have measured the 4He(e,e'p)3H reaction at missing momenta of 130-300
MeV/c using the three-spectrometer facility at the Mainz microtron MAMI. Data
were taken in perpendicular kinematics to allow us to determine the response
function Rlt and the asymmetry term Atl. The data are compared to both
relativistic and non-relativistic calculations.Comment: To be published in the European Physical Journal
High-precision Studies of the He(e,ep) Reaction at the Quasielastic Peak
Precision studies of the reaction He(e,ep) using the
three-spectrometer facility at the Mainz microtron MAMI are presented. All data
are for quasielastic kinematics at MeV/c. Absolute cross
sections were measured at three electron kinematics. For the measured missing
momenta range from 10 to 165 MeV/c, no strength is observed for missing
energies higher than 20 MeV. Distorted momentum distributions were extracted
for the two-body breakup and the continuum. The longitudinal and transverse
behavior was studied by measuring the cross section for three photon
polarizations. The longitudinal and transverse nature of the cross sections is
well described by a currently accepted and widely used prescription of the
off-shell electron-nucleon cross-section. The results are compared to modern
three-body calculations and to previous data.Comment: 4 pages, 3 figures. Submitted for publication in Phys. Rev. Let
Relativistic effects and two-body currents in using out-of-plane detection
Measurements of the reaction were performed
using an 800-MeV polarized electron beam at the MIT-Bates Linear Accelerator
and with the out-of-plane magnetic spectrometers (OOPS). The
longitudinal-transverse, and , and the
transverse-transverse, , interference responses at a missing momentum
of 210 MeV/c were simultaneously extracted in the dip region at Q=0.15
(GeV/c). On comparison to models of deuteron electrodisintegration, the
data clearly reveal strong effects of relativity and final-state interactions,
and the importance of the two-body meson-exchange currents and isobar
configurations. We demonstrate that these effects can be disentangled and
studied by extracting the interference response functions using the novel
out-of-plane technique.Comment: 4 pages, 4 figures, and submitted to PRL for publicatio
The reaction dynamics of the 16O(e,e'p) cross section at high missing energies
We measured the cross section and response functions (R_L, R_T, and R_LT) for
the 16O(e,e'p) reaction in quasielastic kinematics for missing energies 25 <=
E_miss <= 120 MeV at various missing momenta P_miss <= 340 MeV/c. For 25 <
E_miss < 50 MeV and P_miss \approx 60 MeV/c, the reaction is dominated by
single-nucleon knockout from the 1s1/2-state. At larger P_miss, the
single-particle aspects are increasingly masked by more complicated processes.
For E_miss > 60 MeV and P_miss > 200 MeV/c, the cross section is relatively
constant. Calculations which include contributions from pion exchange currents,
isobar currents and short-range correlations account for the shape and the
transversity but only for half of the magnitude of the measured cross section.Comment: 6 pages, 4 figures, submitted to Phys Rev Lett, formatting error
fixe
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