97513211
SPIN STRUCTURE FUNCTIONS OF THE DEUTERON
121886810
Experimental Results in DIS, SIDIS and DES from Jefferson Lab
Jefferson Lab’s electron accelerator in its present incarnation, with a maximum beam energy slightly above 6 GeV, has already enabled a large number of experiments expanding our knowledge of nucleon and nuclear structure (especially in Deep Inelastic Scattering—DIS—at moderately high x, and in the resonance region). Several pioneering experiments have yielded first results on Deeply Virtual Compton Scattering (DVCS) and other Deep Exclusive Processes (DES), and the exploration of the rich landscape of transverse momentum‐dependent (TMD) structure functions using Semi‐Inclusive electron scattering (SIDIS) has begun. With the upgrade of CEBAF to 12 GeV now underway, a significantly larger kinematic space will become available. The 12 GeV program taking shape will complete a detailed mapping of inclusive, TMD and generalized distribution functions for quarks, antiquarks and gluons in the valence region and beyond.
36168504
Measurements of cross sections relevant to gamma -ray line astronomy.
49585998
Parity violation in proton-proton scattering at 13.6 MeV
Abstract Parity nonconservation in proton-proton scattering has been studied by measuring the angle-integrated longitudinal analyzing power A z . We found A z (13.6 MeV)=(−1.5±0.5)×10 −7 . The error includes uncertainties due to statistics and corrections, as well as upper limits on systematic effects. The experimental result is discussed with respect to recent theoretical calculations.
55178975
Measurement of the x- and Q(2)-dependence of the asymmetry A(1) on the nucleon
We report results for the virtual photon asymmetry A{sub 1} on the nucleon from new Jefferson Lab measurements. The experiment, which used the CEBAF Large Acceptance Spectrometer and longitudinally polarized proton ({sup 15}NH{sub 3}) and deuteron ({sup 15}ND{sub 3}) targets, collected data with a longitudinally polarized electron beam at energies between 1.6 GeV and 5.7 GeV. In the present paper, we concentrate on our results for A{sub 1}(x,Q{sup 2}) and the related ratio g{sub 1}/F{sub 1}(x,Q{sup 2}) in the resonance and the deep inelastic regions for our lowest and highest beam energies, covering a range in momentum transfer Q{sup 2} from 0.05 to 5.0 GeV{sup 2} and in final-state invariant mass W up to about 3 GeV. Our data show detailed structure in the resonance region, which leads to a strong Q{sup 2}--dependence of A{sub 1}(x,Q{sup 2}) for W below 2 GeV. At higher W, a smooth approach to the scaling limit, established by earlier experiments, can be seen, but A{sub 1}(x,Q{sup 2}) is not strictly Q{sup 2}--independent. We add significantly to the world data set at high x, up to x = 0.6. Our data exceed the SU(6)-symmetric quark model expectation for both the proton and the deuteron whilemore » being consistent with a negative d-quark polarization up to our highest x. This data set should improve next-to-leading order (NLO) pQCD fits of the parton polarization distributions.« less
120340258
A polarized target for the CLAS detector
Abstract We describe the design, construction, and performance of a polarized solid target for use in electron scattering experiments with the CEBAF Large Acceptance Spectrometer. Protons and deuterons are continuously polarized by microwave-induced spin–flip transitions at 1 K and 5 T . The target operated successfully during two cycles in 1998 and 2000, providing proton and deuteron polarizations as high as 96% and 46%, respectively. The unique features of the target which permit its use inside a 4π spectrometer are stressed. Comparison is made between the target polarization measured by the traditional method of NMR and by electron elastic scattering.
8682177
First Beam Test Characterisation of a 3D-stc Silicon Short Strip Detector
The planned upgrade to the CERN Large Hadron Collider (LHC), the Super-LHC (sLHC) will increase its luminosity by a factor of ten. This necessitates the development of silicon tracking detectors that are significantly more radiation resistant than the ones employed at the LHC. Currently, new detector technologies are being developed to cope with the increased levels of radiation damage at the sLHC. A possible radiation hard option for silicon short strip devices (SSD) in the inner layers of sLHC trackers are 3-D detectors with rows of columnar electrodes processed into the bulk material. These are joined together to form strips. While the excellent radiation hardness of this design has been proven before in lab experiments, a 3-D SSD prototype has now been investigated for the first time in a beam test with pions of a nominal energy of 180 GeV. The use of analog LHC-speed electronics, a beam telescope and time-resolved measurements allowed for detailed studies of the signal behavior on the hit strip and its neighboring strips. Charge collection and efficiency were as well measured with respect to time and point of incidence of the beam particles on the detector. The results of these measurements are presented in this paper.
41938556
Short Strips for the sLHC: A P-Type Silicon Microstrip Detector in 3-D Technology
The luminosity upgrade of the Large Hadron Collider (LHC), the sLHC, will constitute an extremely challenging radiation environment for tracking detectors. With respect to the LHC, large improvements in radiation hardness are required. In this paper, we investigated the expected radiation hardness of the 3-D-design, where rows of 3-D-columns are etched in substrate material and joined together to form strips. To investigate the feasibility of 3-D silicon strip detectors (SSD) for the sLHC, we have built prototype modules using 3-D single type column (3-D-STC) strip detectors with short strips and front-end electronics from the present ATLAS SemiConductor Tracker (SCT). The modules were tested with a beta source setup before and after irradiation to sLHC fluences with 26 MeV protons. We report on the performance of these 3-D-modules, compare it to the results prior to irradiation, and draw conclusions about options for using 3-D SSD detectors for tracking at the sLHC.
25295548
Short strips for the SLHC: A P-Type Silicon microstrip detector in 3D-technology
The luminosity upgrade of the Large Hadron Collider (LHC), the sLHC, will constitute an extremely challenging radiation environment for tracking detectors. With respect to the LHC, massive improvements in radiation hardness are required. In this paper we investigate the superior radiation hardness of the 3D-design, where rows of 3D-columns are etched in substrate material and joined together to form strips. To demonstrate the feasibility of 3D silicon strip detectors (SSDs) for the sLHC, we have built prototype modules using 3D single type column (3D-STC) strip detectors with short strips and front-end electronics from the present ATLAS SemiConductor Tracker (SCT). The modules were tested with a beta source setup before and after irradiation to sLHC fluences with 26 MeV protons. We report on the performance of these 3D-modules, compare it to the results prior to irradiation, and draw conclusions about options for using 3D SSDs for tracking at the sLHC.