.
Jefferson Lab (JLab) 12 GeV energy upgrade provides a golden opportunity to perform precision studies of the transverse spin and transverse-momentum-dependent structure in the valence quark region ...for both the proton and the neutron. In this paper, we focus our discussion on a recently approved experiment on the neutron as an example of the precision studies planned at JLab. The new experiment will perform precision measurements of target Single-Spin Asymmetries (SSA) from semi-inclusive electro-production of charged pions from a 40 cm long transversely polarized
3
He target in deep-inelastic-scattering kinematics using 11 and 8.8 GeV electron beams. This new coincidence experiment in Hall A will employ a newly proposed solenoid spectrometer (SoLID). The large acceptance spectrometer and the high polarized luminosity will provide precise 4D (
x
,
z
, P
T
and Q
2
) data on the Collins, Sivers, and pretzelosity asymmetries for the neutron through the azimuthal angular dependence. The full 2
azimuthal angular coverage in the lab is essential in controlling the systematic uncertainties. The results from this experiment, when combined with the proton Collins asymmetry measurement and the Collins fragmentation function determined from the e
+
e
-
collision data, will allow for a quark flavor separation in order to achieve a determination of the tensor charge of the d quark to a 10% accuracy. The extracted Sivers and pretzelosity asymmetries will provide important information to understand the correlations between the quark orbital angular momentum and the nucleon spin and between the quark spin and nucleon spin.
A novel proposal of using polarized atomic hydrogen gas, stored in an ultracold magnetic trap, as the target for electron-beam polarimetry based on Moller scattering is discussed. Such a target of ...practically 100% polarized electrons could provide a superb systematic accuracy of about 0.5% for beam polarization measurements. Feasibility studies for the CEBAF electron beam have been performed.
We summarize the ongoing scientific program of the 12 GeV Continuous Electron Beam Accelerator Facility (CEBAF) and give an outlook into future opportunities. The program addresses important topics ...in nuclear, hadronic, and electroweak physics, including nuclear femtography, meson and baryon spectroscopy, quarks and gluons in nuclei, precision tests of the standard model and dark sector searches. Potential upgrades of CEBAF and their impact on scientific reach are discussed, such as higher luminosity, the addition of polarized and unpolarized positron beams, and doubling the beam energy.
The results of experiments concerning the study of cavitational mechanism of liquid failure in a wide range of shock loading are presented in this paper. Free surface velocity of liquids and velocity ...spectrum of particles and jets were recorded using PDV method 1, their size was also determined. The value of spall strength of distilled water was defined.
Experimental results on the study of spallation and cavitation from solid (Cu and Pb) and liquefied Pb are presented. Pb ejecta transporting in air is also studied with a multi-probe laser ...interferometry method that is applied to detect and quantify the particle cloud velocity and surface fragmentation. The laser diagnostic is designed to probe ejecta velocity- and dispersion-profiles within ejecta fragment clouds, and spallation structures.
We consider photoproduction of ω mesons off complex nuclei to study interactions of transversely and longitudinally polarized vector mesons with nucleons. Whereas the total cross section for ...interactions of the transversely polarized vector mesons with nucleons σT = σ(VTN) can be obtained from coherent photoproduction, measurements of vector meson photoproduction in the incoherent region provide a unique opportunity to extract the not-yet-measured total cross section for longitudinally polarized mesons σL = σ(VLN). The predictions for the latter strongly depend on the theoretical approaches. Furthermore, this work is stimulated by the construction of the new experiment GlueX at Jefferson Lab, designed to study the photoproduction of mesons in a large beam energy range up to 12 GeV.
We report experimental results on studies of the interactions between various gases and the mass ejected from a shock accelerated surface. While such studies have been conducted in the past, data on ...such dynamic gas-ejecta interactions are incomplete. Therefore, along these lines, in the present work new comparative results are given concerning mass ejection from free surfaces of lead interfaced with vacuum or gas. The comparisons are made for the ejecta mass as a function of the surface roughness, the peak shockwave loading stress (amplitude)
P
S
, and the release phase (state) of the post-shock metal.
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