Vladas Tvaskis

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The Q(weak) experiment has measured the parity-violating asymmetry in ep elastic scattering at Q(2)=0.025(GeV/c)(2), employing 145 μA of 89% longitudinally polarized electrons on a 34.4 cm long liquid hydrogen target at Jefferson Lab. The results of the experiment's commissioning run, constituting approximately 4% of the data collected in the experiment,(More)
We propose to make definitive measurements of the deuteron spin structure function g d 1 /F d 1 in the deep-inelastic kinematics accessible with a 6 GeV beam at JLab. The principal goal is to provide the low Q 2 anchor points for NLO pQCD plus higher twist fits to g d 1 /F d 1 , which is particularly sensitive to ∆G(x) (the polarized gluon density of the(More)
  • J Arrington, D F Spokesperson, K Geesaman, R Hafidi, D H Holt, P E Potterveld +42 others
  • 2006
Inclusive scattering from nuclei at x > 1 is sensitive to the distribution of high momentum nucleons at low Q 2 values, and high momentum quarks at large Q 2 values. Large x data at 4 and 6 GeV are dominated by quasielastic and resonance production from high-momentum nucleons. With the 11 GeV beam, we propose to make measurements in the DIS region and(More)
We propose to measure the A(e,e'p) proton knockout and the A(e,e'π +) pion electroproduction cross sections to extract the proton and the pion nuclear transparencies in the nuclear medium. We restrict the proton transparency measurements to the 12 C nucleus with additional 1 H measurements (to determine the elementary process), over the range Q 2 = 8-16(More)
The study of exclusive π(±) electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio RL=σL(π-)/σL(π+) is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from(More)
We report on the first measurement of the F(2) structure function of the neutron from the semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to ≲100 MeV/c and their angles to ≳100° relative to the momentum transfer allows an interpretation of(More)
We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations(More)
We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x>1, which is sensitive to short-range contributions to the nuclear wave function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees(More)
The charged pion form factor, F π (Q 2), is an important quantity that can be used to advance our knowledge of hadronic structure. However, the extraction of F π from data requires a model of the 1 H(e, e π +)n reaction and thus is inherently model dependent. Therefore, a detailed description of the extraction of the charged pion form factor from(More)
Acknowledgements First and foremost I want to thank God and my lord and savior Jesus Christ. A great mantra that I've learned in church, from our pastor, Bob Mosely, is 'no one is perfect, everyone is welcome, anything is possible'. I firmly believe in this and have seen this continuously. I cannot express enough appreciation for my advisor, Ed Hungerford.(More)