Parity-Violating Electron Scattering from (4)He and the Strange Electric Form Factor of the Nucleon

We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 4He at an average scattering angle ⟨θlab⟩=5.7° and a four-momentum transfer Q2=0.091  GeV2. From these data, for the first time, the strange electric form factor of the nucleon GEs can be isolated. The measured asymmetry of APV=(6.72±0.84(stat)±0.21(syst))×10-6 yields a value ofGEs=-0.038±0.042(stat)±0.010(syst), consistent with zero

Deeply Virtual Compton Scattering off the Neutron

The present experiment exploits the interference between the deeply virtual Compton scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D(e⃗,e′γ)X cross section measured at Q2=1.9  GeV2 and xB=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to Eq, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced

Investigation of Proton-Proton Short-Range Correlations via the (12)C(e,e′pp) Reaction

We investigated simultaneously the 12C(e,e′p) and 12C(e,e′pp) reactions at Q2=2  (GeV/c)2, xB=1.2, and in an (e, e′p) missing-momentum range from 300 to 600  MeV/c. At these kinematics, with a missing momentum greater than the Fermi momentum of nucleons in a nucleus and far from the delta excitation, short-range nucleon-nucleon correlations are predicted to dominate the reaction. For (9.5±2)% of the 12C(e,e′p) events, a recoiling partner proton was observed back-to-back to the 12C(e,e′p) missing-momentum vector, an experimental signature of correlations

High-Resolution Spectroscopy of Λ(16)N by Electroproduction

An experimental study of the 16O(e,e′K+)Λ16N reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e′K+)Λ,Σ0 exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76±0.16  MeV was obtained for Λ16N with better precision than previous measurements on the mirror hypernucleus Λ16O. Precise energies have been determined for peaks arising from a Λ in s and p orbits coupled to the p1/2 and p3/2 hole states of the 15N core nucleus

Exclusive Neutral Pion Electroproduction in the Deeply Virtual Regime

We present measurements of the ep→epπ0 cross section extracted at two values of four-momentum transfer Q2=1.9 GeV2 and Q2=2.3 GeV2 at Jefferson Lab Hall A. The kinematic range allows one to study the evolution of the extracted cross section as a function of Q2 and W. Results are confronted with Regge-inspired calculations and GPD predictions. An intepretation of our data within the framework of semi-inclusive deep inelastic scattering is also discussed

Single Spin Asymmetries in Charged Pion Production from Semi-Inclusive Deep Inelastic Scattering on a Transversely Polarized (3)He Target at Q(2)=1.4–2.7 GeV(2)

We report the first measurement of target single spin asymmetries in the semi-inclusive 3He(e,e′π±)X reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.1622. The Collins and Sivers moments were extracted from the azimuthal angular dependence of the measured asymmetries. The π± Collins moments for 3He are consistent with zero, except for the π+ moment at x=0.35, which deviates from zero by 2.3σ. While the π- Sivers moments are consistent with zero, the π+ Sivers moments favor negative values. The neutron results were extracted using the nucleon effective polarization and measured cross section ratios of proton to 3He, and are largely consistent with the predictions of phenomenological fits and quark model calculations

Beam-Target Double-Spin Asymmetry A(LT) in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized (3)He Target at 1.4

We report the first measurement of the double-spin asymmetry ALT for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized 3He target. The kinematics focused on the valence quark region, 0.1622. The corresponding neutron ALT asymmetries were extracted from the measured 3He asymmetries and proton over 3He cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function g1Tq and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for π- production on 3He and the neutron, while our π+ asymmetries are consistent with zero

The Hybrid Hanger: A lightweight, portable hang-on tree stand with high durability and ease of use.

The Hybrid Hanger is a fully carbon fiber-epoxy composite hang-on tree stand. This 12-pound tree stand design allows a hunter to carry the stand further without fatiguing, which is perfect for public land hunters. In order to support the weight of a person and the harshness of hunting environments, the Hybrid Hanger will need to be strong and weather resistant. It has been tested to 600 pounds and the carbon fiber is an improvement upon the current metal stands of today’s market. Other qualities of the Hybrid Hanger that improve upon current tree stands in the market include: noise reduction, corrosion 41 resistance, and the compact and sleek design. The Hybrid Hanger will also be foldable with backpack straps to easily carry on a hunter’s back as they walk to their hunting location.https://openriver.winona.edu/urc2019/1021/thumbnail.jp

Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering

We present the first measurements of the e⃗p→epγ cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q2 dependence (from 1.5 to 2.3  GeV2) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q2. The helicity-independent cross section is also measured at Q2=2.3  GeV2. We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation

But Is It Myopia? Risk Aversion and the Efficiency of Stock-Based Managerial Incentives

This paper points out that stock incentives do not lead to myopia unless they result in more emphasis on the short-term than would occur under an optimal contract. It shows that myopia findings relative to the standard used throughout the literature (first-best efficiency) are often reversed when evaluated relative to the relevant standard of optimal contracting. Results reported by the previous literature to be myopia often in fact have excessive emphasis on the long-term. The paper solves in closed-form for the region in parameter space which gives rise to these reversals and shows that it can be arbitrarily largehttp://deepblue.lib.umich.edu/bitstream/2027.42/49369/5/2008Jan16JCarmel.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/49369/1/Visiting-Carmel.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/49369/4/Visiting-Carmel.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/49369/7/1108_2008Jan16JCarmel.pd