Adiabatic light guide with S-shaped strips.

A light guide is an essential part of many scintillator counters and light collection systems. Our main interest is a light guide for a thin, wide scintillator that has high light transmission while converting the area of the light source to the shape of a photo-detector. We propose a variation of the light guide that avoids a 90° twist of the strips, reduces the length of the light pipe, and reduces the complexity of production.

Novel Measurement of the Neutron Magnetic Form Factor from A=3 Mirror Nuclei.

The electromagnetic form factors of the proton and neutron encode information on the spatial structure of their charge and magnetization distributions. While measurements of the proton are relatively straightforward, the lack of a free neutron target makes measurements of the neutron's electromagnetic structure more challenging and more sensitive to experimental or model-dependent uncertainties. Various experiments have attempted to extract the neutron form factors from scattering from the neutron in deuterium, with different techniques providing different, and sometimes large, systematic uncertainties.

Revealing the short-range structure of the mirror nuclei H and He.

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure, and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements.

Precision Determination of the Neutral Weak Form Factor of ^{48}Ca.

We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{48}Ca. We measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(q=0.8733  fm^{-1})=0.

Deeply Virtual Compton Scattering Cross Section at High Bjorken x_{B}.

We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable x_{B}. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of x_{B}, while systematically including helicity flip amplitudes.

New Measurements of the Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering over a Range of Spin-0 Nuclei.

We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed.

Measurement of the Nucleon F_{2}^{n}/F_{2}^{p} Structure Function Ratio by the Jefferson Lab MARATHON Tritium/Helium-3 Deep Inelastic Scattering Experiment.

The ratio of the nucleon F_{2} structure functions, F_{2}^{n}/F_{2}^{p}, is determined by the MARATHON experiment from measurements of deep inelastic scattering of electrons from ^{3}H and ^{3}He nuclei. The experiment was performed in the Hall A Facility of Jefferson Lab using two high-resolution spectrometers for electron detection, and a cryogenic target system which included a low-activity tritium cell. The data analysis used a novel technique exploiting the mirror symmetry of the two nuclei, which essentially eliminates many theoretical uncertainties in the extraction of the ratio.

Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering.

We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75  (GeV/c)^{2}. Combined with existing data, these provide an improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed.

Deep Exclusive Electroproduction of π^{0} at High Q^{2} in the Quark Valence Regime.

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of x_{B} (0.36, 0.48, and 0.

A molecular dynamics study of protein denaturation induced by sulfonate-based surfactants.

Microsecond timescale explicit-solvent atomistic simulations were carried out to investigate how anionic surfactants modulate protein structure and dynamics. We found that lysozyme undergoes near-complete denaturation at the high concentration (> 0.1 M) of sodium pentadecyl sulfonate (SPDS), while only partial denaturation occurs at the concentration slightly below 0.

Accurate Determination of the Neutron Skin Thickness of ^{208}Pb through Parity-Violation in Electron Scattering.

We report a precision measurement of the parity-violating asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{208}Pb. We measure A_{PV}=550±16(stat)±8(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(Q^{2}=0.00616  GeV^{2})=0.

Probing Few-Body Nuclear Dynamics via ^{3}H and ^{3}He (e,e^{'}p)pn Cross-Section Measurements.

We report the first measurement of the (e,e^{'}p) three-body breakup reaction cross sections in helium-3 (^{3}He) and tritium (^{3}H) at large momentum transfer [⟨Q^{2}⟩≈1.9  (GeV/c)^{2}] and x_{B}>1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40≤p_{miss}≤500  MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon.

Precision measurement of the neutral pion lifetime.

The explicit breaking of the axial symmetry by quantum fluctuations gives rise to the so-called axial anomaly. This phenomenon is solely responsible for the decay of the neutral pion π into two photons (γγ), leading to its unusually short lifetime. We precisely measured the decay width Γ of the [Formula: see text] process.

Spiked gold nanotriangles: formation, characterization and applications in surface-enhanced Raman spectroscopy and plasmon-enhanced catalysis.

We show the formation of metallic spikes on the surface of gold nanotriangles (AuNTs) by using the same reduction process which has been used for the synthesis of gold nanostars. We confirm that silver nitrate operates as a shape-directing agent in combination with ascorbic acid as the reducing agent and investigate the mechanism by dissecting the contribution of each component, , anionic surfactant dioctyl sodium sulfosuccinate (AOT), ascorbic acid (AA), and AgNO. Molecular dynamics (MD) simulations show that AA attaches to the AOT bilayer of nanotriangles, and covers the surface of gold clusters, which is of special relevance for the spike formation process at the AuNT surface.

Molecular dynamics study of ACBP denaturation in alkyl sulfates demonstrates possible pathways of unfolding through fused surfactant clusters.

Anionic surfactants denature proteins at low millimolar concentrations, yet little is known about the underlying molecular mechanisms. Here, we undertake 1-μs-long atomistic molecular dynamics simulations of the denaturation of acyl coenzyme A binding protein (ACBP) and compare our results with previously published and new experimental data. Since increasing surfactant chain length is known to lead to more rapid denaturation, we studied denaturation using both the medium-length alkyl chain surfactant sodium dodecyl sulfate (SDS) and the long alkyl chain surfactant sodium hexadecyl sulfate (SHS).

A small proton charge radius from an electron-proton scattering experiment.

Elastic electron-proton scattering (e-p) and the spectroscopy of hydrogen atoms are the two methods traditionally used to determine the proton charge radius, r. In 2010, a new method using muonic hydrogen atoms found a substantial discrepancy compared with previous results, which became known as the 'proton radius puzzle'. Despite experimental and theoretical efforts, the puzzle remains unresolved.

AOT Bilayer Adsorption on Gold Surfaces: A Molecular Dynamics Study.

A molecular dynamics study was done to reveal the adsorption properties of sodium dioctyl sulfosuccinate (AOT) bilayers on gold Au(111) surfaces. Examining the rotational mobility of AOT molecules, we track that the correlation time of AOT molecules on the adsorbed layer is much higher. The data estimating the diffusive motion of AOT molecule show a substantially lower rate of diffusion (∼10 cm/s) in the adsorbed layers in comparison to other ones.

Publisher's Note: JLab Measurements of the ^{3}He Form Factors at Large Momentum Transfers [Phys. Rev. Lett. 119, 162501 (2017)].

This corrects the article DOI: 10.1103/PhysRevLett.119.

A glimpse of gluons through deeply virtual compton scattering on the proton.

The internal structure of nucleons (protons and neutrons) remains one of the greatest outstanding problems in modern nuclear physics. By scattering high-energy electrons off a proton we are able to resolve its fundamental constituents and probe their momenta and positions. Here we investigate the dynamics of quarks and gluons inside nucleons using deeply virtual Compton scattering (DVCS)-a highly virtual photon scatters off the proton, which subsequently radiates a photon.

JLab Measurements of the ^{3}He Form Factors at Large Momentum Transfers.

The charge and magnetic form factors, F_{C} and F_{M}, respectively, of ^{3}He are extracted in the kinematic range 25  fm^{-2}≤Q^{2}≤61  fm^{-2} from elastic electron scattering by detecting ^{3}He recoil nuclei and scattered electrons in coincidence with the two High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements find evidence for the existence of a second diffraction minimum for the magnetic form factor at Q^{2}=49.3  fm^{-2} and for the charge form factor at Q^{2}=62.

Rosenbluth Separation of the π^{0} Electroproduction Cross Section Off the Neutron.

We report the first longitudinal-transverse separation of the deeply virtual exclusive π^{0} electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure functions dσ_{L}/dt, dσ_{T}/dt, dσ_{LT}/dt, and dσ_{TT}/dt are extracted as a function of the momentum transfer to the recoil system at Q^{2}=1.75  GeV^{2} and x_{B}=0.

Rosenbluth Separation of the π^{0} Electroproduction Cross Section.

We present deeply virtual π^{0} electroproduction cross-section measurements at x_{B}=0.36 and three different Q^{2} values ranging from 1.5 to 2  GeV^{2}, obtained from Jefferson Lab Hall A experiment E07-007.

Measurement of the Target-Normal Single-Spin Asymmetry in Quasielastic Scattering from the Reaction (3)He(↑)(e,e').

We report the first measurement of the target single-spin asymmetry, A(y), in quasielastic scattering from the inclusive reaction (3)He(↑)(e,e') on a (3)He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A nonzero A(y) can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the substructure of the nucleon.

Polarization Transfer in Wide-Angle Compton Scattering and Single-Pion Photoproduction from the Proton.

Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The wide-angle Compton scattering polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θ_{cm}^{p}=70°.

Postoperative Hypoxemia Is Common and Persistent: A Prospective Blinded Observational Study.

Background: The incidence, severity, and duration of postoperative oxygen desaturation in the general surgical population are poorly characterized. We therefore used continuous pulse oximetry to quantify arterial oxygen saturation (SpO2) in a cross-section of patients having noncardiac surgery.

Methods: Oxygen saturation, blinded to clinicians, was recorded at 1-minute intervals in patients >45 years old for up to 48 hours after noncardiac surgery in 1250 patients from Cleveland Clinic Main Campus and 250 patients from the Juravinski Hospital.