J. C. Cornejo
A5048067814- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- High-Energy Particle Collisions Research
- Dark Matter and Cosmic Phenomena
- Advanced NMR Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Quantum, superfluid, helium dynamics
- Particle Accelerators and Free-Electron Lasers
- Particle Detector Development and Performance
- Superconducting Materials and Applications
- Atomic and Molecular Physics
- Advanced Chemical Physics Studies
- Photocathodes and Microchannel Plates
- Medical Imaging Techniques and Applications
- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Crystallography and Radiation Phenomena
- Renal and Vascular Pathologies
- Nitric Oxide and Endothelin Effects
- Advanced Electron Microscopy Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Physics of Superconductivity and Magnetism
- Pharmacology and Obesity Treatment
Carnegie Mellon University
2018-2024
California State University Los Angeles
2005-2022
Williams (United States)
2012-2022
William & Mary
2012-2022
Thomas Jefferson National Accelerator Facility
2016
Hospital Privado
1987-1997
Universidad Nacional de Córdoba
1993
Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing strong interaction dynamics nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this Letter, we report new measurements factor ratio using recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5 GeV2. By extending range Q2 which G(E)(p) is accurately determined by more than 50%,...
We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in elastic scattering longitudinally polarized electrons from ^{48}Ca. measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction neutral weak form factor F_{W}(q=0.8733 fm^{-1})=0.1304±0.0052(stat)±0.0020(syst) and charge minus F_{ch}-F_{W}=0.0277±0.0055. The resulting neutron skin thickness R_{n}-R_{p}=0.121±0.026(exp)±0.024(model) fm is relatively thin yet consistent with many model...
We report the first measurement of target single spin asymmetries in semi-inclusive $^3{He}(e,e'\pi^\pm)X$ reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using 5.9 GeV electron beam, covers range 0.14 $< x <$ 0.34 with 1.3 $<Q^2<$ 2.7 GeV$^2$. Collins and Sivers moments were extracted from azimuthal angular dependence measured asymmetries. $\pi^\pm$ for $^3$He are consistent zero, except $\pi^+$ moment $x=0.34$, which deviates zero by 2.3$\sigma$....
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 Jefferson Lab. results experiment's commissioning run, constituting approximately 4% data collected experiment, are reported here. From these initial results, is A(ep)=-279±35 (stat) ± 31 (syst) ppb, which smallest and most precise ever scattering. small Q(2) this made possible...
Intensive theoretical and experimental efforts over the past decade have aimed at explaining discrepancy between data for proton electric to magnetic form factor ratio, G(E)/G(M), obtained separately from cross section polarization transfer measurements. One possible explanation this difference is a two-photon-exchange contribution. In an effort search effects beyond one-photon-exchange or Born approximation, we report measurements of observables in elastic H(e[over →],e(')p[over →])...
The GEp-III and GEp-2$\gamma$ experiments were carried out in Jefferson Lab's (JLab's) Hall C from 2007-2008, to extend the knowledge of $G_E^p/G_M^p$ highest practically achievable $Q^2$ search for effects beyond Born approximation polarization transfer observables elastic $\vec{e}p$ scattering. This article reports an expanded description common experimental apparatus data analysis procedure, results a final reanalysis both experiments, including previously unpublished full-acceptance...
We report the first measurement of double-spin asymmetry A{LT} for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized {3}He target. The kinematics focused valence quark region, 0.16<x<0.35 with 1.4<Q{2}<2.7 GeV{2}. corresponding neutron asymmetries were extracted from measured and proton over cross section ratios using effective polarization approximation. These new data probe transverse momentum dependent parton distribution...
We report the first measurement of target single-spin asymmetries (A$_N$) in inclusive hadron production reaction, $e~$+$~^3\text{He}^{\uparrow}\rightarrow h+X$, using a transversely polarized $^3$He target. The experiment was conducted at Jefferson Lab Hall A 5.9-GeV electron beam. Three types hadrons ($\pi^{\pm}$, $\text{K}^{\pm}$ and proton) were detected transverse momentum range 0.54 $<p_T<$ 0.74 GeV/c. $x_F$ for pions -0.29 $<x_F<$ -0.23 kaons -0.25 $<x_F<$-0.18. observed asymmetry...
We report the first measurement of target single spin asymmetries charged kaons produced in semi-inclusive deep inelastic scattering electrons off a transversely polarized $^3{\rm{He}}$ target. Both Collins and Sivers moments, which are related to nucleon transversity distributions, respectively, extracted over kinematic range 0.1$
Tests of the standard model particle physics rely on measurements with highly polarized electron beams. A new instrument achieves highest known precision for determining beam polarization low-energy (~1 GeV)
We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in elastic scattering 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, ^{208}Pb at very forward angles where most detailed theoretical calculations have been performed. The first measurements A_{n} for ^{40}Ca ^{48}Ca are found to be similar that consistent with expectations thus demonstrating validity nuclei Z≤20. also two new momentum transfers (Q^{2}) extending previous measurement. Our data...
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 proton magnetic form factor at high Q^{2} and double range over which a longitudinal or transverse separation can be performed. The difference between our results polarization data agrees that observed lower attributed hard two-photon exchange (TPE) effects, extending 8...
Radiation of the kidney often leads to renal failure. The contribution arterial hypertension development this complication is unclear. aim study was determine effects antihypertensive therapy in 1- and 2-kidney rat models radiation nephritis. Five groups Long Evans rats had X-irradiation left kidney. In 1 2, right undisturbed (2-kidney model). group 3, 4 5 underwent nephrectomy 21 days before (1-kidney Groups 3 received no drug treatment served as controls for each model. 2 enalapril 50 mg/l...
Results of the Jefferson Lab Hall A quasielastic 3He(e,e'p)pn measurements are presented. These were performed at fixed transferred momentum and energy, q=1502 MeV/c omega=840 MeV, respectively, for missing momenta p(m) up to 1 GeV/c energies in continuum region, pion threshold; this kinematic coverage is much more extensive than that any previous experiment. The cross section data presented along with effective density distribution compared theoretical models.
We report the first measurement of target-normal single-spin asymmetry in deep-inelastic scattering from inclusive reaction ${^{3}\mathrm{He}}^{\ensuremath{\uparrow}}(e,{e}^{\ensuremath{'}})X$ on a polarized $^{3}\mathrm{He}$ gas target. Assuming time-reversal invariance, this is strictly zero Born approximation but can be nonzero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using 5.89 GeV electron beam, covers range $1.7<W<2.9\text{...
The spin-structure functions $g_1$ and $g_2$, the spin-dependent partial cross-section $\sigma_\mathrm{TT}$ have been extracted from polarized cross-sections differences, $\Delta \sigma_{\parallel}\hspace{-0.06cm}\left(\nu,Q^{2}\right)$ \sigma_{\perp}\hspace{-0.06cm}\left(\nu,Q^{2}\right)$ measured for $\vec{^\textrm{3}\textrm{He}}(\vec{\textrm{e}},\textrm{e}')\textrm{X}$ reaction, in E97-110 experiment at Jefferson Lab. Polarized electrons with energies 1.147 to 4.404 GeV were scattered...
We have studied the quasielastic 3He(e,e(')p)2H reaction in perpendicular coplanar kinematics, with energy and momentum transferred by electron fixed at 840 MeV 1502 MeV/c, respectively. The cross section was measured for missing momenta up to 1000 while A(TL) asymmetry extracted 660 MeV/c. For 150 is described variational calculations using modern 3He wave functions. from 750 strong final-state interaction effects are observed. Near experimental more than an order of magnitude larger...
An experiment to measure single-spin asymmetries of semi-inclusive production charged pions in deep-inelastic scattering on a transversely polarized $^{3}\mathrm{He}$ target was performed at Jefferson Laboratory the kinematic region $0.16<x<0.35$ and $1.4<{Q}^{2}<2.7$ ${\mathrm{GeV}}^{2}$. Pretzelosity $^{3}\mathrm{He}$, which are expressed as convolution ${h}_{1T}^{\ensuremath{\perp}}$ transverse-momentum-dependent distribution functions Collins fragmentation leading order, were measured...
We report the first measurement of parity-violating elastic electron scattering asymmetry on ^{27}Al. The ^{27}Al is A_{PV}=2.16±0.11(stat)±0.16(syst) ppm, and was measured at ⟨Q^{2}⟩=0.02357±0.00010 GeV^{2}, ⟨θ_{lab}⟩=7.61°±0.02°, ⟨E_{lab}⟩=1.157 GeV with Q_{weak} apparatus Jefferson Lab. Predictions using a simple Born approximation as well more sophisticated distorted-wave calculations are in good agreement this result. From neutron radius R_{n}=2.89±0.12 fm determined many-models...
We have performed a novel comparison between electron-beam polarimeters based on Møller and Compton scattering. A sequence of polarization measurements were at low beam currents (<5μA) during the Qweak experiment in Hall-C Jefferson Lab. These current bracketed by regular high (180μA) operation polarimeter. All found to be consistent within experimental uncertainties 1% or less, demonstrating that electron does not depend significantly current. This result lends confidence common practice...
We report the measurement of beam-target double spin asymmetries $({A}_{\text{LT}})$ in inclusive production identified hadrons, $\stackrel{P\vec}{e}$ + ${}^{3}{\text{He}}^{\ensuremath{\uparrow}}\ensuremath{\rightarrow}h+X$, using a longitudinally polarized 5.9-GeV electron beam and transversely $^{3}\mathrm{He}$ target. Hadrons $({\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}},{K}^{\ifmmode\pm\else\textpm\fi{}}$, proton) were detected at ${16}^{\ensuremath{\circ}}$ with an average...
We report a high precision measurement of electron beam polarization using Compton polarimetry. The was made in experimental Hall A at Jefferson Lab during the CREX experiment 2020. total uncertainty dP/P=0.36% achieved detecting back-scattered photons from scattering process. This is highest accuracy ever reported, surpassing ground-breaking SLAC Large Detector (SLD) polarimeter. Such reaches level required for future flagship measurements to be by MOLLER and SoLID experiments.