J. Connelly
A5040802046- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Nuclear Physics and Applications
- Advanced NMR Techniques and Applications
- Superconducting Materials and Applications
- Pleistocene-Era Hominins and Archaeology
- Particle Detector Development and Performance
- Astro and Planetary Science
- Magnetism in coordination complexes
- Atomic and Molecular Physics
- Photocathodes and Microchannel Plates
- Radiation Detection and Scintillator Technologies
- Archaeology and ancient environmental studies
- Pacific and Southeast Asian Studies
- Magnetic properties of thin films
- Algebraic and Geometric Analysis
- Magneto-Optical Properties and Applications
- Dark Matter and Cosmic Phenomena
- Electron Spin Resonance Studies
- Electron and X-Ray Spectroscopy Techniques
Australian Research Council
2024
James Cook University
2024
George Washington University
2001-2005
Campbell Collaboration
2000-2004
Duke University
2000
University of Edinburgh
2000
The reaction gamma p-->pi(+)K(-)K(+)n was studied at Jefferson Laboratory using a tagged photon beam with an energy range of 3-5.47 GeV. A narrow baryon state strangeness S=+1 and mass M=1555+/-10 MeV/c(2) observed in the nK(+) invariant spectrum. peak's width is consistent CLAS resolution (FWHM=26 MeV/c(2)), its statistical significance (7.8+/-1.0)sigma. positive has exotic structure cannot be described framework naive constituent quark model. predicted by chiral soliton model for Theta(+)...
The ratios of inclusive electron scattering cross sections $^4$He, $^{12}$C, and $^{56}$Fe to $^3$He have been measured for the first time. It is shown that these are independent $x_B$ at Q$^2>$1.4 (GeV/c)$^2$ $x_B>$ 1.5 where section depends primarily on high-momentum components nuclear wave function. observed scaling shows momentum distributions high-momenta same shape all nuclei differ only by a scale factor. onset $x_B >$1.5 consistent with kinematical expectation two nucleon short range...
Differential cross sections for gammap-->etap have been measured with tagged real photons incident photon energies from 0.75 to 1.95 GeV. Mesons were identified by missing mass reconstruction using kinematical information protons scattered in the production process. The data provide first extensive angular distribution measurements process above W=1.75 Comparison preliminary results a constituent quark model support suggestion that third S11 resonance approximately 1.8 GeV couples etaN channel.
New cross sections for the reaction e p-->e p eta are reported total center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q2 0.25--1.5 (GeV/c)(2). This large kinematic range allows extraction important new information about response functions, photocouplings, N coupling strengths baryon resonances. Newly observed structure at approximately 1.65 is shown to come from interference between S P waves can be interpreted with known Improved values derived photon amplitude...
Aboriginal manufacture and use of pottery was unknown in Australia prior to European settlement, despite well-known ceramic-making traditions southern Papua New Guinea, eastern Indonesia, the western Pacific. The absence ancient mainland has long puzzled researchers given other documented deep time exchange networks across continent close proximity pottery-bearing Lapita post-Lapita maritime communities Pacific with ocean-going watercraft sophisticated navigation abilities. We report oldest...
Double-polarization asymmetries for inclusive ep scattering were measured at Jefferson Lab using 2.6 and 4.3 GeV longitudinally polarized electrons incident on a NH3 target in the CLAS detector. The structure function g(1)(x,Q2) was extracted throughout nucleon resonance region into deep inelastic regime, Q(2)=0.15-1.64 GeV2. contributions to first moment Gamma(1)(Q2)= integral dx determined up Q(2)=1.2 Using parametrization g(1) unmeasured low x regions, complete estimated over this Q2...
Received 21 January 2004DOI:https://doi.org/10.1103/PhysRevLett.92.049902©2004 American Physical Society
The cross section for φ meson photoproduction on the proton has been measured first time up to a four-momentum transfer −t=4GeV2, using CLAS detector at Thomas Jefferson National Accelerator Facility. At low transfer, differential is well described by Pomeron exchange. large above −t=1.8GeV2, data support model where resolved into its simplest component, two gluons, which may couple any quark in and φ.Received 16 June 2000DOI:https://doi.org/10.1103/PhysRevLett.85.4682©2000 American Physical Society
We report the results of a new measurement spin structure functions deuteron in region moderate momentum transfer ($Q^2$ = 0.27 -- 1.3 (GeV/c)$^2$) and final hadronic state mass nucleon resonance ($W$ 1.08 2.0 GeV). scattered 2.5 GeV polarized continuous electron beam at Jefferson Lab off dynamically cryogenic solid target ($^{15}$ND$_3$) detected electrons with CEBAF Large Acceptance Spectrometer (CLAS). From our data, we extract longitudinal double asymmetry $A_{||}$ function $g_1^d$. Our...
We report on the first measurement of exclusive ${\ensuremath{\Xi}}^{\ensuremath{-}}(1321)$ hyperon photoproduction in $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{+}{K}^{+}{\ensuremath{\Xi}}^{\ensuremath{-}}$ for $3.2<{E}_{\ensuremath{\gamma}}<3.9$ GeV. The final state is identified by missing mass $p(\ensuremath{\gamma},{K}^{+}{K}^{+})X$ measured with CLAS detector at Jefferson Laboratory. have detected a significant number ground...
The reaction $e\stackrel{\ensuremath{\rightarrow}}{p}{e}^{\ensuremath{'}}{K}^{+}\ensuremath{\Lambda}(1520)$ with $\ensuremath{\Lambda}(1520)\ensuremath{\rightarrow}{p}^{\ensuremath{'}}{K}^{\ensuremath{-}}$ was studied at electron beam energies of 4.05, 4.25, and 4.46 GeV, using the CLAS detector Thomas Jefferson National Accelerator Facility. $\mathrm{cos}{\ensuremath{\theta}}_{{K}^{+}},$ ${\ensuremath{\varphi}}_{{K}^{+}},$ ${Q}^{2},$ W dependencies $\ensuremath{\Lambda}(1520)$...
Measurements of the angular distributions target and double spin asymmetries for Delta(1232) in exclusive channel (polarized-p polarized-e,e-prime p)pi0 obtained at Jefferson Lab Q2 range from 0.5 to 1.5 gev2 are presented. Results compared with unitary isobar model, dynamical models, effective Lagrangian theory. Sensitivity different models was observed, particularly relation description background terms on which asymmetry depends significantly.
The double spin asymmetry in the $\vec{e}\vec{p}\to e' \pi^+ n$ reaction has been measured for first time resonance region four-momentum transfer $Q^2=0.35-1.5$ GeV$^2$. Data were taken at Jefferson Lab with CLAS detector using a 2.6 GeV polarized electron beam incident on solid NH$_3$ target. Comparison predictions of phenomenological models shows strong sensitivity to contributions. Helicity-1/2 transitions are found be dominant second and third regions. is consistent faster rise $Q^2$...
As part of a measurement the cross section $\phi$ meson photoproduction to high momentum transfer, we measured polar angular decay distribution outgoing $K^+$ in channel $\phi \to K^+K^-$ center-of-mass frame (the helicity frame). We find that s-channel conservation (SCHC) holds kinematical range where $t$-channel exchange dominates (up $-t \sim 2.5$ GeV$^2$ for $E_{\gamma}$=3.6 GeV). Above this momentum, $u$-channel production and induces violation SCHC. The deduced value NN$ coupling...
Received 19 November 2002DOI:https://doi.org/10.1103/PhysRevLett.89.249904©2002 American Physical Society