Physical Sciences and Mathematics Commons^™

Experimental Energy Levels And Partition Function Of The 12c2 Molecule, Tibor Furtenbacher, István Szabó, Attila G. Császár, Peter F. Bernath, Sergei N. Yurchenko, Jonathan Tennyson

Chemistry & Biochemistry Faculty Publications

The carbon dimer, the ¹²C₂ molecule, is ubiquitous in astronomical environments. Experimental-quality rovibronic energy levels are reported for ¹²C₂, based on rovibronic transitions measured for and among its singlet, triplet, and quintet electronic states, reported in 42 publications. The determination utilizes the Measured Active Rotational-Vibrational Energy Levels (MARVEL) technique. The 23,343 transitions measured experimentally and validated within this study determine 5699 rovibronic energy levels, 1325, 4309, and 65 levels for the singlet, triplet, and quintet states investigated, respectively. The MARVEL analysis provides rovibronic energies for six singlet, six triplet, and two quintet electronic states. For …

The Martian Surface Radiation Environment- A Comparison Of Models And Msl/Rad Measurements, Daniel Matthiä, Bent Ehresmann, Henning Lohf, Jan Köhler, Cary Zeitlin, Jan Appel, John W. Wilson

Mathematics & Statistics Faculty Publications

Context: The Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) has been measuring the radiation environment on the surface of Mars since August 6th 2012. MSL-RAD is the first instrument to provide detailed information about charged and neutral particle spectra and dose rates on the Martian surface, and one of the primary objectives of the RAD investigation is to help improve and validate current radiation transport models.

Aims: Applying different numerical transport models with boundary conditions derived from the MSL-RAD environment the goal of this work was to both provide predictions for the particle spectra and the radiation …

First Measurement Of The Helicity Asymmetry E In Ƞ Photoproduction On The Proton, I. Senderovich, B.T. Morrison, M. Dugger, B.G. Ritchie, E. Pasyuk, R. Tucker, J. Brock, C. Carlin, C.D. Keith, D. G. Meekins, Y. Prok

Physics Faculty Publications

Results are presented for the first measurement of the double-polarization helicity asymmetry E for the ƞ photoproduction reaction ɣp -> ηp. Data were obtained using the FROzen Spin Target (FROST) with the CLAS spectrometer in Hall B at Jefferson Lab, covering a range of center-of-mass energy W from threshold to 2.15 GeV and a large range in center-of-mass polar angle. As an initial application of these data, the results have been incorporated into the Jülich-Bonn model to examine the case for the existence of a narrow N* resonance between 1.66 and 1.70 GeV. The addition of these data to the …

Measurements Of Dⁿ² And Aⁿ¹: Probing The Neutron Spin Structure, D. Flay, M. Posik, D. S. Parno, K. Allada, M. Canan, C. Hyde, Jefferson Lab Hall A Collaboration

Physics Faculty Publications

We report on the results of the E06-014 experiment performed at Jefferson Lab in Hall A, where a precision measurement of the twist-3 matrix element d₂ of the neutron dⁿ₂ was conducted. The quantity dⁿ₂ represents the average color Lorentz force a struck quark experiences in a deep inelastic electron scattering event off a neutron due to its interaction with the hadronizing remnants. This color force was determined from a linear combination of the third moments of the ³He spin structure functions, g₁ and g₂, after nuclear corrections had been applied to these …