Physical Sciences and Mathematics Commons^™

Sea Quarks Contribution To The Nucleon Magnetic Moment And Charge Radius At The Physical Point, Raza Sabbir Sufian, Yi-Bo Yang, Jian Liang, Terrence Draper, Keh-Fei Liu

Physics and Astronomy Faculty Publications

We report a comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon magnetic moment, charge radius, and the electric and magnetic form factors. The lattice QCD calculation includes ensembles across several lattice volumes and lattice spacings with one of the ensembles at the physical pion mass. We adopt a model-independent extrapolation of the nucleon magnetic moment and the charge radius. We have performed a simultaneous chiral, infinite volume, and continuum extrapolation in a global fit to calculate results in the continuum limit. We find that the combined light and strange disconnected-sea quarks contribution to the nucleon …

Coherent Diffractive Photoproduction Of Ρ0 Mesons On Gold Nuclei At 200 Gev/Nucleon-Pair At The Relativistic Heavy Ion Collider, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, D. Brown, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

The STAR Collaboration reports on the photoproduction of π⁺π⁻ pairs in gold-gold collisions at a center-of-mass energy of 200 GeV/nucleon-pair. These pion pairs are produced when a nearly real photon emitted by one ion scatters from the other ion.

We fit the π⁺π⁻ invariant-mass spectrum with a combination of ρ⁰ and ω resonances and a direct π⁺π⁻ continuum. This is the first observation of the ω in ultraperipheral collisions, and the first measurement of ρ−ω interference at energies where photoproduction is dominated by Pomeron exchange. The ω amplitude is consistent …

Measurement Of The Vector And Tensor Asymmetries At Large Missing Momentum In Quasielastic (E→,E'P Electron Scattering From Deuterium, A. Degrush, A. Maschinot, T. Akdogan, R. Alarcon, W. Bertozzi, E. Booth, T. Botto, J. R. Calarco, B. Clasie, Christopher Crawford, K. Dow, M. Farkhondeh, Renee H. Fatemi, O. Filoti, W. Franklin, H. Gao, E. Geis, S. Gilad, D. K. Hasell, P. Karpius, M. Kohl, H. Kolster, T. Lee, J. Matthews, K. Mcilhany, N. Meitanis, R. Milner, J. Rapaport, R. Redwine, J. Seely

Physics and Astronomy Faculty Publications

We report the measurement of the beam-vector and tensor asymmetries A^V_ed and A^T_d in quasielastic (e^→,e′p) electrodisintegration of the deuteron at the MIT-Bates Linear Accelerator Center up to missing momentum of 500  MeV/c. Data were collected simultaneously over a momentum transfer range 0.1 < Q² < 0.5  (GeV/c)² with the Bates Large Acceptance Spectrometer Toroid using an internal deuterium gas target polarized sequentially in both vector and tensor states. The data are compared with calculations. The beam-vector asymmetry AVed is found to be directly sensitive to the D-wave …

Lifetimes In 124Te: Examining Critical-Point Symmetry In The Te Nuclei, S. F. Hicks, J. R. Vanhoy, P. G. Burkett, B. R. Champine, S. J. Etzkorn, P. E. Garrett, Steven W. Yates, Minfang Yeh

Physics and Astronomy Faculty Publications

The Doppler-shift attenuation method following inelastic neutron scattering was used to determine the lifetimes of nuclear levels to 3.3-MeV excitation in ¹²⁴Te. Level energies and spins, γ-ray energies and branching ratios, and multipole-mixing ratios were deduced from measured γ-ray angular distributions at incident neutron energies of 2.40 and 3.30 MeV, γ-ray excitation functions, and γγ coincidence measurements. The newly obtained reduced transition probabilities and level energies for ¹²⁴Te were compared to critical-point symmetry model predictions. The E(5) and β⁴ potential critical-point symmetries were also investigated in ¹²²Te and ¹²⁶Te.

Strange Quark Magnetic Moment Of The Nucleon At The Physical Point, Raza Sabbir Sufian, Yi-Bo Yang, Andrei Alexandru, Terrence Draper, Jian Liang, Keh-Fei Liu

Physics and Astronomy Faculty Publications

We report a lattice QCD calculation of the strange quark contribution to the nucleon’s magnetic moment and charge radius. This analysis presents the first direct determination of strange electromagnetic form factors including at the physical pion mass. We perform a model-independent extraction of the strange magnetic moment and the strange charge radius from the electromagnetic form factors in the momentum transfer range of 0.051  GeV² ≲ Q² ≲ 1.31  GeV². The finite lattice spacing and finite volume corrections are included in a global fit with 24 valence quark masses on four lattices with different lattice spacings, …

Nuclear Structure Of 76Ge From Inelastic Neutron Scattering Measurements And Shell Model Calculations, Sharmistha Mukhopadhyay, Benjamin P. Crider, B. A. Brown, S. F. Ashley, Anagha Chakraborty, A. Kumar, Marcus T. Mcellistrem, Erin E. Peters, Francisco M. Prados-Estévez, Steven W. Yates

Physics and Astronomy Faculty Publications

The low-lying, low-spin levels of ⁷⁶Ge were studied with the (n,n′γ) reaction. Gamma-ray excitation function measurements were performed at incident neutron energies from 1.6 to 3.7 MeV, and γ-ray angular distributions were measured at neutron energies of 3.0 and 3.5 MeV. From these measurements, level spins, level lifetimes, γ-ray intensities, and multipole mixing ratios were determined. No evidence for a number of previously placed levels was found. Below 3.3 MeV, many new levels were identified, and the level scheme was re-evaluated. The B(E2) values support low-lying band structure. The 2 …