Physical Sciences and Mathematics Commons^™

Systematic Errors In Intro Lab Video Analysis, John Zwart, Kayt E. Frisch, Tim Martin

Faculty Work Comprehensive List

In video analysis lab experiments, students frequently find large discrepancies between results based on self-filmed videos and expected values (e.g. for g determined by a fit to projectile motion data). These differences are frequently far larger than the uncertainty calculated from their fit. Using an inexpensive point-and-shoot camera with a 4x optical zoom to record video, we investigated two possible causes of this error: the effect of placing the reference meter stick at a different object-to-camera distance and the effect of the motion of interest being in a plane not perpendicular to the camera lens. When we observed these phenomena …

Measurement Of The Target-Normal Single-Spin Asymmetry In Quasielastic Scattering From The Reaction 3He↑(E,E′ ), Chiranjib Dutta, Wolfgang Korsch, Y.-W. Zhang, E. Long, M. Mihovilovič, G. Jin, K. Allada, B. Anderson, J. R. M. Annand, T. Averett, C. Ayerbe-Gayoso, W. Boeglin

Physics and Astronomy Faculty Publications

We report the first measurement of the target single-spin asymmetry, A_y, in quasielastic scattering from the inclusive reaction ³He^↑(e,e′ ) on a ³He 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. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at Q²=0.13, 0.46, and …

Precision Measurement Of The Longitudinal Double-Spin Asymmetry For Inclusive Jet Production In Polarized Proton Collisions At √S=200 Gev, James K. Adkins, Renee H. Fatemi, Suvarna Ramachandran, Grant D. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer

Physics and Astronomy Faculty Publications

We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, A_LL, in polarized pp collisions at center-of-mass energy √s=200  GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. The measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x>0.05.

Measurements Of Dielectron Production In Au + Au Collisions At √SNn = 200 Gev From The Star Experiment, James K. Adkins, Renee H. Fatemi, Suvarna Ramachandran, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev

Physics and Astronomy Faculty Publications

We report on measurements of dielectron (e⁺e⁻) production in Au + Au collisions at a center-of-mass energy of 200 GeV per nucleon-nucleon pair using the STAR detector at BNL Relativistic Heavy Ion Collider. Systematic measurements of the dielectron yield as a function of transverse momentum (p_T) and collision centrality show an enhancement compared to a cocktail simulation of hadronic sources in the low invariant-mass region (M_ee < 1 GeV/c²). This enhancement cannot be reproduced by the ρ-meson vacuum spectral function. In minimumbias collisions, in the invariant-mass range of 0.30–0.76 …

First Measurement Of The Atomic Electric Dipole Moment Of 225Ra, R. H. Parker, M. R. Dietrich, M. R. Kalita, N. D. Lemke, K. G. Bailey, M. Bishof, J. P. Greene, R. J. Holt, Wolfgang Korsch, Z.-T. Lu, P. Mueller, T. P. O'Connor, J. T. Singh

Physics and Astronomy Faculty Publications

The radioactive radium-225 (²²⁵Ra) atom is a favorable case to search for a permanent electric dipole moment. Because of its strong nuclear octupole deformation and large atomic mass, ²²⁵Ra is particularly sensitive to interactions in the nuclear medium that violate both time-reversal symmetry and parity. We have developed a cold-atom technique to study the spin precession of ²²⁵Ra atoms held in an optical dipole trap, and demonstrated the principle of this method by completing the first measurement of its atomic electric dipole moment, reaching an upper limit of |d(²²⁵Ra)|<5.0×10⁻²²  e cm …

Measuring Strain In Trusses, Spencer Metzsch

Senior Theses

Strain is an important quantity in engineering design and materials science that relates the deformation of a material to its original length, through a percentage. Different materials exhibit particular qualities under loading, for example the amount of strain due to a certain magnitude of force, or the amount of strain that can be borne before failure. This experiment aims to compare the relative strengths of three common truss configurations by measuring the strain in their members under loading. The Queen’s post truss was found to be the best at minimizing strain under similar loading conditions.

Measurement Of The Formation Rate Of Muonic Hydrogen Molecules, V. A. Andreev, T. I. Banks, R. M. Carey, T. A. Case, S. M. Clayton, K. M. Crowe, J. Deutsch, J. Egger, S. J. Freedman, V. A. Ganzha, Tim Gorringe, F. E. Gray, D. W. Hertzog, M. Hildebrandt, P. Kammel, B. Kiburg, S. Knaack, P. A. Kravtsov, A. G. Krivshich, B. Lauss, K. R. Lynch, E. M. Maev, O. E. Maev, F. Mulhauser, C. Petitjean, G. E. Petrov, R. Prieels, G. N. Schapkin, G. G. Semenchuk, M. A. Soroka, Vladimir Tishchenko, A. A. Vasilyev, A. A. Vorobyov, M. E. Vznuzdaev, P. Winter

Physics and Astronomy Faculty Publications

Background: The rate λ_ppμ characterizes the formation of ppμ molecules in collisions of muonic pμ atoms with hydrogen. In measurements of the basic weak muon capture reaction on the proton to determine the pseudoscalar coupling g_P, capture occurs from both atomic and molecular states. Thus knowledge of λ_ppμ is required for a correct interpretation of these experiments.

Purpose: Recently the MuCap experiment has measured the capture rate Λ_S from the singlet pμ atom, employing a low-density active target to suppress ppμ formation [V. Andreev et al. (MuCap Collaboration), Phys. Rev. Lett. 110, 012504 (2013) …

Automatic Classification Of Harmonic Data Using $K$-Means And Least Square Support Vector Machine, Hüseyi̇n Eri̇şti̇, Vedat Tümen, Özal Yildirim, Belkis Eri̇şti̇, Yakup Demi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an effective classification approach to classify harmonic data has been proposed. In the proposed classifier approach, harmonic data obtained through a 3-phase system have been classified by using $k$-means and least square support vector machine (LS-SVM) models. In order to obtain class details regarding harmonic data, a $k$-means clustering algorithm has been applied to these data first. The training of the LS-SVM model has been realized with the class details obtained through the $k$-means algorithm. To increase the efficiency of the LS-SVM model, the regularization and kernel parameters of this model have been determined with a grid …