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Full-Text Articles in Physical Sciences and Mathematics
Electron-Positron Annihilation Lifetime Spectroscopy Of Mgo And Aluminum-Doped Mgo, Elise Liebow
Electron-Positron Annihilation Lifetime Spectroscopy Of Mgo And Aluminum-Doped Mgo, Elise Liebow
Honors Theses
Radiation is a form of energy that can damage materials at an atomic level. This has implications for the mobility of radioactive waste through containment materials. We are characterizing atomic defects in materials by using Electron-Positron Annihilation Lifetime Spectroscopy (EPALS). When an electron and positron come into contact with each other, they annihilate and release two antiparallel 511-keV gamma rays. In a pristine crystalline sample, positrons can easily annihilate with electrons, but in a sample with vacancies/defects in the crystal structure, positrons take longer to annihilate. Therefore, the more vacancies in a sample, the longer the average lifetime of a …
Charged Particle Identification Using Calorimetry And Tracking At The Belle Ii Experiment, Joseph T. Nunziata, Atanu Pathak, Swagato Banerjee
Charged Particle Identification Using Calorimetry And Tracking At The Belle Ii Experiment, Joseph T. Nunziata, Atanu Pathak, Swagato Banerjee
Undergraduate Arts and Research Showcase
Particle identification (PID) is a critical procedure carried out in high energy physics experiments in search of new physics. When particles of matter (i.e., an electron) and antimatter (i.e., a positron) collide, new types of particles may form given certain conditions. Such particles may be classified as hadrons--which feel the strong nuclear force--and leptons--which do not. Identifying particles at the Belle II experiment is done by combining the measurement of energy deposited in the calorimeter with the measurement of track momentum in the tracker. In a tau lepton ($\tau$) decay sample, particles such as electrons, muons, and pions may be …
Resonances In E+ E− Annihilation Near 2.2 Gev, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu G. Kolomensky, M. Fritsch, H. Koch, T. Schroeder, R. Cheaib, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, Milind Purohit, Et. Al.
Resonances In E+ E− Annihilation Near 2.2 Gev, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu G. Kolomensky, M. Fritsch, H. Koch, T. Schroeder, R. Cheaib, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, Milind Purohit, Et. Al.
Faculty Publications
Using the initial-state radiation method, the e+e− → KSKL cross section from 1.98 to 2.54 GeV is measured in a data sample of 469 fb−1 collected with the BABAR detector. The results are used in conjunction with previous BABAR results for the e+e−→ K+K−, e+e− → π+π−, e+e− → π+π−η, and e+e− → ωππ cross sections to investigate the nature of the resonance structure recently observed by …
Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest Order, B. Wang, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato
Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest Order, B. Wang, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato
Physics Faculty Publications
Motivated by recently observed tension between O(α2s) calculations of very large transverse momentum dependence in both semi-inclusive deep inelastic scattering and Drell-Yan scattering, we repeat the details of the calculation through an O(α2s) transversely differential cross section. The results confirm earlier calculations, and provide further support to the observation that tension exists with current parton distribution and fragmentation functions.
Low Energy Positron Interactions With Biological Molecules, Indika Lasantha Wanniarachchi
Low Energy Positron Interactions With Biological Molecules, Indika Lasantha Wanniarachchi
Wayne State University Dissertations
Calculations of the positron density distribution which can be used for positrons bound to midsize and larger molecules have been tested for smaller molecules and subsequently applied to investigate the most likely e+e- annihilation sites for positrons interacting with biological molecules containing C, H, O, and N. In order to allow consideration of positrons bound to extended molecules with regions of different character and no particular symmetry, atom-centered positron basis sets of Gaussian-type functions were developed for positrons bound to molecules containing O, N, C, H, Li, Na, and Be. Testing shows that there is no need to scale the …
Selective Decay And Coherent Vortices In Two-Dimensional Incompressible Turbulence, William H. Matthaeus, W. Troy Stribling, Daniel Martinez, Sean Oughton, David Montgomery
Selective Decay And Coherent Vortices In Two-Dimensional Incompressible Turbulence, William H. Matthaeus, W. Troy Stribling, Daniel Martinez, Sean Oughton, David Montgomery
Dartmouth Scholarship
Numerical solution of two-dimensional incompressible hydrodynamics shows that states of a near-minimal ratio of enstrophy to energy can be attained in times short compared with the flow decay time, confirming the simplest turbulent selective decay conjecture, and suggesting that coherent vortex structures do not terminate nonlinear processes. After all possible vortex mergers occur, the vorticity attains a particlelike character, suggested by the late-time similarity of the streamlines to Ewald potential contours.