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2005

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Articles 61 - 90 of 738

Full-Text Articles in Physics

Functional Characterization Of Core Promoter Elements: The Downstream Core Element Is Recognized By Taf1, Dong-Hoon Lee, Naum I. Gershenzon, Malavika Gupta, Ilya P. Ioshikhes, Danny Reinberg, Brian A. Lewis Nov 2005

Functional Characterization Of Core Promoter Elements: The Downstream Core Element Is Recognized By Taf1, Dong-Hoon Lee, Naum I. Gershenzon, Malavika Gupta, Ilya P. Ioshikhes, Danny Reinberg, Brian A. Lewis

Physics Faculty Publications

Downstream elements are a newly appreciated class of core promoter elements of RNA polymerase II-transcribed genes. The downstream core element (DCE) was discovered in the human β-globin promoter, and its sequence composition is distinct from that of the downstream promoter element (DPE). We show here that the DCE is a bona fide core promoter element present in a large number of promoters and with high incidence in promoters containing a TATA motif. Database analysis indicates that the DCE is found in diverse promoters, supporting its functional relevance in a variety of promoter contexts. The DCE consists of …

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The H Ii Region/Pdr Connection: Self-Consistent Calculations Of Physical Conditions In Star-Forming Regions, Nicholas Paul Abel, Gary J. Ferland, G. Shaw, Peter A. M. Van Hoof Nov 2005

The H Ii Region/Pdr Connection: Self-Consistent Calculations Of Physical Conditions In Star-Forming Regions, Nicholas Paul Abel, Gary J. Ferland, G. Shaw, Peter A. M. Van Hoof

Physics and Astronomy Faculty Publications

We have performed a series of calculations designed to reproduce infrared diagnostics used to determine physical conditions in star-forming regions. We self-consistently calculate the thermal and chemical structure of an H II region and photodissociation region (PDR) that are in pressure equilibrium. This differs from previous work, which used separate calculations for each gas phase. Our calculations span a wide range of stellar temperatures, gas densities, and ionization parameters. We describe improvements made to the spectral synthesis code Cloudy that made these calculations possible. These include the addition of a molecular network with ~1000 reactions involving 68 molecular species and …

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Kinetic Evaluation Of Human Cloned Coproporphyrinogen Oxidase Using A Ring Isomer Of The Natural Substrate, Marjorie A. Jones, Christopher L. Cooper, Timothy D. Lash Nov 2005

Kinetic Evaluation Of Human Cloned Coproporphyrinogen Oxidase Using A Ring Isomer Of The Natural Substrate, Marjorie A. Jones, Christopher L. Cooper, Timothy D. Lash

Faculty Publications – Chemistry

Background: The enzyme coproporphyrinogen oxidase (copro'gen oxidase) converts coproporphyrinogen-Ill (GIII) to protoporphyrinogen-IX via an intermediary monovinyl porphyrinogen. The A ring isomer coproporphyrinogen-IV (C-IV) has previously been shown to be a substrate for copro'gen oxidase derived from avian erythrocytes. In contrast to the authentic substrate (GIII) where only a small amount of the monovinyl intermediate is detected, C-IV gives rise to a monovinyl intermediate that accumulates before being converted to an isomer of protoporphyrinogen-IX. No kinetic studies have been carried out using the purified human copro'gen oxidase to evaluate its ability to process both the authentic substrate as well as analogs. …

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W Production At Large Transverse Momentum At The Large Hadron Collider, Richard J. Gonsalves, Nikolaos Kidonakis, Agustín Sabio Vera Nov 2005

W Production At Large Transverse Momentum At The Large Hadron Collider, Richard J. Gonsalves, Nikolaos Kidonakis, Agustín Sabio Vera

Faculty Articles

We study the production of W bosons at large transverse momentum in pp collisions at the Large Hadron Collider (LHC). We calculate the complete next-to-leading order (NLO) corrections to the differential cross section. We find that the NLO corrections provide a large increase to the cross section but, surprisingly, do not reduce the scale dependence relative to leading order (LO). We also calculate next-to-next-to-leading-order (NNLO) soft-gluon corrections and find that, although they are small, they significantly reduce the scale dependence thus providing a more stable theoretical prediction.

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Alignment Dynamics Of Slow Light Diffusion In Ultracold Atomic 85Rb, S. Balik, R. G. Olave, C. I. Sukenik, M. D. Havey, V. M. Datsyuk, I. M. Sokolov, D. V. Kupriyanov Nov 2005

Alignment Dynamics Of Slow Light Diffusion In Ultracold Atomic 85Rb, S. Balik, R. G. Olave, C. I. Sukenik, M. D. Havey, V. M. Datsyuk, I. M. Sokolov, D. V. Kupriyanov

Physics Faculty Publications

A combined experimental and theoretical investigation of time- and alignment-dependent propagation of light in an ultracold atomic gas of atomic 85Rb is reported. Coherences among the scattering amplitudes for light scattering off excited hyperfine levels produce strong variations of the light polarization in the vicinity of atomic resonance. Measurements are in excellent agreement with Monte Carlo simulations of the multiple scattering process.

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Laser-Dressed Vacuum Polarization In A Coulomb Field, A. I. Milstein, Ivan S. Terekhov, Ulrich D. Jentschura, Christoph H. Keitel Nov 2005

Laser-Dressed Vacuum Polarization In A Coulomb Field, A. I. Milstein, Ivan S. Terekhov, Ulrich D. Jentschura, Christoph H. Keitel

Physics Faculty Research & Creative Works

We investigate quantum electrodynamic effects under the influence of an external, time-dependent electromagnetic field, which mediates dynamic modifications of the radiative corrections. Specifically, we consider the quantum electrodynamic vacuum-polarization tensor under the influence of two external background fields: a strong laser field and a nuclear Coulomb field. We calculate the charge and current densities induced by a nuclear Coulomb field in the presence of a laser field. We find the corresponding induced scalar and vector potentials. The induced potential, in first-order perturbation theory, leads to a correction to atomic energy levels. The external laser field breaks the rotational symmetry of …

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Terahertz Studies Of The Dielectric Response And Second-Order Phonons In A Gase Crystal, B. L. Yu, F. Zeng, V. Kartazayev, R. R. Alfano, K. C. Mandal Oct 2005

Terahertz Studies Of The Dielectric Response And Second-Order Phonons In A Gase Crystal, B. L. Yu, F. Zeng, V. Kartazayev, R. R. Alfano, K. C. Mandal

Faculty Publications

No abstract provided.

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Sympathetic Cooling Route To Bose-Einstein Condensate And Fermi-Liquid Mixtures, Robin Côté, Roberto Onofrio, Eddy Timmermans Oct 2005

Sympathetic Cooling Route To Bose-Einstein Condensate And Fermi-Liquid Mixtures, Robin Côté, Roberto Onofrio, Eddy Timmermans

Dartmouth Scholarship

We discuss a sympathetic cooling strategy that can successfully mitigate fermion-hole heating in a dilute atomic Fermi-Bose mixture and access the temperature regime in which the fermions behave as a Fermi liquid. We introduce an energy-based formalism to describe the temperature dynamics with which we study a specific and promising mixture, composed of 6Li and 87Rb. Analyzing the harmonically trapped mixture, we find that the favorable features of this mixture are further enhanced by using different trapping frequencies for the two species.

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Using Genetic Algorithms To Map First-Principles Results To Model Hamiltonians: Application To The Generalized Ising Model For Alloys, Gus L. W. Hart, Volker Blum, Michael J. Walorski, Alex Zunger Oct 2005

Using Genetic Algorithms To Map First-Principles Results To Model Hamiltonians: Application To The Generalized Ising Model For Alloys, Gus L. W. Hart, Volker Blum, Michael J. Walorski, Alex Zunger

Faculty Publications

The cluster expansion method provides a standard framework to map first-principles generated energies for a few selected configurations of a binary alloy onto a finite set of pair and many-body interactions between the alloyed elements. These interactions describe the energetics of all possible configurations of the same alloy, which can hence be readily used to identify ground state structures and, through statistical mechanics solutions, find finite-temperature properties. In practice, the biggest challenge is to identify the types of interactions which are most important for a given alloy out of the many possibilities. We describe a genetic algorithm which automates this …

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Aggregation Behavior And Chromonic Liquid Crystal Properties Of An Anionic Monoazo Dye, Viva R. Horowitz , '05, L. A. Janowitz, Aaron L. Modic , '04, P. A. Heiney, Peter J. Collings Oct 2005

Aggregation Behavior And Chromonic Liquid Crystal Properties Of An Anionic Monoazo Dye, Viva R. Horowitz , '05, L. A. Janowitz, Aaron L. Modic , '04, P. A. Heiney, Peter J. Collings

Physics & Astronomy Faculty Works

X-ray scattering and various optical techniques are utilized to study the aggregation process and chromonic liquid crystal phase of the anionic monoazo dye Sunset Yellow FCF. The x-ray results demonstrate that aggregation involves pi-pi stacking of the molecules into columns, with the columns undergoing a phase transition to an orientationally ordered chromonic liquid crystal phase at high dye concentration. Optical absorption measurements on dilute solutions reveal that the aggregation takes place at all concentrations, with the average aggregation number increasing with concentration. A simple theory based on the law of mass action and an isodesmic aggregation process is in excellent …

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Numerical Integration Of The Teukolsky Equation In The Time Domain, Enrique Pazos-Avalos, Carlos O. Lousto Oct 2005

Numerical Integration Of The Teukolsky Equation In The Time Domain, Enrique Pazos-Avalos, Carlos O. Lousto

Physics & Astronomy Faculty Publications

We present a fourth-order convergent, (2+1)-dimensional, numerical formalism to solve the Teukolsky equation in the time domain. Our approach is first to rewrite the Teukolsky equation as a system of first-order differential equations. In this way we get a system that has the form of an advection equation. This is then used in combination with a series expansion of the solution in powers of time. To obtain a fourth-order scheme we kept terms up to fourth derivative in time and use the advectionlike system of differential equations to substitute the temporal derivatives by spatial derivatives. This scheme is applied to …

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Progress Towards Terahertz Acoustic Phonon Generation In Doping Superlattices, Thomas E. Wilson Oct 2005

Progress Towards Terahertz Acoustic Phonon Generation In Doping Superlattices, Thomas E. Wilson

Physics Faculty Research

Progress is described in experiments to generate coherent terahertz acoustic phonons in silicon doping superlattices by the resonant absorption of nanosecond-pulsed far-infrared laser radiation. Future experiments are proposed that would use the superlattice as a transducer in a terahertz cryogenic acoustic reflection microscope with sub-nanometer resolution.

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Integral Neutron Multiplicity Measurements From Cosmic Ray Interactions In Lead, Thomas E. Ward, Alexander A. Rimsky-Korsakov, Nikolai A. Kudryashev, Denis E. Beller Oct 2005

Integral Neutron Multiplicity Measurements From Cosmic Ray Interactions In Lead, Thomas E. Ward, Alexander A. Rimsky-Korsakov, Nikolai A. Kudryashev, Denis E. Beller

Transmutation Sciences Physics (TRP)

Sixty element 3He neutron multiplicity detector systems were designed, constructed and tested for use in cosmic ray experiments with a 30-cm cube lead target. A series of measurements were performed for the cosmic ray configuration at ground level (3 meters water equivalent, mwe), in the St. Petersburg metro tunnel (185 mwe), and in the Pyhäsalmi mine in Finland (583 and 1185 mwe). Anomalous coincidence events with charged cosmic ray particles at sea level produced events with 100-120 neutrons due possibly to the total disintegration of the Pb nucleus. These events were also detected at 185 mwe, but the particles …

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Incident Energy Dependence Of PT Correlations At Relativistic Energies, J. Adams, M.M. Aggarwal, Z. Ahammed, J. Amonett, B.D. Anderson, D. Arkhipkin, G.S. Averichev, S.K. Badyal, Y. Bai, J. Balewski, O. Barannikova, L.S. Barnby, J. Baudot, S. Bekele, V.V. Belaga, A. Bellingeri-Laurikainen, R. Bellwied, J. Berger, B.I. Bezverkhny, S. Bharadwaj, A. Bhasin, A.K. Bhati, V.S. Bhatia, H. Bichsel, J. Bielcik, J. Bielcikova, A. Billmeier, L.C. Bland, C.O. Blyth, B.E. Bonner, M. Botje, A. Boucham, J. Bouchet, A.V. Brandin, A. Bravar, M. Bystersky, R.V. Cadman, X.Z. Cai, H. Caines, M. Calderón De La Barca Sánchez, J. Castillo, O. Catu, D. Cebra, Z. Chajecki, P. Chaloupka, S. Chattopadhyay, H.F. Chen, Y. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, J.P. Coffin, T.M. Cormier, J.G. Cramer, H.J. Crawford, D. Das, S. Das, M. Daugherity, M.M. De Moura, T.G. Dedovich, A.A. Derevschikov, L. Didenko, T. Dietel, S.M. Dogra, W.J. Dong, X. Dong, J.E. Draper, F. Du, A.K. Dubey, V.B. Dunin, J.C. Dunlop, M.R. Dutta Mazumdar, V. Eckardt, W.R. Edwards, L.G. Efimov, V. Emelianov, J. Engelage, G. Eppley, B. Erazmus, M. Estienne, P. Fachini, J. Faivre, R. Fatemi, J. Fedorisin, K. Filimonov, P. Filip, E. Finch, V. Fine, Y. Fisyak, J. Fu, C.A. Gagliardi, L. Gaillard, J. Gans, M.S. Ganti, F. Geurts, V. Ghazikhanian, P. Ghosh, J.E. Gonzalez, H. Gos, O. Grachov, O. Grebenyuk, D. Grosnick, S.M. Guertin, Y. Guo, A. Gupta, T.D. Gutierrez, T.J. Hallman, A. Hamed, D. Hardtke, J.W. Harris, M. Heinz, T.W. Henry, S. Hepplemann, B. Hippolyte, A. Hirsch, E. Hjort, G.W. Hoffmann, H.Z. Huang, S.L. Huang, E.W. Hughes, T.J. Humanic, G. Igo, A. Ishihara, P. Jacobs, W.W. Jacobs, M. Jedynak, H. Jiang, P.G. Jones, E.G. Judd, S. Kabana, K. Kang, M. Kaplan, D. Keane, A. Kechechyan, V.Yu. Khodyrev, J. Kiryluk, A. Kisiel, E.M. Kislov, J. Klay, S.R. Klein, D.D. Koetke, T. Kollegger, M. Kopytine, L. Kotchenda, K.L. Kowalik, M. Kramer, P. Kravtsov, V.I. Kravtsov, K. Krueger, C. Kuhn, A.I. Kulikov, A. Kumar, R. Kh. Kutuev, A.A. Kuznetsov, M.A.C. Lamont, J.M. Landgraf, S. Lange, F. Laue, J. Lauret, A. Lebedev, R. Lednicky, S. Lehocka, M.J. Levine, C. Li, Q. Li, Y. Li, G. Lin, S.J. Lindenbaum, M.A. Lisa, F. Liu, H. Liu, L. Liu, Q.J. Liu, Z. Liu, T. Ljubicic, W.J. Llope, H. Long, R.S. Longacre, M. Lopez-Noriega, W.A. Love, Y. Lu, T. Ludlam, D. Lynn, G.L. Ma, J.G. Ma, Y.G. Ma, D. Magestro, S. Mahajan, D.P. Mahapatra, R. Majka, L.K. Mangotra, R. Manweiler, S. Margetis, C. Markert, L. Martin, J.N. Marx, H.S. Matis, Yu.A. Matulenko, C.J. Mcclain, T.S. Mcshane, F. Meissner, Yu. Melnick, A. Meschanin, M.L. Miller, N.G. Minaev, C. Mironov, A. Mischke, D.K. Mishra, J. Mitchell, B. Mohanty, L. Molnar, C.F. Moore, D.A. Morozov, M.G. Munhoz, B.K. Nandi, S.K. Nayak, T.K. Nayak, J.M. Nelson, P.K. Netrakanti, V.A. Nikitin, L.V. Nogach, S.B. Nurushev, G. Odyniec, A. Ogawa, V. Okorokov, M. Oldenburg, D. Olson, S.K. Pal, Y. Panebratsev, S.Y. Panitkin, A.I. Pavlinov, T. Pawlak, T. Peitzmann, V. Perevoztchikov, C. Perkins, W. Peryt, V.A. Petrov, S.C. Phatak, R. Picha, M. Planinic, J. Pluta, N. Porile, J. Porter, A.M. Poskanzer, M. Potekhin, E. Potrebenikova, B.V.K.S. Potukuchi, D. Prindle, C. Pruneau, J. Putschke, G. Rakness, R. Raniwala, S. Raniwala, O. Ravel, R.L. Ray, S.V. Razin, D. Reichhold, J.G. Reid, J. Reinnarth, G. Renault, F Retiere, A. Ridiger, H.G. Ritter, J.B. Roberts, O.V. Rogachevskiy, J.L. Romero, A. Rose, C. Roy, L. Ruan, M.J. Russcher, R. Sahoo, I. Sakrejda, S. Salur, J. Sandweiss, M. Sarsour, I. Savin, P.S. Sazhin, J. Schambach, R.P. Scharenberg, N. Schmitz, K. Schweda, J. Seger, P. Seyboth, E. Shahaliev, M. Shao, W. Shao, M. Sharma, W.Q. Shen, K.E. Shestermanov, S.S. Shimanskiy, E. Sichtermann, F. Simon, R.N. Singaraju, N. Smirnov, R. Snellings, G. Sood, P. Sorensen, J. Sowinski, J. Speltz, H.M. Spinka, B. Srivastava, A. Stadnik, T.D.S. Stanislaus, R. Stock, A. Stolpovsky, M. Strikhanov, B. Stringfellow, A.A.P. Suaide, E. Sugarbaker, C. Suire, M. Sumbera, B. Surrow, M. Swanger, T.J.M. Symons, A. Szanto De Toledo, A. Tai, J. Takahashi, A.H. Tang, T. Tarnowsky, D. Thein, J.H. Thomas, S. Timoshenko, M. Tokarev, S. Trentalange, R.E. Tribble, O.D. Tsai, J. Ulery, T. Ullrich, D.G. Underwood, G. Van Buren, M. Van Leeuwen, A.M. Vander Molen, R. Varma, I.M. Vasilevski, A.N. Vasiliev, R. Vernet, S.E. Vigdor, Y.P. Viyogi, S. Vokal, S.A. Voloshin, W.T. Waggoner, F. Wang, G. Wang, G. Wang, X.L. Wang, Y. Wang, Y. Wang, Z.M. Wang, H. Ward, J.W. Watson, J.C. Webb, G.D. Westfall, A. Wetzler, C. A. Whitten Jr., H. Wieman, S.W. Wissink, R. Witt, J. Wood, J. Wu, N. Xu, Z. Xu, Z.Z. Xu, E. Yamamoto, P. Yepes, V.I. Yurevich, I. Zborovsky, H. Zhang, W.M. Zhang, Y. Zhang, Z.P. Zhang, R. Zoulkarneev, Y. Zoulkarneeva, A.N. Zubarev Oct 2005

Incident Energy Dependence Of PT Correlations At Relativistic Energies, J. Adams, M.M. Aggarwal, Z. Ahammed, J. Amonett, B.D. Anderson, D. Arkhipkin, G.S. Averichev, S.K. Badyal, Y. Bai, J. Balewski, O. Barannikova, L.S. Barnby, J. Baudot, S. Bekele, V.V. Belaga, A. Bellingeri-Laurikainen, R. Bellwied, J. Berger, B.I. Bezverkhny, S. Bharadwaj, A. Bhasin, A.K. Bhati, V.S. Bhatia, H. Bichsel, J. Bielcik, J. Bielcikova, A. Billmeier, L.C. Bland, C.O. Blyth, B.E. Bonner, M. Botje, A. Boucham, J. Bouchet, A.V. Brandin, A. Bravar, M. Bystersky, R.V. Cadman, X.Z. Cai, H. Caines, M. Calderón De La Barca Sánchez, J. Castillo, O. Catu, D. Cebra, Z. Chajecki, P. Chaloupka, S. Chattopadhyay, H.F. Chen, Y. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, J.P. Coffin, T.M. Cormier, J.G. Cramer, H.J. Crawford, D. Das, S. Das, M. Daugherity, M.M. De Moura, T.G. Dedovich, A.A. Derevschikov, L. Didenko, T. Dietel, S.M. Dogra, W.J. Dong, X. Dong, J.E. Draper, F. Du, A.K. Dubey, V.B. Dunin, J.C. Dunlop, M.R. Dutta Mazumdar, V. Eckardt, W.R. Edwards, L.G. Efimov, V. Emelianov, J. Engelage, G. Eppley, B. Erazmus, M. Estienne, P. Fachini, J. Faivre, R. Fatemi, J. Fedorisin, K. Filimonov, P. Filip, E. Finch, V. Fine, Y. Fisyak, J. Fu, C.A. Gagliardi, L. Gaillard, J. Gans, M.S. Ganti, F. Geurts, V. Ghazikhanian, P. Ghosh, J.E. Gonzalez, H. Gos, O. Grachov, O. Grebenyuk, D. Grosnick, S.M. Guertin, Y. Guo, A. Gupta, T.D. Gutierrez, T.J. Hallman, A. Hamed, D. Hardtke, J.W. Harris, M. Heinz, T.W. Henry, S. Hepplemann, B. Hippolyte, A. Hirsch, E. Hjort, G.W. Hoffmann, H.Z. Huang, S.L. Huang, E.W. Hughes, T.J. Humanic, G. Igo, A. Ishihara, P. Jacobs, W.W. Jacobs, M. Jedynak, H. Jiang, P.G. Jones, E.G. Judd, S. Kabana, K. Kang, M. Kaplan, D. Keane, A. Kechechyan, V.Yu. Khodyrev, J. Kiryluk, A. Kisiel, E.M. Kislov, J. Klay, S.R. Klein, D.D. Koetke, T. Kollegger, M. Kopytine, L. Kotchenda, K.L. Kowalik, M. Kramer, P. Kravtsov, V.I. Kravtsov, K. Krueger, C. Kuhn, A.I. Kulikov, A. Kumar, R. Kh. Kutuev, A.A. Kuznetsov, M.A.C. Lamont, J.M. Landgraf, S. Lange, F. Laue, J. Lauret, A. Lebedev, R. Lednicky, S. Lehocka, M.J. Levine, C. Li, Q. Li, Y. Li, G. Lin, S.J. Lindenbaum, M.A. Lisa, F. Liu, H. Liu, L. Liu, Q.J. Liu, Z. Liu, T. Ljubicic, W.J. Llope, H. Long, R.S. Longacre, M. Lopez-Noriega, W.A. Love, Y. Lu, T. Ludlam, D. Lynn, G.L. Ma, J.G. Ma, Y.G. Ma, D. Magestro, S. Mahajan, D.P. Mahapatra, R. Majka, L.K. Mangotra, R. Manweiler, S. Margetis, C. Markert, L. Martin, J.N. Marx, H.S. Matis, Yu.A. Matulenko, C.J. Mcclain, T.S. Mcshane, F. Meissner, Yu. Melnick, A. Meschanin, M.L. Miller, N.G. Minaev, C. Mironov, A. Mischke, D.K. Mishra, J. Mitchell, B. Mohanty, L. Molnar, C.F. Moore, D.A. Morozov, M.G. Munhoz, B.K. Nandi, S.K. Nayak, T.K. Nayak, J.M. Nelson, P.K. Netrakanti, V.A. Nikitin, L.V. Nogach, S.B. Nurushev, G. Odyniec, A. Ogawa, V. Okorokov, M. Oldenburg, D. Olson, S.K. Pal, Y. Panebratsev, S.Y. Panitkin, A.I. Pavlinov, T. Pawlak, T. Peitzmann, V. Perevoztchikov, C. Perkins, W. Peryt, V.A. Petrov, S.C. Phatak, R. Picha, M. Planinic, J. Pluta, N. Porile, J. Porter, A.M. Poskanzer, M. Potekhin, E. Potrebenikova, B.V.K.S. Potukuchi, D. Prindle, C. Pruneau, J. Putschke, G. Rakness, R. Raniwala, S. Raniwala, O. Ravel, R.L. Ray, S.V. Razin, D. Reichhold, J.G. Reid, J. Reinnarth, G. Renault, F Retiere, A. Ridiger, H.G. Ritter, J.B. Roberts, O.V. Rogachevskiy, J.L. Romero, A. Rose, C. Roy, L. Ruan, M.J. Russcher, R. Sahoo, I. Sakrejda, S. Salur, J. Sandweiss, M. Sarsour, I. Savin, P.S. Sazhin, J. Schambach, R.P. Scharenberg, N. Schmitz, K. Schweda, J. Seger, P. Seyboth, E. Shahaliev, M. Shao, W. Shao, M. Sharma, W.Q. Shen, K.E. Shestermanov, S.S. Shimanskiy, E. Sichtermann, F. Simon, R.N. Singaraju, N. Smirnov, R. Snellings, G. Sood, P. Sorensen, J. Sowinski, J. Speltz, H.M. Spinka, B. Srivastava, A. Stadnik, T.D.S. Stanislaus, R. Stock, A. Stolpovsky, M. Strikhanov, B. Stringfellow, A.A.P. Suaide, E. Sugarbaker, C. Suire, M. Sumbera, B. Surrow, M. Swanger, T.J.M. Symons, A. Szanto De Toledo, A. Tai, J. Takahashi, A.H. Tang, T. Tarnowsky, D. Thein, J.H. Thomas, S. Timoshenko, M. Tokarev, S. Trentalange, R.E. Tribble, O.D. Tsai, J. Ulery, T. Ullrich, D.G. Underwood, G. Van Buren, M. Van Leeuwen, A.M. Vander Molen, R. Varma, I.M. Vasilevski, A.N. Vasiliev, R. Vernet, S.E. Vigdor, Y.P. Viyogi, S. Vokal, S.A. Voloshin, W.T. Waggoner, F. Wang, G. Wang, G. Wang, X.L. Wang, Y. Wang, Y. Wang, Z.M. Wang, H. Ward, J.W. Watson, J.C. Webb, G.D. Westfall, A. Wetzler, C. A. Whitten Jr., H. Wieman, S.W. Wissink, R. Witt, J. Wood, J. Wu, N. Xu, Z. Xu, Z.Z. Xu, E. Yamamoto, P. Yepes, V.I. Yurevich, I. Zborovsky, H. Zhang, W.M. Zhang, Y. Zhang, Z.P. Zhang, R. Zoulkarneev, Y. Zoulkarneeva, A.N. Zubarev

Physics

We present results for two-particle transverse momentum correlations, ⟨Δpt,iΔpt,j⟩, as a function of event centrality for Au+Au collisions at √sNN=20, 62, 130, and 200 GeV at the BNL Relativistic Heavy Ion Collider. We observe correlations decreasing with centrality that are similar at all four incident energies. The correlations multiplied by the multiplicity density increase with incident energy, and the centrality dependence may show evidence of processes such as thermalization, jet production, or the saturation of transverse flow. The square root of the correlations divided by the event-wise average transverse momentum per event shows little …

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Incident Energy Dependence Of PT Correlations At Relativistic Energies, Star Collaboration, Thomas D. Gutierrez Oct 2005

Incident Energy Dependence Of PT Correlations At Relativistic Energies, Star Collaboration, Thomas D. Gutierrez

Physics

We present results for two-particle transverse momentum correlations, ⟨Δpt,iΔpt,j⟩, as a function of event centrality for Au+Au collisions at √sNN=20, 62, 130, and 200 GeV at the BNL Relativistic Heavy Ion Collider. We observe correlations decreasing with centrality that are similar at all four incident energies. The correlations multiplied by the multiplicity density increase with incident energy, and the centrality dependence may show evidence of processes such as thermalization, jet production, or the saturation of transverse flow. The square root of the correlations divided by the event-wise average transverse momentum per event shows little …

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Structural Control Of Vertically Aligned Multiwalled Carbon Nanotubes By Radio-Frequency Plasmas, Jitendra Menda, Benjamin Ulmen, Lakshman Kumar Vanga, Vijaya Kayastha, Yoke Khin Yap, Zhengwei Pan, Ilia Ivanov, Alex Puretzky, David Geohegan Oct 2005

Structural Control Of Vertically Aligned Multiwalled Carbon Nanotubes By Radio-Frequency Plasmas, Jitendra Menda, Benjamin Ulmen, Lakshman Kumar Vanga, Vijaya Kayastha, Yoke Khin Yap, Zhengwei Pan, Ilia Ivanov, Alex Puretzky, David Geohegan

Department of Physics Publications

Plasma-enhanced chemical vapor deposition is the only technique for growing individual vertically aligned multiwalled carbon nanotubes (VA-MWCNTs) at desired locations. Inferior graphitic order has been a long-standing issue that has prevented realistic applications of these VA-MWCNTs. Previously, these VA-MWCNTs were grown by a one-plasma approach. Here, we demonstrate the capability of controlling graphitic order and diameters of VA-MWCNTs by decoupling the functions of the conventional single plasma into a dual-plasma configuration. Our results indicate that the ionic flux and kinetic energy of the growth species are important for improving graphitic order of VA-MWCMTs.

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Direct Enumeration Of Alloy Configurations For Electronic Structural Properties, Gus L. W. Hart, Peter A. Graf, Kwiseon Kim, Wesley B. Jones Oct 2005

Direct Enumeration Of Alloy Configurations For Electronic Structural Properties, Gus L. W. Hart, Peter A. Graf, Kwiseon Kim, Wesley B. Jones

Faculty Publications

We present and apply an approach to directly enumerate the band gaps and effective masses of all possible zinc blende-based alloy configurations whose unit cell contains up to a specified number of atoms. This method allows us to map the space of band gaps and effective masses versus alloy composition and atomic configuration. We demonstrate that a large number of band gaps and effective masses are available. We also discuss convergence of the method with respect to unit cell size and the combined optimization of band gap and effective mass for AlGaAs and GaInP semiconductor alloys.

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Results From Cuoricino Experiment And Prospects For Cuore, M Pedretti, R Ardito, C Arnaboldi, D. R. Artusa, F. T. Avignone Iii, M. Balata, I Bandac, M Barucci, J.W. Beeman, F Bellini, C Brofferio, C Bucci, S Capelli, F. Capozzi, L Carbone, S Cebrian, M Clemenza, C Cosmelli, O Cremonesi, R. J. Creswick, I Dafinei, A. De Waard, M Diemoz, M. Dolinski, H. A. Farach, F Ferroni, E Fiorini, C Gargiulo, E Guardincerri, A Giuliani, P Gorla, T.D. Gutierrez, E.E. Haller, Ig Irastorza, E. Longo, G Maier, R. Maruyama, S Morganti, S Nisi, C Nones, E.B. Norman, A Nucciotti, E. Olivieri, P Ottonello, M Pallavicini, V Palmieri, M Pavan, G Pessina, S Pirro, E Previtali, B. Quiter, L Risegari, C Rosenfeld, S Sangiorgio, M Sisti, A.R. Smith, L Torres, G. Ventura, N. Xu, L Zanotti Oct 2005

Results From Cuoricino Experiment And Prospects For Cuore, M Pedretti, R Ardito, C Arnaboldi, D. R. Artusa, F. T. Avignone Iii, M. Balata, I Bandac, M Barucci, J.W. Beeman, F Bellini, C Brofferio, C Bucci, S Capelli, F. Capozzi, L Carbone, S Cebrian, M Clemenza, C Cosmelli, O Cremonesi, R. J. Creswick, I Dafinei, A. De Waard, M Diemoz, M. Dolinski, H. A. Farach, F Ferroni, E Fiorini, C Gargiulo, E Guardincerri, A Giuliani, P Gorla, T.D. Gutierrez, E.E. Haller, Ig Irastorza, E. Longo, G Maier, R. Maruyama, S Morganti, S Nisi, C Nones, E.B. Norman, A Nucciotti, E. Olivieri, P Ottonello, M Pallavicini, V Palmieri, M Pavan, G Pessina, S Pirro, E Previtali, B. Quiter, L Risegari, C Rosenfeld, S Sangiorgio, M Sisti, A.R. Smith, L Torres, G. Ventura, N. Xu, L Zanotti

Physics

Cuoricino is a taking data bolometric experiment searching for neutrinoless double beta decay (0νDBD) of 130Te. The detector consists of an array of large cubic TeO2 crystal bolometers. Cuoricino works at about 10 mK in the Gran Sasso Underground Laboratory. Good energy resolutions were obtained (2.1 keV at 911 keV and 3.9 keV at 2615 keV at best). The counting rate in the region of 0νDBD is 0.18±0.02 c/keV/kg/y. The limit for the 0νDBD half lifetime is 2.0 × 1024 years at the 90% of C.L. This results correspond to a limit for the effective neutrino mass …

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Notes On (Twisted) Lattice Supersymmetry, Simon Catterall Oct 2005

Notes On (Twisted) Lattice Supersymmetry, Simon Catterall

Physics - All Scholarship

We describe a new approach to the problem of putting supersymmetric theories on the lattice. The basic idea is to discretize a {\it twisted} formulation of the supersymmetric theory. For certain theories with extended supersymmetry these twisted formulations contain only integer spin fields. The twisting exposes a scalar nilpotent supercharge which generates an exact lattice symmetry. We gives examples from quantum mechanics, sigma models and Yang-Mills theories.

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Distributions Of Charged Hadrons Associated With High Transverse Momentum Particles In Pp And Au+Au Collisions At √SNn = 200 Gev, J. Adams, C. Adler, M.M. Aggarwal, Z. Ahammed, J. Amonett, B.D. Anderson, D. Arkhipkin, G.S. Averichev, S.K. Badyal, J. Balewski, O. Barannikova, L.S. Barnby, J. Baudot, S. Bekele, V.V. Belaga, R. Bellwied, J. Berger, B.I. Bezverkhny, S. Bhardwaj, A.K. Bhati, H. Bichsel, A. Billmeier, L.C. Bland, C.O. Blyth, B.E. Bonner, M. Botje, A. Boucham, A.V. Brandin, A. Bravar, R.V. Cadman, X.Z. Cai, H. Caines, M. Calderón De La Barca Sánchez, J. Carroll, J. Castillo, D. Cebra, P. Chaloupka, S. Chattopadhyay, H.F. Chen, Y. Chen, S.P. Chernenko, M. Cherney, A. Chikanian, W. Christie, J.P. Coffin, T.M. Cormier, J.G. Cramer, H.J. Crawford, D. Das, S. Das, A.A. Derevschikov, L. Didenko, T. Dietel, W.J. Dong, X. Dong, J.E. Draper, F. Du, A.K. Dubey, V.B. Dunin, J.C. Dunlop, M.R. Dutta Mazumdar, V. Eckardt, L.G. Efimov, V. Emelianov, J. Engelage, G. Eppley, B. Erazmus, M. Estienne, P. Fachini, V. Faine, J. Faivre, R. Fatemi, K. Filimonov, P. Filip, E. Finch, Y. Fisyak, D. Flierl, K.J. Foley, J. Fu, C.A. Gagliardi, N. Gagunashvili, J. Gans, M.S. Ganti, L. Gaudichet, F. Geurts, V. Ghazikhanian, P. Ghosh, J.E. Gonzalez, O. Grachov, O. Grebenyuk, S. Gronstal, D. Grosnick, S.M. Guertin, A. Gupta, T.D. Gutierrez, T.J. Hallman, A. Hamed, D. Hardtke, J.W. Harris, M. Heinz, T.W. Henry, S. Hepplemann, T. Herston, B. Hippolyte, A. Hirsch, E. Hjort, G.W. Hoffmann, M. Horsley, H.Z. Huang, S.L. Huang, E. Hughes, T.J. Humanic, G. Igo, A. Ishihara, P. Jacobs, W.W. Jacobs, M. Janik, H. Jiang, I. Johnson, P.G. Jones, E.G. Judd, S. Kabana, M. Kaplan, D. Keane, V.Yu. Khodyrev, J. Kiryluk, A. Kisiel, J. Klay, S.R. Klein, A. Klyachko, D.D. Koetke, T. Kollegger, M. Kopytine, L. Kotchenda, A.D. Kovalenko, M. Kramer, P. Kravtsov, V.I. Kravtsov, K. Krueger, C. Kuhn, A.I. Kulikov, A. Kumar, G.J. Kunde, C.L. Kunz, R. Kh. Kutuev, A.A. Kuznetsov, M.A.C. Lamont, J.M. Landgraf, S. Lange, B. Lasiuk, F. Laue, J. Lauret, A. Lebedev, R. Lednicky, M.J. Levine, C. Li, Q. Li, S.J. Lindenbaum, M.A. Lisa, F. Liu, L. Liu, Z. Liu, Q.J. Liu, T. Ljubicic, W.J. Llope, H. Long, R.S. Longacre, M. Lopez-Noriega, W.A. Love, T. Ludlam, D. Lynn, J. Ma, Y.G. Ma, D. Magestro, S. Mahajan, L.K. Mangotra, D.P. Mahapatra, R. Majka, R. Manweiler, S. Margetis, C. Markert, L. Martin, J.N. Marx, H.S. Matis, Yu.A. Matulenko, C.J. Mcclain, T.S. Mcshane, F. Meissner, Yu. Melnick, A. Meschanin, M.L. Miller, Z. Milosevich, N.G. Minaev, C. Mironov, A. Mischke, D.K. Mishra, J. Mitchell, B. Mohanty, L. Molnar, C.F. Moore, M.J. Mora-Corral, D.A. Morozov, V. Morozov, M.M. De Moura, M.G. Munhoz, B.K. Nandi, S.K. Nayak, T.K. Nayak, J.M. Nelson, P.K. Netrakanti, V.A. Nikitin, L.V. Nogach, B. Norman, S.B. Nurushev, G. Odyniec, A. Ogawa, V. Okorokov, M. Oldenburg, D. Olson, G. Paic, S.K. Pal, Y. Panebratsev, S.Y. Panitkin, A.I. Pavlinov, T. Pawlak, T. Peitzmann, V. Perevoztchikov, C. Perkins, W. Peryt, V.A. Petrov, S.C. Phatak, R. Picha, M. Planinic, J. Pluta, N. Porile, J. Porter, A.M. Poskanzer, M. Potekhin, E. Potrebenikova, B.V.K.S. Potukuchi, D. Prindle, C. Pruneau, J. Putschke, G. Rai, G. Rakness, R. Raniwala, S. Raniwala, O. Ravel, R.L. Ray, S.V. Razin, D. Reichhold, J.G. Reid, G. Renault, F. Retiere, A. Ridiger, H.G. Ritter, J.B. Roberts, O.V. Rogachevskiy, J.L. Romero, A. Rose, C. Roy, L. Ruan, R. Sahoo, I. Sakrejda, S. Salur, J. Sandweiss, I. Savin, J. Schambach, R.P. Scharenberg, N. Schmitz, L.S. Schroeder, K. Schweda, J. Seger, P. Seyboth, E. Shahaliev, M. Shao, W. Shao, M. Sharma, K.E. Shestermanov, S.S. Shimanskiy, R.N. Singaraju, F. Simon, G. Skoro, N. Smirnov, R. Snellings, G. Sood, P. Sorensen, J. Sowinski, J. Speltz, H.M. Spinka, B. Srivastava, T.D.S. Stanislaus, R. Stock, A. Stolpovsky, M. Strikhanov, B. Stringfellow, C. Struck, A.A.P. Suaide, E. Sugarbaker, C. Suire, M. Šumbera, B. Surrow, T.J.M. Symons, A. Szanto De Toledo, P. Szarwas, A. Tai, J. Takahashi, A.H. Tang, D. Thein, J.H. Thomas, S. Timoshenko, M. Tokarev, M.B. Tonjes, T.A. Trainor, S. Trentalange, R.E. Tribble, O.D. Tsai, T. Ullrich, D.G. Underwood, G. Van Buren, A.M. Vander Molen, R. Varma, I.M. Vasilevski, A.N. Vasiliev, R. Vernet, S.E. Vigdor, Y.P. Viyogi, S.A. Voloshin, M. Vznuzdaev, W.T. Waggoner, F. Wang, G. Wang, X.L. Wang, Y. Wang, Z.M Wang, H. Ward, J.W. Watson, J.C. Webb, R. Wells, G.D. Westfall, C. A. Whitten Jr., H. Wieman, R. Willson, S.W. Wissink, R. Witt, J. Wood, J. Wu, N. Xu, Z. Xu, Z.Z. Xu, E. Yamamoto, P. Yepes, V.I. Yurevich, B. Yuting, Y.V. Zanevski, H. Zhang, W.M. Zhang, Z.P. Zhang, Z.P. Zhaomin, Z.P. Zizong, P.A. Żołnierczuk, R. Zoulkarneev, Y. Zoulkarneeva, A.N. Zubarev Oct 2005

Distributions Of Charged Hadrons Associated With High Transverse Momentum Particles In Pp And Au+Au Collisions At √SNn = 200 Gev, J. Adams, C. Adler, M.M. Aggarwal, Z. Ahammed, J. Amonett, B.D. Anderson, D. Arkhipkin, G.S. Averichev, S.K. Badyal, J. Balewski, O. Barannikova, L.S. Barnby, J. Baudot, S. Bekele, V.V. Belaga, R. Bellwied, J. Berger, B.I. Bezverkhny, S. Bhardwaj, A.K. Bhati, H. Bichsel, A. Billmeier, L.C. Bland, C.O. Blyth, B.E. Bonner, M. Botje, A. Boucham, A.V. Brandin, A. Bravar, R.V. Cadman, X.Z. Cai, H. Caines, M. Calderón De La Barca Sánchez, J. Carroll, J. Castillo, D. Cebra, P. Chaloupka, S. Chattopadhyay, H.F. Chen, Y. Chen, S.P. Chernenko, M. Cherney, A. Chikanian, W. Christie, J.P. Coffin, T.M. Cormier, J.G. Cramer, H.J. Crawford, D. Das, S. Das, A.A. Derevschikov, L. Didenko, T. Dietel, W.J. Dong, X. Dong, J.E. Draper, F. Du, A.K. Dubey, V.B. Dunin, J.C. Dunlop, M.R. Dutta Mazumdar, V. Eckardt, L.G. Efimov, V. Emelianov, J. Engelage, G. Eppley, B. Erazmus, M. Estienne, P. Fachini, V. Faine, J. Faivre, R. Fatemi, K. Filimonov, P. Filip, E. Finch, Y. Fisyak, D. Flierl, K.J. Foley, J. Fu, C.A. Gagliardi, N. Gagunashvili, J. Gans, M.S. Ganti, L. Gaudichet, F. Geurts, V. Ghazikhanian, P. Ghosh, J.E. Gonzalez, O. Grachov, O. Grebenyuk, S. Gronstal, D. Grosnick, S.M. Guertin, A. Gupta, T.D. Gutierrez, T.J. Hallman, A. Hamed, D. Hardtke, J.W. Harris, M. Heinz, T.W. Henry, S. Hepplemann, T. Herston, B. Hippolyte, A. Hirsch, E. Hjort, G.W. Hoffmann, M. Horsley, H.Z. Huang, S.L. Huang, E. Hughes, T.J. Humanic, G. Igo, A. Ishihara, P. Jacobs, W.W. Jacobs, M. Janik, H. Jiang, I. Johnson, P.G. Jones, E.G. Judd, S. Kabana, M. Kaplan, D. Keane, V.Yu. Khodyrev, J. Kiryluk, A. Kisiel, J. Klay, S.R. Klein, A. Klyachko, D.D. Koetke, T. Kollegger, M. Kopytine, L. Kotchenda, A.D. Kovalenko, M. Kramer, P. Kravtsov, V.I. Kravtsov, K. Krueger, C. Kuhn, A.I. Kulikov, A. Kumar, G.J. Kunde, C.L. Kunz, R. Kh. Kutuev, A.A. Kuznetsov, M.A.C. Lamont, J.M. Landgraf, S. Lange, B. Lasiuk, F. Laue, J. Lauret, A. Lebedev, R. Lednicky, M.J. Levine, C. Li, Q. Li, S.J. Lindenbaum, M.A. Lisa, F. Liu, L. Liu, Z. Liu, Q.J. Liu, T. Ljubicic, W.J. Llope, H. Long, R.S. Longacre, M. Lopez-Noriega, W.A. Love, T. Ludlam, D. Lynn, J. Ma, Y.G. Ma, D. Magestro, S. Mahajan, L.K. Mangotra, D.P. Mahapatra, R. Majka, R. Manweiler, S. Margetis, C. Markert, L. Martin, J.N. Marx, H.S. Matis, Yu.A. Matulenko, C.J. Mcclain, T.S. Mcshane, F. Meissner, Yu. Melnick, A. Meschanin, M.L. Miller, Z. Milosevich, N.G. Minaev, C. Mironov, A. Mischke, D.K. Mishra, J. Mitchell, B. Mohanty, L. Molnar, C.F. Moore, M.J. Mora-Corral, D.A. Morozov, V. Morozov, M.M. De Moura, M.G. Munhoz, B.K. Nandi, S.K. Nayak, T.K. Nayak, J.M. Nelson, P.K. Netrakanti, V.A. Nikitin, L.V. Nogach, B. Norman, S.B. Nurushev, G. Odyniec, A. Ogawa, V. Okorokov, M. Oldenburg, D. Olson, G. Paic, S.K. Pal, Y. Panebratsev, S.Y. Panitkin, A.I. Pavlinov, T. Pawlak, T. Peitzmann, V. Perevoztchikov, C. Perkins, W. Peryt, V.A. Petrov, S.C. Phatak, R. Picha, M. Planinic, J. Pluta, N. Porile, J. Porter, A.M. Poskanzer, M. Potekhin, E. Potrebenikova, B.V.K.S. Potukuchi, D. Prindle, C. Pruneau, J. Putschke, G. Rai, G. Rakness, R. Raniwala, S. Raniwala, O. Ravel, R.L. Ray, S.V. Razin, D. Reichhold, J.G. Reid, G. Renault, F. Retiere, A. Ridiger, H.G. Ritter, J.B. Roberts, O.V. Rogachevskiy, J.L. Romero, A. Rose, C. Roy, L. Ruan, R. Sahoo, I. Sakrejda, S. Salur, J. Sandweiss, I. Savin, J. Schambach, R.P. Scharenberg, N. Schmitz, L.S. Schroeder, K. Schweda, J. Seger, P. Seyboth, E. Shahaliev, M. Shao, W. Shao, M. Sharma, K.E. Shestermanov, S.S. Shimanskiy, R.N. Singaraju, F. Simon, G. Skoro, N. Smirnov, R. Snellings, G. Sood, P. Sorensen, J. Sowinski, J. Speltz, H.M. Spinka, B. Srivastava, T.D.S. Stanislaus, R. Stock, A. Stolpovsky, M. Strikhanov, B. Stringfellow, C. Struck, A.A.P. Suaide, E. Sugarbaker, C. Suire, M. Šumbera, B. Surrow, T.J.M. Symons, A. Szanto De Toledo, P. Szarwas, A. Tai, J. Takahashi, A.H. Tang, D. Thein, J.H. Thomas, S. Timoshenko, M. Tokarev, M.B. Tonjes, T.A. Trainor, S. Trentalange, R.E. Tribble, O.D. Tsai, T. Ullrich, D.G. Underwood, G. Van Buren, A.M. Vander Molen, R. Varma, I.M. Vasilevski, A.N. Vasiliev, R. Vernet, S.E. Vigdor, Y.P. Viyogi, S.A. Voloshin, M. Vznuzdaev, W.T. Waggoner, F. Wang, G. Wang, X.L. Wang, Y. Wang, Z.M Wang, H. Ward, J.W. Watson, J.C. Webb, R. Wells, G.D. Westfall, C. A. Whitten Jr., H. Wieman, R. Willson, S.W. Wissink, R. Witt, J. Wood, J. Wu, N. Xu, Z. Xu, Z.Z. Xu, E. Yamamoto, P. Yepes, V.I. Yurevich, B. Yuting, Y.V. Zanevski, H. Zhang, W.M. Zhang, Z.P. Zhang, Z.P. Zhaomin, Z.P. Zizong, P.A. Żołnierczuk, R. Zoulkarneev, Y. Zoulkarneeva, A.N. Zubarev

Physics

Charged hadrons in 0.15⊥<4  GeV/c associated with particles of ptrig⊥>4  GeV/c are reconstructed in pp and Au+Au collisions at √sNN=200  GeV. The associated multiplicity and p⊥magnitude sum are found to increase from pp to central Au+Au collisions. The associated p⊥distributions, while similar in shape on the nearside, are significantly softened on the awayside in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the awayside fragments approach equilibration with the medium traversed.

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Lattice Formulation Of {\Cal N}=4 Super Yang-Mills Theory, Simon Catterall Oct 2005

Lattice Formulation Of {\Cal N}=4 Super Yang-Mills Theory, Simon Catterall

Physics - All Scholarship

We construct a lattice action for {\cal N}=4 super Yang-Mills theory in four dimensions which is local, gauge invariant, free of spectrum doubling and possesses a single exact supersymmetry. Our construction starts from the observation that the fermions of the continuum theory can be mapped into the component fields of a single real anticommuting Kahler-Dirac field. The original supersymmetry algebra then implies the existence of a nilpotent scalar supercharge Q and a corresponding set of bosonic superpartners. Using this field content we write down a Q-exact action and show that, with an appropriate change of variables, it reduces to a …

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Dirac-Kähler Fermions And Exact Lattice Supersymmetry, Simon Catterall Oct 2005

Dirac-Kähler Fermions And Exact Lattice Supersymmetry, Simon Catterall

Physics - All Scholarship

We discuss a new approach to putting supersymmetric theories on the lattice. The basic idea is to start from a {\it twisted} formulation of the underlying supersymmetric theory in which the fermions are represented as grassmann valued antisymmetric tensor fields. The original supersymmetry algebra is replaced by a twisted algebra which contains a scalar nilpotent supercharge Q. Furthermore the action of the theory can then be written as the Q-variation of some function. The case of {\cal N}=2 super Yang-Mills theory in two dimensions is discussed in some detail. We then present our proposal for discretizing this theory and derive …

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Semiconductor Nanowire Laser And Nanowire Waveguide Electro-Optic Modulators, Andrew B. Greytak, Carl J. Barrelet, Yat Li, Charles M. Lieber Oct 2005

Semiconductor Nanowire Laser And Nanowire Waveguide Electro-Optic Modulators, Andrew B. Greytak, Carl J. Barrelet, Yat Li, Charles M. Lieber

Faculty Publications

Electric field modulation of visible and ultraviolet nanoscale lasers consisting of single CdS or GaN nanowires has been achieved using integrated, microfabricated electrodes. Modulation of laser emission intensity is achieved with no detectable change in the laser wavelength. The devices can also be operated below the lasing threshold to modulate the intensity of light propagating within the nanowire waveguide. Studies of the electric field dependence in devices of varied geometry indicate that modulation is due to an electroabsorption mechanism. These findings expand opportunities for multicolor, nanowire-based photonic devices and circuits.

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Grain Boundary Scars On Spherical Crystals, Mark Bowick, Thomas Einert, Peter Lipowsky, Jorg Schilling, Andreas R. Bausch Oct 2005

Grain Boundary Scars On Spherical Crystals, Mark Bowick, Thomas Einert, Peter Lipowsky, Jorg Schilling, Andreas R. Bausch

Physics - All Scholarship

We present an experimental system suitable for producing spherical crystals and for observing the distribution of lattice defects (disclinations and dislocations) on a significant fraction (50%) of the sphere. The introduction of fluorescently labeled particles enables us to determine the location and orientation of grain boundary scars. We find that the total number of scars and the number of excess dislocations per scar agree with theoretical predictions and that the geometrical centers of the scars are roughly positioned at the vertices of an icosahedron.

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Magnetization Reversal Of Fe Films On Ag Submicrometer Pyramidal Islands, Chin-Chung Yu, Yeong-Der Yao, Sy_Hwang Liou Oct 2005

Magnetization Reversal Of Fe Films On Ag Submicrometer Pyramidal Islands, Chin-Chung Yu, Yeong-Der Yao, Sy_Hwang Liou

Sy-Hwang Liou Publications

Ag submicrometer pyramidal islands with a (100) truncated top and four (111) sidewalls were successfully fabricated on Si(100) substrates at a deposition temperature of 500/spl deg/C. The magnetization reversal of 30 nm thick Fe films grown on Ag pyramidal islands was studied by magnetic force microscopy. The magnetization reversal of Fe films was first started at the sidewalls of pyramidal islands. Then, the formation and propagation of wall-like structures were observed under a higher external magnetic field, namely 95 Oe. The magnetic domain images indicated that the Fe films grown on the sidewalls of pyramidal islands and the strength of …

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Partition-Based Interpolation For Color Filter Array Demosaicking And Super-Resolution Reconstruction, Min Shao, Kenneth E. Barner, Russell C. Hardie Oct 2005

Partition-Based Interpolation For Color Filter Array Demosaicking And Super-Resolution Reconstruction, Min Shao, Kenneth E. Barner, Russell C. Hardie

Electrical and Computer Engineering Faculty Publications

A class of partition-based interpolators that addresses a variety of image interpolation applications are proposed. The proposed interpolators first partition an image into a finite set of partitions that capture local image structures. Missing high resolution pixels are then obtained through linear operations on neighboring pixels that exploit the captured image structure. By exploiting the local image structure, the proposed algorithm produces excellent performance on both edge and uniform regions. The presented results demonstrate that partition-based interpolation yields results superior to traditional and advanced algorithms in the applications of color filter array (CFA) demosaicking and super-resolution reconstruction.

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Traps In Algan/Gan/Sic Heterostructures Studied By Deep Level Transient Spectroscopy, Z-Q. Fang, David C. Look, D. H. Kim, I. Adesida Oct 2005

Traps In Algan/Gan/Sic Heterostructures Studied By Deep Level Transient Spectroscopy, Z-Q. Fang, David C. Look, D. H. Kim, I. Adesida

Physics Faculty Publications

AlGaN/GaN/SiC Schottky barrier diodes (SBDs), with and without Si3N4 passivation, have been characterized by temperature-dependent current-voltage and capacitance-voltage measurements, and deep level transient spectroscopy (DLTS). A dominant trap A1, with activation energy of 1.0 eV and apparent capture cross section of 2×10−12 cm2, has been observed in both unpassivated and passivated SBDs. Based on the well-known logarithmic dependence of DLTS peak height with filling pulse width for a line-defect related trap, A1, which is commonly observed in thin GaN layers grown by various techniques, is believed to be associated with …

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Arge-Encoded N-Acetyl-L-Ornithine Deacetylase From Escherichia Coli Contains A Dinuclear Metalloactive Site, Wade C. Mcgregor, Sabina I. Swierczek, Brian Bennett, Richard C. Holz Oct 2005

Arge-Encoded N-Acetyl-L-Ornithine Deacetylase From Escherichia Coli Contains A Dinuclear Metalloactive Site, Wade C. Mcgregor, Sabina I. Swierczek, Brian Bennett, Richard C. Holz

Physics Faculty Research and Publications

The catalytic and structural properties of the argE-encoded N-acetyl-l-ornithine deacetylase (ArgE) from Escherichia coli were investigated. On the basis of kinetic and ITC (isothermal titration calorimetry) data, Zn(II) binds to ArgE with Kd values that differ by ∼20 times. Moreover, ArgE exhibits ∼90% of its full catalytic activity upon addition of one metal ion. Therefore, ArgE behaves similarly to the aminopeptidase from Aeromonas proteolytica (AAP) in that one metal ion is the catalytic metal ion while the second likely plays a structural role. The N-acetyl-l-ornithine (NAO) deacetylase activity of ArgE showed a linear temperature dependence from …

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High-Resolution Angular Measurement Using Surface-Plasmon-Resonance Via Phase Interrogation At Optimal Incident Wavelengths, Hai-Pang Chiang, Jing-Lun Lin, Railing Chang, Sheng-Yu Su, P.T. Leung Oct 2005

High-Resolution Angular Measurement Using Surface-Plasmon-Resonance Via Phase Interrogation At Optimal Incident Wavelengths, Hai-Pang Chiang, Jing-Lun Lin, Railing Chang, Sheng-Yu Su, P.T. Leung

Physics Faculty Publications and Presentations

It is demonstrated that ultrahigh-resolution angular measurement can be achieved via surface-plasmon-resonance excitation in which the phase difference between p- and s-polarized reflected waves is monitored as a function of the incidence angle. Resolutions down to 1.9 x 10(-6) deg are obtained by performing the measurements at optimal incident wavelengths. This represents an order of magnitude improvement compared with previously reported values.

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Simplification Of The Stratton-Chu Vector Diffraction Integrals And Application To Light Propagation Through Curved Surfaces, Shekhar Guha, Glen D. Gillen Oct 2005

Simplification Of The Stratton-Chu Vector Diffraction Integrals And Application To Light Propagation Through Curved Surfaces, Shekhar Guha, Glen D. Gillen

Physics

The Stratton-Chu vector diffraction integrals are expressed in dimensionless forms and then numerically evaluated to describe light propagation originating from a plane and a curved surface without invoking paraxial approximation

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