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1

Finite Particle Number Approach to Quantum Physics.

National Technical Information Service (NTIS)

Bridgman has contended that the inside of an electron cannot be given operational meaning. The basic reason for this is taken to be that when relativity is coupled to quantum mechanics the uncertainty principle in energy requires the existence of an indef...

H. P. Noyes

1982-01-01

2

Quantum Optics, Diffraction Theory, and Elementary Particle Physics

Physical optics has expanded greatly in recent years. Though it remains part of the ancestry of elementary particle physics, there are once again lessons to be learned from it. I shall discuss several of these, including some that have emerged at CERN and Brookhaven.

None

2009-08-07

3

Quantum Optics, Diffraction Theory, and Elementary Particle Physics

Physical optics has expanded greatly in recent years. Though it remains part of the ancestry of elementary particle physics, there are once again lessons to be learned from it. I shall discuss several of these, including some that have emerged at CERN and Brookhaven.

None

2011-10-06

4

Lifshitz-Type Quantum Field Theories in Particle Physics

NASA Astrophysics Data System (ADS)

This introduction to Lifshitz-type field theories reviews some of its aspects in Particle Physics. Attractive features of these models are described with different examples, as the improvement of graphs convergence, the introduction of new renormalizable interactions, dynamical mass generation, asymptotic freedom, and other features related to more specific models. On the other hand, problems with the expected emergence of Lorentz symmetry in the IR are discussed, related to the different effective light cones seen by different particles when they interact.

Alexandre, Jean

5

Nuclear and particle physics applications of the Bohm picture of quantum mechanics

NASA Astrophysics Data System (ADS)

Aproximation methods for calculating individual particle/field motions in spacetime at the quantum level of accuracy (a key feature of the Bohm picture (BP) of quantum mechanics) are studied. This sharply illuminates not only the deep quantum structures underlying any observable quantum statistical laws of motion of particles and fields in spacetime, but also how the continuous merging of the so-called classical and quantal modes of description actually occurs, with no breaks anywhere. Modern textbook presentations of Quantum Theory are used throughout, but only to provide the necessary, already existing, tested formalisms and calculational techniques. New coherent insights, reinterpretations of old solutions and results, and new (in principle testable) quantitative and qualitative predictions can be obtained on the basis of the BP that complete the standard type of postdictions and predictions. Most of the dead wood still cluttering discussions on the meaning of Quantum Theory and the role of the BP is by-passed. We shall try to draw attention to the physics of this unfortunately hardly known novel formulation of Quantum Theory by giving additional illustrative examples inspired from the daily practices of contemporary Nuclear and Particle Physics, subjects that as yet have not been thoroughly reinterpreted within the BP. These fields of research offer excellent oppurtunities for explaining and illustrating the significance of time in quantum transitions, as well as the closely related features of quantum non-locality and quantum wholeness, as hard physical facts. We claim that in addition we can obtain a substantial gain in predictive powers of the underlying, all-encompassing, Quantum Theory.

Miranda, A.

2009-04-01

6

In Quantum Mechanics operators must be hermitian and, in a direct product space, symmetric. These properties are saved by Lie algebra operators but not by those of quantum algebras. A possible correspondence between observables and quantum algebra operators is suggested by extending the definition of matrix el- ements of a physical observable, including the eventual projection on the appro- priate

E. Celeghini; M. A. del Olmo

1969-01-01

7

Quantum Physics for Beginners.

ERIC Educational Resources Information Center

Suggests a new approach for teaching secondary school quantum physics. Reviews traditional approaches and presents some characteristics of the three-part "Quantum Physics for Beginners" project, including: quantum physics, quantum mechanics, and a short historical survey. (SK)

Strand, J.

1981-01-01

8

Research in theoretical particle physics

This report discusses the following topics in high energy physics: dynamical symmetry breaking and Schwinger-Dyson equation; consistency bound on the minimal model Higgs mass; tests of physics beyond the standard model; particle astrophysics; the interface between perturbative and non-perturbative QCD; cosmology; anisotropy in quantum networks and integer quantum hall behavior; anomalous color transparency; quantum treatment of solitons; color transparency; quantum stabilization of skyrmions; and casimir effect. (LSP)

McKay, D.W.; Munczek, H.; Ralston, J.

1992-05-01

9

Quantum chromodynamics (QCD) is the theory of the strong interaction, explaining (for example) the binding of three almost massless quarks into a much heavier proton or neutron--and thus most of the mass of the visible Universe. The standard model of particle physics predicts a QCD-related transition that is relevant for the evolution of the early Universe. At low temperatures, the dominant degrees of freedom are colourless bound states of hadrons (such as protons and pions). However, QCD is asymptotically free, meaning that at high energies or temperatures the interaction gets weaker and weaker, causing hadrons to break up. This behaviour underlies the predicted cosmological transition between the low-temperature hadronic phase and a high-temperature quark-gluon plasma phase (for simplicity, we use the word 'phase' to characterize regions with different dominant degrees of freedom). Despite enormous theoretical effort, the nature of this finite-temperature QCD transition (that is, first-order, second-order or analytic crossover) remains ambiguous. Here we determine the nature of the QCD transition using computationally demanding lattice calculations for physical quark masses. Susceptibilities are extrapolated to vanishing lattice spacing for three physical volumes, the smallest and largest of which differ by a factor of five. This ensures that a true transition should result in a dramatic increase of the susceptibilities. No such behaviour is observed: our finite-size scaling analysis shows that the finite-temperature QCD transition in the hot early Universe was not a real phase transition, but an analytic crossover (involving a rapid change, as opposed to a jump, as the temperature varied). As such, it will be difficult to find experimental evidence of this transition from astronomical observations. PMID:17035999

Aoki, Y; Endrodi, G; Fodor, Z; Katz, S D; Szabó, K K

2006-10-12

10

Teaching Quantum Physics Conceptually

Although quantum physics and relativity have been our basis for understanding the universe for the past century, most introductory physics courses still nearly exclude them. This talk presents ways of teaching quantum physics conceptually, i.e. without algebra. Such an approach is appropriate not only for non-scientists but also as an introduction to quantum physics for scientists. Topics will include the

Art Hobson

2002-01-01

11

Open Source Physics: Quantum Spins

NSDL National Science Digital Library

OSP Spins is an interactive computer program that simulates Stern-Gerlach-type measurements on spin-1/2 and spin-1 particles. This package provides the user with a sequence of tutorials and exercises to help them explore the physics of quantum spin. Fundamental issues such as incompatible observables, eigenstate expansions, interference, and quantum dynamics are included.

Christian, Wolfgang

2010-08-12

12

ERIC Educational Resources Information Center

Discusses a teaching strategy for introducing quantum ideas into the school classroom using modern devices. Develops the concepts of quantization, wave-particle duality, nonlocality, and tunneling. (JRH)

Lawrence, I.

1996-01-01

13

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2658 new measurements from 644 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 112 reviews are many that are new or heavily revised including those on Heavy-Quark and Soft-Collinear Effective Theory, Neutrino Cross Section Measurements, Monte Carlo Event Generators, Lattice QCD, Heavy Quarkonium Spectroscopy, Top Quark, Dark Matter, V{sub cb} & V{sub ub}, Quantum Chromodynamics, High-Energy Collider Parameters, Astrophysical Constants, Cosmological Parameters, and Dark Matter. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov.

Beringer, Juerg

2012-07-16

14

TEACHING PHYSICS: Teaching particle physics

NASA Astrophysics Data System (ADS)

Particle physics attracts many students who hear of news from CERN or elsewhere in the media. This article examines which current A-level syllabuses include which bits of particle physics and surveys the many different types of resource available to teachers and students.

Hanley, Phil

2000-09-01

15

NSDL National Science Digital Library

This is a set of interactive Java applets illustrating various aspects of quantum physics through simulations and animations. It is part of an ongoing effort for developing a fully interactive quantum-physics class. It stresses conceptual and qualitative understanding of the topics. Both French and English versions are available.

Joffre, Manuel

2003-10-10

16

Quantum physics and biology have long been regarded as unrelated disciplines, describing nature at the inanimate microlevel on the one hand and living species on the other hand. Over the past decades the life sciences have succeeded in providing ever more and refined explanations of macroscopic phenomena that were based on an improved understanding of molecular structures and mechanisms. Simultaneously, quantum physics, originally rooted in a world-view of quantum coherences, entanglement, and other nonclassical effects, has been heading toward systems of increasing complexity. The present perspective article shall serve as a “pedestrian guide” to the growing interconnections between the two fields. We recapitulate the generic and sometimes unintuitive characteristics of quantum physics and point to a number of applications in the life sciences. We discuss our criteria for a future “quantum biology,” its current status, recent experimental progress, and also the restrictions that nature imposes on bold extrapolations of quantum theory to macroscopic phenomena.

Arndt, Markus; Juffmann, Thomas; Vedral, Vlatko

2009-01-01

17

Studies in theoretical particle physics

This report focuses on research on three distinct areas of particle physics: Chiral Fermions on the Lattice; Weak Scale Baryogenesis; analysis of parity violating nuclear forces, and other an attempt to render the electric dipole moment of the neutron immune from quantum gravity corrections.

Kaplan, D.B.

1992-08-01

18

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2633 new measurements from 689 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed

W.-M. Yao; C. Amsler; D. Asner; R. M. Barnett; J. Beringer; P. R. Burchat; C. D. Carone; C. Caso; O. Dahl; G. D'Ambrosio; A. De Gouvea; M. Doser; S. Eidelman; J. L. Feng; T. Gherghetta; M. Goodman; C. Grab; D. E. Groom; A. Gurtu; K. Hagiwara; K. G. Hayes; J. J. Hernández-Rey; K. Hikasa; H. Jawahery; C. Kolda; Y. Kwon; M. L. Mangano; A. V. Manohar; A. Masoni; R. Miquel; K. Mönig; H. Murayama; K. Nakamura; S. Navas; K. A. Olive; L. Pape; C. Patrignani; A. Piepke; G. Punzi; G. Raffelt; J. G. Smith; M. Tanabashi; J. Terning; N. A. Törnqvist; T. G. sTrippe; P. Vogel; T. Watari; C. G. Wohl; R. L. Workman; P. A. Zyla; B. Armstrong; G. Harper; V. S. Lugovsky; P. Schaffner; M. Artuso; K. S. Babu; H. R. Band; E. Barberio; M. Battaglia; H. Bichsel; O. Biebel; P. Bloch; E. Blucher; R. N. Cahn; D. Casper; A. Cattai; A. Ceccucci; D. Chakraborty; R. S. Chivukula; G. Cowan; T. Damour; T. DeGrand; K. Desler; M. A. Dobbs; M. Drees; A. Edwards; D. A. Edwards; V. D. Elvira; J. Erler; V. V. Ezhela; W. Fetscher; B. D. Fields; B. Foster; D. Froidevaux; T. K. Gaisser; L. Garren; H.-J. Gerber; G. Gerbier; L. Gibbons; F. J. Gilman; G. F. Giudice; A. V. Gritsan; M. Grünewald; H. E. Haber; C. Hagmann; I. Hinchliffe; A. Höcker; P. Igo-Kemenes; J. D. JAckson; K. F. Johnson; D. Karlen; B. Kayser; D. Kirkby; S. R. Klein; K. Kleinknecht; I. G. Knowles; R. V. Kowalewski; P. Kreitz; B. Kursche; Yu. V. Kuyanov; O. Lahav; P. Langacker; A. Liddle; Z. Ligeti; T. M. Liss; L. Littenberg; J. C. Liu; K. S. Lugovsky; s. B. Lugovsky; T. Mannel; D. M. Manley; W. J. Marciano; A. D. Martin; D. Milstead; M. Narain; P. Nason; Y. Nir; J. A. Peacock; S. A. Prell; A. Quadt; S. Raby; B. N. Ratcliff; E. A. Razuvaev; B. Renk; P. Richardson; S. Roesler; G. Rolandi; M. T. Ronan; L. J. Rosenberg; C. T. Sachrajda; Y. Sakai; S. Sarkar; M. Schmitt; O. Schneider; D. Scott; T. Sjöstrand; G. F. Smoot; P. Sokolsky; S. Spanier; H. Spieler; A. Stahl; T. Stanev; R. E. Streitmatter; T. Sumiyoshi; N. P. Tkachenko; G. H. Trilling; G. Valencia; K. van Bibber; M. G. Vincter; D. R. Ward; B. R. Webber; J. D. Wells; M. Whalley; L. Wolfenstsein; J. Womersley; C. L. Woody; A. Yamamoto; O. V. Zenin; J. Zhang; R.-Y. Zhu

2006-01-01

19

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2778 new measurements from 645 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed

C. Amsler; M. Doser; M. Antonelli; D. M. Asner; K. S. Babu; H. Baer; H. R. Band; R. M. Barnett; E. Bergren; J. Beringer; G. Bernardi; W. Bertl; H. Bichsel; O. Biebel; P. Bloch; E. Blucher; S. Blusk; R. N. Cahn; M. Carena; C. Caso; A. Ceccucci; D. Chakraborty; M.-C. Chen; R. S. Chivukula; G. Cowan; O. Dahl; G. D'Ambrosio; T. Damour; A. de Gouvêa; T. DeGrand; B. Dobrescu; M. Drees; D. A. Edwards; S. Eidelman; V. D. Elvira; J. Erler; V. V. Ezhela; J. L. Feng; W. Fetscher; B. D. Fields; B. Foster; T. K. Gaisser; L. Garren; H.-J. Gerber; G. Gerbier; T. Gherghetta; G. F. Giudice; M. Goodman; C. Grab; A. V. Gritsan; J.-F. Grivaz; D. E. Groom; M. Grünewald; A. Gurtu; T. Gutsche; H. E. Haber; K. Hagiwara; C. Hagmann; K. G. Hayes; J. J. Hernández-Rey; K. Hikasa; I. Hinchliffe; A. Höcker; J. Huston; P. Igo-Kemenes; J. D. Jackson; K. F. Johnson; T. Junk; D. Karlen; B. Kayser; D. Kirkby; S. R. Klein; I. G. Knowles; C. Kolda; R. V. Kowalewski; P. Kreitz; B. Krusche; Yu. V. Kuyanov; Y. Kwon; O. Lahav; P. Langacker; A. Liddle; Z. Ligeti; C.-J. Lin; T. M. Liss; L. Littenberg; J. C. Liu; K. S. Lugovsky; H. Mahlke; M. L. Mangano; T. Mannel; A. V. Manohar; W. J. Marciano; A. D. Martin; A. Masoni; D. Milstead; R. Miquel; K. Mönig; H. Murayama; K. Nakamura; M. Narain; P. Nason; S. Navas; P. Nevski; Y. Nir; K. A. Olive; L. Pape; C. Patrignani; J. A. Peacock; G. Punzi; A. Quadt; S. Raby; G. Raffelt; B. N. Ratcliff; B. Renk; P. Richardson; S. Roesler; A. Romaniouk; L. J. Rosenberg; C. T. Sachrajda; Y. Sakai; S. Sarkar; F. Sauli; O. Schneider; D. Scott; W. G. Seligman; M. H. Shaevitz; T. Sjöstrand; J. G. Smith; S. Spanier; H. Spieler; A. Stahl; T. Stanev; S. L. Stone; T. Sumiyoshi; M. Tanabashi; J. Terning; M. Titov; N. P. Tkachenko; N. A. Törnqvist; D. Tovey; G. H. Trilling; T. G. Trippe; G. Valencia; K. van Bibber; M. G. Vincter; P. Vogel; D. R. Ward; T. Watari; B. R. Webber; G. Weiglein; J. D. Wells; M. Whalley; A. Wheeler; C. G. Wohl; L. Wolfenstein; J. Womersley; C. L. Woody; R. L. Workman; A. Yamamoto; W.-M. Yao; O. V. Zenin; J. Zhang; R.-Y. Zhu; P. A. Zyla; G. Harper; V. S. Lugovsky; P. Schaffner

2008-01-01

20

ERIC Educational Resources Information Center

Describes the way in which quantum ideas are incorporated into the Nuffield advanced physics course. Quantum theory is presented as an enormous intellectual leap to be excited by, puzzled over and thought about, not as a set of results and equations to be packed away in the mind. (Author/MLH)

Ogborn, Jon

1974-01-01

21

Measurement in quantum physics.

National Technical Information Service (NTIS)

The conceptual problems in quantum mechanics - including the collapse of the wave functions, the particle-wave duality, the meaning of measurement-arise from the need to ascribe particle character to the wave function, which describes only the wave aspect...

M. Danos T. D. Kieu

1997-01-01

22

Relationships between quantum physics and biology

The known facts of quantum physics and biology strongly suggest the following hypotheses: atoms and the fundamental particles have a rudimentary degree of consciousness, volition, or self-activity; the basic features of quantum mechanics are a result of this fact; the quantum mechanical wave properties of matter are actually the conscious properties of matter; and living organisms are a direct result

Andrew A. Cochran

1971-01-01

23

NASA Astrophysics Data System (ADS)

This biennial review summarizes much of Particle Physics. Using data from previous editions, plus 1900 new measurements from 700 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. ©1996 The American Physical Society.

Barnett, R. M.; Carone, C. D.; Groom, D. E.; Trippe, T. G.; Wohl, C. G.; Armstrong, B.; Gee, P. S.; Wagman, G. S.; James, F.; Mangano, M.; Mönig, K.; Montanet, L.; Feng, J. L.; Murayama, H.; Hernández, J. J.; Manohar, A.; Aguilar-Benitez, M.; Caso, C.; Crawford, R. L.; Roos, M.; Törnqvist, N. A.; Hayes, K. G.; Hagiwara, K.; Nakamura, K.; Tanabashi, M.; Olive, K.; Honscheid, K.; Burchat, P. R.; Shrock, R. E.; Eidelman, S.; Schindler, R. H.; Gurtu, A.; Hikasa, K.; Conforto, G.; Workman, R. L.; Grab, C.; Amsler, C.

1996-07-01

24

Quantum scale of inflation and particle physics of the early universe

The quantum gravitational scale of inflation is calculated by finding a sharp\\u000aprobability peak in the distribution function of chaotic inflationary\\u000acosmologies driven by a scalar field with large negative constant $\\\\xi$ of\\u000anonminimal interaction. In the case of the no-boundary state of the universe\\u000athis peak corresponds to the eternal inflation, while for the tunnelling\\u000aquantum state it generates

A. O. Barvinsky; A. Yu. Kamenshchik

1994-01-01

25

Advanced Level Physics Students' Conceptions of Quantum Physics.

ERIC Educational Resources Information Center

This study addresses questions about particle physics that focus on the nature of electrons. Speculations as to whether they are more like particles or waves or like neither illustrate the difficulties with which students are confronted when trying to incorporate the concepts of quantum physics into their overall conceptual framework. Such…

Mashhadi, Azam

26

Mathematical identities called Maxwellian decompositions give position probability densities of Schrodinger bound states as superpositions of position probability densities for motions in appropriate classical orbits. Hence wave functions are seen as envelopes of motion of quantum particles under random bombardment by an underlying kinetic \\

Alan McCone

2000-01-01

27

Quantum Properties of Fluids and Solids, Physics and Interacting Particles and Fields.

National Technical Information Service (NTIS)

The report provides a summary of the research progress and activities for the period from 1 June 1971 to 30 June 1973. Research was carried out in the following areas: Intermediate Energy Physics - Semi-leptonic weak and electromagnetic interactions with ...

A. L. Fetter J. D. Walecka

1973-01-01

28

If one starts from de Broglie's basic relativistic assumptions, i.e., that all particles have an intrinsic real internal vibration in their rest frame, i.e., hv\\u000a0\\u000a=m\\u000a0\\u000ac\\u000a2\\u000a; that when they are at any one point in space-time the phase of this vibration cannot depend on the choice of the reference frame, then, one can show (following

Ph. Gueret; J.-P. Vigier

1982-01-01

29

Foundations of quantum physics

An enquiry is made on a more fundamental level about the origin of the superposition principle and thus to justify the use of Hilbert space without appeal at the outset to the notion of probability. In doing so there was also a search made for a more general formulation of quantum physics to avoid the apparent paradox of the usual

C. Piron

1976-01-01

30

Quantum physics and biology have long been regarded as unrelated disciplines, describing nature at the inanimate microlevel on the one hand and living species on the other hand. Over the last decades the life sciences have succeeded in providing ever more and refined explanations of macroscopic phenomena that were based on an improved understanding of molecular structures and mechanisms. Simultaneously,

Markus Arndt; Thomas Juffmann; Vlatko Vedral

2009-01-01

31

This is the final report for the Department of Energy Grant to Principal Investigators in Experimental and Theoretical Particle Physics at Boston University. The research performed was in the Energy Frontier at the LHC, the Intensity Frontier at Super-Kamiokande and T2K, the Cosmic Frontier and detector R&D in dark matter detector development, and in particle theory.

Kearns, Edward [Boston Universiy] [Boston Universiy

2013-07-12

32

Particle Physics seeks to identify the elementary consti- tuents of nature and to discover the fundamental forces acting between these constituents. Ordinary matter and non-gra- vitational interactions are described by the Standard Model which comprises two kinds of matter particles (quarks and leptons), three fundamental forces (the strong, electromag- netic and weak interactions) and the Higgs sector as the ori-

H. Pichl; R. Rosenfelder; M. Spira; R. Unterdorfer; J. Urban; M. Walser; L. Wieders; M. Weber

33

NSDL National Science Digital Library

This Fermilab website offers physicists the chance to educate individuals about the "fundamental particles and forces of our universe." The website offers a database containing over 250 hands-on activities, special events, research participation, and other educational and outreach programs. The information can be searched by state, audience, and institution. The database offers a brief description of each program and a link to its website. Students can learn about the basics of particle physics through a concise article. Educators can discover why particle physics education is important.

34

Quantum Mechanics and physical calculations

NASA Astrophysics Data System (ADS)

We suggest to realize the computer simulation and calculation by the algebraic structure built on the basis of the logic inherent to processes in physical systems (called physical computing). We suggest a principle for the construction of quantum algorithms of neuroinformatics of quantum neural networks. The role of academician Sahakyan is emphasized in the development of quantum physics in Armenia.

Karayan, H. S.

2014-03-01

35

Cosmology and Particle Physics

NASA Astrophysics Data System (ADS)

The cosmic connections between physics on the very largest and very smallest scales are reviewed with an emphasis on the symbiotic relation between elementary particle physics and cosmology. After a review of the early Universe as a cosmic accelerator, various cosmological and astrophysical constraints on models of particle physics are outlined. To illustrate this approach to particle physics via cosmology, reference is made to several areas of current research: baryon non-conservation and baryon asymmetry; free quarks, heavy hadrons and other exotic relics; primordial nucleosynthesis and neutrino masses. In the last few years we have witnessed the birth and growth to healthy adolescence of a new collaboration between astrophysicists and particle physicists. The most notable success of this cooperative effort has been to provide the framework for understanding, within the context of GUTs and the hot big-bang cosmology, the universal baryon asymmetry. The most exciting new predictions this effort has spawned are that exotic relics may exist in detectable abundances. In particular, we may live in a neutrino-dominated Universe. In the next few years, accummulating laboratory data (for example proton decay, neutrino masses and oscillations) coupled with theoritical work in particle physics and cosmology will ensure the growth to maturity of this joint effort.

Steigman, G.

1982-01-01

36

NASA Astrophysics Data System (ADS)

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2158 new measurements from 551 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 108 reviews are many that are new or heavily revised including those on neutrino mass, mixing, and oscillations, QCD, top quark, CKM quark-mixing matrix, Vud & Vus, Vcb & Vub, fragmentation functions, particle detectors for accelerator and non-accelerator physics, magnetic monopoles, cosmological parameters, and big bang cosmology. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: pdg.lbl.gov.

Nakamura, K.; Particle Data Group

2010-07-01

37

Physical Constructivism and Quantum Probability

NASA Astrophysics Data System (ADS)

I describe the main ideas of constructive physics and its role for the probability interpretation of quantum theory. It is shown how the explicit probability space for quantum systems gives the formal representation of entanglement and decoherence.

Ozhigov, Yu. I.

2009-03-01

38

NASA Astrophysics Data System (ADS)

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2778 new measurements from 645 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 108 reviews are many that are new or heavily revised including those on CKM quark-mixing matrix, Vud &Vus, Vcb &Vub, top quark, muon anomalous magnetic moment, extra dimensions, particle detectors, cosmic background radiation, dark matter, cosmological parameters, and big bang cosmology. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov.

Particle Data Group; Amsler, C.; Doser, M.; Antonelli, M.; Asner, D. M.; Babu, K. S.; Baer, H.; Band, H. R.; Barnett, R. M.; Bergren, E.; Beringer, J.; Bernardi, G.; Bertl, W.; Bichsel, H.; Biebel, O.; Bloch, P.; Blucher, E.; Blusk, S.; Cahn, R. N.; Carena, M.; Caso, C.; Ceccucci, A.; Chakraborty, D.; Chen, M.-C.; Chivukula, R. S.; Cowan, G.; Dahl, O.; D'Ambrosio, G.; Damour, T.; de Gouvêa, A.; Degrand, T.; Dobrescu, B.; Drees, M.; Edwards, D. A.; Eidelman, S.; Elvira, V. D.; Erler, J.; Ezhela, V. V.; Feng, J. L.; Fetscher, W.; Fields, B. D.; Foster, B.; Gaisser, T. K.; Garren, L.; Gerber, H.-J.; Gerbier, G.; Gherghetta, T.; Giudice, G. F.; Goodman, M.; Grab, C.; Gritsan, A. V.; Grivaz, J.-F.; Groom, D. E.; Grünewald, M.; Gurtu, A.; Gutsche, T.; Haber, H. E.; Hagiwara, K.; Hagmann, C.; Hayes, K. G.; Hernández-Rey, J. J.; Hikasa, K.; Hinchliffe, I.; Höcker, A.; Huston, J.; Igo-Kemenes, P.; Jackson, J. D.; Johnson, K. F.; Junk, T.; Karlen, D.; Kayser, B.; Kirkby, D.; Klein, S. R.; Knowles, I. G.; Kolda, C.; Kowalewski, R. V.; Kreitz, P.; Krusche, B.; Kuyanov, Yu. V.; Kwon, Y.; Lahav, O.; Langacker, P.; Liddle, A.; Ligeti, Z.; Lin, C.-J.; Liss, T. M.; Littenberg, L.; Liu, J. C.; Lugovsky, K. S.; Lugovsky, S. B.; Mahlke, H.; Mangano, M. L.; Mannel, T.; Manohar, A. V.; Marciano, W. J.; Martin, A. D.; Masoni, A.; Milstead, D.; Miquel, R.; Mönig, K.; Murayama, H.; Nakamura, K.; Narain, M.; Nason, P.; Navas, S.; Nevski, P.; Nir, Y.; Olive, K. A.; Pape, L.; Patrignani, C.; Peacock, J. A.; Piepke, A.; Punzi, G.; Quadt, A.; Raby, S.; Raffelt, G.; Ratcliff, B. N.; Renk, B.; Richardson, P.; Roesler, S.; Rolli, S.; Romaniouk, A.; Rosenberg, L. J.; Rosner, J. L.; Sachrajda, C. T.; Sakai, Y.; Sarkar, S.; Sauli, F.; Schneider, O.; Scott, D.; Seligman, W. G.; Shaevitz, M. H.; Sjöstrand, T.; Smith, J. G.; Smoot, G. F.; Spanier, S.; Spieler, H.; Stahl, A.; Stanev, T.; Stone, S. L.; Sumiyoshi, T.; Tanabashi, M.; Terning, J.; Titov, M.; Tkachenko, N. P.; Törnqvist, N. A.; Tovey, D.; Trilling, G. H.; Trippe, T. G.; Valencia, G.; van Bibber, K.; Vincter, M. G.; Vogel, P.; Ward, D. R.; Watari, T.; Webber, B. R.; Weiglein, G.; Wells, J. D.; Whalley, M.; Wheeler, A.; Wohl, C. G.; Wolfenstein, L.; Womersley, J.; Woody, C. L.; Workman, R. L.; Yamamoto, A.; Yao, W.-M.; Zenin, O. V.; Zhang, J.; Zhu, R.-Y.; Zyla, P. A.; Harper, G.; Lugovsky, V. S.; Schaffner, P.

2008-09-01

39

NASA Astrophysics Data System (ADS)

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2778 new measurements from 645 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 108 reviews are many that are new or heavily revised including those on CKM quark-mixing matrix, V ud & V us, V cb & V ub, top quark, muon anomalous magnetic moment, extra dimensions, particle detectors, cosmic background radiation, dark matter, cosmological parameters, and big bang cosmology. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov.

Amsler, C.; Doser, M.; Antonelli, M.; Asner, D. M.; Babu, K. S.; Baer, H.; Band, H. R.; Barnett, R. M.; Bergren, E.; Beringer, J.; Bernardi, G.; Bertl, W.; Bichsel, H.; Biebel, O.; Bloch, P.; Blucher, E.; Blusk, S.; Cahn, R. N.; Carena, M.; Caso, C.; Ceccucci, A.; Chakraborty, D.; Chen, M.-C.; Chivukula, R. S.; Cowan, G.; Dahl, O.; D'Ambrosio, G.; Damour, T.; de Gouvêa, A.; DeGrand, T.; Dobrescu, B.; Drees, M.; Edwards, D. A.; Eidelman, S.; Elvira, V. D.; Erler, J.; Ezhela, V. V.; Feng, J. L.; Fetscher, W.; Fields, B. D.; Foster, B.; Gaisser, T. K.; Garren, L.; Gerber, H.-J.; Gerbier, G.; Gherghetta, T.; Giudice, G. F.; Goodman, M.; Grab, C.; Gritsan, A. V.; Grivaz, J.-F.; Groom, D. E.; Grünewald, M.; Gurtu, A.; Gutsche, T.; Haber, H. E.; Hagiwara, K.; Hagmann, C.; Hayes, K. G.; Hernández-Rey, J. J.; Hikasa, K.; Hinchliffe, I.; Höcker, A.; Huston, J.; Igo-Kemenes, P.; Jackson, J. D.; Johnson, K. F.; Junk, T.; Karlen, D.; Kayser, B.; Kirkby, D.; Klein, S. R.; Knowles, I. G.; Kolda, C.; Kowalewski, R. V.; Kreitz, P.; Krusche, B.; Kuyanov, Yu. V.; Kwon, Y.; Lahav, O.; Langacker, P.; Liddle, A.; Ligeti, Z.; Lin, C.-J.; Liss, T. M.; Littenberg, L.; Liu, J. C.; Lugovsky, K. S.; Lugovsky, S. B.; Mahlke, H.; Mangano, M. L.; Mannel, T.; Manohar, A. V.; Marciano, W. J.; Martin, A. D.; Masoni, A.; Milstead, D.; Miquel, R.; Mönig, K.; Murayama, H.; Nakamura, K.; Narain, M.; Nason, P.; Navas, S.; Nevski, P.; Nir, Y.; Olive, K. A.; Pape, L.; Patrignani, C.; Peacock, J. A.; Piepke, A.; Punzi, G.; Quadt, A.; Raby, S.; Raffelt, G.; Ratcliff, B. N.; Renk, B.; Richardson, P.; Roesler, S.; Rolli, S.; Romaniouk, A.; Rosenberg, L. J.; Rosner, J. L.; Sachrajda, C. T.; Sakai, Y.; Sarkar, S.; Sauli, F.; Schneider, O.; Scott, D.; Seligman, W. G.; Shaevitz, M. H.; Sjöstrand, T.; Smith, J. G.; Smoot, G. F.; Spanier, S.; Spieler, H.; Stahl, A.; Stanev, T.; Stone, S. L.; Sumiyoshi, T.; Tanabashi, M.; Terning, J.; Titov, M.; Tkachenko, N. P.; Törnqvist, N. A.; Tovey, D.; Trilling, G. H.; Trippe, T. G.; Valencia, G.; van Bibber, K.; Vincter, M. G.; Vogel, P.; Ward, D. R.; Watari, T.; Webber, B. R.; Weiglein, G.; Wells, J. D.; Whalley, M.; Wheeler, A.; Wohl, C. G.; Wolfenstein, L.; Womersley, J.; Woody, C. L.; Workman, R. L.; Yamamoto, A.; Yao, W.-M.; Zenin, O. V.; Zhang, J.; Zhu, R.-Y.; Zyla, P. A.; Harper, G.; Lugovsky, V. S.; Schaffner, P.; Particle Data Group

40

NASA Astrophysics Data System (ADS)

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2633 new measurements from 689 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 110 reviews are many that are new or heavily revised including those on CKM quark-mixing matrix, Vud & Vus, Vcb & Vub, top quark, muon anomalous magnetic moment, extra dimensions, particle detectors, cosmic background radiation, dark matter, cosmological parameters, and big bang cosmology. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov.

Yao, W.-M.; Amsler, C.; Asner, D.; Barnett, R. M.; Beringer, J.; Burchat, P. R.; Carone, C. D.; Caso, C.; Dahl, O.; D'Ambrosio, G.; De Gouvea, A.; Doser, M.; Eidelman, S.; Feng, J. L.; Gherghetta, T.; Goodman, M.; Grab, C.; Groom, D. E.; Gurtu, A.; Hagiwara, K.; Hayes, K. G.; Hernández-Rey, J. J.; Hikasa, K.; Jawahery, H.; Kolda, C.; Kwon, Y.; Mangano, M. L.; Manohar, A. V.; Masoni, A.; Miquel, R.; Mönig, K.; Murayama, H.; Nakamura, K.; Navas, S.; Olive, K. A.; Pape, L.; Patrignani, C.; Piepke, A.; Punzi, G.; Raffelt, G.; Smith, J. G.; Tanabashi, M.; Terning, J.; Törnqvist, N. A.; sTrippe, T. G.; Vogel, P.; Watari, T.; Wohl, C. G.; Workman, R. L.; Zyla, P. A.; Armstrong, B.; Harper, G.; Lugovsky, V. S.; Schaffner, P.; Artuso, M.; Babu, K. S.; Band, H. R.; Barberio, E.; Battaglia, M.; Bichsel, H.; Biebel, O.; Bloch, P.; Blucher, E.; Cahn, R. N.; Casper, D.; Cattai, A.; Ceccucci, A.; Chakraborty, D.; Chivukula, R. S.; Cowan, G.; Damour, T.; DeGrand, T.; Desler, K.; Dobbs, M. A.; Drees, M.; Edwards, A.; Edwards, D. A.; Elvira, V. D.; Erler, J.; Ezhela, V. V.; Fetscher, W.; Fields, B. D.; Foster, B.; Froidevaux, D.; Gaisser, T. K.; Garren, L.; Gerber, H.-J.; Gerbier, G.; Gibbons, L.; Gilman, F. J.; Giudice, G. F.; Gritsan, A. V.; Grünewald, M.; Haber, H. E.; Hagmann, C.; Hinchliffe, I.; Höcker, A.; Igo-Kemenes, P.; JAckson, J. D.; Johnson, K. F.; Karlen, D.; Kayser, B.; Kirkby, D.; Klein, S. R.; Kleinknecht, K.; Knowles, I. G.; Kowalewski, R. V.; Kreitz, P.; Kursche, B.; Kuyanov, Yu. V.; Lahav, O.; Langacker, P.; Liddle, A.; Ligeti, Z.; Liss, T. M.; Littenberg, L.; Liu, J. C.; Lugovsky, K. S.; Lugovsky, s. B.; Mannel, T.; Manley, D. M.; Marciano, W. J.; Martin, A. D.; Milstead, D.; Narain, M.; Nason, P.; Nir, Y.; Peacock, J. A.; Prell, S. A.; Quadt, A.; Raby, S.; Ratcliff, B. N.; Razuvaev, E. A.; Renk, B.; Richardson, P.; Roesler, S.; Rolandi, G.; Ronan, M. T.; Rosenberg, L. J.; Sachrajda, C. T.; Sakai, Y.; Sarkar, S.; Schmitt, M.; Schneider, O.; Scott, D.; Sjöstrand, T.; Smoot, G. F.; Sokolsky, P.; Spanier, S.; Spieler, H.; Stahl, A.; Stanev, T.; Streitmatter, R. E.; Sumiyoshi, T.; Tkachenko, N. P.; Trilling, G. H.; Valencia, G.; van Bibber, K.; Vincter, M. G.; Ward, D. R.; Webber, B. R.; Wells, J. D.; Whalley, M.; Wolfenstsein, L.; Womersley, J.; Woody, C. L.; Yamamoto, A.; Zenin, O. V.; Zhang, J.; Zhu, R.-Y.

2006-07-01

41

Increasing complexity with quantum physics.

We argue that complex systems science and the rules of quantum physics are intricately related. We discuss a range of quantum phenomena, such as cryptography, computation and quantum phases, and the rules responsible for their complexity. We identify correlations as a central concept connecting quantum information and complex systems science. We present two examples for the power of correlations: using quantum resources to simulate the correlations of a stochastic process and to implement a classically impossible computational task. PMID:21974665

Anders, Janet; Wiesner, Karoline

2011-09-01

42

Increasing complexity with quantum physics

NASA Astrophysics Data System (ADS)

We argue that complex systems science and the rules of quantum physics are intricately related. We discuss a range of quantum phenomena, such as cryptography, computation and quantum phases, and the rules responsible for their complexity. We identify correlations as a central concept connecting quantum information and complex systems science. We present two examples for the power of correlations: using quantum resources to simulate the correlations of a stochastic process and to implement a classically impossible computational task.

Anders, Janet; Wiesner, Karoline

2011-09-01

43

Particle physics -- Future directions

Wonderful opportunities await particle physics over the next decade, with the coming of the Large Hadron Collider at CERN to explore the 1-TeV scale (extending efforts at LEP and the Tevatron to unravel the nature of electroweak symmetry breaking) and many initiatives to develop our understanding of the problem of identity: what makes a neutrino a neutrino and a top quark a top quark. Here I have in mind the work of the B factories and the Tevatron collider on CP violation and the weak interactions of the b quark; the wonderfully sensitive experiments at Brookhaven, CERN, Fermilab, and Frascati on CP violation and rare decays of kaons; the prospect of definitive accelerator experiments on neutrino oscillations and the nature of the neutrinos; and a host of new experiments on the sensitivity frontier. We might even learn to read experiment for clues about the dimensionality of spacetime. If we are inventive enough, we may be able to follow this rich menu with the physics opportunities offered by a linear collider and a (muon storage ring) neutrino factory. I expect a remarkable flowering of experimental particle physics, and of theoretical physics that engages with experiment. I describe some of the great questions before us and the challenges of providing the instruments that will be needed to define them more fully and eventually to answer them.

Chris Quigg

2001-11-29

44

Detecting the relative localisation of quantum particles

NASA Astrophysics Data System (ADS)

One interpretation of how the classical world emerges from quantum physics involves the build-up of certain robust entangled states between particles due to scattering events [1]. This is intriguing because it links classical behaviour with the uniquely quantum effect of entanglement and differs from other interpretations that say classicality arises when quantum correlations are lost or neglected in measurements. However, the problem with this new interpretation has been finding an experimental way of verifying it. Here we outline a straightforward scheme that enables just that and should, in principle, allow experiments to confirm the theory to any desired degree of accuracy.

Knott, P. A.; Sindt, J.; Dunningham, J. A.

2013-06-01

45

Cosmology and particle physics

NASA Technical Reports Server (NTRS)

The interplay between cosmology and elementary particle physics is discussed. The standard cosmology is reviewed, concentrating on primordial nucleosynthesis and discussing how the standard cosmology has been used to place constraints on the properties of various particles. Baryogenesis is discussed, showing how a scenario in which the B-, C-, and CP-violating interactions in GUTs provide a dynamical explanation for the predominance of matter over antimatter and for the present baryon-to-photon ratio. It is shown how the very early dynamical evolution of a very weakly coupled scalar field which is initially displaced from the minimum of its potential may explain a handful of very fundamental cosmological facts which are not explained by the standard cosmology.

Turner, Michael S.

1988-01-01

46

Elementary Particles and the Laws of Physics

NASA Astrophysics Data System (ADS)

Developing a theory that seamlessly combines relativity and quantum mechanics, the most important conceptual breakthroughs in twentieth century physics, has proved to be a difficult and ongoing challenge. This book details how two distinguished physicists and Nobel laureates have explored this theme in two lectures given in Cambridge, England, in 1986 to commemorate the famous British physicist Paul Dirac. Given for nonspecialists and undergraduates, the talks transcribed in Elementary Particles and the Laws of Physics focus on the fundamental problems of physics and the present state of our knowledge. Professor Feynman examines the nature of antiparticles, and in particular the relationship between quantum spin and statistics. Professor Weinberg speculates on how Einstein's theory of gravitation might be reconciled with quantum theory in the final law of physics. Highly accessible, deeply thought provoking, this book will appeal to all those interested in the development of modern physics.

Feynman, Richard P.; Weinberg, Steven

1987-11-01

47

Quantum Algorithms: Applicable Algebra and Quantum Physics

NASA Astrophysics Data System (ADS)

Classical computer science relies on the concept of Turing machines as a unifying model of universal computation. According to the modern Church-Turing Thesis, this concept is interpreted in the form that every physically reasonable model of computation can be efficiently simulated on a probabilistic Turing machine. Recently this understanding, which was taken for granted for a long time, has required a severe reorientation because of the emergence of new computers that do not rely on classical physics but, rather, use effects predicted by quantum mechanics.Quantum algorithms benefit from the application of the superposition principle to the internal states of the quantum computer, which are considered to be states in a (finite-dimensional) Hilbert space. As a result, these algorithms lead to a new theory of computation and might be of central importance to physics and computer science.We shall introduce the complexity model of quantum gates, which are most familiar to researchers in the field of quantum computing, and shall give many examples of the usefulness and conciseness of this formalism. Quantum circuits provide a computational model equivalent to quantum Turing machines.

Beth, Thomas; Roetteler, Martin

48

Studies in theoretical particle physics. Progress report

This report focuses on research on three distinct areas of particle physics: Chiral Fermions on the Lattice; Weak Scale Baryogenesis; analysis of parity violating nuclear forces, and other an attempt to render the electric dipole moment of the neutron immune from quantum gravity corrections.

Kaplan, D.B.

1992-08-01

49

Physics 219: Quantum Computation

NSDL National Science Digital Library

This is the course web page for an undergraduate Quantum Computation course at Caltech. A course outline, extensive lecture notes, and homework sets, some with solutions, are provided. Links to recent versions of the course are included. There are also links to important references and other web resources in quantum information theory and quantum computation.

Preskill, John

2005-04-16

50

Particle physics---Experimental

We are continuing a research program in particle astrophysics and high energy experimental particle physics. We have joined the DUMAND Collaboration, which is constructing a deep undersea astrophysical neutrino detector near Hawaii. Studies of high energy hadronic interactions using emulsion chamber techniques were also continued, using balloon flight exposures to ultra-high cosmic ray nuclei (JACEE) and accelerator beams. As members of the DUMAND Collaboration, we have responsibility for development a construction of critical components for the deep undersea neutrino detector facility. We have designed and developed the acoustical positioning system required to permit reconstruction of muon tracks with sufficient precision to meet the astrophysical goals of the experiment. In addition, we are making significant contributions to the design of the database and triggering system to be used. Work has been continuing in other aspects of the study of multiparticle production processes in nuclei. We are participants in a joint US/Japan program to study nuclear interactions at energies two orders of magnitude greater than those of existing accelerators, using balloon-borne emulsion chambers. On one of the flights we found two nuclear interactions of multiplicity over 1000 -- one with a multiplicity of over 2000 and pseudorapidity density {approximately} 800 in the central region. At the statistical level of the JACEE experiment, the frequency of occurrence of such events is orders of magnitude too large. We have continued our ongoing program to study hadronic interactions in emulsions exposed to high energy accelerator beams.

Lord, J.J.; Boynton, P.E.; Burnett, T.H.; Wilkes, R.J.

1991-08-21

51

Statistical Issues in Particle Physics

NASA Astrophysics Data System (ADS)

This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '4.5 Statistical Issues in Particle Physics' of Chapter '4 Data Treatment and Analysis Methods' with the content:

Lyons, L.

52

Student Perspectives in Quantum Physics

NSDL National Science Digital Library

Introductory courses in classical physics are promoting in students a realist perspective, made up in part by the belief that all physical properties of a system can be simultaneously specified, and thus determined at all future times. Such a perspective can be problematic for introductory quantum physics students, who must develop new framings of epistemic and ontological resources in order to properly interpret what it means to have knowledge of quantum systems. We document this evolution in student thinking in part through pre/post instruction evaluations using the CLASS attitude survey. We further characterize variations in student epistemic and ontological commitments by examining responses to an essay question, coupled with responses to supplemental quantum attitude statements. We find that, after instruction in modern physics, many students are still exhibiting a realist perspective in contexts where a quantum perspective is needed. We also find that this effect can be significantly influenced by instruction, where we observe variations for courses with differing learning goals.

Baily, Charles; Finkelstein, Noah D.

2008-09-15

53

Topology change and quantum physics.

National Technical Information Service (NTIS)

The role of topology in elementary quantum physics is discussed in detail. It is argued that attributes of classical spatial topology emerge from properties of state vectors with suitably smooth time evolution. Equivalently, they emerge from consideration...

A. P. Balachandran G. Bimonte G. Marmo A. Simoni

1995-01-01

54

Research in elementary particle physics

This report discusses research in the following areas of high energy physics: B meson mixing; CDF response to low energy jets; jet scaling behavior; search for pair produced leptoquarks at CDF; SSC program; quantum field theory; and neural networks. (LSP).

Kirsch, L.E.; Schnitzer, H.J.; Bensinger, J.R.; Blocker, C.A.

1992-01-01

55

Teaching Quantum Physics without Paradoxes

ERIC Educational Resources Information Center

Although the resolution to the wave-particle paradox has been known for 80 years, it is seldom presented. Briefly, the resolution is that material particles and photons are the quanta of extended spatially continuous but energetically quantized fields. But because the resolution resides in quantum field theory and is not usually spelled out in…

Hobson, Art

2007-01-01

56

This tome is a formal presentation of the unsharp observable approach to quantum mechanics using the positive operator valued (POV) concept of an observable. It is intended for philosophers and mathematicians as well as physicists. This is a very formalistic book. There are, however, portions that should be read by all experimentalists performing quantum mechanical studies as well as graduate

J L Safko

1996-01-01

57

Recent theoretical results confirm that quantum theory provides the possibility of new ways of performing efficient calculations. The most striking example is the factoring problem. It has recently been shown that computers that exploit quantum features could factor large composite integers. This task is believed to be out of reach of classical computers as soon as the number of digits

Adriano Barenco

1996-01-01

58

Lithography using quantum entangled particles

NASA Technical Reports Server (NTRS)

A system of etching using quantum entangled particles to get shorter interference fringes. An interferometer is used to obtain an interference fringe. N entangled photons are input to the interferometer. This reduces the distance between interference fringes by n, where again n is the number of entangled photons.

Williams, Colin (Inventor); Dowling, Jonathan (Inventor)

2001-01-01

59

Topics in particle physics phenomenology

NASA Astrophysics Data System (ADS)

Heavy quark physics, spine dependent forces in heavy quark systems, bound state effects in the Upsilon yields gamma + resonance, compatibility of free fractional charge, and Dirac magnetic monopoles are discussed. Using the results of the fourth-order quark-antiquark interactions in perturbative quantum chromodynamics (QCD), the spin dependent potentials in the formalism of Eichten and Feinberg and Gromes have to be generalized to include the quark mass dependence. The recently observed hyperfine and fine structure splittings in the J/Psi and Tau systems are found to agree with the purely perturbative QCD results for the scale parameter. The effect of particle-antiparticle bound state dynamics on the reaction Upsilon yields gamma + resonance were studied. The existence of a free fractionally charged particle together with a monopole that has magnetic charge g = 1/2 e poses an apparent conflict. This conflict may be resolved by enlarging the exact gauge symmetry. The resulting constraint on GUTs is discussed and illustrated with an SU(9) GUT. Under certain assumptions, SU(9) is the smallest group to satisfy the constraints.

Pantaleone, J. T.

1985-12-01

60

Quantum hoop conjecture: Black hole formation by particle collisions

NASA Astrophysics Data System (ADS)

We address the issue of (quantum) black hole formation by particle collision in quantum physics. We start by constructing the horizon wave-function for quantum mechanical states representing two highly boosted non-interacting particles that collide in flat one-dimensional space. From this wave-function, we then derive a probability that the system becomes a black hole as a function of the initial momenta and spatial separation between the particles. This probability allows us to extend the hoop conjecture to quantum mechanics and estimate corrections to its classical counterpart.

Casadio, Roberto; Micu, Octavian; Scardigli, Fabio

2014-05-01

61

Quantum Mechanics and Physical Reality

IN a recent article by A. Einstein, B. Podolsky and N. Rosen, which appeared in the Physical Review of May 15, and was reviewed in NATURE of June 22, the question of the completeness of quantum mechanical description has been discussed on the basis of a ``criterion of physical reality'', which the authors formulate as follows : ``If, without in

N. Bohr

1935-01-01

62

An Introduction to Particle Physics

NSDL National Science Digital Library

The Particle Physics Department at Rutherford Appleton Laboratory (RAL) provides the Introduction to Particle Physics homepage. Particle physics is defined as "the study of the basic elements of matter and the forces acting among them...to determine the fundamental laws that control the make-up of matter and the physical universe." The Introduction provides more information on Accelerators, Detectors, Antimatter, Big Bang Science, and Dark Matter. Further information can be found in The Big Bang and The Top Quark sections, both of which provide images and in-depth summaries. Users can navigate via a contents page or through links at the bottom of the page.

63

Blind Analysis in Particle Physics

NASA Astrophysics Data System (ADS)

A review of the blind analysis technique, as used in particle physics measurements, is presented. The history of blind analyses in physics is briefly discussed. Next the dangers of "experimenter's bias" and the advantages of a blind analysis are described. Three distinct kinds of blind analysis in particle physics are presented in detail. Finally, the BABAR collaboration's experience with the blind analysis technique is discussed.

Roodman, Aaron

64

Quantum information is physical

We discuss a few current developments in the use of quantum mechanically coherent systems for information processing. In each of these developments, Rolf Landauer has played a crucial role in nudging us, and other workers in the field, into asking the right questions, some of which we have been lucky enough to answer. A general overview of the key ideas

David P. DiVincenzo; Daniel Loss

1998-01-01

65

Physics of Particle Acceleration.

National Technical Information Service (NTIS)

The development of particle accelerators was reviewed with regard to energy and cost. The problems of funding much larger and slower particle accelerators was considered. The question of new ideas and techniques was raised and, with this in mind, the vari...

J. D. Lawson

1982-01-01

66

Quantum computation and spin physics (invited)

A brief review is given of the physical implementation of quantum computation within spin systems or other two-state quantum systems. The importance of the controlled-NOT or quantum XOR gate as the fundamental primitive operation of quantum logic is emphasized. Recent developments in the use of quantum entanglement to build error-robust quantum states, and the simplest protocol for quantum error correction, are discussed. {copyright} {ital 1997 American Institute of Physics.}

DiVincenzo, D.P. [IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (United States)] [IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (United States)

1997-04-01

67

Testing Quantum Mechanics in High-Energy Physics

In this set of lectures we show that particle physics can also contribute to fundamental questions about quantum mechanics\\u000a (QM) and even shine new light in the fine workings of quantum physics and this at scales of energies which are not available\\u000a for usual quantum systems. In particular the massive meson–antimeson systems are specially suitable as they offer a unique

Beatrix C. Hiesmayr

68

Quantum Hamiltonian Physics with Supercomputers

NASA Astrophysics Data System (ADS)

The vision of solving the nuclear many-body problem in a Hamiltonian framework with fundamental interactions tied to QCD via Chiral Perturbation Theory is gaining support. The goals are to preserve the predictive power of the underlying theory, to test fundamental symmetries with the nucleus as laboratory and to develop new understandings of the full range of complex quantum phenomena. Advances in theoretical frameworks (renormalization and many-body methods) as well as in computational resources (new algorithms and leadership-class parallel computers) signal a new generation of theory and simulations that will yield profound insights into the origins of nuclear shell structure, collective phenomena and complex reaction dynamics. Fundamental discovery opportunities also exist in such areas as physics beyond the Standard Model of Elementary Particles, the transition between hadronic and quark-gluon dominated dynamics in nuclei and signals that characterize dark matter. I will review some recent achievements and present ambitious consensus plans along with their challenges for a coming decade of research that will build new links between theory, simulations and experiment. Opportunities for graduate students to embark upon careers in the fast developing field of supercomputer simulations is also discussed.

Vary, James P.

2014-06-01

69

Students from six local high schools -- Farmingdale, Sachem East, Shoreham, Smithtown East, Ward Melville, and William Floyd -- came to Brookhaven National Laboratory to experience research with particle physicist Helio Takai. They were among more than 6,

Helio Takai

2009-04-10

70

Students from six local high schools -- Farmingdale, Sachem East, Shoreham, Smithtown East, Ward Melville, and William Floyd -- came to Brookhaven National Laboratory to experience research with particle physicist Helio Takai. They were among more than 6,

Helio Takai

2010-01-08

71

NSDL National Science Digital Library

This web site provides small-group learning materials for teaching wave physics and modern physics to non-science-majors. To match student skills, observation, qualitative analysis, and graphical representations are used to introduce interference, discuss energy and probability, and develop an understanding of bound states, spectroscopy, modeling of molecules, and tunneling.

Wittmann, Michael C.; Morgan, Jeffrey T.

2007-07-20

72

Nonlinear Quantum Plasma Physics

NASA Astrophysics Data System (ADS)

We present simulation studies of the formation and dynamics of dark solitons and vortices, and of nonlinear interactions between intense circularly polarized electromagnetic (CPEM) waves and electron plasma oscillations (EPOs) dense in quantum electron plasmas. The electron dynamics in the latter is governed by a pair of equations comprising the nonlinear Schrödinger and Poisson system of equations, which conserves electrons and their momentum and energy. Nonlinear fluid simulations are carried out to investigate the properties of fully developed two-dimensional (2D) electron fluid turbulence in a dense Fermi (quantum) plasma. We report several distinguished features that have resulted from our 2D computer simulations of the nonlinear equations which govern the dynamics of nonlinearly interacting electron plasma oscillations (EPOs) in the Fermi plasma. We find that a 2D quantum electron plasma exhibits dual cascades, in which the electron number density cascades towards smaller turbulent scales, while the electrostatic potential forms larger scale eddies. The characteristic turbulent spectrum associated with the nonlinear electron plasma oscillations determined critically by quantum tunneling effect. The turbulent transport corresponding to the large-scale potential distribution is predominant in comparison with the small-scale electron number density variation, a result that is consistent with the classical diffusion theory. The dynamics of the CPEM waves is also governed by a nonlinear schrödinger equation, which is nonlinearly coupled with the nonlinear Schrödinger equation of the EPOs via the relativistic ponderomotive force, the relativistic electron mass increase in the CPEM field, and the electron density fluctuations. The present governing equations in one spatial dimension admit stationary solutions in the form a dark envelope soliton. The dynamics of the latter reveals its robustness. Furthermore, we numerically demonstrate the existence of cylindrically symmetric two-dimensional quantum electron vortices, which survive during collisions. The nonlinear equations admit the modulational instability of an intense CPEM pump wave against EPOs, leading to the formation and trapping of localized CPEM wave pipes in the electron density hole that is associated with a positive potential distribution in our dense plasma.

Shukla, Padma K.; Eliasson, Bengt; Shaikh, Dastgeer

73

Quantum structures, separated physical entities and probability

We prove that if the physical entity S consisting of two separated physical entities S1 and S2 satisfies the axioms of orthodox quantum mechanics, then at least one of the two subentities is a classical physical entity. This theorem implies that separated quantum entities cannot be described by quantum mechanics. We formulate this theorem in an approach where physical entities

Diederik Aerts

1994-01-01

74

Survey of general quantum physics

The abstract description of a physical system is developed, along lines originally suggested by Birkhoff and von Neumann, in terms of the complete lattice of propositions associated with that system, and the distinction between classical and quantum systems is made precise. With the help of the notion of state, a propositional system is defined: it is remarked that every irreducible

C. Piron

1972-01-01

75

Machines, logic and quantum physics

Though the truths of logic and pure mathematics are objective and independent of any contingent facts or laws of nature, our knowledge of these truths depends entirely on our knowledge of the laws of physics. Recent progress in the quantum theory of computation has provided practical instances of this, and forces us to abandon the classical view that computation, and

David Deutsch; Artur Ekert; Rossella Lupacchini

2000-01-01

76

Quantum Physics in One Dimension

To a casual ostrich the world of quantum physics in one dimension may sound a little one-dimensional, suitable perhaps for those with an unhealthy obsession for the esoteric. Nothing of course could be further from the truth. The field is remarkably rich and broad, and for more than fifty years has thrown up innumerable challenges. Theorists, realising that the role

David Logan

2004-01-01

77

Particle Physics UK: Strange Nuclei

NSDL National Science Digital Library

This "Picture of the Month" from Particle Physics UK shows an image of the nuclear disintegration that occurs when a nucleus is struck by a particle containing a strange quark. The site includes commentary on the tracks in the reaction. The 1952 discovery in Poland was celebrated on a stamp, a postcard, and a postmark, which are pictured.

2009-12-09

78

Particle Physics and Instrumentation - Physics and Technology

NASA Astrophysics Data System (ADS)

The impact of experimental science is defined by the capabilities of its instruments. Particle Physics, reaching to increasingly small scales, depends on advances both in accelerator and detector technology to explore high energies and rare processes. The importance of Instrumentation to the Particle Physics program has been recognized by the creation of an ``Instrumentation Frontier'' within the 2013 DPF ``Snowmass'' planning process. We give examples of how physics needs have guided development of technologies for the Energy and Intensity Frontiers. We describe how current technology has limited our reach and what new technologies may be on the horizon. We will also discuss the status of the Instrumentation Frontier work in preparation for the Community Summer Study this summer in Minneapolis.

Lipton, Ronald

2013-04-01

79

Geophysics guides particles physics

NASA Astrophysics Data System (ADS)

When geophysicists from the Air Force Geophysics Laboratory (AFGL), Hanscom Air Force Base, Mass., presented evidence of a sixth fundamental force at the AGU Fall Meeting in San Francisco last month, an uncommon thing happened. Particle physicists responded, in t h e press and elsewhere, to a potential scientific breakthrough made by a group of earth scientists.The event is uncommon because theoretical physicists have been leading the game of leapfrog between the theoreticians, who use mathematics to present new hypotheses and provide rigor for observations, and the experimentalists, who use measurements to test old theories or demonstrate the need for new ones. In recent years, particle physicists have published dozens of theories to explain the behavior of matter and energy on a subatomic scale, according to Purdue physicist Ephraim Fischbach. Some theories, with names like “supersymmetry” or “supergravity,” predict the existence of fundamental forces in addition to the four now known to exist: electromagnetism, gravity, and the strong and weak nuclear forces

Maggs, William Ward

80

Quantum Computing with Trapped Charged Particles

The concept of quantum computing has no clear cut origin. It emerged from combinations of information theory and quantum mechanical\\u000a concepts. A decisive step was taken by Feynman [414, 415] who considered the possibility of universal simulation, a quantum system which could simulate the physical behavior of any other. Feynman gave arguments which suggested that quantum evolution could be used

Günther Werth; Viorica N. Gheorghe; Fouad G. Major

81

Topics in Particle Physics Phenomenology

NASA Astrophysics Data System (ADS)

This thesis consists of topics in quantum field theory. In part A: (Chapter 1) A short review of heavy -quark physics, (Chapter 2) Spin-dependent forces in heavy -quark systems, (Chapter 3) Bound state effects in the (UPSILON) (--->) (gamma)+ resonance, and in part B, The compatibility of free fractional charge and Dirac magnetic monopoles. In Chapter 2, using the results of the fourth -order quark-antiquark interactions in perturbative QCD, we show that the spin-dependent potentials in the formalism of Eichten and Feinberg and Gromes have to be generalized to include the quark mass dependence. The recently observed hyperfine and fine structure splittings in the J/(psi) and (UPSILON) systems are found to agree with the purely perturbative QCD results for the scale parameter (LAMDA)(,MS) = 0.30 (+OR-) 0.06 GeV. With this value for (LAMDA)(,MS) we give some predictions on the T and toponium spectroscopies. In Chapter 3 we study the effect of b(')b bound state dynamics on the reaction (UPSILON) (--->) (gamma)+ resonance. We argue from our results that the recently discovered (zeta)(8320) must have a scalar, rather that a pseudoscalar, coupling to the b quark. In Part B, the existence of a free fractionally charged particle together with a monopole that has magnetic charge g = 1/2 e poses an apparent conflict. This conflict may be resolved by enlarging the exact gauge symmetry. The resulting constraint on GUTs is discussed and illustrated with an SU(9) GUT. Under certain assumptions, SU(9) is the smallest group to satisfy the constraints.

Pantaleone, James Thomas

82

Paradigms in Physics: Quantum Activities

NSDL National Science Digital Library

This web page provides a list of learning activities for Quantum Mechanics classes. Each activity includes a description and learning goals, guides for instructors, handouts or worksheets, and reflections of instructors who have used the activity when available. Included are activities for Operators, Eigenstates, Probability Densities, Stern-Gerlach Simulations, SchrÃ¶dinger's Equation, and Time Evolution. This material is part of the Paradigms in Physics project at Oregon State University. This work promotes the use of active student learning in upper division physics courses. Both learning materials and learning strategies are provided to help both students and instructors.

2010-02-08

83

Quantum dynamics in ultracold atomic physics

NASA Astrophysics Data System (ADS)

We review recent developments in the theory of quantum dynamics in ultracold atomic physics, including exact techniques and methods based on phase-space mappings that are applicable when the complexity becomes exponentially large. Phase-space representations include the truncated Wigner, positive- P and general Gaussian operator representations which can treat both bosons and fermions. These phase-space methods include both traditional approaches using a phase-space of classical dimension, and more recent methods that use a non-classical phase-space of increased dimensionality. Examples used include quantum Einstein-Podolsky-Rosen (EPR) entanglement of a four-mode BEC, time-reversal tests of dephasing in single-mode traps, BEC quantum collisions with up to 106 modes and 105 interacting particles, quantum interferometry in a multi-mode trap with nonlinear absorption, and the theory of quantum entropy in phase-space. We also treat the approach of variational optimization of the sampling error, giving an elementary example of a nonlinear oscillator.

He, Qiong-Yi; Reid, Margaret D.; Opanchuk, Bogdan; Polkinghorne, Rodney; Rosales-Zárate, Laura E. C.; Drummond, Peter D.

2012-02-01

84

Open statistical issues in particle physics

Many statistical issues arise in the analysis of Particle Physics experiments. We give a brief introduction to Particle Physics, before describing the techniques used by Particle Physicists for dealing with statistical problems, and also some of the open statistical questions.

Louis Lyons

2008-01-01

85

Connections Between LSST Science and Particle Physics

NASA Astrophysics Data System (ADS)

We are in the midst of a revolution in physics. Observing the cosmos has provided compelling evidence for physics beyond the Standard Model of particle physics: non-zero neutrino masses, non-baryonic dark matter, dark energy and primordial inflation. Together with ordinary matter these constituents determine the structure of the Universe. The necessary, but puzzling, connection between the inner space of quantum reality and outer space of cosmic reality will enable the discovery of new particle physics through astrophysical observations and may reconcile quantum mechanics and general relativity in a new synthesis: a Standard Model of the Universe. LSST will significantly contribute to answering the following questions: What is dark energy? What is dark matter? What are the neutrino masses? Was primordial inflation responsible for the origin of large-scale structure (LSS)? Did it leave observable imprints that can shed light on the unification of the fundamental forces? Can gravity be described in a unified quantum framework with the other forces? Precision cosmological observations will enable falsification of models covering the inflationary epoch, through the “dark ages”, to the first generation of stars and galaxies, and the current cosmic acceleration. LSST will study the impact of dark energy on both the history of cosmic expansion and growth of LSS using diverse techniques based on: weak-lensing, baryon acoustic oscillations, supernovae, galaxy cluster counts and strong lensing of quasars. Inconsistencies in the results may signal deficiencies in General Relativity and the need for a new theory of gravity. Properties of dark matter will be gleaned by studying the evolution of structure and by strong-lensing of galaxies, quasars and supernovae. Precision measurements of the matter power spectra vs cosmic time will constrain the sum of neutrino masses. LSST will probe inflation using cosmic shear and the spatial power spectrum of galaxies.

Tyson, J. A.; Burchat, P.; Dubois-Felsmann, G. P.; Kahn, S. M.; Shipsey, I.; Thaler, J.

2013-01-01

86

Quantum statistics of charged particle systems

This book presents information on the following topics: basic concepts for Coulomb systems; quantum statistics of many-particle systems; the method of Green's functions in quantum statistics; the binary collision approximation; application of the Green's function technique to Coulomb systems; many-particle complexes and T-matrices; cluster formation and the chemical picture; single particle excitations; equilibrium properties in classical and quasiclassical approximation; the

W. D. Kraeft; W. Ebeling; D. Kremp; G. Ropke

1986-01-01

87

Quantum Gravity of IED Particles

NASA Astrophysics Data System (ADS)

The internally electrodynamic (IED) model, developed based on overall experimental observations since 2000, briefly states that a simple material particle like electron is composed of an oscillatory charge of a characteristic frequency ? and zero rest mass, generally also traveling at velocity v, and the resulting Doppler-effected electromagnetic waves (E,B)'s. Based on first principles solutions for the IED processes a range of basic particle equations/properties have become predictable. One prediction is: two IED particles of masses M,M2 (=?i/c, i=1,2) and charges q1,q2 separated at r apart in a dielectric vacuum act always on one another an attractive force F=?F12F21=C M1M24??0r^2, where Fi j=qjvpjxBi is the Lorentz or depolarization radiation force on qj due to the radiation depolarization field Epi=-?0^*Ei of qi, electric field Ei, and magnetic field Bi, with Epi driving qj into motion at velocity vpj= qjd EpiMj), i,j=1,2; C = ??0^*e^4 ?0^2 h^2?l with q1,q2=±e and e, ?0, h fundamental constants of the usual meaning. F resembles directly Newton's gravitational force. The fields Ei,Bi are by nature quantized at the scale of Planck constant h; consequently Epi and therefore F are each quantized at the scale h. The present work gives a formal quantum electrodynamic re-derivation of this force. See e.g. a) arxiv:0812.3951, b) J Phys Conf Ser128. 012019, 2008.

Zheng-Johansson, J.

2009-05-01

88

NASA Astrophysics Data System (ADS)

Particle Physics, Second Edition is a concise and lucid account of the fundamental constituents of matter. The standard model of particle physics is developed carefully and systematically, without heavy mathematical formalism, to make this stimulating subject accessible to undergraduate students. Throughout, the emphasis is on the interpretation of experimental data in terms of the basic properties of quarks and leptons, and extensive use is made of symmetry principles and Feynman diagrams, which are introduced early in the book. The Second Edition brings the book fully up to date, including the discovery of the top quark and the search for the Higgs boson. A final short chapter is devoted to the continuing search for new physics beyond the standard model. Particle Physics, Second Edition features: * A carefully structured and written text to help students understand this exciting and demanding subject. * Many worked examples and problems to aid student learning. Hints for solving the problems are given in an Appendix. * Optional "starred" sections and appendices, containing more specialised and advanced material for the more ambitious reader.

Martin, B. R.; Shaw, G.

1998-01-01

89

Quantum flutter of supersonic particles in one-dimensional quantum liquids

NASA Astrophysics Data System (ADS)

Fast obstacles in a medium are responsible for striking physical phenomena, such as aerodynamic flutter, ?erenkov radiation and acoustic shock waves. In a hydrodynamic picture, quantum systems exhibit analogues of these dynamical features. Here we uncover novel quantum dynamics induced by fast particles by considering impurities injected supersonically into a one-dimensional quantum liquid. We find that the injected particle never comes to a full stop, at odds with conventional expectations of relaxation. Furthermore the system excites a new type of collective mode, manifesting itself in several observable quantities, such as long-lived oscillations in the velocity of the injected particle and simultaneous oscillations of the correlation hole formed around the impurity. These features are inherently quantum-mechanical and provide an example of a dynamically formed quantum coherent state propagating through a many-body environment while maintaining its coherence. The signatures of these effects can be probed directly with existing experimental tools.

Mathy, Charles J. M.; Zvonarev, Mikhail B.; Demler, Eugene

2012-12-01

90

Relativistic quantum mechanics of supersymmetric particles

NASA Astrophysics Data System (ADS)

The quantum mechanics of an electron in an external field is developed by Hamiltonian path integral methods. The electron is described classically by an action which is invariant under gauge supersymmetry transformations as well as worldline reparametrizations. The simpler case of a spinless particle is first reviewed and it is pointed out that a strictly canonical approach does not exist. This follows formally from the gauge invariance properties of the action and physically it corresponds to the fact that particles can travel backwards as well as forward in coordinate time. However, appropriate application of path integral techniques yields directly the proper time representation of the Feynman propagator. Next we extend the formalism to systems described by anticommuting variables. This problem presents some difficulty when the dimension of the phase space is odd, because the holomorphic representation does not exist. It is shown, however, that the usual connection between the evolution operator and the path integral still holds provided one indludes in the action the boundary term that makes the classical variational principle well defined. The path integral for the relativistic spinning particle is then evaluated and it is shown to lead directly to a representation for the Feynman propagator in terms of two proper times, one commuting, the other anticommuting, which appear in a symmetric manner. This representation is used to derive scattering amplitudes in an external field. In this step the anticommuting proper time is integrated away and the analysis is carried in terms of one (commuting) proper time only, just as in the spinless case. Finally, some properties of the quantum mechanics of the ghost particles that appear in the path integral for constrained systems are developed in an appendix.

Henneaux, Marc; Teitelboim, Claudio

1982-10-01

91

Relativistic quantum mechanics of supersymmetric particles

The quantum mechanics of an electron in an external field is developed by Hamiltonian path integral methods. The electron is described classically by an action which is invariant under gauge sypersymmetry transformations as well as worldline reparametrizations. The simpler case of a spinless particle is first reviewed and it is pointed out that a strictly canonical approach does not exist. This follows formally from the gauge invariance properties of the action and physically it corresponds to the fact that particles can travel backwards as well as forward in coordinate time. However, appropriate application of path integral techniques yields directly the proper time representation of the Feynman propagator. Next we extend the formalism to systems described by anticommuting variables. This problem presents some difficulty when the dimension of the phase space is odd, because the holomorphic representation does not exist. It is shown, however, that the usual connection between the evolution operator and the path integral still holds provided one includes in the action the bounary term that makes the classical variational principle well defined. The path integral for the relativistic spinning particle is then evaluated and it is shown to lead directly to a representation for the Feynman propagator in terms of two proper times, one commuting, the other anticommuting, which appear in a symmetric manner. This representation is used to derive scattering amplitudes in an external field. In this step the anticommuting proper time is integrated away and the analysis is carried in terms of one (commuting) proper time only, just as in the spinless case. Finally, some properties of the quantum mechanics of the ghost particles that appear in the path integral for constrained systems are developed in an appendix.

Henneaux, M.; Teitelboim, C.

1982-10-01

92

Research in particle physics. [Dept. of Physics, Boston Univ

Research accomplishments and current activities of Boston University researchers in high energy physics are presented. Principal areas of activity include the following: detectors for studies of electron[endash]positron annihilation in colliding beams; advanced accelerator component design, including the superconducting beam inflector, electrostatic quadrupoles, and the electrostatic muon kicker''; the detector for the MACRO (Monopole, Astrophysics, and Cosmic Ray Observatory) experiment; neutrino astrophysics and the search for proton decay; theoretical particle physics (electroweak and flavor symmetry breaking, hadron collider phenomenology, cosmology and astrophysics, new field-theoretic models, nonperturbative investigations of quantum field theories, electroweak interactions); measurement of the anomalous magnetic moment of the muon; calorimetry for the GEM experiment; and muon detectors for the GEM experiment at the Superconducting Super Collider.

Not Available

1992-09-01

93

Particle swarm optimization with particles having quantum behavior

In this paper, inspired by the analysis of convergence of PSO, we study the individual particle of a PSO system moving in a quantum multidimensional space and establish a quantum delta potential well model for PSO. After that, a trial method of parameter control and QDPSO is proposed. The experiment result shows much advantage of QDPSO to the traditional PSO.

Jun Sun; Bin Feng; Wenbo Xu

2004-01-01

94

Supersymmetric Quantum Mechanics of the Relativistic Particle.

National Technical Information Service (NTIS)

An alternative formulation for the superparticle in a scalar potential is presented. This method is based on a combination between the ground state wave function representation and supersymmetric quantum mechanics. For the free relativistic particle case,...

J. Gamboa J. Zanelli

1986-01-01

95

Quantum and classical dissipation of charged particles

A Hamiltonian approach is presented to study the two dimensional motion of damped electric charges in time dependent electromagnetic fields. The classical and the corresponding quantum mechanical problems are solved for particular cases using canonical transformations applied to Hamiltonians for a particle with variable mass. Green’s function is constructed and, from it, the motion of a Gaussian wave packet is studied in detail. -- Highlights: •Hamiltonian of a damped charged particle in time dependent electromagnetic fields. •Exact Green’s function of a charged particle in time dependent electromagnetic fields. •Time evolution of a Gaussian wave packet of a damped charged particle. •Classical and quantum dynamics of a damped electric charge.

Ibarra-Sierra, V.G. [Departamento de Física, Universidad Autónoma Metropolitana at Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 México D.F. (Mexico)] [Departamento de Física, Universidad Autónoma Metropolitana at Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 México D.F. (Mexico); Anzaldo-Meneses, A.; Cardoso, J.L.; Hernández-Saldaña, H. [Área de Física Teórica y Materia Condensada, Universidad Autónoma Metropolitana at Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, Azcapotzalco, 02200 México D.F. (Mexico)] [Área de Física Teórica y Materia Condensada, Universidad Autónoma Metropolitana at Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, Azcapotzalco, 02200 México D.F. (Mexico); Kunold, A., E-mail: akb@correo.azc.uam.mx [Área de Física Teórica y Materia Condensada, Universidad Autónoma Metropolitana at Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, Azcapotzalco, 02200 México D.F. (Mexico); Roa-Neri, J.A.E. [Área de Física Teórica y Materia Condensada, Universidad Autónoma Metropolitana at Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, Azcapotzalco, 02200 México D.F. (Mexico)] [Área de Física Teórica y Materia Condensada, Universidad Autónoma Metropolitana at Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, Azcapotzalco, 02200 México D.F. (Mexico)

2013-08-15

96

Final Report: Particle Physics Research Program

We describe recent progress in accelerator-based experiments in high-energy particle physics and progress in theoretical investigations in particle physics. We also describe future plans in these areas.

Karchin, Paul E.

2011-09-01

97

Quantum Security for the Physical Layer

The physical layer describes how communication signals are encoded and transmitted across a channel. Physical security often requires either restricting access to the channel or performing periodic manual inspections. In this tutorial, we describe how the field of quantum communication offers new techniques for securing the physical layer. We describe the use of quantum seals as a unique way to test the integrity and authenticity of a communication channel and to provide security for the physical layer. We present the theoretical and physical underpinnings of quantum seals including the quantum optical encoding used at the transmitter and the test for non-locality used at the receiver. We describe how the envisioned quantum physical sublayer senses tampering and how coordination with higher protocol layers allow quantum seals to influence secure routing or tailor data management methods. We conclude by discussing challenges in the development of quantum seals, the overlap with existing quantum key distribution cryptographic services, and the relevance of a quantum physical sublayer to the future of communication security.

Humble, Travis S [ORNL

2013-01-01

98

Quantum information and physics: some future directions

I consider some promising future directions for quantum information theory that could influence the development of 21st century physics. Advances in the theory of the distinguishability of superoperators may lead to new strategies for improving the precision of quantum-limited measurements. A better grasp of the properties of multi-partite quantum entanglement may lead to deeper understanding of strongly-coupled dynamics in quantum

John Preskill

2000-01-01

99

Quantum Physics and the Nature of Computation

\\u000a Quantum physics is a fascinating area from a computational viewpoint. The features that make quantum systems prohibitively\\u000a hard to simulate classically are precisely the aspects exploited by quantum computation to obtain exponential speedups over\\u000a classical computers. In this talk I will survey our current understanding of the power of quantum computers and prospects\\u000a for experimentally realizing them in the near

Umesh V. Vazirani

2005-01-01

100

The Physical Implementation of Quantum Computation

After a brief introduction to the principles and promise of quantum\\u000ainformation processing, the requirements for the physical implementation of\\u000aquantum computation are discussed. These five requirements, plus two relating\\u000ato the communication of quantum information, are extensively explored and\\u000arelated to the many schemes in atomic physics, quantum optics, nuclear and\\u000aelectron magnetic resonance spectroscopy, superconducting electronics, and\\u000aquantum-dot

David P. DiVincenzo

2000-01-01

101

Simulating physical phenomena with a quantum computer

NASA Astrophysics Data System (ADS)

In a keynote speech at MIT in 1981 Richard Feynman raised some provocative questions in connection to the exact simulation of physical systems using a special device named a ``quantum computer'' (QC). At the time it was known that deterministic simulations of quantum phenomena in classical computers required a number of resources that scaled exponentially with the number of degrees of freedom, and also that the probabilistic simulation of certain quantum problems were limited by the so-called sign or phase problem, a problem believed to be of exponential complexity. Such a QC was intended to mimick physical processes exactly the same as Nature. Certainly, remarks coming from such an influential figure generated widespread interest in these ideas, and today after 21 years there are still some open questions. What kind of physical phenomena can be simulated with a QC?, How?, and What are its limitations? Addressing and attempting to answer these questions is what this talk is about. Definitively, the goal of physics simulation using controllable quantum systems (``physics imitation'') is to exploit quantum laws to advantage, and thus accomplish efficient imitation. Fundamental is the connection between a quantum computational model and a physical system by transformations of operator algebras. This concept is a necessary one because in Quantum Mechanics each physical system is naturally associated with a language of operators and thus can be considered as a possible model of quantum computation. The remarkable result is that an arbitrary physical system is naturally simulatable by another physical system (or QC) whenever a ``dictionary'' between the two operator algebras exists. I will explain these concepts and address some of Feynman's concerns regarding the simulation of fermionic systems. Finally, I will illustrate the main ideas by imitating simple physical phenomena borrowed from condensed matter physics using quantum algorithms, and present experimental quantum simulations performed in a liquid NMR QC.

Ortiz, Gerardo

2003-03-01

102

Innovative quantum technologies for microgravity fundamental physics and biological research

NASA Technical Reports Server (NTRS)

This paper presents a new technology program, within the fundamental physics, focusing on four quantum technology areas: quantum atomics, quantum optics, space superconductivity and quantum sensor technology, and quantum field based sensor and modeling technology.

Kierk, I. K.

2002-01-01

103

Innovative quantum technologies for microgravity fundamental physics and biological research

NASA Technical Reports Server (NTRS)

This paper presents a new technology program, within the fundamental physics research program, focusing on four quantum technology areas: quantum atomics, quantum optics, space superconductivity and quantum sensor technology, and quantum fluid based sensor and modeling technology.

Kierk, I.; Israelsson, U.; Lee, M.

2001-01-01

104

Analysis of the two-particle controlled interacting quantum walks

NASA Astrophysics Data System (ADS)

We have recently proposed the two-particle controlled interacting quantum walks for building quantum Hash schemes (Li et al. Quantum Inf Proc, 2012. doi:10.1007/s11128-012-0421-8). In this paper, we adopt the mutual information, the measurement-induced disturbance and the quantum mutual information to measure the classical correlation, the quantum correlation and the total correlation between two particles respectively. Our conclusion is that the correlation between the particles of the two-particle controlled interacting quantum walks is similar to that of the two-particle interacting quantum walks. It is superb for keeping the quantum Hash scheme safe.

Li, Dan; Zhang, Jie; Ma, Xiu-Wen; Zhang, Wei-Wei; Wen, Qiao-Yan

2013-06-01

105

Physical State Space of Quantum Electrodynamics.

National Technical Information Service (NTIS)

Starting from the fact that electrically charged particles are massive we derive a criterion which characterizes the state space of quantum electrodynamics. This criterion clarifies the special role of the electric charge amongst the uncountably many supe...

D. Buchholz

1982-01-01

106

Physical and numerical viscosity for quantum hydrodynamics

Viscous stabilizations of the quantum hydrodynamic equations are studied. The quantum hydrodynamic model consists of the conservation laws for the particle density, momen-\\u000atum, and energy density, including quantum corrections from the Bohm potential. Two different stabilizations are analyzed. First, viscous terms are derived using a Fokker-Planck collision operator in the Wigner equation. The existence of solutions (with strictly positive

Ansgar Jüngel; Jospa Pina Miliši?

2007-01-01

107

Research in theoretical particle physics. Technical progress report, May 1, 1991--April 30, 1992

This report discusses the following topics in high energy physics: dynamical symmetry breaking and Schwinger-Dyson equation; consistency bound on the minimal model Higgs mass; tests of physics beyond the standard model; particle astrophysics; the interface between perturbative and non-perturbative QCD; cosmology; anisotropy in quantum networks and integer quantum hall behavior; anomalous color transparency; quantum treatment of solitons; color transparency; quantum stabilization of skyrmions; and casimir effect. (LSP)

McKay, D.W.; Munczek, H.; Ralston, J.

1992-05-01

108

The dialogue between particle physics and cosmology

In the last decade, a very close relationship has developed between particle physics and cosmology. The purpose of these lectures is to introduce particle physicists to the many scientific connections between the two fields. Before entering into the discussion of specific topics, it will first be shown that particle physics and cosmology are completely interdependent. 173 refs., 35 figs., 5 tabs.

Sadoulet, B.

1988-04-01

109

Particle Physics on the Eve of Lhc

NASA Astrophysics Data System (ADS)

Fundamentals of particle physics. The quantum number of color, colored quarks and dynamic models of Hadrons composed of quasifree quarks / V. Matveev, A. Tavkhelidze. Discovery of the color degree of freedom in particle physics: a personal perspective / O. W. Greenberg. The evolution of the concepts of energy, momentum, and mass from Newton and Lomonosov to Einstein and Feynman / L. Okun -- Physics at accelerators and studies in SM and beyond. Search for new physics at LHC (CMS) / N. Krasnikov. Measuring the Higgs Boson(s) at ATLAS / C. Kourkoumelis. Beyond the standard model physics reach of the ATLAS experiment / G. Unel. The status of the International Linear Collider / B. Foster. Review of results of the electron-proton collider HERA / V. Chekelian. Recent results from the Tevatron on CKM matrix elements from Bs oscillations and single top production, and studies of CP violation in Bs Decays / J. P. Fernández. Direct observation of the strange b Barion [symbol] / L. Vertogradov. Search for new physics in rare B Decays at LHCb / V. Egorychev. CKM angle measurements at LHCb / S. Barsuk. Collider searches for extra spatial dimensions and black holes / G. Landsberg -- Neutrino Physics. Results of the MiniBooNE neutrino oscillation experiment / Z. Djurcic. MINOS results and prospects / J. P. Ochoa-Ricoux. The new result of the neutrino magnetic moment measurement in the GEMMA experiment / A. G. Beda ... [et al.]. The Baikal neutrino experiment: status, selected physics results, and perspectives / V. Aynutdinov ... [et al.]. Neutrino telescopes in the deep sea / V. Flaminio. Double beta decay: present status / A. S. Barabash. Beta-beams / C. Volpe. T2K experiment / K. Sakashita. Non-standard neutrino physics probed by Tokai-to-Kamioka-Korea two-detector complex / N. Cipriano Ribeiro ... [et al.]. Sterile neutrinos: from cosmology to the LHC / F. Vannucci. From Cuoricino to Cuore towards the inverted hierarchy region / C. Nones. The MARE experiment: calorimetric approach to the direct measurement of the neutrino mass / E. Andreotti. Electron angular correlation in neutrinoless double beta decay and new physics / A. Ali, A. Borisov, D. Zhuridov. Neutrino energy quantization in rotating medium / A. Grigoriev, A. Studenikin. Neutrino propagation in dense magnetized matter / E. V. Arbuzova, A. E. Lobanov, E. M. Murchikova. Plasma induced neutrino spin flip via the neutrino magnetic moment / A. Kuznetsov, N. Mikheev -- Astroparticle physics and cosmology. International Russian-Italian mission "RIM-PAMELA" / A. M. Galper .. [et al.]. Dark Matter searches with AMS-02 experiment / A. Malinin. Investigating the dark halo / R. Bernabei ... [et al.]. Search for rare processes at Gran Sasso / P. Belli ... [et al.]. Anisotropy of Dark Matter annihilation and remnants of Dark Matter clumps in the galaxy / V. Berezinsky, V. Dokuchaev, Yu. Eroshenko. Current observational constraints on inflationary models / E. Mikheeva. Phase transitions in dense quark matter in a constant curvature gravitational field / D. Ebert, V. Ch. Zhukovsky, A. V. Tyukov. Construction of exact solutions in two-fields models / S. Yu. Vernov. Quantum systems bound by gravity / M. L. Fil'chenkov, S. V. Kopylov, Y. P. Laptev -- CP violation and rare decays. Some puzzles of rare B-Decays / A. B. Kaidalov. Measurements of CP violation in b decays and CKM parameters / J. Chauveau. Evidence for D[symbol] mixing at BaBar / M. V. Purohit. Search for direct CP violation in charged kaon decays from NA48/2 experiment / S. Balev. [symbol] scattering lengths from measurements of K[symbol] and K± -> [symbol] decays at NA48/2 / D. Madigozhin. Rare kaon and hyperon decays in NA48 experiment / N. Molokanova. THE K+ -> [symbol]+vv¯ experiment at CERN / Yu. Potrebenikov. Recent KLOE results / B. Di Micco.Decay constants and masses of heavy-light mesons in field correlator method / A. M. Badalian. Bilinear R-parity violation in rare meson decays / A. Ali, A. V. Borisov, M. V. Sidorova. Final state interaction in K -> 2[symbol] decay / E. Shabalin -- Hadron physi

Studenikin, Alexander I.

2009-01-01

110

Quantum Interpretations in Modern Physics Instruction

NSDL National Science Digital Library

Just as expert physicists vary in their personal stances on interpretation in quantum mechanics, instructors hold different views on teaching interpretations of quantum phenomena in introductory modern physics courses. There has been relatively little research in the physics education community on the variation in instructional approaches with respect to quantum interpretation, and how instructional choices impact student thinking. We compare two modern physics courses taught at the University of Colorado with similar learning environments, but where the instructors held different views on how to teach students about interpretations of quantum processes. We find significant differences in how students from these two courses responded to a survey on their beliefs about quantum mechanics; findings also suggest that instructors who choose to address student ontologies should do so across a range of topics.

Baily, Charles; Finkelstein, Noah D.

2010-01-19

111

Quantum cascade lasers in chemical physics

NASA Astrophysics Data System (ADS)

In the short space of 15 years since their first demonstration, quantum cascade lasers have become the most useful sources of tunable mid-infrared laser radiation. This Letter describes these developments in laser technology and the burgeoning applications of quantum cascade lasers to infrared spectroscopy. We foresee the potential application of quantum cascade lasers in other areas of chemical physics such as research on helium droplets, in population pumping, and in matrix isolation infrared photochemistry.

Curl, Robert F.; Capasso, Federico; Gmachl, Claire; Kosterev, Anatoliy A.; McManus, Barry; Lewicki, Rafa?; Pusharsky, Michael; Wysocki, Gerard; Tittel, Frank K.

2010-02-01

112

Semiclassical physics and quantum fluctuations

We investigate theories in which classical and quantum-mechanical degrees of freedom interact dynamically. In commonly used semiclassical theories, such as those used to study inflationary-universe models, quantum fluctuations do not affect the dynamics of the classical variables. We construct a new semiclassical theory in which the quantum and classical fluctuations do affect each other; the Wigner probability function turns out to be a special case. Relevance to calculations of perturbations from inflation are discussed.

Boucher, W.; Traschen, J.

1988-06-15

113

Research in elementary particle physics

This paper discusses: CDF analysis; CDF system support; SSC laboratory development; solenoidal detector collaboration program; meson spectroscopy; conformal field theory; wormholes in quantum gravity; neural networks. (FI)

Kirsch, L.E.; Schnitzer, H.J.; Abbott, L.F.; Bensinger, J.R.; Blocker, C.A.

1990-01-01

114

Experiment and the foundations of quantum physics

Instead of having to rely on gedanken (thought) experiments, it is possible to base this discussion of the foundations of quantum physics on actually performed experiments because of the enormous experimental progress in recent years. For reasons of space, the author discusses mainly experiments related to the Einstein-Podolsky-Rosen paradox and Bell's theorem, that is, to quantum entanglement. Not only have

Anton Zeilinger

1999-01-01

115

Relativistic nuclear physics and quantum chromodynamics. Abstracts.

National Technical Information Service (NTIS)

The data of investigations on problems of high energy physics are given. Special attention pays to quantum chromodynamics at large distances, cumulative processes, multiquark states and relativistic nuclear collisions. (Atomindex citation 26:048467)

1994-01-01

116

Statistical problems in quantum physics

In this paper, we give a general and unified mathematical treatment for a number of statistical problems concerning optimal quantum measurements. It has at least one field of application, namely, the theory of quantum communication channels and optimal receivers of optical signals [I] . Of course, if we are concerned with the data already obtained by a given measurement, then

A. S. Holevo

117

Quantum Computation for Physical Modeling.

National Technical Information Service (NTIS)

One of the most famous American physicists of the twentieth century, Richard Feynman, in 1982 was the first to propose using a quantum mechanical computing device to efficiently simulate quantum mechanical many-body dynamics 1, 2, 3, a task that is expone...

J. Yepez

2002-01-01

118

Elementary particle physics---Experimental

We are continuing a research program in high energy experimental particle physics and particle astrophysics. Studies of high energy hadronic interactions were performed using several techniques, in addition, a high energy leptoproduction experiment was continued at the Fermi National Accelerator Laboratory. We are participants in a joint US/Japan program to study nuclear interactions at energies two orders of magnitude greater than those of existing accelerators. The data are being collected with ballon-borne emulsion chambers. The properties of nuclear interactions at these high energies will reveal whether new production mechanisms come into play due to the high nuclear densities and temperatures obtained. We carried out closely related studies of hadronic interactions in emulsions exposed to high energy accelerator beams. We are members of a large international collaboration which has exposed emulsion chamber detectors to beams of {sup 32}S and {sup 16}O with energy 60 and 200 GeV/n at CERN and 15 GeV/n at Brookhaven National Laboratory. The primary objectives of this program are to determine the existence and properties of the hypothesized quark-gluon phase of matter, and its possible relation to a variety of anomalous observations. Studies of leptoproduction processes at high energies involve two separate experiments, one using the Tevatron 500 GeV muon beam and the other exploring the >TeV regime. We are participants in Fermilab experiment E665 employing a comprehensive counter/streamer chamber detector system. During the past year we joined the DUMAND Collaboration, and have been assigned responsibility for development and construction of critical components for the deep undersea neutrino detector facility, to be deployed in 1991. In addition, we are making significant contributions to the design of the triggering system to be used.

Lord, J.J.; Burnett, T.H.; Wilkes, R.J.

1990-09-20

119

Studies in theoretical particle physics

This proposal focuses on research on three distinct areas of particle physics: (1) Nonperturbative QCD. I tend to continue work on analytic modelling of nonperturbative effects in the strong interactions. I have been investigating the theoretical connection between the nonrelativistic quark model and QCD. The primary motivation has been to understand the experimental observation of nonzero matrix elements involving current strange quarks in ordinary matter -- which in the quark model has no strange quark component. This has led to my present work on understanding constituent (quark model) quarks as collective excitations of QCD degrees of freedom. (2) Weak Scale Baryogenesis. A continuation of work on baryogenesis in the early universe from weak interactions. In particular, an investigation of baryogenesis occurring during the weak phase transition through anomalous baryon violating processes in the standard model of weak interactions. (3) Flavor and Compositeness. Further investigation of a new mechanism that I recently discovered for dynamical mass generation for fermions, which naturally leads to a family hierarchy structure. A discussion of recent past work is found in the next section, followed by an outline of the proposed research. A recent publication from each of these three areas is attached to this proposal.

Kaplan, D.B.

1991-07-01

120

Quantum Electrodynamics of Charged Particles without Spin

Feynman's formulation of quantum electrodynamics is shown to be equivalent to the Schwinger-Tomonaga theory also for spinless charged particles (mesons) as developed by Kanesawa and Tomonaga. The divergencies of the scattering matrix are analyzed to all orders in the fine-structure constant and it is found that mass and charge renormalizations do not remove all divergencies, unlike the electron case. The

F. Rohrlich

1950-01-01

121

Relativistic quantum mechanics of supersymmetric particles

The quantum mechanics of an electron in an external field is developed by Hamiltonian path integral methods. The electron is described classically by an action which is invariant under gauge sypersymmetry transformations as well as worldline reparametrizations. The simpler case of a spinless particle is first reviewed and it is pointed out that a strictly canonical approach does not exist.

Marc Henneaux; Claudio Teitelboim

1982-01-01

122

Quantum Algorithms: Applicable Algebra and Quantum Physics

Classical computer science relies on the concept of Turing machines as a unifying model of universal computation. According\\u000a to the modern Church-Turing Thesis, this concept is interpreted in the form that every physically reasonable model of computation\\u000a can be efficiently simulated on a probabilistic Turing machine. Recently this understanding, which was taken for granted for a long time, has\\u000a required

Thomas Beth; Martin Roetteler

2001-01-01

123

Topics in elementary particle physics

NASA Astrophysics Data System (ADS)

The author of this thesis discusses two topics in elementary particle physics:

Jin, Xiang

124

Particle Physics: From School to University.

ERIC Educational Resources Information Center

Discusses the teaching of particle physics as part of the A-level physics course in British secondary schools. Utilizes the quark model of hadrons and the conceptual kinematics of particle collisions, as examples, to demonstrate practical instructional possibilities in relation to student expectations. (JJK)

Barlow, Roger

1992-01-01

125

Quarked!--Adventures in Particle Physics Education

ERIC Educational Resources Information Center

Particle physics is a subject that can send shivers down the spines of students and educators alike--with visions of long mathematical equations and inscrutable ideas. This perception, along with a full curriculum, often leaves this topic the road less traveled until the latter years of school. Particle physics, including quarks, is typically not…

MacDonald, Teresa; Bean, Alice

2009-01-01

126

NASA Astrophysics Data System (ADS)

The authors describe the way in which quantum physics is introduced in the new AS (Advanced Subsidiary) course Advancing Physics. It is based on the sum over many paths approach developed by Richard Feynman and described at an appropriate level in his book, from which the following quotation is drawn.

Dobson, Ken; Lawrence, Ian; Britton, Philip

2000-11-01

127

Solution for quantum mechanical problem in physics

NASA Astrophysics Data System (ADS)

The Schrödinger equation is the fundamental equation of physics for describing quantum mechanical behavior. In this Paper the solution is obtained by Variational Homotopy perturbation method which is coupling of Variational iteration method and Homotopy Perturbation Method. The solution describes how the wave function of a physical system evolves over time.

Daga, Amruta; Pradhan, V. H.

2013-06-01

128

Quantum simulations of relativistic quantum physics in circuit QED

NASA Astrophysics Data System (ADS)

We present a scheme for simulating relativistic quantum physics in circuit quantum electrodynamics. By using three classical microwave drives, we show that a superconducting qubit strongly coupled to a resonator field mode can be used to simulate the dynamics of the Dirac equation and Klein paradox in all regimes. Using the same setup we also propose the implementation of the Foldy-Wouthuysen canonical transformation, after which the time derivative of the position operator becomes a constant of the motion.

Pedernales, J. S.; Di Candia, R.; Ballester, D.; Solano, E.

2013-05-01

129

International Particle Physics Masterclasses with LHC data

NASA Astrophysics Data System (ADS)

The International Particle Physics Masterclasses is an educational activity developed by the International Particle Physics Outreach Group with the aim to bring the excitement of cutting-edge particle-physics research into the classroom. Since 2005, every year, thousands of pupils in many countries all over the world become "scientists for a day" in research centres or universities close to their schools as they are introduced to the mysteries of particle physics. In 2012, 10 000 students from 148 institutions in 31 countries took part in this popular event over a month period. The program of a typical day includes lectures that give insight to topics and methods of fundamental research followed by a "hands-on" session where students perform measurements on real data from particle-physics experiments themselves. The last two years LHC data from the ALICE, ATLAS and CMS experiments were used. A overview of the performed measurements and the employed methodology is presented.

Foka, Panagiota

2014-04-01

130

CERN and the future of particle physics

NASA Astrophysics Data System (ADS)

With the start-up of the Large Hadron Collider, particle physics is entering into an exciting period of research and discovery with high prospects for exciting advances in our understanding of Nature. The results from the initial running at the LHC will provide the directions for the future of particle physics and as host to the LHC, CERN is in a unique position to play a key role in the future course of particle physics. Future major facilities in particle physics require the formation of collaborations on a global scale, and to this end organisational structures are being put in place to oversee such extended endeavours. This paper reviews the characteristic features of particle physics and analyses the routes to be taken for the future advancement of the field.

Heuer, Rolf-Dieter

2009-06-01

131

Quantum Physics Online: Quantum superposition in two dimensions

NSDL National Science Digital Library

This is a set of interactive Java applets illustrating two-dimensional quantum states. Eigenstates are shown for both the 2D square well and the 2D harmonic oscillators. Simulations are used to illustrate the time dependence of wavepackets moving in these two potentials as well. These applets are part of an extensive collection of animations and simulations illustrating a large range of quantum topics, and an ongoing effort for developing a fully interactive quantum-physics class. Both French and English versions are available.

Joffre, Manuel

2004-03-28

132

Quantum Physics Online: Quantum superposition in one dimension

NSDL National Science Digital Library

This is a set of interactive Java applets illustrating time dependence and superposition in one-dimensional quantum states. Simulations are used to illustrate the time dependence (real and imaginary parts) of eigenstates states, and superposition of eigenstates. There is an application of these ideas to a two-level model of an ammonia molecule. There is also an illustration of a harmonic oscillator with multiple states occupied, and coherent states. These applets are part of an extensive collection of animations and simulations illustrating a large range of quantum topics, and an ongoing effort for developing a fully interactive quantum-physics class. Both French and English versions are available.

Joffre, Manuel

2004-03-28

133

Development of quantum perspectives in modern physics

NSDL National Science Digital Library

Summary: Variations in student epistemic and ontological commitments can be characterized, and many students have preferences for realist interpretations of quantum phenomena. Abstract: Introductory undergraduate courses in classical physics stress a perspective that can be characterized as realist; from this perspective, all physical properties of a classical system can be simultaneously specified and thus determined at all future times. Such a perspective can be problematic for introductory quantum physics students, who must develop new perspectives in order to properly interpret what it means to have knowledge of quantum systems. We document this evolution in student thinking in part through pre- and post-instruction evaluations using the Colorado Learning Attitudes about Science Survey. We further characterize variations in student epistemic and ontological commitments by examining responses to two essay questions, coupled with responses to supplemental quantum attitude statements. We find that, after instruction in modern physics, many students are still exhibiting a realist perspective in contexts where a quantum-mechanical perspective is needed. We further find that this effect can be significantly influenced by instruction, where we observe variations for courses with differing learning goals. We also note that students generally do not employ either a realist or a quantum perspective in a consistent manner.

Baily, Charles; Finkelstein, Noah D.

2012-01-20

134

Quantum energy teleportation between spin particles in a Gibbs state

NASA Astrophysics Data System (ADS)

Energy in a multipartite quantum system appears from an operational perspective to be distributed to some extent non-locally because of correlations extant among the system's components. This non-locality allows users to transfer, in effect, locally accessible energy between sites of different system components by local operations and classical communication (LOCC). Quantum energy teleportation is a three-step LOCC protocol, accomplished without an external energy carrier, for effectively transferring energy between two physically separated, but correlated, sites. We apply this LOCC teleportation protocol to a model Heisenberg spin particle pair initially in a quantum thermal Gibbs state, making temperature an explicit parameter. We find in this setting that energy teleportation is possible at any temperature, even at temperatures above the threshold where the particles' entanglement vanishes. This shows for Gibbs spin states that entanglement is not fundamentally necessary for energy teleportation; correlation other than entanglement can suffice. Dissonance—quantum correlation in separable states—is in this regard shown to be a quantum resource for energy teleportation, more dissonance being consistently associated with greater energy yield. We compare energy teleportation from particle A to B in Gibbs states with direct local energy extraction by a general quantum operation on B and find a temperature threshold below which energy extraction by a local operation is impossible. This threshold delineates essentially two regimes: a high temperature regime where entanglement vanishes and the teleportation generated by other quantum correlations yields only vanishingly little energy relative to local extraction and a second low-temperature teleportation regime where energy is available at B only by teleportation.

Frey, Michael R.; Gerlach, Karl; Hotta, Masahiro

2013-11-01

135

Quantum Random Walks with General Particle States

NASA Astrophysics Data System (ADS)

A convergence theorem is obtained for quantum random walks with particles in an arbitrary normal state. This unifies and extends previous work on repeated-interactions models, including that of Attal and Pautrat (Ann Henri Poincaré 7:59-104 2006) and Belton (J Lond Math Soc 81:412-434, 2010; Commun Math Phys 300:317-329, 2010). When the random-walk generator acts by ampliation and either multiplication or conjugation by a unitary operator, it is shown that the quantum stochastic cocycle which arises in the limit is driven by a unitary process.

Belton, Alexander C. R.

2014-06-01

136

The Physical Renormalization of Quantum Field Theories

The profound revolutions in particle physics likely to emerge from current and future experiments motivates an improved understanding of the precise predictions of the Standard Model and new physics models. Higher order predictions in quantum field theories inevitably requires the renormalization procedure, which makes sensible predictions out of the naively divergent results of perturbation theory. Thus, a robust understanding of renormalization is crucial for identifying and interpreting the possible discovery of new physics. The results of this thesis represent a broad set of investigations in to the nature of renormalization. The author begins by motivating a more physical approach to renormalization based on gauge-invariant Green's functions. The resulting effective charges are first applied to gauge coupling unification. This approach provides an elegant formalism for understanding all threshold corrections, and the gauge couplings unify in a more physical manner compared to the usual methods. Next, the gauge-invariant three-gluon vertex is studied in detail, revealing an interesting and rich structure. The effective coupling for the three-gluon vertex, {alpha}(k{sub 1}{sup 2}, k{sub 2}{sup 2}, k{sub 3}{sup 2}), depends on three momentum scales and gives rise to an effective scale Q{sub eff}{sup 2}(k{sub 1}{sup 2}, k{sub 2}{sup 2}, k{sub 3}{sup 2}) which governs the (sometimes surprising) behavior of the vertex. The effects of nonzero internal masses are important and have a complicated threshold and pseudo-threshold structure. The pinch-technique effective charge is also calculated to two-loops and several applications are discussed. The Higgs boson mass in Split Supersymmetry is calculated to two-loops, including all one-loop threshold effects, leading to a downward shift in the Higgs mass of a few GeV. Finally, the author discusses some ideas regarding the overall structure of perturbation theory. This thesis lays the foundation for a comprehensive multi-scale analytic renormalization scheme based on gauge-invariant Green's functions, in which the scale ambiguity problem is reduced since physical kinematic invariants determine the arguments of the couplings.

Binger, Michael William.; /Stanford U., Phys. Dept. /SLAC

2007-02-20

137

Compact Stars: Nuclear Physics, Particle Physics and General Relativity

NSDL National Science Digital Library

This is a graduate level textbook which explores the areas of astrophysics and cosmology where nuclear physics, particle physics and general relativity combine. Included is material on the application of these divisions of physics in white dwarfs, neutron stars, and black holes while providing background information on stellar formation, pulsars and the strange-matter hypothesis.

Glendenning, Norman

2009-06-12

138

Trace Functions with Applications in Quantum Physics

NASA Astrophysics Data System (ADS)

We consider both known and not previously studied trace functions with applications in quantum physics. By using perspectives we obtain convexity statements for different notions of residual entropy, including the entropy gain of a quantum channel studied by Holevo and others. We give new proofs of Carlen-Lieb's concavity/convexity theorems for certain trace functions, by making use of the theory of operator monotone functions. We then apply these methods in a study of new classes of trace functions.

Hansen, Frank

2014-02-01

139

Discrete spacetime and relativistic quantum particles

NASA Astrophysics Data System (ADS)

We study a single quantum particle in discrete spacetime evolving in a causal way. We see that in the continuum limit, any massless particle with a two-dimensional internal degree of freedom obeys the Weyl equation, provided that we perform a simple relabeling of the coordinate axes or demand rotational symmetry in the continuum limit. It is surprising that this occurs regardless of the specific details of the evolution: it would be natural to assume that discrete evolutions giving rise to relativistic dynamics in the continuum limit would be very special cases. We also see that the same is not true for particles with larger internal degrees of freedom, by looking at an example with a three-dimensional internal degree of freedom that is not relativistic in the continuum limit. In the process, we give a formula for the Hamiltonian arising from the continuum limit of massless and massive particles in discrete spacetime.

Farrelly, Terence C.; Short, Anthony J.

2014-06-01

140

Particles and nuclei as quantum slings

NASA Astrophysics Data System (ADS)

Rotation of such objects as an atomic nucleus or a chromodynamical string can result in specific effects in scattering processes and multiparticle production. Secondary fragments of the rotating nucleus or of the decaying string can move like stones thrown from a sling. That would be detected as the azimuthal asymmetry of particle distributions in individual events. Non-classical states of the created particles like the Schr"\\{o}dinger cats are produced. Some classical and quantum-mechanical estimates of possible effects are given. Experimental facts which can be used for their verification are discussed.

Dremin, I. M.; Man'ko, V. I.

1998-05-01

141

Being qua becoming: Aristotle's "Metaphysics", quantum physics, and Process Philosophy

NASA Astrophysics Data System (ADS)

In Aristotle's First Philosophy, science and philosophy were partners, but with the rise of empiricism, went their separate ways. Metaphysics combined the rational and irrational (i.e. final cause/unmoved mover) elements of existence to equate being with substance, postulating prime matter as pure potential that was actuated by form to create everything. Modern science reveres pure reason and postulates its theory of being by a rigorous scientific methodology. The Standard Model defines matter as energy formed into fundamental particles via forces contained in fields. Science has proved Aristotle's universe wrong in many ways, but as physics delves deeper into the quantum world, empiricism is reaching its limits concerning fundamental questions of existence. To achieve its avowed mission of explaining existence completely, physics must reunite with philosophy in a metascience modeled on the First Philosophy of Aristotle. One theory of being that integrates quantum physics and metaphysics is Process Philosophy.

Johnson, David Kelley

142

Perspectives in Quantum Physics: Epistemological, Ontological and Pedagogical

NSDL National Science Digital Library

A common learning goal for modern physics instructors is for students to recognize a difference between the experimental uncertainty of classical physics and the fundamental uncertainty of quantum mechanics. Our studies suggest this notoriously difficult task may be frustrated by the intuitively realist perspectives of introductory students, and a lack of ontological flexibility in their conceptions of light and matter. We have developed a framework for understanding and characterizing student perspectives on the physical interpretation of quantum mechanics, and demonstrate the differential impact on student thinking of the myriad ways instructors approach interpretive themes in their introductory courses. Like expert physicists, students interpret quantum phenomena differently, and these interpretations are significantly influenced by their overall stances on questions central to the so-called measurement problem: Is the wave function physically real, or simply a mathematical tool? Is the collapse of the wave function an ad hoc rule, or a physical transition not described by any equation? Does an electron, being a form of matter, exist as a localized particle at all times? These questions, which are of personal and academic interest to our students, are largely only superficially addressed in our introductory courses, often for fear of opening a Pandoraâs Box of student questions, none of which have easy answers. We show how a transformed modern physics curriculum (recently implemented at the University of Colorado) may positively impact student perspectives on indeterminacy and wave-particle duality, by making questions of classical and quantum reality a central theme of our course, but also by making the beliefs of our students, and not just those of scientists, an explicit topic of discussion.

Baily, Charles

2012-01-20

143

Frontiers of particle beam physics

First, a review is given of various highly-developed techniques for particle handling which are, nevertheless, being vigorously advanced at the present time. These include soft superconductor radio frequency cavities, hard superconductor magnets, cooling rings for ions and anti-protons, and damping rings for electrons. Second, attention is focused upon novel devices for particle generation, acceleration, and focusing. These include relativistic klystrons and free electron laser power sources, binary power multipliers, photocathodes, switched-power linacs, plasma beat-wave accelerators, plasma wake-field accelerators, plasma lenses, plasma adiabatic focusers and plasma compensators. 12 refs.

Sessler, A.M.

1989-11-01

144

Beams for the Intensity Frontier of Particle Physics

NASA Astrophysics Data System (ADS)

Advances in high intensity beams have driven particle physics forward since the inception of the field. State-of-the-art and next generation high intensity beams will drive experiments searching for ultrarare processes sensitive through quantum corrections to new particle states far beyond the reach of direct production in foreseeable beam colliders. The recent discovery of the ultrarare B meson decay Bs ? ??, with a branching fraction of 3 × 10-9 for example, has set stringent limits on new physics within direct reach of the Large Hadron Collider. Today, even in the context of the Higgs boson discovery, observation of finite neutrino masses is the only laboratory evidence of physics beyond the Standard Model of particle physics. The tiny mass scale of neutrinos may foretell and one day expose physics that connects quarks and leptons together at the "grand unification" scale and may be the portal through which our world came to the matter-dominated state so different from conditions we expect in the early universe. Here we describe next generation neutrino and rare processes experiments that will deeply probe these and other questions central to the field of particle physics.

Tschirhart, Robert S.

2014-02-01

145

Finite quantum physics and noncommutative geometry

Conventional discrete approximations of a manifold do not preserve its\\u000anontrivial topological features. In this article we describe an approximation\\u000ascheme due to Sorkin which reproduces physically important aspects of manifold\\u000atopology with striking fidelity. The approximating topological spaces in this\\u000ascheme are partially ordered sets (posets). Now, in ordinary quantum physics on\\u000aa manifold $M$, continuous probability densities generate

A. P. Balachandran; G. Bimonte; E. Ercolessi; G. Landi; F. Lizzi; G. Sparano; P. Teotoniosobrinho

1995-01-01

146

The Standard Model of Particle Physics

NSDL National Science Digital Library

This site provides an introduction to the standard model of particle physics, the theory which is currently most widely accepted to describe what matter is made of. All of the elementary particles of matter and the fundamental forces are characterized and classified. The site also provides information about the testing of the standard model.

2007-12-10

147

Artificial Quantum Solids: Physics, Fabrication and Applications.

National Technical Information Service (NTIS)

This report describes research carried out at the University of Nebraska and at the University of Notre Dame in the physics and fabrication of self-assembled arrays of quantum dots and wires. Such arrays have shown enhanced optical non-linearities, novel ...

S. Bandyopadhyay A. E. Miller

1998-01-01

148

Quantum Inferential Leaps: The Rhetoric of Physics.

ERIC Educational Resources Information Center

Considers the epistemological implications of a changing understanding of reality, based on contemporary connections between rhetoric as epistemic (questioning underlying assumptions about modernist conceptualizations of science and language) and quantum physics (rejecting the notion of an objective reality existing independent of observers).…

McPhail, Mark Lawrence

1992-01-01

149

Elementary Particles and the Laws of Physics

Developing a theory that seamlessly combines relativity and quantum mechanics, the most important conceptual breakthroughs in twentieth century physics, has proved to be a difficult and ongoing challenge. This book details how two distinguished physicists and Nobel laureates have explored this theme in two lectures given in Cambridge, England, in 1986 to commemorate the famous British physicist Paul Dirac. Given

Richard P. Feynman; Steven Weinberg

1987-01-01

150

Elementary Particles and the Laws of Physics

Developing a theory that seamlessly combines relativity and quantum mechanics, the most important conceptual breakthroughs in twentieth century physics, has proved to be a difficult and ongoing challenge. This book details how two distinguished physicists and Nobel laureates have explored this theme in two lectures given in Cambridge, England, in 1986 to commemorate the famous British physicist Paul Dirac. Given

Richard P. Feynman; Steven Weinberg

1999-01-01

151

Theoretical particle physics. Progress report, FY 1993

This report discusses the following topics: Heavy Quark Physics; Chiral Perturbation Theory; Skyrmions; Large-N Limit; Weak Scale Baryogenesis; Supersymmetry; Rare Decays; Technicolor; Chiral Lattice Fermions; Pauli-Villars Regulator and the Higgs Mass Bound; Higgs and Yukawa Interactions; Gauge Fixing; and Quantum Beables.

Not Available

1993-09-30

152

Nuclear physics with strange particles

Recent progress in the understanding of strange particle interactions with nuclear systems is reviewed. We discuss the relative merits of various reactions such as (K/sup -/, ..pi../sup +-/), (..pi../sup +/, K/sup +/), or (..gamma.., K/sup +/) for hypernuclear production. The structure of /sub ..lambda..//sup 13/C is analyzed in some detail, in order to illustrate the role of the ..lambda..N residual interaction and approximate dynamical symmetries in hypernuclear structure. Recent results on the single particle states of a ..lambda.. in heavy systems, as revealed by (..pi../sup +/, K/sup +/) reaction studies, are used to extract information on the density dependence and effective mass which characterize the ..lambda..-nucleus mean field. Finally, we develop the idea the K/sup +/-nucleus scattering at low energies is sensitive to the subtle ''swelling'' effects for nucleons bound in nuclei. 64 refs., 13 figs.

Dover, C.B.

1988-01-01

153

The Concept of Particle Weights in Local Quantum Field Theory

NASA Astrophysics Data System (ADS)

The concept of particle weights has been introduced by Buchholz and the author in order to obtain a unified treatment of particles as well as (charged) infraparticles which do not permit a definition of mass and spin according to Wigner's theory. Particle weights arise as temporal limits of physical states in the vacuum sector and describe the asymptotic particle content. Following a thorough analysis of the underlying notion of localizing operators, we give a precise definition of this concept and investigate the characteristic properties. The decomposition of particle weights into pure components which are linked to irreducible representations of the quasi-local algebra has been a long-standing desideratum that only recently found its solution. We set out two approaches to this problem by way of disintegration theory, making use of a physically motivated assumption concerning the structure of phase space in quantum field theory. The significance of the pure particle weights ensuing from this disintegration is founded on the fact that they exhibit features of improper energy-momentum eigenstates, analogous to Dirac's conception, and permit a consistent definition of mass and spin even in an infraparticle situation.

Porrmann, Martin

2000-05-01

154

Nuclear and Particle Physics Simulations: The Consortium of Upper-Level Physics Software

NASA Astrophysics Data System (ADS)

The Consortium for Upper Level Physics Software (CUPS) has developed a comprehensive series of Nine Book/Software packages that Wiley will publish in FY `95 and `96. CUPS is an international group of 27 physicists, all with extensive backgrounds in the research, teaching, and development of instructional software. The project is being supported by the National Science Foundation (PHY-9014548), and it has received other support from the IBM Corp., Apple Computer Corp., and George Mason University. The Simulations being developed are: Astrophysics, Classical Mechanics, Electricity & Magnetism, Modern Physics, Nuclear and Particle Physics, Quantum Mechanics, Solid State, Thermal and Statistical, and Wave and Optics.

Bigelow, Roberta; Moloney, Michael J.; Philpott, John; Rothberg, Joseph

1995-06-01

155

Research on elementary particle physics

This report describes the activities of the University of Illinois Experimental High Energy Physics Group. The physicists in the University of Illinois High Energy Physics Group are engaged in a wide variety of experiments at current and future accelerator laboratories. These include: (1) The CDF experiment at the Fermilab Tevetron p{bar p} collider. (2) Design and developmental work for the SDC group at SSCL. (3) Experiments at the wide band photon beam at Fermilab. (4) The SLD experiment at SLAC and design studies for a {tau}-charm factor. (5) CP violation experiments at Fermilab. (6) The HiRes cosmic ray experiment at Dugway Proving Grounds, Utah. (7) Computational facilities. (8) Electronics systems development.

Holloway, L.E.; O'Halloran, T.A.

1992-05-01

156

Physics on the boundary between classical and quantum mechanics

NASA Astrophysics Data System (ADS)

Nature's laws in the domain where relativistic effects, gravitational effects and quantum effects are all comparatively strong are far from understood. This domain is called the Planck scale. Conceivably, a theory can be constructed where the quantum nature of phenomena at such scales can be attributed to something fundamentally simpler. However, arguments that quantum mechanics cannot be explained in terms of any classical theory using only classical logic seem to be based on sound mathematical considerations: there can't be physical laws that require "conspiracy". It may therefore be surprising that there are several explicit quantum systems where these considerations apparently do not apply. In the lecture we will show several such counterexamples. These are quantum models that do have a classical origin. The most curious of these models is superstring theory. This theory is often portrayed as to underly the quantum field theory of the subatomic particles, including the "Standard Model". So now the question is asked: how can this model feature "conspiracy", and how bad is that? Is there conspiracy in the vacuum fluctuations?

't Hooft, Gerard

2014-04-01

157

Theoretical particle physics, Task A

This report briefly discusses the following topics: The Spin Structure of the Nucleon; Solitons and Discrete Symmetries; Baryon Chiral Perturbation Theory; Constituent Quarks as Collective Excitations; Kaon Condensation; Limits on Neutrino Masses; The 17 KeV Neutrino and Majoron Models; The Strong CP Problem; Renormalization of the CP Violating {Theta} Parameter; Weak Scale Baryogenesis; Chiral Charge in Finite Temperature QED; The Heavy Higgs Mass Bound; The Heavy Top Quark Bound; The Heavy Top Quark Condensate; The Heavy Top Quark Vacuum Instability; Phase Diagram of the Lattice Higgs-Yukawa Model; Anomalies and the Standard Model on the Lattice; Constraint Effective Potential in a Finite Box; Resonance Picture in a Finite Box; Fractal Dimension of Critical Clusters; Goldstone Bosons at Finite Temperature; Cluster Algorithms and Scaling in CP(N) Models; Rare Decay Modes of the Z{degrees} Vector Boson; Parity-Odd Spin-Dependent Structure Functions; Radiative Corrections, Top Mass and LEP Data; Supersymmetric Model with the Higgs as a Lepton; Chiral Change Oscillation in the Schwinger Model; Electric Dipole Moment of the Neutron; DOE Grand Challenge Program; and Lattice Quantum Electrodynamics.

Not Available

1991-07-01

158

Elementary particle physics at the University of Florida

This report discusses research in the following areas: theoretical elementary particle physics; experimental elementary particle physics; axion project; SSC detector development; and computer acquisition. (LSP).

Not Available

1991-12-01

159

Effective Lagrangians in Elementary Particle Physics

Non-linear effective Lagrangians are constructed to represent the low energy phenomenology of elementary particles. As approximate descriptions of the dynamics of hadrons, these models simulate the expected {but unproven} behavior of more complex theories such as quantum Chromo-dynamics {QCD}. A general formalism for non-linear models was developed in the late 1960's by Coleman, Wess and Zumino. This dissertation utilizes and

Charles Garrett Trahern

1982-01-01

160

Hyperon particle physics at JHF

This paper discusses the possibility of a program in hyperon decay physics at the Japan Hadron Facility. The study of hyperon decays has a history of over 40 years of experimental results. However, many of the earliest results are still the best available and there are many gaps in the data. The static properties of hyperons (masses, magnetic moments) are in relatively good shape. Much work remains to be done on the decays of hyperons and hyperon resonances. There are current experiments at the major accelerator facilities that address various hyperon decays, but no comprehensive program. This presents an excellent opportunity for such a program to be considered at JHF. The high-intensity beams of {pi}, K, and p beams will allow experiments to be designed that optimize the properties of the hyperons being studied. It is possible to envision experiments with samples of 10{sup 9} hyperon decays in 10{sup 7} sec runs.

Mischke, R.E.

1998-12-01

161

Quantum correlations in two-particle Anderson localization.

We predict quantum correlations between noninteracting particles evolving simultaneously in a disordered medium. While the particle density follows the single-particle dynamics and exhibits Anderson localization, the two-particle correlation develops unique features that depend on the quantum statistics of the particles and their initial separation. On short time scales, the localization of one particle becomes dependent on whether or not the other particle is localized. On long time scales, the localized particles show oscillatory correlations within the localization length. These effects can be observed in Anderson localization of nonclassical light and ultracold atoms. PMID:21230976

Lahini, Yoav; Bromberg, Yaron; Christodoulides, Demetrios N; Silberberg, Yaron

2010-10-15

162

Particle physics with the LHC data

In this talk, I give reasons why we regard GUT as a part of the Standard Model of Elementary Particle Physics that explain all phenomena observed at high energy experiments and in the universe, with a few notable exceptions. It is based on my introduction-to-elementary-particle-physics lectures for the first year graduate students at Sokendai, Graduate University for Advanced Studies. No new observation is made, but I think that it is important for us to examine the LHC data from the GUT viewpoint together with our fresh students.

Hagiwara, Kaoru [KEK Theory Center and Sokendai, Tsukuba 305-0801 (Japan)

2012-07-27

163

The Coming Revolutions in Particle Physics

NASA Astrophysics Data System (ADS)

Wonderful opportunities await particle physics over the next decade, with new instruments and experiments poised to explore the frontiers of high energy, infinitesimal distances, and exquisite rarity. I will review the insights of the decade just past and show how they lead us to the brink of a new period of rapid and profound discovery. We expect answers to questions that speak to our understanding of the everyday world: why are there atoms? why chemistry? why stable structures? and even what makes life possible? We are probing the meaning of identity for the fundamental particles: what makes an electron an electron, a neutrino a neutrino, and a top quark a top quark? Important clues, including the remarkable neutrality of atoms, lead us to investigate the unity of the two main classes of matter, the quarks and leptons. Gravity and particle physics, long separate disciplines, are enjoying a stimulating reunion, and we are learning how to investigate—with experiments—new conceptions of spacetime. We look forward to the Large Hadron Collider at CERN to explore the a new and critical energy scale of one trillion electron volts. If we are inventive enough, we may be able to follow the LHC's rich menu with the physics opportunities offered by a linear electron-positron collider, a (muon storage ring) neutrino factory, and experiments that use natural sources. I expect a remarkable flowering of experimental particle physics, and of theoretical physics that engages with experiment.

Quigg, Chris

2006-12-01

164

Anderson Localization for a Multi-Particle Quantum Graph

NASA Astrophysics Data System (ADS)

We study a multi-particle quantum graph with random potential. Taking the approach of multiscale analysis, we prove exponential and strong dynamical localization of any order in the Hilbert-Schmidt norm near the spectral edge. Apart from the results on multi-particle systems, we also prove Lifshitz-type asymptotics for single-particle systems. This shows in particular that localization for single-particle quantum graphs holds under a weaker assumption on the random potential than previously known.

Sabri, Mostafa

2014-11-01

165

Quantum gravity and spin-1/2 particle effective dynamics

NASA Astrophysics Data System (ADS)

Quantum gravity phenomenology opens up the possibility of probing Planck scale physics. Thus, by exploiting the generic properties that a semiclassical state of the compound system fermions plus gravity should have, an effective dynamics of spin-1/2 particles is obtained within the framework of loop quantum gravity. Namely, at length scales much larger than Planck length lP˜10-33 cm and below the wavelength of the fermion, the spin-1/2 dynamics in flat spacetime includes Planck scale corrections. In particular we obtain modified dispersion relations in vacuo for fermions. These corrections yield a time of arrival delay of the spin-1/2 particles with respect to a light signal and, in the case of neutrinos, a novel flavor oscillation. To detect these effects the corresponding particles must be highly energetic and should travel long distances. Hence neutrino bursts accompanying gamma ray bursts or ultrahigh energy cosmic rays could be considered. Remarkably, future neutrino telescopes may be capable of testing such effects. This paper provides a detailed account of the calculations and elaborates on results previously reported in a Letter. These are further amended by introducing a real parameter ? aimed at encoding our lack of knowledge of scaling properties of the gravitational degrees of freedom.

Alfaro, Jorge; Morales-Técotl, Hugo A.; Urrutia, Luis F.

2002-12-01

166

Vortex Physics in the Quantum Hall Bilayer

NASA Astrophysics Data System (ADS)

There exists a strong analogy between the quantum Hall bilayer system at total filling factor ? = 1 and a thin film superfluid, in which the groundstate is described as a condensate of particle-hole pairs. The analogy draws support from experiments which display near dissipationless transport properties at low temperatures. However dissipation is always present at any accessible temperature, suggesting that in a proper description, unpaired vortex-like excitations must be present. The mechanism by which this happens remains poorly understood. A key difference between the quantum Hall bilayer and simpler thin-film superfluids is that the vortices, more properly called merons in the former context, are charged objects. We demonstrate that a model in which disorder induces merons in the groundstate, through coupling to this charge, can naturally explain many of the observed imperfect superfluid properties...

Fertig, H. A.; Murthy, Ganpathy

2013-06-01

167

Keynote Speech: Quantum Physics and the Nature of Computation

Quantum physics is a fascinating area from a computational viewpoint. The features that make quantum systems prohibitively hard to simulate classically are precisely the aspects exploited by quantum computation to obtain exponential speedups over classical computers. In this talk I will survey our current understanding of the power (and limits) of quantum computers, and prospects for experimentally realizing them in

Umesh V. Vazirani

2007-01-01

168

The flnal report: Quantum dots: from fundamental physics to applications

BACKGROUND The research performed during the fellowship focused on the physics of quantum dots. Quantum dots are nano-sized semiconductors which exhibit strong conflne- ment efiects. In complete contrast to traditional semi- conductors with an energy band structure, electrons and holes in quantum dots are completely conflned and form bound states, somewhat reminiscent of an atom. In inorganic semiconductor quantum dots,

Richard J. Warburton

169

Visions: The coming revolutions in particle physics

Wonderful opportunities await particle physics over the next decade, with the coming of the Large Hadron Collider to explore the 1-TeV scale (extending efforts at LEP and the Tevatron to unravel the nature of electroweak symmetry breaking) and many initiatives to develop the understanding of the problem of identity and the dimensionality of spacetime.

Chris Quigg

2002-04-11

170

Theoretical Studies in Elementary Particle Physics

This final report summarizes work at Penn State University from June 1, 1990 to April 30, 2012. The work was in theoretical elementary particle physics. Many new results in perturbative QCD, in string theory, and in related areas were obtained, with a substantial impact on the experimental program.

Collins, John C.; Roiban, Radu S

2013-04-01

171

Current Experiments in Particle Physics (September 1996)

This report contains summaries of current and recent experiments in Particle Physics. Included are experiments at BEPC (Beijing), BNL, CEBAF, CERN, CESR, DESY, FNAL, Frascati, ITEP (Moscow), JINR (Dubna), KEK, LAMPF, Novosibirsk, PNPI (St. Petersburg), PSI, Saclay, Serpukhov, SLAC, and TRIUMF, and also several proton decay and solar neutrino experiments. Excluded are experiments that finished taking data before 1991. Instructions are given for the World Wide Web (WWW) searching of the computer database (maintained under the SLAC-SPIRES system) that contains the summaries. This report contains full summaries of 180 approved current and recent experiments in elementary particle physics. The focus of the report is on selected experiments which directly contribute to our better understanding of elementary particles and their properties such as masses, widths or lifetimes, and branching fractions.

Galic, H.; Lehar, F.; Klyukhin, V.I.; Ryabov, Yu.G.; Bilak, S.V.; Illarionova, N.S.; Khachaturov, B.A.; Strokovsky, E.A.; Hoffman, C.M.; Kettle, P.-R.; Olin, A.; Armstrong, F.E.

1996-09-01

172

Physics of the Blues: Music, Fourier and Wave - Particle Duality

Art and science are intimately connected. There is probably no art that reveals this more than music. Music can be used as a tool to teach physics and engineering to non-scientists, illustrating such diverse concepts as Fourier analysis and quantum mechanics. This colloquium is aimed in reverse, to explain some interesting aspects of music to physicists. Topics include: What determines the frequency of notes on a musical scale? What is harmony and why would Fourier care? Where did the blues come from? (We' re talking the 'physics of the blues', and not 'the blues of physics' - that's another colloquium). Is there a musical particle? The presentation will be accompanied by live keyboard demonstrations. The presenter will attempt to draw tenuous connections between the subject of his talk and his day job as Director of the Advanced Photon Source at Argonne National Laboratory.

Gibson, J. Murray (ANL) [ANL

2003-10-15

173

Physics of the Blues: Music, Fourier and Wave - Particle Duality

Art and science are intimately connected. There is probably no art that reveals this more than music. Music can be used as a tool to teach physics and engineering to non-scientists, illustrating such diverse concepts as Fourier analysis and quantum mechanics. This colloquium is aimed in reverse, to explain some interesting aspects of music to physicists. Topics include: What determines the frequency of notes on a musical scale? What is harmony and why would Fourier care? Where did the blues come from? (We' re talking the 'physics of the blues', and not 'the blues of physics' - that's another colloquium). Is there a musical particle? The presentation will be accompanied by live keyboard demonstrations. The presenter will attempt to draw tenuous connections between the subject of his talk and his day job as Director of the Advanced Photon Source at Argonne National Laboratory.

174

NASA Astrophysics Data System (ADS)

A common learning goal for modern physics instructors is for students to recognize a difference between the experimental uncertainty of classical physics and the fundamental uncertainty of quantum mechanics. Our studies suggest this notoriously difficult task may be frustrated by the intuitively realist perspectives of introductory students, and a lack of ontological flexibility in their conceptions of light and matter. We have developed a framework for understanding and characterizing student perspectives on the physical interpretation of quantum mechanics, and demonstrate the differential impact on student thinking of the myriad ways instructors approach interpretive themes in their introductory courses. Like expert physicists, students interpret quantum phenomena differently, and these interpretations are significantly influenced by their overall stances on questions central to the so-called measurement problem: Is the wave function physically real, or simply a mathematical tool? Is the collapse of the wave function an ad hoc rule, or a physical transition not described by any equation? Does an electron, being a form of matter, exist as a localized particle at all times? These questions, which are of personal and academic interest to our students, are largely only superficially addressed in our introductory courses, often for fear of opening a Pandora's Box of student questions, none of which have easy answers. We show how a transformed modern physics curriculum (recently implemented at the University of Colorado) may positively impact student perspectives on indeterminacy and wave-particle duality, by making questions of classical and quantum reality a central theme of our course, but also by making the beliefs of our students, and not just those of scientists, an explicit topic of discussion.

Baily, Charles Raymond

175

Quantum Dots: An Experiment for Physical or Materials Chemistry

ERIC Educational Resources Information Center

An experiment is conducted for obtaining quantum dots for physical or materials chemistry. This experiment serves to both reinforce the basic concept of quantum confinement and providing a useful bridge between the molecular and solid-state world.

Winkler, L. D.; Arceo, J. F.; Hughes, W. C.; DeGraff, B. A.; Augustine, B. H.

2005-01-01

176

Puzzles in Hadronic Physics and Novel Quantum Chromodynamics Phenomenology.

National Technical Information Service (NTIS)

Quantum chromodynamics (QCD) is believed to be the underlying theory of hadron and nuclear physics. It provides a fundamental description of the structure of hadrons and nuclei in terms of elementary quark and gluon fields, just as quantum electrodynamics...

G. de Teramond M. Karliner S. J. Brodsky

2012-01-01

177

Particle physics: recent successes and future prospects

There is no doubt that as yet we do not have an ultimate theory of matter and forces in spite of the remarkable successes of the past decade. In this talk the author attempts to summarize briefly the historical background that led us to the present level of understanding, or more specifically to the standard model of particle physics. Subsequently the author describes several difficulties with this picture, continues with some possible indications of new physics, and finally ends with the discussion of the prospects for the future. 32 references.

Wojcicki, S.

1984-12-01

178

Current experiments in elementary particle physics. Revised

This report contains summaries of 584 current and recent experiments in elementary particle physics. Experiments that finished taking data before 1986 are excluded. Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Tokyo Institute of Nuclear Studies, Moscow Institute of Theoretical and Experimental Physics, KEK, LAMPF, Novosibirsk, Paul Scherrer Institut (PSI), Saclay, Serpukhov, SLAC, SSCL, and TRIUMF, and also several underground and underwater experiments. Instructions are given for remote searching of the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

Galic, H. [Stanford Univ., CA (United States). Stanford Linear Accelerator Center; Wohl, C.G.; Armstrong, B. [Lawrence Berkeley Lab., CA (United States); Dodder, D.C. [Los Alamos National Lab., NM (United States); Klyukhin, V.I.; Ryabov, Yu.G. [Inst. for High Energy Physics, Serpukhov (Russian Federation); Illarionova, N.S. [Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation); Lehar, F. [CEN Saclay, Gif-sur-Yvette (France); Oyanagi, Y. [Univ. of Tokyo (Japan). Faculty of Sciences; Olin, A. [TRIUMF, Vancouver, BC (Canada); Frosch, R. [Paul Scherrer Inst., Villigen (Switzerland)

1992-06-01

179

Particle Physics from Almost-Commutative Spacetimes

NASA Astrophysics Data System (ADS)

Our aim in this review paper is to present the applications of Connes' noncommutative geometry to elementary particle physics. Whereas the existing literature is mostly focused on a mathematical audience, in this paper we introduce the ideas and concepts from noncommutative geometry using physicists' terminology, gearing towards the predictions that can be derived from the noncommutative description. Focusing on a light package of noncommutative geometry (so-called "almost-commutative manifolds"), we shall introduce in steps: electrodynamics, the electroweak model, culminating in the full Standard Model. We hope that our approach helps in understanding the role noncommutative geometry could play in describing particle physics models, eventually unifying them with Einstein's (geometrical) theory of gravity.

van den Dungen, Koen; van Suijlekom, Walter D.

2012-10-01

180

Reflection of a particle from a quantum measurement

NASA Astrophysics Data System (ADS)

We present a generalization of continuous position measurements that accounts for a spatially inhomogeneous measurement strength. This describes many real measurement scenarios, in which the rate at which information is extracted about position has itself a spatial profile, and includes measurements that detect whether a particle has crossed from one region into another. We show that such measurements can be described, in their averaged behavior, as stochastically fluctuating potentials of vanishing time average. Reasonable constraints restrict the form of the measurement to have degenerate outcomes, which tend to drive the system to spatial superposition states. We present the results of quantum-trajectory simulations for measurements with a step-function profile (a 'which-way' measurement) and a Gaussian profile. We find that the particle can coherently reflect from the measurement region in both cases, despite the stochastic nature of the measurement back-action. In addition, we explore the connection to the quantum Zeno effect, where we find that the reflection probability tends to unity as the measurement strength increases. Finally, we discuss two physical realizations of a spatially varying position measurement using atoms.

Mackrory, Jonathan B.; Jacobs, Kurt; Steck, Daniel A.

2010-11-01

181

Current experiments in elementary-particle physics

NASA Astrophysics Data System (ADS)

Microfiche are included which contain summaries of 479 experiments in elementary particle physics. Experiments are included at the following laboratories: Brookhaven (ENL); CERN; DESY; Fermilab. (FNAL); Institute for Nuclear Studies (INS); KEK; LAMPF; Serpukhov (SERP); SIN; SLAC; and TRIUMP. Also, summries of proton decay experiments are included. A list of experiments and titles is included; and a beam-target-momentum index and a spokesperson index are given. Properties of beams at the facilities are tabulated.

Wohl, C. G.; Armstrong, F. E.; Rittenberg, A.

1983-03-01

182

Charting the Course for Elementary Particle Physics

''It was the best of times; it was the worst of times'' is the way Dickens begins the Tale of Two Cities. The line is appropriate to our time in particle physics. It is the best of times because we are in the midst of a revolution in understanding, the third to occur during my career. It is the worst of times because accelerator facilities are shutting down before new ones are opening, restricting the opportunity for experiments, and because of great uncertainty about future funding. My task today is to give you a view of the most important opportunities for our field under a scenario that is constrained by a tight budget. It is a time when we cannot afford the merely good, but must give first priority to the really important. The defining theme of particle physics is to learn what the universe is made of and how it all works. This definition spans the full range of size from the largest things to the smallest things. This particle physics revolution has its origins in experiments that look at both.

Richter, Burton

2007-02-20

183

Nuclear and particle physics in the early universe

NASA Technical Reports Server (NTRS)

Basic principles and implications of Big Bang cosmology are reviewed, noting the physical evidence of a previous universe temperature of 10,000 K and theoretical arguments such as grand unification decoupling indicating a primal temperature of 10 to the 15th eV. The Planck time of 10 to the -43rd sec after the Big Bang is set as the limit before which gravity was quantized and nothing is known. Gauge theories of elementary particle physics are reviewed for successful predictions of similarity in weak and electromagnetic interactions and quantum chromodynamic predictions for strong interactions. The large number of photons in the universe relative to the baryons is considered and the grand unified theories are cited as showing the existence of baryon nonconservation as an explanation. Further attention is given to quark-hadron phase transition, the decoupling for the weak interaction and relic neutrinos, and Big Bang nucleosynthesis.

Schramm, D. N.

1981-01-01

184

Persistent Currents and Quantum Critical Phenomena in Mesoscopic Physics

NASA Astrophysics Data System (ADS)

In this thesis, we study persistent currents and quantum critical phenomena in the systems of mesoscopic physics. As an introduction in Chapter 1 we familiarize the reader with the area of mesoscopic physics. We explain how mesoscopic systems are different from quantum systems of single atoms and molecules and bulk systems with an Avogadro number of elements. We also describe some important mesoscopic phenomena. One of the mathematical tools that we extensively use in our studies is Random Matrix Theorty. This theory is not a part of standard physics courses and for educational purposes we provide the basics of Random Matrix Theory in Chapter 2. In Chapter 3 we study the persistent current of noninteracting electrons in quantum billiards. We consider simply connected chaotic Robnik-Berry quantum billiard and its annular analog. The electrons move in the presence of a point-like magnetic flux at the center of the billiard. For the simply connected billiard, we find a large diamagnetic contribution to the persistent current at small flux, which is independent of the flux and is proportional to the number of electrons (or equivalently the density since we keep the area fixed). The size of this diamagnetic contribution is much larger than the previously studied mesoscopic fluctuations in the persistent current in the simply connected billiard. This behavior of persistent current can ultimately be traced to the response of the angular-momentum l = 0 levels (neglected in semiclassical expansions) on the unit disk to a point-like flux at its center. We observe the same behavior for the annular billiard when the inner radius is much smaller than the outer one. We also find that the usual fluctuating persistent current and Anderson-like localization due to boundary scattering are seen when the annulus tends to a one-dimensional ring. We explore the conditions for the observability of this phenomenon. In Chapter 4 we study quantum critical phenomena in a system of two coupled quantum dots connected by a hopping bridge. Both the dots and connecting region are assumed to be in universal Random Matrix crossover regimes between Gaussian orthogonal and unitary ensembles (defined in Chapter 2). We exploit a diagrammatic approach appropriate for energy separations much larger than the level spacing, to obtain the ensemble-averaged one- and two-particle Greens functions. We find that two main components of the two-particle Green's function (diffuson and Cooperon) can be described by separate scaling functions. We then use this information to investigate a model interacting system in which one dot has an attractive s-wave reduced Bardeen-Cooper-Schrieffer interaction, while the other is noninteracting but subject to an orbital magnetic field. We find that the critical temperature TC of the mean-field transition into the superconducting state in the first dot is non-monotonic in the flux through the second dot in a certain regime of interdot coupling. Likewise, the fluctuation magnetization above the critical temperature is also non-monotonic in this regime, can be either diamagnetic or paramagnetic, and can be deduced from the Cooperon scaling function. We end this thesis with conclusion in Chapter 5. KEYWORDS: quantum dot, crossover, quantum criticality, persistent current, quantum billiard

Zelyak, Oleksandr

185

Studies in theoretical high energy particle physics. [Dept. of Physics, Univ. of Illinois at Chicago

Theoretical work on the following topics is briefly summarized: symmetry structure of conformal affine Toda model and KP hierarchy; solitons in the affine Toda and conformal affine Toda models; classical r-matrices and Poisson bracket structures on infinite-dimensional groups; R-matrix formulation of KP hierarchies and their gauge equivalence; statistics of particles and solitons; charge quantization in the presence of an Alice string; knotting and linking of nonabelian flux; electric dipole moments; neutrino physics in gauge theories; CP violation in the high energy colliders; supersymmetric quantum mechanics; parton structure functions in nuclei; dual parton model. 38 refs.

Aratyn, H.; Brekke, L.; Keung, Wai-Yee; Sukhatme, U.

1993-01-01

186

Cognitive Mapping of Advanced Level Physics Students' Conceptions of Quantum Physics.

ERIC Educational Resources Information Center

This paper presents findings from a study that investigated students' understanding of quantum phenomena and focused on how students incorporate the ideas of quantum physics into their overall cognitive framework. The heuristic metaphor of the map is used to construct graphic representations of students' understanding of quantum physics. The…

Mashhadi, Azam; Woolnough, Brian

187

Cyclic Polyynes as Examples of the Quantum Mechanical Particle on a Ring

ERIC Educational Resources Information Center

Many quantum mechanical models are discussed as part of the undergraduate physical chemistry course to help students understand the connection between eigenvalue expressions and spectroscopy. Typical examples covered include the particle in a box, the harmonic oscillator, the rigid rotor, and the hydrogen atom. This article demonstrates that…

Anderson, Bruce D.

2012-01-01

188

Quantum-Mechanics of a Spinless Particle in Combined Coulomb and Harmonic Oscillator Potentials

In this dissertation the quantum mechanics of a spinless particle in a combined Coulomb and harmonic oscillator potential is discussed. The particular potential considered is a 2:1 anisotropic harmonic oscillator combined with a concentric Coulomb potential. These two potentials are the two most studied potentials in mathematical physics. It is shown that this combined potential gives a Schrodinger equation which

Samuel Ernest Stansfield

1986-01-01

189

Physics through the 1990s: Elementary-particle physics

NASA Technical Reports Server (NTRS)

The volume begins with a non-mathematical discussion of the motivation behind, and basic ideas of, elementary-particle physics theory and experiment. The progress over the past two decades with the quark model and unification of the electromagnetic and weak interactions is reviewed. Existing theoretical problems in the field, such as the origin of mass and the unification of the fundamental forces, are detailed, along with experimental programs to test the new theories. Accelerators, instrumentation, and detectors are described for both current and future facilities. Interactions with other areas of both theoretical and applied physics are presented. The sociology of the field is examined regarding the education of graduate students, the organization necessary in large-scale experiments, and the decision-making process involved in high-cost experiments. Finally, conclusions and recommendations for maintaining US excellence in theory and experiment are given. Appendices list both current and planned accelerators, and present statistical data on the US elementary-particle physics program. A glossary is included.

1986-01-01

190

Ether, the Theory of Relativity and Quantum Physics

NASA Astrophysics Data System (ADS)

In this paper we revisit some of the reasons given by Einstein that resulted in his change of mind about the ether from denying to defending its existence. The ether proposed by Einstein we call Einstein's new ether. We consider the potential use of Einstein's new ether in quantum mechanics. The standard model of elementary particles reveals the existence of at least one component of Einstein's new ether. In this work we explore additional properties of Einstein's new ether. In particular, we consider a recent experiment known as the Afshar experiment due to its implications for the wave particle duality paradox. The Afshar experiment is perhaps the first experiment that provides clear evidence that wave and particle aspects of the photon have some sort of physical reality beyond the limits imposed by complementarity. We propose that the physical reality of the wave aspect of the photon has its origin in Einstein's new ether. Here, we report on consequences of the Afshar experiment for Einstein's new ether.

Flores, Eduardo V.

191

National Technical Information Service (NTIS)

This publication contains the papers presented during the 14. national meeting on particle physics and fields. Works on the areas of gravitation, cosmology, quantum mechanics, string models; symmetry, current algebras, interaction models; particle decays ...

1994-01-01

192

National Technical Information Service (NTIS)

This publication contains the Proceedings presented during the 12. National Meeting on Particle Physics and Fields. Works on the areas of gravitation, quantum mechanics, string models; symmetry, current algebras, interaction models; particle decays, and t...

A. L. Santos E. R. B. Mello J. A. M. Simoes J. A. Chinellato V. Pleitez

1993-01-01

193

Quantum contextuality for a relativistic spin-1/2 particle

NASA Astrophysics Data System (ADS)

The quantum predictions for a single nonrelativistic spin-1/2 particle can be reproduced by noncontextual hidden variables. Here we show that quantum contextuality for a relativistic electron moving in a Coulomb potential naturally emerges if relativistic effects are taken into account. The contextuality can be identified through the violation of noncontextuality inequalities. We also discuss quantum contextuality for the free Dirac electron as well as the relativistic Dirac oscillator.

Chen, Jing-Ling; Su, Hong-Yi; Wu, Chunfeng; Deng, Dong-Ling; Cabello, Adán; Kwek, L. C.; Oh, C. H.

2013-02-01

194

Characterization of Particle States in Relativistic Classical Quantum Theory.

National Technical Information Service (NTIS)

Classical and quantum relativistic mechanics are studied. The notion of a ''particle'' is defined in the classical case and the interpretation of mechanics in space-time is clarified. These notions are carried over to the quantum theory, as much as possib...

L. P. Horwitz Y. Rabin

1977-01-01

195

Equivalence Postulate and the Quantum Potential of Two Free Particles

Commutativity of the diagram of the maps connecting three one--particle\\u000astate, implied by the Equivalence Postulate (EP), gives a cocycle condition\\u000awhich unequivocally leads to the quantum Hamilton--Jacobi equation. Energy\\u000aquantization is a direct consequences of the local homeomorphicity of the\\u000atrivializing map. We review the EP and show that the quantum potential for two\\u000afree particles, which depends on

Marco Matone; G. Galilei

2002-01-01

196

Strings as multi-particle states of quantum sigma-models

We study the quantum Bethe ansatz equations in the O(2n) sigma-model for physical particles on a circle, with the interaction given by the Zamolodchikovs'S-matrix, in view of its application to quantization of the string on the S2n?1×Rt space. For a finite number of particles, the system looks like an inhomogeneous integrable O(2n) spin chain. Similarly to OSp(2m+n|2m) conformal sigma-model considered

Nikolay Gromov; Vladimir Kazakov; Kazuhiro Sakai; Pedro Vieira

2007-01-01

197

Physics and applications of self-assembled quantum dots

Linear and nonlinear spectroscopic invsetigations of self-assembled quantum dots open up the possibility to study model quantum mechanical systems with potential applications in solid-state based quantum information processing. In this article we review recent advances in our understanding of the physics of self-assembled quantum dots and novel devices based upon them. We focus our attention on four key areas: (i)

E. Beham; M. Betz; S. Trumm; M. Kroutvar; Y. Ducommun; H. J. Krenner; M. Bichler; A. Leitenstorfer; J. J. Finley; A. Zrenner; G. Abstreiter

2004-01-01

198

BOOK REVIEW: Quantum Physics in One Dimension

NASA Astrophysics Data System (ADS)

To a casual ostrich the world of quantum physics in one dimension may sound a little one-dimensional, suitable perhaps for those with an unhealthy obsession for the esoteric. Nothing of course could be further from the truth. The field is remarkably rich and broad, and for more than fifty years has thrown up innumerable challenges. Theorists, realising that the role of interactions in 1D is special and that well known paradigms of higher dimensions (Fermi liquid theory for example) no longer apply, took up the challenge of developing new concepts and techniques to understand the undoubted pecularities of one-dimensional systems. And experimentalists have succeeded in turning pipe dreams into reality, producing an impressive and ever increasing array of experimental realizations of 1D systems, from the molecular to the mesoscopic---spin and ladder compounds, organic superconductors, carbon nanotubes, quantum wires, Josephson junction arrays and so on. Many books on the theory of one-dimensional systems are however written by experts for experts, and tend as such to leave the non-specialist a touch bewildered. This is understandable on both fronts, for the underlying theoretical techniques are unquestionably sophisticated and not usually part of standard courses in many-body theory. A brave author it is then who aims to produce a well rounded, if necessarily partial, overview of quantum physics in one dimension, accessible to a beginner yet taking them to the edge of current research, and providing en route a thorough grounding in the fundamental ideas, basic methods and essential phenomenology of the field. It is of course the brave who succeed in this world, and Thierry Giamarchi does just that with this excellent book, written by an expert for the uninitiated. Aimed in particular at graduate students in theoretical condensed matter physics, and assumimg little theoretical background on the part of the reader (well just a little), Giamarchi writes in a refreshingly relaxed style with infectious enthusiasm for his subject, and readily combines formal instruction with physical insight. The result is a serious, pedagogical yet comprehensive guide to the fascinating and important field of one-dimensional quantum systems, for which many a graduate student (and not a few oldies) will be grateful. The first half of the book, chapters 1--5, is devoted to a coherent presentation of the essential concepts and theoretical methods of the field. After a basic introduction to the unique behaviour of interacting electrons in one dimension, and to early fermionic approaches to the problem, Giamarchi turns to the technique of bosonization, introducing chapter 3 with a Marxist quote: `A child of five would understand this. Send for a child of five.' This most powerful technique is presented in a step by step fashion, and serious perusal of the chapter will benefit all ages since bosonization is used extensively throughout the rest of the book. The same is true of chapter 3 where a phenomenological and physically insightful introduction is given to the Luttinger liquid---the key concept in the low-energy physics of one-dimensional systems, analogous to the Fermi liquid in higher dimensions. Chapter 4 deals with what the author calls `refinements', or complications of the sort theorists in particular welcome; such as how the Luttinger liquid description is modified by the presence of long-ranged interactions, the Mott transition (`we forgot the lattice Gromit'), and the effects of breaking spin rotational invariance on application of a magnetic field. Finally chapter 5 describes various microscopic methods for one dimension, including a brief discussion of numerical techniques but focussing primarily on the Bethe ansatz---the famous one-dimensional technique others seek to emulate but whose well known complexity necessitates a relatively brief discussion, confined in practice to the spin-1/2 Heisenberg model. In the second half of the book, chapters 6--11, a range of different physical realizations of one-dimensional quantum physics are dis

Logan, David

2004-05-01

199

Experimental particle physics. [Dept. of Physics, Drexel Univ

The goals of this research are the experimental testing of fundamental theories of physics beyond the standard model and the exploration of cosmic phenomena through the techniques of particle physics. We are working on the MACRO experiment, which employs a large-area underground detector to search fore grand unification magnetic monopoles and dark matter candidates and to study cosmic ray muons as well as low- and high-energy neutrinos; the Chooz experiment to search for reactor neutrino oscillations at a distance of 1 km from the source; a new proposal (the Perry experiment) to construct a one-kiloton liquid scintillator in the Fairport, Ohio underground facility IMB to study neutrino oscillations with a 13 km baseline; and development of technology for improved liquid scintillators and for very-low-background materials in support of the MACRO and Perry experiments and for new solar neutrino experiments.

Steinberg, R.I.; Lane, C.E.

1992-09-01

200

Blind Analysis in Nuclear and Particle Physics

NASA Astrophysics Data System (ADS)

During the past decade, blind analysis has become a widely used tool in nuclear and particle physics measurements. A blind analysis avoids the possibility of experimenters biasing their result toward their own preconceptions by preventing them from knowing the answer until the analysis is complete. There is at least circumstantial evidence that such a bias has affected past measurements, and as experiments have become costlier and more difficult and hence harder to reproduce, the possibility of bias has become a more important issue than in the past. We describe here the motivations for performing a blind analysis, and give several modern examples of successful blind analysis strategies.

Klein, Joshua R.; Roodman, Aaron

2005-12-01

201

Proof-of-concept experiments for quantum physics in space

Quantum physics experiments in space using entangled photons and satellites are within reach of current technology. We propose a series of fundamental quantum physics experiments that make advantageous use of the space infrastructure with specific emphasis on the satellite-based distribution of entangled photon pairs. The experiments are feasible already today and will eventually lead to a Bell-experiment over thousands of

Rainer Kaltenbaek; Markus Aspelmeyer; Thomas Jennewein; Caslav Brukner; Anton Zeilinger; Martin Pfennigbauer; Walter R. Leeb

2004-01-01

202

Inner-Shell Physics after Fifty Years of Quantum Mechanics.

National Technical Information Service (NTIS)

A historical view is given of how the development of quantum mechanics has been affected by the information relating to inner shells, gathered by physicists since the early days of atomic physics, and of the impact of quantum mechanics on the physics of i...

E. Merzbacher

1976-01-01

203

Physical and circuit modeling of coupled open quantum systems

Recently, we proposed new complementary logic circuits using nano-scale coupled quantum wells [12]. In this paper, we explore a systematic way of modeling the device at physical and circuit levels for nano-scale coupled open quantum systems. The physical interface between coupled and uncoupled regions is considered as a junction where electrons can be coherently injected. The circuit model treats the

Yasunao Katayama

2005-01-01

204

(Medium energy particle physics): Annual progress report

Investigations currently carried out by the UCLA Particle Physics Research Group can be arranged into four programs: Pion-Nucleon Scattering; Tests of Charge Symmetry and Isospin Invariance; Light Nuclei (Strong Form Factors of /sup 3/H, /sup 3/He, /sup 4/He; Detailed Balance in pd /r reversible/ /gamma//sup 3/H; Interaction Dynamics); and Search for the Rare Decay /Mu//sup +/ /yields/ e/sup +/ + /gamma/ (MEGA). The general considerations which led to the choice of physics problems investigated by our group are given in the next section. We also outline the scope of the research being done which includes over a dozen experiments. The main body of this report details the research carried out in the past year, the status of various experiments, and new projects.

Nefkens, B.M.K.

1985-10-01

205

Dirac particle in a box, and relativistic quantum Zeno dynamics

NASA Astrophysics Data System (ADS)

After developing a complete set of eigenfunctions for a Dirac particle restricted to a box, the quantum Zeno dynamics of a relativistic system is considered. The evolution of a continuously observed quantum mechanical system is governed by the theorem put forth by Misra and Sudarshan. One of the conditions for quantum Zeno dynamics to be manifest is that the Hamiltonian is semi-bounded. This Letter analyzes the effects of continuous observation of a particle whose time evolution is generated by the Dirac Hamiltonian. The theorem by Misra and Sudarshan is not applicable here since the Dirac operator is not semi-bounded.

Menon, Govind; Belyi, Sergey

2004-09-01

206

Particle-hole symmetry in the quantum Hall transport

NASA Astrophysics Data System (ADS)

Particle-hole symmetry is a central concept in the quantum Hall effects and is invoked to explain the observation of incompressible quantum Hall states for symmetric filling factors ? ? 1 - ?. We report finite-bias measurements of the current transmission through a split-gate constriction in the quantum Hall regime displaying signatures linked to the presence of this symmetry. Experimental data are also discussed in light of the Luttinger model for edge channels. We show how particle-hole duality can be exploited to design QH circuits where transport can be more easily interpreted in terms of ``holes'' in a filled Landau level.

Roddaro, S.; Pellegrini, V.; Beltram, F.; West, K. W.; Pfeiffer, L. N.

2007-04-01

207

Quantum Entanglement in Random Physical States

NASA Astrophysics Data System (ADS)

Most states in the Hilbert space are maximally entangled. This fact has proven useful to investigate—among other things—the foundations of statistical mechanics. Unfortunately, most states in the Hilbert space of a quantum many-body system are not physically accessible. We define physical ensembles of states acting on random factorized states by a circuit of length k of random and independent unitaries with local support. We study the typicality of entanglement by means of the purity of the reduced state. We find that for a time k=O(1), the typical purity obeys the area law. Thus, the upper bounds for area law are actually saturated, on average, with a variance that goes to zero for large systems. Similarly, we prove that by means of local evolution a subsystem of linear dimensions L is typically entangled with a volume law when the time scales with the size of the subsystem. Moreover, we show that for large values of k the reduced state becomes very close to the completely mixed state.

Hamma, Alioscia; Santra, Siddhartha; Zanardi, Paolo

2012-07-01

208

Teaching and understanding of quantum interpretations in modern physics courses

NSDL National Science Digital Library

Just as expert physicists vary in their personal stances on interpretation in quantum mechanics, instructors vary on whether and how to teach interpretations of quantum phenomena in introductory modern physics courses. In this paper, we document variations in instructional approaches with respect to interpretation in two similar modern physics courses recently taught at the University of Colorado, and examine associated impacts on student perspectives regarding quantum physics. We find students are more likely to prefer realist interpretations of quantum-mechanical systems when instructors are less explicit in addressing student ontologies. We also observe contextual variations in student beliefs about quantum systems, indicating that instructors who choose to address questions of ontology in quantum mechanics should do so explicitly across a range of topics.

Baily, Charles; Finkelstein, Noah D.

2010-03-11

209

Quantum physics: Watching the wavefunction collapse

NASA Astrophysics Data System (ADS)

The continuous random path of a superconducting system's quantum state has been tracked as the state changes during measurement. The results open the possibility of steering quantum systems into a desired state. See Letter p.211

Jordan, Andrew N.

2013-10-01

210

Quantum Field Theory in Condensed Matter Physics

NASA Astrophysics Data System (ADS)

Preface; Acknowledgements; Part I. Introduction to Methods: 1. QFT: language and goals; 2. Connection between quantum and classical: path integrals; 3. Definitions of correlation functions: Wick's theorem; 4. Free bosonic field in an external field; 5. Perturbation theory: Feynman diagrams; 6. Calculation methods for diagram series: divergences and their elimination; 7. Renormalization group procedures; 8. O(N)-symmetric vector model below the transition point; 9. Nonlinear sigma models in two dimensions: renormalization group and 1/N-expansion; 10. O(3) nonlinear sigma model in the strong coupling limit; Part II. Fermions: 11. Path integral and Wick's theorem for fermions; 12. Interaction electrons: the Fermi liquid; 13. Electrodynamics in metals; 14. Relativistic fermions: aspects of quantum electrodynamics; 15. Aharonov-Bohm effect and transmutation of statistics; Part III. Strongly Fluctuating Spin Systems: Introduction; 16. Schwinger-Wigner quantization procedure: nonlinear sigma models; 17. O(3) nonlinear sigma model in (2+1) dimensions: the phase diagram; 18. Order from disorder; 19. Jordan-Wigner transformations for spin S=1/2 models in D=1, 2, 3; 20. Majorana representation for spin S=1/2 magnets: relationship to Z2 lattice gauge theories; 21. Path integral representations for a doped antiferromagnet; Part IV. Physics in the World of One Spatial Dimension: Introduction; 22. Model of the free bosonic massless scalar field; 23. Relevant and irrelevant fields; 24. Kosterlitz-Thouless transition; 25. Conformal symmetry; 26. Virasoro algebra; 27. Differential equations for the correlation functions; 28. Ising model; 29. One-dimensional spinless fermions: Tomonaga-Luttinger liquid; 30. One-dimensional fermions with spin: spin-charge separation; 31. Kac-Moody algebras: Wess-Zumino-Novikov-Witten model; 32. Wess-Zumino-Novikov-Witten model in the Lagrangian form: non-Abelian bosonization; 33. Semiclassical approach to Wess-Zumino-Novikov-Witten models; 34. Integrable models: dynamical mass generation; 35. A comparative study of dynamical mass generation in one and three dimensions; 36. One-dimensional spin liquids: spin ladder and spin S=1 Heisenberg chain; 37. Kondo chain; 38. Gauge fixing in non-Abelian theories: (1+1)-dimensional quantum chromodynamics; Select bibliography; Index.

Tsvelik, Alexei M.

2007-01-01

211

Quantum limited particle sensing in optical tweezers

Particle sensing in optical tweezers systems provides information on the position, velocity, and force of the specimen particles. The conventional quadrant detection scheme is applied ubiquitously in optical tweezers experiments to quantify these parameters. In this paper, we show that quadrant detection is nonoptimal for particle sensing in optical tweezers and propose an alternative optimal particle sensing scheme based on spatial homodyne detection. A formalism for particle sensing in terms of transverse spatial modes is developed and numerical simulations of the efficacies of both quadrant and spatial homodyne detection are shown. We demonstrate that 1 order of magnitude improvement in particle sensing sensitivity can be achieved using spatial homodyne over quadrant detection.

Tay, J.W. [Jack Dodd Centre for Photonics and Ultracold Atoms, Department of Physics, University of Otago, Dunedin (New Zealand); Hsu, Magnus T. L. [School of Mathematics and Physics, University of Queensland, St. Lucia, Queensland 4072 (Australia); Bowen, Warwick P. [Jack Dodd Centre for Photonics and Ultracold Atoms, Department of Physics, University of Otago, Dunedin (New Zealand); School of Mathematics and Physics, University of Queensland, St. Lucia, Queensland 4072 (Australia)

2009-12-15

212

Particle physics models at the electroweak scale and beyond

NASA Astrophysics Data System (ADS)

We consider various particle physics models constructed to address issues in electroweak-scale supersymmetry, grand unification, and inflation. We begin by exploring the phenomenology of a supersymmetric SU(5) theory living in a truncated, warped 5-dimensional spacetime, with the gauge group broken down to the Standard Model at both ends. The low-energy spectrum of this setup is exotic, and in particular includes a particle of O (TeV) mass with the quantum numbers of an off diagonal SU(5) adjoint. Via the AdS/CFT correspondence, this is interpreted as a pseudo-Goldstone boson of a broken global symmetry within the strongly-coupled sector responsible for supersymmetry breaking. We consider the phenomenology of such a particle in some detail, including collider signals and cosmology. We proceed to consider a generic framework for ameliorating fine-tuning in the Minimal Supersymmetric Standard Model, utilizing new contributions to the Higgs boson mass. We demonstrate this idea with two explicit models. Returning to warped spacetime, we then demonstrate the feasibility of applying AdS/CFT ideas to the breaking of grand unified theories. In this context, the warped spacetime description is dual to a strong gauge sector which develops condensates and breaks the unified gauge group into which the Standard Model is embedded. Finally, we consider the generation of primordial density perturbations in the model of chain inflation, utilizing a combination of analytic and numerical techniques.

Tweedie, Brock Adam

213

Energy related applications of elementary particle physics

The current research position is summarized, and what could be done in the future to clarify issues which were opened up by the research is indicated. Following on the discussion of the viability of catalyzed fusion, there is presented along with the key experimental results, a short account of the physics surrounding the subject. This is followed by a discussion of key research topics addressed. In consequence of the progress made, it appears that the feasibility of a small-scale fusion based on catalyzed reactions rests on either the remote chance that a yet undiscovered ultraheavy negatively charged elementary particle exists in Nature, or on the possible technical realization of a system based on muon-catalyzed fusion (MuCF) in high-density degenerate hydrogen plasma (density 1000 LHD, temperature O(100 eV)). The lattter is considered to have practical promise.

Rafelski, J.

1991-08-31

214

Interpretive Themes in Quantum Physics: Curriculum Development and Outcomes

NSDL National Science Digital Library

A common learning goal for modern physics instructors is for students to recognize a difference between the experimental uncertainty of classical physics and the fundamental uncertainty of quantum mechanics. Our prior work has shown that student perspectives on the physical interpretation of quantum mechanics can be characterized, and are differentially influenced by the myriad ways instructors approach interpretive themes in their introductory courses. We report how a transformed modern physics curriculum (recently implemented at the University of Colorado) has positively impacted student perspectives on quantum physics, by making questions of classical and quantum reality a central theme of the course, but also by making the beliefs of students (and not just those of scientists) an explicit topic of discussion.

Baily, Charles; Finkelstein, Noah D.

2012-04-24

215

Particle physics---Experimental. Annual progress report

We are continuing a research program in particle astrophysics and high energy experimental particle physics. We have joined the DUMAND Collaboration, which is constructing a deep undersea astrophysical neutrino detector near Hawaii. Studies of high energy hadronic interactions using emulsion chamber techniques were also continued, using balloon flight exposures to ultra-high cosmic ray nuclei (JACEE) and accelerator beams. As members of the DUMAND Collaboration, we have responsibility for development a construction of critical components for the deep undersea neutrino detector facility. We have designed and developed the acoustical positioning system required to permit reconstruction of muon tracks with sufficient precision to meet the astrophysical goals of the experiment. In addition, we are making significant contributions to the design of the database and triggering system to be used. Work has been continuing in other aspects of the study of multiparticle production processes in nuclei. We are participants in a joint US/Japan program to study nuclear interactions at energies two orders of magnitude greater than those of existing accelerators, using balloon-borne emulsion chambers. On one of the flights we found two nuclear interactions of multiplicity over 1000 -- one with a multiplicity of over 2000 and pseudorapidity density {approximately} 800 in the central region. At the statistical level of the JACEE experiment, the frequency of occurrence of such events is orders of magnitude too large. We have continued our ongoing program to study hadronic interactions in emulsions exposed to high energy accelerator beams.

Lord, J.J.; Boynton, P.E.; Burnett, T.H.; Wilkes, R.J.

1991-08-21

216

NASA Astrophysics Data System (ADS)

This work first explicates the philosophy of classical and quantum fields and particles. I am interested in determining how science can have a metaphysical dimension, and then with the claim that the quantum revolution has an important metaphysical component. I argue that the metaphysical implications of a theory are properties of its models, as classical mechanics determines properties of atomic diversity and temporal continuity with its representations of distinct, continuous trajectories. It is often suggested that classical statistical physics requires that many particle states be represented so that permuting properties leads to distinct states; this implies that individuals can be reidentified across possible worlds in a non-qualitative way. I show there is no evidence for this conclusion, an important result, for it is claimed that quantum particles are not individuals. This claim is based on the misconception about classical statistics, but also on a conflation of notions of identity; I show that, while transworld identity is incompatible with quantum mechanics, other classical notions may be consistently ascribed. I also give a field-particle distinction that applies usefully in both quantum and classical domains. In the former the distinction helps defeat claims of underdetermined by data, in the latter it helps provide a minimal field metaphysics. Next I tackle renormalisation: I show how divergences occur in approximate, perturbative calculations, and demonstrate how finite, empirically verified, answers are obtained. These techniques seem to show that the predictions are not logical consequences of the exact theory. I use the techniques of the renormalisation group to establish that perturbative renormalised quantum field theory does indeed approximate the consequences of field theory. Finally, I discuss the idea (Cao and Schweber, 1994) that renormalisation proves that there can be no quantum theory of everything, only a patchwork of effective theories. The preceding chapter shows that renormalisation demonstrates only that the picture is consistent, and this is insufficient to show that physics must be phenomenological.

Huggett, Nick

1995-01-01

217

Matter and Interactions: A Particle Physics Perspective

ERIC Educational Resources Information Center

In classical mechanics, matter and fields are completely separated; matter interacts with fields. For particle physicists this is not the case; both matter and fields are represented by particles. Fundamental interactions are mediated by particles exchanged between matter particles. In this article we explain why particle physicists believe in…

Organtini, Giovanni

2011-01-01

218

Research accomplishments and future goals in particle physics

This document presents our proposal to continue the activities of Boston University researchers in eight projects in high energy physics research: Colliding Beams Physics; Accelerator Design Physics; MACRO Project; Proton Decay Project; Theoretical Particle Physics; Muon G-2 Project; and Hadron Collider Physics. The scope of each of these projects is presented in detail in this paper.

Whitaker, J.S.

1990-01-05

219

Particle Physics in a Season of Change

A digest of the authors opening remarks at the 2011 Hadron Collider Physics Symposium. I have chosen my title to reflect the transitions we are living through, in particle physics overall and in hadron collider physics in particular. Data-taking has ended at the Tevatron, with {approx} 12 fb{sup -1} of {bar p}p interactions delivered to CDF and D0 at {radical}s = 1.96 TeV. The Large Hadron Collider has registered a spectacular first full-year run, with ATLAS and CMS seeing > 5 fb{sup -1}, LHCb recording {approx} 1 fb{sup -1}, and ALICE logging nearly 5 pb{sup -1} of pp data at {radical}s = 7 TeV, plus a healthy dose of Pb-Pb collisions. The transition to a new energy regime and new realms of instantaneous luminosity exceeding 3.5 x 10{sup 33} cm{sup -2} s{sup -1} has brought the advantage of enhanced physics reach and the challenge of pile-up reaching {approx} 15 interactions per beam crossing. I am happy to record that what the experiments have (not) found so far has roused some of my theoretical colleagues from years of complacency and stimulated them to think anew about what the TeV scale might hold. We theorists have had plenty of time to explore many proposals for electroweak symmetry breaking and for new physics that might lie beyond established knowledge. With so many different theoretical inventions in circulation, it is in the nature of things that most will be wrong. Keep in mind that we learn from what experiment tells us is not there, even if it is uncommon to throw a party for ruling something out. Some non-observations may be especially telling: the persistent absence of flavor-changing neutral currents, for example, seems to me more and more an important clue that we have not yet deciphered. It is natural that the search for the avatar of electroweak symmetry breaking preoccupies participants and spectators alike. But it is essential to conceive the physics opportunities before us in their full richness. I would advocate a three-fold approach: Explore, Search, Measure! The first phase of running at the LHC has brought us to two new lands - in proton-proton and lead-lead collisions - and we may well enter other new lands with each change of energy or increase of sensitivity. I believe that it will prove very rewarding to spend some time simply exploring each new landscape, without strong preconceptions, to learn what is there and, perhaps, to encounter interesting surprises. Directed searches, for which we have made extensive preparations, are of self-evident interest. Here the challenge will be to broaden the searches over time, so the searches are not too narrowly directed. Our very successful conception of particles and forces is highly idealized. We have a great opportunity to learn just how comprehensive is our network of understanding by making precise measurements and probing for weak spots, or finding more sweeping accord between theory and experiment.

Quigg, Chris

2012-02-01

220

Quantum Tic-Tac-Toe as Metaphor for Quantum Physics

NASA Astrophysics Data System (ADS)

Quantum Tic-Tac-Toe is presented as an abstract quantum system derived from the rules of Classical Tic-Tac-Toe. Abstract quantum systems can be constructed from classical systems by the addition of three types of rules; rules of Superposition, rules of Entanglement, and rules of Collapse. This is formally done for Quantum Tic-Tac-Toe. As a part of this construction it is shown that abstract quantum systems can be viewed as an ensemble of classical systems. That is, the state of a quantum game implies a set of simultaneous classical games. The number and evolution of the ensemble of classical games is driven by the superposition, entanglement, and collapse rules. Various aspects and play situations provide excellent metaphors for standard features of quantum mechanics. Several of the more significant metaphors are discussed, including a measurement mechanism, the correspondence principle, Everett's Many Worlds Hypothesis, an ascertainity principle, and spooky action at a distance. Abstract quantum systems also show the consistency of backwards-in-time causality, and the influence on the present of both pasts and futures that never happened. The strongest logical argument against faster-than-light (FTL) phenomena is that since FTL implies backwards-in-time causality, temporal paradox is an unavoidable consequence of FTL; hence FTL is impossible. Since abstract quantum systems support backwards-in-time causality but avoid temporal paradox through pruning of the classical ensemble, it may be that quantum based FTL schemes are possible allowing backwards-in-time causality, but prohibiting temporal paradox.

Goff, Allan; Lehmann, Dale; Siegel, Joel

2004-02-01

221

Puzzles in Hadronic Physics and Novel Quantum Chromodynamics Phenomenology

NASA Astrophysics Data System (ADS)

We review some outstanding puzzles and experimental anomalies in hadron physics that appear to challenge conventional wisdom and, in some cases, the foundations of quantum chromodynamics (QCD). We also discuss possible solutions and propose new tests and experiments that could illuminate the underlying physics and novel phenomenological features of QCD. In some cases, new perspectives for QCD physics have emerged.

Brodsky, Stanley J.; de Téramond, Guy; Karliner, Marek

2012-11-01

222

Time and a physical Hamiltonian for quantum gravity.

We present a nonperturbative quantization of general relativity coupled to dust and other matter fields. The dust provides a natural time variable, leading to a physical Hamiltonian with spatial diffeomorphism symmetry. The surprising feature is that the Hamiltonian is not a square root. This property, together with the kinematical structure of loop quantum gravity, provides a complete theory of quantum gravity, and puts applications to cosmology, quantum gravitational collapse, and Hawking radiation within technical reach. PMID:22540782

Husain, Viqar; Paw?owski, Tomasz

2012-04-01

223

Quantum mechanical tunneling of composite particle systems: Linkage to sub-barrier nuclear reactions

A variety of physical phenomena have at their foundation the quantum tunneling of particles through potential barriers. Many of these phenomena can be associated with the tunneling of single inert particles. The tunneling of composite systems is more complex than for single particles due to the coupling of the tunneling coordinate with the internal degrees of freedom of the tunneling system. Reported here are the results of a study for the tunneling of a two-component projectile incident on a potential energy system which differs for the two components. A specific linkage is made to sub-Coulomb nuclear reactions.

Shotter, A. C. [School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom and TRIUMF, Vancouver (Canada); Shotter, M. D. [Department of Physics, University of Oxford, Oxford (United Kingdom)

2011-05-15

224

Simulating Zeno physics by a quantum quench with superconducting circuits

NASA Astrophysics Data System (ADS)

Studying out-of-equilibrium physics in quantum systems under quantum quench is of vast experimental and theoretical interest. Using periodic quantum quenches, we present an experimentally accessible scheme to simulate the quantum Zeno and anti-Zeno effects in an open quantum system of a single superconducting qubit interacting with an array of transmission line resonators. The scheme is based on the following two observations: First, compared with conventional systems, the short-time nonexponential decay in our superconducting circuit system is readily observed; and second, a quench-off process mimics an ideal projective measurement when its time duration is sufficiently long. Our results show the active role of quantum quench in quantum simulation and control.

Tong, Qing-Jun; An, Jun-Hong; Kwek, L. C.; Luo, Hong-Gang; Oh, C. H.

2014-06-01

225

Unitary quantum physics with time-space noncommutativity

In this work quantum physics in noncommutative spacetime is developed. It is based on the work of Doplicher et al. which allows for time-space noncommutativity. The Moyal plane is treated in detail. In the context of noncommutative quantum mechanics, some important points are explored, such as the formal construction of the theory, symmetries, causality, simultaneity and observables. The dynamics generated

Aiyalam P. Balachandran; Thupil R. Govindarajan; Carlos Molina Mendes; Paulo Teotonio-Sobrinho

2004-01-01

226

Unitary quantum physics with time-space non-commutativity

In these lectures4 quantum physics in noncommutative spacetime is developed. It is based on the work of Doplicher et al. which allows for time-space noncommutativity. In the context of noncommutative quantum mechanics, some important points are explored, such as the formal construction of the theory, symmetries, causality, simultaneity and observables. The dynamics generated by a noncommutative Schrödinger equation is studied.

A. P. Balachandran; T. R. Govindarajan; A. G. Martins; C. Molina; P. Teotonio-Sobrinho

2005-01-01

227

On physical and mathematical causality in quantum mechanics

NASA Astrophysics Data System (ADS)

This paper critically examines the view of quantum phenomena that has persisted since the introduction of quantum mechanics and that still remains prevalent in the foundational literature on quantum theory. According to this view, the independent behavior of quantum systems is causal, while the experimentally manifest lack of causality in observable quantum phenomena and, as a result, the probabilistic nature of our predictions concerning these phenomena are due to the disruption of this causal behavior by interfering with it through the measuring process. It appears that this view originates with P. A. M. Dirac and his work on the transformation theory (introduced by him and P. Jordan), which brought together W. Heisenberg's and E. Schrödinger's versions of quantum mechanics within a single scheme. Other founding figures of quantum theory, specifically N. Bohr, W. Heisenberg, and J. von Neumann, also advanced this view and helped to establish its prominence. The paper discusses these arguments and contends them to be insufficient to support the view that the independent behavior quantum systems is physically causal. It suggests that one can meaningfully speak of mathematical causality in quantum theory, and advocates an alternative, physically noncausal, interpretation of quantum mechanics.

Plotnitsky, Arkady

2010-01-01

228

Quantum corrections to the gravitational interaction of massless particles

NASA Astrophysics Data System (ADS)

Donoghue's effective field theory of quantum gravity is extended to include the interaction of massless particles. The collinear divergences which accompany massless particles are examined first in the context of QED and then in quantum gravity. A result of Weinberg is extended to show how these divergences vanish in the case of gravity. The scattering cross section for hypothetical massless scalar particles is computed first, because it is simpler, and the results are then extended to photons. Some terms in the cross section are shown to correspond to the Aichelburg-Sexl metric surrounding a massless particle and to quantum corrections to that metric. The scattering cross section is also applied to calculate quantum corrections to the bending of starlight, and though small, the result obtained is qualitatively different than in the classical case. Since effective field theory includes the low-energy degrees of freedom which generate collinear divergences, the results presented here will remain relevant in any future quantum theory of gravity.

Blackburn, Thomas J., Jr.

229

Quantum physics: A strong hybrid couple

NASA Astrophysics Data System (ADS)

A single atom in an optical cavity is shown to interact strongly with an incoming photon and to switch the photon's state. This finding opens up a path towards optical quantum computation and quantum networks. See Letters p.237 & p.241

Duan, Luming

2014-04-01

230

Quantum Chaos in Physical Systems: from Super Conductors to Quarks

This article is the written version of a talk delivered at the Bexbach Colloquium of Science 2000 and starts with an introduction into quantum chaos and its relationship to classical chaos. The Bohigas-Giannoni-Schmit conjecture is formulated and evaluated within random-matrix theory. Several examples of physical systems exhibiting quantum chaos ranging from nuclear to solid state physics are presented. The presentation

Elmar Bittner; Harald Markum; Rainer Pullirsch

2001-01-01

231

Impacts of precision CMB measurements on particle physics

NASA Astrophysics Data System (ADS)

We review the impacts of the recent precision cosmic microwave background anisotropy measurements on particle physics. Topics include constraints on the axion, dark radiation, and annihilating dark matter.

Nakayama, Kazunori

2014-06-01

232

Quantum principles and free particles. [evaluation of partitions

NASA Technical Reports Server (NTRS)

The quantum principles that establish the energy levels and degeneracies needed to evaluate the partition functions are explored. The uncertainty principle is associated with the dual wave-particle nature of the model used to describe quantized gas particles. The Schroedinger wave equation is presented as a generalization of Maxwell's wave equation; the former applies to all particles while the Maxwell equation applies to the special case of photon particles. The size of the quantum cell in phase space and the representation of momentum as a space derivative operator follow from the uncertainty principle. A consequence of this is that steady-state problems that are space-time dependent for the classical model become only space dependent for the quantum model and are often easier to solve. The partition function is derived for quantized free particles and, at normal conditions, the result is the same as that given by the classical phase integral. The quantum corrections that occur at very low temperatures or high densities are derived. These corrections for the Einstein-Bose gas qualitatively describe the condensation effects that occur in liquid helium, but are unimportant for most practical purposes otherwise. However, the corrections for the Fermi-Dirac gas are important because they quantitatively describe the behavior of high-density conduction electron gases in metals and explain the zero point energy and low specific heat exhibited in this case.

1976-01-01

233

Particle astronomy and particle physics from the moon - The particle observatory

NASA Technical Reports Server (NTRS)

Promising experiments from the moon using particle detectors are discussed, noting the advantage of the large flux collecting power Pc offered by the remote, stable environment of a lunar base. An observatory class of particle experiments is presented, based upon proposals at NASA's recent Stanford workshop. They vary from neutrino astronomy, particle astrophysics, and cosmic ray experiments to space physics and fundamental physics experiments such as proton decay and 'table-top' arrays. This research is background-limited on earth, and it is awkward and unrealistic in earth orbit, but is particularly suited for the moon where Pc can be quite large and the instrumentation is not subject to atmospheric erosion as it is (for large t) in low earth orbit.

Wilson, Thomas L.

1990-01-01

234

Early history of cosmic particle physics

NASA Astrophysics Data System (ADS)

The discovery of cosmic rays is a standard example of `one man's noise is another man's signal'. From the apparently minor leakages of electricity from well-insulated detectors came a subject of great importance for modern science: the detection of a so-called `radiation' coming from not just beyond the Earth's atmosphere but from deep cosmic space. Furthermore, a radiation of energy density rivalling that of starlight. Our goal is to examine the history of the subject from the period of `pre-discovery' in the years from 1900 to 1912, through the discovery itself up to the 1940's when particle physics was continued with accelerators. The crucial role of `new techniques', principally the Wulf electrometer and the Wilson cloud chamber and their use in precission studies by Hess, Kolhörster, Anderson and Blackett are described. The arguments about the veracity of Hess's claim for an extra-terrestrial origin are included, as well as the developments leading to the inspired discovery of the positron and the muon. The question of `origin' is also examined, from the contention by Hess that the Sun was not responsible, to the idea - still held - that supernovae are involved.

Walter, M.; Wolfendale, A. W.

2012-08-01

235

The International Particle Physics Outreach Group (ippog):. Aims and Activities

NASA Astrophysics Data System (ADS)

The International Particle Physics Outreach Group, IPPOG, is a network of particle physics communication and education experts. IPPOG's principle aim is to maximize the impact of education and outreach efforts related to particle physics through information exchange and the sharing of expertise. IPPOG has initiated several major European and Worldwide activities, such as the "International Particle Physics Masterclasses" where each year thousands of high school students in more than 20 countries come to one of about 120 nearby universities or research centres for a day in order to unravel the mysteries of particle physics. IPPOG has also initiated a global database of education and outreach materials, aimed at supporting other particle physicists and education professionals. The aims and activities of IPPOG will be described, as well as plans to include more countries & laboratories in the network.

Barney, David

2012-08-01

236

Particle hole symmetric Luttinger liquids in a quantum Hall circuit

NASA Astrophysics Data System (ADS)

We report finite-bias differential conductance measurements through a split-gate constriction in the integer quantum Hall regime at ?=1. Both enhanced and suppressed zero-bias inter-edge backscattering can be obtained in a controllable way by changing the split-gate voltage. This behavior is interpreted in terms of local charge depletion and particle-hole symmetry. We discuss the relevance of particle-hole symmetry in connection with the chiral Luttinger model of edge states.

Roddaro, Stefano; Perinetti, Umberto; Pellegrini, Vittorio; Beltram, Fabio; Pfeiffer, Loren N.; West, Ken W.

2006-08-01

237

Refined characterization of student perspectives on quantum physics

NSDL National Science Digital Library

The perspectives of introductory classical physics students can often negatively influence how those students later interpret quantum phenomena when taking an introductory course in modern physics. A detailed exploration of student perspectives on the interpretation of quantum physics is needed, both to characterize student understanding of physics concepts, and to inform how we might teach traditional content. Our previous investigations of student perspectives on quantum physics have indicated they can be highly nuanced, and may vary both within and across contexts. In order to better understand the contextual and often seemingly contradictory stances of students on matters of interpretation, we interviewed 19 students from four introductory modern physics courses taught at the University of Colorado. We find that students have attitudes and opinions that often parallel the stances of expert physicists when arguing for their favored interpretations of quantum mechanics, allowing for more nuanced characterizations of student perspectives in terms of three key interpretive themes. We present a framework for characterizing student perspectives on quantum mechanics, and demonstrate its utility in interpreting the sometimes contradictory nature of student responses to previous surveys. We further find that students most often vacillate in their responses when what makes intuitive sense to them is not in agreement with what they consider to be a correct response, underscoring the need to distinguish between the personal and the public perspectives of introductory modern physics students.

Baily, Charles; Finkelstein, Noah D.

2012-01-20

238

Attention, Intention, and Will in Quantum Physics

The need for a self-observing quantum system to pose questions leads to a\\u000atripartite quantum process involving a Schroedinger process that is local\\u000adeterministic, a Heisenberg process that poses the question, and a Dirac\\u000aprocess that picks the answer. In the classical limit where Planck's constant\\u000ais set to zero these three processes reduce to one single deterministic\\u000aclassical process:

Henry P. Stapp

1999-01-01

239

From classical to quantum mechanics: ``How to translate physical ideas into mathematical language''

NASA Astrophysics Data System (ADS)

Following previous works by E. Prugove?ki [Physica A 91A, 202 (1978) and Stochastic Quantum Mechanics and Quantum Space-time (Reidel, Dordrecht, 1986)] on common features of classical and quantum mechanics, we develop a unified mathematical framework for classical and quantum mechanics (based on L2-spaces over classical phase space), in order to investigate to what extent quantum mechanics can be obtained as a simple modification of classical mechanics (on both logical and analytical levels). To obtain this unified framework, we split quantum theory in two parts: (i) general quantum axiomatics (a system is described by a state in a Hilbert space, observables are self-adjoints operators, and so on) and (ii) quantum mechanics proper that specifies the Hilbert space as L2(Rn); the Heisenberg rule [pi,qj]=-i??ij with p=-i??, the free Hamiltonian H=-?2?/2m and so on. We show that general quantum axiomatics (up to a supplementary ``axiom of classicity'') can be used as a nonstandard mathematical ground to formulate physical ideas and equations of ordinary classical statistical mechanics. So, the question of a ``true quantization'' with ``?'' must be seen as an independent physical problem not directly related with quantum formalism. At this stage, we show that this nonstandard formulation of classical mechanics exhibits a new kind of operation that has no classical counterpart: this operation is related to the ``quantization process,'' and we show why quantization physically depends on group theory (the Galilei group). This analytical procedure of quantization replaces the ``correspondence principle'' (or canonical quantization) and allows us to map classical mechanics into quantum mechanics, giving all operators of quantum dynamics and the Schrödinger equation. The great advantage of this point of view is that quantization is based on concrete physical arguments and not derived from some ``pure algebraic rule'' (we exhibit also some limit of the correspondence principle). Moreover spins for particles are naturally generated, including an approximation of their interaction with magnetic fields. We also recover by this approach the semi-classical formalism developed by E. Prugove?ki [Stochastic Quantum Mechanics and Quantum Space-time (Reidel, Dordrecht, 1986)].

Bergeron, H.

2001-09-01

240

NASA Astrophysics Data System (ADS)

Quantum mechanics is often thought to be a difficult subject to understand, not only in the complexity of its mathematics but also in its conceptual foundation. In this paper we emphasize students’ depictions of the uncertainty principle and wave-particle duality of quantum events, phenomena that could serve as a foundation in building an understanding of quantum mechanics. A phenomenographic study was carried out to categorize a picture of students’ descriptions of these key quantum concepts. Data for this study were obtained from a semistructured in-depth interview conducted with undergraduate physics students (N=25) from Bahir Dar, Ethiopia. The phenomenographic data analysis revealed that it is possible to construct three qualitatively different categories to map students’ depictions of the concept wave-particle duality, namely, (1) classical description, (2) mixed classical-quantum description, and (3) quasiquantum description. Similarly, it is proposed that students’ depictions of the concept uncertainty can be described with four different categories of description, which are (1) uncertainty as an extrinsic property of measurement, (2) uncertainty principle as measurement error or uncertainty, (3) uncertainty as measurement disturbance, and (4) uncertainty as a quantum mechanics uncertainty principle. Overall, we found students are more likely to prefer a classical picture of interpretations of quantum mechanics. However, few students in the quasiquantum category applied typical wave phenomena such as interference and diffraction that cannot be explained within the framework classical physics for depicting the wavelike properties of quantum entities. Despite inhospitable conceptions of the uncertainty principle and wave- and particlelike properties of quantum entities in our investigation, the findings presented in this paper are highly consistent with those reported in previous studies. New findings and some implications for instruction and the curricula are discussed.

Ayene, Mengesha; Kriek, Jeanne; Damtie, Baylie

2011-12-01

241

Quantum physics with non-Hermitian operators Quantum physics with non-Hermitian operators

NASA Astrophysics Data System (ADS)

The main motivation behind the call for this special issue was to gather recent results, developments and open problems in quantum physics with non-Hermitian operators. There have been previous special issues in this journal [1, 2] and elsewhere on this subject. The intention of this issue is to reflect the current state of this rapidly-developing field. It has therefore been open to all contributions containing new results on non-Hermitian theories that are explicitly PT-symmetric and/or pseudo-Hermitian or quasi-Hermitian. In the last decade these types of systems have proved to be viable self-consistent physical theories with well defined unitary time-evolution and real spectra. As the large number of responses demonstrates, this is a rapidly evolving field of research. A consensus has been reached regarding most of the fundamental problems, and the general ideas and techniques are now readily being employed in many areas of physics. Nonetheless, this issue still contains some treatments of a more general nature regarding the spectral analysis of these models, in particular, the physics of the exceptional points, the breaking of the PT-symmetry, an interpretation of negative energies and the consistent implementation of the WKB analysis. This issue also contains a treatment of a scattering theory associated with these types of systems, weak measurements, coherent states, decoherence, unbounded metric operators and the inclusion of domain issues to obtain well defined self-adjoint theories. Contributions in the form of applications of the general ideas include: studies of classical shock-waves and tunnelling, supersymmetric models, spin chain models, models with ring structure, random matrix models, the Pauli equation, the nonlinear Schrödinger equation, quasi-exactly solvable models, integrable models such as the Calogero model, Bose-Einstein condensates, thermodynamics, nonlinear oligomers, quantum catastrophes, the Landau-Zener problem and pseudo-Fermions. Applications close to experimental realization are proposed in optics, including short light pulse models, waveguides and laser systems, and also in electronics. We hope that this issue will become a valuable reference and inspiration for the broader scientific community working in mathematical and theoretical physics. References [1] Fring A, Jones H F and Znojil M (ed) 2008 J. Phys. A: Math. Theor. 41 240301 [2] Geyer H, Heiss D and Znojil M (ed) 2006 J. Phys. A: Math. Gen. 39 9963

Bender, Carl; Fring, Andreas; Günther, Uwe; Jones, Hugh

2012-11-01

242

Relativistic-Particle Quantum Mechanics (Applications and Approximations) II.

National Technical Information Service (NTIS)

In this lecture I hope to show that relativistic-particle quantum mechanics with direct interactions is a useful tool for building models applicable to hadron systems at intermediate energies. To do this I will first describe a class of models designed to...

F. Coester

1981-01-01

243

Screening of particle exchange in quantum Boltzmann liquids

We employ correlated density-matrix theory of strongly correlated Bose fluids to analyze the structural properties of quantum Boltzmann liquids. The constituents of such a normal quantum system are distinguishable as in a classical fluid since the interparticle forces prevent any exchange of identical bosons at short relative distances. Our study focuses on this particle-screening effect and on its consequences for the properties of various correlation functions, structure functions, momentum distributions, and quasiparticle and collective excitations. The formalism of the adopted microscopic theory is applied to a detailed numerical investigation of particle-screening properties and the quantum behavior of liquid para-hydrogen close to the triple point temperature. The theoretical results are compared with numerical data of path-integral Monte Carlo simulations and with available experimental results of recent cross-section measurements by neutron scattering.

Gernoth, K. A. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Lindenau, T.; Ristig, M. L. [Institut fuer Theoretische Physik, Universitaet zu Koeln, D-50937 Cologne (Germany)

2007-05-01

244

Quantum maximum entropy principle for a system of identical particles

By introducing a functional of the reduced density matrix, we generalize the definition of a quantum entropy which incorporates the indistinguishability principle of a system of identical particles. With the present definition, the principle of quantum maximum entropy permits us to solve the closure problem for a quantum hydrodynamic set of balance equations corresponding to an arbitrary number of moments in the framework of extended thermodynamics. The determination of the reduced Wigner function for equilibrium and nonequilibrium conditions is found to become possible only by assuming that the Lagrange multipliers can be expanded in powers of (Planck constant/2pi){sup 2}. Quantum contributions are expressed in powers of (Planck constant/2pi){sup 2} while classical results are recovered in the limit (Planck constant/2pi)->0.

Trovato, M. [Dipartimento di Matematica, Universita di Catania, Viale A. Doria, 95125 Catania (Italy); Reggiani, L. [Dipartimento di Ingegneria dell' Innovazione and CNISM, Universita del Salento, Via Arnesano s/n, 73100 Lecce (Italy)

2010-02-15

245

The future of particle physics in outer space

Particle physics started as the study of cosmic rays. After having settled on the ground for half a century, it is about to conquer the outer space with satellite and space shuttle borne instruments. Particle physics has actually strong connections with astrophysics and cosmology. This contribution deals with a few of these ties. The exploration of the gamma ray sky

P. Salati

1998-01-01

246

Alpha Particle Physics Experiments in the Tokamak Fusion Test Reactor

Alpha particle physics experiments were done on the Tokamak Fusion Test Reactor (TFTR) during its deuterium-tritium (DT) run from 1993-1997. These experiments utilized several new alpha particle diagnostics and hundreds of DT discharges to characterize the alpha particle confinement and wave-particle interactions. In general, the results from the alpha particle diagnostics agreed with the classical single-particle confinement model in magnetohydrodynamic (MHD) quiescent discharges. Also, the observed alpha particle interactions with sawteeth, toroidal Alfvén eigenmodes (TAE), and ion cyclotron resonant frequency (ICRF) waves were roughly consistent with theoretical modeling. This paper reviews what was learned and identifies what remains to be understood.

Budny, R.V.; Darrow, D.S.; Medley, S.S.; Nazikian, R.; Zweben, S.J.; et al.

1998-12-14

247

Open Source Physics Curricular Material for Quantum Mechanics

NSDL National Science Digital Library

The Open Source Physics Curricular Material paper describes the interactive curricular material created as part of the Open Source Physics project for the teaching and learning of quantum mechanics. Here we focus on the measurement and time evolution of two-state superpositions in the context of bound states and spin.

Belloni, Mario; Christian, Wolfgang; Brown, Douglas

2008-05-30

248

Making the Transition from Classical to Quantum Physics

ERIC Educational Resources Information Center

This paper reports on the nature of the conceptual understandings developed by Year 12 Victorian Certificate of Education (VCE) physics students as they made the transition from the essentially deterministic notions of classical physics, to interpretations characteristic of quantum theory. The research findings revealed the fact that the…

Dutt, Amit

2011-01-01

249

Pre-Service Physics Teachers' Comprehension of Quantum Mechanical Concepts

ERIC Educational Resources Information Center

When quantum theory caused a paradigm shift in physics, it introduced difficulties in both learning and teaching of physics. Because of its abstract, counter-intuitive and mathematical structure, students have difficulty in learning this theory, and instructors have difficulty in teaching the concepts of the theory. This case study investigates…

Didis, Nilufer; Eryilmaz, Ali; Erkoc, Sakir

2010-01-01

250

International Summer Institute in Quantum Chemistry, Solid State Physics and Quantum Biology.

National Technical Information Service (NTIS)

The International Summer Institute in Quantum Chemistry, Solid State Physics and Quantum Biology was held in two parts: from 1-12 Aug 1967 at the Univ. of Uppsala, Sweden, and from 14 Aug - 2 Sep 1967 at Sjusjoen, Norway. This report describes only the se...

M. Weissbluth

1967-01-01

251

Two decades of Mexican particle physics at Fermilab

This report is a view from Fermilab of Mexican particle physics at the Laboratory since about 1980; it is not intended to be a history of Mexican particle physics: that topic is outside the expertise of the writer. The period 1980 to the present coincides with the growth of Mexican experimental particle physics from essentially no activity to its current state where Mexican groups take part in experiments at several of the world's major laboratories. Soon after becoming Fermilab director in 1979, Leon Lederman initiated a program to encourage experimental physics, especially experimental particle physics, in Latin America. At the time, Mexico had significant theoretical particle physics activity, but none in experiment. Following a visit by Lederman to UNAM in 1981, a conference ''Panamerican Symposium on Particle Physics and Technology'' was held in January 1982 at Cocoyoc, Mexico, with about 50 attendees from Europe, North America, and Latin America; these included Lederman, M. Moshinsky, J. Flores, S. Glashow, J. Bjorken, and G. Charpak. Among the conference outcomes were four subsequent similar symposia over the next decade, and a formal Fermilab program to aid Latin American physics (particularly particle physics); it also influenced a decision by Mexican physicist Clicerio Avilez to switch from theoretical to experimental particle physics. The first physics collaboration between Fermilab and Mexico was in particle theory. Post-docs Rodrigo Huerta and Jose Luis Lucio spent 1-2 years at Fermilab starting in 1981, and other theorists (including Augusto Garcia, Arnulfo Zepeda, Matias Moreno and Miguel Angel Perez) also spent time at the Laboratory in the 1980s.

Roy Rubinstein

2002-12-03

252

Annihilation physics of exotic galactic dark matter particles

NASA Technical Reports Server (NTRS)

Various theoretical arguments make exotic heavy neutral weakly interacting fermions, particularly those predicted by supersymmetry theory, attractive candidates for making up the large amount of unseen gravitating mass in galactic halos. Such particles can annihilate with each other, producing secondary particles of cosmic-ray energies, among which are antiprotons, positrons, neutrinos, and gamma-rays. Spectra and fluxes of these annihilation products can be calculated, partly by making use of positron electron collider data and quantum chromodynamic models of particle production derived therefrom. These spectra may provide detectable signatures of exotic particle remnants of the big bang.

Stecker, F. W.

1990-01-01

253

Quantum physics of simple optical instruments

Simple optical instruments are linear optical networks where the incident light modes are turned into equal numbers of outgoing modes by linear transformations. For example, such instruments are beam splitters, multiports, interferometers, fibre couplers, polarizers, gravitational lenses, parametric amplifiers, phase-conjugating mirrors and also black holes. The paper develops the quantum theory of simple optical instruments and applies the theory to

Ulf Leonhardt

2003-01-01

254

Heim Quantum Theory for Space Propulsion Physics

This paper describes a novel space propulsion technique, based on an extension of a unified field theory in a quantized, higher-dimensional space, developed by the late B. Heim (1977) in the 50s and 60s of the last century, termed Heim Quantum Theory (HQT). As a consequence of the unification, HQT predicts six fundamental interactions. The two additional interactions should enable

Walter Dröscher; Jochem Häuser

2005-01-01

255

Generation of quantum logic operations from physical Hamiltonians

We provide a systematic analysis of the physical generation of single- and two-qubit quantum operations from Hamiltonians available in various quantum systems for scalable quantum information processing. We show that generation of single-qubit operations can be transformed into a steering problem on the Bloch sphere, which represents all R{sub z}-equivalence classes of single-qubit operations, whereas the two-qubit problem can be generally transformed into a steering problem in a tetrahedron representing all the local-equivalence classes of two-qubit operations (the Weyl chamber). We use this approach to investigate several physical examples for the generation of two-qubit operations. The steering approach provides useful guidance for the realization of various quantum computation schemes.

Zhang Jun [Department of Chemistry and Pitzer Center for Theoretical Chemistry, University of California, Berkeley, California 94720 (United States); Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Whaley, K. Birgitta [Department of Chemistry and Pitzer Center for Theoretical Chemistry, University of California, Berkeley, California 94720 (United States)

2005-05-15

256

Elementary particle physics from general relativity

This paper presents a qualitative comparison of opposing views of elementary matter—the Copenhagen approach in quantum mechanics and the theory of general relativity. It discusses in detail some of their main conceptual differences, when each theory is fully exploited as a theory of matter, and it indicates why each of these theories, at its presently accepted state, is incomplete without

Mendel Sachs

1981-01-01

257

Quantum Hall physics with photons and its application

NASA Astrophysics Data System (ADS)

Phenomena associated with the topological properties of physical systems can be naturally robust against perturbations. This robustness is exemplified by quantized conductance and edge state transport in the quantum Hall and quantum spin Hall effects. Here we demonstrate how quantum spin Hall Hamiltonians can be simulated with linear optical elements using a network of coupled resonator optical waveguides (CROW) in two dimensions. Key features of quantum Hall systems, including the characteristic Hofstadter butterfly and robust edge state transport, can be obtained in such systems. As a specific application, we show that topological protection can be used to improve the performance of optical delay lines and to overcome some limitations related to disorder in photonic technologies. Furthermore, the addition of an optical non-linearity to our proposed system leads to the possibility of implementing a fractional quantum Hall state of photons, where phenomenon such as fractional statistics may be observable.

Hafezi, Mohammad

2012-02-01

258

Quantum Physics made Relatively Simple: Three Lectures by Hans Bethe

NSDL National Science Digital Library

The site contains three lectures of Professor Hans Bethe. The lecture topics concern the development of quantum theory; relations between the exciting theoretical/experimental breakthrough; and how quantum theory forced discussion of issues such as determinism, physical observables, and action-at-a-distance. Professor Hans delivered these three lectures in 1999 to his neighbors at the Kendal of Ithaca retirement community (near Cornell University in Ithaca, NY).

Bethe, Hans

2006-07-22

259

Tau Leton and the Search for New Elementary Particle Physics.

National Technical Information Service (NTIS)

This Fifth International WEIN Symposium is devoted to physics beyond the standard model. This talk is about tau lepton physics, but I begin with the question: do we know how to find new physics in the world of elementary particles. This question is interw...

M. L. Perl

1998-01-01

260

Particle Physics Meets Cosmology -- The Search for Decaying Neutrinos.

ERIC Educational Resources Information Center

Detection of neutrino decay may have profound consequences for both particle physics and cosmology, providing a deep connection between physics of the very large and physics of the very small. Describes this link and discusses the nature and status of the search for decaying neutrinos. (Author/JN)

Henry, Richard C.

1982-01-01

261

Challenging the weak cosmic censorship conjecture with charged quantum particles

NASA Astrophysics Data System (ADS)

Motivated by the recent attempts to violate the weak cosmic censorship conjecture for near-extreme black holes, we consider the possibility of overcharging a near-extreme Reissner-Nordström black hole by the quantum tunneling of charged particles. We consider the scattering of spin-0 and spin-(1)/(2) particles by the black hole in a unified framework and obtain analytically, for the first time, the pertinent reflection and transmission coefficients without any small charge approximation. Based on these results, we propose some gedanken experiments that could lead to the violation of the weak cosmic censorship conjecture due to the (classically forbidden) absorption of small energy charged particles by the black hole. As for the case of scattering in Kerr spacetimes, our results demonstrate explicitly that scalar fields are subject to (electrical) superradiance phenomenon, while spin-(1)/(2) fields are not. Superradiance impose some limitations on the gedanken experiments involving spin-0 fields, favoring, in this way, the mechanisms for creation of a naked singularity by the quantum tunneling of spin-(1)/(2) charged fermions. We also discuss the implications that vacuum polarization effects and quantum statistics might have on these gedanken experiments. In particular, we show that they are not enough to prevent the absorption of incident small energy particles and, consequently, the formation of a naked singularity.

Richartz, Maurício; Saa, Alberto

2011-11-01

262

Quantum particle on a Möbius strip, coherent states and projection operators

NASA Astrophysics Data System (ADS)

The coherent states for a quantum particle on a Möbius strip are constructed and their relation to the natural phase space for fermionic fields is shown. The explicit comparison of the obtained states with previous works where the cylinder quantization was used and the spin-1/2 was introduced by hand is given, and the relation between the geometrical phase space, constraints and projection operators is analyzed and discussed. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Coherent states: mathematical and physical aspects’.

Julio Cirilo-Lombardo, Diego

2012-06-01

263

Families of Particles with Different Masses in PT-Symmetric Quantum Field Theory

An elementary field-theoretic mechanism is proposed that allows one Lagrangian to describe a family of particles having different masses but otherwise similar physical properties. The mechanism relies on the observation that the Dyson-Schwinger equations derived from a Lagrangian can have many different but equally valid solutions. Nonunique solutions to the Dyson-Schwinger equations arise when the functional integral for the Green's functions of the quantum field theory converges in different pairs of Stokes' wedges in complex-field space, and the solutions are physically viable if the pairs of Stokes' wedges are PT symmetric.

Bender, Carl M. [Physics Department, Washington University, St. Louis, Missouri 63130 (United States); Klevansky, S. P. [Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 19, 69120 Heidelberg (Germany)

2010-07-16

264

A Reconfigurable Instrument System for Nuclear and Particle Physics Experiments

NASA Astrophysics Data System (ADS)

We developed a reconfigurable nuclear instrument system (RNIS) that could satisfy the requirements of diverse nuclear and particle physics experiments, and the inertial confinement fusion diagnostic. Benefiting from the reconfigurable hardware structure and digital pulse processing technology, RNIS shakes off the restrictions of cumbersome crates and miscellaneous modules. It retains all the advantages of conventional nuclear instruments and is more flexible and portable. RNIS is primarily composed of a field programmable hardware board and relevant PC software. Separate analog channels are designed to provide different functions, such as amplifiers, ADC, fast discriminators and Schmitt discriminators for diverse experimental purposes. The high-performance field programmable gate array could complete high-precision time interval measurement, histogram accumulation, counting, and coincidence anticoincidence measurement. To illustrate the prospects of RNIS, a series of applications to the experiments are described in this paper. The first, for which RNIS was originally developed, involves nuclear energy spectrum measurement with a scintillation detector and photomultiplier. The second experiment applies RNIS to a G-M tube counting experiment, and in the third, it is applied to a quantum communication experiment through reconfiguration.

Sang, Ziru; Li, Feng; Jiang, Xiao; Jin, Ge

2014-04-01

265

Particle physics meets cosmology - The search for decaying neutrinos

NASA Technical Reports Server (NTRS)

The fundamental physical implications of the possible detection of massive neutrinos are discussed, with an emphasis on the Grand Unified Theories (GUTs) of matter. The Newtonian and general-relativistic pictures of the fundamental forces are compared, and the reduction of electromagnetic and weak forces to one force in the GUTs is explained. The cosmological consequences of the curved-spacetime gravitation concept are considered. Quarks, leptons, and neutrinos are characterized in a general treatment of elementary quantum mechanics. The universe is described in terms of quantized fields, the noninteractive 'particle' fields and the force fields, and cosmology becomes the study of the interaction of gravitation with the other fields, of the 'freezing out' of successive fields with the expansion and cooling of the universe. While the visible universe is the result of the clustering of the quark and electron fields, the distribution of the large number of quanta in neutrino field, like the mass of the neutrino, are unknown. Cosmological models which attribute anomalies in the observed motions of galaxies and stars to clusters or shells of massive neutrinos are shown to be consistent with a small but nonzero neutrino mass and a universe near the open/closed transition point, but direct detection of the presence of massive neutrinos by the UV emission of their decay is required to verify these hypotheses.

Henry, R. C.

1982-01-01

266

Quantum Hall Physics Equals Noncommutative Field Theory

In this note, we study a matrix-regularized version of non-commutative U(1) Chern- Simons theory proposed recently by Polychronakos. We determine a complete minimal basis of exact wavefunctions for the theory at arbitrary level k and rank N and show that these are in one-to-one correspondence with Laughlin-type wavefunctions describing excitations of a quantum Hall droplet composed of N electrons at

Simeon Hellerman; Mark Van Raamsdonk

267

Relativistic models in nuclear and particle physics

A comparative overview is presented of different approaches to the construction of phenomenological dynamical models that respect basic principles of quantum theory and relativity. Wave functions defined as matrix elements of products of field operators on one hand and wave functions that are defined as representatives of state vectors in model Hilbert spaces are related differently to observables and dynamical models for these wave functions have each distinct advantages and disadvantages 34 refs.

Coester, F.

1988-01-01

268

Nuclear spin physics in quantum dots: An optical investigation

NASA Astrophysics Data System (ADS)

The mesoscopic spin system formed by the 104-106 nuclear spins in a semiconductor quantum dot offers a unique setting for the study of many-body spin physics in the condensed matter. The dynamics of this system and its coupling to electron spins is fundamentally different from its bulk counterpart or the case of individual atoms due to increased fluctuations that result from reduced dimensions. In recent years, the interest in studying quantum-dot nuclear spin systems and their coupling to confined electron spins has been further fueled by its importance for possible quantum information processing applications. The fascinating nonlinear (quantum) dynamics of the coupled electron-nuclear spin system is universal in quantum dot optics and transport. In this article, experimental work performed over the last decade in studying this mesoscopic, coupled electron-nuclear spin system is reviewed. Here a special focus is on how optical addressing of electron spins can be exploited to manipulate and read out the quantum-dot nuclei. Particularly exciting recent developments in applying optical techniques to efficiently establish nonzero mean nuclear spin polarizations and using them to reduce intrinsic nuclear spin fluctuations are discussed. Both results critically influence the preservation of electron-spin coherence in quantum dots. This overall recently gained understanding of the quantum-dot nuclear spin system could enable exciting new research avenues such as experimental observations of spontaneous spin ordering or nonclassical behavior of the nuclear spin bath.

Urbaszek, Bernhard; Marie, Xavier; Amand, Thierry; Krebs, Olivier; Voisin, Paul; Maletinsky, Patrick; Högele, Alexander; Imamoglu, Atac

2013-01-01

269

New phenomena in non-equilibrium quantum physics

NASA Astrophysics Data System (ADS)

From its beginning in the early 20th century, quantum theory has become progressively more important especially due to its contributions to the development of technologies. Quantum mechanics is crucial for current technology such as semiconductors, and also holds promise for future technologies such as superconductors and quantum computing. Despite of the success of quantum theory, its applications have been mostly limited to equilibrium or static systems due to 1. lack of experimental controllability of non-equilibrium quantum systems 2. lack of theoretical frameworks to understand non-equilibrium dynamics. Consequently, physicists have not yet discovered too many interesting phenomena in non-equilibrium quantum systems from both theoretical and experimental point of view and thus, non-equilibrium quantum physics did not attract too much attentions. The situation has recently changed due to the rapid development of experimental techniques in condensed matter as well as cold atom systems, which now enables a better control of non-equilibrium quantum systems. Motivated by this experimental progress, we constructed theoretical frameworks to study three different non-equilibrium regimes of transient dynamics, steady states and periodically drives. These frameworks provide new perspectives for dynamical quantum process, and help to discover new phenomena in these systems. In this thesis, we describe these frameworks through explicit examples and demonstrate their versatility. Some of these theoretical proposals have been realized in experiments, confirming the applicability of the theories to realistic experimental situations. These studies have led to not only the improved fundamental understanding of non-equilibrium processes in quantum systems, but also suggested entirely different venues for developing quantum technologies.

Kitagawa, Takuya

270

Shock Physics Simulation Using a Hybrid Particle-Element Method

NASA Astrophysics Data System (ADS)

Some important shock physics applications have motivated the development of numerical methods based on mixed particle-finite element formulations. Although pure continuum and pure particle based methods are well suited for use in many shock physics problems, their underlying kinematic schemes limit their utility in selected applications. An example is hypervelocity impact simulation, which requires both accurate modeling of strength effects and general descriptions of contact-impact dynamics for all structures and material fragments. In recent research the hybrid particle-element method of References [1] and [2] has been validated and applied in simulations of one and three dimensional shock physics problems.

Fahrenthold, Eric P.

2006-07-01

271

Particle entanglement in continuum many-body systems via quantum Monte Carlo

NASA Astrophysics Data System (ADS)

Entanglement of spatial bipartitions, used to explore lattice models in condensed matter physics, may be insufficient to fully describe itinerant quantum many-body systems in the continuum. We introduce a procedure to measure the Rényi entanglement entropies on a particle bipartition, with general applicability to continuum Hamiltonians via path integral Monte Carlo methods. Via direct simulations of interacting bosons in one spatial dimension, we confirm a logarithmic scaling of the single-particle entanglement entropy with the number of particles in the system. The coefficient of this logarithmic scaling increases with interaction strength, saturating to unity in the strongly interacting limit. Additionally, we show that the single-particle entanglement entropy is bounded by the condensate fraction, suggesting a practical route towards its measurement in future experiments.

Herdman, C. M.; Roy, P.-N.; Melko, R. G.; Del Maestro, A.

2014-04-01

272

Free-Dirac-particle evolution as a quantum random walk

NASA Astrophysics Data System (ADS)

It is known that any positive-energy state of a free Dirac particle that is initially highly localized evolves in time by spreading at speeds close to the speed of light. As recently indicated by Strauch, this general phenomenon, and the resulting “two-horned” distributions of position probability along any axis through the point of initial localization, can be interpreted in terms of a quantum random walk, in which the roles of “coin” and “walker” are naturally associated with the spin and translational degrees of freedom in a discretized version of Dirac’s equation. We investigate the relationship between these two evolutions analytically and show how the evolved probability density on the x axis for the Dirac particle at any time t can be obtained from the asymptotic form of the probability distribution for the position of a “quantum walker.” The case of a highly localized initial state is discussed as an example.

Bracken, A. J.; Ellinas, D.; Smyrnakis, I.

2007-02-01

273

NASA Astrophysics Data System (ADS)

We first study the edge transport in the ?=1/3 and ?=2/3 Fractional Quantum Hall bars mediated by a ?=1 quantum dot. We conclude that the ?=1/3 and ?=2/3 systems show different 1/3-charged quasi-particle tunneling exponents. When the quantum dot becomes large, its edge states join those of the original Hall bar to reconstruct the edge state configurations. In the disorder-irrelevant phase, the two-terminal conductance of the original ?=1/3 system vanishes at zero temperature, while that of the ?=2/3 case is finite. In the disorder-dominated phase, the two-terminal conductance of ?=1/3 system is (1/5)e^2/h while that of ?=2/3 system is (1/2)e^2/h. We further apply the same idea to the ?=5/2 system which realizes either Pfaffian or anti-Pfaffian states. By engineering a central ?=3 quantum dot in the ?=5/2 Hall bar, we study the charged quasi-particle tunneling effects and conclude that the Pfaffian and anti-Pfaffian states show different quasi-particle tunneling exponents. If the quantum dot is large enough for its edge states joining with those of the original Hall bar, the two-terminal conductance of Pfaffian state can be GPf->2 e^2/h while that of anti-Pfaffian state is higher, GaPf> 2 e^2/h.

Lai, Hsin-Hua; Yang, Kun

2013-03-01

274

Finite quantum physics and noncommutative geometry.

National Technical Information Service (NTIS)

Conventional discrete approximations of a manifold do not preserve its nontrivial topological features. In this article we describe an approximation scheme due to Sorkin which reproduces physically important aspects of manifold topology with striking fide...

A. P. Balachandran E. Ercolessi G. Landi P. Teotonio-Sobrinho G. Bimonte

1994-01-01

275

Computational physics: A quantum puzzle revisited

Computational condensed-matter physics acquires a novel compass in the search for unknown stable structures. This global phase-space search algorithm demonstrates its power in solving the complex high-pressure phases of hydrogen.

Tadashi Ogitsu

2007-01-01

276

Lyapunov control of a quantum particle in a decaying potential

A Lyapunov-based approach for the trajectory generation of an N-dimensional Schrödinger equation in whole RN is proposed. For the case of a quantum particle in an N-dimensional decaying potential the convergence is precisely analyzed. The free system admitting a mixed spectrum, the dispersion through the absolutely continuous part is the main obstacle to ensure such a stabilization result. Whenever, the

Mazyar Mirrahimi

2009-01-01

277

The geometric phase in quantum physics

After an explanatory introduction, a quantum system in a classical time-dependent environment is discussed; an example is a magnetic moment in a classical magnetic field. At first, the general abelian case is discussed in the adiabatic approximation. Then the geometric phase for nonadiabatic change of the environment (Anandan--Aharonov phase) is introduced, and after that general cyclic (nonadiabatic) evolution is discussed. The mathematics of fiber bundles is introduced, and some of its results are used to describe the relation between the adiabatic Berry phase and the geometric phase for general cyclic evolution of a pure state. The discussion is restricted to the abelian, U(1) phase.

Bohm, A.

1993-03-01

278

Research in high energy elementary particle physics

This is a progress report covering the period March 1, 1986 through February 29, 1988 for the High Energy Physics program at the University of Florida (DOE Florida Demonstration Project grant FG05-86-ER40272). The research program covers a broad range of topics in theoretical and experimental physics and includes detector development and an Axion search. Included in this report is a

R. Field; P. Ramond; C. Thorn; P. Avery; J. Walker; D. Tanner; P. Sikivie; N. Sullivan; S. Majeswki

1988-01-01

279

The role of supersymmetry phenomenology in particle physics

Supersymmetry phenomenology is an important component of particle physics today. I provide a definition of supersymmetry phenomenology, outline the scope of its activity, and argue its legitimacy. This essay derives from a presentation given at the 2000 SLAC Summer Institute.

Wells, James D.

2000-12-14

280

Astro particle physics with AMS on the International Space Station

We review how AMS will study open issues on astro particle physics operating for three years on the International Space Station, complementary to searches done at underground and accelerator facilities.

R. Battiston

2003-01-01

281

Knowledge Transfer of Microstrip Detectors: From Particle to Medical Physics.

National Technical Information Service (NTIS)

This project is a demonstration of Knowledge Transfer. Knowledge in the fabrication, operation and application of radiation detectors originally developed for particle physics experiments has been exploited in diverse areas of research like medical applic...

S. Manolopoulos

2007-01-01

282

Quarks and Leptones: An Introductory Course in Modern Particle Physics

This self-contained text describes breakthroughs in our understanding of the structure and interactions of elementary particles. It provides students of theoretical or experimental physics with the background material to grasp the significance of these developments.

Francis Halzen; Alan D. Martin

1984-01-01

283

Mapping of topological quantum circuits to physical hardware.

Topological quantum computation is a promising technique to achieve large-scale, error-corrected computation. Quantum hardware is used to create a large, 3-dimensional lattice of entangled qubits while performing computation requires strategic measurement in accordance with a topological circuit specification. The specification is a geometric structure that defines encoded information and fault-tolerant operations. The compilation of a topological circuit is one important aspect of programming a quantum computer, another is the mapping of the topological circuit into the operations performed by the hardware. Each qubit has to be controlled, and measurement results are needed to propagate encoded quantum information from input to output. In this work, we introduce an algorithm for mapping an topological circuit to the operations needed by the physical hardware. We determine the control commands for each qubit in the computer and the relevant measurements that are needed to track information as it moves through the circuit. PMID:24722360

Paler, Alexandru; Devitt, Simon J; Nemoto, Kae; Polian, Ilia

2014-01-01

284

Mapping of Topological Quantum Circuits to Physical Hardware

NASA Astrophysics Data System (ADS)

Topological quantum computation is a promising technique to achieve large-scale, error-corrected computation. Quantum hardware is used to create a large, 3-dimensional lattice of entangled qubits while performing computation requires strategic measurement in accordance with a topological circuit specification. The specification is a geometric structure that defines encoded information and fault-tolerant operations. The compilation of a topological circuit is one important aspect of programming a quantum computer, another is the mapping of the topological circuit into the operations performed by the hardware. Each qubit has to be controlled, and measurement results are needed to propagate encoded quantum information from input to output. In this work, we introduce an algorithm for mapping an topological circuit to the operations needed by the physical hardware. We determine the control commands for each qubit in the computer and the relevant measurements that are needed to track information as it moves through the circuit.

Paler, Alexandru; Devitt, Simon J.; Nemoto, Kae; Polian, Ilia

2014-04-01

285

(Physics and chemistry of van der Waals particles)

Accounts are given of the two major international conferences on the physics and chemistry of small particles, commonly referred to as van der Waals particles. Details of special interest to Oak Ridge National Laboratory personnel are cited. Information exchanges at Freiburg and Paris are described.

Klots, C.E.

1990-10-08

286

Quarks, Leptons, and Bosons: A Particle Physics Primer.

ERIC Educational Resources Information Center

Presented is a non-technical introduction to particle physics. The material is adapted from chapter 3 of "Cosmic Horizons," (by Robert Wagoner and Don Goldsmith), a lay-person's introduction to cosmology. Among the topics considered are elementary particles, forces and motion, and higher level structures. (JN)

Wagoner, Robert; Goldsmith, Donald

1983-01-01

287

Teaching Particle Physics in the Open University's Science Foundation Course.

ERIC Educational Resources Information Center

Discusses four topics presented in the science foundation course of the Open University that exemplify current developments in particle physics, in particular, and that describe important issues about the nature of science, in general. Topics include the omega minus particle, the diversity of quarks, the heavy lepton, and the discovery of the W…

Farmelo, Graham

1992-01-01

288

ERIC Educational Resources Information Center

Explains the critical role of probability in making sense of quantum physics and addresses the difficulties science and engineering undergraduates experience in helping students build a model of how to think about probability in physical systems. (Contains 17 references.) (Author/YDS)

Bao, Lei; Redish, Edward F.

2002-01-01

289

Probability plays a critical role in making sense of quantum physics, but most science and engineering undergraduates have very little experience with the topic. A probabilistic interpretation of a physical system, even at a classical level, is often completely new to them, and the relevant fundamental concepts such as the probability distribution and probability density are rarely understood. To address

Lei Bao; Edward F. Redish

2002-01-01

290

Quantum Physics and Mental Health Counseling: The Time Is...!

ERIC Educational Resources Information Center

Introduces a new framework of mental health counseling based on quantum physics. The framework stresses systemic thinking and intervention, interdependence, and the importance of adopting a novel perspective about time, space, reality, and change. This framework has the potential of modifying mental health counseling practice and training. Offers…

Gerstein, Lawrence H.; Bennett, Matt

1999-01-01

291

Finite element approximations of nonlinear eigenvalue problems in quantum physics

In this paper, we study finite element approximations of a class of nonlinear eigenvalue problems arising from quantum physics. We derive both a priori and a posteriori finite element error estimates and obtain optimal convergence rates for both linear and quadratic finite element approximations. In particular, we analyze the convergence and complexity of an adaptive finite element method. In our

Huajie Chen; Lianhua He; Aihui Zhou

2011-01-01

292

Elementary Particle Physics at Baylor (Final Report)

This report summarizes the activities of the Baylor University Experimental High Energy Physics (HEP) group on the Collider Detector at Fermilab (CDF) experiment from August 15, 2005 to May 31, 2012. Led by the Principal Investigator (Dr. Jay R. Dittmann), the Baylor HEP group has actively pursued a variety of cutting-edge measurements from proton-antiproton collisions at the energy frontier.

Dittmann, J.R.

2012-08-25

293

The quantum physics of chronology protection

This is a brief survey of the current status of Stephen Hawking's\\u000a``chronology protection conjecture''. That is: ``Why does nature abhor a time\\u000amachine?'' I'll discuss a few examples of spacetimes containing ``time\\u000amachines'' (closed causal curves), the sorts of peculiarities that arise, and\\u000athe reactions of the physics community. While pointing out other possibilities,\\u000athis article concentrates on the

Matt Visser

2002-01-01

294

Phase transitions and elementary-particle physics

The reason physicists have recently taken an intense interest in the statistical mechanics of certain lattice models is reviewed. Phase transitions in these systems are of direct relevance to whether the gauge theory of interacting quarks and gluons can prevent the quark as appearing as a free isolated object. Monte Carlo simulation techniques have given the strongest evidence for the confinement phenomenon and are beginning to make numerical predictions in strong interaction physics.

Creutz, M.

1981-01-01

295

A Geometrical Model for the Elementary Particles of Physics

NASA Astrophysics Data System (ADS)

Geometrical objects with certain topological properties are investigated in order to construct a visualizable model of the fundamental particles and processes of physics. The treatment is primarily conceptual and phenomenological with a set of diagrams portraying the objects of interest. A taxonomy of objects and diagrams is developed, various symmetries are identified, and corespondences are established to known physical constraints and invariances. A number of the principal tenets of particle physics appear to have a geometrical basis and a novel, unified way of regarding elementary particles and interactions emerges. The model is used to compute the ratio of the neutron's magnetic moment to that of the proton. Some interactions and decay processes are also modeled. Finally, the model is used in a geometrical approach to develop a particle family structure and explain its restriction to three generations.

Avrin, J. S.

1998-10-01

296

J-PARC Status, Nuclear and Particle Physics

J-PARC accelerator research complex, consisting of LINAC, RCS and MR synchrotron, has successfully produced neutron, muons, kaons, and neutrinos by steady commissioning since November 2006. There are three experimental facilities, and for nuclear and particle physics, nine experiments are approved in a hadron physics facility, and one experiment is approved in a neutrino physics facility. Those experiments and status of J-PARC are described in this paper.

Sato, Susumu [Advanced Science Research Center/J-PARC Center, Japan Atomic Energy Agency, Shirakata-shirane 2-4, Tokai, Ibaraki, 319-1195 (Japan)

2011-06-01

297

Black hole bombs and explosions: from astrophysics to particle physics

NASA Astrophysics Data System (ADS)

Black holes are the elementary particles of gravity, the final state of sufficiently massive stars and of energetic collisions. With a 40-year long history, black hole physics is a fully-blossomed field which promises to embrace several branches of theoretical physics. Here I review the main developments in highly dynamical black holes with an emphasis on high energy black hole collisions and probes of particle physics via superradiance. This write-up, rather than being a collection of well known results, is intended to highlight open issues and the most intriguing results.

Cardoso, Vitor

2013-11-01

298

Octonions, E6, and particle physics

NASA Astrophysics Data System (ADS)

In 1934, Jordan et al. gave a necessary algebraic condition, the Jordan identity, for a sensible theory of quantum mechanics. All but one of the algebras that satisfy this condition can be described by Hermitian matrices over the complexes or quaternions. The remaining, exceptional Jordan algebra can be described by 3 × 3 Hermitian matrices over the octonions. We first review properties of the octonions and the exceptional Jordan algebra, including our previous work on the octonionic Jordan eigenvalue problem. We then examine a particular real, noncompact form of the Lie group E6, which preserves determinants in the exceptional Jordan algebra. Finally, we describe a possible symmetry-breaking scenario within E6: first choose one of the octonionic directions to be special, then choose one of the 2×2 submatrices inside the 3×3 matrices to be special. Making only these two choices, we are able to describe many properties of leptons in a natural way. We further speculate on the ways in which quarks might be similarly encoded.

Manogue, Corinne A.; Dray, Tevian

2010-11-01

299

Experimental and theoretical particle physics. Final report

A brief sketch of the accomplishments made in the past year is given for the following: {epsilon} expansion analysis of weak first-order transitions in the cubic anisotropy model; the non-Abelian Debye screening length beyond leading order; electric-magnetic duality and the heavy quark potential; ice water vapor interface; groups in cold dark matter simulations; Compton scattering on black body photons; nuclear reaction rates in a plasma; comparison of jets from electron-positron interactions and hadronic collisions; the energy-energy correlation in perturbation theory; CPT violation search in the kaon system; regularization of chiral gauge theories; dynamical supersymmetry breaking; electroweak baryogenesis; quenched chiral perturbation theory for heavy-light mesons; testing the chiral behavior of the hadron spectrum; hadron spectrum with Wilson fermions; quenched chiral perturbation theory for baryons; matrix elements of 4-fermion operators with quenched Wilson fermions; classical preheating and decoherence; reheating and thermalization in a simple scalar model; and from quantum field theory to hydrodynamics: transport coefficients and effective kinetic theory.

NONE

1996-07-09

300

Feynman’s laws of quantum dynamics are concisely stated, discussed in comparison with other formulations of quantum mechanics and applied to selected problems in the physical optics of photons and massive particles as well as flavour oscillations. The classical wave theory of light is derived from these laws for the case in which temporal variation of path amplitudes may be neglected,

J. H. Field

2006-01-01

301

Large numbers hypothesis. IV - The cosmological constant and quantum physics

NASA Technical Reports Server (NTRS)

In standard physics quantum field theory is based on a flat vacuum space-time. This quantum field theory predicts a nonzero cosmological constant. Hence the gravitational field equations do not admit a flat vacuum space-time. This dilemma is resolved using the units covariant gravitational field equations. This paper shows that the field equations admit a flat vacuum space-time with nonzero cosmological constant if and only if the canonical LNH is valid. This allows an interpretation of the LNH phenomena in terms of a time-dependent vacuum state. If this is correct then the cosmological constant must be positive.

Adams, P. J.

1983-01-01

302

Santa Cruz Institute for Particle Physics (SCIPP)

Work for the coming year is a logical continuation of the efforts of the past year. Some special highlights of this past year which are discusses in more detail in this report are: (1) The move onto beamline and start of ZEUS data taking. (2) The completion of the SDC technical proposal including a detailed long-term plan for construction. (3) Continuing publication of very detailed physics results from ALEPH concerning {tau} and b physics, and a precision measurement of electroweak and QCD parameters. (4) Completion of very successful data taking for E-791 at Fermilab, with nearly twice as many events recorded as initially proposed. (5) First measurement of beam polarization at the SLC. These efforts have led to about 15 physics publications this past year centered mainly on topics related to QCD, couplings of flavors to the Z{degrees}, and heavy flavor decays. Taken as a whole, the results in jets from LEP, the ratio of hadronic to leptonic decays of the {tau} the leptonic branching fraction of the J/{psi}, and the charmonium mass spectrum provide a very consistent set of values of {alpha}{sub s} at a variety of scales. In particular, they show the running of {alpha}{sub s} by a factor of about three from m{sub r} to m{sub z}. Results from LEP also provide evidence of the triple gluon vertex. Similarly, the measurement of the b{bar b} fraction of Z{degrees} decays, from the MARK II as well as LEP, provide increasingly better measurements of the Z{degree} coupling to b quarks. Combined with earlier precision measurements of the Z{degrees} mass, width, and leptonic branching fractions, the Z{degrees} decays continue to provide a very precise verification of the Standard Model.

Burchat, P.; Dorfan, D.; Litke, A.; Heusch, C.; Sadrozinski, H.; Schalk, T.; Seiden, A.

1992-11-01

303

Santa Cruz Institute for Particle Physics (SCIPP)

Work for the coming year is a logical continuation of the efforts of the past year. Some special highlights of this past year which are discusses in more detail in this report are: (1) The move onto beamline and start of ZEUS data taking. (2) The completion of the SDC technical proposal including a detailed long-term plan for construction. (3) Continuing publication of very detailed physics results from ALEPH concerning [tau] and b physics, and a precision measurement of electroweak and QCD parameters. (4) Completion of very successful data taking for E-791 at Fermilab, with nearly twice as many events recorded as initially proposed. (5) First measurement of beam polarization at the SLC. These efforts have led to about 15 physics publications this past year centered mainly on topics related to QCD, couplings of flavors to the Z[degrees], and heavy flavor decays. Taken as a whole, the results in jets from LEP, the ratio of hadronic to leptonic decays of the [tau] the leptonic branching fraction of the J/[psi], and the charmonium mass spectrum provide a very consistent set of values of [alpha][sub s] at a variety of scales. In particular, they show the running of [alpha][sub s] by a factor of about three from m[sub r] to m[sub z]. Results from LEP also provide evidence of the triple gluon vertex. Similarly, the measurement of the b[bar b] fraction of Z[degrees] decays, from the MARK II as well as LEP, provide increasingly better measurements of the Z[degree] coupling to b quarks. Combined with earlier precision measurements of the Z[degrees] mass, width, and leptonic branching fractions, the Z[degrees] decays continue to provide a very precise verification of the Standard Model.

Burchat, P.; Dorfan, D.; Litke, A.; Heusch, C.; Sadrozinski, H.; Schalk, T.; Seiden, A.

1992-01-01

304

Elementary particle physics at the University of Florida. Annual progress report

This report discusses research in the following areas: theoretical elementary particle physics; experimental elementary particle physics; axion project; SSC detector development; and computer acquisition. (LSP).

Not Available

1991-12-01

305

Physical theories, eternal inflation, and the quantum universe

NASA Astrophysics Data System (ADS)

Infinities in eternal inflation have long been plaguing cosmology, making any predictions highly sensitive to how they are regulated. The problem exists already at the level of semi-classical general relativity, and has a priori nothing to do with quantum gravity. On the other hand, we know that certain problems in semi-classical gravity, for example physics of black holes and their evaporation, have led to understanding of surprising, quantum natures of spacetime and gravity, such as the holographic principle and horizon complementarity. In this paper, we present a framework in which well-defined predictions are obtained in an eternally inflating multiverse, based on the principles of quantum mechanics. We propose that the entire multiverse is described purely from the viewpoint of a single "observer," who describes the world as a quantum state defined on his/her past light cones bounded by the (stretched) apparent horizons. We find that quantum mechanics plays an essential role in regulating infinities. The framework is "gauge invariant," i.e. predictions do not depend on how spacetime is parametrized, as it should be in a theory of quantum gravity. Our framework provides a fully unified treatment of quantum measurement processes and the multiverse. We conclude that the eternally inflating multiverse and many worlds in quantum mechanics are the same. Other important implications include: global spacetime can be viewed as a derived concept; the multiverse is a transient phenomenon during the world relaxing into a supersymmetric Minkowski state. We also present a model of "initial conditions" for the multiverse. By extrapolating our framework to the extreme, we arrive at a picture that the entire multiverse is a fluctuation in the stationary, fractal "mega-multiverse," in which an infinite sequence of multiverse productions occurs. The framework discussed here does not suffer from problems/paradoxes plaguing other measures proposed earlier, such as the youngness paradox and the Boltzmann brain problem.

Nomura, Yasunori

2011-11-01

306

Quantum Physics, Relativity, and Complex Spacetime: Towards a New Synthesis

The positivity of the energy in relativistic quantum mechanics implies that wave functions can be continued analytically to the forward tube T in complex spacetime. For Klein-Gordon particles, we interpret T as an extended (8D) classical phase space containing all 6D classical phase spaces as symplectic submanifolds. The evaluation maps $e_z: f\\\\to f(z)$ of wave functions on T are relativistic

Gerald Kaiser

2009-01-01

307

Ether, the Theory of Relativity and Quantum Physics

\\u000a In this paper we revisit some of the reasons given by Einstein that resulted in his change of mind about the ether from denying\\u000a to defending its existence. The ether proposed by Einstein we call Einstein’s new ether. We consider the potential use of\\u000a Einstein’s new ether in quantum mechanics. The standard model of elementary particles reveals the existence of

Eduardo V. Flores

308

Finite-particle-number approach to physics

Starting from a discrete, self-generating and self-organizing, recursive model and self-consistent interpretive rules we construct: the scale constants of physics (3,10,137,1.7x10/sup 38/); 3+1 Minkowski space with a discrete metric and the algebraic bound ..delta.. is an element of ..delta.. tau is greater than or equal to 1; the Einstein-deBroglie relation; algebraic double slit interference; a single-time momentum-space scattering theory connected to laboratory experience; an approximation to wave functions; local phase severance and hence both distant correlations and separability; baryon number, lepton number, charge and helicity; m/sub p//m/sub e/; a cosmology not in disagreement with current observations.

Noyes, H.P.

1982-10-01

309

Quantum Information in Non-physics Departments at Liberal Arts Colleges

NASA Astrophysics Data System (ADS)

Quantum information and quantum computing have changed our thinking about the basic concepts of quantum physics. These fields have also introduced exciting new applications of quantum mechanics such as quantum cryptography and non-interactive measurement. It is standard to teach such topics only to advanced physics majors who have completed coursework in quantum mechanics. Recent encounters with teaching quantum cryptography to non-majors and a bout of textbook-writing suggest strategies for teaching this interesting material to those without the standard quantum mechanics background. This talk will share some of those strategies.

Westmoreland, Michael

2012-02-01

310

Variance of the quantum dwell time for a nonrelativistic particle

NASA Astrophysics Data System (ADS)

Mun~oz, Seidel, and Muga [Phys. Rev. A 79, 012108 (2009)], following an earlier proposal by Pollak and Miller [Phys. Rev. Lett. 53, 115 (1984)] in the context of a theory of a collinear chemical reaction, showed that suitable moments of a two-flux correlation function could be manipulated to yield expressions for the mean quantum dwell time and mean square quantum dwell time for a structureless particle scattering from a time-independent potential energy field between two parallel lines in a two-dimensional spacetime. The present work proposes a generalization to a charged, nonrelativistic particle scattering from a transient, spatially confined electromagnetic vector potential in four-dimensional spacetime. The geometry of the spacetime domain is that of the slab between a pair of parallel planes, in particular, those defined by constant values of the third (z) spatial coordinate. The mean Nth power, N = 1, 2, 3, ..., of the quantum dwell time in the slab is given by an expression involving an N-flux-correlation function. All these means are shown to be nonnegative. The N = 1 formula reduces to an S-matrix result published previously [G. E. Hahne, J. Phys. A 36, 7149 (2003)]; an explicit formula for N = 2, and of the variance of the dwell time in terms of the S-matrix, is worked out. A formula representing an incommensurability principle between variances of the output-minus-input flux of a pair of dynamical variables (such as the particle's time flux and others) is derived.

Hahne, G. E.

2013-01-01

311

Variance of the quantum dwell time for a nonrelativistic particle

Munoz, Seidel, and Muga [Phys. Rev. A 79, 012108 (2009)], following an earlier proposal by Pollak and Miller [Phys. Rev. Lett. 53, 115 (1984)] in the context of a theory of a collinear chemical reaction, showed that suitable moments of a two-flux correlation function could be manipulated to yield expressions for the mean quantum dwell time and mean square quantum dwell time for a structureless particle scattering from a time-independent potential energy field between two parallel lines in a two-dimensional spacetime. The present work proposes a generalization to a charged, nonrelativistic particle scattering from a transient, spatially confined electromagnetic vector potential in four-dimensional spacetime. The geometry of the spacetime domain is that of the slab between a pair of parallel planes, in particular, those defined by constant values of the third (z) spatial coordinate. The mean Nth power, N= 1, 2, 3, Horizontal-Ellipsis , of the quantum dwell time in the slab is given by an expression involving an N-flux-correlation function. All these means are shown to be nonnegative. The N= 1 formula reduces to an S-matrix result published previously [G. E. Hahne, J. Phys. A 36, 7149 (2003)]; an explicit formula for N= 2, and of the variance of the dwell time in terms of the S-matrix, is worked out. A formula representing an incommensurability principle between variances of the output-minus-input flux of a pair of dynamical variables (such as the particle's time flux and others) is derived.

Hahne, G. E. [NASA/Ames Research Center, M. S. 258-6, Moffett Field, California 94035 (United States)] [NASA/Ames Research Center, M. S. 258-6, Moffett Field, California 94035 (United States)

2013-01-15

312

Particle escapes in an open quantum network via multiple leads

Quantum escape of a particle from an end of a one-dimensional finite region to N semi-infinite leads is discussed from a scattering theory approach. Depending on the potential barrier amplitude at the junction, the probability P(t) for a particle to remain in the finite region at time t shows two different decay behaviors at long times; one is proportional to N{sup 2}/t{sup 3} and another is proportional to 1/(N{sup 2}t). In addition, the velocity V(t) for a particle to leave the finite region, defined from a probability current of the particle position, decays asymptotically as a power of time {approx}1/t, independent of the number of leads and the initial wave function. For a finite time, the probability P(t) decays exponentially in time with a smaller decay rate for a greater number of leads, and the velocity V(t) shows a time oscillation whose amplitude is larger for a greater number of leads. Particle escapes from the both ends of a finite region to multiple leads are also discussed using a different boundary condition.

Taniguchi, Tooru; Sawada, Shin-ichi [School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda City (Japan)

2011-12-15

313

Quantum dot-containing polymer particles with thermosensitive fluorescence.

Composite polymer particles consisting of a solid poly(acrolein-co-styrene) core and a poly(N-vinylcaprolactam) (PVCL) polymer shell doped with CdSe/ZnS semiconductor quantum dots (QDs) were fabricated. The temperature response of the composite particles was observed as a decrease in their hydrodynamic diameter upon heating above the lower critical solution temperature of the thermosensitive PVCL polymer. Embedding QDs in the PVCL shell yields particles whose fluorescence is sensitive to temperature changes. This sensitivity was determined by the dependence of the QD fluorescence intensity on the distances between them in the PVCL shell, which reversibly change as a result of the temperature-driven conformational changes in the polymer. The QD-containing thermosensitive particles were assembled with protein molecules in such a way that they retained their thermosensitive properties, including the completely reversible temperature dependence of their fluorescence response. The composite particles developed can be used as local temperature sensors, as carriers for biomolecules, as well as in biosensing and various bioassays employing optical detection schemes. PMID:22884648

Generalova, Alla N; Oleinikov, Vladimir A; Sukhanova, Alyona; Artemyev, Mikhail V; Zubov, Vitaly P; Nabiev, Igor

2013-01-15

314

Quantum Capacitance: A Perspective from Physics to Nanoelectronics

NASA Astrophysics Data System (ADS)

All materials (including conductors) possess the so-called quantum capacitance, which is present in series with the traditional geometric (electrostatic) capacitance. It is usually a large positive quantity and therefore irrelevant for most materials except for nanostructures. Quantum capacitance has been found to reduce the overall capacitance of nanostructures compared with what is predicted by classical electrostatics. One of many tantalizing recent physical revelations about quantum capacitance is that it can posses a negative value, hence, allowing for the possibility of enhancing (sometimes dramatically) the overall capacitance in some particular material systems—beyond the scaling predicted by classical electrostatics. We provide here a short overview of this subject and review some recent developments.

Hanlumyuang, Yuranan; Sharma, Pradeep

2014-04-01

315

Time evolution of decay of two identical quantum particles

An analytical solution for the time evolution of decay of two identical noninteracting quantum particles seated initially within a potential of finite range is derived using the formalism of resonant states. It is shown that the wave function, and hence also the survival and nonescape probabilities, for factorized symmetric and entangled symmetric or antisymmetric initial states evolve in a distinctive form along the exponentially decaying and nonexponential regimes. Our findings show the influence of the Pauli exclusion principle on decay. We exemplify our results by solving exactly the s-wave {delta} shell potential model.

Garcia-Calderon, Gaston; Mendoza-Luna, Luis Guillermo [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Mexico 01000, Distrito Federal (Mexico)

2011-09-15

316

Identifying Topological Quantum Spin Liquid in Physical Realistic Models

NASA Astrophysics Data System (ADS)

Quantum spin liquids (QSLs) are elusive magnets without magnetism, resisting symmetry breaking even at zero temperature due to strong quantum fluctuations and geometric frustration. The simplest QSLs known theoretically are characterized by topological order, i.e., topological quantum spin liquid, and support fractionalized excitations. However, there is no practical way to directly determine the topological nature of states, such as QSLs. We propose a practical and extremely simple approach, i.e., cylinder construction, to numerically calculate the topological entanglement entropy (TEE), and thereby identify topological order of the state [H. C. Jiang, Z. Wang, and L. Balents, arXiv:1205.4289]. We have successfully applied this approach to a variety of lattice models and S=1/2 Kagome Heisenberg model. By extracting an accurate TEE, we identify a quantum spin liquid with topological order for the first time in physically realistic SU(2)-invariant lattice model. We emphasize that the TEE provides positive, ``smoking gun'' evidence for a topological quantum spin liquid, and excludes any topologically trivial states, including the valence bound solid state. Besides the Kagome Heisenberg model, based on large-scale accurate density-matrix renormalization group studies of numerous long cylinders with circumferences up to 14 lattice spacings, our results [H. C. Jiang, H. Yao, and L. Balents, Physical Review B 86, 024424(2012)], through a combination of the absence of magnetic or VBS order, nonzero spin singlet and triplet gaps, as well as a finite TEE extremely close to ln(2), provide compelling evidence that the two-dimensional ground state of the square J1-J2 Heisenberg model is a topological quantum spin liquid.

Jiang, Hong-Chen

2013-03-01

317

Open Source and Open Access Resources for Quantum Physics Education

NSDL National Science Digital Library

Quantum mechanics is both a topic of great importance to modern science, engineering, and technology, and a topic with many inherent barriers to learning and understanding. Computational resources are vital tools for developing deep conceptual understanding of quantum systems for students new to the subject. This article outlines two projects that are taking an open source/open access approach to create and share teaching and learning resources for quantum physics. The Open Source Physics project provides program libraries, programming tools, example simulations, and pedagogical resources for instructors wishing to give a rich experience to their students. These simulations and student activities are, in turn, being integrated into a world-wide collection of teaching and learning resources available through the Quantum Exchange, a part of the ComPADRE Portal to the National Science Digital Library. Both of these projects use technologies that encourage community development and collaboration. Using these tools, faculty can create learning experiences, share and discuss their content with others, and combine resources in new ways. Examples of the available content and tools are given, along with an introduction to accessing and using these resources.

Belloni, Mario; Christian, Wolfgang; Mason, Bruce

2010-10-14

318

Open Source and Open Access Resources for Quantum Physics Education

NSDL National Science Digital Library

Quantum mechanics is both a topic of great importance to modern science, engineering, and technology, and a topic with many inherent barriers to learning and understanding. Computational resources are vital tools for developing deep conceptual understanding of quantum systems for students new to the subject. This article outlines two projects that are taking an open source/open access approach to create and share teaching and learning resources for quantum physics. The Open Source Physics project provides program libraries, programming tools, example simulations, and pedagogical resources for instructors wishing to give a rich experience to their students. These simulations and student activities are, in turn, being integrated into a world?wide collection of teaching and learning resources available through the Quantum Exchange, a part of the ComPADRE Portal to the National Science Digital Library. Both of these projects use technologies that encourage community development and collaboration. Using these tools, faculty can create learning experiences, share and discuss their content with others, and combine resources in new ways. Examples of the available content and tools are given, along with an introduction to accessing and using these resources.

Belloni, Mario; Christian, Wolfgang; Mason, Bruce

2008-04-28

319

Shock Physics Simulation Using a Hybrid Particle-Element Method

NASA Astrophysics Data System (ADS)

Some important shock physics applications have motivated the development of numerical methods based on mixed particle-finite element formulations. Although pure continuum and pure particle based methods are well suited for use in many shock physics problems, their underlying kinematic schemes limit their utility in selected applications. An example is hypervelocity impact simulation, which requires both accurate modeling of strength effects and general descriptions of contact-impact dynamics for all structures and material fragments. In recent research the hybrid particle-element method of Shivarama and Fahrenthold (Int. J. for Num. Methods in Eng., 2004, Vol. 59, pp. 737-753) has been extended and validated in simulations of one and three dimensional shock physics problems.

Fahrenthold, Eric

2005-07-01

320

NASA Astrophysics Data System (ADS)

In this paper, we explicate a method of quantum hydrodynamics (QHD) for the study of the quantum evolution of a system of polarized particles. Although we focused primarily on the two-dimensional (2D) physical systems, the method is valid for three-dimensional (3D) and one-dimensional (1D) systems too. The presented method is based upon the Schrödinger equation. Fundamental QHD equations for charged and neutral particles were derived from the many-particle microscopic Schrödinger equation. The fact that particles possess the electric dipole moment (EDM) was taken into account. The explicated QHD approach was used to study dispersion characteristics of various physical systems. We analyzed dispersion of waves in a two-dimensional ion and hole gas placed into an external electric field, which is orthogonal to the gas plane. Elementary excitations in a system of neutral polarized particles were studied for 1D, 2D, and 3D cases. The polarization dynamics in systems of both neutral and charged particles is shown to cause formation of a new type of waves as well as changes in the dispersion characteristics of already known waves. We also analyzed wave dispersion in 2D exciton systems, in 2D electron-ion plasma, and in 2D electron-hole plasma. Generation of waves in 3D-system neutral particles with EDM by means of the beam of electrons and neutral polarized particles is investigated.

Andreev, P. A.; Kuzmenkov, L. S.; Trukhanova, M. I.

2011-12-01

321

UK Particle Physics, Astronomy, and Space Science (PPARC): Frontiers

NSDL National Science Digital Library

The Frontiers publication offers the latest news and activities of the Research Council's funded projects and the UK Particle Physics, Astronomy, and Space Science's (PPARC) funded scientists. Produced three times a year, each issue is easy to navigate with quick links to the space science and particle physics articles on the Contents page as well as a keyword search. The website offers archives of the publication since 1997. Each issue contains five sections: the Contents, Editorial, Update, Features, and News. While the other sections contain brief synopses, the Features section offers comprehensive descriptions of stimulating endeavors.

322

Nuclear and particle physics, astrophysics and cosmology (NPAC) capability review

The present document represents a summary self-assessment of the status of the Nuclear and Particle Physics, Astrophysics and Cosmology (NPAC) capability across Los Alamos National Laboratory (LANL). For the purpose of this review, we have divided the capability into four theme areas: Nuclear Physics, Particle Physics, Astrophysics and Cosmology, and Applied Physics. For each theme area we have given a general but brief description of the activities under the area, a list of the Laboratory divisions involved in the work, connections to the goals and mission of the Laboratory, a brief description of progress over the last three years, our opinion of the overall status of the theme area, and challenges and issues.

Redondo, Antonio [Los Alamos National Laboratory

2010-01-01

323

Review of lattice results concerning low energy particle physics

We review lattice results relevant for pion and kaon physics with the aim of making them easily accessible to the particle physics community. Specifically, we review the determination of the light-quark masses, the form factor f_+(0), relevant for the semileptonic K -> pi transition at zero momentum transfer as well as the ratio f_K\\/f_pi of decay constants and discuss the

Gilberto Colangelo; Stephan Durr; Andreas Juttner; Laurent Lellouch; Heinrich Leutwyler; Vittorio Lubicz; Silvia Necco; Christopher T. Sachrajda; Silvano Simula; Anastassios Vladikas; Urs Wenger; Hartmut Wittig

2010-01-01

324

Within the path integral Feynman formulation of quantum mechanics, the fundamental Heisenberg Uncertainty Relationship (HUR) is analyzed in terms of the quantum fluctuation influence on coordinate and momentum estimations. While introducing specific particle and wave representations, as well as their ratio, in quantifying the wave-to-particle quantum information, the basic HUR is recovered in a close analytical manner for a large range of observable particle-wave Copenhagen duality, although with the dominant wave manifestation, while registering its progressive modification with the factor 1-n2, in terms of magnitude n?[0,1]. of the quantum fluctuation, for the free quantum evolution around the exact wave-particle equivalence. The practical implications of the present particle-to-wave ratio as well as of the free-evolution quantum picture are discussed for experimental implementation, broken symmetry and the electronic localization function. PMID:21152325

Putz, Mihai V

2010-01-01

325

The purpose of this study was to characterize the physical and chemical properties of particles generated from the interaction of tires and road surfaces. Morphology, size distribution, and chemical composition were compared between particles generated using different methods, including on-road collection, laboratory generation under simulated driving conditions, and cryogenic breaking of tread rubber. Both on-road collected and laboratory generated particles exhibited the elongated shape typical of tire wear particles, whereas tread particles were more angular. Despite similar morphology for the on-road collected and the laboratory generated particles, the former were smaller on average. It is not clear at this stage if the difference is significant to the physical and chemical behavior of the particles. The chemical composition of the particles differed, with on-road generated particles containing chemical contributions from sources other than tires, such as pavement or particulates generated from other traffic-related sources. Understanding the differences between these particles is essential in apportioning contaminant contributions to the environment between tires, roadways, and other sources, and evaluating the representativeness of toxicity studies using different types of particulate generated. PMID:19896165

Kreider, Marisa L; Panko, Julie M; McAtee, Britt L; Sweet, Leonard I; Finley, Brent L

2010-01-01

326

Subbarrier Fusion Reactions and Many-Particle Quantum Tunneling

NASA Astrophysics Data System (ADS)

Low-energy heavy-ion fusion reactions are governed by quantum tunneling through the Coulomb barrier formed by the strong cancellation of the repulsive Coulomb force with the attractive nuclear interaction between the colliding nuclei. Extensive experimental as well as theoretical studies have revealed that fusion reactions are strongly influenced by couplings of the relative motion of the colliding nuclei to several nuclear intrinsic motions. Heavy-ion subbarrier fusion reactions thus provide a good opportunity to address the general problem of quantum tunneling in the presence of couplings, which has been a popular subject in recent decades in many branches of physics and chemistry. Here, we review theoretical aspects of heavy-ion subbarrier fusion reactions from the viewpoint of quantum tunneling in systems with many degrees of freedom. Particular emphases are put on the coupled-channels approach to fusion reactions and the barrier distribution representation for multichannel penetrability. We also discuss an application of the barrier distribution method to elucidate the mechanism of the dissociative adsorption of H_2 molecules in surface science.

Hagino, K.; Takigawa, N.

2012-12-01

327

Classical and Quantum Mechanical Models of Many-Particle Systems

The topic of this meeting were non-linear partial differential and integro-differential equations (in particular kinetic equations and their macroscopic\\/fluid-dynamical limits) modeling the dynamics of many-particle systems with applications in physics, engineering, and mathematical biol- ogy. Typical questions of interest were the derivation of macro-models from micro-models, the mathematical analysis (well-posedness, stability, asymp- totic behavior of solutions), and -to a lesser

Anton Arnold; Carlo Cercignani; Laurent Desvillettes

2006-01-01

328

Current experiments in elementary particle physics. Revision 1-85

This report contains summaries of 551 approved experiments in elementary particle physics (experiments that finished taking data before 1 January 1980 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Moscow Institute of Theoretical and Experimental Physics, Tokyo Institute of Nuclear Studies, KEK, LAMPF, Leningrad Nuclear Physics Institute, Saclay, Serpukhov, SIN, SLAC, and TRIUMF, and also experiments on proton decay. Properties of the fixed-target beams at most of the laboratories are summarized. Instructions are given for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

Wohl, C.G.; Armstrong, F.E.; Rittenberg, A.; Trippe, T.G.; Yost, G.P.; Oyanagi, Y.; Dodder, D.C.; Grudtsin, S.N.; Ryabov, Yu.G.; Frosch, R.

1985-01-01

329

NASA Astrophysics Data System (ADS)

In quantum physics the free particle and the harmonically trapped particle are arguably the most important systems a physicist needs to know about. It is little known that, mathematically, they are one and the same. This knowledge helps us to understand either from the viewpoint of the other. Here we show that all general time-dependent solutions of the free-particle Schrödinger equation can be mapped to solutions of the Schrödinger equation for harmonic potentials, both the trapping oscillator and the inverted "oscillator". This map is fully invertible and therefore induces an isomorphism between both types of system, they are equivalent. A composition of the map and its inverse allows us to map from one harmonic oscillator to another with a different spring constant and different center position. The map is independent of the state of the system, consisting only of a coordinate transformation and multiplication by a form factor, and can be chosen such that the state is identical in both systems at one point in time. This transition point in time can be chosen freely, the wave function of the particle evolving in time in one system before the transition point can therefore be linked up smoothly with the wave function for the other system and its future evolution after the transition point. Such a cut-and-paste procedure allows us to describe the instantaneous changes of the environment a particle finds itself in. Transitions from free to trapped systems, between harmonic traps of different spring constants or center positions, or, from harmonic binding to repulsive harmonic potentials are straightforwardly modelled. This includes some time-dependent harmonic potentials. The mappings introduced here are computationally more efficient than either state-projection or harmonic oscillator propagator techniques conventionally employed when describing instantaneous (non-adiabatic) changes of a quantum particle's environment.

Steuernagel, Ole

2014-06-01

330

Spectral Theory of Automorphism Groups and Particle Structures in Quantum Field Theory

NASA Astrophysics Data System (ADS)

This Thesis presents some physically motivated criteria for the existence of particles and infra-particles in a given quantum field theory. It is based on a refined spectral theory of automorphism groups describing the energy-momentum transfer of local observables. In particular, a novel decomposition of the algebra of local observables into spectral subspaces is constructed. Apart from the counterparts of the pure-point and absolutely continuous subspaces, familiar from the spectral theory of operators, there appears a new 'point-continuous' subspace. It belongs to the singular-continuous part of the decomposition, but is finite-dimensional in a large class of models; its dimension carries information about the infrared structure of a theory. It is shown that this point-continuous subspace is trivial in all theories complying with a regularity condition proposed in this work. Moreover, this condition entails the existence of particles if the theory admits a stress-energy tensor. The uniqueness of the decomposition of the algebra of observables into the pure-point and continuous subspace is established by proving an ergodic theorem for automorphism groups. The proof is based on physically motivated phase space conditions which have a number of interesting consequences pertaining to the vacuum structure such as the convergence of physical states to a unique vacuum under large timelike translations.

Dybalski, Wojciech

2009-01-01

331

My 50 years of research in particle physics

Some of my work of the last 50 years in the field of theoretical particle physics is described with particular emphasis on the motivation, the process of investigation, relationship to the work of others, and its impact. My judgment is unavoidably subjective, although I do present the comments of other researchers as much as possible.

Sugawara, Hirotaka

2010-01-01

332

The heavy particle hazard, what physical data are needed?

NASA Technical Reports Server (NTRS)

The physical data required to evaluate the radiation hazard from heavy galactic cosmic rays to astronauts on extended missions are discussed. The spectral characteristics, nuclear interaction parameters, and track structure of particles are emphasized. The data on the lower energy portion of the differential spectrum of the iron group and nuclear fragmentation in tissue and aluminum are tested, and results are shown.

Curtis, S. B.; Wilkinson, M. C.

1972-01-01

333

My 50 years of research in particle physics.

Some of my work of the last 50 years in the field of theoretical particle physics is described with particular emphasis on the motivation, the process of investigation, relationship to the work of others, and its impact. My judgment is unavoidably subjective, although I do present the comments of other researchers as much as possible. PMID:20431257

Sugawara, Hirotaka

2010-01-01

334

Studies in theoretical high energy particle physics. Technical progress report, [1991--1992

Theoretical work on the following topics is briefly summarized: symmetry structure of conformal affine Toda model and KP hierarchy; solitons in the affine Toda and conformal affine Toda models; classical r-matrices and Poisson bracket structures on infinite-dimensional groups; R-matrix formulation of KP hierarchies and their gauge equivalence; statistics of particles and solitons; charge quantization in the presence of an Alice string; knotting and linking of nonabelian flux; electric dipole moments; neutrino physics in gauge theories; CP violation in the high energy colliders; supersymmetric quantum mechanics; parton structure functions in nuclei; dual parton model. 38 refs.

Aratyn, H.; Brekke, L.; Keung, Wai-Yee; Sukhatme, U.

1993-01-01

335

Magnetic particle motions within living cells. Physical theory and techniques.

Body tissues are not ferromagnetic, but ferromagnetic particles can be present as contaminants or as probes in the lungs and in other organs. The magnetic domains of these particles can be aligned by momentary application of an external magnetic field; the magnitude and time course of the resultant remanent field depend on the quantity of magnetic material and the degree of particle motion. The interpretation of magnetometric data requires an understanding of particle magnetization, agglomeration, random motion, and both rotation and translation in response to magnetic fields. We present physical principles relevant to magnetometry and suggest models for intracellular particle motion driven by thermal, elastic, or cellular forces. The design principles of instrumentation for magnetizing intracellular particles and for detecting weak remanent magnetic fields are described. Such magnetic measurements can be used for noninvasive studies of particle clearance from the body or of particle motion within body tissues and cells. Assumptions inherent to this experimental approach and possible sources of artifact are considered and evaluated.

Valberg, P A; Butler, J P

1987-01-01

336

Ensembles of physical states and random quantum circuits on graphs

NASA Astrophysics Data System (ADS)

In this paper we continue and extend the investigations of the ensembles of random physical states introduced in Hamma [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.109.040502 109, 040502 (2012)]. These ensembles are constructed by finite-length random quantum circuits (RQC) acting on the (hyper)edges of an underlying (hyper)graph structure. The latter encodes for the locality structure associated with finite-time quantum evolutions generated by physical, i.e., local, Hamiltonians. Our goal is to analyze physical properties of typical states in these ensembles; in particular here we focus on proxies of quantum entanglement as purity and ?-Renyi entropies. The problem is formulated in terms of matrix elements of superoperators which depend on the graph structure, choice of probability measure over the local unitaries, and circuit length. In the ?=2 case these superoperators act on a restricted multiqubit space generated by permutation operators associated to the subsets of vertices of the graph. For permutationally invariant interactions the dynamics can be further restricted to an exponentially smaller subspace. We consider different families of RQCs and study their typical entanglement properties for finite time as well as their asymptotic behavior. We find that area law holds in average and that the volume law is a typical property (that is, it holds in average and the fluctuations around the average are vanishing for the large system) of physical states. The area law arises when the evolution time is O(1) with respect to the size L of the system, while the volume law arises as is typical when the evolution time scales like O(L).

Hamma, Alioscia; Santra, Siddhartha; Zanardi, Paolo

2012-11-01

337

Geometry of the physical phase space in quantum gauge systems

NASA Astrophysics Data System (ADS)

The physical phase space in gauge systems is studied. Simple soluble gauge models are considered in detail. Effects caused by a non-Euclidean geometry of the physical phase space in quantum gauge models are described in the operator and path integral formalisms. The projection on the Dirac gauge invariant states is used to derive a necessary modification of the Hamiltonian path integral in gauge theories of the Yang-Mills type with fermions that takes into account the non-Euclidean geometry of the physical phase space. The new path integral is applied to resolve the Gribov obstruction. Applications to the Kogut-Susskind lattice gauge theory are given. The basic ideas are illustrated with examples accessible for non-specialists.

Shabanov, Sergei V.

2000-03-01

338

Dispersion of waves in a weakly relativistic quantum plasma and beam of particles

NASA Astrophysics Data System (ADS)

A brief review of works devoted to quantum hydrodynamics is given. A system of quantum hydrodynamics equations is presented for a weakly relativistic system of charged particles described by the Darwin Hamiltonian. This system of equations involves the continuity equation and the momentum balance equation for such system of particles. The role of the quantum terms in the momentum balance equation is analyzed. As an illustration of principally new effects arising in the examined approximation, longitudinal waves in electron quantum plasma and waves in a beam of charged particles are considered.

Ivanov, A. Yu.; Andreev, P. A.

2013-08-01

339

Particle radiosurgery: A new frontier of physics in medicine.

Radiosurgery was introduced over half a century ago for treatment of intracranial lesions. In more recent years, stereotactic radiotherapy has rapidly advanced and is now commonly used for treatments of both cranial and extracranial lesions with high doses delivered in a few, down to a single fraction. The results of a workshop on Particle radiosurgery: A new frontier of physics in medicine held at Obergurgl, Austria during August 25-29 2013 are summarized in this issue with an overview presented in this paper. The focus was laid on particle radiosurgery but the content also includes current practice in x-ray radiosurgery and the overarching research in radiobiology and motion management for extracranial lesions. The results and discussions showed that especially research in radiobiology of high-dose charged-particles and motion management are necessary for the success of particle radiosurgery. PMID:24889154

Bert, Christoph; Durante, Marco

2014-07-01

340

Entropic Lower Bound for the Quantum Scattering of Spinless Particles

NASA Astrophysics Data System (ADS)

In this paper the angle-angular momentum entropic lower bound is proved by using Tsallis-like entropies and Riesz theorem for the quantum scattering of the spinless particles. Numerical estimations of the scattering entropies, as well as an experimental test of the state-independent entropic lower bound, are obtained by using the amplitude reconstruction from the available phase shift analyses for the pion-nucleus scatterings. A standard interpretation of these results in terms of the optimal state dominance is presented. Then, it is shown that experimental pion-nucleus entropies are well described by optimal entropies and that the experimental data are consistent with the principle of minimum distance in the space of scattering states.

Ion, D. B.; Ion, M. L. D.

1998-12-01

341

The physical underpinning of security proofs for quantum key distribution

NASA Astrophysics Data System (ADS)

The dawn of quantum technology unveils a plethora of new possibilities and challenges in the world of information technology, one of which is the quest for secure information transmission. A breakthrough in classical algorithm or the development of a quantum computer could threaten the security of messages encoded using public key cryptosystems based on one-way function such as RSA. Quantum key distribution (QKD) offers an unconditionally secure alternative to such schemes, even in the advent of a quantum computer, as it does not rely on mathematical or technological assumptions, but rather on the universality of the laws of quantum mechanics. Physical concepts associated with quantum mechanics, like the uncertainty principle or entanglement, paved the way to the first successful security proof for QKD. Ever since, further development in security proofs for QKD has been remarkable. But the connection between entanglement distillation and the uncertainty principle has remained hidden under a pile of mathematical burden. Our main goal is to dig the physics out of the new advances in security proofs for QKD. By introducing an alternative definition of private state, which elaborates the ideas of Mayers and Koashi, we explain how the security of all QKD protocols follows from an entropic uncertainty principle. We show explicitly how privacy amplification protocol can be reduced to a private state distillation protocol constructed from our observations about the uncertainty principle. We also derive a generic security proof for one-way permutation-invariant QKD protocols. Considering collective attack, we achieve the same secret key generation rate as the Devetak-Winter's bound. Generalizing an observation from Kraus, Branciard and Renner, we have provided an improved version of the secret key generation rates by considering a different symmetrization. In certain situations, we argue that Azuma's inequality can simplify the security proof considerably, and we explain the implication, on the security level, of reducing a QKD protocol to an entanglement or a more general private state distillation protocol. In a different direction, we introduce a QKD protocol with multiple-photon encoding that can be implemented without a shared reference frame. We prove the unconditional security of this protocol, and discuss some features of the efficiency of multiple-photon QKD schemes in general.

Boileau, Jean Christian

342

Physical facets of ultrasonic cavitational synthesis of zinc ferrite particles.

This paper addresses the physical features of the ultrasonic cavitational synthesis of zinc ferrite particles and tries to establish the relationship between cavitation physics and sonochemistry of the zinc ferrite synthesis. A dual approach of coupling experimental results with simulations of radial motion of cavitation bubbles has been adopted. The precursors for the zinc ferrite, viz. ZnO and Fe(3)O(4) are produced in situ by the hydrolysis of Zn and Fe(II) acetates stimulated by (*)OH radicals produced from the transient collapse of the cavitation bubbles. Experiments performed under different conditions create significant variation in the production of (*)OH radicals, and hence, the rate of acetate hydrolysis. Correlation of the results of experiments and simulations sheds light on the important facets of the physical mechanism of ultrasonic cavitational zinc ferrite synthesis. It is revealed that too much or too little rate of acetate hydrolysis results in smaller particle size of zinc ferrite. The first effect of a higher rate of hydrolysis leads to excessively large growth of particles, due to which they become susceptible to the disruptive action of cavitation bubbles. Whereas, the second effect of too small rate of hydrolysis of Zn and Fe(II) acetates restricts the growth of particles. It has been observed that the initial reactant concentration does not influence the mean particle size or the size distribution of zinc ferrite particles. The present investigation clearly confirms that the rate-controlling step of zinc ferrite synthesis through ultrasonic cavitational route is the rate of formation of (*)OH radicals from cavitation bubbles. PMID:19880340

Reddy, Bhaskar Rao; Sivasankar, Thirugnanasambandam; Sivakumar, Manickam; Moholkar, Vijayanand S

2010-02-01

343

Decoherence in two-dimensional quantum walks using four- and two-state particles

NASA Astrophysics Data System (ADS)

We study the decoherence effects originating from state flipping and depolarization for two-dimensional discrete-time quantum walks using four- and two-state particles. By comparing the quantum correlations between the two spatial (x - y) degrees of freedom using measurement-induced disturbance, we show that the two schemes using a two-state particle are more robust against decoherence than the Grover walk, which uses a four-state particle. We also show that the symmetries which hold for two-state quantum walks break down for the Grover walk, adding to the various other advantages of using two-state rather than four-state particles.

Chandrashekar, C. M.; Busch, T.

2013-03-01

344

A guide to experimental particle physics literature, 1991-1996

We present an indexed guide to experimental particle physics literature for the years 1991 - 1996. Approximately 4200 papers are indexed by (1) Beam/Target/Momentum (2) Reaction/Momentum/Data-Descriptor (including the final state) (3) Particle/Decay (4) Accelerator/Experiment/Detector. All indices are cross-referenced to the paper`s title and references in the ID/Reference/Title index. The information presented in this guide is also publicly available on a regularly-updated DATAGUIDE database from the World Wide Web.

Ezhela, V.V.; Filimonov, B.B.; Lugovsky, S.B. [Inst. for High Energy Physics, Moscow (Russian Federation)] [and others

1996-10-01

345

NSDL National Science Digital Library

This web site provides interactive representations of quantum optics experiments. The illustrations show the setup, operation, and results of real experiments that demonstrate fundamental phenomena of quantum physics such as quantum particles, randomness, and entanglement as well as prospective applications such as quantum number generation and quantum cryptography. Extensive supplemental materials, with text, pictures, and video, explain the physics being studied in the experiments. An extensive bibliography is also included.

Meyn, Jan-Peter; Bronner, Patrick

2009-02-17

346

Lattice quantum chromodynamics at the physical point and beyond

NASA Astrophysics Data System (ADS)

We review the work of the PACS-CS Collaboration, which aimed to realize lattice quantum chromodynamics (QCD) calculations at the physical point, i.e., those with quark masses set at physical values. This has been a long-term goal of lattice QCD simulation since its inception in 1979. After reviewing the algorithmic progress, which played a key role in this development, we summarize the simulations that explored the quark mass dependence of hadron masses down to values close to the physical point. In addition to allowing a reliable determination of the light hadron mass spectrum, this work provided clues on the validity range of chiral perturbation theory, which is widely used in phenomenology. We then describe the application of the technique of quark determinant reweighting, which enables lattice QCD calculations exactly on the physical point. The physical quark masses and the strong coupling constants are fundamental constants of the strong interaction. We describe a non-perturbative Schrödinger functional approach to figure out the non-perturbative renormalization needed to calculate them. There are a number of physical applications that can benefit from lattice QCD calculations carried out either near or at the physical point. We take up three illustrative examples: calculation of the physical properties of the ? meson as a resonance, the electromagnetic form factor and charge radius of the pion, and charmed meson spectroscopy. Bringing single hadron properties under control opens up a number of new areas for serious lattice QCD research. One such area is electromagnetic effects in hadronic properties. We discuss the combined QCD plus QED simulation strategy and present results on electromagnetic mass difference. Another area is multi-hadron states, or nuclei. We discuss the motivations and difficulties in this area, and describe our work for deuteron and helium as our initial playground. We conclude with a brief discussion on the future perspective of lattice QCD.

Aoki, S.; Ishii, N.; Ishikawa, K.-I.; Ishizuka, N.; Izubuchi, T.; Kadoh, D.; Kanaya, K.; Kuramashi, Y.; Namekawa, Y.; Nguyen, O. H.; Okawa, M.; Sasaki, K.; Taniguchi, Y.; Ukawa, A.; Ukita, N.; Yamazaki, T.; Yoshié, T.; PACS-CS Collaboration

2012-08-01

347

Hilbert space, the number of Higgs particles and the quantum two-slit experiment

Rigorous mathematical formulation of quantum mechanics requires the introduction of a Hilbert space. By contrast, the Cantorian E-infinity approach to quantum physics was developed largely without any direct reference to the afore mentioned mathematical spaces. In the present work we present a novel reinterpretation of basic ?(?) Cantorian spacetime relations in terms of the Hilbert space of quantum mechanics. In

M. S. El Naschie

2006-01-01

348

Review of lattice results concerning low-energy particle physics

We review lattice results relevant for pion and kaon physics with the aim of making them easily accessible to the particle\\u000a physics community. Specifically, we review the determination of the light-quark masses, the form factor f\\u000a +(0), relevant for the semileptonic K?? transition at zero momentum transfer as well as the ratio f\\u000a \\u000a K\\u000a \\/f\\u000a \\u000a ?\\u000a of decay constants and

G. Colangelo; S. Dürr; A. Jüttner; L. Lellouch; H. Leutwyler; V. Lubicz; S. Necco; C. T. Sachrajda; S. Simula; A. Vladikas; U. Wenger; H. Wittig

2011-01-01

349

Quantum-logic clocks for fundamental physics and geodesy

NASA Astrophysics Data System (ADS)

We have compared the rates of two quantum-logic clocks based on the optical ^1S0-^3P0 transition in Al^+. The performance of the newer clock is unmatched, and despite many differences, their rates agree to 1.8 ±0.7 x10-17, within the accuracy limit of the older clock. The newer clock has an accuracy of 8.6 x10-18 and stability near 10-15 (?/s)-1/2. Quantum-correlation spectroscopy yields an improved measurement stability of 3.7x10-16 (?/s)-1/2. This technique also allows Q-factors beyond 6x10^15 to be seen. This is the highest observed Q-factor in physics. The talk will discuss the basic operation of quantum-logic clocks based on Al^+, together with recent results that include a first geo-potential difference measurement, and constraints on the temporal variation of the fine-structure constant. Potential uses of entangled states in such clocks are also explored.

Rosenband, Till

2011-03-01

350

Materials for Active Engagement in Nuclear and Particle Physics Courses

NASA Astrophysics Data System (ADS)

Physics education researchers have developed a rich variety of research-based instructional strategies that now permeate many introductory courses. Carrying these active-engagement techniques to upper-division courses requires effort and is bolstered by experience. Instructors interested in these methods thus face a large investment of time to start from scratch. This NSF-TUES grant, aims to develop, test and disseminate active-engagement materials for nuclear and particle physics topics. We will present examples of these materials, including: a) Conceptual discussion questions for use with Peer Instruction; b) warm-up questions for use with Just in Time Teaching, c) ``Back of the Envelope'' estimation questions and small-group case studies that will incorporate use of nuclear and particle databases, as well as d) conceptual exam questions.

Loats, Jeff; Schwarz, Cindy; Krane, Ken

2013-04-01

351

UCLA Particle Physics Research Group annual progress report

The objectives, basic research programs, recent results, and continuing activities of the UCLA Particle Physics Research Group are presented. The objectives of the research are to discover, to formulate, and to elucidate the physics laws that govern the elementary constituents of matter and to determine basic properties of particles. The research carried out by the Group last year may be divided into three separate programs: (1) baryon spectroscopy, (2) investigations of charge symmetry and isospin invariance, and (3) tests of time reversal invariance. The main body of this report is the account of the techniques used in our investigations, the results obtained, and the plans for continuing and new research. An update of the group bibliography is given at the end.

Nefkens, B.M.K.

1983-11-01

352

Physical sputtering of metallic systems by charged-particle impact

The present paper provides a brief overview of our current understanding of physical sputtering by charged-particle impact, with the emphasis on sputtering of metals and alloys under bombardment with particles that produce knock-on collisions. Fundamental aspects of ion-solid interactions, and recent developments in the study of sputtering of elemental targets and preferential sputtering in multicomponent materials are reviewed. We concentrate only on a few specific topics of sputter emission, including the various properties of the sputtered flux and depth of origin, and on connections between sputtering and other radiation-induced and -enhanced phenomena that modify the near-surface composition of the target. The synergistic effects of these diverse processes in changing the composition of the integrated sputtered-atom flux is described in simple physical terms, using selected examples of recent important progress. 325 refs., 27 figs.

Lam, N.Q.

1989-12-01

353

Current experiments in elementary-particle physics - March 1983

Microfiche are included which contain summaries of 479 experiments in elementary particle physics. Experiments are included at the following laboratories: Brookhaven (BNL); CERN; CESR; DESY; Fermilab (FNAL); Institute for Nuclear Studies (INS); KEK; LAMPF; Serpukhov (SERP); SIN; SLAC; and TRIUMF. Also, summaries of proton decay experiments are included. A list of experiments and titles is included; and a beam-target-momentum index and a spokesperson index are given. Properties of beams at the facilities are tabulated. (WHK)

Wohl, C.G.; Armstrong, F.E.; Rittenberg, A.

1983-03-01

354

Theoretical and Experimental Studies of Elementary Particle Physics

The elementary particle physics research program at Indiana University spans a broad range of the most interesting topics in this fundamental field, including important contributions to each of the frontiers identified in the recent report of HEPAP's Particle Physics Prioritization Panel: the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. Experimentally, we contribute to knowledge at the Energy Frontier through our work on the D0 and ATLAS collaborations. We work at the Intensity Frontier on the MINOS and NOvA experiments and participate in R&D for LBNE. We are also very active on the theoretical side of each of these areas with internationally recognized efforts in phenomenology both in and beyond the Standard Model and in lattice QCD. Finally, although not part of this grant, members of the Indiana University particle physics group have strong involvement in several astrophysics projects at the Cosmic Frontier. Our research efforts are divided into three task areas. The Task A group works on D0 and ATLAS; Task B is our theory group; and Task C contains our MINOS, NOvA, and LBNE (LArTPC) research. Each task includes contributions from faculty, senior scientists, postdocs, graduate and undergraduate students, engineers, technicians, and administrative personnel. This work was supported by DOE Grant DE-FG02-91ER40661. In the following, we describe progress made in the research of each task during the final period of the grant, from November 1, 2009 to April 30, 2013.

Evans, Harold G [Indiana University] [Indiana University; Kostelecky, V Alan [Indiana University] [Indiana University; Musser, James A [Indiana University] [Indiana University

2013-07-29

355

New ways to engage the public with quantum physics

NASA Astrophysics Data System (ADS)

We are a few french condensed matter physicists involved in developping new routes to engage the public with our research field. We have worked with designers, graphists, artists, teachers and the public to produce original tools for outreach. In this talk, we will present some of them : *demonstration tools such as a superconducting circus or a levitating Eiffel Tower *futuristic videos (what life would be if room temperature superconductivity was achieved?) *graphic animations to make quantum physic simple and appealing *websites about quantum physics or superconductivity ( www.quantummadesimple.com or www.superconductivity.eu ) *folding activities for kids to understand orbitals and superconductivity We will also discuss the engagement of condensed matter physicists in outreach activities. Many of us find it hard to get involved : ``not enough time'', ``my field is to complex to be popularized'', ``not good for my career'', ``science museums do it better''... We will give some insight of how we could overcome this reluctance among our colleagues and get many french researchers involved in engaging the public over the past two years. All our activities and productions can be found in English at the website: www.vulgarisation.fr

Bobroff, Julien

2013-03-01

356

NASA Astrophysics Data System (ADS)

Probability plays a critical role in making sense of quantum physics, but most science and engineering undergraduates have very little experience with the topic. A probabilistic interpretation of a physical system, even at a classical level, is often completely new to them, and the relevant fundamental concepts such as the probability distribution and probability density are rarely understood. To address these difficulties and to help students build a model of how to think about probability in physical systems, we have developed a set of hands-on tutorial activities appropriate for use in a modern physics course for engineers. We discuss some student difficulties with probability concepts and an instructional approach that uses a random picture metaphor and digital video technology.

Bao, Lei; Redish, Edward F.

2002-03-01

357

Relational particle models: I. Reconciliation with standard classical and quantum theory

NASA Astrophysics Data System (ADS)

This paper concerns the absolute versus relative motion debate. The Barbour and Bertotti (1982) work may be viewed as an indirectly set up relational formulation of a portion of Newtonian mechanics. I consider further direct formulations of this and argue that the portion in question—universes with zero total angular momentum that are conservative and with kinetic terms that are (homogeneous) quadratic in their velocities—is capable of accommodating a wide range of classical physics phenomena. Furthermore, as I develop in paper II, this relational particle model is a useful toy model for canonical general relativity. I consider what happens if one quantizes relational rather than absolute mechanics, indeed whether the latter is misleading. By exploiting Jacobi coordinates, I show how to access many examples of quantized relational particle models and then interpret these from a relational perspective. By these means, previous suggestions of bad semiclassicality for such models can be eluded. I show how small (particle number) universe relational particle model examples display eigenspectrum truncation, gaps, energy interlocking and counterbalanced total angular momentum. These features mean that these small universe models make interesting toy models for some aspects of closed-universe quantum cosmology. Meanwhile, these features do not compromise the recovery of reality as regards the practicalities of experimentation in a large universe such as our own.

Anderson, Edward

2006-04-01

358

Research in particle physics. Progress report, June 1, 1992--January 31, 1993

Research accomplishments and current activities of Boston University researchers in high energy physics are presented. Principal areas of activity include the following: detectors for studies of electron{endash}positron annihilation in colliding beams; advanced accelerator component design, including the superconducting beam inflector, electrostatic quadrupoles, and the ``electrostatic muon kicker``; the detector for the MACRO (Monopole, Astrophysics, and Cosmic Ray Observatory) experiment; neutrino astrophysics and the search for proton decay; theoretical particle physics (electroweak and flavor symmetry breaking, hadron collider phenomenology, cosmology and astrophysics, new field-theoretic models, nonperturbative investigations of quantum field theories, electroweak interactions); measurement of the anomalous magnetic moment of the muon; calorimetry for the GEM experiment; and muon detectors for the GEM experiment at the Superconducting Super Collider.

Not Available

1992-09-01

359

Dynamical coherent states and physical solutions of quantum cosmological bounces

A new model is studied which describes the quantum behavior of transitions through an isotropic quantum cosmological bounce in loop quantum cosmology sourced by a free and massless scalar field. As an exactly solvable model even at the quantum level, it illustrates properties of dynamical coherent states and provides the basis for a systematic perturbation theory of loop quantum gravity.

Martin Bojowald

2007-01-01

360

EDITORIAL: Focus on Dark Matter and Particle Physics

NASA Astrophysics Data System (ADS)

The quest for the nature of dark matter has reached a historical point in time, with several different and complementary experiments on the verge of conclusively exploring large portions of the parameter space of the most theoretically compelling particle dark matter models. This focus issue on dark matter and particle physics brings together a broad selection of invited articles from the leading experimental and theoretical groups in the field. The leitmotif of the collection is the need for a multi-faceted search strategy that includes complementary experimental and theoretical techniques with the common goal of a sound understanding of the fundamental particle physical nature of dark matter. These include theoretical modelling, high-energy colliders and direct and indirect searches. We are confident that the works collected here present the state of the art of this rapidly changing field and will be of interest to both experts in the topic of dark matter as well as to those new to this exciting field. Focus on Dark Matter and Particle Physics Contents DARK MATTER AND ASTROPHYSICS Scintillator-based detectors for dark matter searches I S K Kim, H J Kim and Y D Kim Cosmology: small-scale issues Joel R Primack Big Bang nucleosynthesis and particle dark matter Karsten Jedamzik and Maxim Pospelov Particle models and the small-scale structure of dark matter Torsten Bringmann DARK MATTER AND COLLIDERS Dark matter in the MSSM R C Cotta, J S Gainer, J L Hewett and T G Rizzo The role of an e+e- linear collider in the study of cosmic dark matter M Battaglia Collider, direct and indirect detection of supersymmetric dark matter Howard Baer, Eun-Kyung Park and Xerxes Tata INDIRECT PARTICLE DARK MATTER SEARCHES:EXPERIMENTS PAMELA and indirect dark matter searches M Boezio et al An indirect search for dark matter using antideuterons: the GAPS experiment C J Hailey Perspectives for indirect dark matter search with AMS-2 using cosmic-ray electrons and positrons B Beischer, P von Doetinchem, H Gast, T Kirn and S Schael Axion searches with helioscopes and astrophysical signatures for axion(-like) particles K Zioutas, M Tsagri, Y Semertzidis, T Papaevangelou, T Dafni and V Anastassopoulos The indirect search for dark matter with IceCube Francis Halzen and Dan Hooper DIRECT DARK MATTER SEARCHES:EXPERIMENTS Gaseous dark matter detectors G Sciolla and C J Martoff Search for dark matter with CRESST Rafael F Lang and Wolfgang Seidel DIRECT AND INDIRECT PARTICLE DARK MATTER SEARCHES:THEORY Dark matter annihilation around intermediate mass black holes: an update Gianfranco Bertone, Mattia Fornasa, Marco Taoso and Andrew R Zentner Update on the direct detection of dark matter in MSSM models with non-universal Higgs masses John Ellis, Keith A Olive and Pearl Sandick Dark stars: a new study of the first stars in the Universe Katherine Freese, Peter Bodenheimer, Paolo Gondolo and Douglas Spolyar Determining the mass of dark matter particles with direct detection experiments Chung-Lin Shan The detection of subsolar mass dark matter halos Savvas M Koushiappas Neutrino coherent scattering rates at direct dark matter detectors Louis E Strigari Gamma rays from dark matter annihilation in the central region of the Galaxy Pasquale Dario Serpico and Dan Hooper DARK MATTER MODELS The dark matter interpretation of the 511 keV line Céline Boehm Axions as dark matter particles Leanne D Duffy and Karl van Bibber Sterile neutrinos Alexander Kusenko Dark matter candidates Lars Bergström Minimal dark matter: model and results Marco Cirelli and Alessandro Strumia Shedding light on the dark sector with direct WIMP production Partha Konar, Kyoungchul Kong, Konstantin T Matchev and Maxim Perelstein Axinos as dark matter particles Laura Covi and Jihn E Kim

Aprile, Elena; Profumo, Stefano

2009-10-01

361

NASA Astrophysics Data System (ADS)

We employ the theoretical framework of positive operator valued measures, to study Markovian open quantum systems. In particular, we discuss how a quantum system influences its environment. Using the theory of indirect measurements, we then draw conclusions about the information we could hypothetically obtain about the system by observing the environment. Although the environment is not actually observed, we can use these results to describe the change of the quantum system due to its interaction with the environment. We apply this technique to two different problems. In the first part, we study the coherently driven dynamics of a particle on a rail of quantum dots. This tunnelling between adjacent quantum dots can be controlled externally. We employ an adiabatic scheme similar to stimulated Raman adiabatic passage, to transfer the particle between different quantum dots. We compare two fundamentally different sources of decoherence. In the second part, we study the dynamics of a free quantum particle, which experiences random collisions with gas particles. Previous studies on this topic applied scattering theory to momentum eigenstates. We present a supplementary approach, where we develop a rigorous measurement interpretation of the collision process to derive a master equation. Finally, we study the collisional decoherence process in terms of the Wigner function. We restrict ourselves to one spatial dimension. Nevertheless, we find some interesting new insight, including that the previously celebrated quantum contribution to position diffusion is not real, but a consequence of the Markovian approximation. Further, we discover that the leading decoherence process is due to phase averaging, rather than induced by the information transfer between the colliding particles.

Kamleitner, Ingo

2010-09-01

362

Physical interactions of charged particles for radiotherapy and space applications.

In this paper, the basic physics by which energetic charged particles deposit energy in matter is reviewed. Energetic charged particles are used for radiotherapy and are encountered in spaceflight, where they pose a health risk to astronauts. They interact with matter through nuclear and electromagnetic forces. Deposition of energy occurs mostly along the trajectory of the incoming particle, but depending on the type of incident particle and its energy, there is some nonzero probability for energy deposition relatively far from the nominal trajectory, either due to long-ranged knock-on electrons (sometimes called delta rays) or from the products of nuclear fragmentation, including neutrons. In the therapy setting, dose localization is of paramount importance, and the deposition of energy outside nominal treatment volumes complicates planning and increases the risk of secondary cancers as well as noncancer effects in normal tissue. Statistical effects are also important and will be discussed. In contrast to radiation therapy patients, astronauts in space receive comparatively small whole-body radiation doses from energetic charged particles and associated secondary radiation. A unique aspect of space radiation exposures is the high-energy heavy-ion component of the dose. This is not present in terrestrial exposures except in carbon-ion radiotherapy. Designers of space missions must limit exposures to keep risk within acceptable limits. These limits are, at present, defined for low-Earth orbit, but not for deep-space missions outside the geomagnetosphere. Most of the uncertainty in risk assessment for such missions comes from the lack of understanding of the biological effectiveness of the heavy-ion component, with a smaller component due to uncertainties in transport physics and dosimetry. These same uncertainties are also critical in the therapy setting. PMID:23032883

Zeitlin, Cary

2012-11-01

363

Multi-Color Single Particle Tracking with Quantum Dots

Quantum dots (QDs) have long promised to revolutionize fluorescence detection to include even applications requiring simultaneous multi-species detection at single molecule sensitivity. Despite the early promise, the unique optical properties of QDs have not yet been fully exploited in e. g. multiplex single molecule sensitivity applications such as single particle tracking (SPT). In order to fully optimize single molecule multiplex application with QDs, we have in this work performed a comprehensive quantitative investigation of the fluorescence intensities, fluorescence intensity fluctuations, and hydrodynamic radii of eight types of commercially available water soluble QDs. In this study, we show that the fluorescence intensity of CdSe core QDs increases as the emission of the QDs shifts towards the red but that hybrid CdSe/CdTe core QDs are less bright than the furthest red-shifted CdSe QDs. We further show that there is only a small size advantage in using blue-shifted QDs in biological applications because of the additional size of the water-stabilizing surface coat. Extending previous work, we finally also show that parallel four color multicolor (MC)-SPT with QDs is possible at an image acquisition rate of at least 25 Hz. We demonstrate the technique by measuring the lateral dynamics of a lipid, biotin-cap-DPPE, in the cellular plasma membrane of live cells using four different colors of QDs; QD565, QD605, QD655, and QD705 as labels.

Arnspang, Eva C.; Brewer, Jonathan R.; Lagerholm, B. Christoffer

2012-01-01

364

An increasing entropy for a free quantum particle

NASA Astrophysics Data System (ADS)

For a quantum-mechanical particle without interaction, a linear manifold of states is identified that has a preferred time direction pointing to the future. States with the broken time-reversal symmetry are singled out by their behavior under dilations. At positive times such states can be described in terms of a density operator with the property that the trace of its square decreases as the time increases. This density operator determines an entropy that approaches its least upper bound when the time tends to infinity. The expectation value of the dilation operator was negative in the distant past and will be positive in the remote future. This is the irreversible aspect of the time evolution that causes the entropy to increase, although there is no approach to equilibrium. The density operator with increasing entropy is obtained from the usual density operator by an invertible transformation that is compared with the ?-transformation in the Prigogine theory of irreversible behavior in K-systems and large Hamiltonian systems with many resonances.

van Winter, Clasine

1998-07-01

365

Liquid xenon detectors for particle physics and astrophysics

NASA Astrophysics Data System (ADS)

This article reviews the progress made over the last 20years in the development and applications of liquid xenon detectors in particle physics, astrophysics, and medical imaging experiments. A summary of the fundamental properties of liquid xenon as radiation detection medium, in light of the most current theoretical and experimental information is first provided. After an introduction of the different type of liquid xenon detectors, a review of past, current, and future experiments using liquid xenon to search for rare processes and to image radiation in space and in medicine is given. Each application is introduced with a survey of the underlying scientific motivation and experimental requirements before reviewing the basic characteristics and expected performance of each experiment. Within this decade it appears likely that large volume liquid xenon detectors operated in different modes will contribute to answering some of the most fundamental questions in particle physics, astrophysics, and cosmology, fulfilling the most demanding detection challenges. From detectors based solely on liquid xenon (LXe) scintillation, such as in the MEG experiment for the search of the rare “ ??e? ” decay, currently the largest liquid xenon detector in operation, and in the XMASS experiment for dark matter detection, to the class of time projection chambers which exploit both scintillation and ionization of LXe, such as in the XENON dark matter search experiment and in the Enriched Xenon Observatory for neutrinoless double beta decay, unrivaled performance and important contributions to physics in the next few years are anticipated.

Aprile, E.; Doke, T.

2010-07-01

366

Liquid xenon detectors for particle physics and astrophysics

This article reviews the progress made over the last 20 years in the development and applications of liquid xenon detectors in particle physics, astrophysics, and medical imaging experiments. A summary of the fundamental properties of liquid xenon as radiation detection medium, in light of the most current theoretical and experimental information is first provided. After an introduction of the different type of liquid xenon detectors, a review of past, current, and future experiments using liquid xenon to search for rare processes and to image radiation in space and in medicine is given. Each application is introduced with a survey of the underlying scientific motivation and experimental requirements before reviewing the basic characteristics and expected performance of each experiment. Within this decade it appears likely that large volume liquid xenon detectors operated in different modes will contribute to answering some of the most fundamental questions in particle physics, astrophysics, and cosmology, fulfilling the most demanding detection challenges. From detectors based solely on liquid xenon (LXe) scintillation, such as in the MEG experiment for the search of the rare ''{mu}{yields}e{gamma}'' decay, currently the largest liquid xenon detector in operation, and in the XMASS experiment for dark matter detection, to the class of time projection chambers which exploit both scintillation and ionization of LXe, such as in the XENON dark matter search experiment and in the Enriched Xenon Observatory for neutrinoless double beta decay, unrivaled performance and important contributions to physics in the next few years are anticipated.

Aprile, E.; Doke, T. [Department of Physics, Columbia University, New York, New York 10027 (United States); Advanced Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555 (Japan)

2010-07-15

367

IViPP: A Tool for Visualization in Particle Physics

NASA Astrophysics Data System (ADS)

Experiments and simulations in physics generate a lot of data; visualization is helpful to prepare that data for analysis. IViPP (Interactive Visualizations in Particle Physics) is an interactive computer program that visualizes results of particle physics simulations or experiments. IViPP can handle data from different simulators, such as SRIM or MCNP. It can display relevant geometry and measured scalar data; it can do simple selection from the visualized data. In order to be an effective visualization tool, IViPP must have a software architecture that can flexibly adapt to new data sources and display styles. It must be able to display complicated geometry and measured data with a high dynamic range. We therefore organize it in a highly modular structure, we develop libraries to describe geometry algorithmically, use rendering algorithms running on the powerful GPU to display 3-D geometry at interactive rates, and we represent scalar values in a visual form of scientific notation that shows both mantissa and exponent.

Tran, Hieu; Skiba, Elizabeth; Baldwin, Doug

2011-11-01

368

22nd SLAC Summer Institute on Particle Physics: Particle physics, astrophysics and cosmology

NASA Astrophysics Data System (ADS)

The seven-day school portion of the Institute revolved around the question of dark matter: where is it and what is it? Reviews were given of microlensing searches for baryonic dark matter, of dark matter candidates in the form of neutrinos and exotic particles, and of low-noise detection techniques used to search for the latter. The history of the universe, from the Big Bang to the role of dark matter in the formation of large-scale structure, was also covered. Other lecture series described the astrophysics that might be done with x-ray timing experiments and through the detection of gravitational radiation. As in past years, the lectures each morning were followed by stimulating afternoon discussion sessions, in which students could pursue with the lecturers the topics that most interested them. The Institute concluded with a three-day topical conference covering recent developments in theory and experiment. Highlights from the astrophysical and cosmological arenas included observations of anisotropy in the cosmic microwave background, and of the mysterious gamma-ray bursters. From terrestrial accelerators came tantalizing hints of the top quark and marked improvements in precision electroweak measurements, among many other results. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

Chan, J.; Deporcel, L.

369

Highest energy particle physics with the Pierre Auger Observatory

NASA Astrophysics Data System (ADS)

Astroparticles offer a new path for research in the field of particle physics, allowing investigations at energies above those accesible with accelerators. Ultra-high energy cosmic rays can be studied via the observation of the showers they generate in the atmosphere. The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays, combining two complementary measurement techniques used by previous experiments, to get the best possible measurements of these air showers. Shower observations enable one to not only estimate the energy, direction and most probable mass of the primary cosmic particles but also to obtain some information about the properties of their hadronic interactions. Results that are most relevant in the context of determining hadronic interaction characteristics at ultra-high energies will be presented.

Mariazzi, Analisa

2014-05-01

370

Computational particle physics for event generators and data analysis

NASA Astrophysics Data System (ADS)

High-energy physics data analysis relies heavily on the comparison between experimental and simulated data as stressed lately by the Higgs search at LHC and the recent identification of a Higgs-like new boson. The first link in the full simulation chain is the event generation both for background and for expected signals. Nowadays event generators are based on the automatic computation of matrix element or amplitude for each process of interest. Moreover, recent analysis techniques based on the matrix element likelihood method assign probabilities for every event to belong to any of a given set of possible processes. This method originally used for the top mass measurement, although computing intensive, has shown its efficiency at LHC to extract the new boson signal from the background. Serving both needs, the automatic calculation of matrix element is therefore more than ever of prime importance for particle physics. Initiated in the 80's, the techniques have matured for the lowest order calculations (tree-level), but become complex and CPU time consuming when higher order calculations involving loop diagrams are necessary like for QCD processes at LHC. New calculation techniques for next-to-leading order (NLO) have surfaced making possible the generation of processes with many final state particles (up to 6). If NLO calculations are in many cases under control, although not yet fully automatic, even higher precision calculations involving processes at 2-loops or more remain a big challenge. After a short introduction to particle physics and to the related theoretical framework, we will review some of the computing techniques that have been developed to make these calculations automatic. The main available packages and some of the most important applications for simulation and data analysis, in particular at LHC will also be summarized (see CCP2012 slides [1]).

Perret-Gallix, Denis

2013-08-01

371

REVIEWS OF TOPICAL PROBLEMS: Hadron clusters and half-dressed particles in quantum field theory

NASA Astrophysics Data System (ADS)

Accelerator experiments show that multiple production of hadrons in high-energy collisions of particles involves the formation of unstable intermediate entities, which subsequently decay into the final hadrons. These entities are apparently not only the comparatively light resonances with which we are already familiar but also heavy nonresonant clusters (with a mass above 2-5 GeV). The cluster concept was introduced previously in cosmic-ray physics, under the name "fireballs". To determine what these clusters are from the standpoint of quantum field theory, a detailed and thorough analysis is made of some analogous processes in quantum electrodynamics which are amenable to calculation. The QED analogs of the nonresonant clusters are "half-dressed" electrons and heavy photons. The half-dressed electrons decay into photons and electrons and are completely observable entities, whose interaction properties distinguish them from dressed electrons. In other words, the nonresonant particles are generally off-shell particles (the excursion from the mass shell is in the timelike direction). The assumption that hadron clusters are only resonances would be equivalent to a very specialized assumption regarding the nature of the spectral function of the hadron propagator; it would be different from that in electrodynamics, where the spectral function can be calculated. Nonresonant hadron clusters thus fit naturally into hadron field theory and are nonequilibrium hadrons far from the mass shell in the timelike direction. (In certain cases, their structural distortion is of the same nature as that of a half-dressed electron, so that this term can be conventionally applied to them as well.

Fe?nberg, E. L.

1980-10-01

372

The theoretical apparatus of semantic realism: A new language for classical and quantum physics

The standard interpretation of quantum physics (QP) and some recent generalizations of this theory rest on the adoption of a rerificationist theory of truth and meaning, while most proposals for modifying and interpreting QP in a realistic way attribute an ontological status to theoretical physical entities (ontological realism). Both terms of this dichotomy are criticizable, and many quantum paradoxes can

Claudio Garola; Luigi Solombrino

1996-01-01

373

Theorems on estimating perturbative coefficients in quantum field theory and statistical physics

We present rigorous proofs for several theorems on using Pade approximants to estimate coefficients in perturbative quantum field theory and statistical physics. As a result, we find new trigonometric and other identities where the estimates based on this approach are exact. We discuss hypergeometric functions, as well as series from both perturbative quantum field theory and statistical physics.

Samuel, M.A. [Oklahoma State Univ., Stillwater, OK (United States)]|[Stanford Univ., CA (United States); Druger, S.D. [Northwestern Univ., Evanston, IL (United States)

1995-06-01

374

Theorems on Estimating Perturbative Coefficients in Quantum Field Theory and Statistical Physics

The authors present rigorous proofs for several theorems on using Pade approximants to estimate coefficients in Perturbative Quantum Field Theory and Statistical Physics. As a result, they find new trigonometric and other identities where the estimates based on this approach are exact. They discuss hypergeometric functions, as well as series from both Perturbative Quantum Field Theory and Statistical Physics.

Samuel, Mark

2003-06-25

375

Introduction to the Geometrical Standard Model of Particle Physics

NASA Astrophysics Data System (ADS)

The Geometrical Standard Model (GSM) of Particle Physics is founded on the principles of a new geometrical tool, Rate Change Graph Technology (RCGT). RCGT was specifically designed to model the complexities of universal concepts. The GSM modeling tool parallels the SM with its own Rate Change Graph Mechanics yet is able to duplicate the SM structure and expand on concepts beyond the SM. RCGT uses a new methodology called geometrical intersections to increase the data available for computing and provides valuable clues as to the missing processes in current scientific practices. Forget about size and value, think geometry and in doing so peel back the layers of the physical world to see for the first time a geometrical universe.

Strickland, Ken

2011-11-01

376

Electron-hole quantum physics in ZnO

NASA Astrophysics Data System (ADS)

This dissertation describes several new aspects of the quantum physics of electrons and holes in zinc oxide (ZnO), including a few possible applications. Zinc oxide is a II-VI semiconductor with a direct band gap in the ultraviolet. Experimental and theoretical studies have been performed, both on bulk ZnO and on ZnO nanowires. Chapter 2 presents a new technique for an ultrafast all-optical shutter, based on two-photon absorption in a ZnO crystal. This shutter can be used for luminescence experiments requiring extremely high time-resolution. Chapter 3 describes a time-resolved study on the electron-hole many-body effects in highly excited ZnO at room temperature, in particular band-filling, band-gap renormalization, and the disappearance of the exciton resonance due to screening. In Chapter 4, the quantum many-body theory developed and experimentally verified in Chapter 3, is used to explain laser action in ZnO nanowires, and compared with experimental results. In contrast to current opinion, the results indicate that excitons are not involved in the laser action. The measured emission wavelength, the laser threshold, and the spectral distance between the laser modes are shown to be excellently explained by our quantum many-body theory. Multiple scattering of light in a forest of nanowires can be employed to enhance light absorption in solar cells. Optimization of this technique requires better understanding of light diffusion in such a nanowire forest. In Chapter 5 we demonstrate a method, based on two-photon absorption, to directly measure the residence time of light in a nanowire forest, and we show that scanning electron microscope (SEM) images can be used to predict the photon mean free path. In Chapter 6 we present a new ultrafast all-optical transistor, consisting of a forest of ZnO nanowires. After excitation, laser action in this forest causes rapid recombination of the majority of the electrons and holes, limiting the amplification to 1.2 picoseconds only . This ultrafast ultraviolet transistor may have applications in all-optical computing and in pump-probe experiments. Finally, Chapter 7 presents our discovery of preformed electron-hole Cooper pairs. A ZnO crystal has been highly excited via three-photon absorption at cryogenic temperatures. A new peak appears in the measured emission spectra when the crystal is cooled below a certain temperature, and also when it is excited above a certain density. Comparison with light amplification spectra, calculated from quantum many-body theory, demonstrates that this new peak is due to amplified spontaneous emission (ASE) from preformed electron-hole Cooper pairs.

Versteegh, M. A. M.

2011-09-01

377

GENERAL: Schemes for Splitting Quantum Information with Four-Particle Genuine Entangled States

We propose two schemes for splitting single- and two-qubit states by using four-particle genuine entangled state as the quantum channel. After the sender performs Bell-basis (or three-partite GHZ- basis) measurements on her particles, and the cooperators operate single-particle measurements on their particles, the state receiver can reconstruct the original state of the sender by applying the appropriate unitary operation. In

You-Bang Zhan; Qun-Yong Zhang; Yu-Wu Wang

2010-01-01

378

Quantum theory of magnetic quadrupole lenses for spin-1\\/2 particles

General guidelines for constructing a quantum theory of charged-particle beam\\u000aoptics starting ab initio from the basic equations of quantum mechanics,\\u000aappropriate to the situation under study. In the context of spin-1\\/2 particles,\\u000athese guidelines are used starting with the Dirac equation. The spinor theory\\u000ajust constructed is used to obtain the transfer maps for normal and skew\\u000amagnetic quadrupoles

Sameen Ahmed Khan; Galileo Galilei

1998-01-01

379

NASA Astrophysics Data System (ADS)

In this Letter, we analytically explore the effect of the Hawking radiation on the quantum correlation and Bell non-locality for Dirac particles in the background of Schwarzschild black hole. It is shown that when the Hawking effect is almost nonexistent, corresponding to the case of an almost extreme black hole, the quantum properties of physically accessible state are the same for the initial situation. For finite Hawking temperature T, the accessible quantum correlation monotonously decreases along with increasing T owing to the thermal fields generated by the Hawking effect, and the accessible quantum non-locality will be disappeared when the Hawking temperature is more than a fixed value which increases with the parameter r of Werner state growing. Then we analyze the redistribution of quantum correlation, and find that for the case of the Hawking temperature being infinite, corresponding to the case of the black hole evaporating completely, the quantum correlation of physically accessible state is equal to the one of the inaccessible states. Moreover, due to the Pauli exclusion principle and the differences between Fermi-Dirac and Bose-Einstein statistics, for the Dirac fields the accessible classical correlation decreases with increase of the Hawking temperature, which is different for the scalar fields. For Bell non-locality, we also find that the quantum non-locality is always extinct for physically inaccessible states, and the strength of the non-locality decreases with enlarging intensity of Hawking effect when the non-locality is existent in physically accessible state.

Xu, Shuai; Song, Xue-ke; Shi, Jia-dong; Ye, Liu

2014-06-01

380

FOREWORD: Corfu Summer Institute on Elementary Particle Physics (CORFU2005)

NASA Astrophysics Data System (ADS)

These are the Proceedings of the Corfu Summer Institute on Elementary Particle Physics (CORFU2005) (http://corfu2005.physics.uoi.gr), which took place in Corfu, Greece from 4 - 26 September 2005. The Corfu Summer Institute has a very long, interesting and successful history, some elements of which can be found in http://www.corfu-summer-institute.gr. In short, the Corfu Meeting started as a Summer School on Elementary Particle Physics (EPP) mostly for Greek graduate students in 1982 and has developed into a leading international Summer Institute in the field of EPP, both experimental and theoretical, providing in addition a very rich outreach programme to teachers and school students. The CORFU2005 Summer Institute on EPP, although based on the general format that has been developed and established in the Corfu Meetings during previous years, is characterized by the fact that it was a full realization of a new idea, which started experimentally in the previous two Corfu Meetings. The successful new ingredient was that three European Marie Curie Research Training Networks decided to hold their Workshops in Corfu during September 2005 and they managed to coordinate the educational part of their meetings to a huge Summer School called `The 8th Hellenic School on Elementary Particle Physics' (4 - 11 September). The European Networks which joined forces to materialize this project and the corresponding dates of their own Workshops are:

Anagnostopoulos, Konstantinos; Antoniadis, Ignatios; Fanourakis, George; Kehagias, Alexandros; Savoy-Navarro, Aurore; Wess, Julius; Zoupanos, George

2006-12-01

381

``Who Thinks Abstractly?'': Quantum Theory and the Architecture of Physical Concepts

NASA Astrophysics Data System (ADS)

Beginning with its introduction by W. Heisenberg, quantum mechanics was often seen as an overly abstract theory, mathematically and physically, vis-à-vis classical physics or relativity. This perception was amplified by the fact that, while the quantum-mechanical formalism provided effective predictive algorithms for the probabilistic predictions concerning quantum experiments, it appeared unable to describe, even by way idealization, quantum processes themselves in space and time, in the way classical mechanics or relativity did. The aim of the present paper is to reconsider the nature of mathematical and physical abstraction in modern physics by offering an analysis of the concept of ``physical fact'' and of the concept of ``physical concept,'' in part by following G. W. F. Hegel's and G. Deleuze's arguments concerning the nature of conceptual thinking. In classical physics, relativity, and quantum physics alike, I argue, physical concepts are defined by the following main features--1) their multi-component multiplicity; 2) their essential relations to problems; 3) and the interactions between physical, mathematical, and philosophical components within each concept. It is the particular character of these interactions in quantum mechanics, as defined by its essentially predictive (rather than descriptive) nature, that distinguishes it from classical physics and relativity.

Plotnitsky, Arkady

2011-03-01

382

Undergraduate participation in the ACU particle physics program

Undergraduate students from ACU have played important roles in particle physics research since 1979. Most of the involvement has centered around the pion-nucleon program at the Clinton P. Anderson Meson Factory (LAMPF) at Los Alamos, NM. Other laboratories where students have participated have been Brookhaven, Fermilab, and the Petersburg Nuclear Physics Institute (Russia). The world`s first complete sets of data in pion-nucleon scattering in the resonance region have been obtained. These measurements consisted of differential cross sections and analyzing power measurements for {pi}{sup +}p {yields} {pi}{sup +}p, {pi}{sup {minus}}p {yields}{pi}{sup 0}n and the spin rotation parameters (A & R) for the first two reactions. Recent measurements have concentrated on detecting neutral-particle final states in pion-nucleon interactions, including measurements at the world`s lowest energies for {pi}{sup {minus}}p {yields} {pi}{sup 0}n (charge exchange scattering) and eta production ({pi}{sup {minus}}p {yields} {eta}n). An overview of the experimental program and significant results will be presented. Insights will be discussed on the involvement of undergraduates in this type of research, based on fifteen years of experience.

Sadler, M.

1995-04-01

383

[Investigations in dynamics of gauge theories in theoretical particle physics

The major theme of the theoretical physics research conducted under DOE support over the past several years has been within the rubric of the standard model, and concerned the interplay between symmetries and dynamics. The research was thus carried out mostly in the context of gauge field theories, and usually in the presence of chiral fermions. Dynamical symmetry breaking was examined both from the point of view of perturbation theory, as well as from non-perturbative techniques associated with certain characteristic features of specific theories. Among the topics of research were: the implications of abelian and non-abelian anomalies on the spectrum and possible dynamical symmetry breaking in any theory, topological and conformal properties of quantum fields in two and higher dimensions, the breaking of global chiral symmetries by vector-like gauge theories such as QCD, the phenomenological implications of a strongly interacting Higgs sector in the standard model, and the application of soliton ideas to the physics to be explored at the SSC.

Not Available

1993-02-01

384

The Franck-Condon Principle and Condon Parabolas in a Physical Chemistry or Quantum Physics Course

NASA Astrophysics Data System (ADS)

A discussion of Franck-Condon factors and the associated Condon parabola suitable for inclusion in a junior- or senior-level physical chemistry or quantum physics course is presented. The Condon parabola is a convenient means of displaying and visualizing the values of Franck-Condon factors for transitions between two electronic states of a diatomic molecule. In the Condon parabola, Franck-Condon factors are displayed using a contour format to better bring out their parabola-like distribution and the associated interference pattern corresponding to transition intensities. A description of the Condon parabola and Franck-Condon factors for a model in which harmonic oscillators are used to represent the electronic states of a diatomic molecule is given. The effects of varying the equilibrium internuclear separations of the states and the state force constants are illustrated. A Condon parabola for a real diatomic molecule, diatomic potassium, is also shown, and similarities to the harmonic oscillator model are discussed.

Standard, Jean M.; Clark, Brian K.

1999-10-01

385

Two-particle quantum interference in tunnel-coupled optical tweezers.

The quantum statistics of atoms is typically observed in the behavior of an ensemble via macroscopic observables. However, quantum statistics modifies the behavior of even two particles. Here, we demonstrate near-complete control over all the internal and external degrees of freedom of two laser-cooled (87)Rb atoms trapped in two optical tweezers. This controllability allows us to observe signatures of indistinguishability via two-particle interference. Our work establishes laser-cooled atoms in optical tweezers as a promising route to bottom-up engineering of scalable, low-entropy quantum systems. PMID:24968938

Kaufman, A M; Lester, B J; Reynolds, C M; Wall, M L; Foss-Feig, M; Hazzard, K R A; Rey, A M; Regal, C A

2014-07-18

386

Molecular Physics and Chemistry Applications of Quantum Monte Carlo.

National Technical Information Service (NTIS)

We discuss recent work with the diffusion quantum Monte Carlo (QMC) method in its application to molecular systems. The formal correspondence of the imaginary time Schroedinger equation to a diffusion equation allows one to calculate quantum mechanical ex...

P. J. Reynolds R. N. Barnett B. L. Hammond W. A. Lester

1985-01-01

387

Quantum Zeno Effect and Parametric Resonance in Mesoscopic Physics

NASA Astrophysics Data System (ADS)

As a realization of the quantum Zeno effect, we consider electron tunneling between two quantum dots with one of the dots coupled to a quantum point contact detector. The coupling leads to decoherence and to the suppression of tunneling. When the detector is driven with an ac voltage, a parametric resonance occurs which strongly counteracts decoherence. We propose a novel experiment with which it is possible to observe both the quantum Zeno effect and the parametric resonance in electric transport.

Hackenbroich, G.; Rosenow, B.; Weidenmüller, H. A.

1998-12-01

388

Model for the motion of a particle in a quantum background

We are studying the dynamics of a one-dimensional field in a noncommutative Euclidean space. The noncommutative space we consider is the one that emerges in the context of three-dimensional Euclidean quantum gravity: it is a deformation of the classical Euclidean space E{sup 3} and the Planck length l{sub P} plays the role of the deformation parameter. The field is interpreted as a particle which evolves in a quantum background. When the dynamics of the particle are linear, the resulting motion is similar to the standard motion in the classical space E{sup 3}. However, nonlinear dynamics on the noncommutative space are different from the corresponding nonlinear dynamics on the classical space. These discrepancies are interpreted as ''quantum gravity'' effects. Finally, we propose a background independent description of the propagation of the particle in the quantum geometry.

Noui, Karim [Laboratoire de Mathematiques et de PhysiqueTheorique, UMR/CNRS 6083, Federation Denis Poisson, Faculte des Sciences et Techniques, Parc de Grandmont, 37200 Tours (France)

2008-11-15

389

NASA Astrophysics Data System (ADS)

Recently, we developed a method for calculating the lifetime of a particle inside a magnetic trap with respect to spin flips, as a first step in our efforts to understand the quantum mechanics of magnetic traps. The one-dimensional toy model that was used in this study was physically unrealistic because the magnetic field was not curl free. Here, we study, both classically and quantum mechanically, the problem of a neutral particle with spin S, mass m, and magnetic moment ?, moving in three dimensions in an inhomogeneous magnetic field corresponding to traps of the Ioffe-Pritchard ``clover-leaf'' and ``baseball'' type. Defining by ?p, ?z, and ?r the precessional, the axial, and the lateral vibrational frequencies, respectively, of the particle in the adiabatic potential Veff =?|B|, we find classically the region in the (?r/?p)-(?z/?p) plane where the particle is trapped. Quantum mechanically, we study the problem of a spin-one particle in the same field. Treating ?r/?p and ?z/?p as small parameters for the perturbation from the adiabatic Hamiltonian, we derive a closed-form expression for the transition rate 1/Tesc of the particle from its trapped ground state. In the extreme cases, the expression for 1/Tesc reduces to 4??r exp(-2?p/?r) for ?p>>?r>>?z, to 82??p?i exp(-2?p/?i) for ?p>>?r=?z??i and to ?/2 ?r(?z/?p)3/2exp(-2?p/?z) for ?p>>?z>>?r.

Gov, S.; Shtrikman, S.; Thomas, H.

2000-04-01

390

In most widely discussed discrete time quantum walk model, after every unitary shift operator, the particle evolves into the superposition of position space and settles down in one of its basis states, loosing entanglement in the coin space in the new position. The Hadamard operation is applied to let the particle to evolve into the superposition in the coin space

C. M. Chandrashekar

2006-01-01

391

A global search strategy of quantum-behaved particle swarm optimization

Based on the quantum-behaved particle swarm optimization (QPSO) algorithm, we formulate the philosophy of QPSO and introduce a so-called mainstream thought of the population to evaluate the search scope of a particle and thus propose a novel parameter control method of QPSO. After that, we test the revised QPSO algorithm on several benchmark functions and the experiment results show its

Jun Sun; Wenbo Xu; Bin Feng

2004-01-01

392

A Complete Physical Germanium-on-Silicon Quantum Dot Self-Assembly Process

Achieving quantum dot self-assembly at precise pre-defined locations is of vital interest. In this work, a novel physical method for producing germanium quantum dots on silicon using nanoindentation to pre-define nucleation sites is described. Self-assembly of ordered ~10?nm height germanium quantum dot arrays on silicon substrates is achieved. Due to the inherent simplicity and elegance of the proposed method, the results describe an attractive technique to manufacture semiconductor quantum dot structures for future quantum electronic and photonic applications.

Alkhatib, Amro; Nayfeh, Ammar

2013-01-01

393

A Complete Physical Germanium-on-Silicon Quantum Dot Self-Assembly Process

NASA Astrophysics Data System (ADS)

Achieving quantum dot self-assembly at precise pre-defined locations is of vital interest. In this work, a novel physical method for producing germanium quantum dots on silicon using nanoindentation to pre-define nucleation sites is described. Self-assembly of ordered ~10 nm height germanium quantum dot arrays on silicon substrates is achieved. Due to the inherent simplicity and elegance of the proposed method, the results describe an attractive technique to manufacture semiconductor quantum dot structures for future quantum electronic and photonic applications.

Alkhatib, Amro; Nayfeh, Ammar

2013-06-01

394

Dynamical coherent states and physical solutions of quantum cosmological bounces

A new model is studied which describes the quantum behavior of transitions through an isotropic quantum cosmological bounce in loop quantum cosmology sourced by a free and massless scalar field. As an exactly solvable model even at the quantum level, it illustrates properties of dynamical coherent states and provides the basis for a systematic perturbation theory of loop quantum gravity. The detailed analysis is remarkably different from what is known for harmonic oscillator coherent states. Results are evaluated with regard to their implications in cosmology, including a demonstration that in general quantum fluctuations before and after the bounce are unrelated. Thus, even within this solvable model the condition of classicality at late times does not imply classicality at early times before the bounce without further assumptions. Nevertheless, the quantum state does evolve deterministically through the bounce.

Bojowald, Martin [Institute for Gravitational Physics and Geometry, Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802 (United States) and Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)

2007-06-15

395

Energy related applications of elementary particle physics. Final report

The current research position is summarized, and what could be done in the future to clarify issues which were opened up by the research is indicated. Following on the discussion of the viability of catalyzed fusion, there is presented along with the key experimental results, a short account of the physics surrounding the subject. This is followed by a discussion of key research topics addressed. In consequence of the progress made, it appears that the feasibility of a small-scale fusion based on catalyzed reactions rests on either the remote chance that a yet undiscovered ultraheavy negatively charged elementary particle exists in Nature, or on the possible technical realization of a system based on muon-catalyzed fusion (MuCF) in high-density degenerate hydrogen plasma (density 1000 LHD, temperature O(100 eV)). The lattter is considered to have practical promise.

Rafelski, J.

1991-08-31

396

Quantum cellular automata: the physics of computing with arrays of quantum dot molecules

We discuss the fundamental limits of computing using a new paradigm for quantum computation, cellular automata composed of arrays of coulombically coupled quantum dot molecules, which we term quantum cellular automata (QCA). Any logical or arithmetic operation can be performed in this scheme. QCA's provide a valuable concrete example of quantum computation in which a number of fundamental issues come

C. S. Lent; P. D. Tougaw; W. Porod

1994-01-01

397

NASA Astrophysics Data System (ADS)

This is a call for contributions to a special issue of Journal of Physics A: Mathematical and Theoretical dedicated to quantum physics with non-Hermitian operators. The main motivation behind this special issue is to gather together recent results, developments and open problems in this rapidly evolving field of research in a single comprehensive volume. We expect that such a special issue will become a valuable reference for the broad scientific community working in mathematical and theoretical physics. The issue will be open to all contributions containing new results on non-Hermitian theories which are explicitly PT-symmetric and/or pseudo-Hermitian or quasi-Hermitian. The main novelties in the past years in this area have been many experimental observations, realizations, and applications of PT symmetric Hamiltonians in optics and microwave cavities. We especially invite contributions on the theoretical interpretations of these recent PT-symmetric experiments and on theoretical proposals for new experiments. Editorial policy The Guest Editors for this issue are Carl Bender, Andreas Fring, Uwe Guenther and Hugh Jones. The areas and topics for this issue include, but are not limited to: spectral problems novel properties of complex optical potentials PT-symmetry related threshold lasers and spectral singularities construction of metric operators scattering theory supersymmetric theories Lie algebraic and Krein-space methods random matrix models classical and semi-classical models exceptional points in model systems operator theoretic approaches microwave cavities aspects of integrability and exact solvability field theories with indefinite metric All contributions will be refereed and processed according to the usual procedure of the journal. Papers should report original and significant research that has not already been published. Guidelines for preparation of contributions The deadline for contributed papers will be 31 March 2012. This deadline will allow the special issue to appear before the end of November 2012. There is a nominal page limit of 15 printed pages per contribution (invited review papers can be longer). For papers exceeding this limit, the Guest Editors reserve the right to request a reduction in length. Further advice on publishing your work in Journal of Physics A: Mathematical and Theoretical may be found at iopscience.iop.org/jphysa. Contributions to the special issue should be submitted by web upload via authors.iop.org, or by email to jphysa@iop.org, quoting 'JPhysA Special issue on quantum physics with non-Hermitian operators'. Submissions should ideally be in standard LaTeX form. Please see the website for further information on electronic submissions. All contributions should be accompanied by a read-me file or covering letter giving the postal and e-mail addresses for correspondence. The Publishing Office should be notified of any subsequent change of address. The special issue will be published in the print and online versions of the journal.

Bender, Carl M.; Fring, Andreas; Guenther, Uwe; Jones, Hugh F.

2012-01-01

398

NASA Astrophysics Data System (ADS)

This is a call for contributions to a special issue of Journal of Physics A: Mathematical and Theoretical dedicated to quantum physics with non-Hermitian operators. The main motivation behind this special issue is to gather together recent results, developments and open problems in this rapidly evolving field of research in a single comprehensive volume. We expect that such a special issue will become a valuable reference for the broad scientific community working in mathematical and theoretical physics. The issue will be open to all contributions containing new results on non-Hermitian theories which are explicitly PT-symmetric and/or pseudo-Hermitian or quasi-Hermitian. The main novelties in the past years in this area have been many experimental observations, realizations, and applications of PT symmetric Hamiltonians in optics and microwave cavities. We especially invite contributions on the theoretical interpretations of these recent PT-symmetric experiments and on theoretical proposals for new experiments. Editorial policy The Guest Editors for this issue are Carl Bender, Andreas Fring, Uwe Guenther and Hugh Jones. The areas and topics for this issue include, but are not limited to: spectral problems novel properties of complex optical potentials PT-symmetry related threshold lasers and spectral singularities construction of metric operators scattering theory supersymmetric theories Lie algebraic and Krein-space methods random matrix models classical and semi-classical models exceptional points in model systems operator theoretic approaches microwave cavities aspects of integrability and exact solvability field theories with indefinite metric All contributions will be refereed and processed according to the usual procedure of the journal. Papers should report original and significant research that has not already been published. Guidelines for preparation of contributions The deadline for contributed papers will be 31 March 2012. This deadline will allow the special issue to appear before the end of November 2012. There is a nominal page limit of 15 printed pages per contribution (invited review papers can be longer). For papers exceeding this limit, the Guest Editors reserve the right to request a reduction in length. Further advice on publishing your work in Journal of Physics A: Mathematical and Theoretical may be found at iopscience.iop.org/jphysa. Contributions to the special issue should be submitted by web upload via authors.iop.org/, or by email to jphysa@iop.org, quoting 'JPhysA Special issue on quantum physics with non-Hermitian operators'. Submissions should ideally be in standard LaTeX form. Please see the website for further information on electronic submissions. All contributions should be accompanied by a read-me file or covering letter giving the postal and e-mail addresses for correspondence. The Publishing Office should be notified of any subsequent change of address. The special issue will be published in the print and online versions of the journal.

Bender, Carl M.; Fring, Andreas; Guenther, Uwe; Jones, Hugh F.

2012-01-01

399

European Particle Physics Masterclasses Make Students into Scientists for a Day

ERIC Educational Resources Information Center

In 2005 the European particle physics masterclasses attracted 3000 students from 18 European countries to visit one of 58 universities and education centres. The participants worked with data from real high energy particle collisions, learned about particle physics, and experienced research and education environments at European universities. In…

Johansson, K. E.; Kobel, M.; Hillebrandt, D.; Engeln, K.; Euler, M.

2007-01-01

400

Scintillating plastic optical fiber radiation detectors in high energy particle physics

We describe the application of scintillating optical fiber in instrumentation for high energy particle physics. The basic physics of the scintillation process in polymers is discussed first and then we outline the fundamentals of scintillating fiber technology. Fiber performance, optimization, and characterization measurements are given. Detector applications in the areas of particle tracking and particle energy determination are then described. 13 refs., 12 figs.

Bross, A.D.

1991-10-26

401

GENERAL: Schemes for Splitting Quantum Information with Four-Particle Genuine Entangled States

NASA Astrophysics Data System (ADS)

We propose two schemes for splitting single- and two-qubit states by using four-particle genuine entangled state as the quantum channel. After the sender performs Bell-basis (or three-partite GHZ- basis) measurements on her particles, and the cooperators operate single-particle measurements on their particles, the state receiver can reconstruct the original state of the sender by applying the appropriate unitary operation. In particular, in the scheme for splitting two-qubit state, the receiver needs to introduce an auxiliary particle and carries out a C-NOT operation.

Zhan, You-Bang; Zhang, Qun-Yong; Wang, Yu-Wu

2010-05-01

402

Quantum Tunneling Radiation of Charged Massive Particle from Reissner-Nordström-NUT Spacetime

NASA Astrophysics Data System (ADS)

By extending the semi-classical quantum tunneling method, the tunneling radiation of the massive charged particle from a charged Reissner-Nordström-NUT black hole was investigated. Difference from the uncharged mass-less particle, the geodesics of the charged massive particle tunneling from the black hole is not light-like, but determined by the phase velocity. The result shows that the tunneling rate depends on the emitted particle's energy, NUT parameter and electric charge, and takes the same functional form as uncharged particle. It also proves that the exact emission spectrum is not strictly pure thermal, but is consistent with the underlying unitary theory.

Qi, De-Jiang

2013-05-01

403

NASA Astrophysics Data System (ADS)

This work reports on the computational method for the long time propagation of the quantum channeled particles in infinite and finite harmonic interaction wells and in a realistic carbon nanotube interaction potential well. This method is based on the Chebyshev global propagation method for solving of the corresponding time dependent Schrödinger equation. For comparison, the computational method based on the Crank-Nicolson propagation method is also presented. In the case of quantum particle motion in infinite harmonic potential well, when the analytical solution of the corresponding time-dependent Schrödinger equation exists, we show that the obtained propagation method is efficient, very accurate and numerically stable. It is superior with respect to the method based on the Crank-Nicolson propagation method. A detailed study of the long time quantum particle motion in the finite harmonic interaction potential well shows that the obtained computational method based on the Chebyshev global propagation method can be successfully applied for following of the channeled quantum particle in crystals and carbon nanotubes. This is demonstrated in the case of quantum particle motion in a realistic carbon nanotube interaction potential well.

?osi?, M.; Petrovi?, S.; Neškovi?, N.

2014-07-01

404

Physical Meaning of the Optimum Measurement Process in Quantum Detection Theory

NASA Technical Reports Server (NTRS)

The optimum measurement processes are represented as the optimum detection operators in the quantum detection theory. The error probability by the optimum detection operators goes beyond the standard quantum limit automatically. However the optimum detection operators are given by pure mathematical descriptions. In order to realize a communication system overcoming the standard quantum limit, we try to give the physical meaning of the optimum detection operators.

Osaki, Masao; Kozuka, Haruhisa; Hirota, Osamu

1996-01-01

405

Physics and Applications of Quantum Dots in Photonic Crystals

\\u000a Photonic crystals provide an engineerable electromagnetic environment for controlling the interaction between light and matter.\\u000a In this chapter, we discuss quantum dot-embedded photonic crystal devices for classical and quantum information processing.\\u000a For classical applications, we discuss high-speed, low-power lasing dynamics, and carrier-induced switching in photonic crystal\\u000a cavities. For quantum information applications, we describe photonic crystals for controlling the spontaneous emission

Dirk Englund; Andrei Faraon; Ilya Fushman; Bryan Ellis; Jelena Vuckovic

2009-01-01

406

PREFACE: International Symposium "Nanoscience and Quantum Physics 2011" (nanoPHYS'11)

NASA Astrophysics Data System (ADS)

Quantum physics has developed modern views of nature for more than a century. In addition to this traditional role, quantum physics has acquired new significance in the 21st century as the field responsible for driving and supporting nanoscience research, which will have even greater importance in the future because nanoscience will be the academic foundation for new technologies. The Department of Physics, Tokyo Institute of Technology, are now conducting a "Nanoscience and Quantum Physics" project (Physics G-COE project) supported by the Global Center of Excellence Program of the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT) in order to promote research and education in these important academic fields. The International Symposium on Nanoscience and Quantum Physics, held in Tokyo, Japan, 26-28 January 2011 (nanoPHYS'11) was organized by the Physics G-COE project of the Tokyo Institute of Technology to provide an international forum for the open exchange of topical information and for stimulating discussion on novel concepts and future prospects of nanoscience and quantum physics. There were a total of 118 papers including 34 invited papers. This nanoPHYS'11 is the fourth symposium of this kind organized by the Tokyo Institute of Technology. Topics focused on in the symposium included: Category 1: Novel nanostructure (Nanowires, Nanotubes, Spin-related structure, etc) Category 2: Novel transport and electronic properties (Graphene, Topological insulators, Coherent control, etc) Category 3: Electronic and optical properties of nanostructure Category 4: Fundamental physics and new concept in quantum physics Category 5: Quantum Physics - Quantum information Category 6: Quantum Physics - Nuclear and Hadron Physics Category 7: Quantum Physics - Astrophysics, etc All the papers submitted to this issue have been reviewed under a stringent refereeing process, according to the normal rules of this Journal. The editors are grateful to all the authors, the referees, and all the individuals involved in the symposium organization, in particular, all the committee members and secretaries who helped to make this symposium so successful. The organizing committee would like to take this opportunity to thank the invited speakers, the session chairs, and all the attendees for their contribution to the symposium. Susumu Saito, Hidekazu Tanaka, Takashi Nakamura and Masaaki Nakamura, Editors Conference photograph

Saito, Susumu; Tanaka, Hidekazu; Nakamura, Takashi; Nakamura, Masaaki

2011-07-01

407

The Influence of Student Understanding of Classical Physics When Learning Quantum Mechanics

NSDL National Science Digital Library

In this conference presentation, the authors describe two examples of students having difficulty constructing an understanding of quantum mechanics due to an erroneous model of classical physics. For each example, the authors describe how a misconception of a classical concept impairs the learning of a quantum concept. This paper contains a brief discussion of how these difficulties may be addressed.

2010-04-09

408

The Influence of Student Understanding of Classical Physics When Learning Quantum Mechanics

NSDL National Science Digital Library

In this conference presentation, the authors describe two examples of students having difficulty constructing an understanding of quantum mechanics due to an erroneous model of classical physics. For each example, the authors describe how a misconception of a classical concept impairs the learning of a quantum concept. This paper contains a brief discussion of how these difficulties may be addressed.

Steinberg, Richard N.; Wittmann, Michael C.; Bao, Lei; Redish, Edward F.

2005-11-30

409

National Technical Information Service (NTIS)

An overview on the theoretic formalism and up-to-date applications in quantum condensed matter physics of the effective potential and effective hamiltonian methods is given. The main steps of their unified derivation by the pure-quantum self-consistent ha...

A. Cuccoli V. Tognetti R. Vaia P. Verrucchi

1996-01-01

410

SELF-ASSEMBLED SEMICONDUCTOR QUANTUM DOTS: Fundamental Physics and Device Applications

As a result of their fully quantized electronic states and high radiative efficiencies, self-assembled quantum dots have enabled major advances in fundamental physics studies of zero-dimensionality semiconductor systems and in a variety of novel device applications. This article reviews some of the more important recent advances, covering the study and application of both ensembles and single quantum dots. It shows

M. S. Skolnick; D. J. Mowbray

2004-01-01

411

Physics in the Twentieth Century

ERIC Educational Resources Information Center

Provides a review of the great discoveries, theoretical concepts and development of physics in the 20th century. The growth and significance of diverse fields such as quantum theory, relativity theory, atomic physics, molecular physics, the physics of the solid state, nuclear physics, astrophysics, plasma physics, and particle physics are…

Weisskopf, Victor F.

1970-01-01

412

Evolution of quantum field, particle content, and classicality in the three stage universe

NASA Astrophysics Data System (ADS)

We study the evolution of a quantum scalar field in a toy universe which has three stages of evolution, viz., (i) an early (inflationary) de Sitter phase (ii) radiation-dominated phase and (iii) late-time (cosmological constant dominated) de Sitter phase. Using the Schrödinger picture, the scalar field equations are solved separately for the three stages and matched at the transition points. The boundary conditions are chosen so that field modes in the early de Sitter evolves from the Bunch-Davies vacuum state. We determine the (time-dependent) particle content of this quantum state for the entire evolution of the universe and describe the various features both numerically and analytically. We also describe the quantum to classical transition in terms of a classicality parameter which tracks the particle creation and its effect on phase space correlation of the quantum field.

Singh, Suprit; Modak, Sujoy Kumar; Padmanabhan, T.

2013-12-01

413

Attempt of an Axiomatic Foundation of Quantum Mechanics and More General Physical Theories.

National Technical Information Service (NTIS)

By introducing certain axiomatic assumptions on the production of macroscopic effects by microscopic objects it is tried to obtain a general basic structure of physical theories. The essential features of the proposition-calculus of quantum mechanics are ...

G. Ludwig

1964-01-01

414

On estimating perturbative coefficients in quantum field theory and statistical physics

The authors present a method for estimating perturbative coefficients in quantum field theory and Statistical Physics. They are able to obtain reliable error-bars for each estimate. The results, in all cases, are excellent.

Samuel, M.A. [Oklahoma State Univ., Stillwater, OK (United States). Dept. of Physics]|[Stanford Univ., CA (United States). Stanford Linear Accelerator Center

1994-05-01

415

Research in elementary particle physics. Technical progress report, June 1, 1991--May 31, 1992

This report discusses research in the following areas of high energy physics: B meson mixing; CDF response to low energy jets; jet scaling behavior; search for pair produced leptoquarks at CDF; SSC program; quantum field theory; and neural networks. (LSP).

Kirsch, L.E.; Schnitzer, H.J.; Bensinger, J.R.; Blocker, C.A.

1992-08-01

416

Modelling Systems of Classical/Quantum Identical Particles by Focusing on Algorithms

ERIC Educational Resources Information Center

A procedure modelling ideal classical and quantum gases is discussed. The proposed approach is mainly based on the idea that modelling and algorithm analysis can provide a deeper understanding of particularly complex physical systems. Appropriate representations and physical models able to mimic possible pseudo-mechanisms of functioning and having…

Guastella, Ivan; Fazio, Claudio; Sperandeo-Mineo, Rosa Maria

2012-01-01

417

Supersymmetric many-particle quantum systems with inverse-square interactions

The development in the study of supersymmetric many-particle quantum systems with inverse-square interactions is reviewed. The main emphasis is on quantum systems with dynamical OSp(2|2) supersymmetry. Several results related to the exactly solved supersymmetric rational Calogero model, including shape invariance, equivalence to a system of free superoscillators and non-uniqueness in the construction of the Hamiltonian, are presented in some detail.

Pijush K Ghosh

2012-01-01

418

Casimir Forces and Quantum Electrodynamical Torques: Physics and Nanomechanics

This paper discusses recent developments on quantum electrodynamical (QED) phenomena, such as the Casimir effect, and their use in nanomechanics and nanotechnology in general. Casimir forces and torques arise from quantum fluctuations of vacuum or, more generally, from the zero-point energy of materials and their dependence on the boundary conditions of the electromagnetic fields. Because the latter can be tailored,

Federico Capasso; Jeremy N. Munday; Davide Iannuzzi; H. B. Chan

2007-01-01

419

Experimental particle physics at the University of Pittsburgh

During the past year Task A completed the HELIOS single and pair electron analyses and found no anomalous production or multiplicity dependence. The HELIOS electron-muon pair analysis continued in its search for lepton physics beyond the expected charm yields. Data taking began at the CMD2 detector at Novosibirsk. Measurements of the U. V. reflectivity and photomultiplier tests for the first Cerenkov counter to be used in the E865 experiment at BNL were carried out, along with the development of a general ray-tracing code. The design of the Cerenkov counter for E865 along with development of light mirror fabrication techniques were a major part of the Task A program. The principal efforts of Task B, the Fermilab program, have been the completion of the analysis of the 1987--1988 data with resulting publications, completion of the 1990--1991 data run, and the beginning of the analysis of the 1990--1991 data. In addition, the Task B group is taking a leadership role in developing a proposal to Fermilab for the upgrade of the CDF silicon vertex detector in preparation for the 1995 data run. This proposal is to be presented to the laboratory management in time for the fall Fermilab Program Advisory Committee meeting. Task C has recently submitted results of its fractionally charged particle searches, placing new upper limits on the abundance of naturally-occurring fractionally-charged particles in various materials. This group has recently been approved by the Brookhaven management for an exposure of their p-i-n diodes in a high intensity proton beam. This measurement, along with its subsequent analysis, will complete the program.

Engels, E. Jr.; Perera, U.; Shepard, P.F.; Thompson, J.A.

1992-04-01

420

QPSO-MD: A Quantum Behaved Particle Swarm Optimization for Consensus Pattern Identification

NASA Astrophysics Data System (ADS)

Particle Swarm Optimization (PSO) has been successfully applied to a wide range of fields. The recent introduction of quantum mechanics principles into PSO has given rise to a Quantum behaviour PSO (QPSO) algorithm. This paper investigates its application into motif discovery, a challenging task in bioinformatics and molecular biology. Given a set of input DNA sequences, the proposed framework acts as a search process where a population of particles is depicted by a quantum behavior. Each particle represents a set of regulatory patterns from which a consensus pattern or motif model is derived. The corresponding fitness function is related to the total number of pairwise matches between nucleotides in the input sequences. Experiment results on synthetic and real data are very promising and prove the effectiveness of the proposed framework.

Meshoul, Souham; Al-Owaisheq, Tasneem

421

Scintillating plastic optical fiber radiation detectors in high energy particle physics.

National Technical Information Service (NTIS)

We describe the application of scintillating optical fiber in instrumentation for high energy particle physics. The basic physics of the scintillation process in polymers is discussed first and then we outline the fundamentals of scintillating fiber techn...

A. D. Bross

1991-01-01

422

Physical viscosity in smoothed particle hydrodynamics simulations of galaxy clusters

NASA Astrophysics Data System (ADS)

Most hydrodynamical simulations of galaxy cluster formation carried out to date have tried to model the cosmic gas as an ideal, inviscid fluid, where only a small amount of (unwanted) numerical viscosity is present, arising from practical limitations of the numerical method employed, and with a strength that depends on numerical resolution. However, the physical viscosity of the gas in hot galaxy clusters may in fact not be negligible, suggesting that a self-consistent treatment that accounts for the internal gas friction would be more appropriate. To allow such simulations using the smoothed particle hydrodynamics (SPH) method, we derive a novel SPH formulation of the Navier-Stokes and general heat transfer equations and implement them in the GADGET-2 code. We include both shear and bulk viscosity stress tensors, as well as saturation criteria that limit viscous stress transport where appropriate. Our scheme integrates consistently into the entropy and energy conserving formulation of SPH employed by the code. Using a number of simple hydrodynamical test problems, e.g. the flow of a viscous fluid through a pipe, we demonstrate the validity of our implementation. Adopting Braginskii parametrization for the shear viscosity of hot gaseous plasmas, we then study the influence of viscosity on the interplay between AGN-inflated bubbles and the surrounding intracluster medium (ICM). We find that certain bubble properties like morphology, maximum clustercentric radius reached or survival time depend quite sensitively on the assumed level of viscosity. Interestingly, the sound waves launched into the ICM by the bubble injection are damped by physical viscosity, establishing a non-local heating process. However, we find that the associated heating is rather weak due to the overall small energy content of the sound waves. Finally, we carry out cosmological simulations of galaxy cluster formation with a viscous ICM. We find that the presence of physical viscosity induces new modes of entropy generation, including a significant production of entropy in filamentary regions perpendicular to the direction of the clusters encounter. Viscosity also modifies the dynamics of mergers and the motion of substructures through the cluster atmosphere. Substructures are generally more efficiently stripped of their gas, leading to prominent long gaseous tails behind infalling massive haloes.

Sijacki, Debora; Springel, Volker

2006-09-01

423

Studies in theoretical particle physics. Progress report, 1990--1991

This proposal focuses on research on three distinct areas of particle physics: (1) Nonperturbative QCD. I tend to continue work on analytic modelling of nonperturbative effects in the strong interactions. I have been investigating the theoretical connection between the nonrelativistic quark model and QCD. The primary motivation has been to understand the experimental observation of nonzero matrix elements involving current strange quarks in ordinary matter -- which in the quark model has no strange quark component. This has led to my present work on understanding constituent (quark model) quarks as collective excitations of QCD degrees of freedom. (2) Weak Scale Baryogenesis. A continuation of work on baryogenesis in the early universe from weak interactions. In particular, an investigation of baryogenesis occurring during the weak phase transition through anomalous baryon violating processes in the standard model of weak interactions. (3) Flavor and Compositeness. Further investigation of a new mechanism that I recently discovered for dynamical mass generation for fermions, which naturally leads to a family hierarchy structure. A discussion of recent past work is found in the next section, followed by an outline of the proposed research. A recent publication from each of these three areas is attached to this proposal.

Kaplan, D.B.

1991-07-01

424

The optical properties of core-shell CdSe-ZnS quantum dots (QDs) are characterized by complex photophysics leading to difficulties in interpreting quantitative measurements based on QD emission. By comparing the pH dependence of fluorescence of single QDs to that of an ensemble, we have been able to propose a molecular scale model of how QD surface chemical and physical processes are affected by protons and oxygen. We show that the connection between the ensemble fluorescence intensity and the single QD fluorescence properties such as dark fraction, blinking, particle brightness, and a multiexponential fluorescence lifetime decay is not trivial. The ensemble fluorescence intensity is more weakly dependent on pH than the single particle fluorescence which, together with fluorescence lifetime analysis, provided evidence that the dark fraction of QDs emits photons with low quantum efficiency and long lifetime. We uncovered two surface-dependent mechanisms that affected the fluorescence emission: an immediate physical effect of charges surrounding the QD and an irreversible chemical effect from reaction of the H(+) and O(2) with the QD shell surface. These results will have important implications for those using QD-based fluorescence lifetime imaging as well as for proper implementation of these probes for quantitative cellular imaging applications. PMID:22023370

Durisic, Nela; Godin, Antoine G; Walters, Derrel; Grütter, Peter; Wiseman, Paul W; Heyes, Colin D

2011-11-22

425

Studentsâ Conceptual Understanding of Quantum Physics in College Level Classroom Environments

NSDL National Science Digital Library

The purposes of the current study were to study the potential solutions of the common learning difficulties, insufficient teaching techniques and other significant instructional or conceptual problems encountered while teaching and learning an important branch of physical science, quantum physics (QP), at the senior or junior college year. Both quantitative and qualitative methodologies were utilized in this study. The participants included five physics faculty members with different levels of teaching experience who were teaching one of the quantum physics courses (e.g. Modern Physics, Quantum Physics, and Quantum Mechanics) and 43 senior or junior undergraduate students enrolled in their courses during fall and spring terms of 2006. The findings of this study revealed that students struggle in QP classes mainly because of (1) complex mathematical tools in QP, (2) abstract concepts and non-parallel construction of QP, (3) QP has a bad reputation that negatively affects students prior to taking it, and (4) the pace in curriculum of quantum physics courses is too fast for the students. In order to increase students' conceptualization of QP concepts, the faculty members who participated in this study suggested that: (1) more time on solving more abstract conceptual questions should be spent, (2) recitation hours for solving more numerical problems need to be dedicated, and (3) revision of curriculum is necessary.

Akarsu, Bayram

2010-01-18

426

Students' conceptual understanding of quantum physics in college level classroom environments

NASA Astrophysics Data System (ADS)

The purposes of the current study were to study the potential solutions of the common learning difficulties, insufficient teaching techniques and other significant instructional or conceptual problems encountered while teaching and learning an important branch of physical science, quantum physics (QP), at the senior or junior college year. Both quantitative and qualitative methodologies were utilized in this study. The participants included five physics faculty members with different levels of teaching experience who were teaching one of the quantum physics courses (e.g. Modern Physics, Quantum Physics, and Quantum Mechanics) and 43 senior or junior undergraduate students enrolled in their courses during fall and spring terms of 2006. The findings of this study revealed that students struggle in QP classes mainly because of (1) complex mathematical tools in QP, (2) abstract concepts and non-parallel construction of QP, (3) QP has a bad reputation that negatively affects students prior to taking it, and (4) the pace in curriculum of quantum physics courses is too fast for the students. In order to increase students' conceptualization of QP concepts, the faculty members who participated in this study suggested that: (1) more time on solving more abstract conceptual questions should be spent, (2) recitation hours for solving more numerical problems need to be dedicated, and (3) revision of curriculum is necessary.

Akarsu, Bayram

427

Quantum physics: The right ambience for a single spin

NASA Astrophysics Data System (ADS)

Long-lived single electron spins are crucial for quantum computation and for understanding spin dynamics. A remarkably long lifetime -- of the order of minutes -- has now been obtained for a solid-state system. See Letter p.242

Flatté, Michael E.

2013-11-01

428

Quantum physics: Single electrons pop out of the Fermi sea

NASA Astrophysics Data System (ADS)

The ability to control individual electrons in an electronic conductor would pave the way for novel quantum technologies. Single electrons emerging from a sea of their fellows in a nanoscale electrode can now be generated. See Letter p.659

Flindt, Christian

2013-10-01

429

Random-matrix theories in quantum physics: common concepts

We review the development of random-matrix theory (RMT) during the last fifteen years. We emphasize both the theoretical aspects, and the application of the theory to a number of fields. These comprise chaotic and disordered systems, the localization problem, many-body quantum systems, the Calogero-Sutherland model, chiral symmetry breaking in QCD, and quantum gravity in two dimensions. The review is preceded

Thomas Guhr; Hans A. Weidenmüller

1998-01-01

430

Quantum Methodologies in Beam, Fluid and Plasma Physics

NASA Astrophysics Data System (ADS)

The quantum methodologies useful for describing in a unified way several problems of nonlinear and collective dynamics of fluids, plasmas and beams are presented. In particular, the pictures given by the Madelung fluid and the Moyal-Ville-Wigner phase-space quasidistribution, including the related quantum tools such as marginal distributions for the tomographic representations, are described. Some relevant applications to soliton and modulational instability theories are presented.

Fedele, R.

2008-03-01

431

C. V. Raman and Colonial Physics: Acoustics and the Quantum

NASA Astrophysics Data System (ADS)

Presenting the social and historical context of Chandrasekhara Venkata Raman, this paper clarifies the nature and development of his work in early twentieth-century colonial India. Raman's early fascination with acoustics became the basis of his later insights into the nature of the light quantum. His work on light scattering played an important role in the experimental verification of quantum mechanics. In general, Raman's worldview corrects certain Orientalist stereotypes about scientific practice in Asia.

Banerjee, Somaditya

2014-05-01

432

The Low-Energy Frontier of Particle Physics

Most embeddings of the Standard Model into a more unified theory, in particular those based on supergravity or superstrings, predict the existence of a hidden sector of particles that have only very weak interactions with visible-sector Standard Model particles. Some of these exotic particle candidates [for instance, axions, axion-like particles, and hidden U(1) gauge bosons] may be very light, with

Joerg Jaeckel; Andreas Ringwald

2010-01-01

433

Did you mean: third law general quantum geoastrophysics formulation equilibrium combined third law micrelectrothermomechanics formulation equilibrium combined general quantum advanced derivation integral calculus formulation equilibrium combined Jenera QUANTUM MATRIX SUPER STRING FORMULATION EQUILIBRIUM COMBINED GENERAL QUANTUM TOXICOLOGY FORMULATION EQUILIBRIUM COMBINED GENERAL ADVANCED DERIVATION CALCULUS PHYSICS FORMULATION EQUILIBRIUM GENERAL QUANTUM GENERAL GEOASTROPHYSICS FORMULATION EQUILIBRIUM UNKNOWN ?

434

Multicolor quantum dot encoding for polymeric particle-based optical ion sensors.

Multicolor quantum dot-encoded polymeric microspheres are prepared with controllable and uniform doping levels that function as chemical sensors on the basis of bulk optode theory. TOP/TOPO-capped CdSe quantum dots and CdTe quantum dots capped with CdS (lambdaem = 610 and 700 nm, lambdaex = 510 nm) are blended with a THF solution of poly(methyl methacrylate-co-decyl methacrylate), poly(n-butylacrylate), or poly(vinyl chloride) plasticized with bis(2-ethylhexyl) sebacate without a need for ligand exchange. Polymeric microspheres are generated under mild, nonreactive conditions with a particle caster that breaks down a polymer stream containing the quantum dots into fine droplets by the vibration of a piezocrystal. The resulting microspheres exhibit uniform size and fluorescence emission intensities. Fluorescent bar codes are obtained by subsequent doping of two quantum dots with different colors and mass ratios into the microspheres. A linear relationship is found between the readout fluorescence ratio of the two types of nanocrystals and the mixing ratio. Quantum dot-encoded ion sensing optode microspheres are prepared by simultaneous doping of sodium ionophore X, chromoionophore II, a lipophilic tetraphenylborate cation exchanger, and TOPO-capped CdSe/CdS quantum dot as the fluorescent label. A net positive charge of the quantum dots is found to induce an anion-exchange effect on the sensor function, and therefore, an increased concentration of the lipophilic cation exchanger is required to achieve proper ion sensing properties. The modified quantum dot-labeled sodium sensing microspheres show satisfactory sodium response between 10(-4) and 0.1 M at pH 4.8, with excellent selectivity toward common interferences. The amount of the carried positive charges of the CdSe quantum dots is estimated as 2.8 mumol/g of quantum dots used in this study. PMID:17437337

Xu, Chao; Bakker, Eric

2007-05-15

435

A quantum particle (qp) in a fluid near the liquid vapor-critical point creates a volume of altered density in which it becomes localized. In previous research we have used the Path Integral Monte Carlo (PIMC) technique to investigate the properties of the qp-fluid molecule system. The path integral formulation represents the quantum particle as a closed chain of P classical

Terrence Reese; Bruce Miller

2008-01-01

436

NASA Astrophysics Data System (ADS)

This dissertation discusses a consequence of the limitation on causality originated in smallness of a quantum system. In quantum physics, disturbance due to a measurement is not negligible. Because of this fact, the time parameter t cannot be identified as a time continuum of experimenter's clock T on which observed events are recorded. Indeed, it will be shown that t represents an ensemble of time intervals on T during which a microsystem travels undisturbed. In particular t = 0 represents the ensemble of preparation events that we refer to as the ensemble of beginnings of time. This restricts t to range the positive real line only, but such a time evolution of quantum states cannot be achieved in the Hilbert space. Hence one needs the time asymmetric boundary condition in which only the semigroup time evolution is allowed. This boundary condition is characterized by the energy wave functions of quantum state (and of observables) satisfying the Hilbert transform, called in physics the dispersion relation. The time asymmetric boundary condition is formulated as a pair of Hardy rigged Hilbert spaces. They are developed to incorporate Einstein's causality. Within the framework of Hardy rigged Hilbert space, decaying states are described by Gamow vectors, and they are associated to S-matrix poles in the lower-half complex energy plane. This framework provides one a non-perturbative description of a decaying particle. From the Gamow vectors, exponential decay law of a relativistic particle is derived. Finally the neutral kaon decay experiment and the Z-boson resonance are discussed as applications.

Sato, Yoshihiro

437

Quantum theory and gravitation

Topics covered include: motivations and prospects of pregeometry; information maximized in photon polarization; roles of space-time models; an axiomatic general relativistic quantum theory; an extended quantum mechanical embedding theorem; quantum logic and quantum mappings; Bohr-Sommerfeld quantization in general relativity and other nonlinear field and particle theories; canonical quantization of gravitation theory; new directions in relativity and quantization of manifolds; the origin of mass of elementary particles; quantum interference and the gravitational field; geometrization of gauge fields; physical states and renormalized observables in quantum field theories with external gravity; quantum aspects of geometrodynamics; interpretation of quantum mechanical scattering measurements; Kaluza and Klein's five-dimensional relativity; and modern mathematical techniques in theoretical physics. (GHT)

Marlow, A.R. (ed.)

1980-01-01

438

Rotational Spectra in Service of Particle Physics - Zeeman & Hyperfine Effects

NASA Astrophysics Data System (ADS)

Motivated by the ongoing search for the parity violating effects originated by an electron electric dipole moment (e-EDM) or a nuclear anapole moment,the rotational spectra of heavy atom diatomic radicals like, e.g., ^{2}?_{1/2} PbF are studied at the unrivalled resolution offered by supersonic-jet Fourier transform microwave spectroscopy. Obtaining accurate information on such relativistically behaving systems wil be the key to provide a delicate test to the proposed theories in extension to the Standard Model of Physics. Employment of an MW method to hunt down these tiny effects, easily obscured by the linewidth inherent to other techniques, in rotational transitions is a promising approach to observe the tiny energy difference of terms that are degenerate without parity violation. Already before an experiment sensitive to parity violation, the exceptional resolution of the microwave time-domain technique can be exploited to provide accurate tests on the quantum chemical predictions that are part of the calculation of the anticipated e-EDM or anapole moment sensitivity of a given species since nuclear quadrupole and magnetic hyperfine effects in the rotational spectra are closely related. In our current experiment, transitions can be observed with 0.2 kHz accuracy for unblended lines over a range of 2 - 26.5 GHz. The observation of field dependent spectra (in magnetic fields up to 4 Gauss) allows for the determination of the two body fixed g-factors, G_{perp} and G_{allel} which can then be compared with recent theoretical values. YbF provides the current e-EDM upper limit. Although it is more sensitive to magnetic fields, the nuclear quadrupole hyperfine structure of ^{173}YbF constitutes a direct probe on the electric field gradient and thus can help characterize the critical electric field at the heavy atom nucleus. We will report on 14 GHz transitions for 3 of the less abundant even isotopologues of YbF as well as the ^{207}PbF analogue ^{171}YbF, important steps towards observing ^{173}YbF.

Mawhorter, Richard J.; Baum, Alexander L.; Glassmann, Zachary; Girodas, Benjamin; Sears, Trevor; Shafer-Ray, Neil E.; Alphei, Lukas; Grabow, Jens-Uwe

2013-06-01

439

Quantum mechanics of a spinless particle in combined coulomb and harmonic oscillator potentials

In this dissertation the quantum mechanics of a spinless particle in a combined Coulomb and harmonic oscillator potential is discussed. The particular potential considered is a 2:1 anisotropic harmonic oscillator combined with a concentric Coulomb potential. These two potentials are the two most studied potentials in mathematical physics. It is shown that the combined potential gives a Schroedinger equation that separates in a parabolic coordinate system. The energy eigenfunctions for the pure oscillator is given by the product of polynomials in the parabolic coordinates and gaussians in these same coordinates. These eigenfunctions form a complete set. The discussion of the oscillator is closed with a short discussion of the algebraic aspects of the pure oscillator problem. When the Schroedinger equation for the combined potential is separated, two equations of identical form arise. The single equation obtained is one that has received very little attention in the past. The eigenvalues of the resulting pairs of equations are found numerically. The results for these eigenvalues are presented graphically, although a method for finding them explicitly is described. Once the eigenvalues are found, the wavefunctions may then be easily found.

Stansfield, S.E.

1986-01-01

440

NASA Astrophysics Data System (ADS)

The CdSe/ZnS/CdSe core/barrier/shell nanostructure forms an electronically coupled quantum system that is a spherical analog to the quantum well superlattice. The core's brightness is enhanced via light harvesting by the shell. This material offers an opportunity to study charge transport in spherical nanoscale materials. Here, we present new results on the femtosecond dynamics of radial charge transport in these materials. With a combination of excitonic state selectivity and femtosecond time resolution, we monitor the ultrafast relaxation dynamics of either the core or the shell, having optically excited either phase. The femtosecond experiments reveal strong optical gain as well as evidence of spatially separated biexcitons, and coupling between phases. Finally, we present single dot data on the two-color blinking kinetics of these coupled quantum dot quantum shell systems.

Kambhampati, Patanjali; Sagar, D. M.; Dias, Eva; Sewall, Samuel; Cooney, Ryan; Grimes, Amy; English, Douglas

2008-03-01

441

RESEARCH NOTE FROM COLLABORATION: GridPP: development of the UK computing Grid for particle physics

The GridPP Collaboration is building a UK computing Grid for particle physics, as part of the international effort towards computing for the Large Hadron Collider. The project, funded by the UK Particle Physics and Astronomy Research Council (PPARC), began in September 2001 and completed its first phase 3 years later. GridPP is a collaboration of approximately 100 researchers in 19

P. J. W. Faulkner; L. S. Lowe; C. L. A. Tan; P. M. Watkins; D. S. Bailey; T. A. Barrass; N. H. Brook; R. J. H. Croft; M. P. Kelly; C. K. Mackay; S. Metson; O. J. E. Maroney; D. M. Newbold; F. F. Wilson; P. R. Hobson; A. Khan; P. Kyberd; J. J. Nebrensky; M. Bly; C. Brew; S. Burke; R. Byrom; J. Coles; L. A. Cornwall; A. Djaoui; L. Field; S. M. Fisher; G. T. Folkes; N. I. Geddes; J. C. Gordon; S. J. C. Hicks; J. G. Jensen; G. Johnson; D P Kelsey; G. Kuznetsov; J. Leake; R. P. Middleton; G. N. Patrick; G. Prassas; B. J. Saunders; D. Ross; R. A. Sansum; T. Shah; B. Strong; O. Synge; R. Tam; M. Thorpe; S. Traylen; J. F. Wheeler; N. G. H. White; A. J. Wilson; I. Antcheva; E. Artiaga; J. Beringer; I. G. Bird; J. Casey; A. J. Cass; R. Chytracek; M. V. Gallas Torreira; J. Gene