Concept of indistinguishable particles in classical and quantum physics
Bach, A.
1988-06-01
The consequences of the following definition of indistinguishability are analyzed. Indistinguishable classical or quantum particles are identical classical or quantum particles in a state characterized by a probability measure, a statistical operator respectively, which is invariant under any permutation of the particles. According to this definition the particles of classical Maxwell-Boltzmann statistics are indistinguishable.
Counterfactual quantum-information transfer without transmitting any physical particles
Guo, Qi; Cheng, Liu-Yong; Chen, Li; Wang, Hong-Fu; Zhang, Shou
2015-01-01
We demonstrate quantum information can be transferred between two distant participants without any physical particles traveling between them. The key procedure of the counterfactual scheme is to entangle two nonlocal qubits with each other without interaction, so the scheme can also be used to generate nonlocal entanglement counterfactually. We here illustrate the scheme by using flying photon qubits and Rydberg atom qubits assisted by a mesoscopic atomic ensemble. Unlike the typical teleportation, the present scheme can transport an unknown qubit in a nondeterministic manner without prior entanglement sharing or classical communication between the two distant participants. PMID:25672936
Counterfactual quantum-information transfer without transmitting any physical particles.
Guo, Qi; Cheng, Liu-Yong; Chen, Li; Wang, Hong-Fu; Zhang, Shou
2015-01-01
We demonstrate quantum information can be transferred between two distant participants without any physical particles traveling between them. The key procedure of the counterfactual scheme is to entangle two nonlocal qubits with each other without interaction, so the scheme can also be used to generate nonlocal entanglement counterfactually. We here illustrate the scheme by using flying photon qubits and Rydberg atom qubits assisted by a mesoscopic atomic ensemble. Unlike the typical teleportation, the present scheme can transport an unknown qubit in a nondeterministic manner without prior entanglement sharing or classical communication between the two distant participants. PMID:25672936
Quantum Optics, Diffraction Theory, and Elementary Particle Physics
None
2011-10-06
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.
Physical qubits from charged particles: Infrared divergences in quantum information
Leon, Juan; Martin-Martinez, Eduardo
2009-05-15
We consider soft-photon effects (ir structure of QED) on the construction of physical qubits. Soft photons appear when we build charged qubits from the asymptotic states of QED. This construction is necessary in order to include the effect of soft photons on entanglement measures. The nonexistence of free charged particles (due to the long range of QED interactions) leads us to question the sense of the very concept of free charged qubit. In this work, using the ''dressing'' formalism, we build physical charged qubits from dressed fields which have the correct asymptotic behavior, are gauge invariant, have propagators with a particle pole structure, and are free from infrared divergences. Finally, we discuss the impact of the soft corrections on the entanglement measures.
Self-Localized Quasi-Particle Excitation in Quantum Electrodynamics and Its Physical Interpretation
NASA Astrophysics Data System (ADS)
Feranchuk, Ilya D.; Feranchuk, Sergey I.
2007-12-01
The self-localized quasi-particle excitation of the electron-positron field (EPF) is found for the first time in the framework of a standard form of the quantum electrodynamics. This state is interpreted as the ''physical'' electron (positron) and it allows one to solve the following problems: i) to express the ''primary'' charge e0 and the mass m0 of the ''bare'' electron in terms of the observed values of e and m of the ''physical'' electron without any infinite parameters and by essentially nonperturbative way; ii) to consider μ-meson as another self-localized EPF state and to estimate the ratio mμ/m; iii) to prove that the self-localized state is Lorentz-invariant and its energy spectrum corresponds to the relativistic free particle with the observed mass m; iv) to show that the expansion in a power of the observed charge e << 1 corresponds to the strong coupling e! xpansion in a power of the ''primary'' charge e-10 ~ e when the interaction between the ``physical'' electron and the transverse electromagnetic field is considered by means of the perturbation theory and all terms of this series are free from the ultraviolet divergence.
Quantum Physics for Beginners.
ERIC Educational Resources Information Center
Strand, J.
1981-01-01
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)
Research in theoretical particle physics
McKay, D.W.; Munczek, H.; Ralston, J.
1992-05-01
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)
Research in theoretical particle physics
NASA Astrophysics Data System (ADS)
McKay, D. W.; Munczek, H.; Ralston, J.
1992-05-01
An update of ongoing work at Kansas University is presented. 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.
"Loops and Legs in Quantum Field Theory", 12th DESY Workshop on Elementary Particle Physics
NASA Astrophysics Data System (ADS)
The bi-annual international conference "Loops and Legs in Quantum Field Theory" has been held at Weimar, Germany, from April 27 to May 02, 2014. It has been the 12th conference of this series, started in 1992. The main focus of the conference are precision calculations of multi- loop and multi-leg processes in elementary particle physics for processes at present and future high-energy facilities within and beyond the Standard Model. At present many physics questions studied deal with processes at the LHC and future facilities like the ILC. A growing number of contributions deals with important developments in the field of computational technologies and algorithmic methods, including large-scale computer algebra, efficient methods to compute large numbers of Feynman diagrams, analytic summation and integration methods of various kinds, new related function spaces, precise numerical methods and Monte Carlo simulations. The present conference has been attended by more than 110 participants from all over the world, presenting more than 75 contributions, most of which have been written up for these pro- ceedings. The present volume demonstrates in an impressive way the enormous development of the field during the last few years, reaching the level of 5-loop calculations in QCD and a like- wise impressive development in massive next-to-leading order and next-to-next-to-leading order processes. Computer algebraic and numerical calculations require terabyte storage and many CPU years, even after intense parallelization, to obtain state-of-the-art theoretical predictions. The city of Weimar gave a suitable frame to the conference, with its rich history, especially in literature, music, arts, and architecture. Goethe, Schiller, Wieland, Herder, Bach and Liszt lived there and created many of their masterpieces. The many young participants signal that our field is prosperous and faces an exciting future. The conference hotel "Kaiserin Augusta" offered a warm hospitality and excellent working conditions. We would like to thank Martina Mende for all her work in helping to organize this conference. Details of the conference can be found under: https://indico.desy.de/conferenceDisplay.py?confId=8107
The Birth of Elementary-Particle Physics.
ERIC Educational Resources Information Center
Brown, Laurie M.; Hoddeson, Lillian
1982-01-01
Traces the origin and development of particle physics, concentrating on the roles of cosmic rays and theory. Includes charts highlighting significant events in the development of cosmic-ray physics and quantum field theory. (SK)
Studies in theoretical particle physics
Kaplan, D.B.
1992-08-01
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.
Perspectives on particle physics
Matsuda, S.; Muta, T.; Sasaki, R
1988-01-01
The book is dedicated to Prof. H Miyazawa in commemoration of his 60th birthday. Prof. H Miyazawa is an outstanding particle physicist who gave an original idea on nuclear magnetic moments and has led the frontier of particle physics. Here is a historical survey featuring the stress on phenomenologies in particle physics.
Rosenfeld, Carl; Mishra, Sanjib R.; Petti, Roberto; Purohit, Milind V.
2014-08-31
The high energy physics group at the University of South Carolina, under the leadership of Profs. S.R. Mishra, R. Petti, M.V. Purohit, J.R. Wilson (co-PI's), and C. Rosenfeld (PI), engaged in studies in "Experimental Particle Physics." The group collaborated with similar groups at other universities and at national laboratories to conduct experimental studies of elementary particle properties. We utilized the particle accelerators at the Fermi National Accelerator Laboratory (Fermilab) in Illinois, the Stanford Linear Accelerator Center (SLAC) in California, and the European Center for Nuclear Research (CERN) in Switzerland. Mishra, Rosenfeld, and Petti worked predominantly on neutrino experiments. Experiments conducted in the last fifteen years that used cosmic rays and the core of the sun as a source of neutrinos showed conclusively that, contrary to the former conventional wisdom, the "flavor" of a neutrino is not immutable. A neutrino of flavor "e," "mu," or "tau," as determined from its provenance, may swap its identity with one of the other flavors -- in our jargon, they "oscillate." The oscillation phenomenon is extraordinarily difficult to study because neutrino interactions with our instruments are exceedingly rare -- they travel through the earth mostly unimpeded -- and because they must travel great distances before a substantial proportion have made the identity swap. Three of the experiments that we worked on, MINOS, NOvA, and LBNE utilize a beam of neutrinos from an accelerator at Fermilab to determine the parameters governing the oscillation. Two other experiments that we worked on, NOMAD and MIPP, provide measurements supportive of the oscillation experiments. Good measurements of the neutrino oscillation parameters may constitute a "low energy window" on related phenomena that are otherwise unobservable because they would occur only at energies way above the reach of conceivable accelerators. Purohit and Wilson participated in the BaBar experiment, which collected data at SLAC until 2008. They continued to analyze the voluminous BaBar data with an emphasis on precision tests of Quantum Chromodynamics and on properties of the "eta_B," a bottom quark paired in a meson with a strange quark. The ATLAS experiment became the principal research focus for Purohit. One of the world's largest pieces of scientific equipment, ATLAS observes particle collisions at the highest-energy particle accelerator ever built, the Large Hadron Collider (LHC) at CERN. Our efforts on ATLAS included participation in the commissioning, calibration, and installation of components called "CSCs". The unprecedented energy of 14 TeV enabled the ATLAS and CMS collaborations to declare discovery of the famous Higgs particle in 2012.
NASA Astrophysics Data System (ADS)
Haag, Rudolf
We review conceptual structures met in quantum physics and note changes of basic concepts and language partly due to a maturing process in the 80 odd years since their first evocation by the founding fathers in Copenhagen, partly demanded or suggested by the passage from quantum mechanics to relativistic quantum field theory, local quantum physics and high energy experiments. It is in particular the concept of "observable" which lost its central role as a description of the measurement of some hypothetical property of a "physical system" under investigation and shifted to an auxiliary position as referring to a detector whose signals serve for the reconstruction of a history described in equations like (9.6), (9.7). The primary role is taken over by the notion of a (microscopic) event constituting the bridge to reality and to finer features of space-time.
Finite groups and quantum physics
Kornyak, V. V.
2013-02-15
Concepts of quantum theory are considered from the constructive 'finite' point of view. The introduction of a continuum or other actual infinities in physics destroys constructiveness without any need for them in describing empirical observations. It is shown that quantum behavior is a natural consequence of symmetries of dynamical systems. The underlying reason is that it is impossible in principle to trace the identity of indistinguishable objects in their evolution-only information about invariant statements and values concerning such objects is available. General mathematical arguments indicate that any quantum dynamics is reducible to a sequence of permutations. Quantum phenomena, such as interference, arise in invariant subspaces of permutation representations of the symmetry group of a dynamical system. Observable quantities can be expressed in terms of permutation invariants. It is shown that nonconstructive number systems, such as complex numbers, are not needed for describing quantum phenomena. It is sufficient to employ cyclotomic numbers-a minimal extension of natural numbers that is appropriate for quantum mechanics. The use of finite groups in physics, which underlies the present approach, has an additional motivation. Numerous experiments and observations in the particle physics suggest the importance of finite groups of relatively small orders in some fundamental processes. The origin of these groups is unclear within the currently accepted theories-in particular, within the Standard Model.
NASA Astrophysics Data System (ADS)
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.; Mnig, K.; Montanet, L.; Feng, J. L.; Murayama, H.; Hernndez, J. J.; Manohar, A.; Aguilar-Benitez, M.; Caso, C.; Crawford, R. L.; Roos, M.; Trnqvist, 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
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.
Arndt, Markus; Juffmann, Thomas; Vedral, Vlatko
2009-01-01
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. PMID:20234806
Haken, H.; Wolf, H.C.
1987-01-01
Atomic physics and the underlying quantum theory are the point of departure for many modern areas of physics, astrophysics, chemistry, biology, and even electrical engineering. This textbook provides a careful introduction to the results of methods of empirical atomic physics. A chapter on the quantum theory of the chemical bond provides an introduction to molecular physics. The authors also discuss laser physics and nonlinear spectroscopy, incorporating latest experimental results, and showing their relevance to basic research. Additional items included in the second edition are solutions to the exercises, derivations of the relativistic Klein-Gordon and Dirac equations, a detailed theoretical derivation of the Lamb shift, a discussion of new developments in the spectroscopy of inner shells, and new applications of NMR spectroscopy.
Advanced Level Physics Students' Conceptions of Quantum Physics.
ERIC Educational Resources Information Center
Mashhadi, Azam
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…
Research program in particle physics
Sudarshan, E.C.G.; Dicus, D.A.; Ritchie, J.L.; Lang, K.
1992-07-01
This report discusses the following topics: Quantum Gravity and Mathematical Physics; Phenomenology; Quantum Mechanics and Quantum Field Theory; Status of BNL Expt. 791; BNL Expt. 791; BNL Expt. 888; and SSC Activities.
Kearns, Edward
2013-07-12
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.
Quantum cellular automata without particles
NASA Astrophysics Data System (ADS)
Meyer, David A.; Shakeel, Asif
2016-01-01
Quantum cellular automata (QCA) constitute space and time homogeneous discrete models for quantum field theories (QFTs). Although QFTs are defined without reference to particles, computations are done in terms of Feynman diagrams, which are explicitly interpreted in terms of interacting particles. Similarly, the easiest QCA to construct are quantum lattice gas automata (QLGA). A natural question then is, which QCA are not QLGA? Here we construct a nontrivial example of such a QCA; it provides a simple model in 1 +1 dimensions with no particle interpretation at the scale where the QCA dynamics are homogeneous.
Particle physics and cosmology
Kolb, E.W.
1986-10-01
This series of lectures is about the role of particle physics in physical processes that occurred in the very early stages of the bug gang. Of particular interest is the role of particle physics in determining the evolution of the early Universe, and the effect of particle physics on the present structure of the Universe. The use of the big bang as a laboratory for placing limits on new particle physics theories will also be discussed. Section 1 reviews the standard cosmology, including primordial nucleosynthesis. Section 2 reviews the decoupling of weakly interacting particles in the early Universe, and discusses neutrino cosmology and the resulting limits that may be placed on the mass and lifetime of massive neutrinos. Section 3 discusses the evolution of the vacuum through phase transitions in the early Universe and the formation of topological defects in the transitions. Section 4 covers recent work on the generation of the baryon asymmetry by baryon-number violating reactions in Grand Unified Theories, and mentions some recent work on baryon number violation effects at the electroweak transition. Section 5 is devoted to theories of cosmic inflation. Finally, Section 6 is a discussion of the role of extra spatial dimensions in the evolution of the early Universe. 78 refs., 32 figs., 6 tabs.
Cosmology and Particle Physics
NASA Astrophysics Data System (ADS)
Steigman, G.
1982-01-01
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.
Quantum optics. Gravity meets quantum physics
Adams, Bernhard W.
2015-02-27
Albert Einstein’s general theory of relativity is a classical formulation but a quantum mechanical description of gravitational forces is needed, not only to investigate the coupling of classical and quantum systems but simply to give a more complete description of our physical surroundings. In this issue of Nature Photonics, Wen-Te Liao and Sven Ahrens reveal a link between quantum and gravitational physics. They propose that in the quantum-optical effect of superradiance, the world line of electromagnetic radiation is changed by the presence of a gravitational field.
Increasing complexity with quantum physics.
Anders, Janet; Wiesner, Karoline
2011-09-01
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
Field theory and particle physics
Eboli, O.J.P.; Gomes, M.; Santoro, A.
1990-01-01
This book contains the proceedings of the topics covered during the fifth Jorge Andre Swieca Summer School. The first part of the book collects the material devoted to quantum field theory. There were four courses on methods in Field Theory; H. O. Girotti lectured on constrained dynamics, R. Jackiw on the Schrodinger representation in Field Theory, S.-Y. Pi on the application of this representation to quantum fields in a Robertson-Walker spacetime, and L. Vinet on Berry Connections. There were three courses on Conformal Field Theory: I. Todorov focused on the problem of construction and classification of conformal field theories. Lattice models, two-dimensional S matrices and conformal field theory were looked from the unifying perspective of the Yang-Baxter algebras in the lectures given by M. Karowski. Parasupersymmetric quantum mechanics was discussed in the lectures by L. Vinet. Besides those courses, there was an introduction to string field theory given by G. Horowitz. There were also three seminars: F. Schaposnik reported on recent applications of topological methods in field theory, P. Gerbert gave a seminar on three dimensional gravity and V. Kurak talked on two dimensional parafermionic models. The second part of this proceedings is devoted to phenomenology. There were three courses on Particle Physics: Dan Green lectured on collider physics, E. Predrazzi on strong interactions and G. Cohen-Tanoudji on the use of strings in strong interactions.
Quantum vacuum noise in physics and cosmology.
Davies, P. C. W.
2001-09-01
The concept of the vacuum in quantum field theory is a subtle one. Vacuum states have a rich and complex set of properties that produce distinctive, though usually exceedingly small, physical effects. Quantum vacuum noise is familiar in optical and electronic devices, but in this paper I wish to consider extending the discussion to systems in which gravitation, or large accelerations, are important. This leads to the prediction of vacuum friction: The quantum vacuum can act in a manner reminiscent of a viscous fluid. One result is that rapidly changing gravitational fields can create particles from the vacuum, and in turn the backreaction on the gravitational dynamics operates like a damping force. I consider such effects in early universe cosmology and the theory of quantum black holes, including the possibility that the large-scale structure of the universe might be produced by quantum vacuum noise in an early inflationary phase. I also discuss the curious phenomenon that an observer who accelerates through a quantum vacuum perceives a bath of thermal radiation closely analogous to Hawking radiation from black holes, even though an inertial observer registers no particles. The effects predicted raise very deep and unresolved issues about the nature of quantum particles, the role of the observer, and the relationship between the quantum vacuum and the concepts of information and entropy. (c) 2001 American Institute of Physics. PMID:12779491
Challenges and Opportunities in Particle Physics
NASA Astrophysics Data System (ADS)
Ellis, John
2001-09-01
The Standard Model of particle physics describes very accurately all confirmed experimental data from accelerators. It leaves unanswered the origin of particle masses, the unification of the fundamental interactions, and the nature of a quantum theory of gravity. Particle masses may originate from a Higgs boson, and data from CERN's LEP accelerator have provided a first hint for its existence. Data on solar and atmospheric neutrinos indicate that neutrinos have masses, as suggested by grand unified theories. Astrophysics and cosmology may provide other hints about physics at very high energies. Central to the quest for the Higgs and other new particles will be CERN's next accelerator, the LHC.
Physics as quantum information processing: Quantum fields as quantum automata
NASA Astrophysics Data System (ADS)
D'Ariano, Giacomo Mauro
2012-03-01
Can we reduce Quantum Field Theory (QFT) to a quantum computation? Can physics be simulated by a quantum computer? Do we believe that a quantum field is ultimately made of a numerable set of quantum systems that are unitarily interacting? A positive answer to these questions corresponds to substituting QFT with a theory of quantum cellular automata (QCA), and the present work is examining this hypothesis. These investigations are part of a large research program on a quantum-digitalization of physics, with Quantum Theory as a special theory of information, and Physics as emergent from the same quantum-information processing. A QCA-based QFT has tremendous potential advantages compared to QFT, being quantum ab-initio and free from the problems plaguing QFT due to the continuum hypothesis. Here I will show how dynamics emerges from the quantum processing, how the QCA can reproduce the Dirac-field phenomenology at large scales, and the kind of departures from QFT that that should be expected at a Planckscale discreteness. I will introduce the notions of linear field quantum automaton and local-matrix quantum automaton, in terms of which I will provide the solution to the Feynman's problem about the possibility of simulating a Fermi field with a quantum computer.
Cosmology and particle physics
NASA Technical Reports Server (NTRS)
Turner, Michael S.
1988-01-01
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.
Lithography using quantum entangled particles
NASA Technical Reports Server (NTRS)
Williams, Colin (Inventor); Dowling, Jonathan (Inventor)
2001-01-01
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.
Lithography using quantum entangled particles
NASA Technical Reports Server (NTRS)
Williams, Colin (Inventor); Dowling, Jonathan (Inventor)
2003-01-01
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.
Quantum computing classical physics.
Meyer, David A
2002-03-15
In the past decade, quantum algorithms have been found which outperform the best classical solutions known for certain classical problems as well as the best classical methods known for simulation of certain quantum systems. This suggests that they may also speed up the simulation of some classical systems. I describe one class of discrete quantum algorithms which do so--quantum lattice-gas automata--and show how to implement them efficiently on standard quantum computers. PMID:16210187
Physics of windblown particles
NASA Technical Reports Server (NTRS)
Greeley, Ronald; Leach, Rodman; Marshall, John R.; White, Bruce; Iversen, James D.; Nickling, William G.; Gillette, Dale; Sorensen, Michael
1987-01-01
A laboratory facility proposed for the Space Station to investigate fundamental aspects of windblown particles is described. The experiments would take advantage of the environment afforded in earth orbit and would be an extension of research currently being conducted on the geology and physics of windblown sediments on earth, Mars, and Venus. Aeolian (wind) processes are reviewed in the planetary context, the scientific rational is given for specific experiments to be conducted, the experiment apparatus (the Carousel Wind Tunnel, or CWT) is described, and a plan presented for implementing the proposed research program.
The Physics of Quantum Computation
NASA Astrophysics Data System (ADS)
Falci, Giuseppe; Paladino, Elisabette
2015-10-01
Quantum Computation has emerged in the past decades as a consequence of down-scaling of electronic devices to the mesoscopic regime and of advances in the ability of controlling and measuring microscopic quantum systems. QC has many interdisciplinary aspects, ranging from physics and chemistry to mathematics and computer science. In these lecture notes we focus on physical hardware, present day challenges and future directions for design of quantum architectures.
Elementary Particles and the Laws of Physics
NASA Astrophysics Data System (ADS)
Feynman, Richard P.; Weinberg, Steven
1987-11-01
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.
Studies in theoretical particle physics. Progress report
Kaplan, D.B.
1992-08-01
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.
Parables of physics and a quantum romance
NASA Astrophysics Data System (ADS)
Machacek, A. C.
2014-01-01
Teachers regularly use stories to amplify the concepts taught and to encourage student engagement. The literary form of a parable is particularly suitable for classroom use, and examples are given, including a longer one intended to stimulate discussion on the nature of quantum physics (and the wave-particle duality in particular).
Parables of Physics and a Quantum Romance
ERIC Educational Resources Information Center
Machacek, A. C.
2014-01-01
Teachers regularly use stories to amplify the concepts taught and to encourage student engagement. The literary form of a parable is particularly suitable for classroom use, and examples are given, including a longer one intended to stimulate discussion on the nature of quantum physics (and the wave-particle duality in particular).
NASA Astrophysics Data System (ADS)
Christensen, Walter James
2015-10-01
After a straightforward general relativistic calculation on a modified flat-spacetime metric (developed from the fluctuating vacuum energy interacting with a graviton field), a pair of n-valued covariant and contravariant energy momentum tensors emerged analogous to quantized raising and lower operators. Detaching these operators from the general relativistic field equations, and then transporting them to act on extreme spacetimes, these operators were able to generate fundamental particle boson masses. In particular, the operators precisely generated Higgs mass. Then by applying a consistency approach to the gravitational field equations - similar to how Maxwell applied to the electromagnetic ones - it allowed for the coupling of spin-to-mass, further restricting the particle mass to be in precise agreement with CODATA experimental values. Since this is a massless field approach integrated discretely with a massive one, it overcomes various renormalizing difficulties; moreover it solves the mass hierarchal problem of the Standard Model of particle physics, and generates its spin and therefore shows quantum physics to be a subset of General Relativity, just as Einstein had first imagined.
Particle physics---Experimental
Lord, J.J.; Boynton, P.E.; Burnett, T.H.; Wilkes, R.J.
1991-08-21
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.
Teaching Quantum Physics without Paradoxes
ERIC Educational Resources Information Center
Hobson, Art
2007-01-01
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
Teaching Quantum Physics without Paradoxes
ERIC Educational Resources Information Center
Hobson, Art
2007-01-01
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…
Quantum evaporation of flavor-mixed particles
NASA Astrophysics Data System (ADS)
Medvedev, Mikhail V.
2014-03-01
Particles whose propagation (mass) and interaction (flavor) bases are misaligned are mixed, e.g., neutrinos, quarks, Kaons, etc. We show that interactions (elastic scattering) of individual mass-eigenstates can result in their inter-conversions. Most intriguing and counter-intuitive implication of this process is a new process, which we refer to as the ``quantum evaporation.'' Consider a mixed particle trapped in a gravitational potential. If such a particle scatters off something (e.g., from another mixed particle) elastically from time to time, this particle (or both particles, respectively) can eventually escape to infinity with no extra energy supplied. That is as if a ``flavor-mixed satellite'' hauled along a bumpy road puts itself in space without a rocket, fuel, etc. Of course, the process at hand is entirely quantum and has no counterpart in classical mechanics. It also has nothing to do with tunneling or other known processes. We discuss some implications to the dark matter physics, cosmology and cosmic neutrino background. Supported by grant DOE grant DE-FG02-07ER54940 and NSF grant AST-1209665.
Research in elementary particle physics
NASA Astrophysics Data System (ADS)
Kirsch, L. E.; Schnitzer, H. J.; Bensinger, J. R.; Blocker, C. A.
1992-05-01
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.
NASA Astrophysics Data System (ADS)
Chen, Gang; Liang, Jiu-Qing
2009-05-01
In this paper we theoretically report an unconventional quantum phase transition of a simple Lipkin-Meshkov-Glick model: an interacting collective spin system without external magnetic field. It is shown that this model with integer-spin can exhibit a first-order quantum phase transition between different disordered phases, and more intriguingly, possesses a hidden supersymmetry at the critical point. However, for half-integer spin we predict another first-order quantum phase transition between two different long-range-ordered phases with a vanishing energy gap, which is induced by the destructive topological quantum interference between the intanton and anti-instanton tunneling paths and accompanies spontaneously breaking of supersymmetry at the same critical point. We also show that, when the total spin-value varies from half-integer to integer this model can exhibit an abrupt variation of Berry phase from π to zero.
Multiple-Particle Interference and Quantum Error Correction
NASA Astrophysics Data System (ADS)
Steane, Andrew
1996-11-01
The concept of multiple-particle interference is discussed, using insights provided by the classical theory of error correcting codes. This leads to a discussion of error correction in a quantum communication channel or a quantum computer. Methods of error correction in the quantum regime are presented, and their limitations assessed. A quantum channel can recover from arbitrary decoherence of x qubits if K bits of quantum information are encoded using n quantum bits, where K/n can be greater than 1 - 2H (2x/n), but must be less than 1 - 2H (x/n). This implies exponential reduction of decoherence with only a polynomial increase in the computing resources required. Therefore quantum computation can be made free of errors in the presence of physically realistic levels of decoherence. The methods also allow isolation of quantum communication from noise and evesdropping (quantum privacy amplification).
Quantum mechanics emerging from stochastic dynamics of virtual particles
NASA Astrophysics Data System (ADS)
Tsekov, Roumen
2016-03-01
It is shown how quantum mechanics emerges from the stochastic dynamics of force carriers. It is demonstrated that the Moyal equation corresponds to dynamic correlations between the real particle momentum and the virtual particle position, which are not present in classical mechanics. This new concept throws light on the physical meaning of quantum theory, showing that the Planck constant square is a second-second position-momentum cross-cumulant.
Quantum physics and complex networks
NASA Astrophysics Data System (ADS)
Biamonte, Jacob
2014-03-01
There is a widely used and successful theory of ``chemical reaction networks,'' which provides a framework describing systems governed by mass action kinetics. Computer science and population biology use the same ideas under a different name: ``stochastic Petri nets.'' But if we look at these theories from the perspective of quantum theory, they turn out to involve creation and annihilation operators, coherent states and other well-known ideas--yet in a context where probabilities replace amplitudes. I will explain this connection as part of a detailed analogy between quantum mechanics and stochastic mechanics which we've produced several results on recently, including the recent analytical results uniting quantum physics and complex networks. Our general idea is about merging concepts from quantum physics and complex network theory to provide a bidirectional bridge between both disciplines. Support is acknowledged from the Foundational Questions Institute (FQXi) and the Compagnia di San Paolo Foundation.
Helio Takai
2010-01-08
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
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,
Quantum Hamiltonian Physics with Supercomputers
NASA Astrophysics Data System (ADS)
Vary, James P.
2014-06-01
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.
Quantum resonances in physical tunneling
NASA Astrophysics Data System (ADS)
Nieto, M. M.; Truax, D. R.
It has recently been emphasized that the probability of quantum tunneling is a critical function of the shape of the potential. Applying this observation to physical systems, we point out that in principal information on potential surfaces can be obtained by studying tunneling rates. This is especially true in cases where only spectral data are known, since many potentials yield the same spectrum.
New frontiers in particle physics
Cameron, J.M.; Campbell, B.A.; Kamal, A.N.; Khanna, F.C.
1986-01-01
This book reviews the papers presented in meetings of new developments in particle physics. Topics covered are: hadron physics; lepton flavor violation; new particle searchers by double beta decay; solar neutrino problem; decays of the B mason; ARGUS Physics from D mesons; reviews of B meson at-PEP; Higher dimensional gravity; superstring theories; Gauginos from pp-bar collisions; two photon Decay widths of non-standard spin-o bosons; status g CDF experiment; light-cone gauge;' and the axial QED anomaly.
NASA Astrophysics Data System (ADS)
Izen, Joseph M.
1994-10-01
The University of Texas at Dallas (UTD) is participating in two e(+)e(-), experiments, Beijing Spectrometer (BES) and BABAR, the PEP-11 B Factory detector. Associated production of tau and charmed mesons allow for absolute branching fraction measurements with good control of backgrounds. BES is uniquely positioned to study the leptonic and hadronic decays of quarkonia. The Beijing Electron Positron Collider (BEPC) delivers luminosities an order of magnitude higher than earlier facilities. BES and BEPC will be upgraded following the 1994-5 run, and will resume data taking in Fall, 1996 with an improved detector and a Three-fold increase in luminosity. The raison d'etre of BABAR is the exploration of CP violation in the B meson system. An asymmetric storage ring is required to observe the time-dependence of the CP asymmetry. Other BABAR physics includes measurements of CKM matrix elements, rare B decays, penguin diagrams, B(sub s) decays, and precision measurements of tau and D meson decays. The scheduled BABAR turn-on in 1999 provides the UTD group with a natural evolution with continuous physics during this period.
Unifying Quantum Physics with Biology
NASA Astrophysics Data System (ADS)
Goradia, Shantilal
2014-09-01
We find that the natural logarithm of the age of the universe in quantum mechanical units is close to 137. Since science is not religion, it is our moral duty to recognize the importance of this finding on the following ground. The experimentally obtained number 137 is a mystical number in science, as if written by the hand of God. It is found in cosmology; unlike other theories, it works in biology too. A formula by Boltzmann also works in both: biology and physics, as if it is in the heart of God. His formula simply leads to finding the logarithm of microstates. One of the two conflicting theories of physics (1) Einstein's theory of General Relativity and (2) Quantum Physics, the first applies only in cosmology, but the second applies in biology too. Since we have to convert the age of the universe, 13 billion years, into 1,300,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 Planck times to get close to 137, quantum physics clearly shows the characteristics of unifying with biology. The proof of its validity also lies in its ability to extend information system observed in biology.
Thermalization in Many-Particle Quantum Walks
NASA Astrophysics Data System (ADS)
Musumbu, Dibwe Pierrot; Przybylska, Maria; Maciejewski, Andrzej J.
2016-03-01
Many-particle quantum walks of particles obeying Bose statistics, moving on graphs of various topologies are introduced. A single coin tossing commands the conditional shift operation over the whole graph. Vertex particle densities, mean values of phase space variables, second order spatial correlations and counting statistics are evaluated and simulated. The evidence of universal dynamics is presented.
Quantum fingerprinting with a single particle
Massar, S.
2005-01-01
We show that the two-slit experiment in which a single quantum particle interferes with itself can be interpreted as a quantum fingerprinting protocol: the interference pattern exhibited by the particle contains information about the environment it encountered in the slits which would require much more communication to learn classically than is required quantum mechanically. An extension to the case where the particle has many internal degrees of freedom is suggested, and its interpretation is discussed. The interpretation of these results is discussed in detail, and a possible experimental realization is proposed.
Clothed Particles in Quantum Electrodynamics and Quantum Chromodynamics
NASA Astrophysics Data System (ADS)
Shebeko, Alexander
2016-03-01
The notion of clothing in quantum field theory (QFT), put forward by Greenberg and Schweber and developed by M. Shirokov, is applied in quantum electrodynamics (QED) and quantum chromodynamics (QCD). Along the guideline we have derived a novel analytic expression for the QED Hamiltonian in the clothed particle representation (CPR). In addition, we are trying to realize this notion in QCD (to be definite for the gauge group SU(3)) when drawing parallels between QCD and QED.
A research Program in Elementary Particle Physics
Sobel, Henry; Molzon, William; Lankford, Andrew; Taffard, Anyes; Whiteson, Daniel; Kirkby, David
2013-07-25
Work is reported in: Neutrino Physics, Cosmic Rays and Elementary Particles; Particle Physics and Charged Lepton Flavor Violation; Research in Collider Physics; Dark Energy Studies with BOSS and LSST.
EPR paradox, quantum nonlocality and physical reality
NASA Astrophysics Data System (ADS)
Kupczynski, M.
2016-03-01
Eighty years ago Einstein, Podolsky and Rosen demonstrated that instantaneous reduction of wave function, believed to describe completely a pair of entangled physical systems, led to EPR paradox. The paradox disappears in statistical interpretation of quantum mechanics (QM) according to which a wave function describes only an ensemble of identically prepared physical systems. QM predicts strong correlations between outcomes of measurements performed on different members of EPR pairs in far-away locations. Searching for an intuitive explanation of these correlations John Bell analysed so called local realistic hidden variable models and proved that correlations consistent with these models satisfy Bell inequalities which are violated by some predictions of QM and by experimental data. Several different local models were constructed and inequalities proven. Some eminent physicists concluded that Nature is definitely nonlocal and that it is acting according to a law of nonlocal randomness. According to these law perfectly random, but strongly correlated events, can be produced at the same time in far away locations and a local and causal explanation of their occurrence cannot be given. We strongly disagree with this conclusion and we prove the contrary by analysing in detail some influential finite sample proofs of Bell and CHSH inequalities and so called Quantum Randi Challenges. We also show how one can win so called Bell's game without violating locality of Nature. Nonlocal randomness is inconsistent with local quantum field theory, with standard model in elementary particle physics and with causal laws and adaptive dynamics prevailing in the surrounding us world. The experimental violation of Bell-type inequalities does not prove the nonlocality of Nature but it only confirms a contextual character of quantum observables and gives a strong argument against counterfactual definiteness and against a point of view according to which experimental outcomes are produced in irreducible random way.
Analysis of the two-particle controlled interacting quantum walks
NASA Astrophysics Data System (ADS)
Li, Dan; Zhang, Jie; Ma, Xiu-Wen; Zhang, Wei-Wei; Wen, Qiao-Yan
2013-06-01
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.
Supersymmetry in Elementary Particle Physics
Peskin, Michael E.; /SLAC
2008-02-05
These lectures give a general introduction to supersymmetry, emphasizing its application to models of elementary particle physics at the 100 GeV energy scale. I discuss the following topics: the construction of supersymmetric Lagrangians with scalars, fermions, and gauge bosons, the structure and mass spectrum of the Minimal Supersymmetric Standard Model (MSSM), the measurement of the parameters of the MSSM at high-energy colliders, and the solutions that the MSSM gives to the problems of electroweak symmetry breaking and dark matter.
The Quantum Geometer's Universe:. Particles, Interactions and Topology
NASA Astrophysics Data System (ADS)
Govaerts, Jan
2002-10-01
With the two most profound conceptual revolutions of XXth century physics, quantum mechanics and relativity, which have culminated into relativistic spacetime geometry and quantum gauge field theory as the principles for gravity and the three other known fundamental interactions, the physicist of the XXIst century has inherited an unfinished symphony: the unification of the quantum and the continuum. As an invitation to tomorrow's quantum geometers who must design the new rulers by which to size up the Universe at those scales where the smallest meets the largest, these lectures review the basic principles of today's conceptual framework, and highlight by way of simple examples the interplay that presently exists between the quantum world of particle interactions and the classical world of geometry and topology.
Quantum physics and the beam splitter mystery
NASA Astrophysics Data System (ADS)
Hnault, Franois
2015-09-01
Optical lossless beam splitters are frequently encountered in fundamental physics experiments regarding the nature of light, including "which-way" determination or the EPR paradox and their measurement apparatus. Although they look as common optical components at first glance, their behaviour remains somewhat mysterious since they apparently exhibit stand-alone particle-like features, and then wave-like characteristics when inserted into a Mach-Zehnder interferometer. In this communication are examined and discussed some basic properties of these beamssplitters, both from a classical optics and quantum physics point of view. Herein the most evident convergences and contradictions are highlighted, and the results of a few emblematic experiments demonstrating photon existence are discussed. Alternative empirical models are also proposed in order to shed light on some remaining issues.
Research in particle physics. [Dept. of Physics, Boston Univ
Whitaker, Scott J.
1992-09-01
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.
Quantum teleportation with identical particles
NASA Astrophysics Data System (ADS)
Marzolino, Ugo; Buchleitner, Andreas
2015-03-01
We study teleportation with identical massive particles. Indistinguishability imposes that the relevant degrees of freedom to be teleported are not particles, but rather addressable orthogonal modes. We discuss the performances of teleportation under the constraint of conservation of the total number of particles. The latter inevitably decreases the teleportation fidelity. Moreover, even though a phase reference, given by the coupling to a reservoir, circumvents the constraint, it does not restore perfect deterministic teleportation. The latter is only achievable with some special resource entangled states and when the number of particles tends to infinity. Interestingly, some of such states are the many-particle atomic coherent states and the ground state of cold atoms loaded into a double well potential, which are routinely prepared in experiments.
GPUs in experimental particle physics
NASA Astrophysics Data System (ADS)
Berger, Niklaus
2012-03-01
Many applications in particle and nuclear physics demand vast computational power with high throughput and low latency. Graphics Processing Units (GPUs) provide such massively parallel floating point computing power at low cost. Indeed many problems are easily parallelized and can be sped up by orders of magnitude by the use of GPUs. The talk will discuss two very different examples, namely the use of GPUs for partial wave analysis and on-line track reconstruction. Partial wave analysis is a key tool in hadron spectroscopy. The unbinned likelihood fits employed are an almost perfect match for the architecture of GPUs. GPU based partial wave analysis was pioneered at the Beijing Spectrometer III experiment in order to deal with world's largest datasets from electron-positron collisions in the charm threshold energy region and is now employed by many groups in the field. The presentation will describe the challenges for implementing a GPU based partial wave analysis and how they were overcome. Usually the most time consuming part of analysing particle physics events is the reconstruction of tracks of charged particles. A new generation of high rate experiments running without a hardware trigger (e.g. the LHCb upgrade, PANDA, a proposed μ->eee search) will be relying on very fast on-line event reconstruction, including tracking. This in turn requires massive amounts of computing power, which is currently best provided by GPUs. The talk will describe the state of GPU based tracking efforts.
Teaching Elementary Particle Physics: Part I1
NASA Astrophysics Data System (ADS)
Hobson, Art
2011-01-01
I'll outline suggestions for teaching elementary particle physics, often called high energy physics, in high school or introductory college courses for non-scientists or scientists. Some presentations of this topic simply list the various particles along with their properties, with little overarching structure. Such a laundry list approach is a great way to make a fascinating topic meaningless. Students need a conceptual framework from which to view the elementary particles. That conceptual framework is quantum field theory (QFT). Teachers and students alike tend to quake at this topic, but bear with me. We're talking here about concepts, not technicalities. My approach will be conceptual and suitable for non-scientists and scientists; if mathematical details are added in courses for future scientists, they should be simple and sparse. Introductory students should not be expected to do QFT, but only to understand its concepts. Those concepts take some getting used to, but they are simple and can be understood by any literate person, be she plumber, attorney, musician, or physicist.
Final Report: Particle Physics Research Program
Karchin, Paul E.
2011-09-01
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.
Quantum Security for the Physical Layer
Humble, Travis S
2013-01-01
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.
Topics in particle physics and cosmology
Hsu, S.D.H.
1991-08-02
The Standard Model of particle physics, together with the Big Bang model of the early universe, constitute a framework which encompasses our current understanding of fundamental laws and beginning of our universe. Despite recent speculative trends, quantum field theory remains the theoretical tool of choice for investigating new physics either at high energy colliders, or in the early universe. In this dissertation, several field theoretic phenomena relevant to cosmology or particle physics are explored. A common theme in these explorations is the structure of the vacuum state in quantum field theory. First, we discuss first-order phase transitions in the early universe, in which the effective vacuum state of the universe shifts discontinuously as the temperature drops below some critical point. We find that the dynamics of a certain type of first-order phase transition can lead to production of primordial black holes, which could constitute the dark matter of our universe. Alternatively, supercooled first-order phase transitions may be the cause of an extended inflationary epoch in the early universe, which is generally regarded as necessary to solve several cosmological puzzles. We derive limits on such scenarios based on nearly model-independent percolation properties of the transition. We also study some nonperturbative aspects of the field theory vacuum. We show that non-topological solitons of a single fermion and Higgs fields can only exist in strongly coupled theories. In particular, we find that at the lowest fermionic excitations in the Standard Model are single fermions, and not bound states of fermion plugs Higgs. Finally, we investigate the intriguing behavior of instanton-induced cross sections. We discover Higgs-Higgs cross sections which increase exponentially with center of mass energy due to the presence of instanton solutions related to vacuum instability.
Research in Elementary Particle Physics
White, Andrew Paul; De, Kaushik; Brandt, Andrew; Yu, Jaehoon; Farbin, Amir
2015-02-02
This report details the accomplishments and research results for the High Energy Physics Group at the University of Texas at Arlington at the Energy and Intensity Frontiers. For the Energy Frontier we have made fundamental contributions in the search for supersymmetric particles, proposed to explain the stabilization of the mass of the Higgs Boson – the agent giving mass to all known particles. We have also made major contributions to the search for additional Higgs Bosons and to the planning for future searches. This work has been carried out in the context of the ATLAS Experiment at CERN (European Nuclear Research Laboratory) and for which we have made major contributions to computing and data distribution and processing, and have worked to calibrate the detector and prepare upgraded electronics for the future. Our other contribution to the Energy Frontier has been to the International Linear Collider (ILC) project, potentially hosted by Japan, and to the Silicon Detector Concept (SiD) in particular. We have lead the development of the SiD Concept and have worked on a new form of precise energy measurement for particles from the high energy collisions of electrons and positrons at the ILC. For the Intensity Frontier, we have worked to develop the concept of Long Baseline Neutrino Experiment(s) (LBNE) at the Fermi National Accelerator Laboratory. Our contributions to detector development, neutrino beam studies, particle identification, software development will facilitate future studies of the oscillation of one type of neutrino into other type(s), establish the order of the neutrino masses, and, through an innovative new idea, allow us to create a beam of dark matter particles.
Innovative quantum technologies for microgravity fundamental physics and biological research
NASA Technical Reports Server (NTRS)
Kierk, I. K.
2002-01-01
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.
Innovative quantum technologies for microgravity fundamental physics and biological research
NASA Technical Reports Server (NTRS)
Kierk, I.; Israelsson, U.; Lee, M.
2001-01-01
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.
Simulating physical phenomena with a quantum computer
NASA Astrophysics Data System (ADS)
Ortiz, Gerardo
2003-03-01
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.
Particle creation from the quantum stress tensor
NASA Astrophysics Data System (ADS)
Firouzjaee, Javad T.; Ellis, George F. R.
2015-05-01
Among the different methods to derive particle creation, finding the quantum stress tensor expectation value gives a covariant quantity which can be used for examining the backreaction issue. However this tensor also includes vacuum polarization in a way that depends on the vacuum chosen. Here we review different aspects of particle creation by looking at energy conservation and at the quantum stress tensor. We show that in the case of general spherically symmetric black holes that have a dynamical horizon, as occurs in a cosmological context, one cannot have pair creation on the horizon because this violates energy conservation. This confirms the results obtained in other ways in a previous paper [J. T. Firouzjaee and G. F. R. Ellis, Gen. Relativ. Gravit. 47, 6 (2015)]. Looking at the expectation value of the quantum stress tensor with three different definitions of the vacuum state, we study the nature of particle creation and vacuum polarization in black hole and cosmological models, and the associated stress-energy tensors. We show that the thermal temperature that is calculated from the particle flux given by the quantum stress tensor is compatible with the temperature determined by the affine null parameter approach. Finally, we show that in the spherically symmetric dynamic case, we can neglect the backscattering term and only consider the s-wave term near the future apparent horizon.
A proposed physical analog for a quantum probability amplitude
NASA Astrophysics Data System (ADS)
Boyd, Jeffrey
What is the physical analog of a probability amplitude? All quantum mathematics, including quantum information, is built on amplitudes. Every other science uses probabilities; QM alone uses their square root. Why? This question has been asked for a century, but no one previously has proposed an answer. We will present cylindrical helices moving toward a particle source, which particles follow backwards. Consider Feynman's book QED. He speaks of amplitudes moving through space like the hand of a spinning clock. His hand is a complex vector. It traces a cylindrical helix in Cartesian space. The Theory of Elementary Waves changes direction so Feynman's clock faces move toward the particle source. Particles follow amplitudes (quantum waves) backwards. This contradicts wave particle duality. We will present empirical evidence that wave particle duality is wrong about the direction of particles versus waves. This involves a paradigm shift; which are always controversial. We believe that our model is the ONLY proposal ever made for the physical foundations of probability amplitudes. We will show that our ``probability amplitudes'' in physical nature form a Hilbert vector space with adjoints, an inner product and support both linear algebra and Dirac notation.
Quantum physics: Teleportation for two
NASA Astrophysics Data System (ADS)
Tittel, Wolfgang
2015-02-01
The 'no-cloning' theorem of quantum mechanics forbids the perfect copying of properties of photons or electrons. But quantum teleportation allows their flawless transfer -- now even for two properties simultaneously. See Letter p.516
Quantum turbulence visualized by particle dynamics
NASA Astrophysics Data System (ADS)
La Mantia, M.; Skrbek, L.
2014-07-01
The Lagrangian dynamics of micrometer-sized solid particles of hydrogen and deuterium is investigated in thermal counterflow of superfluid He4 at length scales ℓexp straddling about two orders of magnitude across the average distance ℓ between quantized vortices by using the particle tracking velocimetry technique. The normalized probability distribution functions of the particle velocities and accelerations change from the shapes typical of quantum turbulence, characterized by power-law tails, at length scales ℓexp≲ℓ, to forms similar to those obtained in classical turbulent flows, at ℓexp≳ℓ, although the power-law behavior of the acceleration distribution tails is less clear than that observed for the particle velocities. Moreover, the acceleration distribution follows a nearly log-normal, classical-like shape, at ℓ ≲ℓexp≲Lint, where Lint denotes the integral length scale, providing thus, within the just defined inertial range, experimental evidence of the existence of classical-like, macroscopic vortical structures in thermal counterflow of superfluid He4, which is traditionally regarded as a quantum flow with no obvious classical analog. Additionally, we report our observations of the added mass effect in quantum turbulence and discuss them in the framework of a developed model of particle dynamics.
Particle tunneling in a quantum corrected spacetime
NASA Astrophysics Data System (ADS)
Liu, Cheng-Zhou; Cao, Qiao-Jun
2015-01-01
Particle tunneling from a quantum corrected black hole in the gravity's rainbow was investigated by the radial trajectory method of the tunneling framework. Using the thermodynamic property of the event horizon, a simpler method for calculating the tunneling probability was shown. In this method, the Painleve coordinate transformation of spacetime and the radial trajectory equation of the tunneling particles used in the previous radial trajectory method was not used. Using the simpler method, the tunneling probability of outgoing particles, regardless of whether they are massless or massive, were calculated in a unified way. The emission rates were related to the changes of the black hole entropies before and after the emission. This implies that the emission spectrum agrees with the underling unitary theory. In addition, the Bekenstein-Hawking area for the modified black hole was established and the emission spectrum with quantum corrections was discussed.
Undergraduate computational physics projects on quantum computing
NASA Astrophysics Data System (ADS)
Candela, D.
2015-08-01
Computational projects on quantum computing suitable for students in a junior-level quantum mechanics course are described. In these projects students write their own programs to simulate quantum computers. Knowledge is assumed of introductory quantum mechanics through the properties of spin 1/2. Initial, more easily programmed projects treat the basics of quantum computation, quantum gates, and Grover's quantum search algorithm. These are followed by more advanced projects to increase the number of qubits and implement Shor's quantum factoring algorithm. The projects can be run on a typical laptop or desktop computer, using most programming languages. Supplementing resources available elsewhere, the projects are presented here in a self-contained format especially suitable for a short computational module for physics students.
A Synthetic Approach to the Transfer Matrix Method in Classical and Quantum Physics
ERIC Educational Resources Information Center
Pujol, O.; Perez, J. P.
2007-01-01
The aim of this paper is to propose a synthetic approach to the transfer matrix method in classical and quantum physics. This method is an efficient tool to deal with complicated physical systems of practical importance in geometrical light or charged particle optics, classical electronics, mechanics, electromagnetics and quantum physics. Teaching…
A Synthetic Approach to the Transfer Matrix Method in Classical and Quantum Physics
ERIC Educational Resources Information Center
Pujol, O.; Perez, J. P.
2007-01-01
The aim of this paper is to propose a synthetic approach to the transfer matrix method in classical and quantum physics. This method is an efficient tool to deal with complicated physical systems of practical importance in geometrical light or charged particle optics, classical electronics, mechanics, electromagnetics and quantum physics. Teaching
Links between quantum physics and thought.
Robson, Barry
2009-01-01
Quantum mechanics (QM) provides a variety of ideas that can assist in developing Artificial Intelligence for healthcare, and opens the possibility of developing a unified system of Best Practice for inference that will embrace both QM and classical inference. Of particular interest is inference in the hyperbolic-complex plane, the counterpart of the normal i-complex plane of basic QM. There are two reasons. First, QM appears to rotate from i-complex Hilbert space to hyperbolic-complex descriptions when observations are made on wave functions as particles, yielding classical results, and classical laws of probability manipulation (e.g. the law of composition of probabilities) then hold, whereas in the i-complex plane they do not. Second, i-complex Hilbert space is not the whole story in physics. Hyperbolic complex planes arise in extension from the Dirac-Clifford calculus to particle physics, in relativistic correction thereby, and in regard to spinors and twisters. Generalization of these forms resemble grammatical constructions and promote the idea that probability-weighted algebraic elements can be used to hold dimensions of syntactic and semantic meaning. It is also starting to look as though when a solution is reached by an inference system in the hyperbolic-complex, the hyperbolic-imaginary values disappear, while conversely hyperbolic-imaginary values are associated with the un-queried state of a system and goal seeking behavior. PMID:19745485
Quantum physics of molecular magnets
NASA Astrophysics Data System (ADS)
Jaafar, Reem
In this thesis we focus on various aspects of quantum physics in molecular magnets, in particular, in Mn12-acetate. This thesis is divided into three parts. In the first part, we present a review on molecular magnets. Since Mn 12-acetate has a large spin (equal to 10), the theory of tunneling of a large spin is discussed as well as the early experiments that were performed two decades ago and which has shown spin tunneling, in particular, the ones that were performed on gamma-Fe2O3 and on antiferromagnetic ferritin. Then, the first experiments that presented evidence on spin tunneling in Mn12-acetate are outlined in detail. Magnetic hysteresis curves are shown and Landau-Zener effect in molecular magnets is discussed. Quantum classical crossover between thermally assisted and pure quantum tunneling regimes is described. Finally, magnetic avalanches are introduced: they are another feature of the magnetization curve in Mn12-Acetate where there is a sudden reversal in the magnetization. We exploit the first two experiments performed to elucidate the nature of magnetic avalanches in Mn12-acetate and the theory developed as a result of these experiments. In the second part of this thesis, we focus on three of my publications on quantum magneto-mechanical effects. First, a recent experiment on Einstein-de Haas effect in a NiFe film deposited on a microcantilever is discussed. The cantilever was placed inside a coil that generated an ac magnetic field. Oscillation of the cantilever was measured by a fiber-optic interferometer positioned above the tip of the cantilever. When the frequency of the ac field matched the resonance frequency of the cantilever the amplitude of the oscillations was about 3 nm. The data were analyzed within a model that replaced the mechanical torque due to change in the magnetization with the effect of the periodic force acting on the fictitious point mass at the free end of the cantilever so this model did not account for the microscopic dynamics of the Einstein-de Haas effect. This motivated us to develop a more rigorous theoretical framework for the description of the dynamics of the Einstein-de Haas effect that we applied to the problem of the magnetic cantilever. We then study the quantum dynamics of a magnetic molecule deposited on a microcantilever. Amplitude and frequencies of the coupled magneto-mechanical oscillations have been computed. We show that oscillations of the spin and the cantilever occur independently at frequencies Delta/h and o n respectively, unless these two frequencies come very close to each other. The results show that the splitting delta has no free parameters and that for a given resonance, Delta = hon, the relative splitting delta depends only on the position of the molecule on the cantilever. We then show that existing experimental techniques permit observation of the driven coupled oscillations of the spin and the cantilever, as well as of the splitting of the mechanical modes of the cantilever caused by spin tunneling. Finally, the dynamics of a magnetic molecule bridged between two conducting leads is investigated. We start by reviewing various experiments performed when there is a weak coupling between the molecule and the leads and when there is a strong coupling which results in the Kondo effect. Experimental efforts were mainly motivated to measure the electronic current through a single molecule. We study the dynamics of the total angular momentum that couples spin tunneling to the mechanical rotations. We show that the Landau-Zener spin transition produced by the time-dependent magnetic field generates a unique pattern of mechanical oscillations that can be detected by measuring the electronic tunneling current through the molecule. In the last and final part, we present our numerical work to describe quantum magnetic deflagration in Mn12-acetate. This part is related to magnetic deflagration as discussed in part I of this thesis. The focus is on the quantum features of magnetic deflagration which are exhibited by the maxima in the speed of deflagration front as a function of the applied magnetic field. We review recent work on the effect of the dipolar field in forming self-organized fronts of spin tunneling, and present our enhanced computational work on the calculation of the relaxation rate. Previously, spin relaxation rates were calculated using a simple Arrhenius exponent. In this thesis we calculate the relaxation rate as a function of both the external field and temperature using the density matrix formalism and use them to study the effect of the transverse field on the front speed of deflagration.
Non-Perturbative, Unitary Quantum-Particle Scattering Amplitudes from Three-Particle Equations
Lindesay, James V
2002-03-19
We here use our non-perturbative, cluster decomposable relativistic scattering formalism to calculate photon-spinor scattering, including the related particle-antiparticle annihilation amplitude. We start from a three-body system in which the unitary pair interactions contain the kinematic possibility of single quantum exchange and the symmetry properties needed to identify and substitute antiparticles for particles. We extract from it unitary two-particle amplitude for quantum-particle scattering. We verify that we have done this correctly by showing that our calculated photon-spinor amplitude reduces in the weak coupling limit to the usual lowest order, manifestly covariant (QED) result with the correct normalization. That we are able to successfully do this directly demonstrates that renormalizability need not be a fundamental requirement for all physically viable models.
Research in theoretical particle physics. Technical progress report, May 1, 1991--April 30, 1992
McKay, D.W.; Munczek, H.; Ralston, J.
1992-05-01
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)
Quasi-Particles in Conformal Field Theories for Fractional Quantum Hall Systems
NASA Astrophysics Data System (ADS)
Schoutens, K.; van Elburg, R. A. J.
2001-09-01
We briefly summarize the contents of lectures presented at the Fourth APCTP Winter School on Integrable Quantum Field Theories and Applications. A central theme in these lectures were quasi-particle formulations of edge theories for fractional quantum Hall systems. We explained a formal connection with models of quantum mechanics with inverse square exchange, and presented explicit results for form factors that describe processes where physical electrons tunnel into the edge of a fractional quantum Hall system.
The dialogue between particle physics and cosmology
Sadoulet, B.
1988-04-01
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.
Particle Physics on the Eve of Lhc
NASA Astrophysics Data System (ADS)
Studenikin, Alexander I.
2009-01-01
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 physics. Collective effects in central heavy-ion collisions / G. I. Lykasov ... [et al.]. Stringy phenomena in Yang-Mills plasma / V. I. Zakharov. Lattice results on gluon and ghost propagators in Landau gauge / I. L. Bogolubsky ... [et al.]. [symbol] and [symbol] excited states in field correlator method / I. Narodetskii, A. Veselov. Theory of quark-gluon plasma and phase transition / E. V. Komarov, Yu. A. Simonov. Chiral symmetry breaking and the Lorentz nature of confinement / A. V. Nefediev. Structure function moments of proton and neutron / M. Osipenko. Higgs decay to bb: different approaches to resummation of QCD effects / A. L. Kataev, V. T. Kim. A novel integral representation for the Adler function and its behavior at low energies / A. V. Nesterenko. QCD test of z-scaling for [symbol]-meson production in pp collisions at high energies / M. Tokarev, T. Dedovich. Quark mixing in the standard model and the space rotations / G. Dattoli, K. Zhukovsky. Analytic approach to constructing effective theory of strong interactions and its application to pion-nucleon scattering / A. N. Safronov -- New developments in quantum field theory. On the origin of families and their mass matrices with the approach unifying spin and charges, prediction for new families / N. S. Mankoc Borstnik. Z[symbol] electric strings and center vortices in SU(2) lattice gauge theory / M. I. Polikarpov, P. V. Buividovich. Upper bound on the lightest neutralino mass in the minimal non-minimal supersymmetric standard model / S. Hesselbach ... [et al.]. Application of higher derivative regularization to calculation of quantum corrections in N=l supersymmetric theories / K. Stepanyantz. Nonperturbative quantum relativistic effects in the confinement mechanism for particles in a deep potential well / K. A. Sveshnikov, M. V. Ulybyshev. Khalfin's theorem and neutral mesons subsystem / K. Urbanowski. Effective lagrangians and field theory on a lattice / O. V. Pavlovsky. String-like electrostatic interaction from QED with infinite magnetic field / A. E. Shabad, V. V. Usov. QFT systems with 2D spatial defects / I. V. Fialkovsky, V. N. Markov, Yu. M. Pismak. Bound state problems and radiative effects in extended electrodynamics with Lorentz violation / I. E. Frolov, O. G. Kharlanov, V. Ch. Zhukovsky. Particles with low binding energy in a strong stationary magnetic field / E. V. Arbuzova, G. A. Kravtsova, V. N. Rodionov. Triangle anomaly and radiatively induced Lorentz and CPT violation in electrodynamics / A. E. Lobanov, A. P. Venediktov. The comparative analysis of the angular distribution of synchrotron radiation for a spinless particle in classic and quantum theories / V. G. Bagrov, A. N. Burimova, A. A. Gusev. Problem of the spin light identification / V. A. Bordovitsyn, V. V. Telushkin. Simulation the nuclear interaction / T. F. Kamalov. Unstable leptons and (u - e - [symbol])-universality / O. Kosmachev. Generalized Dirac equation describing the quark structure of nucleons / A. Rabinowitch. Unique geometrization of material and electromagnetic wave fields / O. Olkhov -- Problems of intelligentsia. The conscience of the intelligentsia / J. K. Bleimaier.
Elementary particle physics---Experimental
Lord, J.J.; Burnett, T.H.; Wilkes, R.J.
1990-09-20
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.
A signed particle formulation of non-relativistic quantum mechanics
Sellier, Jean Michel
2015-09-15
A formulation of non-relativistic quantum mechanics in terms of Newtonian particles is presented in the shape of a set of three postulates. In this new theory, quantum systems are described by ensembles of signed particles which behave as field-less classical objects which carry a negative or positive sign and interact with an external potential by means of creation and annihilation events only. This approach is shown to be a generalization of the signed particle Wigner Monte Carlo method which reconstructs the time-dependent Wigner quasi-distribution function of a system and, therefore, the corresponding Schrödinger time-dependent wave-function. Its classical limit is discussed and a physical interpretation, based on experimental evidences coming from quantum tomography, is suggested. Moreover, in order to show the advantages brought by this novel formulation, a straightforward extension to relativistic effects is discussed. To conclude, quantum tunnelling numerical experiments are performed to show the validity of the suggested approach.
Studies in theoretical particle physics
Kaplan, D.B.
1991-07-01
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.
Quantum circuit physical design methodology with emphasis on physical synthesis
NASA Astrophysics Data System (ADS)
Mohammadzadeh, Naser; Saheb Zamani, Morteza; Sedighi, Mehdi
2013-11-01
In our previous works, we have introduced the concept of "physical synthesis" as a method to consider the mutual effects of quantum circuit synthesis and physical design. While physical synthesis can involve various techniques to improve the characteristics of the resulting quantum circuit, we have proposed two techniques (namely gate exchanging and auxiliary qubit selection) to demonstrate the effectiveness of the physical synthesis. However, the previous contributions focused mainly on the physical synthesis concept, and the techniques were proposed only as a proof of concept. In this paper, we propose a methodological framework for physical synthesis that involves all previously proposed techniques along with a newly introduced one (called auxiliary qubit insertion). We will show that the entire flow can be seen as one monolithic methodology. The proposed methodology is analyzed using a large set of benchmarks. Experimental results show that the proposed methodology decreases the average latency of quantum circuits by about 36.81 % for the attempted benchmarks.
Teaching Elementary Particle Physics: Part I
ERIC Educational Resources Information Center
Hobson, Art
2011-01-01
I'll outline suggestions for teaching elementary particle physics, often called "high energy physics," in high school or introductory college courses for non-scientists or scientists. Some presentations of this topic simply list the various particles along with their properties, with little overarching structure. Such a laundry list approach is a
Quarked!--Adventures in Particle Physics Education
ERIC Educational Resources Information Center
MacDonald, Teresa; Bean, Alice
2009-01-01
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
Particle Physics: From School to University.
ERIC Educational Resources Information Center
Barlow, Roger
1992-01-01
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)
Quarked!--Adventures in Particle Physics Education
ERIC Educational Resources Information Center
MacDonald, Teresa; Bean, Alice
2009-01-01
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…
Teaching Elementary Particle Physics: Part I
ERIC Educational Resources Information Center
Hobson, Art
2011-01-01
I'll outline suggestions for teaching elementary particle physics, often called "high energy physics," in high school or introductory college courses for non-scientists or scientists. Some presentations of this topic simply list the various particles along with their properties, with little overarching structure. Such a laundry list approach is a…
Heim Quantum Theory for Space Propulsion Physics
NASA Astrophysics Data System (ADS)
Drscher, Walter; Huser, Jochem
2005-02-01
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 a completely different type of propulsion, denoted gravitophoton field propulsion. The fifth interaction, termed gravitophoton force, would accelerate a material body without the need of propellant. Gravitophoton interaction is a gravitational like force, mediated by gravitophoton particles that come in both types, attractive and repulsive. Gravitophoton particles are generated in pairs from the vacuum itself by the effect of vacuum polarization (virtual electrons), under the presence of a very strong magnetic field (photons). Due to gravitophoton pair production, the total energy extracted from the vacuum is zero. Attractive gravitophotons interact with matter, and thus can become real particles, exacting a force on a material body. Repulsive gravitophotons have a much smaller cross section and do not interact with matter. Consequently, the kinetic energy of the accelerated material body would come from the vacuum, satisfying the second condition, i.e., a low energy budget for space propulsion. The name gravitophoton has been chosen because a transformation of photons into gravitational energy should take place. The third condition for advanced spaceflight, superluminal speed, may be realized by transition into a parallel space, in which covariant laws of physics are valid, with a limiting speed of light nc, where n is an integer and c is the vacuum speed of light. In order to achieve such a transition, the sixth fundamental interaction would be needed, termed vacuum field (or quintessence), which is a weakly repulsive gravitational like force, mediated by the vacuum particle, being formed by the interaction of repulsive gravitophotons with the gravitons of the spacecraft. The paper discusses the source of the two predicted interactions, the concept of parallel space, and presents the physical model along with an experimental setup to measure and estimate the gravitophoton force. Estimates for the magnitude of magnetic fields are presented, and trip times for lunar and Mars missions are given.
Beyond relativity and quantum mechanics: space physics
NASA Astrophysics Data System (ADS)
Lindner, Henry H.
2011-09-01
Albert Einstein imposed an observer-based epistemology upon physics. Relativity and Quantum Mechanics limit physics to describing and modeling the observer's sensations and measurements. Their "underlying reality" consists only of ideas that serve to model the observer's experience. These positivistic models cannot be used to form physical theories of Cosmic phenomena. To do this, we must again remove the observer from the center of physics. When we relate motion to Cosmic space instead of to observers and we attempt to explain the causes of Cosmic phenomena, we are forced to admit that Cosmic space is a substance. We need a new physics of space. We can begin by replacing Relativity with a modified Lorentzian-Newtonian model of spatial flow, and Quantum Mechanics with a wave-based theory of light and electrons. Space physics will require the reinterpretation of all known phenomena, concepts, and mathematical models.
The Physical Renormalization of Quantum Field Theories
Binger, Michael William.; /Stanford U., Phys. Dept. /SLAC
2007-02-20
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.
[Elementary particle physics. Annual report
Izen, J.M.; Lou, X.
1998-12-31
The BABAR construction phase is ending and first data is expected during May, 1999. During construction, UTD has developed analysis framework software, contributed to the BABAR Physics Book, assembled a first rate computing facility, and pioneered Internet-based video techniques for the collaboration. The authors are now defining the physics goals, and are participating in the formation physics analysis groups. They are starting to use their computing facility for BABAR production jobs.
Thermal equilibrium of two quantum Brownian particles
Valente, D. M.; Caldeira, A. O.
2010-01-15
The influence of the environment in the thermal equilibrium properties of a bipartite continuous variable quantum system is studied. The problem is treated within a system-plus-reservoir approach. The considered model reproduces the Brownian motion when the two particles are isolated and induces an effective interaction between them, depending on the choice of the spectral function of the bath. The coupling between the system and the environment guarantees the translational invariance of the system in the absence of an external potential. The entanglement between the particles is measured by the logarithmic negativity, which is shown to monotonically decrease with the increase of the temperature. A range of finite temperatures is found in which entanglement is still induced by the reservoir.
An Introduction to Neutrosophic Probability Applied in Quantum Physics
NASA Astrophysics Data System (ADS)
Smarandache, Florentin
2009-05-01
In this paper we generalizes the classical probability and imprecise probability to the notion of neutrosophic probability in order to be able to model Heisenberg's Uncertainty Principle of a particle's behavior, Schr"odinger's Cat Theory, and the state of bosons which do not obey Pauli's Exclusion Principle (in quantum physics). Neutrosophic probability is close related to neutrosophic logic and neutrosophic set, and etymologically derived from neutrosophy.
Development of quantum perspectives in modern physics
NASA Astrophysics Data System (ADS)
Baily, Charles; Finkelstein, Noah D.
2009-06-01
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.
Effective quantum dynamics of two Brownian particles
NASA Astrophysics Data System (ADS)
Duarte, O. S.; Caldeira, A. O.
2009-09-01
We use the system-plus-reservoir approach to study the quantum dynamics of a bipartite continuous variable system (two generic particles). We present an extension of the traditional model of a bath of oscillators which is capable of inducing an effective coupling between the two parts of the system depending on the choice made for the spectral density of the bath. The coupling is nonlinear in the system variables and an exponential dependence on these variables is imposed in order to guarantee the translational invariance of the model if the two particles are not subject to any external potential. The reduced density operator is obtained by the functional integral method. The dynamical susceptibility of the reservoir is modeled in order to introduce, besides a characteristic frequency, a characteristic length that determines if the effective interaction potential is strong enough to induce entanglement between the particles. Our model provides a criterion of distance for identifying in which cases a common environment can induce entanglement. Three regimes are found: the short distance regime, equivalent to a bilinear system-reservoir coupling, the long distance regime in which the particles act like coupled to independent reservoirs, and the intermediate regime suitable for the competition between decoherence and induced entanglement.
Frontiers of particle beam physics
Sessler, A.M.
1989-11-01
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.
ERIC Educational Resources Information Center
Ellison, Mark D.
2008-01-01
The one-dimensional particle-in-a-box model used to introduce quantum mechanics to students suffers from a tenuous connection to a real physical system. This article presents a two-dimensional model, the particle confined within a ring, that directly corresponds to observations of surface electrons in a metal trapped inside a circular barrier.
ERIC Educational Resources Information Center
Ellison, Mark D.
2008-01-01
The one-dimensional particle-in-a-box model used to introduce quantum mechanics to students suffers from a tenuous connection to a real physical system. This article presents a two-dimensional model, the particle confined within a ring, that directly corresponds to observations of surface electrons in a metal trapped inside a circular barrier.…
A quantum anomaly for rigid particles
NASA Astrophysics Data System (ADS)
Govaerts, Jan
1992-10-01
Canonical quantisation of rigid particles is considered paying special attention to the restriction on phase space due to causal propagation. A mixed Lorentz-gravitational anomaly is found in the commutator of Lorentz boosts with world-line reparametrisations. The subspace of gauge invariant physical states is therefore not invariant under Lorentz transformations. The analysis applies for an arbitrary extrinsic curvature dependence with exception of only one case to be studied separately. Consequences for rigid strings are also discussed.
Theoretical particle physics. Progress report, FY 1993
Not Available
1993-09-30
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.
Rutherford's Legacy in Particle Physics
NASA Astrophysics Data System (ADS)
Friedman, Jerome I.
2011-04-01
Rutherford's legacy of employing scattering experiments to probe structure has been crucial to advancing our understanding of sub-atomic physics. This talk will describe the role of inelastic electron and neutrino scattering in uncovering the quark sub-structures of the proton and neutron.
Unification of quantum theory and classical physics
Stapp, H.P.
1985-07-01
A program is described for unifying quantum theory and classical physics on the basis of the Copenhagen-interpretation idea of external reality and a recently discovered classical part of the electromagnetic field. The program effects an integration of the intuitions of Heisenberg, Bohr, and Einstein.
Quantum Inferential Leaps: The Rhetoric of Physics.
ERIC Educational Resources Information Center
McPhail, Mark Lawrence
1992-01-01
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).…
Quantum chaos and thermalization in isolated systems of interacting particles
NASA Astrophysics Data System (ADS)
Borgonovi, F.; Izrailev, F. M.; Santos, L. F.; Zelevinsky, V. G.
2016-04-01
This review is devoted to the problem of thermalization in a small isolated conglomerate of interacting constituents. A variety of physically important systems of intensive current interest belong to this category: complex atoms, molecules (including biological molecules), nuclei, small devices of condensed matter and quantum optics on nano- and micro-scale, cold atoms in optical lattices, ion traps. Physical implementations of quantum computers, where there are many interacting qubits, also fall into this group. Statistical regularities come into play through inter-particle interactions, which have two fundamental components: mean field, that along with external conditions, forms the regular component of the dynamics, and residual interactions responsible for the complex structure of the actual stationary states. At sufficiently high level density, the stationary states become exceedingly complicated superpositions of simple quasiparticle excitations. At this stage, regularities typical of quantum chaos emerge and bring in signatures of thermalization. We describe all the stages and the results of the processes leading to thermalization, using analytical and massive numerical examples for realistic atomic, nuclear, and spin systems, as well as for models with random parameters. The structure of stationary states, strength functions of simple configurations, and concepts of entropy and temperature in application to isolated mesoscopic systems are discussed in detail. We conclude with a schematic discussion of the time evolution of such systems to equilibrium.
Research on elementary particle physics
Holloway, L.E.; O'Halloran, T.A.
1992-05-01
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.
Research in Theoretical Particle Physics
Ralston, John P.
2013-07-28
This document is the final report on activity of the University of Kansas theory group supported under DOE Grant Number DE-FG02-04ER14308, ending April 30, 3013. The report covers the most recent three year period period May 1, 2010-April 30, 2013. Faculty supported by the grant during the period were Danny Marfatia (co-I), Douglas McKay (emeritus) and John Ralston (PI). The group's research topics and accomplishments covered numerous different topics subsumed under the {\\it the Energy Frontier, the Intensity Frontier}, and {\\it the Cosmic Frontier}. Many theoretical and experimental results related to the Standard Model and models of new physics were published during the reporting period. The group's research emphasis has been on challenging and confronting {\\it Anything that is Observable} about the physical Universe.
Theoretical particle physics, Task A
Not Available
1991-07-01
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.
Particle transport and deposition: basic physics of particle kinetics
Tsuda, Akira; Henry, Frank S.; Butler, James P.
2015-01-01
The human body interacts with the environment in many different ways. The lungs interact with the external environment through breathing. The enormously large surface area of the lung with its extremely thin air-blood barrier is exposed to particles suspended in the inhaled air. Whereas the particle-lung interaction may cause deleterious effects on health if the inhaled pollutant aerosols are toxic, this interaction can be beneficial for disease treatment if the inhaled particles are therapeutic aerosolized drug. In either case, an accurate estimation of dose and sites of deposition in the respiratory tract is fundamental to understanding subsequent biological response, and the basic physics of particle motion and engineering knowledge needed to understand these subjects is the topic of this chapter. A large portion of this chapter deals with three fundamental areas necessary to the understanding of particle transport and deposition in the respiratory tract. These are: 1) the physical characteristics of particles, 2) particle behavior in gas flow, and 3) gas flow patterns in the respiratory tract. Other areas, such as particle transport in the developing lung and in the diseased lung are also considered. The chapter concludes with a summary and a brief discussion of areas of future research. PMID:24265235
Quantum tunneling of light particles in metals
NASA Astrophysics Data System (ADS)
Grabert, H.; Weiss, U.; Schober, H. R.
1986-12-01
The motion of a particle in a metallic crystal is studied for low temperatures where transitions between adjacent interstitial sites are caused by quantum tunneling. The influence of electrons and phonons on the hopping rate is taken into account by means of a functional integral method. The electronic influence may effectively be described by Ohmic damping which dominates the low temperature behavior of the defect motion. When subsequent tunneling transitions are statistically independent, the diffusion constant is found to obey a power law, D˜T2K-1, where K depends on the defect-electron interaction. This power law is limited at low temperatures by the effects of phonon excitations. Near the transition between electron and phonon dominated behavior the diffusion constant has a minimum where the precise temperature dependence of the rate depends not only on phonon spectra but also on the processes limiting phonon lifetimes.
Quantum physics reimagined for the general public
NASA Astrophysics Data System (ADS)
Bobroff, Julien
2015-03-01
Quantum Physics has always been a challenging issue for outreach. It is invisible, non-intuitive and written in sophisticated mathematics. In our ``Physics Reimagined'' research group, we explore new ways to present that field to the general public. Our approach is to develop close collaborations between physicists and designers or graphic artists. By developing this new kind of dialogue, we seek to find new ways to present complex phenomena and recent research topics to the public at large. For example, we created with web-illustrators a series of 3D animations about basic quantum laws and research topics (graphene, Bose-Einstein condensation, decoherence, pump-probe techniques, ARPES...). We collaborated with designers to develop original setups, from quantum wave animated models or foldings to a superconducting circus with levitating animals. With illustrators, we produced exhibits, comic strips or postcards displaying the physicists in their labs, either famous ones or even our own colleagues in their daily life as researchers. With artists, we recently made a stop-motion picture to explain in an esthetic way the process of discovery and scientific publication. We will discuss how these new types of outreach projects allowed us to engage the public with modern physics both on a scientific and cultural level and how the concepts and process can easily be replicated and expanded by other physicists. We are at the precise time when creative tools, interfaces, and ways of sharing and learning are rapidly evolving (wikipedia, MOOCs, smartphones...). If scientists don't step forward to employ these tools and develop new resources, other people will, and the integrity of the science and underlying character of research risks being compromised. All our productions are free to use and can be downloaded at www.PhysicsReimagined.com (for 3D quantum videos, specific link: www.QuantumMadeSimple.com) This work benefited from the support of the Chair ``Physics Reimagined'' (Paris-Sud University/Air Liquide).
Counting statistics of many-particle quantum walks
Mayer, Klaus; Tichy, Malte C.; Buchleitner, Andreas; Mintert, Florian; Konrad, Thomas
2011-06-15
We study quantum walks of many noninteracting particles on a beam splitter array as a paradigmatic testing ground for the competition of single- and many-particle interference in a multimode system. We derive a general expression for multimode particle-number correlation functions, valid for bosons and fermions, and infer pronounced signatures of many-particle interferences in the counting statistics.
Symmetry, conservation laws, and theoretical particle physics
NASA Astrophysics Data System (ADS)
Krumins, Andris Visvaldis
In this work, we trace the role of symmetry throughout the history of theoretical particle physics, paying particular attention to the role of group theory, the formal mathematics of symmetry. After an analysis of the role of conservation laws and invariance in the theory of general relativity, we move on to Weyl's gauge theory of 1918, which was developed within the context of general relativity as an attempt to unify gravitation and electromagnetism. Weyl was trying to exploit an invariance of scale, and although his theory was experimentally refuted, it provided a formulation of the conservation of charge. After the advent of quantum mechanics, gauge theory was reinterpreted by London as an invariance of the wave-function. Weyl and Wigner studied group theory in the context of quantum mechanics, but the broadness of its application had yet to be appreciated. Symmetry was soon exploited in the nuclear interactions, however, and we examine the events leading to the discovery of SU(2) of isotopic spin. We analyze how the discovery of strangeness was linked to the generalization of SU(2) to SU(3), and also how it led to a differentiation between the strong interactions, which conserve isotopic spin and strangeness, and the weak interactions, which violate these conservation laws, along with the conservation of parity. Yang and Mills were impressed with gauge invariance, and in 1954, they took the bold step of imposing it upon the Lagrangian of the strong interactions, forcing the introduction of three new gauge fields. There was a problem, however, because although the short-range of the strong interactions implied that these gauge bosons should be massive, they needed to be massless in order to preserve gauge invariance. In addition, efforts were made to extend Yang-Mills theory to the weak interactions, but they also faced the same zero-mass problem. This problem was finally solved in 1967, when Weinberg and Salam showed how gauge boson masses could be generated using spontaneous symmetry breaking. They based a unification of the electromagnetic and weak interactions upon local gauge invariance, and this principle was soon applied to the strong interactions as well.
Physics on the boundary between classical and quantum mechanics
NASA Astrophysics Data System (ADS)
't Hooft, Gerard
2014-04-01
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?
Nuclear and Particle Physics Simulations: The Consortium of Upper-Level Physics Software
NASA Astrophysics Data System (ADS)
Bigelow, Roberta; Moloney, Michael J.; Philpott, John; Rothberg, Joseph
1995-06-01
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.
High Intensity Particle Physics at PW-class laser facilities
NASA Astrophysics Data System (ADS)
Bulanov, Stepan; Schroeder, Carl; Esarey, Eric; Esirkepov, Timur; Kando, Masaki; Rosanov, Nikolay; Korn, Georg; Bulanov, Sergey V.; Leemans, Wim P.
2015-11-01
The processes typical for high intensity particle physics, i.e., the interactions of charged particles with strong electromagnetic fields, have attracted considerable interest recently. Some of these processes, previously believed to be of theoretical interest only, are now becoming experimentally accessible. High intensity electromagnetic (EM) fields significantly modify the interactions of particles and EM fields, giving rise to the phenomena that are not encountered either in classical or perturbative quantum theory of these interactions. One of such phenomena is the radiation reaction, which radically influences the electron motion in an electromagnetic standing wave formed by two super-intense counter-propagating laser pulses. Depending on the laser intensity and wavelength, either classical or quantum mode of radiation reaction prevail, or both are strong. When radiation reaction dominates, electron motion evolves to limit cycles and strange attractors. This creates a new framework for high energy physics experiments on an interaction of energetic charged particle beams and colliding super-intense laser pulses. Work supported by U.S. DOE under Contract No. DE-AC02-05CH11231.
On the photoelectric quantum yield of small dust particles
NASA Astrophysics Data System (ADS)
Kimura, Hiroshi
2016-04-01
Photoelectron emission is crucial to electric charging of dust particles around main-sequence stars and gas heating in various dusty environments. An estimate of the photoelectric processes contains an ill-defined parameter called the photoelectric quantum yield, which is the total number of electrons ejected from a dust particle per absorbed photon. Here we revisit the so-called small particle effect of photoelectron emission and provide an analytical model to estimate photoelectric quantum yields of small dust particles in sizes down to nanometers. We show that the small particle effect elevates the photoelectric quantum yields of nanoparticles up to by a factor of 103 for carbon, water ice, and an organics, and a factor of 102 for silicate, silicon carbide, and iron. We conclude the surface curvature of the particles is a quantity of great importance to the small particle effect, unless the particles are submicrometers in radius or larger.
Plato's TIMAIOσ (TIMAEUS) and Modern Particle Physics
NASA Astrophysics Data System (ADS)
Machleidt, Ruprecht
2005-04-01
It is generally known that the question, ``What are the smallest particles (elementary particles) that all matter is made from?'', was posed already in the antiquity. The Greek natural philosophers Leucippus and Democritus were the first to suggest that all matter was made from atoms. Therefore, most people perceive them as the ancient fathers of elementary particle physics. It will be the purpose of my contribution to point out that this perception is wrong. Modern particle physics is not just a primitive atomism. More important than the materialistic particles are the underlying symmetries (e. g., SU(3) and SU(6)). A similar idea was first advanced by Plato in his dialog TIMAIOσ (Latin translation: TIMAEUS): Geometric symmetries generate the materialistic particles from a few even more elementary items. Plato's vision is amazingly close to the ideas of modern particle physics. This fact, which is unfortunately little known, has been pointed out repeatedly by Heisenberg (see, e. g., Werner Heisenberg, Across the Frontiers, Harper & Row, New York, 1974).
Elementary particle physics at the University of Florida
Not Available
1991-12-01
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).
Flavor Democracy in Particle Physics
NASA Astrophysics Data System (ADS)
Sultansoy, Saleh
2007-04-01
The flavor democracy hypothesis (or, in other words, democratic mass matrix approach) was introduced in seventies taking in mind three Standard Model (SM) families. Later, this idea was disfavored by the large value of the t-quark mass. In nineties the hypothesis was revisited assuming that extra SM families exist. According to flavor democracy the fourth SM family should exist and there are serious arguments disfavoring the fifth SM family. The fourth SM family quarks lead to essential enhancement of the Higgs boson production cross-section at hadron colliders and the Tevatron can discover the Higgs boson before the LHC, if it mass is between 140 and 200 GeV. Then, one can handle ``massless'' Dirac neutrinos without see-saw mechanism. Concerning BSM physics, flavor democracy leads to several consequences: tanβ ~ mt/mb ~ 40 if there are three MSSM families; super-partner of the right-handed neutrino can be the LSP; relatively light E(6)-inspired isosinglet quark etc. Finally, flavor democracy may give opportunity to handle ``massless'' composite objects within preonic models.
Pragmatic versus semantic contextuality in quantum physics
NASA Astrophysics Data System (ADS)
Garola, Claudio
1995-08-01
An approach to quantum physics (QP) is proposed that is characterized by the attempt to give up the verificationist theory of truth underlying the standard interpretation of QP. As a first step, an observatively minimal language L is constructed that is endowed with a Tarskian truth theory. Then, a set of axioms is stated by means of L that hold both in classical physics and in QP, and the further language Le of all properties is constructed. The concepts of meaning and testability do not collapse in L and Le, hence quantum logic is interpreted as a theory of testability in QP, and QP turns out to be semantically incomplete. Furthermore, semantic and pragmatic compatibility of physical properties are distinguished in Le, and the concepts of testability and conjoint testability of statements are introduced. In this context some known quantum paradoxes can be avoided, and a new general principle (MGP) characterizes the truth mode of empirical physical laws. MGP invalidates the Bell theorem and, presumably, the Bell-Kochen-Specker theorem, and introduces a pragmatic contextuality in QP in place of the semantic contextuality that should occur because of these theorems.
Research in Theoretical Particle Physics
Feldman, Hume A; Marfatia, Danny
2014-09-24
This document is the final report on activity supported under DOE Grant Number DE-FG02-13ER42024. The report covers the period July 15, 2013 – March 31, 2014. Faculty supported by the grant during the period were Danny Marfatia (1.0 FTE) and Hume Feldman (1% FTE). The grant partly supported University of Hawaii students, David Yaylali and Keita Fukushima, who are supervised by Jason Kumar. Both students are expected to graduate with Ph.D. degrees in 2014. Yaylali will be joining the University of Arizona theory group in Fall 2014 with a 3-year postdoctoral appointment under Keith Dienes. The group’s research covered topics subsumed under the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. Many theoretical results related to the Standard Model and models of new physics were published during the reporting period. The report contains brief project descriptions in Section 1. Sections 2 and 3 lists published and submitted work, respectively. Sections 4 and 5 summarize group activity including conferences, workshops and professional presentations.
Basics of particle therapy I: physics
Park, Seo Hyun
2011-01-01
With the advance of modern radiation therapy technique, radiation dose conformation and dose distribution have improved dramatically. However, the progress does not completely fulfill the goal of cancer treatment such as improved local control or survival. The discordances with the clinical results are from the biophysical nature of photon, which is the main source of radiation therapy in current field, with the lower linear energy transfer to the target. As part of a natural progression, there recently has been a resurgence of interest in particle therapy, specifically using heavy charged particles, because these kinds of radiations serve theoretical advantages in both biological and physical aspects. The Korean government is to set up a heavy charged particle facility in Korea Institute of Radiological & Medical Sciences. This review introduces some of the elementary physics of the various particles for the sake of Korean radiation oncologists' interest. PMID:22984664
Basics of particle therapy I: physics.
Park, Seo Hyun; Kang, Jin Oh
2011-09-01
With the advance of modern radiation therapy technique, radiation dose conformation and dose distribution have improved dramatically. However, the progress does not completely fulfill the goal of cancer treatment such as improved local control or survival. The discordances with the clinical results are from the biophysical nature of photon, which is the main source of radiation therapy in current field, with the lower linear energy transfer to the target. As part of a natural progression, there recently has been a resurgence of interest in particle therapy, specifically using heavy charged particles, because these kinds of radiations serve theoretical advantages in both biological and physical aspects. The Korean government is to set up a heavy charged particle facility in Korea Institute of Radiological & Medical Sciences. This review introduces some of the elementary physics of the various particles for the sake of Korean radiation oncologists' interest. PMID:22984664
Quarked! - Adventures in Particle Physics Education
NASA Astrophysics Data System (ADS)
MacDonald, Teresa; Bean, Alice
2009-01-01
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 introduced until high school or university.1,2 Many of these concepts can be made accessible to younger students when presented in a fun and engaging way. Informal science institutions are in an ideal position to communicate new and challenging science topics in engaging and innovative ways and offer a variety of educational enrichment experiences for students that support and enhance science learning.3 Quarked!™ Adventures in the Subatomic Universe, a National Science Foundation EPSCoR-funded particle physics education program, provides classroom programs and online educational resources.
Quantum Gravity Corrections to the Tunneling Radiation of Scalar Particles
NASA Astrophysics Data System (ADS)
Wang, Peng; Yang, Haitang; Ying, Shuxuan
2016-01-01
The original derivation of Hawking radiation shows the complete evaporation of black holes. However, theories of quantum gravity predict the existence of the minimal observable length. In this paper, we investigate the tunneling radiation of the scalar particles by introducing the quantum gravity effects influenced by the generalized uncertainty principle. The Hawking temperatures are not only determined by the properties of the black holes, but also affected by the quantum numbers of the emitted particles. The quantum gravity corrections slow down the increase of the temperatures. The remnants are found during the evaporation.
Quantum Gravity Corrections to the Tunneling Radiation of Scalar Particles
NASA Astrophysics Data System (ADS)
Wang, Peng; Yang, Haitang; Ying, Shuxuan
2016-05-01
The original derivation of Hawking radiation shows the complete evaporation of black holes. However, theories of quantum gravity predict the existence of the minimal observable length. In this paper, we investigate the tunneling radiation of the scalar particles by introducing the quantum gravity effects influenced by the generalized uncertainty principle. The Hawking temperatures are not only determined by the properties of the black holes, but also affected by the quantum numbers of the emitted particles. The quantum gravity corrections slow down the increase of the temperatures. The remnants are found during the evaporation.
NASA Astrophysics Data System (ADS)
Alekseev, Vladimir A.
2001-01-01
The distribution function ω0(n0) of the number n0 of particles in the condensate of an ideal Bose gas confined by a trap is found. It is shown that at the temperature above the critical one (T > Tc) this function has the usual form ω0(n0) =(1 — eμ)eμno, where μ is the chemical potential in the temperature units. For T < Tc, this distribution changes almost in a jump to a Gaussian distribution, which depends on the trap potential only parametrically. The centre of this function shifts to larger values of n0 with decreasing temperature and its width tends to zero, which corresponds to the suppression of fluctuations.
The Coming Revolutions in Particle Physics
NASA Astrophysics Data System (ADS)
Quigg, Chris
2006-12-01
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.
Two-dimensional topological order of kinetically constrained quantum particles
NASA Astrophysics Data System (ADS)
Kourtis, Stefanos
2015-03-01
Motivated by recent experimental and theoretical work on driven optical lattices, we investigate how imposing kinetic restrictions on quantum particles that would otherwise hop freely on a two-dimensional lattice can lead to topologically ordered states. The kinetically constrained models introduced here are derived as an approximate generalization of strongly interacting particles hopping on Haldane and equivalent lattices and are pertinent to systems irradiated by circularly polarized light. After introducing a broad class of models, we focus on particular realizations and show numerically that they exhibit topological order, by observing topological ground-state degeneracies and the quantization of corresponding invariants. Apart from potentially being crucial for the interpretation of forthcoming cold-atom experiments, our results also hint at unexplored possibilities for the realization of topologically ordered matter. A further implication, relevant to fractional quantum Hall (FQH) physics, is that the correlations responsible for FQH-like states can arise from processes other than density-density interactions. Financial support from EPSRC (Grant No. EP/K028960/1) and ICAM Branch Contributions.
Particle Physics Outreach to Secondary Education
Bardeen, Marjorie G.; Johansson, K.Erik; Young, M.Jean
2011-11-21
This review summarizes exemplary secondary education and outreach programs of the particle physics community. We examine programs from the following areas: research experiences, high-energy physics data for students, informal learning for students, instructional resources, and professional development. We report findings about these programs' impact on students and teachers and provide suggestions for practices that create effective programs from those findings. We also include some methods for assessing programs.
Japanese particle-physics leader dies
NASA Astrophysics Data System (ADS)
Durrani, Matin
2008-08-01
Yoji Totsuka, former director general of the KEK particle-physics lab in Japan, died on 10 July at the age of 66. Totsuka, whose research interests were in the field of neutrino physics, served as KEK boss for three years from April 2003. After retiring in 2006, Totsuka became a professor emeritus at KEK and the University of Tokyo. His funeral on 12 July was attended by more than 500 people.
PREFACE: Particles and Fields: Classical and Quantum
NASA Astrophysics Data System (ADS)
Asorey, M.; Clemente-Gallardo, J.; Marmo, G.
2007-07-01
This volume contains some of the contributions to the Conference Particles and Fields: Classical and Quantum, which was held at Jaca (Spain) in September 2006 to honour George Sudarshan on his 75th birthday. Former and current students, associates and friends came to Jaca to share a few wonderful days with George and his family and to present some contributions of their present work as influenced by George's impressive achievements. This book summarizes those scientific contributions which are presented as a modest homage to the master, collaborator and friend. At the social ceremonies various speakers were able to recall instances of his life-long activity in India, the United States and Europe, adding colourful remarks on the friendly and intense atmosphere which surrounded those collaborations, some of which continued for several decades. This meeting would not have been possible without the financial support of several institutions. We are deeply indebted to Universidad de Zaragoza, Ministerio de Educación y Ciencia de España (CICYT), Departamento de Ciencia, Tecnología y Universidad del Gobierno de Aragón, Universitá di Napoli 'Federico II' and Istituto Nazionale di Fisica Nucleare. Finally, we would like to thank the participants, and particularly George's family, for their contribution to the wonderful atmosphere achieved during the Conference. We would like also to acknowledge the authors of the papers collected in the present volume, the members of the Scientific Committee for their guidance and support and the referees for their generous work. M Asorey, J Clemente-Gallardo and G Marmo The Local Organizing Committee George Sudarshan
A. Ashtekhar (Pennsylvania State University, USA) |
L. J. Boya (Universidad de Zaragoza, Spain) |
I. Cirac (Max Planck Institute, Garching, Germany) |
G. F. Dell Antonio (Universitá di Roma La Sapienza, Italy) |
A. Galindo (Universidad Complutense de Madrid, Spain) |
S. L. Glashow (Boston University, USA) |
A. M. Gleeson (University of Texas, Austin, USA) |
C. R. Hagen (Rochester University, NY, USA) |
J. Klauder (University of Florida, Gainesville, USA) |
A. Kossakowski (University of Torun, Poland) |
V.I. Manko (Lebedev Physical Institute, Moscow, Russia) |
G. Marmo (Universitá Federico II di Napoli e INFN Sezione di Napoli, Italy) |
N. Mukunda (Indian Institute of Science, Bangalore, India) |
J. V. Narlikar (Inter-University Centre for Astronomy and Astrophysics, Pune, India) |
J. Nilsson (University of Goteborg, Sweden) |
S. Okubo (Rochester University, NY, USA) |
T. Regge (Politecnico di Torino, Italy) |
W. Schleich (University of Ulm, Germany) |
M. Scully (Texas A& M University, USA) |
S. Weinberg (University of Texas, Austin, USA) |
M. Asorey (Universidad de Zaragoza, Spain) |
L. J. Boya (Universidad de Zaragoza, Spain). Co-Chair |
J. F. Cariñena (Universidad de Zaragoza, Spain) |
J. Clemente-Gallardo (Universidad de Zaragoza, Spain) |
F. Falceto (Universidad de Zaragoza, Spain) |
G. Marmo (Universitá Federico II di Napoli e INFN Sezione di Napoli, Italy) Co-Chair |
G. Morandi (Universitá di Bologna, Italy) |
ACHARYA, Raghunath: Arizona State University, USA |
AGUADO, Miguel M.: Max-Planck-Institut für Quantenoptik, Garching, Germany |
ASOREY, Manuel: Universidad de Zaragoza, Spain |
BERETTA, Gian Paolo: Università di Brescia, Italy |
BHAMATHI, Gopalakrishnan: University of Texas at Austin, USA |
BOYA, Luis Joaquín: Universidad de Zaragoza, Spain |
CARIÑENA, José F.: Universidad de Zaragoza, Spain |
CELEGHINI, Enrico: Università di Firenze & INFN, Italy |
CHRUSCINSKI, Dariusz: Nicolaus Copernicus University, Torun, Poland |
CIRILO-LOMBARDO, Diego: Bogoliubov Laboratory of Theoretical Physics (JINR-Dubna), Russia |
CLEMENTE-GALLARDO, Jesus: BIFI-Universidad de Zaragoza, Spain |
DE LUCAS, Javier: Universidad de Zaragoza, Spain |
FALCETO, Fernando: Universidad de Zaragoza, Spain |
GINOCCHIO, Joseph: Los Alamos National Laboratory, USA |
GORINI, Vittorio: Universitá' dell' Insubria, Como, Italy |
INDURAIN, Javier: Universidad de Zaragoza, Spain |
KLAUDER, John: University of Florida, USA |
KOSSAKOWSKI, Andrzej: Nicolaus Copernicus University, Torun, Poland |
MARMO, Giuseppe: Università di Napoli Federico II, Italy |
MORANDI, Giuseppe: Universitá di Bologna-Italy |
MUKUNDA, Narasimhaiengar: Indian Institute of Science, Bangalore, India |
MUÑOZ-CASTAÑEDA, Jose M.: University of Zaragoza, Spain |
NAIR, RANJIT: Centre for Philosophy & Foundations of Science, New Delhi, India |
NILSSON, Jan S: University of Gothenburg, Sweden |
OKUBO, Susumu: University of Rochester, USA |
PASCAZIO, Saverio: Universitá di Bari, Italy |
RIVERA HERNÁNDEZ, Rayito: Université Pierre et Marie Curie, Paris, France |
RODRIGUEZ, Cesar: University of Texas - Austin, USA |
SCOLARICI, Giuseppe: Universitá del Salento, Lecce, Italy |
SEGUI, Antonio: Universidad de Zaragoza, Spain |
SHAPIRO, Ilya: Universidade Federal de Juiz de Fora, Brasil |
SIMONI, Alberto: Università di Napoli Federico II, Italy |
SOLOMON, Allan: Open University/ University of Paris VI, UK/France |
SUDARSHAN, Ashok: |
SUDARSHAN, George: University of Texas at Austin, USA |
TULCZYJEW, Wlodzimierz: Universitá di Camerino, Italy |
UCHIYAMA, Chikako: University of Yamanashi, Japan |
VENTRIGLIA, Franco: Università di Napoli Federico II, Italy |
VILASI, Gaetano: Universitá di Salerno, Italy |
ZACCARIA, Francesco: Universitá di Napoli Federico II, Italy |
Visions: The coming revolutions in particle physics
Chris Quigg
2002-04-11
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.
Theoretical Studies in Elementary Particle Physics
Collins, John C.; Roiban, Radu S
2013-04-01
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.
Is Particle Physics Ready for the LHC
Lykken, Joseph
2009-09-01
The advent of the Large Hadron Collider in 2007 entails daunting challenges to particle physicists. The first set of challenges will arise from trying to separate new physics from old. The second set of challenges will come in trying to interpret the new discoveries. I will describe a few of the scariest examples.
Physics of Quantum Structures in Photovoltaic Devices
NASA Technical Reports Server (NTRS)
Raffaelle, Ryne P.; Andersen, John D.
2005-01-01
There has been considerable activity recently regarding the possibilities of using various nanostructures and nanomaterials to improve photovoltaic conversion of solar energy. Recent theoretical results indicate that dramatic improvements in device efficiency may be attainable through the use of three-dimensional arrays of zero-dimensional conductors (i.e., quantum dots) in an ordinary p-i-n solar cell structure. Quantum dots and other nanostructured materials may also prove to have some benefits in terms of temperature coefficients and radiation degradation associated with space solar cells. Two-dimensional semiconductor superlattices have already demonstrated some advantages in this regard. It has also recently been demonstrated that semiconducting quantum dots can also be used to improve conversion efficiencies in polymeric thin film solar cells. Improvement in thin film cells utilizing conjugated polymers has also be achieved through the use of one-dimensional quantum structures such as carbon nanotubes. It is believed that carbon nanotubes may contribute to both the disassociation as well as the carrier transport in the conjugated polymers used in certain thin film photovoltaic cells. In this paper we will review the underlying physics governing some of the new photovoltaic nanostructures being pursued, as well as the the current methods being employed to produce III-V, II-VI, and even chalcopyrite-based nanomaterials and nanostructures for solar cells.
Current experiments in elementary particle physics
Wohl, C.G.; Armstrong, F.E., Oyanagi, Y.; Dodder, D.C.; Ryabov, Yu.G.; Frosch, R.; Olin, A.; Lehar, F.; Moskalev, A.N.; Barkov, B.P.
1987-03-01
This report contains summaries of 720 recent and current experiments in elementary particle physics (experiments that finished taking data before 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. Instructions are given for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries. Properties of the fixed-target beams at most of the laboratories are summarized.
Medical physics aspects of particle therapy.
Jkel, Oliver
2009-11-01
Charged particle beams offer an improved dose conformation to the target volume when compared with photon radiotherapy, with better sparing of normal tissue structures close to the target. In addition, beams of heavier ions exhibit a strong increase of the linear energy transfer in the Bragg peak when compared with the entrance region. These physical and biological properties make ion beams more favourable for radiation therapy of cancer than photon beams. As a consequence, particle therapy with protons and heavy ions has gained increasing interest worldwide. This contribution summarises the physical and biological principles of charged particle therapy with ion beams and highlights some of the developments in the field of beam delivery, the principles of treatment planning and the determination of absorbed dose in ion beams. The clinical experience gathered so far with carbon ion therapy is briefly reviewed. PMID:19828718
Current Experiments in Particle Physics (September 1996)
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
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.
Hausdorff dimension of a particle path in a quantum manifold
Nicolini, Piero; Niedner, Benjamin
2011-01-15
After recalling the concept of the Hausdorff dimension, we study the fractal properties of a quantum particle path. As a novelty we consider the possibility for the space where the particle propagates to be endowed with a quantum-gravity-induced minimal length. We show that the Hausdorff dimension accounts for both the quantum mechanics uncertainty and manifold fluctuations. In addition the presence of a minimal length breaks the self-similarity property of the erratic path of the quantum particle. Finally we establish a universal property of the Hausdorff dimension as well as the spectral dimension: They both depend on the amount of resolution loss which affects both the path and the manifold when quantum gravity fluctuations occur.
Physical realization of the Glauber quantum oscillator.
Gentilini, Silvia; Braidotti, Maria Chiara; Marcucci, Giulia; DelRe, Eugenio; Conti, Claudio
2015-01-01
More than thirty years ago Glauber suggested that the link between the reversible microscopic and the irreversible macroscopic world can be formulated in physical terms through an inverted harmonic oscillator describing quantum amplifiers. Further theoretical studies have shown that the paradigm for irreversibility is indeed the reversed harmonic oscillator. As outlined by Glauber, providing experimental evidence of these idealized physical systems could open the way to a variety of fundamental studies, for example to simulate irreversible quantum dynamics and explain the arrow of time. However, supporting experimental evidence of reversed quantized oscillators is lacking. We report the direct observation of exploding n = 0 and n = 2 discrete states and Γ0 and Γ2 quantized decay rates of a reversed harmonic oscillator generated by an optical photothermal nonlinearity. Our results give experimental validation to the main prediction of irreversible quantum mechanics, that is, the existence of states with quantized decay rates. Our results also provide a novel perspective to optical shock-waves, potentially useful for applications as lasers, optical amplifiers, white-light and X-ray generation. PMID:26522653
Physical realization of the Glauber quantum oscillator
Gentilini, Silvia; Braidotti, Maria Chiara; Marcucci, Giulia; DelRe, Eugenio; Conti, Claudio
2015-01-01
More than thirty years ago Glauber suggested that the link between the reversible microscopic and the irreversible macroscopic world can be formulated in physical terms through an inverted harmonic oscillator describing quantum amplifiers. Further theoretical studies have shown that the paradigm for irreversibility is indeed the reversed harmonic oscillator. As outlined by Glauber, providing experimental evidence of these idealized physical systems could open the way to a variety of fundamental studies, for example to simulate irreversible quantum dynamics and explain the arrow of time. However, supporting experimental evidence of reversed quantized oscillators is lacking. We report the direct observation of exploding n = 0 and n = 2 discrete states and Γ0 and Γ2 quantized decay rates of a reversed harmonic oscillator generated by an optical photothermal nonlinearity. Our results give experimental validation to the main prediction of irreversible quantum mechanics, that is, the existence of states with quantized decay rates. Our results also provide a novel perspective to optical shock-waves, potentially useful for applications as lasers, optical amplifiers, white-light and X-ray generation. PMID:26522653
Physical realization of the Glauber quantum oscillator
NASA Astrophysics Data System (ADS)
Gentilini, Silvia; Braidotti, Maria Chiara; Marcucci, Giulia; Delre, Eugenio; Conti, Claudio
2015-11-01
More than thirty years ago Glauber suggested that the link between the reversible microscopic and the irreversible macroscopic world can be formulated in physical terms through an inverted harmonic oscillator describing quantum amplifiers. Further theoretical studies have shown that the paradigm for irreversibility is indeed the reversed harmonic oscillator. As outlined by Glauber, providing experimental evidence of these idealized physical systems could open the way to a variety of fundamental studies, for example to simulate irreversible quantum dynamics and explain the arrow of time. However, supporting experimental evidence of reversed quantized oscillators is lacking. We report the direct observation of exploding n = 0 and n = 2 discrete states and Γ0 and Γ2 quantized decay rates of a reversed harmonic oscillator generated by an optical photothermal nonlinearity. Our results give experimental validation to the main prediction of irreversible quantum mechanics, that is, the existence of states with quantized decay rates. Our results also provide a novel perspective to optical shock-waves, potentially useful for applications as lasers, optical amplifiers, white-light and X-ray generation.
Teaching Quantum Physics in Upper Secondary School in France:
ERIC Educational Resources Information Center
Lautesse, Philippe; Vila Valls, Adrien; Ferlin, Fabrice; Héraud, Jean-Loup; Chabot, Hugues
2015-01-01
One of the main problems in trying to understand quantum physics is the nature of the referent of quantum theory. This point is addressed in the official French curriculum in upper secondary school. Starting in 2012, after about 20 years of absence, quantum physics has returned to the national program. On the basis of the historical construction…
Teaching Quantum Physics in Upper Secondary School in France:
ERIC Educational Resources Information Center
Lautesse, Philippe; Vila Valls, Adrien; Ferlin, Fabrice; Hraud, Jean-Loup; Chabot, Hugues
2015-01-01
One of the main problems in trying to understand quantum physics is the nature of the referent of quantum theory. This point is addressed in the official French curriculum in upper secondary school. Starting in 2012, after about 20years of absence, quantum physics has returned to the national program. On the basis of the historical construction
Physics of the Blues: Music, Fourier and Wave - Particle Duality
Gibson, J. Murray
2003-10-15
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.
Summation of power series in particle physics
NASA Astrophysics Data System (ADS)
Fischer, Jan
1999-04-01
The large-order behaviour of power series used in quantum theory (perturbation series and the operator-product expansion) is discussed and relevant summation methods are reviewed. It is emphasised that, in most physically interesting situations, the mere knowledge of the expansion coefficients is not sufficient for a unique determination of the function expanded, and the necessity of some additional, extra-perturbative, input is pointed out. Several possible nonperturbative inputs are suggested. Applications to various problems of quantum chromodynamics are considered. This lecture was presented on the special Memorial Day dedicated to Professor Ryszard R˛czka at this Workshop. The last section is devoted to my personal recollections of this remarkable personality.
Particles, Waves, and the Interpretation of Quantum Mechanics
ERIC Educational Resources Information Center
Christoudouleas, N. D.
1975-01-01
Presents an explanation, without mathematical equations, of the basic principles of quantum mechanics. Includes wave-particle duality, the probability character of the wavefunction, and the uncertainty relations. (MLH)
Moore's law: new playground for quantum physics
NASA Astrophysics Data System (ADS)
van Rossum, M.; Schoenmaker, W.; Magnus, W.; de Meyer, K.; Croitoru, M. D.; Gladilin, V. N.; Fomin, V. M.; Devreese, J. T.
2003-05-01
CMOS technology has been proven as one of the most important achievements in modern engineering history. In less than 30 years, it has become the primary engine driving the world economy. Device scaling makes this possible. For decades, progress in device scaling has followed an exponential curve: this has come to be known as Moore's law. Downscaling such devices like MOSFETs to their limiting sizes is a key challenge of the semiconductor industry now. Therefore device simulation requires new theory and modeling techniques, what helps to improve the understanding of device physics and design, for structures at the sub-100 nm scale, and complements experimental work in addressing this challenge. We present a new approach, which allows us to make predictions about performance of future MOSFETs. The quantum-mechanical features of the electron transport are extracted from the numerical solution of the quantum Liouville equation in the Wigner function representation.
Quantum measurement: a bridge to classical physics
NASA Astrophysics Data System (ADS)
Emch, Gerard G.
2003-08-01
In light of the lessons learned in the last 35 years from the quantum statistical mechanics description of phase transitions, I argue that the dichotomy in the evolution of quantum systems proposed by von Neumann, and pursued by Wigner in spite of the Einstein--Bohr criticisms on the attendent lack of resolution in terms of classical reality, fails to take into account the middle term suggested by the existence of superselection rules, Wigner's own discovery (with Wightmann and Wick). I claim that the part of the measurement problem concerned with the stable transfer of microscopic information to macroscopic physics can be treated entirely within the framework of a deterministic, conservative evolution of the joint system, i.e. without requiring the type of evolution von Neumann proposed besides that governed by the Schroedinger equation. I sustain this claim with the use of an exactly solvable model akin to the x-y model of statistical mechanics and involving its thermodynamical limit.
Energetic particle physics issues for ITER
Cheng, C.Z.; Budny, R.; Fu, G.Y.
1996-12-31
This paper summarizes our present understanding of the following energetic/alpha particle physics issues for the 21 MA, 20 TF coil ITER Interim Design configuration and operational scenarios: (a) toroidal field ripple effects on alpha particle confinement, (b) energetic particle interaction with low frequency MHD modes, (c) energetic particle excitation of toroidal Alfven eigenmodes, and (d) energetic particle transport due to MHD modes. TF ripple effects on alpha loss in ITER under a number of different operating conditions are found to be small with a maximum loss of 1%. With careful plasma control in ITER reversed-shear operation, TF ripple induced alpha loss can be reduced to below the nominal ITER design limit of 5%. Fishbone modes are expected to be unstable for {beta}{sub {alpha}} > 1%, and sawtooth stabilization is lost if the ideal kink growth rate exceeds 10% of the deeply trapped alpha precessional drift frequency evaluated at the q = 1 surface. However, it is expected that the fishbone modes will lead only to a local flattening of the alpha profile due to small banana size. MHD modes observed during slow decrease of stored energy after fast partial electron temperature collapse in JT-60U reversed-shear experiments may be resonant type instabilities; they may have implications on the energetic particle confinement in ITER reversed-shear operation. From the results of various TAE stability code calculations, ITER equilibria appear to lie close to TAE linear stability thresholds. However, the prognosis depends strongly on q profile and profiles of alpha and other high energy particles species. If TAE modes are unstable in ITER, the stochastic diffusion is the main loss mechanism, which scales with ({delta}B{sub r}/B){sup 2}, because of the relatively small alpha particle banana orbit size. For isolated TAE modes the particle loss is very small, and TAE modes saturate via the resonant wave-particle trapping process at very small amplitude.
Size and temperature dependent plasmons of quantum particles
NASA Astrophysics Data System (ADS)
Xiao, Mufei; Rakov, Nikifor
2015-08-01
This work reports on the influences of temperature changes on plasmons of metallic particles that are so small that electric carriers in the conduction band are forced to be at discrete sub-bands due to quantum confinement. In the framework of the electron-in-a-box model and with an every-electron-count computational scheme, the spatial electric distribution inside the particle is calculated. In the calculations, the intra-subband fluctuations are taken into account. The numerical results have shown that the small-particle plasmon frequency shifts with the temperature. The findings suggest that it would be possible to control the plasmons of quantum particles externally.
New developments in photodetection for particle physics and nuclear physics
NASA Astrophysics Data System (ADS)
Elias, J. E.
2000-03-01
Photodetectors are widely used in particle and nuclear physics research. Since the beginning of the modern era of photoelectric transducers in the late 1930s, many types of devices have been developed and exploited for physics research. New performance requirements arising in physics experiments have often provided very interesting technological drivers for industry. New ideas for photo-detection are rapidly adapted by the physics community to enable more powerful experimental capabilities. This report gives a sampling of new developments in photodetection for physics research in the period since the first conference in this series, Beaune 96. Representative examples of advances in vacuum devices, solid-state devices and gaseous photodetectors are described including, where appropriate, areas where technological improvements are needed or expected.
NASA Astrophysics Data System (ADS)
Baily, Charles Raymond
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.
Quantum Dots: An Experiment for Physical or Materials Chemistry
ERIC Educational Resources Information Center
Winkler, L. D.; Arceo, J. F.; Hughes, W. C.; DeGraff, B. A.; Augustine, B. H.
2005-01-01
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.
On the physical realizability of quantum stochastic walks
NASA Astrophysics Data System (ADS)
Taketani, Bruno; Govia, Luke; Schuhmacher, Peter; Wilhelm, Frank
Quantum walks are a promising framework that can be used to both understand and implement quantum information processing tasks. The recently developed quantum stochastic walk combines the concepts of a quantum walk and a classical random walk through open system evolution of a quantum system, and have been shown to have applications in as far reaching fields as artificial intelligence. However, nature puts significant constraints on the kind of open system evolutions that can be realized in a physical experiment. In this work, we discuss the restrictions on the allowed open system evolution, and the physical assumptions underpinning them. We then introduce a way to circumvent some of these restrictions, and simulate a more general quantum stochastic walk on a quantum computer, using a technique we call quantum trajectories on a quantum computer. We finally describe a circuit QED approach to implement discrete time quantum stochastic walks.
Measurement theory in local quantum physics
NASA Astrophysics Data System (ADS)
Okamura, Kazuya; Ozawa, Masanao
2016-01-01
In this paper, we aim to establish foundations of measurement theory in local quantum physics. For this purpose, we discuss a representation theory of completely positive (CP) instruments on arbitrary von Neumann algebras. We introduce a condition called the normal extension property (NEP) and establish a one-to-one correspondence between CP instruments with the NEP and statistical equivalence classes of measuring processes. We show that every CP instrument on an atomic von Neumann algebra has the NEP, extending the well-known result for type I factors. Moreover, we show that every CP instrument on an injective von Neumann algebra is approximated by CP instruments with the NEP. The concept of posterior states is also discussed to show that the NEP is equivalent to the existence of a strongly measurable family of posterior states for every normal state. Two examples of CP instruments without the NEP are obtained from this result. It is thus concluded that in local quantum physics not every CP instrument represents a measuring process, but in most of physically relevant cases every CP instrument can be realized by a measuring process within arbitrary error limits, as every approximately finite dimensional von Neumann algebra on a separable Hilbert space is injective. To conclude the paper, the concept of local measurement in algebraic quantum field theory is examined in our framework. In the setting of the Doplicher-Haag-Roberts and Doplicher-Roberts theory describing local excitations, we show that an instrument on a local algebra can be extended to a local instrument on the global algebra if and only if it is a CP instrument with the NEP, provided that the split property holds for the net of local algebras.
Synthesis and optical properties of quantum-size metal sulfide particles in aqueous solution
Nedeljkovic, J.M.; Patel, R.C.; Kaufman, P.; Joyce-Pruden, C.; O'Leary, N. )
1993-04-01
During the past decade, small-particle' research has become quite popular in various fields of chemistry and physics. The recognition of quantum-size effects in very small colloidal particles has led to renewed interest in this area. Small particles' are clusters of atoms or molecules ranging in size from 1 nm to almost 10 nm or having agglomeration numbers from 10 up to a few hundred. In other words, small particles fall in size between single atoms or molecules and bulk materials. The agglomeration number specifies the number of individual atoms or molecules in a given cluster. The research in this area is interdisciplinary, and it links colloidal science and molecular chemistry. The symbiosis of these two areas of research has revealed some intriguing characteristics of small particles. This experiment illustrates the following: simple colloidal techniques for the preparation of two different types of quantum-size metal sulfide particles; the blue shift of the measured optical absorption spectra when the particle size is decreased in the quantum-size regime; and use of a simple quantum mechanical model to calculate the particle size from the absorption onset measured for CdS.
Cyclic Polyynes as Examples of the Quantum Mechanical Particle on a Ring
ERIC Educational Resources Information Center
Anderson, Bruce D.
2012-01-01
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
Cyclic Polyynes as Examples of the Quantum Mechanical Particle on a Ring
ERIC Educational Resources Information Center
Anderson, Bruce D.
2012-01-01
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…
Recasting particle physics by entangling physics, history and philosophy
NASA Astrophysics Data System (ADS)
Bertozzi, Eugenio; Levrini, Olivia
2016-05-01
-1The paper presents the design process we followed to recast particle physics so as to make it conceptually relevant for secondary school students. In this design process, the concept of symmetry was assumed as core-idea because of its structural and foundational role in particle physics, its crosscutting character and its epistemological and philosophical value. The first draft of the materials was tested in a pilot-study which involved 19 students of a regular class (grade 13) of an Italian school. The data analysis showed that the students were in their "regime of competence" for grasping subtle nuances of the materials and for providing important hints for revising them. In particular, students' reactions brought into light the need of clarifying the "foundational" character that symmetry attained in twentieth-century physics. The delicate step of re-thinking the materials required the researchers to articulate the complex relationship between researches on physics teaching, history and philosophy of physics. This analytic phase resulted in a version of the materials which implies the students to be guided to grasp the meaning of symmetry as normative principle in twentieth-century physics, throughout the exploration of the different meanings assumed by symmetry over time. The whole process led also to the production of an essential, on-line version, of the materials targeted to a wider audience.
Advanced analysis methods in particle physics
Bhat, Pushpalatha C.; /Fermilab
2010-10-01
Each generation of high energy physics experiments is grander in scale than the previous - more powerful, more complex and more demanding in terms of data handling and analysis. The spectacular performance of the Tevatron and the beginning of operations of the Large Hadron Collider, have placed us at the threshold of a new era in particle physics. The discovery of the Higgs boson or another agent of electroweak symmetry breaking and evidence of new physics may be just around the corner. The greatest challenge in these pursuits is to extract the extremely rare signals, if any, from huge backgrounds arising from known physics processes. The use of advanced analysis techniques is crucial in achieving this goal. In this review, I discuss the concepts of optimal analysis, some important advanced analysis methods and a few examples. The judicious use of these advanced methods should enable new discoveries and produce results with better precision, robustness and clarity.
The Qubit as Key to Quantum Physics Part II: Physical Realizations and Applications
ERIC Educational Resources Information Center
Dür, Wolfgang; Heusler, Stefan
2016-01-01
Using the simplest possible quantum system--the qubit--the fundamental concepts of quantum physics can be introduced. This highlights the common features of many different physical systems, and provides a unifying framework when teaching quantum physics at the high school or introductory level. In a previous "TPT" article and in a…
The Qubit as Key to Quantum Physics Part II: Physical Realizations and Applications
ERIC Educational Resources Information Center
Dr, Wolfgang; Heusler, Stefan
2016-01-01
Using the simplest possible quantum system--the qubit--the fundamental concepts of quantum physics can be introduced. This highlights the common features of many different physical systems, and provides a unifying framework when teaching quantum physics at the high school or introductory level. In a previous "TPT" article and in a
BOOK REVIEW: Quantum Physics in One Dimension
NASA Astrophysics Data System (ADS)
Logan, David
2004-05-01
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 discussed. According to taste and interest, these chapters can be read in essentially any order. Spin systems are considered in chapter 6, beginning with spin chains---Jordan--Wigner, the bosonization solution---before moving to frustration, the spin-Peierls transition, and spin ladders; and including experimental examples of both spin chain and ladder materials. Chapters 7 and 8 deal with interacting lattice fermions, the former with single chain problems, notably the Hubbard, t-J and related models; and the latter with coupled fermionic chains, from finite to infinite, including a fulsome discussion of Bechgaard salts (organic conductors) as exemplars of Luttinger liquid behaviour. The effect of disorder in fermionic systems is taken up in chapter 9, and here the reader may react: interacting systems are tough enough, why make life harder? But disorder is always present to some degree in real systems---quantum wires, for example, discussed briefly in the chapter---and its effects particularly acute in one dimension. It simply cannot be avoided, even if the problem of interacting, disordered one-dimensional systems is still a long way off being solved. The penultimate chapter deals with the topical issues of boundaries, isolated impurities and constrictions, with a primary focus on mesoscopic examples of Luttinger liquids, notably carbon nanotubes and edge states in the quantum Hall effect. Finally `significant other' examples of Luttinger liquids, namely interacting one-dimensional bosons, are considered in chapter 11; which concludes with a discussion of bosonization techniques in the context of quantum impurities in Fermi liquids---the x-ray, Kondo and multichannel Kondo problems. The quality of the product attests to the fact that writing this impressive tome was a labour of love for the author. Anyone with a serious interest in getting to grips with one-dimensional quantum systems simply needs the book on their shelves---and will have great fun reading it too.
Current experiments in elementary particle physics
Wohl, C.G.; Armstrong, F.E.; Trippe, T.G.; Yost, G.P. ); Oyanagi, Y. ); Dodder, D.C. ); Ryabov, Yu.G.; Slabospitsky, S.R. . Inst. Fiziki Vysokikh Ehnergij); Frosch, R. (Swiss Inst. for Nuclear Research, Villigen (Switzerla
1989-09-01
This report contains summaries of 736 current and recent experiments in elementary particle physics (experiments that finished taking data before 1982 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Tokyo Institute of Nuclear Studies, Moscow Institute of Theoretical and Experimental Physics, Joint Institute for Nuclear Research (Dubna), KEK, LAMPF, Novosibirsk, PSI/SIN, Saclay, Serpukhov, SLAC, and TRIUMF, and also several underground experiments. Also given are instructions for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries. Properties of the fixed-target beams at most of the laboratories are summarized.
Current experiments in elementary particle physics. Revised
Galic, H.; Wohl, C.G.; Armstrong, B.; Dodder, D.C.; Klyukhin, V.I.; Ryabov, Yu.G.; Illarionova, N.S.; Lehar, F.; Oyanagi, Y.; Olin, A.; Frosch, R.
1992-06-01
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.
Particle physics: recent successes and future prospects
Wojcicki, S.
1984-12-01
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.
FINAL REPORT: GEOMETRY AND ELEMENTARY PARTICLE PHYSICS
Singer, Isadore M.
2008-03-04
The effect on mathematics of collaborations between high-energy theoretical physics and modern mathematics has been remarkable. Mirror symmetry has revolutionized enumerative geometry, and Seiberg-Witten invariants have greatly simplified the study of four manifolds. And because of their application to string theory, physicists now need to know cohomology theory, characteristic classes, index theory, K-theory, algebraic geometry, differential geometry, and non-commutative geometry. Much more is coming. We are experiencing a deeper contact between the two sciences, which will stimulate new mathematics essential to the physicists’ quest for the unification of quantum mechanics and relativity. Our grant, supported by the Department of Energy for twelve years, has been instrumental in promoting an effective interaction between geometry and string theory, by supporting the Mathematical Physics seminar, postdoc research, collaborations, graduate students and several research papers.
Semiconductor detectors in nuclear and particle physics
Rehak, P.; Gatti, E.
1992-12-31
Semiconductor detectors for elementary particle physics and nuclear physics in the energy range above 1 GeV are briefly reviewed. In these two fields semiconductor detectors are used mainly for the precise position sensing. In a typical experiment, the position of a fast charged particle crossing a relatively thin semiconductor detector is measured. The position resolution achievable by semiconductor detectors is compared with the resolution achievable by gas filled position sensing detectors. Semiconductor detectors are divided into two groups: Classical semiconductor diode detectors and semiconductor memory detectors. Principles of the signal formation and the signal read-out for both groups of detectors are described. New developments of silicon detectors of both groups are reported.
Current experiments in elementary particle physics. Revision
Galic, H.; Armstrong, F.E.; von Przewoski, B.
1994-08-01
This report contains summaries of 568 current and recent experiments in elementary particle physics. Experiments that finished taking data before 1988 are excluded. Included are experiments at BEPC (Beijing), BNL, CEBAF, CERN, CESR, DESY, FNAL, INS (Tokyo), ITEP (Moscow), IUCF (Bloomington), KEK, LAMPF, Novosibirsk, PNPI (St. Petersburg), PSI, Saclay, Serpukhov, SLAC, 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.
Theoretical studies in elementary particle physics
NASA Astrophysics Data System (ADS)
Collins, J. C.
This report briefly discusses the elementary particle physics research being done at Illinois Institute of Technology. Some of the work in progress is: understanding the foundations of perturbative QCD in its applications to hadron-hadron scattering; studies of the QCD predictions for the angular distribution of the muons produced in the Drell-Yan process; the small-x regime and cosmic ray signals from Cygnus X-3.
Wave theories of non-laminar charged particle beams: from quantum to thermal regime
NASA Astrophysics Data System (ADS)
Fedele, Renato; Tanjia, Fatema; Jovanović, Dusan; de Nicola, Sergio; Ronsivalle, Concetta; Ronsivalle
2014-04-01
The standard classical description of non-laminar charged particle beams in paraxial approximation is extended to the context of two wave theories. The first theory that we discuss (Fedele R. and Shukla, P. K. 1992 Phys. Rev. A 45, 4045. Tanjia, F. et al. 2011 Proceedings of the 38th EPS Conference on Plasma Physics, Vol. 35G. Strasbourg, France: European Physical Society) is based on the Thermal Wave Model (TWM) (Fedele, R. and Miele, G. 1991 Nuovo Cim. D 13, 1527.) that interprets the paraxial thermal spreading of beam particles as the analog of quantum diffraction. The other theory is based on a recently developed model (Fedele, R. et al. 2012a Phys. Plasmas 19, 102106; Fedele, R. et al. 2012b AIP Conf. Proc. 1421, 212), hereafter called Quantum Wave Model (QWM), that takes into account the individual quantum nature of single beam particle (uncertainty principle and spin) and provides collective description of beam transport in the presence of quantum paraxial diffraction. Both in quantum and quantum-like regimes, the beam transport is governed by a 2D non-local Schrödinger equation, with self-interaction coming from the nonlinear charge- and current-densities. An envelope equation of the Ermakov-Pinney type, which includes collective effects, is derived for both TWM and QWM regimes. In TWM, such description recovers the well-known Sacherer's equation (Sacherer, F. J. 1971 IEEE Trans. Nucl. Sci. NS-18, 1105). Conversely, in the quantum regime and in Hartree's mean field approximation, one recovers the evolution equation for a single-particle spot size, i.e. for a single quantum ray spot in the transverse plane (Compton regime). We demonstrate that such quantum evolution equation contains the same information as the evolution equation for the beam spot size that describes the beam as a whole. This is done heuristically by defining the lowest QWM state accessible by a system of non-overlapping fermions. The latter are associated with temperature values that are sufficiently low to make the single-particle quantum effects visible on the beam scale, but sufficiently high to make the overlapping of the single-particle wave functions negligible. This lowest QWM state constitutes the border between the fundamental single-particle Compton regime and the collective quantum and thermal regimes at larger (nano- to micro-) scales. Comparing it with the beam parameters in the existing accelerators, we find that it is feasible to achieve nano-sized beams in advanced compact machines.
Designing Learning Environments to Teach Interactive Quantum Physics
ERIC Educational Resources Information Center
Puente, Sonia M. Gomez; Swagten, Henk J. M.
2012-01-01
This study aims at describing and analysing systematically an interactive learning environment designed to teach Quantum Physics, a second-year physics course. The instructional design of Quantum Physics is a combination of interactive lectures (using audience response systems), tutorials and self-study in unit blocks, carried out with small…
Refined Characterization of Student Perspectives on Quantum Physics
ERIC Educational Resources Information Center
Baily, Charles; Finkelstein, Noah D.
2010-01-01
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…
Designing Learning Environments to Teach Interactive Quantum Physics
ERIC Educational Resources Information Center
Puente, Sonia M. Gomez; Swagten, Henk J. M.
2012-01-01
This study aims at describing and analysing systematically an interactive learning environment designed to teach Quantum Physics, a second-year physics course. The instructional design of Quantum Physics is a combination of interactive lectures (using audience response systems), tutorials and self-study in unit blocks, carried out with small
Refined Characterization of Student Perspectives on Quantum Physics
ERIC Educational Resources Information Center
Baily, Charles; Finkelstein, Noah D.
2010-01-01
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
Charting the Course for Elementary Particle Physics
Richter, Burton
2007-02-20
''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.
Charting the Course for Elementary Particle Physics
DOE R&D Accomplishments Database
Richter, B.
2007-02-16
"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.
Quantum Humor: The Playful Side of Physics at Bohr's Institute for Theoretical Physics
NASA Astrophysics Data System (ADS)
Halpern, Paul
2012-09-01
From the 1930s to the 1950s, a period of pivotal developments in quantum, nuclear, and particle physics, physicists at Niels Bohr's Institute for Theoretical Physics in Copenhagen took time off from their research to write humorous articles, letters, and other works. Best known is the Blegdamsvej Faust, performed in April 1932 at the close of one of the Institute's annual conferences. I also focus on the Journal of Jocular Physics, a humorous tribute to Bohr published on the occasions of his 50th, 60th, and 70th birthdays in 1935, 1945, and 1955. Contributors included Léon Rosenfeld, Victor Weisskopf, George Gamow, Oskar Klein, and Hendrik Casimir. I examine their contributions along with letters and other writings to show that they offer a window into some issues in physics at the time, such as the interpretation of complementarity and the nature of the neutrino, as well as the politics of the period.
ERIC Educational Resources Information Center
Baily, Charles; Finkelstein, Noah D.
2015-01-01
Most introductory quantum physics instructors would agree that transitioning students from classical to quantum thinking is an important learning goal, but may disagree on whether or how this can be accomplished. Although (and perhaps because) physicists have long debated the physical interpretation of quantum theory, many instructors choose to…
Research program in particle physics. Progress report, January 1, 1993--December 1993
Sudarshan, E.C.G.; Dicus, D.A.; Ritchie, J.L.; Lang, K.
1993-05-01
This report is the progress report for DOE funded support of particle physics work at the University of Texas, Austin. Support was divided between theoretical and experimental programs, and each is reviewed separately in the report. Theoretical effort was divided between three general areas: quantum gravity and mathematical physics; phenomenology; and quantum mechanics and quantum field theory. Experimental effort was primarily directed toward AGS experiments at Brookhaven, to look for rare kaon decays. AGS experiments 791 and 871 are described, along with BNL experiment 888.
Current experiments in particle physics - particle data group
Galic, H.; Lehar, F.; Kettle, P.R.
1996-09-01
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.
Quantum interface to charged particles in a vacuum
NASA Astrophysics Data System (ADS)
Okamoto, Hiroshi
2015-11-01
A superconducting qubit device suitable for interacting with a flying electron has recently been proposed [Okamoto and Nagatani, Appl. Phys. Lett. 104, 062604 (2014), 10.1063/1.4865244]. Either a clockwise or counterclockwise directed loop of half magnetic flux quantum encodes a qubit, which naturally interacts with any single charged particle with arbitrary kinetic energy. Here, the device's properties, sources of errors, and possible applications are studied in detail. In particular, applications include detection of a charged particle essentially without applying a classical force to it. Furthermore, quantum states can be transferred between an array of the proposed devices and the charged particle.
Nuclear and particle physics in the early universe
NASA Technical Reports Server (NTRS)
Schramm, D. N.
1981-01-01
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.
The Coming Revolutions in Particle Physics
Quigg, Chris
2009-09-01
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. We look forward to 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. We suspect that the detection of proton decay is only a few orders of magnitude away in sensitivity. Astronomical observations should help to tell us what kinds of matter and energy make up the universe. 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 electron-positron 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.
Can multi-particle systems be too entangled to be useful for quantum computation?
NASA Astrophysics Data System (ADS)
Eisert, Jens
2009-03-01
In the context of ``quantum information meets many-particle physics'', we pose the question of the role of entanglement in the quantum computational power of many-particle quantum systems (1). It is often argued that entanglement is at the root of the speedup for quantum compared to classical computation, and that one needs sufficient entanglement for this speedup to be manifest. In measurement-based quantum computing, the need for a highly entangled initial state is particularly obvious. In this work we show that, remarkably, quantum states can be too entangled - in the sense of having a too large geometric entanglement - to be useful for the purpose of computation. What is more, we can prove that this phenomenon occurs for the dramatic majority of all states: the fraction of pure states on n qubits not subject to the problem is smaller than e^-n^2. Our results show that computational universality is actually a rare property in quantum states. For the proof we make use of a link between the ``quantum probabilistic method'' and ideas on quantum many-body systems. This work stresses a new aspect of the question concerning the role entanglement plays for quantum computational speed-ups. We will also investigate a new classification of primitives from projected entangled pair states (PEPS) that can be used in order to systematically construct new models for measurement-based computation (2,3). In an outlook, I will - if time allows - mention other recent group activities related to quantum information and many-particle physics, including dynamical area laws and relaxation statements (4,5). [4pt] (1) ``Most quantum states are too entangled to be useful as computational resources'', Phys. Rev. Lett., in press (2009)[0pt] (2) ``Quantum computational webs'', arXiv:0810.2542[0pt] (3) ``Novel schemes for measurement-based quantum computation'', Phys. Rev. Lett. 98, 220503 (2007)[0pt] (4) ``Exact relaxation in a class of nonequilibrium quantum lattice systems'', Phys. Rev. Lett. 100, 030602 (2008)0[pt] (5) ``Area laws for the entanglement entropy'', Rev. Mod. Phys., in press (2009).
Quantum graphs with two-particle contact interactions
NASA Astrophysics Data System (ADS)
Bolte, Jens; Kerner, Joachim
2013-02-01
We construct models of many-particle quantum graphs with singular two-particle contact interactions, which can be either hardcore- or δ-interactions. Self-adjoint realizations of the two-particle Laplacian including such interactions are obtained via their associated quadratic forms. We prove discreteness of spectra as well as Weyl laws for the asymptotic eigenvalue counts. These constructions are first performed for two distinguishable particles and then for two identical bosons. Furthermore, we extend the models to N bosons with two-particle interactions, thus implementing the Lieb-Liniger model on a graph.
Tests of the particle physics-physical cosmology interface
Schramm, D.N. Fermi National Accelerator Lab., Batavia, IL )
1993-01-01
Three interrelated interfaces of particle physics and physical cosmology are discussed: (1) inflation and other phase transitions; (2) Big Bang Nucleosynthesis (and also the quark-hadron transition); and (3) structure formation (including dark matter). Recent observations that affect each of these topics are discussed. Topic number 1 is shown to be consistent with the COBE observations but not proven and it may be having problems with some age-expansion data. Topic number 2 has now been well-tested and is an established pillar'' of the Big Bang. Topic number 3 is the prime arena of current physical cosmological activity. Experiments to resolve the current exciting, but still ambiguous, situation following the COBE results are discussed.
TOPICS IN THE PHYSICS OF PARTICLE ACCELERATORS
Sessler, A.M.
1984-07-01
High energy physics, perhaps more than any other branch of science, is driven by technology. It is not the development of theory, or consideration of what measurements to make, which are the driving elements in our science. Rather it is the development of new technology which is the pacing item. Thus it is the development of new techniques, new computers, and new materials which allows one to develop new detectors and new particle-handling devices. It is the latter, the accelerators, which are at the heart of the science. Without particle accelerators there would be, essentially, no high energy physics. In fact. the advances in high energy physics can be directly tied to the advances in particle accelerators. Looking terribly briefly, and restricting one's self to recent history, the Bevatron made possible the discovery of the anti-proton and many of the resonances, on the AGS was found the {mu}-neutrino, the J-particle and time reversal non-invariance, on Spear was found the {psi}-particle, and, within the last year the Z{sub 0} and W{sup {+-}} were seen on the CERN SPS p-{bar p} collider. Of course one could, and should, go on in much more detail with this survey, but I think there is no need. It is clear that as better acceleration techniques were developed more and more powerful machines were built which, as a result, allowed high energy physics to advance. What are these techniques? They are very sophisticated and ever-developing. The science is very extensive and many individuals devote their whole lives to accelerator physics. As high energy experimental physicists your professional lives will be dominated by the performance of 'the machine'; i.e. the accelerator. Primarily you will be frustrated by the fact that it doesn't perform better. Why not? In these lectures, six in all, you should receive some appreciation of accelerator physics. We cannot, nor do we attempt, to make you into accelerator physicists, but we do hope to give you some insight into the machines with which you will be involved in the years to come. Perhaps, we can even turn your frustration with the inadequacy of these machines into marvel at the performance of the accelerators. At the least, we hope to convince you that the accelerators are central, not peripheral, to our science and that the physics of such machines is both fascinating and sophisticated. The plan is the following: First I will give two lectures on basic accelerator physics; then you will hear two lectures on the state of the art, present limitations, the specific parameters of LEP, HERA, TEV2 and SLC, and some extrapolation to the next generation of machines such as the Large Hadron Collider (LHC), Superconducting Super Collider (SSC), and Large Linear Colliders; finally, I will give two lectures on new acceleration methods.
The Underlying Physics in Wetted Particle Collisions
NASA Astrophysics Data System (ADS)
Donahue, Carly; Hrenya, Christine; Davis, Robert
2008-11-01
Wetted granular particles are relevant in many industries including the pharmaceutical and chemical industries and has applications to granulation, filtration, coagulation, spray coating, drying and pneumatic transport. In our current focus, we investigate the dynamics of a three-body normal wetted particle collision. In order to conduct collisions we use an apparatus called a ``Stokes Cradle,'' similar to the Newton's Cradle (desktop toy) except that the target particles are covered with oil. Here, we are able to vary the oil thickness, oil viscosity, and material properties. With a three particle collision there are four possible outcomes: fully agglomerated (FA); Newton's Cradle (NC), the striker and the first target ball are agglomerated and the last target ball is separated; Reverse Newton's Cradle (RNC), the striker is separated and the two targets are agglomerated; and fully separated (FS). Varying the properties of the collisions, we have observed all four outcomes. We use elastohydrodynamics as a theoretical basis for modeling the system. We also have considered the glass transition of the oil as the pressure increases upon impact and the cavitation of the oil as the pressure drops below the vapor pressure upon rebound. A toy model has been developed where the collision is modeled as a series of two-body collisions. A qualitative agreement between the toy model and experiments gives insight into the underlying physics.
School on Particle Physics, Gravity and Cosmology
NASA Astrophysics Data System (ADS)
Brandenberger, Robert
These lectures present a brief review of inflationary cosmology, provide an overview of the theory of cosmological perturbations, and then focus on the conceptual problems of the current paradigm of early universe cosmology, thus motivating an exploration of the potential of string theory to provide a new paradigm. Specifically, the string gas cosmology model is introduced, and a resulting mechanism for structure formation which does not require a period of cosmological inflation is discussed. The School consisted of level-up courses intended for PhD students, as well as updating courses for postdocs and researchers. In addition, a few propaedeutical crash courses were organized to bridge the gaps in the attendance and to facilitate an active participation. The courses were held mostly on the blackboard. The audience was assumed to have at least a PhD student level either in phenomenological particle theory, in astroparticle physics or in field and string theory. One of the aims of the School was to bring together researchers of these different areas and to update them on one another's discipline. The School was divided in two workshops: Interface between Cosmology and Particle Physics Courses: W. GRIMUS and S. PETCOV: Neutrino Phenomenology A. MASIERO and F. FERUGLIO: Beyond the Standard Model P. ULLIO: Introduction to Dark Matter N. BILIC: Black holes phenomenology 2) Particle Physics, Gravity and String Theory Courses: R. BRANDENBERGER: Topics in Cosmology J. ZANELLI: Black holes physics C. NUNEZ: StringsGauge Correspondence A. JEVICKI: AdS/CFT G. DALL'AGATA: String vacua and moduli stabilization C. BURGESS: Cosmology and Strings G. CARDOSO: Black Holes and String Theory Seminars were held during the School: Seminars: D. DENEGRI: New physics at LHC D. WARK: Neutrino Experiments C. BACCIGALUPI: Review on Cosmological Experiments A. MUELLER: Experimental evidence of Black Holes S. LIBERATI: Astrophysical constraints on Lorentz violation In addition the following introductory courses were given during the first week: Introductory courses: M. BERTOLINI: Propaedeutical course in supersymmetry T. PROKOPEC: Propaedeutical course in cosmology G. BONELLI: Propaedeutical course of string theory M. SERONE: Propaedeutical course on physics of extra dimensions
Quantum Monte Carlo methods for nuclear physics
Carlson, J.; Gandolfi, S.; Pederiva, F.; Pieper, Steven C.; Schiavilla, R.; Schmidt, K. E.; Wiringa, R. B.
2015-09-09
Quantum Monte Carlo methods have proved valuable to study the structure and reactions of light nuclei and nucleonic matter starting from realistic nuclear interactions and currents. These ab-initio calculations reproduce many low-lying states, moments, and transitions in light nuclei, and simultaneously predict many properties of light nuclei and neutron matter over a rather wide range of energy and momenta. The nuclear interactions and currents are reviewed along with a description of the continuum quantum Monte Carlo methods used in nuclear physics. These methods are similar to those used in condensed matter and electronic structure but naturally include spin-isospin, tensor, spin-orbit, and three-body interactions. A variety of results are presented, including the low-lying spectra of light nuclei, nuclear form factors, and transition matrix elements. Low-energy scattering techniques, studies of the electroweak response of nuclei relevant in electron and neutrino scattering, and the properties of dense nucleonic matter as found in neutron stars are also described. Furthermore, a coherent picture of nuclear structure and dynamics emerges based upon rather simple but realistic interactions and currents.
Quantum Monte Carlo methods for nuclear physics
Carlson, J.; Gandolfi, S.; Pederiva, F.; Pieper, Steven C.; Schiavilla, R.; Schmidt, K. E.; Wiringa, R. B.
2015-09-09
Quantum Monte Carlo methods have proved valuable to study the structure and reactions of light nuclei and nucleonic matter starting from realistic nuclear interactions and currents. These ab-initio calculations reproduce many low-lying states, moments, and transitions in light nuclei, and simultaneously predict many properties of light nuclei and neutron matter over a rather wide range of energy and momenta. The nuclear interactions and currents are reviewed along with a description of the continuum quantum Monte Carlo methods used in nuclear physics. These methods are similar to those used in condensed matter and electronic structure but naturally include spin-isospin, tensor, spin-orbit,more » and three-body interactions. A variety of results are presented, including the low-lying spectra of light nuclei, nuclear form factors, and transition matrix elements. Low-energy scattering techniques, studies of the electroweak response of nuclei relevant in electron and neutrino scattering, and the properties of dense nucleonic matter as found in neutron stars are also described. Furthermore, a coherent picture of nuclear structure and dynamics emerges based upon rather simple but realistic interactions and currents.« less
Quantum Monte Carlo methods for nuclear physics
Carlson, Joseph A.; Gandolfi, Stefano; Pederiva, Francesco; Pieper, Steven C.; Schiavilla, Rocco; Schmidt, K. E,; Wiringa, Robert B.
2014-10-19
Quantum Monte Carlo methods have proved very valuable to study the structure and reactions of light nuclei and nucleonic matter starting from realistic nuclear interactions and currents. These ab-initio calculations reproduce many low-lying states, moments and transitions in light nuclei, and simultaneously predict many properties of light nuclei and neutron matter over a rather wide range of energy and momenta. We review the nuclear interactions and currents, and describe the continuum Quantum Monte Carlo methods used in nuclear physics. These methods are similar to those used in condensed matter and electronic structure but naturally include spin-isospin, tensor, spin-orbit, and three-bodymore » interactions. We present a variety of results including the low-lying spectra of light nuclei, nuclear form factors, and transition matrix elements. We also describe low-energy scattering techniques, studies of the electroweak response of nuclei relevant in electron and neutrino scattering, and the properties of dense nucleonic matter as found in neutron stars. A coherent picture of nuclear structure and dynamics emerges based upon rather simple but realistic interactions and currents.« less
Quantum Monte Carlo methods for nuclear physics
NASA Astrophysics Data System (ADS)
Carlson, J.; Gandolfi, S.; Pederiva, F.; Pieper, Steven C.; Schiavilla, R.; Schmidt, K. E.; Wiringa, R. B.
2015-07-01
Quantum Monte Carlo methods have proved valuable to study the structure and reactions of light nuclei and nucleonic matter starting from realistic nuclear interactions and currents. These ab initio calculations reproduce many low-lying states, moments, and transitions in light nuclei, and simultaneously predict many properties of light nuclei and neutron matter over a rather wide range of energy and momenta. The nuclear interactions and currents are reviewed along with a description of the continuum quantum Monte Carlo methods used in nuclear physics. These methods are similar to those used in condensed matter and electronic structure but naturally include spin-isospin, tensor, spin-orbit, and three-body interactions. A variety of results are presented, including the low-lying spectra of light nuclei, nuclear form factors, and transition matrix elements. Low-energy scattering techniques, studies of the electroweak response of nuclei relevant in electron and neutrino scattering, and the properties of dense nucleonic matter as found in neutron stars are also described. A coherent picture of nuclear structure and dynamics emerges based upon rather simple but realistic interactions and currents.
Summary of the particle physics and technology working group
Stephan Lammel et al.
2002-12-10
Progress in particle physics has been tightly related to technological advances during the past half century. Progress in technologies has been driven in many cases by the needs of particle physics. Often, these advances have benefited fields beyond particle physics: other scientific fields, medicine, industrial development, and even found commercial applications. The particle physics and technology working group of Snowmass 2001 reviewed leading-edge technologies recently developed or in the need of development for particle physics. The group has identified key areas where technological advances are vital for progress in the field, areas of opportunities where particle physics may play a principle role in fostering progress, and areas where advances in other fields may directly benefit particle physics. The group has also surveyed the technologies specifically developed or enhanced by research in particle physics that benefit other fields and/or society at large.
Photonic dark matter portal and quantum physics
NASA Astrophysics Data System (ADS)
A. Alavi, S.; S. Kazemian, F.
2016-02-01
We study a model of dark matter in which the hidden sector interacts with standard model particles via a hidden photonic portal. We investigate the effects of this new interaction on the hydrogen atom, including the Stark, Zeeman and hyperfine effects. Using the accuracy of the measurement of energy, we obtain an upper bound for the coupling constant of the model as f ⩽ 10-12. We also calculate the contribution from the hidden photonic portal to the anomalous magnetic moment of the muon as aμ ⩽ 2.2 × 10-23 (for the dark particle mass scale 100 MeV), which provides an important probe of physics beyond the standard model.
Topics in theoretical particle physics and cosmology
NASA Astrophysics Data System (ADS)
Salem, Michael Phillip
We first delve into particle phenomenology with a study of soft-collinear effective theory (SCET), an effective theory for Quantum Chromodynamics for when all particles are approximately on their light-cones. In particular, we study the matching of SCET(I) involving ultrasoft and collinear particles onto SCET(II) involving soft and collinear particles. We show that the modes in SCET(II) are sufficient to reproduce all of the infrared divergences of SCET(I), a result that was previously in contention.Next we move into early universe cosmology and study alternative mechanisms for generating primordial density perturbations. We study the inhomogeneous reheating mechanism and extend it to describe the scenario where the freeze-out process for a heavy particle is modulated by sub-dominant fields that received fluctuations during inflation. This scenario results in perturbations that are comparable to those generated by the original inhomogeneous reheating scenarios. In addition, we study yet another alternative to single field inflation whereby the curvature perturbation is generated by interactions at the end of inflation, as opposed to when inflaton modes exit the horizon. We clarify the circumstances under which this process can dominate over the standard one and we show that it may result in a spectrum with an observable level of non-Gaussianities.We then turn to studies of the landscape paradigm, which hypothesizes that the observed universe is just one among a multitude of possibilities that are realized in separate causal regions. Such a landscape has been used to explain the smallness of the cosmological constant, at least when only it scans across the landscape. We study the scenario where both the cosmological constant and the strength of gravity, parameterized by the effective Planck mass, scan across the landscape. We find that selection effects acting on the cosmological constant are significantly weaker in this scenario and we find the measured value of the Planck mass to be exponentially unlikely under certain plausible assumptions about the landscape. Finally, we study some other models of the landscape as part of a possible explanation for quark-sector flavor parameters in the Standard Model. In this picture quark Yukawa couplings result from overlap integrals involving quark and Higgs wavefunctions in compactified extra dimensions, and the values we measure result from random selection from a landscape of possibilities. We find that many of the salient features of the measured flavor parameters are typical of the landscape distribution.
Cognitive Mapping of Advanced Level Physics Students' Conceptions of Quantum Physics.
ERIC Educational Resources Information Center
Mashhadi, Azam; Woolnough, Brian
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…
Progress in Grid Computing for Particle Physics
NASA Astrophysics Data System (ADS)
Gardner, Robert
2006-04-01
We discuss progress in building and exploiting distributed Grid computing infrastructures with an emphasis on capabilities required for the next generation of particle physics experiments at the LHC. Associated with a persistent and reliable Grid infrastructure linking compute, storage and network resources together, experiments, organized as Virtual Organizations (VOs), are building information architectures that allow discovery, access, and manipulation of datasets and algorithms. We use the ATLAS experiment as a context for describing the scale and complexity of the processing tasks associated with large scale data analysis relevant to the LHC.
An introduction to cosmology and particle physics
Tenreiro, R.D.; Quiros, M.
1987-01-01
This book discusses, based on a series of lectures given by the authors at the Universidad Autonoma de Madrid, the relation between cosomology and particle physics at a pedagogical level. Contents: The Standard Cosmological Model; Determination of Cosmological Parameters; The Microwave Background Radiation; Primordial Nucleosynthesis; Formation of Large Scale Structure in the Universe Cosmological Bounds on the Parameters of Microphysical Theories; Finite Temperature Effective Potential and Phase Transitions; Problems of the Standard Big-Bang Model Inflationary Universe Scenario; The Dynamics of Inflation; Inflationary Models.
The Inverse Puzzle in Particle Physics
NASA Astrophysics Data System (ADS)
Kobach, Andrew C.
In this thesis, I present my attempts to address the Inverse Puzzle in particle physics, i.e., the challenges associated with determining the phenomenological implications of experimental data. In particular, this thesis discusses (1) the limitations of measuring the mass of dark matter at the LHC, (2) new methods for searching for heavy neutrinos, (3) relationships between lepton- and baryon-number violating processes from the perspective of grand unified theories, (4) possible indications of connections between dark matter and lepton flavor, and (5) the possibility of observing additional sources of CP-invariance violation at neutrino oscillation experiments.
Physics through the 1990s: Elementary-particle physics
NASA Technical Reports Server (NTRS)
1986-01-01
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.
Exploring flocking via quantum many-body physics techniques
NASA Astrophysics Data System (ADS)
Souslov, Anton; Loewe, Benjamin; Goldbart, Paul M.
2015-03-01
Flocking refers to the spontaneous breaking of spatial isotropy and time-reversal symmetries in collections of bodies such as birds, fish, locusts, bacteria, and artificial active systems. The transport of matter along biopolymers using molecular motors also involves the breaking of these symmetries, which in some cases are known to be broken explicitly. We study these classical nonequilibrium symmetry-breaking phenomena by means of models of many strongly interacting particles that hop on a periodic lattice. We employ a mapping between the classical and quantum dynamics of many-body systems, combined with tools from many-body theory. In particular, we examine the formation and properties of nematic and polar order in low-dimensional, strongly-interacting active systems using techniques familiar from fermionic systems, such as self-consistent field theory and bosonization. Thus, we find that classical active systems can exhibit analogs of quantum phenomena such as spin-orbit coupling, magnetism, and superconductivity. The models we study connect the physics of asymmetric exclusion processes to the spontaneous emergence of transport and flow, and also provide a soluble cousin of Vicsek's model system of self-propelled particles.
(Medium energy particle physics): Annual progress report
Nefkens, B.M.K.
1985-10-01
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.
Particle physics in the very early universe
NASA Technical Reports Server (NTRS)
Schramm, D. N.
1981-01-01
Events in the very early big bang universe in which elementary particle physics effects may have been dominant are discussed, with attention to the generation of a net baryon number by way of grand unification theory, and emphasis on the possible role of massive neutrinos in increasing current understanding of various cosmological properties and of the constraints placed on neutrino properties by cosmology. It is noted that when grand unification theories are used to describe very early universe interactions, an initially baryon-symmetrical universe can evolve a net baryon excess of 10 to the -9th to 10 to the -11th per photon, given reasonable parameters. If neutrinos have mass, the bulk of the mass of the universe may be in the form of leptons, implying that the form of matter most familiar to physical science may not be the dominant form of matter in the universe.
Particle Physics: A New Course for Schools and Colleges.
ERIC Educational Resources Information Center
Swinbank, Elizabeth
1992-01-01
Considers questions relating to the introduction of particle physics into post-GCSE (General Certificate of Secondary Education) courses. Describes a project that is producing teacher and student materials to support the teaching of particle physics at this level. Presents a proposed syllabus for a particle physics module. (KR)
Teaching and Understanding of Quantum Interpretations in Modern Physics Courses
ERIC Educational Resources Information Center
Baily, Charles; Finkelstein, Noah D.
2010-01-01
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
Many-particle quantum graphs and Bose-Einstein condensation
NASA Astrophysics Data System (ADS)
Bolte, Jens; Kerner, Joachim
2014-06-01
In this paper, we propose quantum graphs as one-dimensional models with a complex topology to study Bose-Einstein condensation and phase transitions in a rigorous way. We first investigate non-interacting many-particle systems on quantum graphs and provide a complete classification of systems that exhibit Bose-Einstein condensation. We then consider models of interacting particles that can be regarded as a generalisation of the well-known Tonks-Girardeau gas. Here, our principal result is that no phase transitions occur in bosonic systems with repulsive hardcore interactions, indicating an absence of Bose-Einstein condensation.
Quantum principles and free particles. [evaluation of partitions
NASA Technical Reports Server (NTRS)
1976-01-01
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.
Lagrangian dynamics for classical, Brownian, and quantum mechanical particles
NASA Astrophysics Data System (ADS)
Pavon, Michele
1996-07-01
In the framework of Nelson's stochastic mechanics [E. Nelson, Dynamical Theories of Brownian Motion (Princeton University, Princeton, 1967); F. Guerra, Phys. Rep. 77, 263 (1981); E. Nelson, Quantum Fluctuations (Princeton University, Princeton, 1985)] we seek to develop the particle counterpart of the hydrodynamic results of M. Pavon [J. Math. Phys. 36, 6774 (1995); Phys. Lett. A 209, 143 (1995)]. In particular, a first form of Hamilton's principle is established. We show that this variational principle leads to the correct equations of motion for the classical particle, the Brownian particle in thermodynamical equilibrium, and the quantum particle. In the latter case, the critical process q satisfies a stochastic Newton law. We then introduce the momentum process p, and show that the pair (q,p) satisfies canonical-like equations.
Quantum Zeno effect for a free-moving particle
NASA Astrophysics Data System (ADS)
Porras, Miguel A.; Luis, Alfredo; Gonzalo, Isabel
2014-12-01
Although the quantum Zeno effect takes its name from Zeno's arrow paradox, the effect of frequently observing the position of a freely moving particle on its motion has not been analyzed in detail in the frame of standard quantum mechanics. We study the evolution of a moving free particle while monitoring whether it lingers in a given region of space, and explain the dependence of the lingering probability on the frequency of the measurements and the initial momentum of the particle. Stopping the particle entails the emergence of Schrödinger cat states during the observed evolution, closely connected to the high-order diffraction modes in Fabry-Pérot optical resonators.
Teaching and understanding of quantum interpretations in modern physics courses
NASA Astrophysics Data System (ADS)
Baily, Charles; Finkelstein, Noah D.
2010-06-01
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.
Attention, Intention, and Will in Quantum Physics
Stapp, H.P.
1999-05-01
How is mind related to matter? This ancient question inphilosophy is rapidly becoming a core problem in science, perhaps themost important of all because it probes the essential nature of manhimself. The origin of the problem is a conflict between the mechanicalconception of human beings that arises from the precepts of classicalphysical theory and the very different idea that arises from ourintuition: the former reduces each of us to an automaton, while thelatter allows our thoughts to guide our actions. The dominantcontemporary approaches to the problem attempt to resolve this conflictby clinging to the classical concepts, and trying to explain away ourmisleading intuition. But a detailed argument given here shows why, in ascientific approach to this problem, it is necessary to use the morebasic principles of quantum physics, which bring the observer into thedynamics, rather than to accept classical precepts that are profoundlyincorrect precisely at the crucial point of the role of humanconsciousness in the dynamics of human brains. Adherence to the quantumprinciples yields a dynamical theory of the mind/brain/body system thatis in close accord with our intuitive idea of what we are. In particular,the need for a self-observing quantum system to pose certain questionscreates a causal opening that allowsmind/brain dynamics to have threedistinguishable but interlocked causal processes, one micro-local, onestochastic, and the third experiential. Passing to the classical limit inwhich the critical difference between zero and the finite actual value ofPlanck's constant is ignored not only eliminates the chemical processesthat are absolutely crucial to the functioning of actual brains, itsimultaneously blinds the resulting theoretical construct to the physicalfine structure wherein the effect of mind on matter lies: the use of thislimit in this context is totally unjustified from a physicsperspective.
Quantum Field Theory in Condensed Matter Physics
NASA Astrophysics Data System (ADS)
Tsvelik, Alexei M.
2007-01-01
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.
Probing Planckian physics in de Sitter space with quantum correlations
Feng, Jun; Zhang, Yao-Zhong; Gould, Mark D.; Fan, Heng; Sun, Cheng-Yi; Yang, Wen-Li
2014-12-15
We study the quantum correlation and quantum communication channel of both free scalar and fermionic fields in de Sitter space, while the Planckian modification presented by the choice of a particular α-vacuum has been considered. We show the occurrence of degradation of quantum entanglement between field modes for an inertial observer in curved space, due to the radiation associated with its cosmological horizon. Comparing with standard Bunch–Davies choice, the possible Planckian physics causes some extra decrement on the quantum correlation, which may provide the means to detect quantum gravitational effects via quantum information methodology in future. Beyond single-mode approximation, we construct proper Unruh modes admitting general α-vacua, and find a convergent feature of both bosonic and fermionic entanglements. In particular, we show that the convergent points of fermionic entanglement negativity are dependent on the choice of α. Moreover, an one-to-one correspondence between convergent points H{sub c} of negativity and zeros of quantum capacity of quantum channels in de Sitter space has been proved. - Highlights: • Quantum correlation and quantum channel in de Sitter space are studied. • Gibbons–Hawking effect causes entanglement degradation for static observer. • Planckian physics causes extra decrement on quantum correlation. • Convergent feature of negativity relies on the choice of alpha-vacua. • Link between negativity convergence and quantum channel capacity is given.
Decays of particles with exotic quantum numbers
Willey, R.S.
1983-07-01
The most convincing place to find a glueball would be in a channel with exotic quantum numbers (J/sup P/C = 0/sup - -/, even/sup + -/, odd/sup - +/). We enumerate the allowed and forbidden few-body decay modes of such exotic mesons. In the particular case of the 0/sup + -/, the set of allowed few-body decay modes is itself a unique signature. For other J/sup P/C values the signature depends on somewhat more detailed characteristics of the allowed decays, which we enumerate.
Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou
2013-05-20
We propose an efficient protocol for optimizing the physical implementation of three-qubit quantum error correction with spatially separated quantum dot spins via virtual-photon-induced process. In the protocol, each quantum dot is trapped in an individual cavity and each two cavities are connected by an optical fiber. We propose the optimal quantum circuits and describe the physical implementation for correcting both the bit flip and phase flip errors by applying a series of one-bit unitary rotation gates and two-bit quantum iSWAP gates that are produced by the long-range interaction between two distributed quantum dot spins mediated by the vacuum fields of the fiber and cavity. The protocol opens promising perspectives for long distance quantum communication and distributed quantum computation networks. PMID:23736467
Single particle density of trapped interacting quantum gases
Bala, Renu; Bosse, J.; Pathak, K. N.
2015-05-15
An expression for single particle density for trapped interacting gases has been obtained in first order of interaction using Green’s function method. Results are easily simplified for homogeneous quantum gases and are found to agree with famous results obtained by Huang-Yang-Luttinger and Lee-Yang.
Quantum Tic-Tac-Toe as Metaphor for Quantum Physics
NASA Astrophysics Data System (ADS)
Goff, Allan; Lehmann, Dale; Siegel, Joel
2004-02-01
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.
Particle physics confronts the solar neutrino problem
Pal, P.B.
1991-06-01
This review has four parts. In Part I, we describe the reactions that produce neutrinos in the sun and the expected flux of those neutrinos on the earth. We then discuss the detection of these neutrinos, and how the results obtained differ from the theoretical expectations, leading to what is known as the solar neutrino problem. In Part II, we show how neutrino oscillations can provide a solution to the solar neutrino problem. This includes vacuum oscillations, as well as matter enhanced oscillations. In Part III, we discuss the possibility of time variation of the neutrino flux and how a magnetic moment of the neutrino can solve the problem. WE also discuss particle physics models which can give rise to the required values of magnetic moments. In Part IV, we present some concluding remarks and outlook for the recent future.
Some calculator programs for particle physics
NASA Astrophysics Data System (ADS)
Whol, C. G.
1982-01-01
Seven calculator programs that do simple chores that arise in elementary particle physics are given. LEGENDRE evaluates the Legendre polynomial series. ASSOCIATED LEGENDRE evaluates the first associated Legendre polynomial series. CONFIDENCE calculates confidence levels for chi(2), Gaussian, or Poisson probability distributions. TWO BODY calculates the c.m. energy, the initial and final state c.m. momenta, and the extreme values of t and u for a two body reaction. ELLIPSE calculates coordinates of points for drawing an ellipse plot showing the kinematics of a two body reaction or decay. DALITZ RECTANGULAR calculates coordinates of points on the boundary of a rectangular Dalitz plot. DALITZ TRIANGULAR calculates coordinates of points on the boundary of a triangular Dalitz plot. There are short versions of CONFIDENCE (EVEN N and POISSON) that calculate confidence levels for the even degree of freedom chi(2) and the Poisson cases. The programs are written for the HP-97 calculator.
Quantum maximum entropy principle for a system of identical particles
Trovato, M.; Reggiani, L.
2010-02-15
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.
Matter and Interactions: A Particle Physics Perspective
ERIC Educational Resources Information Center
Organtini, Giovanni
2011-01-01
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
Matter and Interactions: A Particle Physics Perspective
ERIC Educational Resources Information Center
Organtini, Giovanni
2011-01-01
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…
Particle physics---Experimental. Annual progress report
Lord, J.J.; Boynton, P.E.; Burnett, T.H.; Wilkes, R.J.
1991-08-21
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.
Multiparty quantum key agreement with single particles
NASA Astrophysics Data System (ADS)
Liu, Bin; Gao, Fei; Huang, Wei; Wen, Qiao-yan
2013-04-01
Two conditions must be satisfied in a secure quantum key agreement (QKA) protocol: (1) outside eavesdroppers cannot gain the generated key without introducing any error; (2) the generated key cannot be determined by any non-trivial subset of the participants. That is, a secure QKA protocol can not only prevent the outside attackers from stealing the key, but also resist the attack from inside participants, i.e. some dishonest participants determine the key alone by illegal means. How to resist participant attack is an aporia in the design of QKA protocols, especially the multi-party ones. In this paper we present the first secure multiparty QKA protocol against both outside and participant attacks. Further more, we have proved its security in detail.
Quantum Zeno effect and quantum Zeno paradox in atomic physics
NASA Astrophysics Data System (ADS)
Block, Ellen; Berman, P. R.
1991-08-01
Itano and co-workers [Wayne M. Itano, D. J. Heinzen, J. J. Bollinger, and D. J. Wineland, Phys. Rev. A 41, 2295 (1990)] have recently reported the experimental verification of the quantum Zeno effect, which is the inhibition of a quantum transition by frequent measurements. In this article, we offer an alternative interpretation of the quantum Zeno effect. We show that an analysis of the dynamics of the full three-level system gives the same result. There is no need to assume explicitly that the wave function has collapsed, nor even to assume that an ideal measurement has been made. In addition, we differentiate between what has been referred to as the quantum Zeno effect and what has been termed the quantum Zeno paradox. The former is the inhibition of induced transitions, and the latter is the, as yet experimentally unobserved, inhibition of spontaneous decay. Our interpretation, which emphasizes the ``measurement''-induced interruption of atomic-state coherences as the cause of inhibited quantum transitions, suggests a resolution to the quantum Zeno paradox. The theoretical limit of continuous observation is discussed.
Quantum-Behaved Particle Swarm Optimization with Chaotic Search
NASA Astrophysics Data System (ADS)
Yang, Kaiqiao; Nomura, Hirosato
The chaotic search is introduced into Quantum-behaved Particle Swarm Optimization (QPSO) to increase the diversity of the swarm in the latter period of the search, so as to help the system escape from local optima. Taking full advantages of the characteristics of ergodicity and randomicity of chaotic variables, the chaotic search is carried out in the neighborhoods of the particles which are trapped into local optima. The experimental results on test functions show that QPSO with chaotic search outperforms the Particle Swarm Optimization (PSO) and QPSO.
Linking Quantum Mechanics to Freshman Physics
NASA Astrophysics Data System (ADS)
Vandegrift, Guy
1998-10-01
First-year quantum mechanics can be linked to introductory physics. One example is the Mossbauer effect, which is explained using a simple solution to Schrodinger's equation involving the Dirac delta function. Generalization to N coupled harmonic oscillators shows that the equality of the forces exerted by winner and loser in the game of "tug-of-war" is only an approximation because Newton's third law of motion is not valid (unless phonon momentum is considered). Another example is a treatment of the Gaussian wavepacket which involves less algebra than found in standard textbooks, yet shows that the peak moves according to the familiar equation of motion x = vt + (1/2)at^2 when the applied force is uniform. Finally, a rendition of "Turkey in the Straw" on the viola illustrates Heisenberg's uncertainty principle, which can be written in the less mysterious form, f=(N+-.1)/T , where N cycles are counted in T seconds. Students experience this uncertainty as they try to measure the frequency of a stretched slinky.
One-dimensional chain of quantum molecule motors as a mathematical physics model for muscle fibers
NASA Astrophysics Data System (ADS)
Si, Tie-Yan
2015-12-01
A quantum chain model of multiple molecule motors is proposed as a mathematical physics theory for the microscopic modeling of classical force-velocity relation and tension transients in muscle fibers. The proposed model was a quantum many-particle Hamiltonian to predict the force-velocity relation for the slow release of muscle fibers, which has not yet been empirically defined and was much more complicated than the hyperbolic relationships. Using the same Hamiltonian model, a mathematical force-velocity relationship was proposed to explain the tension observed when the muscle was stimulated with an alternative electric current. The discrepancy between input electric frequency and the muscle oscillation frequency could be explained physically by the Doppler effect in this quantum chain model. Further more, quantum physics phenomena were applied to explore the tension time course of cardiac muscle and insect flight muscle. Most of the experimental tension transient curves were found to correspond to the theoretical output of quantum two- and three-level models. Mathematical modeling electric stimulus as photons exciting a quantum three-level particle reproduced most of the tension transient curves of water bug Lethocerus maximus. Project supported by the Fundamental Research Foundation for the Central Universities of China.
Particle Physics in a Season of Change
Quigg, Chris
2012-02-01
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.
The Second Law and Quantum Physics
NASA Astrophysics Data System (ADS)
Bennett, Charles H.
2008-08-01
In this talk, I discuss the mystery of the second law and its relation to quantum information. There are many explanations of the second law, mostly satisfactory and not mutually exclusive. Here, I advocate quantum mechanics and quantum information as something that, through entanglement, helps resolve the paradox or the puzzle of the origin of the second law. I will discuss the interpretation called quantum Darwinism and how it helps explain why our world seems so classical, and what it has to say about the permanence or transience of information. And I will discuss a simple model illustrating why systems away from thermal equilibrium tend to be more complicated.
Time and a physical Hamiltonian for quantum gravity.
Husain, Viqar; Pawłowski, Tomasz
2012-04-01
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
Long-time behavior of many-particle quantum decay
NASA Astrophysics Data System (ADS)
Del Campo, A.
2011-07-01
While exponential decay is ubiquitous in nature, deviations at both short and long times are dictated by quantum mechanics. Nonexponential decay is known to arise due to the possibility of reconstructing the initial state from the decaying products. We discuss the quantum decay dynamics by tunneling of a many-particle system, characterizing the long-time nonexponential behavior of the nonescape and survival probabilities. The effects of contact interactions and quantum statistics are described. It is found that, whereas for noninteracting bosons the long-time decay follows a power law with an exponent linear in the number of particles N, the exponent becomes quadratic in N in the fermionic case. The same results apply to strongly interacting many-body systems related by the generalized Bose-Fermi duality. The faster fermionic decay can be traced back to the effective hard-core interactions between particles, which are as well the decaying products, and exhibit spatial antibunching which hinders the reconstruction of the initial unstable state. The results are illustrated with a paradigmatic model of quantum decay from a trap allowing leaks by tunneling, whose dynamics is described exactly by means of an expansion in resonant states.
The Physical Principles of Particle Detectors.
ERIC Educational Resources Information Center
Jones, Goronwy Tudor
1991-01-01
Describes the use of a particle detector, an instrument that records the passage of particles through it, to determine the mass of a particle by measuring the particles momentum, speed, and kinetic energy. An appendix discusses the limits on the impact parameter. (MDH)
Are quantum-mechanical-like models possible, or necessary, outside quantum physics?
NASA Astrophysics Data System (ADS)
Plotnitsky, Arkady
2014-12-01
This article examines some experimental conditions that invite and possibly require recourse to quantum-mechanical-like mathematical models (QMLMs), models based on the key mathematical features of quantum mechanics, in scientific fields outside physics, such as biology, cognitive psychology, or economics. In particular, I consider whether the following two correlative features of quantum phenomena that were decisive for establishing the mathematical formalism of quantum mechanics play similarly important roles in QMLMs elsewhere. The first is the individuality and discreteness of quantum phenomena, and the second is the irreducibly probabilistic nature of our predictions concerning them, coupled to the particular character of the probabilities involved, as different from the character of probabilities found in classical physics. I also argue that these features could be interpreted in terms of a particular form of epistemology that suspends and even precludes a causal and, in the first place, realist description of quantum objects and processes. This epistemology limits the descriptive capacity of quantum theory to the description, classical in nature, of the observed quantum phenomena manifested in measuring instruments. Quantum mechanics itself only provides descriptions, probabilistic in nature, concerning numerical data pertaining to such phenomena, without offering a physical description of quantum objects and processes. While QMLMs share their use of the quantum-mechanical or analogous mathematical formalism, they may differ by the roles, if any, the two features in question play in them and by different ways of interpreting the phenomena they considered and this formalism itself. This article will address those differences as well.
Research accomplishments and future goals in particle physics
Whitaker, J.S.
1990-01-05
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.
Particle astronomy and particle physics from the moon - The particle observatory
NASA Technical Reports Server (NTRS)
Wilson, Thomas L.
1990-01-01
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.
Spacetime alternatives in the quantum mechanics of a relativistic particle
Whelan, J.T. Isaac Newton Institute for Mathematical Sciences, 20 Clarkson Road, Cambridge, CB3 0EH )
1994-11-15
Hartle's generalized quantum mechanics formalism is used to examine spacetime coarse grainings, i.e., sets of alternatives defined with respect to a region extended in time as well as space, in the quantum mechanics of a free relativistic particle. For a simple coarse graining and suitable initial conditions, tractable formulas are found for branch wave functions. Despite the nonlocality of the positive-definite version of the Klein-Gordon inner product, which means that nonoverlapping branches are not sufficient to imply decoherence, some initial conditions are found to give decoherence and allow the consistent assignment of probabilities.
From Dualism to Unity in Quantum Physics
NASA Astrophysics Data System (ADS)
Landé, Alfred
2016-02-01
Preface; Introduction; 1. Causality, chance, continuity; 2. States, observables, probabilities; 3. The metric law of probabilities; 4. Quantum dynamics; 5. Quantum fact and fiction; Retrospect. From dualism to unity, from positivism to realism; Appendix 1. Survey of elementary postulates; Appendix 2. Two problems of uniqueness; References; Index.
Quantum physics: Photons paired with phonons
NASA Astrophysics Data System (ADS)
Blencowe, Miles
2016-02-01
The force exerted by light on an object has been used to pair photons with quantum units of mechanical vibration. This paves the way for mechanical oscillators to act as interfaces between photons and other quantum systems. See Letter p.313
Teaching and Understanding of Quantum Interpretations in Modern Physics Courses
ERIC Educational Resources Information Center
Baily, Charles; Finkelstein, Noah D.
2010-01-01
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…
NASA Astrophysics Data System (ADS)
Altarelli, Guido
2012-03-01
The LHC results released so far have very much restricted the possible range for the Standard Model Higgs boson mass. Moreover some indications for a signal at a mass around 125 GeV have been found. At the same time, no clear evidence for new physics has emerged from the LHC data. We discuss the impact of these results on our understanding of particle physics. The presently allowed window for the Higgs mass and the negative results for exotic particles are compatible with both the Standard model and its Supersymmetric extensions but imply considerable restrictions and need a substantial amount of fine tuning in all cases. We discuss the options that remain open and the perspectives for the near future.
Particle physics: CP violation in hyperon decays
Longo, Michael J.
2000-10-31
The primary research activities under this grant were in E871 (HyperCP) at Fermilab, a search for CP violation in hyperon decays which completed data taking in January, 2000. HyperCP is an experiment designed to perform a sensitive search for direct CP violation in the decays of cascade ({Xi}) and {Lambda} hyperons by looking for an asymmetry between particle and antiparticle decay parameters. The experiment is expected to achieve a sensitivity {approx}10{sup -4} in the decay parameters. Standard model predictions for this CP-violating asymmetry range from 0.3 to 5 x 10{sup -4}. A difference between the decay parameters for particle and antiparticle is direct evidence that CP symmetry is violated. A non-zero asymmetry would be the first evidence for CP violation outside of the K{sup o} system. Recent results from KTeV indicate a direct CP violation in K{sup o} decays, which suggests that CP violation will appear in other decays. In addition, we will look at a number of rare hyperon decays involving muons. These probe important new physics topics such as Majorana neutrinos and lepton number violating processes. The latter are of great current interest because new evidence for neutrino oscillations indicate lepton flavor violation does occur. Our data will lead to an improvement in the limits on branching ratios for these processes typically by three to four orders-of-magnitude. The muon detector construction and data resulting from it have been the responsibility of the Michigan group. We are now leading the analysis of the rare muon-related decay modes, and were responsible for the muon system and beam monitor upgrades for the 1999 run.
Common non-Fermi liquid phases in quantum impurity physics
NASA Astrophysics Data System (ADS)
Logan, David E.; Tucker, Adam P.; Galpin, Martin R.
2014-08-01
We study correlated quantum impurity models that undergo a local quantum phase transition (QPT) from a strong coupling, Fermi liquid phase to a non-Fermi liquid phase with a globally doubly degenerate ground state. Our aim is to establish what can be shown exactly about such "local moment" (LM) phases, of which the permanent (zero-field) local magnetization is a hallmark, and an order parameter for the QPT. A description of the zero-field LM phase is shown to require two distinct self-energies, which reflect the broken symmetry nature of the phase and together determine the single self-energy of standard field theory. Distinct Friedel sum rules for each phase are obtained, via a Luttinger theorem embodied in the vanishing of appropriate Luttinger integrals. By contrast, the standard Luttinger integral is nonzero in the LM phase but found to have universal magnitude. A range of spin susceptibilites are also considered, including that corresponding to the local order parameter, whose exact form is shown to be RPA-like, and to diverge as the QPT is approached. Particular attention is given to the pseudogap Anderson model, including the basic physical picture of the transition, the low-energy behavior of single-particle dynamics, the quantum critical point itself, and the rather subtle effect of an applied local field. A two-level impurity model that undergoes a QPT ("singlet-triplet") to an underscreened LM phase is also considered, for which we derive on general grounds some key results for the zero-bias conductance in both phases.
Inverse Problems in Classical and Quantum Physics
NASA Astrophysics Data System (ADS)
Almasy, Andrea A.
2009-12-01
The subject of this thesis is in the area of Applied Mathematics known as Inverse Problems. Inverse problems are those where a set of measured data is analysed in order to get as much information as possible on a model which is assumed to represent a system in the real world. We study two inverse problems in the fields of classical and quantum physics: QCD condensates from tau-decay data and the inverse conductivity problem. We use a functional method which allows us to extract within rather general assumptions phenomenological parameters of QCD (the condensates) from a comparison of the time-like experimental data with asymptotic space-like results from theory. The price to be paid for the generality of assumptions is relatively large errors in the values of the extracted parameters. Although we do not claim that our method is superior to other approaches, we hope that our results lend additional confidence to the numerical results obtained with the help of methods based on QCD sum rules. In this thesis, also two approaches of EIT image reconstruction are proposed. The first is based on reformulating the inverse problem in terms of integral equations. This method uses only a single set of measurements for the reconstruction. The second approach is an algorithm based on linearisation which uses more then one set of measurements. A promising result is that one can qualitatively reconstruct the conductivity inside the cross-section of a human chest. Even though the human volunteer is neither two-dimensional nor circular, such reconstructions can be useful in medical applications: monitoring for lung problems such as accumulating fluid or a collapsed lung and noninvasive monitoring of heart function and blood flow.
Single particle in quantum gravity and Braunstein-Ghosh-Severini entropy of a spin network
Rovelli, Carlo; Vidotto, Francesca
2010-02-15
Passerini and Severini have recently shown that the Braunstein-Ghosh-Severini (BGS) entropy S{sub {Gamma}}=-Tr[{rho}{sub {Gamma}}log{rho}{sub {Gamma}}] of a certain density matrix {rho}{sub {Gamma}} naturally associated to a graph {Gamma}, is maximized, among all graphs with a fixed number of links and nodes, by regular graphs. We ask if this result can play a role in quantum gravity, and be related to the apparent regularity of the physical geometry of space. We show that in loop quantum gravity the matrix {rho}{sub {Gamma}} is precisely the Hamiltonian operator (suitably normalized) of a nonrelativistic quantum particle interacting with the quantum gravitational field, if we restrict elementary area and volume eigenvalues to a fixed value. This operator provides a spectral characterization of the physical geometry, and can be interpreted as a state describing the spectral information about the geometry available when geometry is measured by its physical interaction with matter. It is then tempting to interpret its BGS entropy S{sub {Gamma}} as a genuine physical entropy: we discuss the appeal and the difficulties of this interpretation.
Quantum-Carnot engine for particle confined to cubic potential
NASA Astrophysics Data System (ADS)
Sutantyo, Trengginas Eka P.; Belfaqih, Idrus H.; Prayitno, T. B.
2015-09-01
Carnot cycle consists of isothermal and adiabatic processes which are reversible. Using analogy in quantum mechanics, these processes can be well explained by replacing variables in classical process with a quantum system. Quantum system which is shown in this paper is a particle that moves under the influence of a cubic potential which is restricted only to the state of the two energy levels. At the end, the efficiency of the system is shown as a function of the width ratio between the initial conditions and the farthest wall while expanding. Furthermore, the system efficiency will be considered 1D and 2D cases. The providing efficiencies are different due to the influence of the degeneration of energy and the degrees of freedom of the system.
Quantum-Carnot engine for particle confined to cubic potential
Sutantyo, Trengginas Eka P. Belfaqih, Idrus H. Prayitno, T. B.
2015-09-30
Carnot cycle consists of isothermal and adiabatic processes which are reversible. Using analogy in quantum mechanics, these processes can be well explained by replacing variables in classical process with a quantum system. Quantum system which is shown in this paper is a particle that moves under the influence of a cubic potential which is restricted only to the state of the two energy levels. At the end, the efficiency of the system is shown as a function of the width ratio between the initial conditions and the farthest wall while expanding. Furthermore, the system efficiency will be considered 1D and 2D cases. The providing efficiencies are different due to the influence of the degeneration of energy and the degrees of freedom of the system.
Friction and particle-hole pairs. [in dissipative quantum phenomena
NASA Technical Reports Server (NTRS)
Guinea, F.
1984-01-01
The effect induced by dissipation on quantum phenomena has recently been considered, taking into account as a starting point a phenomenological Hamiltonian in which the environment is simulated by an appropriately chosen set of harmonic oscillators. It is found that this approach should be adequate to describe the low-energy behavior of a wide class of environments. The present investigation is concerned with an analysis of the case in which the environment is a gas (or liquid) of fermions, and the relevant low-energy excitations are particle-hole pairs. A study is conducted regarding the extent to which the quantum results obtained for harmonic oscillators are also valid in the considered situation. Linear-response theory is used to derive an effective action which describes the motion of an external particle coupled to a normal Fermi fluid.
Role of quantum statistics in multi-particle decay dynamics
Marchewka, Avi; Granot, Er’el
2015-04-15
The role of quantum statistics in the decay dynamics of a multi-particle state, which is suddenly released from a confining potential, is investigated. For an initially confined double particle state, the exact dynamics is presented for both bosons and fermions. The time-evolution of the probability to measure two-particle is evaluated and some counterintuitive features are discussed. For instance, it is shown that although there is a higher chance of finding the two bosons (as oppose to fermions, and even distinguishable particles) at the initial trap region, there is a higher chance (higher than fermions) of finding them on two opposite sides of the trap as if the repulsion between bosons is higher than the repulsion between fermions. The results are demonstrated by numerical simulations and are calculated analytically in the short-time approximation. Furthermore, experimental validation is suggested.
Classical foundations of many-particle quantum chaos
NASA Astrophysics Data System (ADS)
Gutkin, Boris; Osipov, Vladimir
2016-02-01
In the framework of semiclassical theory the universal properties of quantum systems with classically chaotic dynamics can be accounted for through correlations between partner periodic orbits with small action differences. So far, however, the scope of this approach has been mainly limited to systems of a few particles with low-dimensional phase spaces. In the present work we consider N-particle chaotic systems with local homogeneous interactions, where N is not necessarily small. Based on a model of coupled cat maps we demonstrate emergence of a new mechanism for correlation between periodic orbit actions. In particular, we show the existence of partner orbits which are specific to many-particle systems. For a sufficiently large N these new partners dominate the spectrum of correlating periodic orbits and seem to be necessary for construction of a consistent many-particle semiclassical theory.
Physics of quantum well solar cells
NASA Astrophysics Data System (ADS)
Ekins-Daukes, N. J.; Adams, J.; Ballard, I. M.; Barnham, K. W. J.; Browne, B.; Connolly, J. P.; Tibbits, T.; Hill, G.; Roberts, J. S.
2009-02-01
Incorporating quantum wells into multi-junction III-V solar cells provides a means of adjusting the absorption edge of the component junctions. Further, by using alternating compressive and tensile materials, a strain-balanced stack of quantum well and barrier layers can be grown, defect free, providing absorption-edge / lattice parameter combinations that are inaccessible using bulk materials. Incomplete absorption in the quantum wells has been addressed using a distributed Bragg reflector, extending the optical path length through the cell and enabling photon recycling to take place. State of the art single-junction quantum well solar cells have now reached an efficiency of 27.3% under 500X solar concentration and are projected to reach 34% in a double junction configuration.
Teaching Elementary Particle Physics, Part II
ERIC Educational Resources Information Center
Hobson, Art
2011-01-01
In order to explain certain features of radioactive beta decay, Wolfgang Pauli suggested in 1930 that the nucleus emitted, in addition to a beta particle, another particle of an entirely new type. The hypothesized particle, dubbed the neutrino, would not be discovered experimentally for another 25 years. It's not easy to detect neutrinos, because
Teaching Elementary Particle Physics, Part II
ERIC Educational Resources Information Center
Hobson, Art
2011-01-01
In order to explain certain features of radioactive beta decay, Wolfgang Pauli suggested in 1930 that the nucleus emitted, in addition to a beta particle, another particle of an entirely new type. The hypothesized particle, dubbed the neutrino, would not be discovered experimentally for another 25 years. It's not easy to detect neutrinos, because…
Colloquium: Majorana fermions in nuclear, particle, and solid-state physics
NASA Astrophysics Data System (ADS)
Elliott, Steven R.; Franz, Marcel
2015-01-01
Ettore Majorana (1906-1938) disappeared while traveling by ship from Palermo to Naples in 1938. His fate has never been fully resolved and several articles have been written that explore the mystery itself. His demise intrigues us still today because of his seminal work, published the previous year, that established symmetric solutions to the Dirac equation that describe a fermionic particle that is its own antiparticle. This work has long had a significant impact in neutrino physics, where this fundamental question regarding the particle remains unanswered. But the formalism he developed has found many uses as there are now a number of candidate spin-1 /2 neutral particles that may be truly neutral with no quantum number to distinguish them from their antiparticles. If such particles exist, they will influence many areas of nuclear and particle physics. Most notably the process of neutrinoless double beta decay can exist only if neutrinos are massive Majorana particles. Hence, many efforts to search for this process are underway. Majorana's influence does not stop with particle physics, however, even though that was his original consideration. The equations he derived also arise in solid-state physics where they describe electronic states in materials with superconducting order. Of special interest here is the class of solutions of the Majorana equation in one and two spatial dimensions at exactly zero energy. These Majorana zero modes are endowed with some remarkable physical properties that may lead to advances in quantum computing and, in fact, there is evidence that they have been experimentally observed. This Colloquium first summarizes the basics of Majorana's theory and its implications. It then provides an overview of the rich experimental programs trying to find a fermion that is its own antiparticle in nuclear, particle, and solid-state physics.
NASA Astrophysics Data System (ADS)
Ayene, Mengesha; Kriek, Jeanne; Damtie, Baylie
2011-12-01
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.
Variance of the Quantum Dwell Time for a Nonrelativistic Particle
NASA Technical Reports Server (NTRS)
Hahne, Gerhard
2012-01-01
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, . . ., 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.
NASA Astrophysics Data System (ADS)
Santos, Jonas F. G.; Bernardini, Alex E.; Bastos, Catarina
2015-11-01
Novel quantization properties related to the state vectors and the energy spectrum of a two-dimensional system of free particles are obtained in the framework of noncommutative (NC) quantum mechanics (QM) supported by the Weyl-Wigner formalism. Besides reproducing the magnetic field aspect of a Zeeman-like effect, the momentum space NC parameter introduces mutual information properties quantified by the quantum purity related to the relevant coordinates of the corresponding Hilbert space. Supported by the QM in the phase-space, the thermodynamic limit is obtained, and the results are extended to three-dimensional systems. The noncommutativity imprints on the thermodynamic variables related to free particles are identified and, after introducing some suitable constraints to fix an axial symmetry, the analysis is extended to two- and- three dimensional quantum rotor systems, for which the quantization aspects and the deviation from standard QM results are verified.
Families of Particles with Different Masses in PT-Symmetric Quantum Field Theory
Bender, Carl M.; Klevansky, S. P.
2010-07-16
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.
Teaching Quantum Physics in Upper Secondary School in France:
NASA Astrophysics Data System (ADS)
Lautesse, Philippe; Vila Valls, Adrien; Ferlin, Fabrice; Héraud, Jean-Loup; Chabot, Hugues
2015-10-01
One of the main problems in trying to understand quantum physics is the nature of the referent of quantum theory. This point is addressed in the official French curriculum in upper secondary school. Starting in 2012, after about 20 years of absence, quantum physics has returned to the national program. On the basis of the historical construction of quantum physics, we identify two epistemological positions with respect to this problem: The first one (close to the so-called Copenhagen school) is termed the conservative position and the second one (associated with the work of Bunge and Lévy-Leblond) the innovative position. We then analyze French textbooks used by teachers, in order to reveal the implicit positions adopted. We conclude with the idea that highlighting these epistemological choices can help teachers reflect upon the historical and epistemological roots of quantum physics. Such an analysis can contribute to developing and implementing appropriate teaching sequences for quantum physics. We explore the application of these epistemological positions to Young's paradigmatic experiment using the double slits.
Exploring the Physics of Semiconductor Quantum Dots using Circuit Quantum Electrodynamics
NASA Astrophysics Data System (ADS)
Stockklauser, Anna; Maisi, Ville; Ihn, Thomas; Ensslin, Klaus; Wallraff, Andreas
2015-03-01
Semiconductor quantum dots and superconducting qubits both possess excitations in the microwave domain for which a wide range of novel approaches to create, store, manipulate and detect individual photons have been developed. A key ingredient are coplanar waveguide resonators in which the field energy of an excitation is distributed over a small mode volume. This feature creates sizable electromagnetic fields at the level of individual microwave photons mediating strong electromagnetic interactions with a variety of quantum systems. In an approach known as circuit quantum electrodynamics (QED) we both probe fundamental quantum optical effects and demonstrate basic features of quantum information processing. In this presentation, I will discuss experiments exploring the physics of semiconductor quantum dots in the context of circuit QED. We investigate the coherent dipole coupling of double dots to microwave photons and detect radiation emitted from the dots in inelastic electron tunneling processes. This approach may allow us to explore quantum coherent interfaces between semiconducting and superconducting qubits.
Quantum physics with non-Hermitian operators Quantum physics with non-Hermitian operators
NASA Astrophysics Data System (ADS)
Bender, Carl; Fring, Andreas; Günther, Uwe; Jones, Hugh
2012-11-01
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
Wigner function approach to the quantum Brownian motion of a particle in a potential.
Coffey, W T; Kalmykov, Yu P; Titov, S V; Mulligan, B P
2007-07-14
Recent progress in our understanding of quantum effects on the Brownian motion in an external potential is reviewed. This problem is ubiquitous in physics and chemistry, particularly in the context of decay of metastable states, for example, the reversal of the magnetization of a single domain ferromagnetic particle, kinetics of a superconducting tunnelling junction, etc. Emphasis is laid on the establishment of master equations describing the diffusion process in phase space analogous to the classical Fokker-Planck equation. In particular, it is shown how Wigner's [E. P. Wigner, Phys. Rev., 1932, 40, 749] method of obtaining quantum corrections to the classical equilibrium Maxwell-Boltzmann distribution may be extended to the dissipative non-equilibrium dynamics governing the quantum Brownian motion in an external potential V(x), yielding a master equation for the Wigner distribution function W(x,p,t) in phase space (x,p). The explicit form of the master equation so obtained contains quantum correction terms up to o(h(4)) and in the classical limit, h --> 0, reduces to the classical Klein-Kramers equation. For a quantum oscillator, the method yields an evolution equation coinciding in all respects with that of Agarwal [G. S. Agarwal, Phys. Rev. A, 1971, 4, 739]. In the high dissipation limit, the master equation reduces to a semi-classical Smoluchowski equation describing non-inertial quantum diffusion in configuration space. The Wigner function formulation of quantum Brownian motion is further illustrated by finding quantum corrections to the Kramers escape rate, which, in appropriate limits, reduce to those yielded via quantum generalizations of reaction rate theory. PMID:17664961
Alpha Particle Physics Experiments in the Tokamak Fusion Test Reactor
Budny, R.V.; Darrow, D.S.; Medley, S.S.; Nazikian, R.; Zweben, S.J.; et al.
1998-12-14
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.
Quantum theory of particles of indefinite mass: Spin- 1/2
Hostler, L.
1985-10-01
The quantum theory of particles of indefinite mass investigated earlier by Hostler (J. Math. Phys. 21, 2461 (1980); 22, 2307 (1981)) is adapted to apply to spin- 1/2 particles. The proposed wave equation is ) 1/2 Pix(1+isigma)xPi+(1/i)(partial/partiallambda)) phi = 0, Pi/sub ..mu../ = p/sub ..mu../-eA/sub ..mu../, in which phi is a 2 x 1 Pauli spinor and sigma is a spin tensor whose Lorentz components are 2 x 2 Pauli spin matrices. Particle scattering by an external c-number static field is computed within the framework of the new formalism, and agreement with the known physics of a charged spin- 1/2 particle is obtained for this special case.
Annihilation physics of exotic galactic dark matter particles
NASA Technical Reports Server (NTRS)
Stecker, F. W.
1990-01-01
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.
Lagrangian Description for Particle Interpretations of Quantum Mechanics: Single-Particle Case
NASA Astrophysics Data System (ADS)
Sutherland, Roderick I.
2015-11-01
A Lagrangian description is presented which can be used in conjunction with particle interpretations of quantum mechanics. A special example of such an interpretation is the well-known Bohm model. The Lagrangian density introduced here also contains a potential for guiding the particle. The advantages of this description are that the field equations and the particle equations of motion can both be deduced from a single Lagrangian density expression and that conservation of energy and momentum are assured. After being developed in a general form, this Lagrangian formulation is then applied to the special case of the Bohm model as an example. It is thereby demonstrated that such a Lagrangian description is compatible with the predictions of quantum mechanics.
One hundred years of quantum physics.
Kleppner, D; Jackiw, R
2000-08-11
This year marks the 100th anniversary of Max Planck's creation of the quantum concept, an idea so revolutionary that it took nearly 30 years for scientists to develop it into the theory that has transformed the way scientists view reality. In this month's essay, Daniel Kleppner and Roman Jackiw recount how quantum theory, which they rate as "the most precisely tested and most successful theory in the history of science," came to be, how it changed the world, and how it might continue to evolve to make the dream of ultimate understanding of the universe come true. PMID:17839156
Pre-Service Physics Teachers' Comprehension of Quantum Mechanical Concepts
ERIC Educational Resources Information Center
Didis, Nilufer; Eryilmaz, Ali; Erkoc, Sakir
2010-01-01
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…
Making the Transition from Classical to Quantum Physics
ERIC Educational Resources Information Center
Dutt, Amit
2011-01-01
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…
Making the Transition from Classical to Quantum Physics
ERIC Educational Resources Information Center
Dutt, Amit
2011-01-01
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
Topics in quantum physics with origins in astronomy: Two examples
NASA Astrophysics Data System (ADS)
Rau, A. R. P.
2012-05-01
Astronomy has provided the inspiration for several investigations in quantum physics. These topics can serve as pedagogical vehicles for undergraduate courses in physics and astronomy. Two examples are considered, atoms in strong magnetic fields and the negative ion of hydrogen. Both are fundamental problems of quantum physics which involve basic principles and techniques and are of practical interest and historically important. They also provide, in a form accessible to undergraduates, analogs of exotic topics such as the stability at a saddle of a potential surface, supersymmetry, dimensional reduction, and models for fundamental constants.
Quantum dot solar cell tolerance to alpha-particle irradiation
Cress, Cory D.; Hubbard, Seth M.; Landi, Brian J.; Raffaelle, Ryne P.; Wilt, David M.
2007-10-29
The effects of alpha-particle irradiation on an InAs quantum dot (QD) array and GaAs-based InAs QD solar cells were investigated. Using photoluminescence (PL) mapping, the PL intensity at 872 and 1120 nm, corresponding to bulk GaAs and InAs QD emissions, respectively, were measured for a five-layer InAs QD array which had a spatially varying total alpha-particle dose. The spectral response and normalized current-voltage parameters of the solar cells, measured as a function of alpha-particle fluence, were used to investigate the change in device performance between GaAs solar cells with and without InAs QDs.
Multiple particle production processes in the light'' of quantum optics
Friedlander, E.M.
1990-09-01
Ever since the observation that high-energy nuclear active'' cosmic-ray particles create bunches of penetrating particles upon hitting targets, a controversy has raged about whether these secondaries are created in a single act'' or whether many hadrons are just the result of an intra-nuclear cascade, yielding one meson in every step. I cannot escape the impression that: the latter kind of model appeals naturally as a consequence of an innate bio-morphism in our way of thinking and that in one guise or another it has tenaciously survived to this day, also for hadron-hadron collisions, via multi-peripheral models to the modern parton shower approach. Indeed, from the very beginning of theoretical consideration of multiparticle production, the possibility of many particles arising from a single hot'' system has been explored, with many fruitful results, not the least of which are the s{sup 1/4} dependence of the mean produced particle multiplicity and the thermal'' shape of the P{sub T} spectra. An important consequence of the thermodynamical-hydrodynamical models is that particle emission is treated in analogy to black-body radiation, implying for the secondaries a set of specific Quantum-Statistical properties, very similar to those observed in quantum optics. From here on I shall try to review a number of implications and applications of this QS analogy in the study of multiplicity distributions of the produced secondaries. I will touch only in passing another very important topic of this class, the Bose-Einstein two-particle correlations.
On the justification of multiple selection rules of conservation in particle physics phenomenology
NASA Astrophysics Data System (ADS)
Valdés-Pérez, Raúl E.
1996-03-01
Earlier we analyzed the logic of postulating selection rules of conservation in particle physics phenomenology, and wrote a computer program that recovered the strangeness quantum numbers from historical reactions and assumptions. We proved the theorem that one selection rule suffices to account for any reactions data that can be explained in terms of conserved quantum numbers. Since physics practice involves multiple selection rules, this raised the issue of how to justify multiple rules in the face of this theorem. This article analyses several simplicity criteria and procedures, of which two lead to the desired justification: a minimax simplicity criterion, and a divide-and-con quer approach that leads to allowing conservation exceptions, i.e., reactions that disconserve quantum numbers that are postulated in other contexts not involving the reactions.
Simulations of two-particle interactions with 2D quantum walks in time
Schreiber, A.; Laiho, K.; Silberhorn, C.; Rohde, P. P.; Štefaňak, M.; Potoček, V.; Hamilton, C.; Jex, I.
2014-12-04
We present the experimental implementation of a quantum walk on a two-dimensional lattice and show how to employ the optical system to simulate the quantum propagation of two interacting particles. Our quantum walk in time transfers the spatial spread of a quantum walk into the time domain, which guarantees a high stability and scalability of the setup. We present with our device quantum walks over 12 steps on a 2D lattice. By changing the properties of the driving quantum coin, we investigate different kinds of two-particle interactions and reveal their impact on the occurring quantum propagation.
Macroscopic entanglement in many-particle quantum states
NASA Astrophysics Data System (ADS)
Tichy, Malte C.; Park, Chae-Yeun; Kang, Minsu; Jeong, Hyunseok; Mølmer, Klaus
2016-04-01
We elucidate the relationship between Schrödinger-cat-like macroscopicity and geometric entanglement and argue that these quantities are not interchangeable. While both properties are lost due to decoherence, we show that macroscopicity is rare in uniform and in so-called random physical ensembles of pure quantum states, despite possibly large geometric entanglement. In contrast, permutation-symmetric pure states feature rather low geometric entanglement and strong and robust macroscopicity.
Quantum dot-containing polymer particles with thermosensitive fluorescence
NASA Astrophysics Data System (ADS)
Generalova, Alla N.; Oleinikov, Vladimir A.; Sukhanova, Alyona; Artemyev, Mikhail V.; Zubov, Vitaly P.; Nabiev, Igor
2012-10-01
In the past decades, increasing attention has been paid to the preparation of "smart" functionalized polymer particles reversibly responding to slight environmental changes, such as variations in temperature, pH, and ionic strength. The 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 prepared. The thermosensitive 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 used as a shell. Embedding QDs in the PVCL shell makes it possible to obtain particles whose fluorescence is sensitive to temperature changes. The temperature-dependent fluorescence of particles was determined by reversible variation of the distances between QDs in the PVCL shell as a result of temperature-driven conformational changes in this polymer. In addition, these particles can be used as carriers of biomolecule (e.g., bovine serum albumin, BSA) characterized by reversibly temperature-dependent fluorescence, which can serve as the basis for optical detection methods in bioassays, such as the measurement of local temperature in nanovolumes, biosensing, etc.
CCDM model from quantum particle creation: constraints on dark matter mass
Jesus, J.F.; Pereira, S.H. E-mail: shpereira@gmail.com
2014-07-01
In this work the results from the quantum process of matter creation have been used in order to constrain the mass of the dark matter particles in an accelerated Cold Dark Matter model (Creation Cold Dark Matter, CCDM). In order to take into account a back reaction effect due to the particle creation phenomenon, it has been assumed a small deviation ε for the scale factor in the matter dominated era of the form t{sup 2/3+ε}. Based on recent H(z) data, the best fit values for the mass of dark matter created particles and the ε parameter have been found as m = 1.6× 10{sup 3} GeV, restricted to a 68.3% c.l. interval of 1.5 < m < 6.3× 10{sup 7}) GeV and ε = -0.250{sup +0.15}{sub -0.096} at 68.3% c.l. For these best fit values the model correctly recovers a transition from decelerated to accelerated expansion and admits a positive creation rate near the present era. Contrary to recent works in CCDM models where the creation rate was phenomenologically derived, here we have used a quantum mechanical result for the creation rate of real massive scalar particles, given a self consistent justification for the physical process. This method also indicates a possible solution to the so called ''dark degeneracy'', where one can not distinguish if it is the quantum vacuum contribution or quantum particle creation which accelerates the Universe expansion.
The Oxford Questions on the foundations of quantum physics.
Briggs, G A D; Butterfield, J N; Zeilinger, A
2013-09-01
The twentieth century saw two fundamental revolutions in physics-relativity and quantum. Daily use of these theories can numb the sense of wonder at their immense empirical success. Does their instrumental effectiveness stand on the rock of secure concepts or the sand of unresolved fundamentals? Does measuring a quantum system probe, or even create, reality or merely change belief? Must relativity and quantum theory just coexist or might we find a new theory which unifies the two? To bring such questions into sharper focus, we convened a conference on Quantum Physics and the Nature of Reality. Some issues remain as controversial as ever, but some are being nudged by theory's secret weapon of experiment. PMID:24062626
Quantum Hall physics with photons and its application
NASA Astrophysics Data System (ADS)
Hafezi, Mohammad
2012-02-01
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.
On the semiclassical approach to quantum cosmology: relational particle model
NASA Astrophysics Data System (ADS)
Anderson, Edward
2011-09-01
The emergent semiclassical time approach to resolving the problem of time in quantum gravity involves heavy slow degrees of freedom providing via an approximately Hamilton-Jacobi equation an approximate time standard with respect to which the quantum mechanics of light fast degrees of freedom can run. More concretely, this approach involves Born-Oppenheimer and WKB ansätze and some accompanying approximations. In this paper, I investigate this approach for concrete scaled relational particle mechanics models, i.e. models featuring only relative separations, relative angles and relative times. I consider the heavy-light interaction term in the light quantum equation—necessary for the semiclassical approach to work, first as an emergent-time-dependent perturbation of the emergent-time-dependent Schrödinger equation for the light subsystem. Secondly, I consider a scheme in which the backreaction is small but non-negligible, so that the l-subsystem also affects the form of the emergent time. I also suggest that the many terms involving expectation values of the light wavefunctions in both the (unapproximated) heavy and light equations might require treatment in parallel to the Hartree-Fock self-consistent approach rather than merely being discarded; for the moment this paper provides a counterexample to such terms being smaller than their unaveraged counterparts. Investigation of these ideas and methods will give us a more robust understanding of the suggested quantum-cosmological origin of microwave background inhomogeneities and galaxies.
Physical model for the generation of ideal resources in multipartite quantum networking
Ciccarello, F.; Zarcone, M.; Paternostro, M.; Bose, S.; Browne, D. E.; Palma, G. M.
2010-09-15
We propose a physical model for generating multipartite entangled states of spin-s particles that have important applications in distributed quantum information processing. Our protocol is based on a process where mobile spins induce the interaction among remote scattering centers. As such, a major advantage lies in the management of stationary and well-separated spins. Among the generable states, there is a class of N-qubit singlets allowing for optimal quantum telecloning in a scalable and controllable way. We also show how to prepare Aharonov, W, and Greenberger-Horne-Zeilinger states.
The physical principles of quantum mechanics. A critical review
NASA Astrophysics Data System (ADS)
Strocchi, F.
2012-01-01
The standard presentation of the principles of quantum mechanics is critically reviewed both from the experimental/operational point and with respect to the request of mathematical consistency and logical economy. A simpler and more physically motivated formulation is discussed. The existence of non commuting observables, which characterizes quantum mechanics with respect to classical mechanics, is related to operationally testable complementarity relations, rather than to uncertainty relations. The drawbacks of Dirac argument for canonical quantization are avoided by a more geometrical approach.
Particle physics. Positrons ride the wave
Piot, Philippe
2015-08-26
Experiments reveal that positrons — the antimatter equivalents of electrons — can be rapidly accelerated using a plasma wave. The findings pave the way to high-energy electron–positron particle colliders.
Teaching Elementary Particle Physics, Part II
NASA Astrophysics Data System (ADS)
Hobson, Art
2011-03-01
In order to explain certain features of radioactive beta decay, Wolfgang Pauli suggested in 1930 that the nucleus emitted, in addition to a beta particle, another particle of an entirely new type. The hypothesized particle, dubbed the neutrino, would not be discovered experimentally for another 25 years. It's not easy to detect neutrinos, because they respond to neither the EM force nor the strong force. For example, the mean free path (average penetration distance before it interacts) of a typical beta-decay neutrino moving through solid lead is about 1.5 light years! Enrico Fermi argued that neutrinos indicated a new force was at work. During the 1930s, he quickly adapted ideas from the developing new theory of QED to this new force, dubbed the weak force. Fermi's theory was able to predict the half-lives of beta-emitting nuclei and the range of energies of the emitted beta particles.
A Reconfigurable Instrument System for Nuclear and Particle Physics Experiments
NASA Astrophysics Data System (ADS)
Sang, Ziru; Li, Feng; Jiang, Xiao; Jin, Ge
2014-04-01
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.
Particle physics meets cosmology - The search for decaying neutrinos
NASA Technical Reports Server (NTRS)
Henry, R. C.
1982-01-01
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.
Synthesis of quantum chromodynamics and nuclear physics
Brodsky, S.J.; Lepage, G.P.
1980-08-01
The asymptotic freedom behavior of quantum chromodynamics allows the rigorous calculation of hadronic and nuclear amplitudes at short distances by perturbative methods. The implications of QCD for large-momentum-transfer nuclear form factors and scattering processes, as well as for the structure of nuclear wave functions and nuclear interactions at short distances, are discussed. The necessity for color-polarized internal nuclear states is also discussed. 6 figures.
Lattice quantum chromodynamical approach to nuclear physics
NASA Astrophysics Data System (ADS)
Aoki, Sinya; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Ishii, Noriyoshi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji; HAL QCD Collaboration
2012-09-01
We review recent progress in the HAL QCD method, which was recently proposed to investigate hadron interactions in lattice quantum chromodynamics (QCD). The strategy to extract the energy-independent non-local potential in lattice QCD is explained in detail. The method is applied to study nucleon-nucleon, nucleon-hyperon, hyperon-hyperon, and meson-baryon interactions. Several extensions of the method are also discussed.
The Bondons: The Quantum Particles of the Chemical Bond
Putz, Mihai V.
2010-01-01
By employing the combined Bohmian quantum formalism with the U(1) and SU(2) gauge transformations of the non-relativistic wave-function and the relativistic spinor, within the Schrödinger and Dirac quantum pictures of electron motions, the existence of the chemical field is revealed along the associate bondon particle B̶ characterized by its mass (mB̶), velocity (vB̶), charge (eB̶), and life-time (tB̶). This is quantized either in ground or excited states of the chemical bond in terms of reduced Planck constant ħ, the bond energy Ebond and length Xbond, respectively. The mass-velocity-charge-time quaternion properties of bondons’ particles were used in discussing various paradigmatic types of chemical bond towards assessing their covalent, multiple bonding, metallic and ionic features. The bondonic picture was completed by discussing the relativistic charge and life-time (the actual zitterbewegung) problem, i.e., showing that the bondon equals the benchmark electronic charge through moving with almost light velocity. It carries negligible, although non-zero, mass in special bonding conditions and towards observable femtosecond life-time as the bonding length increases in the nanosystems and bonding energy decreases according with the bonding length-energy relationship Ebond[kcal/mol]×Xbond[A0]=182019, providing this way the predictive framework in which the B̶ particle may be observed. Finally, its role in establishing the virtual states in Raman scattering was also established. PMID:21151435
Particle Physics Meets Cosmology -- The Search for Decaying Neutrinos.
ERIC Educational Resources Information Center
Henry, Richard C.
1982-01-01
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)
New phenomena in non-equilibrium quantum physics
NASA Astrophysics Data System (ADS)
Kitagawa, Takuya
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.
Variance of the quantum dwell time for a nonrelativistic particle
Hahne, G. E.
2013-01-15
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.
Variance of the quantum dwell time for a nonrelativistic particle
NASA Astrophysics Data System (ADS)
Hahne, G. E.
2013-01-01
Muñoz, Seidel, and Muga [Phys. Rev. A 79, 012108 (2009), 10.1103/PhysRevA.79.012108], following an earlier proposal by Pollak and Miller [Phys. Rev. Lett. 53, 115 (1984), 10.1103/PhysRevLett.53.115] 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), 10.1088/0305-4470/36/25/316]; 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.
Weak cosmic censorship, superradiance, and quantum particle creation
NASA Astrophysics Data System (ADS)
Semiz, Ibrahim; Düztaş, Koray
2015-11-01
Starting in 2007, a string of papers argue about if the weak cosmic censorship conjecture (WCCC) can be violated by classically forbidden interactions between particles and slightly subextremal black holes, occurring via the quantum nature of the particles; and where backreaction and/or superradiance are pointed out as effects working in the direction of preserving the WCCC. We correct/modify a backreaction argument, point out that transmission/reflection coefficients for relativistic wave equations are not the respective probabilities, and conclude that superradiance does not prevent single particles from being captured by the black hole; even if this capture would lead to WCCC violation. Then we consider the spontaneous emission (which we call the Zel'dovich-Unruh "ZU" effect) of particles by the black hole, and point out that it completely invalidates the mentioned single- or few-particle thought experiments. We find that at least for scalars, the ZU effect can be understood without second quantization; and reevaluate our previous work on scalar fields interacting with black holes in view of this new understanding, finding that it becomes inconclusive.
Quantum Mechanics for Beginning Physics Students
ERIC Educational Resources Information Center
Schneider, Mark B.
2010-01-01
The past two decades of attention to introductory physics education has emphasized enhanced development of conceptual understanding to accompany calculational ability. Given this, it is surprising that current texts continue to rely on the Bohr model to develop a flawed intuition, and introduce correct atomic physics on an ad hoc basis. For…
Quantum Mechanics for Beginning Physics Students
ERIC Educational Resources Information Center
Schneider, Mark B.
2010-01-01
The past two decades of attention to introductory physics education has emphasized enhanced development of conceptual understanding to accompany calculational ability. Given this, it is surprising that current texts continue to rely on the Bohr model to develop a flawed intuition, and introduce correct atomic physics on an ad hoc basis. For
The Qubit as Key to Quantum Physics Part II: Physical Realizations and Applications
NASA Astrophysics Data System (ADS)
Dür, Wolfgang; Heusler, Stefan
2016-03-01
Using the simplest possible quantum system—the qubit—the fundamental concepts of quantum physics can be introduced. This highlights the common features of many different physical systems, and provides a unifying framework when teaching quantum physics at the high school or introductory level. In a previous TPT article and in a separate paper posted online, we introduced catchy visualizations of the qubit based on the Bloch sphere or just the unit circle (see also Refs. 3-8 for other approaches highlighting the importance of the qubit). These visualizations open the way to understand basic ideas of quantum physics even without knowledge of the underlying mathematical formalism. In addition, simple mathematics can be introduced to describe the qubit as an abstract object and basic unit of quantum information. This generalizes the digital bit as a basic unit of classical information. The proposed visualizations can be used even at the high school level, while the mathematical explanations are of importance when teaching quantum physics at the undergraduate university level. This approach provides a unified framework to introduce common features of all quantum systems, such as the stochastic behavior and state change of a superposition state under measurement.
Time evolution of decay of two identical quantum particles
Garcia-Calderon, Gaston; Mendoza-Luna, Luis Guillermo
2011-09-15
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.
(Participation in high energy physics): Task C, Particle physics and cosmology
Turner, M.S.
1992-05-01
Over the past year or so the research of our group has spanned many topics at the boundary of particle physics and cosmology. The major focus has been in the general areas of inflation, cosmological phase transitions, astrophysical constraints to particle physics theories, and dark matter/structure formation as it relates to particle physics. Narrative summaries of the research of the individual group members are given in this paper.
Schipper, Meike L.; Iyer, Gopal; Koh, Ai Leen; Cheng, Zhen; Ebenstein, Yuval; Aharoni, Assaf; Keren, Shay; Bentolila, Laurent A.; Li, Jianquing; Rao, Jianghong; Chen, Xiaoyuan; Banin, Uri; Wu, Anna M.; Sinclair, Robert; Weiss, Shimon
2011-01-01
This study evaluates the influence of particle size, PEGylation, and surface coating on the quantitative biodistribution of near-infrared-emitting quantum dots (QDs) in mice. Polymer- or peptide-coated 64Cu-labeled QDs 2 or 12 nm in diameter, with or without polyethylene glycol (PEG) of molecular weight 2000, are studied by serial micropositron emission tomography imaging and region-of-interest analysis, as well as transmission electron microscopy and inductively coupled plasma mass spectrometry. PEGylation and peptide coating slow QD uptake into the organs of the reticuloendothelial system (RES), liver and spleen, by a factor of 69 and 23, respectively. Small particles are in part renally excreted. Peptide-coated particles are cleared from liver faster than physical decay alone would suggest. Renal excretion of small QDs and slowing of RES clearance by PEGylation or peptide surface coating are encouraging steps toward the use of modified QDs for imaging living subjects. PMID:19051182
The geometric phase in quantum physics
Bohm, A.
1993-03-01
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.
Quantum gravity influences the black hole physics
NASA Astrophysics Data System (ADS)
Li, Xiang
2002-06-01
The new state equations of thermal radiation is obtained by using the generalized uncertainty relation, in the context of quantum gravity. It is noticeable that the pressure of radiation becomes divergent when the system approaches a non-zero minimal length, which implies the prohibition against the singularity in the formation of black hole. Using the time-energy uncertainty, the corrections to the Schwarzchild black hole thermodynamics are investigated. A negative and logarithmic correction to the Bekenstein-Hawking entropy is obtained. The mass loss rate of the black hole in the Planck realm is also discussed.
Effective theories and thresholds in particle physics
Gaillard, M.K.
1991-06-07
The role of effective theories in probing a more fundamental underlying theory and in indicating new physics thresholds is discussed, with examples from the standard model and more speculative applications to superstring theory. 38 refs.
Elementary particle physics and high energy phenomena
Barker, A.R.; Cumalat, J.P.; de Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.
1992-06-01
This report discusses the following research in high energy physics: the properties of the z neutral boson with the SLD detector; the research and development program for the SDC muon detector; the fixed-target k-decay experiments; the Rocky Mountain Consortium for HEP; high energy photoproduction of states containing heavy quarks; and electron-positron physics with the CLEO II and Mark II detectors. (LSP).
American particle and nuclear physics planning
Montgomery, Hugh E.
2014-10-01
In the United States the planning process relevant to future deep inelastic scattering involves both the high energy physics and nuclear physics funding and the two communities. In Canada there is no such split between the communities. Within the past two years there have been several planning initiatives and there may be more to come. We review the current status of both the planning and the plans.
MEASUREMENTS OF BLACK CARBON PARTICLES CHEMICAL, PHYSICAL, AND OPTICAL PROPERTIES
Onasch, T.B.; Sedlacek, A.; Cross, E. S.; Davidovits, P.; Worsnop, D. R.; Ahern, A.; Lack, D. A.; Cappa, C. D.; Trimborn, A.; Freedman, A.; Olfert, J. S.; Jayne, J. T.; Massoli, P.; Williams, L. R.; Mazzoleni, C.; Schwarz, J. P.; Thornhill, D. A.; Slowik, J. G.; Kok, G. L.; Brem, B. T.; Subramanian, R.; Spackman, J. R.; Freitag, S.; and Dubey, M. K.
2009-12-14
Accurate measurements of the chemical, physical, and optical properties of aerosol particles containing black carbon are necessary to improve current estimates of the radiative forcing in the atmosphere. A collaborative research effort between Aerodyne Research, Inc. and Boston College has focused on conducting field and laboratory experiments on carbonaceous particles and the development and characterization of new particulate instrumentation. This presentation will focus on the chemical, physical, and optical properties of black carbon particles measured in the laboratory in order to understand the effects of atmospheric processing on black carbon particles. Results from a three-week study during July 2008 of mass- and optical-based black carbon measurements will be presented. The project utilized the Boston College laboratory flame apparatus and aerosol conditioning and characterization equipment. A pre-mixed flat flame burner operating at controlled fuel-to-air ratios produced stable and reproducible concentrations of soot particles with known sizes, morphologies, and chemical compositions. In addition, other black carbon particle types, including fullerene soot, glassy carbon spheres, oxidized flame soot, Regal black, and Aquadag, were also atomized, size selected, and sampled. The study covered an experimental matrix that systematically selected particle mobility size (30 to 300 nm) and black carbon particle mass, particle number concentration, particle shape (dynamic shape factor and fractal dimension), and particle chemistry and density (changed via coatings). Particles were coated with a measured thickness (few nm to {approx}150 nm) of sulfuric acid or bis (2-ethylhexyl) sebacate and passed through a thermal denuder to remove the coatings. Highlights of the study to be presented include: (1) Characterization of the chemical and physical properties of various types of black carbon particles, (2) Mass specific absorption measurements as a function of fuel-to-air ratio and carbon particle type, (3) Optical absorption nhancement measurements as a function of coatings, and (4) Particle shape determination as a function of fuel-to-air ratio and collapse observed due to coatings.
Celebrating 40 years of research in Journal of Physics G: Nuclear and Particle Physics
NASA Astrophysics Data System (ADS)
Adcock, Colin D.; Martin, Alan D.; Schwenk, Achim
2015-09-01
2015 marks the 40th anniversary of Journal of Physics G: Nuclear and Particle Physics. This editorial provides a brief history of the journal, and introduces a unique collection of invited articles from leading authors to celebrate the occasion.
Hands on CERN - An Internet Educational Project in Particle Physics
NASA Astrophysics Data System (ADS)
Johansson, K. E.
With the Hands on CERN project it is possible to ``take part'' in a modern particle physics experiment at the forefront of scientific research using scientific data transmitted via Internet. The primary aim is to show particle collisions from the physics frontline, to stimulate the interest in science and technology and to demonstrate the openness and international character of fundamental research. Hands on CERN complements the traditional physics education and confronts the students with contemporary physics and technology - both detector technology and data transmission technology via Internet - at its most fundamental level.
Quantum Processes and Dynamic Networks in Physical and Biological Systems.
NASA Astrophysics Data System (ADS)
Dudziak, Martin Joseph
Quantum theory since its earliest formulations in the Copenhagen Interpretation has been difficult to integrate with general relativity and with classical Newtonian physics. There has been traditionally a regard for quantum phenomena as being a limiting case for a natural order that is fundamentally classical except for microscopic extrema where quantum mechanics must be applied, more as a mathematical reconciliation rather than as a description and explanation. Macroscopic sciences including the study of biological neural networks, cellular energy transports and the broad field of non-linear and chaotic systems point to a quantum dimension extending across all scales of measurement and encompassing all of Nature as a fundamentally quantum universe. Theory and observation lead to a number of hypotheses all of which point to dynamic, evolving networks of fundamental or elementary processes as the underlying logico-physical structure (manifestation) in Nature and a strongly quantized dimension to macroscalar processes such as are found in biological, ecological and social systems. The fundamental thesis advanced and presented herein is that quantum phenomena may be the direct consequence of a universe built not from objects and substance but from interacting, interdependent processes collectively operating as sets and networks, giving rise to systems that on microcosmic or macroscopic scales function wholistically and organically, exhibiting non-locality and other non -classical phenomena. The argument is made that such effects as non-locality are not aberrations or departures from the norm but ordinary consequences of the process-network dynamics of Nature. Quantum processes are taken to be the fundamental action-events within Nature; rather than being the exception quantum theory is the rule. The argument is also presented that the study of quantum physics could benefit from the study of selective higher-scale complex systems, such as neural processes in the brain, by virtue of mathematical and computational models that may be transferred from the macroscopic domain to the microscopic. A consequence of this multi-faceted thesis is that there may be mature analytical tools and techniques that have heretofore not been adequately recognized for their value to quantum physics. These may include adaptations of neural networks, cellular automata, chaotic attractors, and parallel processing systems. Conceptual and practical architectures are presented for the development of software and hardware environments to employ massively parallel computing for the modeling of large populations of dynamic processes.
Quantum particle statistics on the holographic screen leads to modified Newtonian dynamics
NASA Astrophysics Data System (ADS)
Pazy, E.; Argaman, N.
2012-05-01
Employing a thermodynamic interpretation of gravity based on the holographic principle and assuming underlying particle statistics, fermionic or bosonic, for the excitations of the holographic screen leads to modified Newtonian dynamics (MOND). A connection between the acceleration scale a0 appearing in MOND and the Fermi energy of the holographic fermionic degrees of freedom is obtained. In this formulation the physics of MOND results from the quantum-classical crossover in the fermionic specific heat. However, due to the dimensionality of the screen, the formalism is general and applies to two-dimensional bosonic excitations as well. It is shown that replacing the assumption of the equipartition of energy on the holographic screen by a standard quantum-statistical-mechanics description wherein some of the degrees of freedom are frozen out at low temperatures is the physical basis for the MOND interpolating function μ˜. The interpolating function μ˜ is calculated within the statistical mechanical formalism and compared to the leading phenomenological interpolating functions, most commonly used. Based on the statistical mechanical view of MOND, its cosmological implications are reinterpreted: the connection between a0 and the Hubble constant is described as a quantum uncertainty relation; and the relationship between a0 and the cosmological constant is better understood physically.
The future of particle physics in the Far East
NASA Astrophysics Data System (ADS)
Nakamura, K.
1998-07-01
The future projects in experimental particle physics in Japan, China, Korea, and Taiwan are reported. In addition, the activity of Asian Committee for Future Accelerators (ACFA) and the recent reorganization of KEK are briefly described.
The role of supersymmetry phenomenology in particle physics
Wells, James D.
2000-12-14
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.
Research program in particle physics. Progress report, January 1, 1992--December 1992
Sudarshan, E.C.G.; Dicus, D.A.; Ritchie, J.L.; Lang, K.
1992-07-01
This report discusses the following topics: Quantum Gravity and Mathematical Physics; Phenomenology; Quantum Mechanics and Quantum Field Theory; Status of BNL Expt. 791; BNL Expt. 791; BNL Expt. 888; and SSC Activities.
Mapping of topological quantum circuits to physical hardware.
Paler, Alexandru; Devitt, Simon J; Nemoto, Kae; Polian, Ilia
2014-01-01
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
The Oxford Questions on the foundations of quantum physics
Briggs, G. A. D.; Butterfield, J. N.; Zeilinger, A.
2013-01-01
The twentieth century saw two fundamental revolutions in physics—relativity and quantum. Daily use of these theories can numb the sense of wonder at their immense empirical success. Does their instrumental effectiveness stand on the rock of secure concepts or the sand of unresolved fundamentals? Does measuring a quantum system probe, or even create, reality or merely change belief? Must relativity and quantum theory just coexist or might we find a new theory which unifies the two? To bring such questions into sharper focus, we convened a conference on Quantum Physics and the Nature of Reality. Some issues remain as controversial as ever, but some are being nudged by theory's secret weapon of experiment. PMID:24062626
Physics of compaction of fine cohesive particles.
Castellanos, A; Valverde, J M; Quintanilla, M A S
2005-02-25
Fluidized fractal clusters of fine particles display critical-like dynamics at the jamming transition, characterized by a power law relating consolidation stress with volume fraction increment [sigma--(c) proportional, variant(Deltaphi)(beta)]. At a critical stress clusters are disrupted and there is a crossover to a logarithmic law (Deltaphi = nu logsigma--(c)) resembling the phenomenology of soils. We measure lambda identical with- partial differentialDelta(1/phi)/ partial log(sigma--(c) proportional, variant Bo(0.2)(g), where Bo(g) is the ratio of interparticle attractive force (in the fluidlike regime) to particle weight. This law suggests that compaction is ruled by the internal packing structure of the jammed clusters at nearly zero consolidation. PMID:15783824
Improvements on "multiparty quantum key agreement with single particles"
NASA Astrophysics Data System (ADS)
Sun, Zhiwei; Zhang, Cai; Wang, Banghai; Li, Qin; Long, Dongyang
2013-11-01
Recently, Liu et al. (Quantum Inf Process 12: 1797-1805, 2013) proposed a secure multiparty quantum key agreement (MQKA) protocol with single particles. Their protocol allows N parties to negotiate a secret session key in such away that (1) outside eavesdroppers cannot gain the session key without introducing any errors; (2) the session key cannot be determined by any non-trivial subset of the participants. However, the particle efficiency of their protocol is only . In this paper, we show that the efficiency of the MQKA protocol can be improved to by introducing two additional unitary operations. Since, in some scenarios, the secret keys are confidential, neither party is willing to divulge any of the contents to the other. Therefore, in our protocol, no participant can learn anything more than its prescribed output, i.e., the secret keys of the participants can be kept secret during the protocol instead of being exposed to others, thus, the privacy of the protocol is also improved. Furthermore, we explicitly show the scheme is secure.
NASA Astrophysics Data System (ADS)
Baily, Charles; Finkelstein, Noah D.
2015-12-01
[This paper is part of the Focused Collection on Upper Division Physics Courses.] Most introductory quantum physics instructors would agree that transitioning students from classical to quantum thinking is an important learning goal, but may disagree on whether or how this can be accomplished. Although (and perhaps because) physicists have long debated the physical interpretation of quantum theory, many instructors choose to avoid emphasizing interpretive themes; or they discuss the views of scientists in their classrooms, but do not adequately attend to student interpretations. In this synthesis and extension of prior work, we demonstrate the following: (i) instructors vary in their approaches to teaching interpretive themes; (ii) different instructional approaches have differential impacts on student thinking; and (iii) when student interpretations go unattended, they often develop their own (sometimes scientifically undesirable) views. We introduce here a new modern physics curriculum that explicitly attends to student interpretations, and provide evidence-based arguments that doing so helps them to develop more consistent interpretations of quantum phenomena, more sophisticated views of uncertainty, and greater interest in quantum physics.
Kolovsky, A.R.
1997-08-01
We study the spectral properties of the evolution operator of a quantum particle subject to a space-periodic time-dependent potential. Two qualitatively different regimes of the system dynamics are compared: case (i), when the spreading of the wave packet is asymptotically ballistic; and case (ii), when the wave packet spreads diffusively. As time increases, the spectrum is shown to approach Poisson statistics in case (i) and circular unitary ensemble statistics in case (ii). A scaling relation for the velocity and curvature distributions of the spectral bands are found. {copyright} {ital 1997} {ital The American Physical Society}
Two-dimensional Coulomb scattering of a quantum particle: Construction of radial wave functions
NASA Astrophysics Data System (ADS)
Pupyshev, V. V.
2016-01-01
We prove that radial wave functions of a charged quantum particle moving in a two-dimensional plane of the three-dimensional coordinate space and scattering by a Coulomb center at rest in the same plane are governed by the Coulomb equation with a half-integer index. We investigate the structure of these functions and consider three physically interesting limits: the non-Coulomb limit and high- and low-energy limits. We explicate the basic differences between two- and three-dimensional Coulomb scattering.
Energetic particle physics with applications in fusion and space plasmas
Cheng, C.Z.
1997-05-01
Energetic particle physics is the study of the effects of energetic particles on collective electromagnetic (EM) instabilities and energetic particle transport in plasmas. Anomalously large energetic particle transport is often caused by low frequency MHD instabilities, which are driven by these energetic particles in the presence of a much denser background of thermal particles. The theory of collective energetic particle phenomena studies complex wave-particle interactions in which particle kinetic physics involving small spatial and fast temporal scales can strongly affect the MHD structure and long-time behavior of plasmas. The difficulty of modeling kinetic-MHD multiscale coupling processes stems from the disparate scales which are traditionally analyzed separately: the macroscale MHD phenomena are studied using the fluid MHD framework, while microscale kinetic phenomena are best described by complicated kinetic theories. The authors have developed a kinetic-MHD model that properly incorporates major particle kinetic effects into the MHD fluid description. For tokamak plasmas a nonvariational kinetic-MHD stability code, the NOVA-K code, has been successfully developed and applied to study problems such as the excitation of fishbone and Toroidal Alfven Eigenmodes (TAE) and the sawtooth stabilization by energetic ions in tokamaks. In space plasmas the authors have employed the kinetic-MHD model to study the energetic particle effects on the ballooning-mirror instability which explains the multisatellite observation of the stability and field-aligned structure of compressional Pc 5 waves in the magnetospheric ring current plasma.
(Physics and chemistry of van der Waals particles)
Klots, C.E.
1990-10-08
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.
Future particle-physics projects in the United States
Denisov, D. S.
2015-08-25
Basic proposals of experiments aimed at precision measurements of Standard Model parameters and at searches for new particles, including dark-matter particles, are described along with future experimental projects considered by American Physical Society at the meeting in the summer of 2013 and intended for implementation within the next ten to twenty years.
Teaching Particle Physics in the Open University's Science Foundation Course.
ERIC Educational Resources Information Center
Farmelo, Graham
1992-01-01
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
Future particle-physics projects in the United States
Denisov, D. S.
2015-07-15
Basic proposals of experiments aimed at precision measurements of Standard Model parameters and at searches for new particles, including dark-matter particles, are described along with future experimental projects considered by American Physical Society at the meeting in the summer of 2013 and intended for implementation within the next ten to twenty years.
Teaching Particle Physics in the Open University's Science Foundation Course.
ERIC Educational Resources Information Center
Farmelo, Graham
1992-01-01
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…
Quarks, Leptons, and Bosons: A Particle Physics Primer.
ERIC Educational Resources Information Center
Wagoner, Robert; Goldsmith, Donald
1983-01-01
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)
Future particle-physics projects in the United States
NASA Astrophysics Data System (ADS)
Denisov, D. S.
2015-07-01
Basic proposals of experiments aimed at precision measurements of Standard Model parameters and at searches for new particles, including dark-matter particles, are described along with future experimental projects considered by American Physical Society at the meeting in the summer of 2013 and intended for implementation within the next ten to twenty years.
How Many Fundamental Constants Does Quantum Physics Need?
NASA Astrophysics Data System (ADS)
Wignall, J. W. G.
Of the four familiar constants c, {¯ m}e, {¯ e} and ħ (expressed in SI or other ``ordinary'' units) used in quantum mechanics and quantum electrodynamics, only three are independent because {¯ m}e, {¯ e} and ħ occur in quantum equations and their predictions only as the ratios ({¯ m}e/{ℎ }) and ({¯ e}/{√ ℎ }). If one defines the inertial mass of any particle absolutely and operationally as its rest frame de Broglie frequency, the constant quantity m≡ c2/(λ -- γ v), where λ -- is its measured de Broglie wavelength when it has speed v and Lorentz factor γ, then electric charge becomes dimensionless and ħ disappears from all quantum expressions; classical and quantum equations can then be written in terms of only three fundamental constants - c, the frequency me and the dimensionless e - and involve only two base units, those of length and time. This suggests that quantization rules, whose ``scale'' is given by ħ, can also be eliminated from the theoretical framework and that it is therefore possible to construct a single unified theory of classical and quantum phenomena.
Elementary Particle Physics at Baylor (Final Report)
Dittmann, J.R.
2012-08-25
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.
Resource Letter HEPP-1: History of elementary-particle physics
Hovis, R.C. ); Kragh, H. )
1991-09-01
This Resource Letter provides a guide to literature on the history of modern elementary-particle physics. Histories that treat developments from the 1930s through the 1980s are focused on and a sampling is included of the historiography covering the period c. 1890--1930, the prehistory of elementary-particle physics as a discipline. Also included are collections of scientific papers, which might be especially valuable to individuals who wish to undertake historical research on particular scientists or subfields of elementary-particle physics. The introduction presents some statistical data and associated references for elementary-particle physics and surveys historiographical approaches and issues that are represented in historical accounts in the bibliography. All references are assigned a rating of E (Elementary), I (Intermediate), or A (Advanced) based on their technical or conceptual difficulty or their appropriateness for a person attempting a graduated study of the history of modern particle physics. That is, items labeled E are suitable for the layman or would be fundamental to a beginning exploration of the history of particle physics, whereas items labeled A are technically demanding (mathematically, historiographically, or philosophically) or would be most appropriate for specialized or advanced examinations of various topics.
A Quantum Chemistry Concept Inventory for Physical Chemistry Classes
ERIC Educational Resources Information Center
Dick-Perez, Marilu; Luxford, Cynthia J.; Windus, Theresa L.; Holme, Thomas
2016-01-01
A 14-item, multiple-choice diagnostic assessment tool, the quantum chemistry concept inventory or QCCI, is presented. Items were developed based on published student misconceptions and content coverage and then piloted and used in advanced physical chemistry undergraduate courses. In addition to the instrument itself, data from both a pretest,…
Quantum Physics and Mental Health Counseling: The Time Is...!
ERIC Educational Resources Information Center
Gerstein, Lawrence H.; Bennett, Matt
1999-01-01
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…
Quantum Physics and Mental Health Counseling: The Time Is...!
ERIC Educational Resources Information Center
Gerstein, Lawrence H.; Bennett, Matt
1999-01-01
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
Subbarrier Fusion Reactions and Many-Particle Quantum Tunneling
NASA Astrophysics Data System (ADS)
Hagino, K.; Takigawa, N.
2012-12-01
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.
Experimental and theoretical particle physics. Final report
1996-07-09
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.
Andreev, P. A.; Kuzmenkov, L. S.; Trukhanova, M. I.
2011-12-15
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 Schroedinger equation. Fundamental QHD equations for charged and neutral particles were derived from the many-particle microscopic Schroedinger 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.
ERIC Educational Resources Information Center
Bao, Lei; Redish, Edward F.
2002-01-01
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)
Path-integral approach to 't Hooft's derivation of quantum physics from classical physics
Blasone, Massimo; Jizba, Petr; Kleinert, Hagen
2005-05-15
We present a path-integral formulation of 't Hooft's derivation of quantum physics from classical physics. The crucial ingredient of this formulation is Gozzi et al.'s supersymmetric path integral of classical mechanics. We quantize explicitly two simple classical systems: the planar mathematical pendulum and the Roessler dynamical system.
NASA Astrophysics Data System (ADS)
van Dijk, W.; Kiers, K. A.; Nogami, Y.; Platt, A.; Spyksma, K.
2003-05-01
We examine the validity of the approximation in which an alpha particle interacting with an atom is treated classically. In order to analyse such interactions, we perform a model simulation in which the alpha particle is considered as a particle in one dimension, and the atom as a quantum two-level system. The particle impinges on and excites the two-level system. We treat the particle in two ways: as a quantum mechanical wave packet, and as a classical particle. The classical particle may be a point or may have an extended structure. In each case we calculate the excitation probability P21(t) as a function of time t. We focus on the situation in which the kinetic energy of the incident particle well exceeds the excitation energy of the two-level system. Although the finite-time behaviour of P21(t) varies, P21(infty) is remarkably insensitive to the size and shape of the incident wave packet in the quantum mechanical treatment. In the classical treatment, in contrast, we find that P21(infty) is sensitive to the size of the particle. The classical point particle, however, yields nearly the same values of P21(infty) as the quantum wave packet. Implications of the results on the interaction between an alpha particle and an atom are discussed.
Santa Cruz Institute for Particle Physics (SCIPP)
Burchat, P.; Dorfan, D.; Litke, A.; Heusch, C.; Sadrozinski, H.; Schalk, T.; Seiden, A.
1992-11-01
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.
Santa Cruz Institute for Particle Physics (SCIPP)
Burchat, P.; Dorfan, D.; Litke, A.; Heusch, C.; Sadrozinski, H.; Schalk, T.; Seiden, A.
1992-01-01
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.
String Theory, the Crisis in Particle Physics and the Ascent of Metaphoric Arguments
NASA Astrophysics Data System (ADS)
Schroer, Bert
This essay presents a critical evaluation of the concepts of string theory and its impact on particle physics. The point of departure is a historical review of four decades of string theory within the broader context of six decades of failed attempts at an autonomous S matrix approach to particle theory. The central message, contained in Secs. 5 and 6, is that string theory is not what its name suggests, namely a theory of objects in space-time whose localization is string-instead of pointlike. Contrary to popular opinion, the oscillators corresponding to the Fourier models of a quantum-mechanical string do not become embedded in space-time and neither does the "range space" of a chiral conformal QFT acquire the interpretation of stringlike-localized quantum matter. Rather, string theory represents a solution to a problem which enjoyed some popularity in the 1960s: find a principle which, similar to the SO(4,2) group in the case of the hydrogen spectrum, determines an infinite component wave function with a (realistic) mass/spin spectrum. Instead of the group theory used in the old failed attempts, it creates this mass/spin spectrum by combining an internal oscillator quantum mechanics with a pointlike-localized quantum-field-theoretic object, i.e. the mass/spin tower "sits" over one point and does not arise from a wiggling string in space-time. The widespread acceptance of a theory whose interpretation has been based on metaphoric reasoning had a corroding influence on particle theory, a point which will be illustrated in the last section with some remarks of a more sociological nature. These remarks also lend additional support to observations on connections between the discourse in particle physics and the present Zeitgeist of the post-Cold War period that are made in the introduction.
Structural physical approximations of unphysical maps and generalized quantum measurements
Fiurasek, Jaromir
2002-11-01
We investigate properties of the structural physical approximation (SPA) of the partial transposition map recently introduced by Horodecki and Ekert [Phys. Rev. Lett. 89, 127902 (2002)]. We focus on the case of two-qubit states and show that in this case the map has the structure of a generalized quantum measurement followed by the preparation of a suitable output state. We also introduce SPA for a map that transforms two copies of density matrix of a single qubit onto a square of that matrix. We prove that also this map is essentially a generalized quantum measurement.
Large numbers hypothesis. IV - The cosmological constant and quantum physics
NASA Technical Reports Server (NTRS)
Adams, P. J.
1983-01-01
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.
The Groenewold-Moyal Plane and its Quantum Physics
Balachandran, A. P.; Padmanabhan, Pramod
2009-12-15
Quantum theories constructed on the noncommutative spacetime called the Groenewold-Moyal(GM) plane exhibit many interesting properties such as causality violation, Lorentz and CPT non-invariance and twisted statistics. Such violations lead to many striking features that may be tested experimentally. Thus these theories predict Pauli-forbidden transitions due to twisted statistics, anisotropies and acausal effects in the cosmic microwave background radiation in correlations of observables and Lorentz and CPT violations in scattering amplitudes. Such features of quantum physics on the GM plane are surveyed in this review.
Physical theories, eternal inflation, and the quantum universe
NASA Astrophysics Data System (ADS)
Nomura, Yasunori
2011-11-01
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.
Quantum Dots in a Polymer Composite: A Convenient Particle-in-a-Box Laboratory Experiment
ERIC Educational Resources Information Center
Rice, Charles V.; Giffin, Guinevere A.
2008-01-01
Semiconductor quantum dots are at the forefront of materials science chemistry with applications in biological imaging and photovoltaic technologies. We have developed a simple laboratory experiment to measure the quantum-dot size from fluorescence spectra. A major roadblock of quantum-dot based exercises is the particle synthesis and handling;
Quantum Dots in a Polymer Composite: A Convenient Particle-in-a-Box Laboratory Experiment
ERIC Educational Resources Information Center
Rice, Charles V.; Giffin, Guinevere A.
2008-01-01
Semiconductor quantum dots are at the forefront of materials science chemistry with applications in biological imaging and photovoltaic technologies. We have developed a simple laboratory experiment to measure the quantum-dot size from fluorescence spectra. A major roadblock of quantum-dot based exercises is the particle synthesis and handling;…
Gas-Solid Transition of Quantum Particles Interacting with Inverse-Power-Law Repulsive Potential
NASA Astrophysics Data System (ADS)
Yamashita, Kohei; Kwon, Yongkyung; Koike, Yukio; Hirashima, Dai S.
2014-04-01
We study the gas-solid phase diagram of quantum particles interacting with the inverse-power-law repulsive interaction. It is found that the solid phase is promoted by the quantum effect in the intermediate region where the quantum effect is not yet dominant but is nonnegligible. We further find that a weak minimum in the coexistence pressure curve appears at low temperatures.
Finite-particle-number approach to physics
Noyes, H.P.
1982-10-01
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.
Particle-physics constraints on multifractal spacetimes
NASA Astrophysics Data System (ADS)
Calcagni, Gianluca; Nardelli, Giuseppe; Rodríguez-Fernández, David
2016-01-01
We study electroweak interactions in the multiscale theory with q -derivatives, a framework where spacetime has the typical features of a multifractal. In the simplest case with only one characteristic time, length, and energy scale t* , ℓ* , and E* , we consider (i) the muon decay rate and (ii) the Lamb shift in the hydrogen atom, and constrain the corrections to the ordinary results. We obtain the independent absolute upper bounds (i) t*<1 0-13 s and (ii) E*>35 MeV . Under some mild theoretical assumptions, the Lamb shift alone yields the even tighter ranges t*<1 0-27 s , ℓ*<1 0-19 m , and E*>450 GeV . To date, these are the first robust constraints on the scales at which the multifractal features of the geometry can become important in a physical process.
Ionic conductivity in a quantum lattice gas model with three-particle interactions
NASA Astrophysics Data System (ADS)
Barry, J. H.; Muttalib, K. A.; Tanaka, T.
2012-12-01
A system of mesoscopic ions with dominant three-particle interactions is modeled by a quantum lattice liquid on the planar kagomé lattice. The two-parameter Hamiltonian contains localized attractive triplet interactions as potential energy and nearest neighbor hopping-type terms as kinetic energy. The dynamic ionic conductivity σ(ω) is theoretically investigated for ‘weak hopping’ via a quantum many-body perturbation expansion of the thermal (Matsubara) Green function (current-current correlation). A simple analytic continuation and mapping of the thermal Green function provide the temporal Fourier transform of the physical retarded Green function in the Kubo formula. Substituting pertinent exact solutions for static multi-particle correlations known from previous work, Arrhenius relations are revealed in zeroth-order approximation for the dc ionic conductivity σdc along special trajectories in density-temperature space. The Arrhenius plots directly yield static activation energies along the latter loci. Experimental possibilities relating to σdc are discussed in the presence of equilibrium aggregation. This article is part of ‘Lattice models and integrability’, a special issue of Journal of Physics A: Mathematical and Theoretical in honour of F Y Wu's 80th birthday.
Cosmic rays and the birth of particle physics
NASA Astrophysics Data System (ADS)
Friedlander, Michael
2013-02-01
Twenty years after the discovery of cosmic rays, the methods of research and resulting discoveries were dramatically changed by the introduction of experimental methods that made visible the passage of individual particles. Between 1932 and 1955, tracks of cosmic rays were found in cloud chambers and special photographic emulsions. From measurements of the ionization produced along these tracks, the mass, charge and energy of a single relativistic particle could be determined. The dynamics of decays and collisions could be analyzed. Positrons and then electron-positron pairs were discovered, followed by muons and pions and then the inhabitants of the 'particle zoo'. Fundamental concepts were challenged. From the mid- 1950s, larger accelerators began to produce many of the 'new' particles, displacing cosmic rays from their prime role in particle studies. But without the initial discoveries in cosmic rays, there might well not be the modern industrial-scale particle physics research.
Elementary particle physics at the University of Florida. Annual progress report
Not Available
1991-12-01
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).
The Art and Science of Experimentation in Quantum Physics
NASA Astrophysics Data System (ADS)
Plotnitsky, Arkady
2010-05-01
Taking its historical point of departure in Heisenberg's work, this article offers a view of quantum mechanics as, arguably, the first truly experimental and truly mathematical physical theory, that is, a theory concerned with experimenting with nature and mathematics alike. It is truly experimental because it is not, as in classical physics, merely the independent behavior of the system considered, in other words, what happens in any event, that we track, but what kind of experiments we perform that defines what happens. By the same token, the theory is also truly mathematical because, at least in the interpretation adopted here, its mathematical formalism does not stand in the service of a mathematical description of (quantum) physical processes in space and time in the way the formalism of classical physics does, but is only used to predict the outcomes of relevant experiments. It also follows that quantum theories experiment more freely with mathematics itself, since we invent predictive mathematical schemes, rather than proceed by refining mathematically our phenomenal representations of nature, which process constrains us in classical mechanics.
Research accomplishments and future goals in particle physics
Not Available
1991-12-01
This report presents the research accomplishments and ongoing activities of Boston University researchers in high energy physics. We are active in eight principal areas which are discussed in this report: Colliding Beams - physics of electron-positron annihilation; Accelerator Design Physics - advanced accelerator design; Monopole/ Neutrino - searchers for magnetic monopoles and for neutrino oscillations; Proton Decay - search for nucleon instability and study of nonaccelarator physics; Particle Theory - theoretical high energy particles physics; Muon G-2 - an experiment to measure the anomalous magnetic moment of the muon with a factor of 20 better precision than currently achieved; SSSintcal - scintillating fiber calorimetry for the SSC; and SSC Muon Detectors - development of muon detectors for the GEM Experiment at the SSC.
Overview of high energy physics with polarized particles
Soffer, J. . Centre de Physique Theorique Brookhaven National Lab., Upton, NY )
1990-08-01
The purpose of this talk is to review spin effects in various areas of particle physics at high energy and by selecting the most interesting topics, to show the relevance of dealing with polarized particles. We will see that it provides crucial tests for the Standard Model and can give us clear signatures to uncover new interactions. We will also discuss some striking experimental facts recently observed in hadronic collisions and their implications for current theoretical ideas. 43 refs., 10 figs.
Relativistic rigid particles: Classical tachyons and quantum anomalies
NASA Astrophysics Data System (ADS)
Govaerts, Jan
1993-03-01
Causal rigid particles whose action includes an arbitrary dependence on the world-line extrinsic curvature are considered. General classes of solutions are constructed, including causal tachyonic ones. The Hamiltonian formulation is developed in detail except for one degenerate situation for which only partial results are given and requiring a separate analysis. However, for otherwise generic rigid particles, the precise specification of Hamiltonian gauge symmetries is obtained with in particular the identification of the Teichmüller and modular spaces for these systems. Finally, canonical quantisation of the generic case is performed paying special attention to the phase space restriction due to causal propagation. A mixed Lorenz-gravitational anomaly is found in the commutator of Lorentz boosts with world-line reparametrisations. The subspace of gauge invariant physical states is therefore not invariant under Lorentz transformations. Consequences for rigid strings and membranes are also discussed.
ERIC Educational Resources Information Center
Barnes, Marianne B.; Garner, James; Reid, David
2004-01-01
In this article we use the pendulum as the vehicle for discussing the transition from classical to quantum physics. Since student knowledge of the classical pendulum can be generalized to all harmonic oscillators, we propose that a quantum analysis of the pendulum can lead students into the unanticipated consequences of quantum phenomena at the…
ERIC Educational Resources Information Center
Barnes, Marianne B.; Garner, James; Reid, David
2004-01-01
In this article we use the pendulum as the vehicle for discussing the transition from classical to quantum physics. Since student knowledge of the classical pendulum can be generalized to all harmonic oscillators, we propose that a quantum analysis of the pendulum can lead students into the unanticipated consequences of quantum phenomena at the
A hot particle training program for health physics technicians
Russell, M.J.; Lewis, M.M.; Rigby, W.F.; Warnock, R.V. )
1988-02-01
The measures that are needed to detect and control hot particles (irradiated fuel fragments and activated stellite particles) are quite different from the normal routine at nuclear power pants, and as a result, special training is needed. This article outlines the development of the San Onofre Nuclear Generating Station's Hot Particle Training Program for Health Physics Technicians, including the job and task analysis, the training objectives, the training materials, and the implementation and evaluation of the training program. In this paper the management, attitudinal, and technical goals of the training program are presented along with examples of training objectives and excerpts from the student handbook.
Few body problems in nuclear and particle physics
Carlson, J.A.
1983-01-01
Interaction models are developed in nuclear and particle physics, and properties of few body systems are calculated in terms of these models. In nuclear physics, realistic three nucleon interaction (TNI) models are developed and applied to three and four body nuclei. In particle physics, a semi-relativistic quark model is developed and hadron spectra are calculated. First described is the interaction models and their theoretical basis. The NN interaction models are reviewed and then two pion exchange models of TNI are discussed. Additionally, a semi-relativistic quark model is presented based upon flux tubes and the one gluon exchange interaction. The techniques of solving the Schroedinger equation for few body systems are discussed. The variational Monte Carlo method, which is use for these calculations, is presented in some detail, and the Faddeev and GFMC methods are reviewed briefly. Results obtained for simple model interactions are compared with the various methods, and a technique which allows calculations of particle unstable states to be performed is also developed. Finally, the results are compared with experiment. In nuclear physics, the binding energy, rms radii, charge form factors, magnetic moments, and coulomb energy for the ground states of three and four body nuclei are calculated. Results of calculations of scattering states in /sup 4/He are presented. In particle physics, the spectra of baryons made up of up and down quarks, and mesons consisting of both light and heavy quarks are calculated.
Nuclear and particle physics, astrophysics and cosmology (NPAC) capability review
Redondo, Antonio
2010-01-01
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.
Fractional dynamics and the Standard Model for particle physics
NASA Astrophysics Data System (ADS)
Goldfain, Ervin
2008-09-01
Fractional dynamics is an attractive framework for understanding the complex phenomena that are likely to emerge beyond the energy range of the Standard Model for particle physics (SM). Using fractional dynamics and complex-scalar field theory as a baseline, our work explores how physics on the high-energy scale may help solve some of the open questions surrounding SM. Predictions are shown to be consistent with experimental results.
Quantum radiation produced by a uniformly accelerating charged particle in thermal random motion
NASA Astrophysics Data System (ADS)
Oshita, Naritaka; Yamamoto, Kazuhiro; Zhang, Sen
2016-04-01
We investigate the properties of quantum radiation produced by a uniformly accelerating charged particle undergoing thermal random motion, which originates from the coupling to the vacuum fluctuations of the electromagnetic field. Because the thermal random motion is regarded to result from the Unruh effect, the quantum radiation might give us hints of the Unruh effect. The energy flux of the quantum radiation is negative and smaller than that of Larmor radiation by one order in a /m , where a is the constant acceleration and m is the mass of the particle. Thus, the quantum radiation appears to be a suppression of the classical Larmor radiation. The quantum interference effect plays an important role in this unique signature. The results are consistent with the predictions of a model consisting of a particle coupled to a massless scalar field as well as those of the previous studies on the quantum effect on the Larmor radiation.
Research accomplishments and future goals in particle physics
Not Available
1990-11-30
This document presents our proposal to continue the activities of Boston University researchers in high energy physics research. We have a broad program of participation in both non-accelerator and accelerator-based efforts. High energy research at Boston University has a special focus on the physics program of the Superconducting Supercollider. We are active in research and development for detector subsystems, in the design of experiments, and in study of the phenomenology of the very high energy interactions to be observed at the SSC. The particular areas discussed in this paper are: colliding beams physics; accelerator design physics; MACRO project; proton decay project; theoretical particle physics; muon G-2 project; fast liquid scintillators; SSCINTCAL project; TRD project; massively parallel processing for the SSC; and physics analysis and vertex detector upgrade at L3.
Magnetic particle motions within living cells. Physical theory and techniques.
Valberg, P A; Butler, J P
1987-01-01
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. PMID:3676435
Deep inelastic scaling in nuclear and particle physics
West, G.B.
1988-01-01
These lectures are intended to be a pedagogical introduction to some of the ideas and concepts concerning scaling phenomena which arise in nuclear and particle physics. Topics discussed are: classical scaling and dimensional analysis; non-relativistic treatment; dynamics and scaling; y-scaling; and relativistic treatment (QCD). 22 refs., 16 figs. (LSP)
Research in elementary particle physics. [Ohio State Univ. , Columbus
Not Available
1992-01-01
Experimental and theoretical work on high energy physics is reviewed. Included are preparations to study high-energy electron-proton interactions at HERA, light-cone QCD, decays of charm and beauty particles, neutrino oscillation, electron-positron interactions at CLEO II, detector development, and astrophysics and cosmology.
My 50 years of research in particle physics
Sugawara, Hirotaka
2010-01-01
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
Stochastic limit method and interference in quantum many-particle systems
NASA Astrophysics Data System (ADS)
Aref'eva, I. Ya.; Volovich, I. V.; Kozyrev, S. V.
2015-06-01
We consider the problem of excitation energy transfer in quantum many-particle systems with a dipole interaction. The considered exciton transfer mechanism is based on quantum interference. We show that by a special choice of interaction parameters, an enhancement of the exciton transfer to a sink and suppression of the transfer to alternative sinks can be achieved. The enhancement is proportional to the number of particles in the system. We use the quantum stochastic limit method to describe the dynamics. We indicate possible applications of the proposed mechanism to quantum processes in photosynthesis.
Physical characterization of quantum devices from nonlocal correlations
NASA Astrophysics Data System (ADS)
Bancal, Jean-Daniel; Navascués, Miguel; Scarani, Valerio; Vértesi, Tamás; Yang, Tzyh Haur
2015-02-01
In the device-independent approach to quantum information theory, quantum systems are regarded as black boxes that, given an input (the measurement setting), return an output (the measurement result). These boxes are then treated regardless of their actual internal working. In this paper we develop swap, a theoretical concept that, in combination with the tool of semidefinite methods for the characterization of quantum correlations, allows us to estimate physical properties of the black boxes from the observed measurement statistics. We find that the swap tool provides bounds orders of magnitude better than previously known techniques (e.g., for a Clauser-Horne-Shimony-Holt violation larger than 2.57, swap predicts a singlet fidelity greater than 70 % ). This method also allows us to deal with hitherto intractable cases such as robust device-independent self-testing of nonmaximally entangled two-qutrit states in the Collins-Gisin-Linden-Massar-Popescu scenario (for which Jordan's lemma does not apply) and the device-independent certification of entangled measurements. We further apply the swap method to relate nonlocal correlations to work extraction and quantum dimensionality, hence demonstrating that this tool can be used to study a wide variety of properties relying on the sole knowledge of accessible statistics.
Hadron Physics from Superconformal Quantum Mechanics and Its Light-Front Holographic Embedding
NASA Astrophysics Data System (ADS)
de Téramond, Guy F.
2016-02-01
The complex nonperturbative color-confining dynamics of QCD is well captured in a semiclassical effective theory based on superconformal quantum mechanics and its extension to the light-front. I describe here how this new approach to hadron physics incorporates confinement, the appearance of nearly massless pseudoscalar particles, and Regge spectroscopy consistent with experiment. It also gives remarkable connections between the meson and baryon spectrum across the light and heavy-light hadron spectrum. I also briefly discuss how higher spin states are consistently described in this framework by the holographic embedding of the superconformal theory in a higher dimensional semiclassical gravity theory.
Current experiments in elementary particle physics. Revision 1-85
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
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.
Particle acceleration, transport and turbulence in cosmic and heliospheric physics
NASA Technical Reports Server (NTRS)
Matthaeus, W.
1992-01-01
In this progress report, the long term goals, recent scientific progress, and organizational activities are described. The scientific focus of this annual report is in three areas: first, the physics of particle acceleration and transport, including heliospheric modulation and transport, shock acceleration and galactic propagation and reacceleration of cosmic rays; second, the development of theories of the interaction of turbulence and large scale plasma and magnetic field structures, as in winds and shocks; third, the elucidation of the nature of magnetohydrodynamic turbulence processes and the role such turbulence processes might play in heliospheric, galactic, cosmic ray physics, and other space physics applications.
Introduction to the Spin Physics of Relativistic Particles
NASA Astrophysics Data System (ADS)
Ternov, I. M.
1997-08-01
Problems of Spin's theory of relativistic Particles, the Dynamics of Spin during its motion in an external electromagnetic field, the problem of the Spin's and Anomalous Magnetic Moment of the electron (AMM) measurement, as well as some polarization and spin effects in electroweak fermionic interactions, moving in an external electromagnetic field has been examined. Problems of Engineering Physics of the Spin were also put into discussion: Polarized beams creation and Polarization Guidance. A review of achievements of the High Energy Physics in the area of application of relativistic beams with oriented spin has been given. The book is designed for Postgraduate Students of Universities Physics Departments.
A Survey of Physical Principles Attempting to Define Quantum Mechanics
NASA Astrophysics Data System (ADS)
Oas, Gary; Acacio de Barros, J.
Quantum mechanics, one of the most successful theories in the history of science, was created to account for physical systems not describable by classical physics. Though it is consistent with all experiments conducted thus far, many of its core concepts (amplitudes, global phases, etc.) can not be directly accessed and its interpretation is still the subject of intense debate, more than 100 years since it was introduced. So, a fundamental question is why this particular mathematical model is the one that nature chooses, if indeed it is the correct model. In the past two decades there has been a renewed effort to determine what physical or informational principles define quantum mechanics. In this chapter, recent attempts at establishing reasonable physical principles are reviewed and their degree of success is tabulated. An alternative approach using joint quasi-probability distributions is shown to provide a common basis of representing most of the proposed principles. It is argued that having a common representation of the principles can provide intuition and guidance to relate current principles or advance new principles. The current state of affairs, along with some alternative views are discussed.
Integrating particle physical geometry into composting degradation kinetics.
Wang, Yongjiang; Ai, Ping
2016-01-01
The study was carried out to integrate physical geometry of compost particle with degradation kinetics to model biological reactions, which revealing additional dynamic approaches. A sphere and its circumscribing cube were used to represent compost particles. An inner sphere, representing anaerobic zone, was introduced to describe variations of substrate volume without sufficient oxygen supply. Degradation of soluble substrates and hydrolysis of insoluble substrates were associated with the particle geometry. Transportation of soluble substrates produced from hydrolysis was expressed using Fick's law. Through the integration of degradation kinetics with geometry models, degradation models could describe varying volume of composting materials involving aerobic or anaerobic digestion and transportation of soluble substrates in a unit compost particle. PMID:26520491
Physical and magnetic properties of highly anisotropic cobalt ferrite particles
NASA Astrophysics Data System (ADS)
Virden, A.; Wells, S.; O'Grady, K.
2007-09-01
Highly crystalline cobalt ferrite nanoparticles have been prepared in order to investigate the cubic anisotropy of these materials. The particles were prepared by co-precipitation and the decomposition of an organo-metallic complex. Physical characterization was carried out by TEM from which it was determined that the samples had median particle sizes between 5.1 and 12.5 nm. The crystallinity of the particles was investigated by high-resolution TEM. Magnetic measurements of remanence and coercivity as a function of temperature were carried out using vibrating sample magnetometers. Squarenesses of above 0.5 were measured at low temperatures confirming the cubic anisotropy of the materials. An anisotropy field of 1.6 T was extracted from the measurement of coercivity as a function of temperature for highly crystalline samples. The large magnetocrystalline anisotropy leads to these particles potential applications as magnetic inks and hysteresis heating for biomedical uses.
Conservation-law-induced quantum limits for physical realizations of the quantum NOT gate
NASA Astrophysics Data System (ADS)
Karasawa, Tokishiro; Ozawa, Masanao
2007-03-01
In recent investigations, it has been found that conservation laws generally lead to precision limits on quantum computing. Lower bounds of the error probability have been obtained for various logic operations from the commutation relation between the noise operator and the conserved quantity or from the recently developed universal uncertainty principle for the noise-disturbance trade-off in general measurements. However, the problem of obtaining the precision limit to realizing the quantum NOT gate has eluded a solution from these approaches. Here, we develop a method for this problem based on analyzing the trace distance between the output state from the realization under consideration and the one from the ideal gate. Using the mathematical apparatus of orthogonal polynomials, we obtain a general lower bound on the error probability for the realization of the quantum NOT gate in terms of the number of qubits in the control system under conservation of the total angular momentum of the computational qubit plus the control system along the direction used to encode the computational basis. The lower bound turns out to be more stringent than one might expect from previous results. Our method is expected to lead to more accurate estimates for physical realizations of various types of quantum computations under conservation laws and to contribute to related problems such as the accuracy of programmable quantum processors.
A 2D Quantum Walk Simulation of Two-Particle Dynamics
NASA Astrophysics Data System (ADS)
Schreiber, Andreas; Gábris, Aurél; Rohde, Peter P.; Laiho, Kaisa; Štefaňák, Martin; Potoček, Václav; Hamilton, Craig; Jex, Igor; Silberhorn, Christine
2012-04-01
Multidimensional quantum walks can exhibit highly nontrivial topological structure, providing a powerful tool for simulating quantum information and transport systems. We present a flexible implementation of a two-dimensional (2D) optical quantum walk on a lattice, demonstrating a scalable quantum walk on a nontrivial graph structure. We realized a coherent quantum walk over 12 steps and 169 positions by using an optical fiber network. With our broad spectrum of quantum coins, we were able to simulate the creation of entanglement in bipartite systems with conditioned interactions. Introducing dynamic control allowed for the investigation of effects such as strong nonlinearities or two-particle scattering. Our results illustrate the potential of quantum walks as a route for simulating and understanding complex quantum systems.
PREFACE: International Conference on Particle Physics and Astrophysics (ICPPA-2015)
NASA Astrophysics Data System (ADS)
2016-02-01
The International Conference on Particle Physics and Astrophysics (ICPPA-2015) was held in Moscow, Russia, from October 5 to 10, 2015. The conference is organized by Center of Fundamental Research and Particle Physics of National Research Nuclear University ''MEPhI''. The aim of the Conference is to promote contacts between scientists and development of new ideas in fundamental research. We bring together experts and young scientists working on experimental and theoretical aspects of nuclear, particle, astroparticle physics and cosmology. The conference covers a wide range of topics such as accelerator physics, (astro) particle physics, cosmic rays, cosmology and methods of experimental physics - detectors and instruments. These directions are unified by development of the Standard Model (SM) which is evidently not complete. There are deviations from the Standard Model - neutrino oscillations, the dark matter existence. Together with strong interactions, they are main subjects of the Conference. New results from LHC collider as well as its future upgrade are discussed with the Higgs as the main point for discussion. Substantial development of experimental tools for astrophysical observations and new results from cosmic ray experiments is one of the main subjects of the conference. Various aspects of strong interaction are discussed. Among them: Charmonium and Bottomonium states, Flavor physics at Super B factories, Exotic Nuclei in Astrophysics. Another subject for discussion is the neutrino physics, promising and unique way to get new knowledge. In this content, several talks on BOREXINO experiment where new results in neutrino oscillations are presented. Special session is devoted to PAMELA experiment - 9 years in orbit and to the future GAMMA-400 gamma-ray telescope with following main scientific goals: indirect dark matter origin study by the gamma-ray astronomy methods, discrete astrophysical sources observations, diffuse background γ-emission analysis, investigation of high energy γ-emission from GRBs and other astrophysical objects including Sun, explore of high energy e-e+ fluxes, research of high energy light nuclei fluxes. Several talks concern the cosmic ray physics with high energy muons in large volume detectors - IceCube, NEVOD are among them. Also γ-quanta and charged particles generation in astrophysical sources and planets magnetospheres were discussed in the frameworks of Cosmic Rays subsection. Cosmological problems such as an origin and features of the dark matter, space reionization, smallness of the cosmological constant and black hole origin are discussed at the theoretical section of the conference. Special workshops are devoted to NEVOD experiment, Pamela Experiment, SiPM and Electronics.
Quantum work statistics of charged Dirac particles in time-dependent fields
NASA Astrophysics Data System (ADS)
Deffner, Sebastian; Saxena, Avadh
2015-09-01
The quantum Jarzynski equality is an important theorem of modern quantum thermodynamics. We show that the Jarzynski equality readily generalizes to relativistic quantum mechanics described by the Dirac equation. After establishing the conceptual framework we solve a pedagogical, yet experimentally relevant, system analytically. As a main result we obtain the exact quantum work distributions for charged particles traveling through a time-dependent vector potential evolving under Schrdinger as well as under Dirac dynamics, and for which the Jarzynski equality is verified. Special emphasis is put on the conceptual and technical subtleties arising from relativistic quantum mechanics.
Quantum work statistics of charged Dirac particles in time-dependent fields
Deffner, Sebastian; Saxena, Avadh
2015-09-28
The quantum Jarzynski equality is an important theorem of modern quantum thermodynamics. We show that the Jarzynski equality readily generalizes to relativistic quantum mechanics described by the Dirac equation. After establishing the conceptual framework we solve a pedagogical, yet experimentally relevant, system analytically. As a main result we obtain the exact quantum work distributions for charged particles traveling through a time-dependent vector potential evolving under Schrödinger as well as under Dirac dynamics, and for which the Jarzynski equality is verified. Thus, special emphasis is put on the conceptual and technical subtleties arising from relativistic quantum mechanics.
Quantum work statistics of charged Dirac particles in time-dependent fields
Deffner, Sebastian; Saxena, Avadh
2015-09-28
The quantum Jarzynski equality is an important theorem of modern quantum thermodynamics. We show that the Jarzynski equality readily generalizes to relativistic quantum mechanics described by the Dirac equation. After establishing the conceptual framework we solve a pedagogical, yet experimentally relevant, system analytically. As a main result we obtain the exact quantum work distributions for charged particles traveling through a time-dependent vector potential evolving under Schrdinger as well as under Dirac dynamics, and for which the Jarzynski equality is verified. Thus, special emphasis is put on the conceptual and technical subtleties arising from relativistic quantum mechanics.
Quantum work statistics of charged Dirac particles in time-dependent fields.
Deffner, Sebastian; Saxena, Avadh
2015-09-01
The quantum Jarzynski equality is an important theorem of modern quantum thermodynamics. We show that the Jarzynski equality readily generalizes to relativistic quantum mechanics described by the Dirac equation. After establishing the conceptual framework we solve a pedagogical, yet experimentally relevant, system analytically. As a main result we obtain the exact quantum work distributions for charged particles traveling through a time-dependent vector potential evolving under Schrödinger as well as under Dirac dynamics, and for which the Jarzynski equality is verified. Special emphasis is put on the conceptual and technical subtleties arising from relativistic quantum mechanics. PMID:26465456
How to upload a physical quantum state into correlation space
Morimae, Tomoyuki
2011-04-15
In the framework of the computational tensor network [Phys. Rev. Lett. 98, 220503 (2007)], the quantum computation is performed in a virtual linear space called the correlation space. It was recently shown [Phys. Rev. Lett. 103, 050503 (2009)] that a state in a correlation space can be downloaded to the real physical space. In this paper, conversely, we study how to upload a state from a real physical space to the correlation space. After showing the impossibility of cloning a state between a real physical space and the correlation space, we propose a simple teleportation-like method of uploading. This method also enables the Gottesman-Chuang gate teleportation trick and entanglement swapping in the virtual-real hybrid setting. Furthermore, compared with the inverse of the downloading method by Cai et al. [Phys. Rev. Lett. 103, 050503 (2009)], which also works to upload, the proposed uploading method has several advantages.
Physical realization of quantum teleportation for a nonmaximal entangled state
Tanaka, Yoshiharu; Asano, Masanari; Ohya, Masanori
2010-08-15
Recently, Kossakowski and Ohya (K-O) proposed a new teleportation scheme which enables perfect teleportation even for a nonmaximal entangled state [A. Kossakowski and M. Ohya, Infinite Dimensional Analysis Quantum Probability and Related Topics 10, 411 (2007)]. To discuss a physical realization of the K-O scheme, we propose a model based on quantum optics. In our model, we take a superposition of Schroedinger's cat states as an input state being sent from Alice to Bob, and their entangled state is generated by a photon number state through a beam splitter. When the average photon number for our input states is equal to half the number of photons into the beam splitter, our model has high fidelity.
The physical underpinning of security proofs for quantum key distribution
NASA Astrophysics Data System (ADS)
Boileau, Jean Christian
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.
NASA Astrophysics Data System (ADS)
Robbin, J. M.
2007-07-01
he hallmark of a good book of problems is that it allows you to become acquainted with an unfamiliar topic quickly and efficiently. The Quantum Mechanics Solver fits this description admirably. The book contains 27 problems based mainly on recent experimental developments, including neutrino oscillations, tests of Bell's inequality, Bose Einstein condensates, and laser cooling and trapping of atoms, to name a few. Unlike many collections, in which problems are designed around a particular mathematical method, here each problem is devoted to a small group of phenomena or experiments. Most problems contain experimental data from the literature, and readers are asked to estimate parameters from the data, or compare theory to experiment, or both. Standard techniques (e.g., degenerate perturbation theory, addition of angular momentum, asymptotics of special functions) are introduced only as they are needed. The style is closer to a non-specialist seminar rather than an undergraduate lecture. The physical models are kept simple; the emphasis is on cultivating conceptual and qualitative understanding (although in many of the problems, the simple models fit the data quite well). Some less familiar theoretical techniques are introduced, e.g. a variational method for lower (not upper) bounds on ground-state energies for many-body systems with two-body interactions, which is then used to derive a surprisingly accurate relation between baryon and meson masses. The exposition is succinct but clear; the solutions can be read as worked examples if you don't want to do the problems yourself. Many problems have additional discussion on limitations and extensions of the theory, or further applications outside physics (e.g., the accuracy of GPS positioning in connection with atomic clocks; proton and ion tumor therapies in connection with the Bethe Bloch formula for charged particles in solids). The problems use mainly non-relativistic quantum mechanics and are organised into three sections: Elementary Particles, Nuclei and Atoms; Quantum Entanglement and Measurement; and Complex Systems. The coverage is not comprehensive; there is little on scattering theory, for example, and some areas of recent interest, such as topological aspects of quantum mechanics and semiclassics, are not included. The problems are based on examination questions given at the École Polytechnique in the last 15 years. The book is accessible to undergraduates, but working physicists should find it a delight.
Ranzoni, Andrea; den Hamer, Anniek; Karoli, Tomislav; Buechler, Joseph; Cooper, Matthew A
2015-06-16
Fluorescent labels are widely employed in biomarker quantification and diagnostics, however they possess narrow Stokes shifts and can photobleach, limiting multiplexed detection applications and compromising sensitivity. In contrast, quantum dots do not photobleach and have much wider Stokes shifts, but a paucity of robust surface attachment chemistries for bioconjugation has limited their uptake in biomedical diagnostics. We report a novel class of biofunctional fluorescent labels based on trapping of ∼10(4) quantum dots within a core nanoparticle. The doped particles act as scaffolds for generation of a multilayered shell consisting of a functionalized hydrophilic polymer with covalently attached receptors for analyte capture. These constructs, which conceptually resemble a papaya fruit, are chemically stable, remain monodispersed for >6 months in buffer, and show utility in immunoassay applications. Using monoclonal antibody fragments against nonstructural protein dengue NS1, an early biomarker for dengue fever, antibody immobilization capacity was 75-fold higher compared with traditional carbodiimide protein coupling. In the model dengue immunoassay, we observed a 15-fold lower limit of detection and 4-fold higher fluorescence intensity with the "papaya particles" compared to current "best-in-class" commercial reagents. Direct deployment in human serum allowed sensitive detection of different NS1 serotypes with lower limits of detection within the clinically relevant range (1-10 ng/mL), and sufficient specificity for identification of the dengue serotype was achieved for concentrations >10 ng/mL (DV1-3) and >50 ng/mL (DV4). The combination of chemical and physical stability and high binding capacity combined with the intrinsic advantages of quantum dots may enable more simple, robust diagnostic assays in the future. PMID:25971296
NASA Astrophysics Data System (ADS)
Foley, Jonathan J., IV; Mazziotti, David A.
2012-07-01
Quantum measurements provide a trove of information about a quantum system or process without solution of the Schrödnger equation, and in principle, the associated density matrix is a function of these measurements. Inversion of the measurements can produce an estimate of the density matrix, but this estimate may be unphysical, especially when the measurements are noisy or incomplete. We develop a general approach based on semidefinite programming [D. A. Mazziotti, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.106.083001 106, 083001 (2011)] for reconstructing the density matrix from quantum measurements which leads naturally to nonnegative solutions, a critical attribute of physically realistic solutions. We discuss the use of this methodology for reconstructing p-particle reduced density matrices (p-RDMs) of N-particle systems where additional semidefinite constraints, known as N-representability conditions, are essential because they ensure that the p-RDM represents an N-particle system. Special attention is given to the N-representability conditions for the experimentally important cases where p=1 or 2. We apply the methodology to reconstructing the time-dependent quantum process of exciton transfer in a photosynthetic light-harvesting complex.
Huang, Yu; Guo, Feng; Li, Yongling; Liu, Yufeng
2015-01-01
Parameter estimation for fractional-order chaotic systems is an important issue in fractional-order chaotic control and synchronization and could be essentially formulated as a multidimensional optimization problem. A novel algorithm called quantum parallel particle swarm optimization (QPPSO) is proposed to solve the parameter estimation for fractional-order chaotic systems. The parallel characteristic of quantum computing is used in QPPSO. This characteristic increases the calculation of each generation exponentially. The behavior of particles in quantum space is restrained by the quantum evolution equation, which consists of the current rotation angle, individual optimal quantum rotation angle, and global optimal quantum rotation angle. Numerical simulation based on several typical fractional-order systems and comparisons with some typical existing algorithms show the effectiveness and efficiency of the proposed algorithm. PMID:25603158
Huang, Yu; Guo, Feng; Li, Yongling; Liu, Yufeng
2015-01-01
Parameter estimation for fractional-order chaotic systems is an important issue in fractional-order chaotic control and synchronization and could be essentially formulated as a multidimensional optimization problem. A novel algorithm called quantum parallel particle swarm optimization (QPPSO) is proposed to solve the parameter estimation for fractional-order chaotic systems. The parallel characteristic of quantum computing is used in QPPSO. This characteristic increases the calculation of each generation exponentially. The behavior of particles in quantum space is restrained by the quantum evolution equation, which consists of the current rotation angle, individual optimal quantum rotation angle, and global optimal quantum rotation angle. Numerical simulation based on several typical fractional-order systems and comparisons with some typical existing algorithms show the effectiveness and efficiency of the proposed algorithm. PMID:25603158
NASA Astrophysics Data System (ADS)
Horwitz, L. P.
2015-05-01
The most recent meeting took place at the University of Connecticut, Storrs, on June 9-13, 2014. This meeting forms the basis for the Proceedings that are recorded in this issue of the Journal of Physics: Conference Series. Along with the work of some of the founding members of the Association, we were fortunate to have lecturers from application areas that provided strong challenges for further developments in quantum field theory, cosmological problems, and in the dynamics of systems subject to accelerations and the effects of general relativity. Topics treated in this issue include studies of the dark matter problem, rotation curves, and, in particular, for the (relatively accessible) Milky Way galaxy, compact stellar objects, a composite particle model, and the properties of a conformally invariant theory with spontaneous symmetry breaking. The Stueckelberg theory is further investigated for its properties in producing bremsstrahlung and pair production and apparent superluminal effects, and, as mentioned above, the implications of low energy nuclear reactions for such off-shell theories. Other "proper time" theories are investigated as well, and a study of the clock synchronization problem is presented. A mathematical study of to quantum groupo associated with the Toda lattice and its implications for quantum field theory, as well as a phenomenological discussion of supernova mechanics as well as a semiclassical discussion of electron spin and the question of the compatibility of special relativity and the quantum theory. A careful analysis of the covariant Aharonov-Bohm effect is given as well. The quantization of massless fields and the relation to the Maxwell theory is also discussed. We wish to thank the participants who contributed very much through their lectures, personal discussions, and these papers, to the advancement of the subject and our understanding.
A guide to experimental particle physics literature, 1991-1996
Ezhela, V.V.; Filimonov, B.B.; Lugovsky, S.B.
1996-10-01
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.
Topics in the standard model of particle physics extension and fourth-order gravity
NASA Astrophysics Data System (ADS)
Ochoa, Joseph R.
In this thesis I present two possible signatures of quantum gravitational phenomenology. The first part of this thesis relates to a Lorentz symmetry violating extension of the standard model of particle physics. Here I show that a Chern-Simons type extension of the quantum electrodynamic (QED) sector of the standard model (SM) leads to the generation of circular polarization for photons. The polarization of scattered photons are analyzed using quantum field theoretic techniques and through the application of a generalized Boltzmann transport equation. In addition to the previously studied optical activity or birefringence effects induced by the particular interaction studied here, the Lorentz invariance violating interaction in question also leads to the generation of circular polarization. The possibility for observation of the effects in the cosmic microwave background (CMB) is discussed, although the circular polarization effects are shown to be at a level which is always sub-dominate to the birefringence effects. The second part of this thesis relates to a fourth-order modification to the general theory of relativity (GR) which has appeared as quantum corrections in the effective spectral action of noncommutative geometry (NCG). A term which is proportional to the square of the Weyl curvature is added to the Einstein-Hilbert action of GR and the the gravitational wave solutions of this modified theory are derived. The implications for the possibility of constraining the parameters of NCG through the analysis of data on the rate of orbit decay of binary pulsars is discussed.
NASA Astrophysics Data System (ADS)
Dehesa, J. S.; Martnez-Finkelshtein, A.; Sorokin, V. N.
2002-12-01
The asymptotics of the Boltzmann-Shannon information entropy as well as the Renyi entropy for the quantum probability density of a single-particle system with a confining (i.e., bounded below) power-type potential V(x)=x2k with k?N and x?R, is investigated in the position and momentum spaces within the semiclassical (WKB) approximation. It is found that for highly excited states both physical entropies, as well as their sum, have a logarithmic dependence on its quantum number not only when k=1 (harmonic oscillator), but also for any fixed k. As a by-product, the extremal case k?? (the infinite well potential) is also rigorously analyzed. It is shown that not only the position-space entropy has the same constant value for all quantum states, which is a known result, but also that the momentum-space entropy is constant for highly excited states.
Quantum chaotic scattering in atomic physics: Ericson fluctuations in photoionization.
Stania, Gernot; Walther, Herbert
2005-11-01
We report the first experimental investigation of quantum chaotic scattering in an atomic system: in strong crossed magnetic and electric fields in an energy regime beyond the ionization threshold, where the classical dynamics is an example of chaotic scattering. We find Ericson fluctuations in the spectra for photo excitation into this regime. This result constitutes the first observation of Ericson fluctuations in atomic and molecular physics. Furthermore, we confirm the prediction that chaotic scattering in the underlying classical dynamics implies Ericson fluctuations. PMID:16383982
Quantum Chaotic Scattering in Atomic Physics: Ericson Fluctuations in Photoionization
Stania, Gernot; Walther, Herbert
2005-11-04
We report the first experimental investigation of quantum chaotic scattering in an atomic system: {sup 85}Rb in strong crossed magnetic and electric fields in an energy regime beyond the ionization threshold, where the classical dynamics is an example of chaotic scattering. We find Ericson fluctuations in the spectra for photo excitation into this regime. This result constitutes the first observation of Ericson fluctuations in atomic and molecular physics. Furthermore, we confirm the prediction that chaotic scattering in the underlying classical dynamics implies Ericson fluctuations.
Quantum mechanical study of particles in ``softened'' potential boxes and wells
NASA Astrophysics Data System (ADS)
Salter, Lewis S.
1990-10-01
The ground-state energies and wave functions of a particle moving in one-dimensional potentials of the form V(x)=x2p, p=1,2,..., are obtained nearly exactly by iterative solution of the Schrdinger equation. These solutions are used as the ``experimental benchmark'' against which approximate solutions for the general case are tested. Both finite depth wells and infinitely deep wells are studied, as is the three-dimensional version (spherical symmetry, angular momentum quantum number l=0). The approach is aimed at student exploration of the physics of the family of potential wells, with emphasis upon connecting the familiar extreme cases, V(x)=x2 (simple harmonic oscillator) and the limiting case xk, k?? (square well).
NASA Astrophysics Data System (ADS)
Xiao-feng, Pang
2010-05-01
When the Schrödinger equation in quantum mechanics is replaced by the nonlinear Schrödinger equation to describe microscopic particles in nonlinear quantum systems, it has been verified that the nature of the particles differs considerably from those in quantum mechanics, where they are localized and have also wave-corpuscle duality due to the nonlinear interactions. In this case the influences of externally applied potentials in the nonlinear Schrödinger equation on the natures of the microscopic particles have been studied by a perturbation theory. The studied results show that the external potential can change the states of the microscopic particles, such as the positions, amplitude and wave forms, but cannot change the wave-corpuscle duality. In the meanwhile, we find further that the relationship between the external potential and change of positions of the particle satisfies the rule of motion of classical particles. Thus we know from this study that the kinetic energy term, ( ℏ2/2 m)∇ 2ϕ, in the nonlinear Schrödinger equation can only make the microscopic particles have a wave feature, but the nonlinear interaction b|ϕ|2ϕ determines its corpuscle feature, their combination makes the microscopic particles have a wave-corpuscle duality, and the potential V(r⇒,t)ϕ changes only the positions, amplitude and wave form of the particles. Therefore the nonlinear interaction plays an important role in determination of the wave-corpuscle duality of microscopic particles in quantum theory.
Tomonaga-Luttinger physics in electronic quantum circuits.
Jezouin, S; Albert, M; Parmentier, F D; Anthore, A; Gennser, U; Cavanna, A; Safi, I; Pierre, F
2013-01-01
In one-dimensional conductors, interactions result in correlated electronic systems. At low energy, a hallmark signature of the so-called Tomonaga-Luttinger liquids is the universal conductance curve predicted in presence of an impurity. A seemingly different topic is the quantum laws of electricity, when distinct quantum conductors are assembled in a circuit. In particular, the conductances are suppressed at low energy, a phenomenon called dynamical Coulomb blockade. Here we investigate the conductance of mesoscopic circuits constituted by a short single-channel quantum conductor in series with a resistance, and demonstrate a proposed link to Tomonaga-Luttinger physics. We reformulate and establish experimentally a recently derived phenomenological expression for the conductance using a wide range of circuits, including carbon nanotube data obtained elsewhere. By confronting both conductance data and phenomenological expression with the universal Tomonaga-Luttinger conductance curve, we demonstrate experimentally the predicted mapping between dynamical Coulomb blockade and the transport across a Tomonaga-Luttinger liquid with an impurity. PMID:23653214
Numerical simulation of quantum systems using the Particle-In-Cell method
NASA Astrophysics Data System (ADS)
Dirkmann, Sven; Youssef, Ziad; Hemke, Torben; Mussenbrock, Thomas
2014-10-01
The Particle-In-Cell (PIC) method is a very powerful method for studying the dynamics of plasmas. It has been primarily developed for tracking the charged particle trajectories subject to selfconsistent and external electromagnetic fields. Exploiting the power of modern computers, one is able to track the classical paths of tens of millions of particles at the same time. In the late 1980th, it was Dawson (and later Dauger) who had the idea to apply the PIC method to the classical part in the semiclassical approach to quantum systems via path integral methods. One could estimate that if a thousands of classical paths are sufficient to describe the dynamics of one quantum particle, then millions classical paths could describe the dynamics of a quantum particle system. A PIC code in the frame of a semiclassical approach would therefore enable the investigation of a number of quantum phenomena, e.g., optical properties, electrical properties, and, ultimately, chemical reactions. In this contribution we explain the use of the PIC code yapic (developed by the authors) in the frame of the path integral method and discuss the numerical results for simple quantum phenomena, i.e., the quantum harmonic oscillator and quantum tunneling. This work is supported by the German Research Foundation in the frame of FOR 2093.
The present status of experimental particle physics studies
NASA Astrophysics Data System (ADS)
Cline, D. B.
The status of elementary particle physics from an experimental viewpoint is briefly reviewed. The recent observation of the W and Z bosons and the t quark give added confidence in the unification of the electric and weak forces. The current null search for proton decay is discussed and some implications for other possible decay schemes (i.e., the Pati Salam decays) is given. Finally some effects observed in the UAI experiment at CERN may indicate new physics and guide us to the next step in experiments (monojets and same sign dimuons).
Physical sputtering of metallic systems by charged-particle impact
Lam, N.Q.
1989-12-01
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.
UCLA Particle Physics Research Group annual progress report
Nefkens, B.M.K.
1983-11-01
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.
MAJOR DETECOTRS IN ELEMENTARY PARTICLE PHYSICS - May 1985 Suppl.
Gidal, G.; Armstrong, B.; Rittenberg, A.
1985-05-01
This report is the second edition of a loose-leaf compendium of the properties and performance characteristics of the major detectors of elementary particle physics. This introduces the second edition of the LBL-91 Supplement 'Major Detectors in Elementary Particle Physics.' For some detectors the update merely documents minor modifications or provides additional references. Others have undergone major rebuilding or have been augmented with new subsystems. The new LEP, SLC, TRISTAN, BEPC, and FNAL detectors have had their designs fixed and are now under construction. Some detectors have completed their programs since the last edition and so are omitted. The use of colored loose-leaf paper should allow users to maintain a historical record of each detector. We again thank those physicists working with each detector who took the time to summarize its properties and supply us with the appropriate drawings.
Particle physics catalysis of thermal big bang nucleosynthesis.
Pospelov, Maxim
2007-06-01
We point out that the existence of metastable, tau>10(3) s, negatively charged electroweak-scale particles (X-) alters the predictions for lithium and other primordial elemental abundances for A>4 via the formation of bound states with nuclei during big bang nucleosynthesis. In particular, we show that the bound states of X- with helium, formed at temperatures of about T=10(8) K, lead to the catalytic enhancement of 6Li production, which is 8 orders of magnitude more efficient than the standard channel. In particle physics models where subsequent decay of X- does not lead to large nonthermal big bang nucleosynthesis effects, this directly translates to the level of sensitivity to the number density of long-lived X- particles (tau>10(5) s) relative to entropy of nX-/s less, approximately <3x10(-17), which is one of the most stringent probes of electroweak scale remnants known to date. PMID:17677895
Theoretical and Experimental Studies of Elementary Particle Physics
Evans, Harold G; Kostelecky, V Alan; Musser, James A
2013-07-29
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.
NASA Astrophysics Data System (ADS)
Mobley, Michael J.
2015-09-01
Hestenes has presented an integration of Schrdinger's zitterbewegung with the spin matrices of the Dirac equation, suggesting the electron can be modeled by a rapidly rotating dipole moment and a frequency related to the de Broglie frequency. He presents an elegant spacetime algebra that provides a reformulation of the Dirac equation that incorporates these real spin characteristics. A similar heuristic model for quantum particles has been derived by this author from a different, quasi-classical premise: That the most fundamental subcomponents of quantum particles all travel at a constant speed of light. Time is equated with the spatial displacement of these subcomponents - the speed of light is the speed of time. This approach suggests a means of integrating special relativity and quantum mechanics with the same concept of time. The relativistic transformation of spinning quantum particles create the appearance of additional, compactified spatial dimensions that can be correlated with the complex phase of the spin matrices as in the Dirac formalism. This paper further examines the convergence on such new models for quantum particles built on this rapid motion of particle subcomponents. The modeling leverages a string-like heuristic for particle subcomponents and a revised description for the wave-like properties of particles. This examination provides useful insights to the real spatial geometries and interactions of electrons and photons.
Quantum entanglement of identical particles by standard information-theoretic notions.
Lo Franco, Rosario; Compagno, Giuseppe
2016-01-01
Quantum entanglement of identical particles is essential in quantum information theory. Yet, its correct determination remains an open issue hindering the general understanding and exploitation of many-particle systems. Operator-based methods have been developed that attempt to overcome the issue. Here we introduce a state-based method which, as second quantization, does not label identical particles and presents conceptual and technical advances compared to the previous ones. It establishes the quantitative role played by arbitrary wave function overlaps, local measurements and particle nature (bosons or fermions) in assessing entanglement by notions commonly used in quantum information theory for distinguishable particles, like partial trace. Our approach furthermore shows that bringing identical particles into the same spatial location functions as an entangling gate, providing fundamental theoretical support to recent experimental observations with ultracold atoms. These results pave the way to set and interpret experiments for utilizing quantum correlations in realistic scenarios where overlap of particles can count, as in Bose-Einstein condensates, quantum dots and biological molecular aggregates. PMID:26857475
Quantum entanglement of identical particles by standard information-theoretic notions
NASA Astrophysics Data System (ADS)
Lo Franco, Rosario; Compagno, Giuseppe
2016-02-01
Quantum entanglement of identical particles is essential in quantum information theory. Yet, its correct determination remains an open issue hindering the general understanding and exploitation of many-particle systems. Operator-based methods have been developed that attempt to overcome the issue. Here we introduce a state-based method which, as second quantization, does not label identical particles and presents conceptual and technical advances compared to the previous ones. It establishes the quantitative role played by arbitrary wave function overlaps, local measurements and particle nature (bosons or fermions) in assessing entanglement by notions commonly used in quantum information theory for distinguishable particles, like partial trace. Our approach furthermore shows that bringing identical particles into the same spatial location functions as an entangling gate, providing fundamental theoretical support to recent experimental observations with ultracold atoms. These results pave the way to set and interpret experiments for utilizing quantum correlations in realistic scenarios where overlap of particles can count, as in Bose-Einstein condensates, quantum dots and biological molecular aggregates.
Quantum entanglement of identical particles by standard information-theoretic notions
Lo Franco, Rosario; Compagno, Giuseppe
2016-01-01
Quantum entanglement of identical particles is essential in quantum information theory. Yet, its correct determination remains an open issue hindering the general understanding and exploitation of many-particle systems. Operator-based methods have been developed that attempt to overcome the issue. Here we introduce a state-based method which, as second quantization, does not label identical particles and presents conceptual and technical advances compared to the previous ones. It establishes the quantitative role played by arbitrary wave function overlaps, local measurements and particle nature (bosons or fermions) in assessing entanglement by notions commonly used in quantum information theory for distinguishable particles, like partial trace. Our approach furthermore shows that bringing identical particles into the same spatial location functions as an entangling gate, providing fundamental theoretical support to recent experimental observations with ultracold atoms. These results pave the way to set and interpret experiments for utilizing quantum correlations in realistic scenarios where overlap of particles can count, as in Bose-Einstein condensates, quantum dots and biological molecular aggregates. PMID:26857475
A Novel Quantum Blind Signature Scheme with Four-Particle Cluster States
NASA Astrophysics Data System (ADS)
Fan, Ling
2015-09-01
In an arbitrated quantum signature scheme, the signer signs the message and the receiver verifies the signature's validity with the assistance of the arbitrator. We present an arbitrated quantum blind signature scheme by measuring four-particle cluster states and coding. By using the special relationship of four-particle cluster states, we cannot only support the security of quantum signature, but also guarantee the anonymity of the message owner. It has a wide application to E-payment system, E-government, E-business, and etc.
A Novel Quantum Blind Signature Scheme with Four-Particle Cluster States
NASA Astrophysics Data System (ADS)
Fan, Ling
2016-03-01
In an arbitrated quantum signature scheme, the signer signs the message and the receiver verifies the signature's validity with the assistance of the arbitrator. We present an arbitrated quantum blind signature scheme by measuring four-particle cluster states and coding. By using the special relationship of four-particle cluster states, we cannot only support the security of quantum signature, but also guarantee the anonymity of the message owner. It has a wide application to E-payment system, E-government, E-business, and etc.
A Novel Quantum Blind Signature Scheme with Four-particle GHZ States
NASA Astrophysics Data System (ADS)
Fan, Ling; Zhang, Ke-Jia; Qin, Su-Juan; Guo, Fen-Zhuo
2016-02-01
In an arbitrated quantum signature scheme, the signer signs the message and the receiver verifies the signature's validity with the assistance of the arbitrator. We present an arbitrated quantum blind signature scheme by using four-particle entangled Greenberger-Horne-Zeilinger (GHZ) states. By using the special relationship of four-particle GHZ states, we cannot only support the security of quantum signature, but also guarantee the anonymity of the message owner. It has a wide application to E-payment system, E-government, E-business, and etc.
Research in particle physics. Progress report, June 1, 1992--January 31, 1993
Not Available
1992-09-01
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.
EDITORIAL: Focus on Dark Matter and Particle Physics
NASA Astrophysics Data System (ADS)
Aprile, Elena; Profumo, Stefano
2009-10-01
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
Life at the interface of particle physics and string theory
NASA Astrophysics Data System (ADS)
Schellekens, A. N.
2013-10-01
If the results of the first LHC run are not betraying us, many decades of particle physics are culminating in a complete and consistent theory for all nongravitational physics: the standard model. But despite this monumental achievement there is a clear sense of disappointment: many questions remain unanswered. Remarkably, most unanswered questions could just be environmental, and disturbingly to some the existence of life may depend on that environment. Meanwhile there has been increasing evidence that the seemingly ideal candidate for answering these questions, string theory, gives an answer few people initially expected: a large “landscape” of possibilities that can be realized in a multiverse and populated by eternal inflation. At the interface of “bottom-up” and “top-down” physics, a discussion of anthropic arguments becomes unavoidable. Developments in this area are reviewed, focusing especially on the last decade.
Quantum Correlations of Two Relativistic Spin-{1}/{2} Particles Under Noisy Channels
NASA Astrophysics Data System (ADS)
Mahdian, M.; Mojaveri, B.; Dehghani, A.; Makaremi, T.
2016-02-01
We study the quantum correlation dynamics of bipartite spin-{1}/{2} density matrices for two particles under Wigner rotations induced by Lorentz transformations which is transmitted through noisy channels. We compare quantum entanglement, geometric discord(GD), and quantum discord (QD) for bipartite relativistic spin-{1}/{2} states under noisy channels. We find out QD and GD tend to death asymptotically but a sudden change in the decay rate of the entanglement occurs under noisy channels. Also, bipartite relativistic spin density matrices are considered as a quantum channel for teleportation one-qubit state under the influence of depolarizing noise and compare fidelity for various velocities of observers.
Physical interactions of charged particles for radiotherapy and space applications.
Zeitlin, Cary
2012-11-01
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
The XXth International Workshop High Energy Physics and Quantum Field Theory
NASA Astrophysics Data System (ADS)
The Workshop continues a series of workshops started by the Skobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University (SINP MSU) in 1985 and conceived with the purpose of presenting topics of current interest and providing a stimulating environment for scientific discussion on new developments in theoretical and experimental high energy physics and physical programs for future colliders. Traditionally the list of workshop attendees includes a great number of active young scientists and students from Russia and other countries. This year Workshop is organized jointly by the SINP MSU and the Southern Federal University (SFedU) and will take place in the holiday hotel "Luchezarniy" (Effulgent) situated on the Black Sea shore in a picturesque natural park in the suburb of the largest Russian resort city Sochi - the host city of the XXII Olympic Winter Games to be held in 2014. The main topics to be covered are: Experimental results from the LHC. Tevatron summary: the status of the Standard Model and the boundaries on BSM physics. Future physics at Linear Colliders and super B-factories. Extensions of the Standard Model and their phenomenological consequences at the LHC and Linear Colliders: SUSY extensions of the Standard Model; particle interactions in space-time with extra dimensions; strings, quantum groups and new ideas from modern algebra and geometry. Higher order corrections and resummations for collider phenomenology. Automatic calculations of Feynman diagrams and Monte Carlo simulations. LHC/LC and astroparticle/cosmology connections. Modern nuclear physics and relativistic nucleous-nucleous collisions.
Future directions in particle and nuclear physics at multi-GeV hadron beam facilities
Geesaman, D.F.
1993-11-01
This report contains papers on the following topics in particle and nuclear physics: hadron dynamics; lepton physics; spin physics; hadron and nuclear spectroscopy; hadronic weak interactions; and Eta physics. These papers have been indexed separately elsewhere.
Quantum tunneling of massive spin-1 particles from non-stationary metrics
NASA Astrophysics Data System (ADS)
Sakalli, I.; Övgün, A.
2016-01-01
We focus on the HR of massive vector (spin-1) particles tunneling from Schwarzschild BH expressed in the Kruskal-Szekeres and dynamic Lemaitre coordinates. Using the Proca equation together with the Hamilton-Jacobi and the WKB methods, we show that the tunneling rate, and its consequence Hawking temperature are well recovered by the quantum tunneling of the massive vector particles.
Lan, Zhihao; Minář, Jiří; Levi, Emanuele; Li, Weibin; Lesanovsky, Igor
2015-11-13
The devil's staircase is a fractal structure that characterizes the ground state of one-dimensional classical lattice gases with long-range repulsive convex interactions. Its plateaus mark regions of stability for specific filling fractions which are controlled by a chemical potential. Typically, such a staircase has an explicit particle-hole symmetry; i.e., the staircase at more than half filling can be trivially extracted from the one at less than half filling by exchanging the roles of holes and particles. Here, we introduce a quantum spin chain with competing short-range attractive and long-range repulsive interactions, i.e., a nonconvex potential. In the classical limit the ground state features generalized Wigner crystals that--depending on the filling fraction--are composed of either dimer particles or dimer holes, which results in an emergent complete devil's staircase without explicit particle-hole symmetry of the underlying microscopic model. In our system the particle-hole symmetry is lifted due to the fact that the staircase is controlled through a two-body interaction rather than a one-body chemical potential. The introduction of quantum fluctuations through a transverse field melts the staircase and ultimately makes the system enter a paramagnetic phase. For intermediate transverse field strengths, however, we identify a region where the density-density correlations suggest the emergence of quasi-long-range order. We discuss how this physics can be explored with Rydberg-dressed atoms held in a lattice. PMID:26613435
NASA Astrophysics Data System (ADS)
Lan, Zhihao; Minář, Jiří; Levi, Emanuele; Li, Weibin; Lesanovsky, Igor
2015-11-01
The devil's staircase is a fractal structure that characterizes the ground state of one-dimensional classical lattice gases with long-range repulsive convex interactions. Its plateaus mark regions of stability for specific filling fractions which are controlled by a chemical potential. Typically, such a staircase has an explicit particle-hole symmetry; i.e., the staircase at more than half filling can be trivially extracted from the one at less than half filling by exchanging the roles of holes and particles. Here, we introduce a quantum spin chain with competing short-range attractive and long-range repulsive interactions, i.e., a nonconvex potential. In the classical limit the ground state features generalized Wigner crystals that—depending on the filling fraction—are composed of either dimer particles or dimer holes, which results in an emergent complete devil's staircase without explicit particle-hole symmetry of the underlying microscopic model. In our system the particle-hole symmetry is lifted due to the fact that the staircase is controlled through a two-body interaction rather than a one-body chemical potential. The introduction of quantum fluctuations through a transverse field melts the staircase and ultimately makes the system enter a paramagnetic phase. For intermediate transverse field strengths, however, we identify a region where the density-density correlations suggest the emergence of quasi-long-range order. We discuss how this physics can be explored with Rydberg-dressed atoms held in a lattice.
NASA Astrophysics Data System (ADS)
Godfrey, David Wayne
Many are beginning to see the promise that the quantum world has offered those who manage and lead organizations (Wheatley, 1992; Zohar, 1997). The Newtonian world is one in which all "things" are reduced to their smallest parts, separated, divided, and analyzed with predictability, with complete control being the ultimate goal. The quantum world is one of infinite possibilities, infinite fields of influence, and infinite relationships. The hallmark characteristics found in a manager who has been schooled in the quantum sciences are flexibility, responsiveness, synchronicity, serendipity, creativity, innovation, participation, and motivation. In a quantum organization there is the constant awareness of the whole system, but there is also diversity (wave or particle), which allows for self-organization that is based on the environment and its requirements. In the quantum world many paths lead from A to Z, and depending on the path chosen, numerous realities wait to unfold. It was the goal of this research to explore the changing of leader behaviors through exposure to the models and theories found in quantum physics. From a quantum perspective this behavior change is possible; the only question is the readiness, willingness, and ability of the leaders to allow their behaviors to be surfaced and challenged. These are indeed the greatest challenges for all people as they proceed through life and work---readiness for change, willingness to change, and ability to surface key areas where change is needed.
Major detectors in elementary-particle physics. [Portfolio
Gidal, G.; Armstrong, B.; Rittenberg, A.
1983-03-01
With the 1983 issue of LBL-91 we introduce a supplement - a folio of descriptions of the world's major elementary particle physics detectors. Modern high energy physics usually involves the use of massive, costly, carefully engineered, large solid angle detectors. These detectors require a long lead time for construction, are often integrated with an accelerator, accumulate data over many years, and are in reality a combination of numerous subsystems. As was the case with bubble chambers, many experiments are performed with the same data, or with data taken after relatively minor changes or additions to the detector configuration. These experiments are often reported in journals whose space limitations make repeated full descriptions of the detector impossible. The detailed properties and performance of the detector are usually described in a fragmented series of papers in more specialized, technologically oriented journals. New additions are often not well documented. Several detectors often make similar measurements and physicists want to make quick comparisons of their respective capabilities. Designers of new large detectors and even of smaller experiments need to know what already exists and what performance has been achieved. To aid the physics community, the Particle Data Group has produced this brief folio of the world's major large detectors. This first edition has some notable omissions: in particular, the bubble chambers and any associated spectrometers, and the still somewhat tentative LEP, SLC, and TRISTAN detectors.
Liquid xenon detectors for particle physics and astrophysics
Aprile, E.; Doke, T.
2010-07-15
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.
Elementary particle physics at the University of Florida. Annual report
Field, R.D.; Ramond, P.M.; Sikivie, P.
1995-12-01
This is the annual progress report of the University of Florida`s elementary particle physics group. The theoretical high energy physics group`s research covers a broad range of topics, including both theory and phenomenology. Present work of the experimental high energy physics group is directed toward the CLEO detector, with some effort going to B physics at Fermilab. The Axion Search project is participating in the operation of a large-scale axion detector at Lawrence Livermore National Laboratory, with the University of Florida taking responsibility for this experiment`s high-resolution spectrometer`s assembly, programming, and installation, and planning to take shifts during operation of the detector in FY96. The report also includes a continuation of the University`s three-year proposal to the United States Department of Energy to upgrade the University`s high-energy physics computing equipment and to continue student support, system manager/programmer support, and maintenance. Report includes lists of presentations and publications by members of the group.
Conceptual knowledge in quantum physics: Student reasoning about charge flow
NASA Astrophysics Data System (ADS)
Wittmann, Michael C.
2003-04-01
Understanding student thinking about microscopic models of physics is of increasing importance with the ongoing miniaturization of technology. In a multi-year study, collaborators and I have been investigating students reasoning about charge flow from a quantum perspective. Our work in physics education research addresses both issues of student understanding and analyses of research tools used in our work. A student's epistemological stance (be it knowledge as memorized information, knowledge from authority, or knowledge as invented stuff) that student from reasoning in productive ways while also shaping the inferences a researcher can make about how that student reasons about a particular phenomenon. I present an example of an individual student interview on charge flow in wires in which both student constraints and researcher constraints appear to strongly affect the course of the interview. In the first part of the interview, the student's focus on memorized knowledge prevents the researcher from learning about her detailed reasoning about current. In the second part of the interview, her focus on constructed knowledge provides the researcher with a picture of her reasoning about the physical mechanisms of charge flow.
Marietta Blau: Pioneer of Photographic Nuclear Emulsions and Particle Physics
NASA Astrophysics Data System (ADS)
Sime, Ruth Lewin
2013-03-01
During the 1920s and 1930s, Viennese physicist Marietta Blau (1894-1970) pioneered the use of photographic methods for imaging high-energy nuclear particles and events. In 1937 she and Hertha Wambacher discovered "disintegration stars" - the tracks of massive nuclear disintegrations - in emulsions exposed to cosmic radiation. This discovery launched the field of particle physics, but Blau's contributions were underrecognized and she herself was nearly forgotten. I trace Blau's career at the Institut für Radiumforschung in Vienna and the causes of this "forgetting," including her forced emigration from Austria in 1938, the behavior of her colleagues in Vienna during and after the National Socialist period, and the flawed Nobel decision process that excluded her from a Nobel Prize.
QBism and the Greeks: why a quantum state does not represent an element of physical reality
NASA Astrophysics Data System (ADS)
Fuchs, Christopher A.; Schack, Rdiger
2015-01-01
In QBism (or quantum Bayesianism) a quantum state does not represent an element of physical reality but an agent's personal probability assignments, reflecting his subjective degrees of belief about the future content of his experience. In this paper, we contrast QBism with hidden-variable accounts of quantum mechanics and show the sense in which QBism explains quantum correlations. QBism's agent-centered worldview can be seen as a development of ideas expressed in Schrdinger's essay Nature and the Greeks. This article was originally intended for the Quantum Foundations and Quantum Information 2013 Topical Issue.
Double-slit experiment with single wave-driven particles and its relation to quantum mechanics
NASA Astrophysics Data System (ADS)
Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T.; Bohr, Tomas
2015-07-01
In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006), 10.1103/PhysRevLett.97.154101] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.
Double-slit experiment with single wave-driven particles and its relation to quantum mechanics.
Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T; Bohr, Tomas
2015-07-01
In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics. PMID:26274269
Quantum secret sharing protocol based on four-dimensional three-particle entangled states
NASA Astrophysics Data System (ADS)
Xiang, Yi; Mo, Zhi Wen
2016-01-01
In this paper, we proposed a three-party quantum secret sharing (QSS) scheme using four-dimensional three-particle entangled states. In this QSS scheme, each agent can obtain a shadow of the secret key by performing single-particle measurements. Compared with the existing QSS protocol, this scheme has high efficiency and can resist the eavesdropping attack and entangle-measuring attack, which using three-particle entangled states are based on four-dimensional Hilbert space.
Semantic incompleteness of quantum physics and EPR-like paradoxes
NASA Astrophysics Data System (ADS)
Garola, Claudio
1993-10-01
In the approach to quantum physics (QP) forwarded by the author an a priori formalization of the observative language of the theory is yielded. It is shown here that this formalization allows one to avoid both ontological realism and verificationism, which are the philosophically opposed positions that are usually assumed in the debate on the paradoxes that seem to follow from the analysis of the Einstein, Podolsky, and Rosen (EPR) thought experiment. Some recent results are summarized (in particular, the semantical incompleteness of QP) obtained by the author in the framework of the aforesaid approach, and it is shown that they can be used in order to deal with some EPR-like paradoxes. Thus one can legitimately affirm that at least some of them can be a consequence of semantical ambiguities and of the acceptance of a philosophical dichotomy which is not logically unavoidable.
Quantum Hall physics with cold atoms in cylindrical optical lattices
NASA Astrophysics Data System (ADS)
?cki, Mateusz; Pichler, Hannes; Sterdyniak, Antoine; Lyras, Andreas; Lembessis, Vassilis E.; Al-Dossary, Omar; Budich, Jan Carl; Zoller, Peter
2016-01-01
We propose and study various realizations of a Hofstadter-Hubbard model on a cylinder geometry with fermionic cold atoms in optical lattices. The cylindrical optical lattice is created by copropagating Laguerre-Gauss beams, i.e., light beams carrying orbital angular momentum. By strong focusing of the light beams we create a real-space optical lattice in the form of rings, which are offset in energy. A second set of Laguerre-Gauss beams then induces a Raman-hopping between these rings, imprinting phases corresponding to a synthetic magnetic field (artificial gauge field). In addition, by rotating the lattice potential, we achieve a slowly varying flux through the hole of the cylinder, which allows us to probe the Hall response of the system as a realization of Laughlin's thought experiment. We study how in the presence of interactions fractional quantum Hall physics could be observed in this setup.
Ad Hoc Physical Hilbert Spaces in Quantum Mechanics
NASA Astrophysics Data System (ADS)
Fernández, Francisco M.; Garcia, Javier; Semorádová, Iveta; Znojil, Miloslav
2015-12-01
The overall principles of what is now widely known as PT-symmetric quantum mechanics are listed, explained and illustrated via a few examples. In particular, models based on an elementary local interaction V(x) are discussed as motivated by the naturally emergent possibility of an efficient regularization of an otherwise unacceptable presence of a strongly singular repulsive core in the origin. The emphasis is put on the constructive aspects of the models. Besides the overall outline of the formalism we show how the low-lying energies of bound states may be found in closed form in certain dynamical regimes. Finally, once these energies are found real we explain that in spite of a manifest non-Hermiticity of the Hamiltonian the time-evolution of the system becomes unitary in a properly amended physical Hilbert space.
Local State and Sector Theory in Local Quantum Physics
NASA Astrophysics Data System (ADS)
Ojima, Izumi; Okamura, Kazuya; Saigo, Hayato
2016-04-01
We define a new concept of local states in the framework of algebraic quantum field theory (AQFT). Local states are a natural generalization of states and give a clear vision of localization in the context of QFT. In terms of them, we can find a condition from which follows automatically the famous DHR selection criterion in DHR-DR theory. As a result, we can understand the condition as consequences of physically natural state preparations in vacuum backgrounds. Furthermore, a theory of orthogonal decomposition of completely positive (CP) maps is developed. It unifies a theory of orthogonal decomposition of states and order structure theory of CP maps. Using it, localized version of sectors is formulated, which gives sector theory for local states with respect to general reference representations.
Hydrodynamics of the Physical Vacuum: I. Scalar Quantum Sector
NASA Astrophysics Data System (ADS)
Sbitnev, Valeriy I.
2016-01-01
Physical vacuum is a special superfluid medium. Its motion is described by the Navier-Stokes equation having two slightly modified terms that relate to internal forces. They are the pressure gradient and the dissipation force because of viscosity. The modifications are as follows: (a) the pressure gradient contains an added term describing the pressure multiplied by the entropy gradient; (b) time-averaged viscosity is zero, but its variance is not zero. Owing to these modifications, the Navier-Stokes equation can be reduced to the Schrödinger equation describing behavior of a particle into the vacuum, which looks like a superfluid medium populated by enormous amount of virtual particle-antiparticle pairs.
Hydrodynamics of the Physical Vacuum: I. Scalar Quantum Sector
NASA Astrophysics Data System (ADS)
Sbitnev, Valeriy I.
2016-05-01
Physical vacuum is a special superfluid medium. Its motion is described by the Navier-Stokes equation having two slightly modified terms that relate to internal forces. They are the pressure gradient and the dissipation force because of viscosity. The modifications are as follows: (a) the pressure gradient contains an added term describing the pressure multiplied by the entropy gradient; (b) time-averaged viscosity is zero, but its variance is not zero. Owing to these modifications, the Navier-Stokes equation can be reduced to the Schrödinger equation describing behavior of a particle into the vacuum, which looks like a superfluid medium populated by enormous amount of virtual particle-antiparticle pairs.
UCLA Particle and Nuclear Physics Research Group, 1993 progress report
Nefkens, B.M.K.; Clajus, M.; Price, J.W.; Tippens, W.B.; White, D.B.
1993-09-01
The research programs of the UCLA Particle and Nuclear Physics Research Group, the research objectives, results of experiments, the continuing activities and new initiatives are presented. The primary goal of the research is to test the symmetries and invariances of particle/nuclear physics with special emphasis on investigating charge symmetry, isospin invariance, charge conjugation, and CP. Another important part of our work is baryon spectroscopy, which is the determination of the properties (mass, width, decay modes, etc.) of particles and resonances. We also measure some basic properties of light nuclei, for example the hadronic radii of {sup 3}H and {sup 3}He. Special attention is given to the eta meson, its production using photons, electrons, {pi}{sup {plus_minus}}, and protons, and its rare and not-so-rare decays. In Section 1, the physics motivation of our research is outlined. Section 2 provides a summary of the research projects. The status of each program is given in Section 3. We discuss the various experimental techniques used, the results obtained, and we outline the plans for the continuing and the new research. Details are presented of new research that is made possible by the use of the Crystal Ball Detector, a highly segmented NaI calorimeter and spectrometer with nearly 4{pi} acceptance (it was built and used at SLAC and is to be moved to BNL). The appendix contains an update of the bibliography, conference participation, and group memos; it also indicates our share in the organization of conferences, and gives a listing of the colloquia and seminars presented by us.
A one-dimensional lattice model for a quantum mechanical free particle
NASA Astrophysics Data System (ADS)
de La Torre, A. C.; Daleo, A.
2000-01-01
Two types of particles, A and B with their corresponding antiparticles, are defined in a onedimensional cyclic lattice with an odd number of sites. In each step of time evolution, each particle acts as a source for the polarization field of the other type of particle with nonlocal action but with an effect decreasing with the distance: A to \\cdots bar BBbar BBbar B \\cdots ;B to \\cdots Abar AAbar AA \\cdots . It is shown that the combined distribution of these particles obeys the time evolution of a free particle as given by quantum mechanics.
A Summer Research Experience in Particle Physics Using Skype
NASA Astrophysics Data System (ADS)
Johnston, Curran; Alexander, Steven; Mahmood, A. K.
2012-10-01
This last summer I did research in particle physics as part of a ``remote REU.'' This poster will describe that experience and the results of my project which was to experimentally verify the mass ranges of the Z' boson. Data from the LHC's Atlas detector was filtered by computers to select for likely Z boson decays; my work was in noting all instances of Z or Z' boson decays in one thousand events and their masses, separating the Z from Z' bosons, and generating histograms of the masses.
A guide to data in elementary particle physics
Yost, G.P.; Rittenberg, A.; Armstrong, B.; Ferguson, M. Jr.; Levine, B.S.; Simpson, K.H.; Trippe, T.G.; Visser, M.J.; Wagman, G.S.; Wohl, C.G.
1986-09-01
We present an indexed guide to experimental high energy physics literature for the years 1977 through 1985. While no actual data are included, approximately 9000 papers are indexed by Beam/Target/Momentum, Reaction/Momentum (including the final state), Particle, and Accelerator/Detector. All indices are cross-referenced via an ID to the paper's title and references in the ID/Reference/Title Index. Black marks (bleeder tabs) at the side of the page enable each section to be located quickly, using the Table of Contents on the back cover. The information presented in this guide is also publicly available on a regularly updated SLAC-SPIRES database called DATAGUIDE.
A Particle Model Explaining Mass and Relativity in a Physical Way
NASA Astrophysics Data System (ADS)
Giese, Albrecht
Physicists' understanding of relativity and the way it is handled is up to present days dominated by the interpretation of Albert Einstein, who related relativity to specific properties of space and time. The principal alternative to Einstein's interpretation is based on a concept proposed by Hendrik A. Lorentz, which uses knowledge of classical physics alone to explain relativistic phenomena. In this paper, we will show that on the one hand the Lorentz-based interpretation provides a simpler mathematical way of arriving at the known results for both Special and General Relativity. On the other hand, it is able to solve problems which have remained open to this day. Furthermore, a particle model will be presented, based on Lorentzian relativity and the quantum mechanical concept of Louis de Broglie, which explains the origin of mass without the use of the Higgs mechanism. It is based on the finiteness of the speed of light and provides classical results for particle properties which are currently only accessible through quantum mechanics.
Electron-hole quantum physics in ZnO
NASA Astrophysics Data System (ADS)
Versteegh, M. A. M.
2011-09-01
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.
Applications of gaseous particle detectors in physics and medicine
NASA Astrophysics Data System (ADS)
Sauli, Fabio
1995-08-01
The multi-wire proportional chamber, introduced in 1967 by Georges Charpak (recipient of the 1992 Nobel prize for physics) allows to achieve high-rate, fully electronics detection and localization of ionizing radiation. The myriad of devices inspired by this initial work generated a revolution in the conception of detectors for elementary particle physics experiments; examples are the time projection chamber, the drift chamber, the micro-strip gas chamber. After a brief introduction on the basic operating principles of the device, I will describe several examples of application of advanced gas detectors in medicine and biology and analyze the operating characteristics that make the new devices attractive when confronted with classic detectors.
Molecular Rotation Signals: Molecule Chemistry and Particle Physics
NASA Astrophysics Data System (ADS)
Grabow, Jens-Uwe
2015-06-01
Molecules - large or small - are attractive academic resources, with numerous questions on their chemical behaviour as well as problems in fundamental physics now (or still) waiting to be answered: Targeted by high-resolution spectroscopy, a rotating molecular top can turn into a laboratory for molecule chemistry or a laboratory for particle physics. Once successfully entrained (many species - depending on size and chemical composition - have insufficient vapour pressures or are of transient nature, such that specifically designed pulsed-jet sources are required for their transfer into the gas phase or in-situ generation) into the collision-free environment of a supersonic-jet expansion, each molecular top comes with its own set of challenges, theoretically and experimentally: Multiple internal interactions are causing complicated energy level schemes and the resulting spectra will be rather difficult to predict theoretically. Experimentally, these spectra are difficult to assess and assign. With today's broad-banded chirp microwave techniques, finding and identifying such spectral features have lost their major drawback of being very time consuming for many molecules. For other molecules, the unrivalled resolution and sensitivity of the narrow-banded impulse microwave techniques provide a window to tackle - at the highest precision available to date - fundamental questions in physics, even particle physics - potentially beyond the standard model. Molecular charge distribution, properties of the chemical bond, details on internal dynamics and intermolecular interaction, the (stereo-chemical) molecular structure (including the possibility of their spatial separation) as well as potential evidence for tiny yet significant interactions encode their signature in pure molecular rotation subjected to time-domain microwave spectroscopic techniques. Ongoing exciting technical developments promise rapid progress. We present recent examples from Hannover, new directions, and an outlook at the future of molecular rotation spectroscopy.
NASA Astrophysics Data System (ADS)
Roszak, K.; Cywiński, Ł.
2015-10-01
We study quantum teleportation via Bell-diagonal mixed states of two qubits in the context of the intrinsic properties of the quantum discord. We show that when the quantum-correlated state of the two qubits is used for quantum teleportation, the character of the teleportation efficiency changes substantially depending on the Bell-diagonal-state parameters, which can be seen when the worst-case-scenario or best-case-scenario fidelity is studied. Depending on the parameter range, one of two types of single-qubit states is hardest/easiest to teleport. The transition between these two parameter ranges coincides exactly with the transition between the range of classical correlation decay and quantum correlation decay characteristic for the evolution of the quantum discord. The correspondence provides a physical interpretation for the prominent feature of the decay of the quantum discord.
NASA Astrophysics Data System (ADS)
Palmer, T. N.
2012-12-01
This essay discusses a proposal that draws together the three great revolutionary theories of 20th Century physics: quantum theory, relativity theory and chaos theory. Motivated by the Bohmian notion of implicate order, and what in chaos theory would be described as a strange attractor, the proposal attributes special ontological significance to certain non-computable, dynamically invariant state-space geometries for the universe as a whole. Studying the phenomenon of quantum interference, it is proposed to understand quantum wave-particle duality, and indeed classical electromagnetism, in terms of particles in space time and waves on this state space geometry. Studying the EPR experiment, the acausal constraints that this invariant geometry provides on spatially distant degrees of freedom, provides a way for the underlying dynamics to be consistent with the Bell theorem, yet be relativistically covariant ("nonlocality without nonlocality"). It is suggested that the physical basis for such non-computable geometries lies in properties of gravity with the information irreversibility implied by black hole no-hair theorems being crucial. In conclusion it is proposed that quantum theory may be emergent from an extended theory of gravity which is geometric not only in space time, but also in state space. Such a notion would undermine most current attempts to "quantise gravity".
Multi-party quantum secret sharing with the single-particle quantum state to encode the information
NASA Astrophysics Data System (ADS)
Chen, Xiu-Bo; Niu, Xin-Xin; Zhou, Xin-Jie; Yang, Yi-Xian
2013-01-01
We present a three-party quantum secret sharing (QSS) scheme via the entangled Greenberger-Horne-Zeilinger state. In this scheme, the sender Alice encodes her arbitrary secret information by means of preparing a single-particle quantum state. The agent Bob obtains his shared information according to his hobby, while Charlie can easily calculate his shared information. The proposed scheme is secure. It is shown that even a dishonest agent, who may avoid the security checking, cannot obtain any useful information. Moreover, we further investigate the multi-party QSS scheme which allows most agents to predetermine their information.
NASA Astrophysics Data System (ADS)
Hey, Anthony J. G.; Walters, Patrick
This book provides a descriptive, popular account of quantum physics. The basic topics addressed include: waves and particles, the Heisenberg uncertainty principle, the Schroedinger equation and matter waves, atoms and nuclei, quantum tunneling, the Pauli exclusion principle and the elements, quantum cooperation and superfluids, Feynman rules, weak photons, quarks, and gluons. The applications of quantum physics to astrophyics, nuclear technology, and modern electronics are addressed.
Quantum superstring field theory in the B0-gauge and the physical scattering amplitudes
NASA Astrophysics Data System (ADS)
Naito, Seichi
1999-10-01
We propose the (BRST-invariant) quantum open superstring field theory in the "B0-gauge," based on Neveu-Schwarz (NS) strings in 1 picture and Ramond (R) strings in 1/2 picture. We give the propagators of these open NS and R superstrings. In order to obtain the BRST-invariant interaction terms among these superstrings, we modify the interaction terms among three superstrings (i.e., among NS-NS-NS and R-R-NS) by subtracting the infinite number of counter terms, each of which involves interaction terms among "more than four superstrings." The modified action can be obtained successively, so that resulting amplitudes in g-loops should become BRST invariant. Thus obtained amplitudes are referred to as the "amputated scatts," with the help of which the physical scattering amplitudes can be expressed. These physical scattering amplitudes among NB bosonic (NF fermionic) particles are calculated by using the analytic inlint gluing operator (which has already been proposed and used in the quantum bosonic string field theory "in the B0=0 gauge").
[Investigations in dynamics of gauge theories in theoretical particle physics
Not Available
1993-02-01
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.
Phase space dynamics and control of the quantum particles associated to hypergraph states
NASA Astrophysics Data System (ADS)
Berec, Vesna
2015-05-01
As today's nanotechnology focus becomes primarily oriented toward production and manipulation of materials at the subatomic level, allowing the performance and complexity of interconnects where the device density accepts more than hundreds devices on a single chip, the manipulation of semiconductor nanostructures at the subatomic level sets its prime tasks on preserving and adequate transmission of information encoded in specified (quantum) states. The presented study employs the quantum communication protocol based on the hypergraph network model where the numerical solutions of equations of motion of quantum particles are associated to vertices (assembled with device chip), which follow specific controllable paths in the phase space. We address these findings towards ultimate quest for prediction and selective control of quantum particle trajectories. In addition, presented protocols could represent valuable tool for reducing background noise and uncertainty in low-dimensional and operationally meaningful, scalable complex systems.
Early developments: Particle physics aspects of cosmic rays
NASA Astrophysics Data System (ADS)
Grupen, Claus
2014-01-01
Cosmic rays is the birthplace of elementary particle physics. The 1936 Nobel prize was shared between Victor Hess and Carl Anderson. Anderson discovered the positron in a cloud chamber. The positron was predicted by Dirac several years earlier. In subsequent cloud chamber investigations Anderson and Neddermeyer saw the muon, which for some time was considered to be a candidate for the Yukawa particle responsible for nuclear binding. Measurements with nuclear emulsions by Lattes, Powell, Occhialini and Muirhead clarified the situation by the discovery of the charged pions in cosmic rays. The cloud chamber continued to be a powerful instrument in cosmic ray studies. Rochester and Butler found V's, which turned out to be shortlived neutral kaons decaying into a pair of charged pions. Also Λ's, Σ's, and Ξ's were found in cosmic rays. But after that accelerators and storage rings took over. The unexpected renaissance of cosmic rays started with the search for solar neutrinos and the observation of the supernova 1987A. Cosmic ray neutrino results were best explained by the assumption of neutrino oscillations opening a view beyond the standard model of elementary particles. After 100 years of cosmic ray research we are again at the beginning of a new era, and cosmic rays may contribute to solve the many open questions, like dark matter and dark energy, by providing energies well beyond those of accelerators.
PREFACE: 6th International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics
NASA Astrophysics Data System (ADS)
Fring, Andreas; Jones, Hugh; Znojil, Miloslav
2008-06-01
Attempts to understand the quantum mechanics of non-Hermitian Hamiltonian systems can be traced back to the early days, one example being Heisenberg's endeavour to formulate a consistent model involving an indefinite metric. Over the years non-Hermitian Hamiltonians whose spectra were believed to be real have appeared from time to time in the literature, for instance in the study of strong interactions at high energies via Regge models, in condensed matter physics in the context of the XXZ-spin chain, in interacting boson models in nuclear physics, in integrable quantum field theories as Toda field theories with complex coupling constants, and also very recently in a field theoretical scenario in the quantization procedure of strings on an AdS5 x S5 background. Concrete experimental realizations of these types of systems in the form of optical lattices have been proposed in 2007. In the area of mathematical physics similar non-systematic results appeared sporadically over the years. However, intensive and more systematic investigation of these types of non- Hermitian Hamiltonians with real eigenvalue spectra only began about ten years ago, when the surprising discovery was made that a large class of one-particle systems perturbed by a simple non-Hermitian potential term possesses a real energy spectrum. Since then regular international workshops devoted to this theme have taken place. This special issue is centred around the 6th International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics held in July 2007 at City University London. All the contributions contain significant new results or alternatively provide a survey of the state of the art of the subject or a critical assessment of the present understanding of the topic and a discussion of open problems. Original contributions from non-participants were also invited. Meanwhile many interesting results have been obtained and consensus has been reached on various central conceptual issues in the growing community of this subject. It is, for instance, well understood that the reality of the spectrum can be attributed either to the unbroken PT-symmetry of the entire system, that is, invariance of the Hamiltonian and the corresponding wavefunctions under a simultaneous parity transformation and time reversal, or more generally to its pseudo-Hermiticity . When the spectrum is real and discrete the Hamiltonian is actually quasi-Hermitian, with a positive-definite metric operator, and can in principle be related by a similarity transformation to an isospectral Hermitian counterpart. For all approaches well-defined procedures have been developed, which allow one to construct metric operators and therefore a consistent description of the underlying quantum mechanical observables. Even though the general principles have been laid out, it remains a challenge in most concrete cases to implement the entire procedure. Solvable models in this sense, some of which may be found in this issue, remain a rare exception. Nonetheless, despite this progress some important questions are still unanswered. For instance, according to the current understanding the non-Hermitian Hamiltonian does not uniquely define the physics of the system since a meaningful metric can no longer be associated with the system in a non-trivial and unambiguous manner. A fully consistent scattering theory has also not yet been formulated. Other issues remain controversial, such as the quantum brachistochrone problem, the problem of forming a mixture between a Hermitian and non-Hermitian system, the new phenomenological possibilities of forming a kind of worm-hole effect, etc. We would like to acknowledge the financial support of the London Mathematical Society, the Institute of Physics, the Doppler Institute in Prague and the School of Engineering and Mathematical Science of City University London. We hope this special issue will be useful to the newcomer as well as to the expert in the subject. Workshop photograph Participants of the 6th International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics.
NASA Astrophysics Data System (ADS)
Peng, Jia-Yin; Mo, Zhi-Wen
2013-05-01
We first provide four new schemes for two-party quantum teleportation of an arbitrary unknown multi-particle state by using three-, four-, and five-particle states as the quantum channel, respectively. The successful probability and fidelity of the four schemes reach 1. In the first two schemes, the receiver can only apply one of the unitary transformations to reconstruct the original state, making it easier for these two schemes to be directly realized. In the third and fourth schemes, the sender can preform Bell-state measurements instead of multipartite entanglement measurements of the existing similar schemes, which makes real experiments more suitable. It is found that the last three schemes may become tripartite controlled teleportation schemes of teleporting an arbitrary multi-particle state after a simple modification. Finally, we present a new scheme for three-party sharing an arbitrary unknown multi-particle state. In this scheme, the sender first shares three three-particle GHZ states with two agents. After setting up the secure quantum channel, an arbitrary unknown multi-particle state can be perfectly teleported if the sender performs three Bell-state measurements, and either of two receivers operates an appropriate unitary transformation to obtain the original state with the help of other receiver's three single-particle measurements. The successful probability and fidelity of this scheme also reach 1. It is demonstrated that this scheme can be generalized easily to the case of sharing an arbitrary unknown multi-particle state among several agents.
Quantum State Determination: Quorum for a Particle in One Dimension.
ERIC Educational Resources Information Center
Band, William; Park, James L.
1979-01-01
Explains that the quantal state describes a statistical ensemble of similar systems identically prepared, and is not to be identified with any single system. Shows how to determine empirically the general quantum state by calculations involving only the measured mean values of a set of observables called a "Quorum." (Author/GA)
Turner, M.S.
1992-05-01
Over the past year or so the research of our group has spanned many topics at the boundary of particle physics and cosmology. The major focus has been in the general areas of inflation, cosmological phase transitions, astrophysical constraints to particle physics theories, and dark matter/structure formation as it relates to particle physics. Narrative summaries of the research of the individual group members are given in this paper.
Three-particle hyper-entanglement: teleportation and quantum key distribution
NASA Astrophysics Data System (ADS)
Perumangatt, Chithrabhanu; Abdul Rahim, Aadhi; Salla, Gangi Reddy; Prabhakar, Shashi; Samanta, Goutam Kumar; Paul, Goutam; Singh, Ravindra Pratap
2015-10-01
We present a scheme to generate three-particle hyper-entanglement utilizing polarization and orbital angular momentum (OAM) of photons. We show that the generated state can be used to teleport a two-qubit state described by the polarization and the OAM. The proposed quantum system has also been used to describe a new efficient quantum key distribution (QKD) protocol. We give a sketch of the experimental arrangement to realize the proposed teleportation and the QKD.
``Who Thinks Abstractly?'': Quantum Theory and the Architecture of Physical Concepts
NASA Astrophysics Data System (ADS)
Plotnitsky, Arkady
2011-03-01
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.
'Who Thinks Abstractly?': Quantum Theory and the Architecture of Physical Concepts
Plotnitsky, Arkady
2011-03-28
Beginning with its introduction by W. Heisenberg, quantum mechanics was often seen as an overly abstract theory, mathematically and physically, vis-a-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.
Quantum Phase Coherence in Mesoscopic Transport Devices with Two-Particle Interaction
Wang, Zhimei; Guo, Xiaofang; Xue, Haibin; Xue, Naitao; Liang, J.-Q.
2015-01-01
In this paper we demonstrate a new type of quantum phase coherence (QPC), which is generated by the two-body interaction. This conclusion is based on quantum master equation analysis for the full counting statistics of electron transport through two parallel quantum-dots with antiparallel magnetic fluxes in order to eliminate the Aharonov-Bohm interference of either single-particle or non-interacting two-particle wave functions. The interacting two-particle QPC is realized by the flux-dependent oscillation of the zero-frequency cumulants including the shot noise and skewness with a characteristic period. The accurately quantized peaks of cumulant spectrum may have technical applications to probe the two-body Coulomb interaction. PMID:26255858
Efficiency of quantum energy teleportation within spin-1/2 particle pairs
NASA Astrophysics Data System (ADS)
Frey, Michael R.
2016-03-01
A protocol for quantum energy teleportation (QET) is known for a so-called minimal spin-1/2 particle pair model. We extend this protocol to explicitly admit quantum weak measurements at its first stage. The extended protocol is applied beyond the minimal model to spin-1/2 particle pairs whose Hamiltonians are of a general class characterized by orthogonal pairs of entangled eigenstates. The energy transfer efficiency of the extended QET protocol is derived for this setting, and we show that weaker measurement yields greater efficiency. In the minimal particle pair model, for example, the efficiency can be doubled by this means. We also show that the QET protocol's transfer efficiency never exceeds 100 %, supporting the understanding that quantum energy teleportation is, indeed, an energy transfer protocol, rather than a protocol for remotely catalyzing local extraction of system energy already present.
Quantum work statistics of charged Dirac particles in time-dependent fields
NASA Astrophysics Data System (ADS)
Deffner, Sebastian; Saxena, Avadh
The quantum Jarzynski equality is an important theorem of modern quantum thermodynamics. We show that the Jarzynski equality readily generalizes to relativistic quantum mechanics described by the Dirac equation. After establishing the conceptual framework we solve a pedagogical, yet experimentally relevant, system analytically. As a main result we obtain the exact quantum work distributions for charged particles traveling through a time-dependent vector potential evolving under Schrödinger as well as under Dirac dynamics, and for which the Jarzynski equality is verified. Special emphasis is put on the conceptual and technical subtleties arising from relativistic quantum mechanics. SD acknowledges financial support by the U.S. Department of Energy through a LANL Director's Funded Fellowship.
Creation of particles in a cyclic universe driven by loop quantum cosmology
NASA Astrophysics Data System (ADS)
Tavakoli, Yaser; Fabris, Júlio C.
2015-05-01
We consider an isotropic and homogeneous universe in loop quantum cosmology (LQC). We assume that the matter content of the universe is dominated by dust matter in early time and a phantom matter at late time which constitutes the dark energy component. The quantum gravity modifications to the Friedmann equation in this model indicate that the classical big bang singularity and the future big rip singularity are resolved and are replaced by quantum bounce. It turns out that the big bounce and recollapse in the herein model contribute to a cyclic scenario for the universe. We then study the quantum theory of a massive, nonminimally coupled scalar field undergoing cosmological evolution from primordial bounce towards the late time bounce. In particular, we solve the Klein-Gordon equation for the scalar field in the primordial and late time regions, in order to investigate particle production phenomena at late time. By computing the energy density of created particles at late time, we show that this density is negligible in comparison to the quantum background density at Planck era. This indicates that the effects of quantum particle production do not influence the future bounce.
ERIC Educational Resources Information Center
Ayene, Mengesha; Kriek, Jeanne; Damtie, Baylie
2011-01-01
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…
ERIC Educational Resources Information Center
Ayene, Mengesha; Kriek, Jeanne; Damtie, Baylie
2011-01-01
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
Propagation of quantum particles in Brans-Dicke spacetime: The case of gamma ray bursts
NASA Astrophysics Data System (ADS)
Capozziello, Salvatore; Lambiase, Gaetano
2015-06-01
The propagation of boson particles in a gravitational field described by the Brans-Dicke (BD) theory of gravity is analyzed. We derive the wave function of the scalar particles, and the effective potential experienced by the quantum particles considering the role of the varying gravitational coupling. Besides, we calculate the probability to find the scalar particles near the region where a naked singularity is present. The extremely high energy radiated in such a situation could account for the huge emitted power observed in gamma ray bursts (GRBs).
Modelling Systems of Classical/Quantum Identical Particles by Focusing on Algorithms
ERIC Educational Resources Information Center
Guastella, Ivan; Fazio, Claudio; Sperandeo-Mineo, Rosa Maria
2012-01-01
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…
Stochastic duality of ASEP with two particle types via symmetry of quantum groups of rank two
NASA Astrophysics Data System (ADS)
Kuan, Jeffrey
2016-03-01
We study two generalizations of the asymmetric simple exclusion process (ASEP) with two types of particles, which will be called type A 2 ASEP and type C 2 ASEP. Particles of type 1 force particles of type 2 to switch places. In the C 2 case, particles of type 2 can only influence the jump rates of particles of type 1, and in the A 2 case particles of type 2 do not influence particles of type 1 at all. We prove that the processes are self-dual and explicitly write the duality function, which is a generalization of the self-duality function for ASEP. The construction and proofs of duality are accomplished using symmetry of the quantum groups {{ U }}q({{gl}}3) and {{ U }}q({{sp}}4) for the A 2 and C 2 ASEP respectively.
FOREWORD: Corfu Summer Institute on Elementary Particle Physics (CORFU2005)
NASA Astrophysics Data System (ADS)
Anagnostopoulos, Konstantinos; Antoniadis, Ignatios; Fanourakis, George; Kehagias, Alexandros; Savoy-Navarro, Aurore; Wess, Julius; Zoupanos, George
2006-12-01
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:
[Research in theoretical and experimental elementary particle physics. Final report
1998-11-01
This report gives summaries of particle physics research conducted by different group members for Task A. A summary of work on the CLEO experiment and detector is included for Task B along with a list of CLEO publications. During the present grant period for Task C, the authors had responsibility for the design, assembly, and programming of the high-resolution spectrometer which looks for narrow peaks in the output of the cavity in the LLNL experiment. They successfully carried out this task. Velocity peaks are expected in the spectrum of dark matter axions on Earth. The computing proposal (Task S) is submitted in support of the High Energy Experiment (CLEO, Fermilab, CMS) and the Theory tasks.
Observing quantum nonlocality in the entanglement between modes of massive particles
Ashhab, S.; Maruyama, Koji
2007-02-15
We consider the question of whether it is possible to use the entanglement between spatially separated modes of massive particles to observe nonlocal quantum correlations. Mode entanglement can be obtained using a single particle, indicating that it requires careful consideration before concluding whether experimental observation--e.g., violation of Bell inequalities--is possible or not. In the simplest setups analogous to optics experiments, that observation is prohibited by fundamental conservation laws. However, we show that using auxiliary particles, mode entanglement can be converted into forms that allow the observation of quantum nonlocality. The probability of successful conversion depends on the nature and number of auxiliary particles used. In particular, we find that an auxiliary Bose-Einstein condensate allows the conversion arbitrarily many times with a small error that depends only on the initial state of the condensate.
Research Activities on MHD and Energetic Particle Physics in KSTAR
NASA Astrophysics Data System (ADS)
Park, Byoung-Ho; Kwak, Jong-Gu; Lee, San-Gon; Yoon, Si-Woo; Bae, Young-Sun; Kim, Jin-Young; KSTAR Team
2014-10-01
In this talk, the recent achievements in MHD and energetic particle physics in KSTAR will be presented. Throughout the 2014 campaign, strategically important works in achieving KSTAR milestone including NTM stabilization, error field measurement, establishing disruption mitigation system, and identification of Alfvenic eigenmode are conducted. Real time feedback control of 2/1 NTM is successfully demonstrated with the search and suppression algorithm and the improved ECCD mirror control system. 3-D structure of n=1 intrinsic error field are fully explored with L- and H-mode plasma aiming not only to complete MID IVCC compass scan but also to set a groundwork toward understanding of KSTAR's unique feature, ELM suppression by n = 1 RMP. Elaborated q95 ~ 2 discharge regime is achieved without any error field correction by virtue of the extremely low intrinsic error field of KSTAR. The integrated disruption avoidance/mitigation system for the safety secured MA-class operation is well assessed. Further investigations of the energetic particle mode have been done with various control nobs of ECH, RMP and tailoring of NBI profile and mode identification efforts have been followed. Besides high priority works above, studies on sawtooth and run-away electron have made progresses.