On the particle-vibration multiplets
International Nuclear Information System (INIS)
Khodel, V.A.; Platonov, A.P.; Saperstein, E.E.
1980-01-01
The particle-vibration multiplet spectra in the lead region are calculated in the framework of the self-consistent theory of finite Fermi systems. The calculated results are compared with the experimental data and with the results of other authors. (author)
Particle-core multiplets in 89Y
International Nuclear Information System (INIS)
Batsch, T.; Kownacki, J.; Zelazny, Z.; Guttormsen, M.; Ramsoey, T.; Rekstad, J.
1987-10-01
The 89 Y nucleus has been formed in its excited states via the 87 Rb(α,2n) reaction at incident energies 24-34 MeV. The γ-ray decay of the states has been studied by measuring γ-γ-t coincidences, angular distributions and relative excitation functions. The experimental results from the present investigation are in general agreement with the former studies. However, some corrections in the level scheme have been introduced. Eight new levels with spins up to around 31/2 ℎ have been observed. The uppermost levels have been arranged into a rotational-like sequence, suggesting a nuclear shape change. Using our and previously known data we have tried to locate and calculate the members of the 1g 9/2 x core multiplet. The present results are compared with the semi-empirical shell model and the particle-core weak coupling description
Nambu, Y.
1967-01-01
The main ingredients of the method of infinite multiplets consist of: 1) the use of wave functions with an infinite number of components for describing an infinite tower of discrete states of an isolated system (such as an atom, a nucleus, or a hadron), 2) the use of group theory, instead of dynamical considerations, in determining the properties of the wave functions.
Directory of Open Access Journals (Sweden)
Colò Gianluca
2016-01-01
Full Text Available In this contribution, we shall describe a formalism that goes beyond the simple time-dependent mean field and is based on particle-vibration coupling (PVC. Such a formalism has been developed with the idea of being self-consistent. It makes use of Skyrme effective forces, and has been used for several applications. We will focus on charge-exchange transitions, namely we will show that our model describes well both the Gamow-Teller giant resonance width, and the low-lying transitions associated with β-decay. In this latter case, including PVC produces a significant improvement of the half-lives obtained at mean-field level, and leads to a good agreement with experimental data. We will end by discussing particle-phonon multiplets in odd nuclei.
Density scaling for multiplets
International Nuclear Information System (INIS)
Nagy, A
2011-01-01
Generalized Kohn-Sham equations are presented for lowest-lying multiplets. The way of treating non-integer particle numbers is coupled with an earlier method of the author. The fundamental quantity of the theory is the subspace density. The Kohn-Sham equations are similar to the conventional Kohn-Sham equations. The difference is that the subspace density is used instead of the density and the Kohn-Sham potential is different for different subspaces. The exchange-correlation functional is studied using density scaling. It is shown that there exists a value of the scaling factor ζ for which the correlation energy disappears. Generalized OPM and Krieger-Li-Iafrate (KLI) methods incorporating correlation are presented. The ζKLI method, being as simple as the original KLI method, is proposed for multiplets.
Superconformal current multiplet
International Nuclear Information System (INIS)
Smailagic, A.
1982-12-01
We consider a derivation of a superconformal current multiplet based directly on superconformal algebra. This gives usual multiplet of currents without anomalies, directly in terms of ''improved'' quantities and without reference to a particular Lagrangian model. (author)
Eden, Burkhard; Korchemsky, Gregory P; Sokatchev, Emery
2012-01-01
We present a construction of the integrand of the correlation function of four stress-tensor multiplets in N=4 SYM at weak coupling. It does not rely on Feynman diagrams and makes use of the recently discovered symmetry of the integrand under permutations of external and integration points. This symmetry holds for any gauge group, so it can be used to predict the integrand both in the planar and non-planar sectors. We demonstrate the great efficiency of graph-theoretical tools in the systematic study of the possible permutation symmetric integrands. We formulate a general ansatz for the correlation function as a linear combination of all relevant graph topologies, with arbitrary coefficients. Powerful restrictions on the coefficients come from the analysis of the logarithmic divergences of the correlation function in two singular regimes: Euclidean short-distance and Minkowski light-cone limits. We demonstrate that the planar integrand is completely fixed by the procedure up to six loops and probably beyond. ...
Nonabelian generalized gauge multiplets
International Nuclear Information System (INIS)
Lindstroem, Ulf; Zabzine, Maxim; Rocek, Martin; Ryb, Itai; Unge, Rikard von
2009-01-01
We give the nonabelian extension of the newly discovered N = (2, 2) two-dimensional vector multiplets. These can be used to gauge symmetries of sigma models on generalized Kaehler geometries. Starting from the transformation rule for the nonabelian case we find covariant derivatives and gauge covariant field-strengths and write their actions in N = (2, 2) and N = (1, 1) superspace.
International Nuclear Information System (INIS)
Wit, B. de; Rocek, M.
1982-01-01
We construct a conformally invariant theory of the N = 1 supersymmetric tensor gauge multiplet and discuss the situation in N = 2. We show that our results give rise to the recently proposed variant of Poincare supergravity, and provide the complete tensor calculus for the theory. Finally, we argue that this theory cannot be quantized sensibly. (orig.)
International Nuclear Information System (INIS)
Cornagliotto, Martina; Lemos, Madalena; Schomerus, Volker
2017-02-01
Applications of the bootstrap program to superconformal field theories promise unique new insights into their landscape and could even lead to the discovery of new models. Most existing results of the superconformal bootstrap were obtained form correlation functions of very special fields in short (BPS) representations of the superconformal algebra. Our main goal is to initiate a superconformal bootstrap for long multiplets, one that exploits all constraints from superprimaries and their descendants. To this end, we work out the Casimir equations for four-point correlators of long multiplets of the two-dimensional global N=2 superconformal algebra. After constructing the full set of conformal blocks we discuss two different applications. The first one concerns two-dimensional (2,0) theories. The numerical bootstrap analysis we perform serves a twofold purpose, as a feasibility study of our long multiplet bootstrap and also as an exploration of (2,0) theories. A second line of applications is directed towards four-dimensional N=3 SCFTs. In this context, our results imply a new bound c ≥ (13)/(24) for the central charge of such models. A theory that saturates this bound is not known yet.
Energy Technology Data Exchange (ETDEWEB)
Cornagliotto, Martina; Lemos, Madalena; Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group
2017-02-15
Applications of the bootstrap program to superconformal field theories promise unique new insights into their landscape and could even lead to the discovery of new models. Most existing results of the superconformal bootstrap were obtained form correlation functions of very special fields in short (BPS) representations of the superconformal algebra. Our main goal is to initiate a superconformal bootstrap for long multiplets, one that exploits all constraints from superprimaries and their descendants. To this end, we work out the Casimir equations for four-point correlators of long multiplets of the two-dimensional global N=2 superconformal algebra. After constructing the full set of conformal blocks we discuss two different applications. The first one concerns two-dimensional (2,0) theories. The numerical bootstrap analysis we perform serves a twofold purpose, as a feasibility study of our long multiplet bootstrap and also as an exploration of (2,0) theories. A second line of applications is directed towards four-dimensional N=3 SCFTs. In this context, our results imply a new bound c ≥ (13)/(24) for the central charge of such models. A theory that saturates this bound is not known yet.
Cornagliotto, Martina; Lemos, Madalena; Schomerus, Volker
2017-10-01
Applications of the bootstrap program to superconformal field theories promise unique new insights into their landscape and could even lead to the discovery of new models. Most existing results of the superconformal bootstrap were obtained form correlation functions of very special fields in short (BPS) representations of the superconformal algebra. Our main goal is to initiate a superconformal bootstrap for long multiplets, one that exploits all constraints from superprimaries and their descendants. To this end, we work out the Casimir equations for four-point correlators of long multiplets of the two-dimensional global N=2 superconformal algebra. After constructing the full set of conformal blocks we discuss two different applications. The first one concerns two-dimensional (2,0) theories. The numerical bootstrap analysis we perform serves a twofold purpose, as a feasibility study of our long multiplet bootstrap and also as an exploration of (2,0) theories. A second line of applications is directed towards four-dimensional N=3 SCFTs. In this context, our results imply a new bound c≥ 13/24 for the central charge of such models, which we argue cannot be saturated by an interacting SCFT.
Multiplet mass splitting in a gravitational field
International Nuclear Information System (INIS)
Maia, M.D.
An expression for the mass splitting of particles belonging to the same spin multiplet defined in a space-time of general relativity is derived. The geometrical symmetry is a subgroup of SO(r,s), 9 >=r > 3, 5 >=s >=1, the mass operator being proportional to the second order Casimir operator of that subgroup. A brief analysis of the calculated values as compared to the experimental data is included. (Author) [pt
The Large Vector Multiplet Action
Ryb, Itai
2007-01-01
We discuss possible actions for the d=2, N=(2,2) large vector multiplet that gauges isometries of generalized Kahler geometries. We explore two scenarios that allow us to write kinetic and superpotential terms for the scalar field-strengths, and write kinetic terms for the spinor invariants that can introduce topological terms for the connections.
Neutrino mass with large S U (2 )L multiplet fields
Nomura, Takaaki; Okada, Hiroshi
2017-11-01
We propose an extension of the standard model introducing large S U (2 )L multiplet fields which are quartet and septet scalars and quintet Majorana fermions. These multiplets can induce the neutrino masses via interactions with the S U (2 ) doublet leptons. We then find the neutrino masses are suppressed by a small vacuum expectation value of the quartet/septet and an inverse of the quintet fermion mass, relaxing the Yukawa hierarchies among the standard model fermions. We also discuss collider physics at the Large Hadron Collider, considering the production of charged particles in these multiplets, and due to the effects of violating the custodial symmetry, some specific signatures can be found. Then, we discuss the detectability of these signals.
Unconstrained multiplet in N=2 conformal supergravity
International Nuclear Information System (INIS)
Hayashi, Masahito; Uehara, Shozo.
1985-02-01
An unconstrained (general) multiplet was studied in N = 2 conformal supergravity. Transformation law, embedding formula and multiplication rule are explicitly presented at the linearized level. (author)
Transfusion syndromes in monochorionic multiplets: An overview
African Journals Online (AJOL)
come for attention to be focused on an area of gemellology, feto‑fetal transfusion syndromes in multiplets, in order ... These health hazards, all causes of very high perinatal ..... of monochorionic twin pregnancy complicated with selective fetal.
(2, 0) tensor multiplets and conformal supergravity in D = 6
Bergshoeff, Eric; Sezgin, Ergin; Proeyen, Antoine Van
1999-01-01
We construct the supercurrent multiplet that contains the energyâ€“momentum tensor of the (2, 0) tensor multiplet. By coupling this multiplet of currents to the fields of conformal supergravity, we first construct the linearized superconformal transformations rules of the (2, 0) Weyl multiplet.
Mass differences between fondamental baryon multiplets
International Nuclear Information System (INIS)
Casanova, Gaston.
1976-01-01
Using the relativist equations of the nucleon, of the Ψ doublet and the Σ-triplet, that generalize the Dirac equation, and assuming that virtual K-mesons act on the hyperons, it is possible to evaluate the mass differences between multiplets whose electromagnetic origin is confirmed [fr
Tensor calculus for the vector multiplet coupled to supergravity
International Nuclear Information System (INIS)
Stelle, K.S.
1978-01-01
An invariant coupling of a local vector multiplet to supergravity is constructed in analogy with the D term invariant of global supersymmetry. The rules for combining local vector and chiral scalar multiplets of opposite chirality are given. (Auth.)
Superspace actions and duality transformations for N=2 tensor multiplets
International Nuclear Information System (INIS)
Galperin, A.; Ivanov, E.; Ogievetsky, V.
1985-01-01
General actions for self-interacting N=2 tensor multiplets are considered in the harmonic superspace approach. All of them are shown to be equivalent, by superfield duality transformations, to some restricted class of the hypermultiplets actions. In particular, the improved tensor multiplet theory is dual to a free hypermultiplet one. Superspace couplings of these improved matter multiplets against conformal supergravity are also constructed
Couplings of self-dual tensor multiplet in six dimensions
Bergshoeff, E.; Sezgin, E.; Sokatchev, E.
1996-01-01
The (1, 0) supersymmetry in six dimensions admits a tensor multiplet which contains a second-rank antisymmetric tensor field with a self-dual field strength and a dilaton. We describe the fully supersymmetric coupling of this multiplet to a Yangâ€“Mills multiplet, in the absence of supergravity. The
Microseismic multiplets in the northeastern Bohemian Massif
Czech Academy of Sciences Publication Activity Database
Špaček, Petr; Zacherle, P.; Sýkorová, Z.; Pazdírková, J.
2011-01-01
Roč. 39, č. 5-6 (2011), s. 367-386 ISSN 0303-4534 R&D Projects: GA ČR GA205/09/1170; GA MŠk LM2010008 Institutional research plan: CEZ:AV0Z30120515 Keywords : microseismicity * seismic multiplets * Sudetic Fault System * correlation * active tectonics * pull-apart Subject RIV: DC - Siesmology, Volcanology, Earth Structure
The anomalous current multiplet in 6D minimal supersymmetry
Energy Technology Data Exchange (ETDEWEB)
Kuzenko, Sergei M. [School of Physics M013, The University of Western Australia,35 Stirling Highway, Crawley, W.A. 6009 (Australia); Novak, Joseph [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,Am Mühlenberg 1, D-14476 Golm (Germany); Samsonov, Igor B. [School of Physics M013, The University of Western Australia,35 Stirling Highway, Crawley, W.A. 6009 (Australia)
2016-02-19
For supersymmetric gauge theories with eight supercharges in four, five and six dimensions, a conserved current belongs to the linear multiplet. In the case of six-dimensional N=(1,0) Poincaré supersymmetry, we present a consistent deformation of the linear multiplet which describes chiral anomalies. This is achieved by developing a superform formulation for the deformed linear multiplet. In the abelian case, we compute a nonlocal effective action generating the gauge anomaly.
Self-organized vortex multiplets in swirling flow
DEFF Research Database (Denmark)
Okulov, Valery; Naumov, Igor; Sørensen, Jens Nørkær
2008-01-01
The possibility of double vortex multiplet formation at the center of an intensively swirling cocurrent flow generated in a cylindrical container by its rotating lid is reported for the first time. The boundary of the transition to unsteady flow regimes, which arise as a result of the equilibrium...... rotation of self-organized vortex multiplets (triplet, double triplet, double doublet, and quadruplet), has been experimentally determined for cylinders with the aspect (height to radius) ratios in a wider interval than that studied previously....
Off-shell superconformal higher spin multiplets in four dimensions
Kuzenko, Sergei M.; Manvelyan, Ruben; Theisen, Stefan
2017-07-01
We formulate off-shell N = 1 superconformal higher spin multiplets in four spacetime dimensions and briefly discuss their coupling to conformal supergravity. As an example, we explicitly work out the coupling of the superconformal gravitino multiplet to conformal supergravity. The corresponding action is super-Weyl invariant for arbitrary supergravity backgrounds. However, it is gauge invariant only if the supersymmetric Bach tensor vanishes. This is similar to linearised conformal supergravity in curved background.
U-duality multiplets and nonperturbative superstring states
International Nuclear Information System (INIS)
Bars, I.; Yankielowicz, S.
1996-01-01
We employ an algebraic approach for unifying perturbative and nonperturbative superstring states on an equal footing, in the form of U-duality multiplets, at all excited string levels. In compactified type-IIA supertring theory we present evidence that the multiplet is labeled by two spaces, open-quote open-quote index close-quote close-quote space and open-quote open-quote base close-quote close-quote space, on which U acts without mixing them. Both spaces are nonperturbative extensions of similar spaces that label perturbative T-duality multiplets. Base space consists of all the central charges of the 11D SUSY algebra, while index space corresponds to representations of the maximal compact subgroup K improper-subset U. This structure predicts the quantum numbers of the nonperturbative states. We also discuss whether and how U multiplets may coexist with 11-dimensional multiplets that are associated with an additional nonperturbative 11D structure that seems to be lurking behind in the underlying theory. copyright 1996 The American Physical Society
24 +24 real scalar multiplet in four dimensional N =2 conformal supergravity
Hegde, Subramanya; Lodato, Ivano; Sahoo, Bindusar
2018-03-01
Starting from the 48 +48 component multiplet of supercurrents for a rigid N =2 tensor multiplet in four spacetime dimensions, we obtain the transformation of the linearized supergravity multiplet which couples to this supercurrent multiplet. At the linearized level, this 48 +48 component supergravity multiplet decouples into the 24 +24 component linearized standard Weyl multiplet and a 24 +24 component irreducible matter multiplet containing a real scalar field. By a consistent application of the supersymmetry algebra with field-dependent structure constants appropriate to N =2 conformal supergravity, we find the full transformation law for this multiplet in a conformal supergravity background. By performing a suitable field redefinition, we find that the multiplet is a generalization of the flat space multiplet, obtained by Howe et al. in Nucl. Phys. B214, 519 (1983), 10.1016/0550-3213(83)90249-3, to a conformal supergravity background. We also present a set of constraints which can be consistently imposed on this multiplet to obtain a restricted minimal 8 +8 off-shell matter multiplet. We also show, as an example, the precise embedding of the tensor multiplet inside this multiplet.
The spin (3/2,1) multiplet and superspace geometry
International Nuclear Information System (INIS)
Gates, S.J. Jr.; Grimm, R.
1985-01-01
We give a completely geometrical derivation of the de Wit-van Holten formulation of a supermultiplet with physical helicity states one and three-halves. We identify all of the components of the multiplet, derive the transformation laws, and construct an invariant action. Like supergravity the action is not expressible only in terms of field strengths. (orig.)
Supersymmetric vector multiplets in nonadjoint representations of SO(N)
International Nuclear Information System (INIS)
Nishino, Hitoshi; Rajpoot, Subhash
2007-01-01
In the conventional formulation of N=1 supersymmetry, a vector multiplet is supposed to be in the adjoint representation of a given gauge group. We present a new formulation with a vector multiplet in the nonadjoint representation of SO(N) gauge group. Our basic algebra is [T I ,T J ]=f IJK T K , [T I ,U i ]=-(T I ) ij U j , [U i ,U j ]=-(T I ) ij T I , where T I are the generators of SO(N), while U i are the new ''generators'' in certain nonadjoint real representation R of SO(N). We use here the word generator in the broader sense of the word. Such a representation can be any real representation of SO(N) with the positive definite metric, satisfying (T I ) ij =-(T I ) ji and (T I ) [ij| (T I ) |k]l ≡0. The first nontrivial examples are the spinorial 8 S and conjugate spinorial 8 C representations of SO(8) consistent with supersymmetry. We further couple the system to chiral multiplets and show that a Higgs mechanism can give positive definite (mass) 2 to the new gauge fields for U i . We show an analogous system working with N=1 supersymmetry in 10D, and thereby N=4 system in 4D interacting with extra multiplets in the representation R. We also perform superspace reformulation as an independent confirmation
Off-shell N=2 linear multiplets in five dimensions
Energy Technology Data Exchange (ETDEWEB)
Ozkan, Mehmet [Department of Physics, Istanbul Technical University,Maslak 34469 Istanbul (Turkey)
2016-11-25
We present a superconformal tensor calculus for an arbitrary number of five dimensional N=2 linear multiplets. We also demonstrate how to construct higher derivative invariants, and produce higher order supersymmetric off-diagonal models. Finally, we show the procedure required for the derivation of the supersymmetric completion of the non-Abelian F{sup 4} action.
The nature of the neutrino as the compound structure of the multiplet
International Nuclear Information System (INIS)
Sharafiddinov, R.S.
2003-01-01
In this work an explicit form of the differential cross sections describing the elastic scattering of unpolarized and longitudinal polarized neutrinos and electrons on spinless nuclei as a consequence of the availability of normal rest mass, electric charge and magnetic moment of elementary particles have been established. With the use of the proposed formulas as well as the united equation between charge and magnetic form factors of light leptons are obtained. The second of them correspond in the nature to the particles doublet. According to their solutions, the properties of the neutrino and electron one must consider as the compound structure of the multiplet. Such a regularity, however, meets with many problems which give the possibility to directly look at the nature of elementary particles
Dual multiplets in N=4 superconformal mechanics
Bellucci, Stefano; Sutulin, Anton
2013-01-01
We propose Lagrangian formulations of a three-particles translation invariant $N=4$ superconformal mechanics based on the standard and twisted $(1,4,3)$ supermultiplets. We show that in the appropriate set of coordinates, in which the bosonic kinetic terms for each of the two cases take conformally-flat forms, the corresponding models produce just similar physical systems with the flipped angular part of bosonic potential $U(x)\\rightarrow 1/U(x)$. This flipping looks so simple only being written in the ``angle'' variable, while in the standard variables it looks more complicated to preserve the superconformal symmetry. We demonstrate at both the superfield and the component level, how familiar $N=4$ supersymmetric 3-particles models, including $3-Calogero$, ${\\it BC_2}$ and ${\\it G_2}$ ones, can be constructed with twisted supermultiplets. We also present some new explicit examples of 3-dimensional superconformal mechanics.
The isobaric multiplet mass equation for A≤71 revisited
Energy Technology Data Exchange (ETDEWEB)
Lam, Yi Hua, E-mail: lamyihua@gmail.com [CENBG (UMR 5797 — Université Bordeaux 1 — CNRS/IN2P3), Chemin du Solarium, Le Haut Vigneau, BP 120, 33175 Gradignan Cedex (France); Blank, Bertram, E-mail: blank@cenbg.in2p3.fr [CENBG (UMR 5797 — Université Bordeaux 1 — CNRS/IN2P3), Chemin du Solarium, Le Haut Vigneau, BP 120, 33175 Gradignan Cedex (France); Smirnova, Nadezda A. [CENBG (UMR 5797 — Université Bordeaux 1 — CNRS/IN2P3), Chemin du Solarium, Le Haut Vigneau, BP 120, 33175 Gradignan Cedex (France); Bueb, Jean Bernard; Antony, Maria Susai [IPHC, Université de Strasbourg, CNRS/UMR7178, 23 Rue du Loess, 67037 Strasbourg Cedex (France)
2013-11-15
Accurate mass determination of short-lived nuclides by Penning-trap spectrometers and progress in the spectroscopy of proton-rich nuclei have triggered renewed interest in the isobaric multiplet mass equation (IMME). The energy levels of the members of T=1/2,1,3/2, and 2 multiplets and the coefficients of the IMME are tabulated for A≤71. The new compilation is based on the most recent mass evaluation (AME2011) and it includes the experimental results on energies of the states evaluated up to end of 2011. Taking into account the error bars, a significant deviation from the quadratic form of the IMME for the A=9,35 quartets and the A=32 quintet is observed.
The simple method of determination peaks areas in multiplets
International Nuclear Information System (INIS)
Loska, L.; Ptasinski, J.
1991-01-01
Semiconductor germanium detectors used in γ-spectrometry give spectra with well-separated peaks. However, in some cases, energies of γ-lines are too near, to produce resolved and undisturbed peaks. Then, there is a necessity to perform a mathematical separation. The method proposed here is based on the assumption, that areas of peaks composing the analysed multiplet are proportional to their heights. The method can be applied for any number of interfering peaks, providing, that the function of the background under the multiplet is accurately determined. The results of testing calculations performed on a simulated spectrum are given. The method works successfully in a computer program used for neutron activation analysis data processing. (author). 9 refs, 1 fig, 1 tab
International Nuclear Information System (INIS)
Scherer, S.; Bleicher, M.; Haussler, S.; Stoecker, H.
2008-01-01
The recent discussion about experimental evidence for pentaquark states has revitalized the interest in exotic hadrons. If such states really exist, it is natural to assume that they will be formed at the late hadronization stage of ultra-relativistic heavy ion collisions, given the success of quark recombination models in the description of hadronization. Here, we apply the qMD model to study the formation of color neutral exotic multi-quark clusters at hadronization. We search for color neutral clusters made up of up to six color charges, respectively. We thus obtain estimates for the numbers and phase space distributions of exotic hadronic states produced by clustering in heavy ion collisions, including the members of the pentaquark multiplets. We obtain particle abundances that are smaller than thermal model predictions. Moreover, the results obtained in recombination from ultra-relativistic heavy ion collisions can be compared to the estimates based on equal population of the corresponding multiplets, and to results from fully thermalized systems. We find that the distribution of exotic hadrons from recombination over large multiplets provides a sensitive signal for thermalization and decorrelation of the initial, non-equilibrium state of the collision. (author)
Multiplets: Their behavior and utility at dacitic and andesitic volcanic centers
Thelen, W.; Malone, S.; West, M.
2011-01-01
Multiplets, or groups of earthquakes with similar waveforms, are commonly observed at volcanoes, particularly those exhibiting unrest. Using triggered seismic data from the 1980-1986 Mount St. Helens (MSH) eruption, we have constructed a catalog of multiplet occurrence. Our analysis reveals that the occurrence of multiplets is related, at least in part, to the viscosity of the magma. We also constructed catalogs of multiplet occurrence using continuous seismic data from the 2004 eruption at MSH and 2007 eruption at Bezymianny Volcano, Russia. Prior to explosions at MSH in 2004 and Bezymianny in 2007, the multiplet proportion of total seismicity (MPTS) declined, while the average amplitudes and standard deviations of the average amplitude increased. The life spans of multiplets (time between the first and last event) were also shorter prior to explosions than during passive lava extrusion. Dome-forming eruptions that include a partially solidified plug, like MSH (1983-1986 and 2004-2008), often possess multiplets with longer life spans and MPTS values exceeding 50%. Conceptually, the relatively unstable environment prior to explosions is characterized by large and variable stress gradients brought about by rapidly changing overpressures within the conduit. We infer that such complex stress fields affect the number of concurrent families, MPTS, average amplitude, and standard deviation of the amplitude of the multiplets. We also argue that multiplet detection may be an important new monitoring tool for determining the timing of explosions and in forecasting the type of eruption.
Betti multiplets, flows across dimensions and c-extremization
Amariti, Antonio; Toldo, Chiara
2017-07-01
We consider 4d N = 1 SCFTs, topologically twisted on compact constant curvature Riemann surfaces, giving rise to 2d N = (0, 2) SCFTs. The exact R-current of these 2d SCFT extremizes the central charge c 2 d , similarly to the 4d picture, where the exact R-current maximizes the central charge a 4 d . There are global currents that do not mix with the R-current in 4d but their mixing becomes non trivial in 2d. In this paper we study the holographic dual of this process by analyzing a 5d N = 2 truncation of T 1,1 with one Betti vector multiplet, dual to the baryonic current on the CFT side. The holographic realization of the flow across dimensions connects AdS5 to AdS3 vacua in the supergravity picture. We verify the existence of the flow to AdS3 solutions and we retrieve the field theory results for the mixing of the Betti vector with the graviphoton. Moreover, we extract the central charge from the Brown-Henneaux formula, matching with the results obtained in field theory. We develop a general formalism to obtain the central charge of a 2d SCFT from 5d N = 2 gauged supergravity with a generic number of vector multiplets, showing that its extremization corresponds to an attractor mechanism for the scalars in the supergravity picture.
Optimisation of multiplet identifier processing on a PLAYSTATION® 3
Hattori, Masami; Mizuno, Takashi
2010-02-01
To enable high-performance computing (HPC) for applications with large datasets using a Sony® PLAYSTATION® 3 (PS3™) video game console, we configured a hybrid system consisting of a Windows® PC and a PS3™. To validate this system, we implemented the real-time multiplet identifier (RTMI) application, which identifies multiplets of microearthquakes in terms of the similarity of their waveforms. The cross-correlation computation, which is a core algorithm of the RTMI application, was optimised for the PS3™ platform, while the rest of the computation, including data input and output remained on the PC. With this configuration, the core part of the algorithm ran 69 times faster than the original program, accelerating total computation speed more than five times. As a result, the system processed up to 2100 total microseismic events, whereas the original implementation had a limit of 400 events. These results indicate that this system enables high-performance computing for large datasets using the PS3™, as long as data transfer time is negligible compared with computation time.
Lossless Image Compression Based on Multiple-Tables Arithmetic Coding
Directory of Open Access Journals (Sweden)
Rung-Ching Chen
2009-01-01
Full Text Available This paper is intended to present a lossless image compression method based on multiple-tables arithmetic coding (MTAC method to encode a gray-level image f. First, the MTAC method employs a median edge detector (MED to reduce the entropy rate of f. The gray levels of two adjacent pixels in an image are usually similar. A base-switching transformation approach is then used to reduce the spatial redundancy of the image. The gray levels of some pixels in an image are more common than those of others. Finally, the arithmetic encoding method is applied to reduce the coding redundancy of the image. To promote high performance of the arithmetic encoding method, the MTAC method first classifies the data and then encodes each cluster of data using a distinct code table. The experimental results show that, in most cases, the MTAC method provides a higher efficiency in use of storage space than the lossless JPEG2000 does.
International Nuclear Information System (INIS)
Gupta, Rajesh Kumar; Ito, Yuto; Jeon, Imtak
2015-01-01
We use the techniques of supersymmetric localization to compute the BPS black hole entropy in N=2 supergravity. We focus on the n_v+1 vector multiplets on the black hole near horizon background which is AdS_2× S"2 space. We find the localizing saddle point of the vector multiplets by solving the localization equations, and compute the exact one-loop partition function on the saddle point. Furthermore, we propose the appropriate functional integration measure. Through this measure, the one-loop determinant is written in terms of the radius of the physical metric, which depends on the localizing saddle point value of the vector multiplets. The result for the one-loop determinant is consistent with the logarithmic corrections to the BPS black hole entropy from vector multiplets.
Two-loop mass splittings in electroweak multiplets: Winos and minimal dark matter
McKay, James; Scott, Pat
2018-03-01
The radiatively-induced splitting of masses in electroweak multiplets is relevant for both collider phenomenology and dark matter. Precision two-loop corrections of O (MeV ) to the triplet mass splitting in the wino limit of the minimal supersymmetric standard model can affect particle lifetimes by up to 40%. We improve on previous two-loop self-energy calculations for the wino model by obtaining consistent input parameters to the calculation via two-loop renormalization-group running, and including the effect of finite light quark masses. We also present the first two-loop calculation of the mass splitting in an electroweak fermionic quintuplet, corresponding to the viable form of minimal dark matter (MDM). We place significant constraints on the lifetimes of the charged and doubly-charged fermions in this model. We find that the two-loop mass splittings in the MDM quintuplet are not constant in the large-mass limit, as might naively be expected from the triplet calculation. This is due to the influence of the additional heavy fermions in loop corrections to the gauge boson propagators.
N = 4 Superconformal Chern-Simons theories with hyper and twisted hyper multiplets
International Nuclear Information System (INIS)
Hosomichi, Kazuo; Lee, Ki-Myeong; Lee, Sungjay; Lee, Sangmin; Park, Jaemo
2008-01-01
We extend the N = 4 superconformal Chern-Simons theories of Gaiotto and Witten to those with additional twisted hyper-multiplets. The new theories are generically linear quiver gauge theories with the two types of hyper-multiplets alternating between gauge groups. Our construction includes the Bagger-Lambert model of SO(4) gauge group. A family of abelian theories are identified with those proposed earlier in the context of the M-crystal model for M2-branes probing (C 2 /Z n ) 2 orbifolds. Possible extension with non-abelian BF couplings and string/M-theory realization are briefly discussed.
The Sommerfeld enhancement in the scotogenic model with large electroweak scalar multiplets
Energy Technology Data Exchange (ETDEWEB)
Chowdhury, Talal Ahmed [Department of Physics, University of Dhaka, P.O. Box 1000, Dhaka (Bangladesh); Nasri, Salah, E-mail: talal@du.ac.bd, E-mail: snasri@uaeu.ac.ae [Department of Physics, UAE University, P.O. Box 17551, Al-Ain (United Arab Emirates)
2017-01-01
We investigate the Sommerfeld enhancement (SE) in the generalized scotogenic model with large electroweak multiplets. We focus on scalar dark matter (DM) candidate of the model and compare DM annihilation cross sections to WW , ZZ , γγ and γ Z at present day in the galactic halo for scalar doublet and its immediate generalization, the quartet in their respective viable regions of parameter space. We find that larger multiplet has sizable Sommerfeld enhanced annihilation cross section compared to the doublet and because of that it is more likely to be constrained by the current H.E.S.S. results and future CTA sensitivity limits.
Dual vector multiplet coupled to dual N=1 supergravity in 10D
International Nuclear Information System (INIS)
Nishino, Hitoshi; Rajpoot, Subhash
2005-01-01
We couple in superspace a dual vector multiplet (C m 1 ...m 7 ,λ α ) to the dual version of N=1 supergravity (e m a ,ψ m α ,M m 1 ...m 6 ,χ α ,Φ) in ten dimensions. The 7-form field C has its 8-form field strength H dual to the 2-form field strength F of the conventional vector multiplet. To simplify the computation, we use so-called beta-function-favored superspace constraints for dual supergravity developed for β-function computations. As in a more conventional constraint set, the H-Bianchi identity must have the form N and F, where N is the 7-form field strength in dual supergravity. The potential anomaly for the dual vector multiplet can be cancelled for the particular gauge group U(1) 496 by the Green-Schwarz mechanism. As a by-product, we also give the globally supersymmetric Abelian Dirac-Born-Infeld interactions for the dual vector multiplet for the first time
Reducing condition number by appropriate current decomposition on a multiplet of several wires
CSIR Research Space (South Africa)
Lysko, AA
2011-07-01
Full Text Available This paper discusses a numerical investigation in connection with the dependency of the condition number of the impedance matrix on the decomposition of current on a junction with several attached wires (multiplet). It is shown that the condition...
Multiplet splitting of x-ray photoemission spectra core levels in magnetic metals
International Nuclear Information System (INIS)
Kowalczyk, S.P.; McFeely, F.R.; Ley, L.; Shirley, D.A.
1975-01-01
The results of high resolution x-ray photoemission studies of the multiplet splitting of the 3s core levels in the 3d transition metals and the 4s, 5s and 4d core levels in the lanthanide metals are reported
SALOME. Software for the analysis of lines or multiplets from Extrap. User's guide
International Nuclear Information System (INIS)
Zastrow, K.D.
1994-01-01
This user's guide describes the centre piece of spectral analysis programs for Extrap-T1. The method for spectral analysis is presented theoretically. It also presents the actual use of the program PROBESCHUSS and how to work on the multiplet library. The present user's guide is about PROBESCHUSS 2.1 and MULTIFIT 2.0. 7 figs, 5 appendices
Study of multiplet structures of Mn4+ activated in fluoride crystals
International Nuclear Information System (INIS)
Novita, Mega; Honma, Tetsuo; Hong, Byungchul; Ohishi, Atsushi; Ogasawara, Kazuyoshi
2016-01-01
We investigated the optical properties of Mn 4+ in some fluoride crystals such as Cs 2 MnF 6 , Cs 2 GeF 6 , Rb 2 GeF 6 , Cs 2 SiF 6 , K 2 SiF 6 , Rb 2 MnF 6 , Rb 2 SiF 6 , K 2 GeF 6 , K 2 TiF 6 , Li 2 MnF 6 , Na 2 GeF 6 , Na 2 SiF 6 , and Na 2 TiF 6 based on the first-principle calculation using the discrete-variational multi-electron method. In order to estimate the lattice relaxation, we performed EXAFS measurement of Mn 4+ doped in K 2 SiF 6 , K 2 TiF 6 , and K 2 GeF 6 . The relaxation rates of A 2 BF 6 :Mn 4+ were fixed to be the above estimated values, 102.24%, 107.37% or 96.80% for crystal having Si, Ge, or Ti at the B cation site, respectively. In this work, we also considered some corrections such as configuration dependent correction and correlation correction to improve the theoretical energies. It has been shown that to reproduce multiplet energy levels quantitatively, the lattice relaxation is very important. On the other hand, for a qualitative prediction of the tendencies of the multiplet energies, the combination of lattice relaxation effect, configuration dependent correction, and correlation correction is effective. - Highlights: • Multiplet structures of A 2 BF 6 :Mn 4+ were calculated from first-principles. • Lattice relaxation was estimated based on EXAFS experiment. • Lattice relaxation is important to reproduce multiplet energies quantitatively. • CDC and CC are important to reproduce tendencies of multiplet energies.
Diversity of off-shell twisted (4,4) multiplets in SU(2)xSU(2) harmonic superspace
International Nuclear Information System (INIS)
Ivanov, E.A.; Sutulin, A.O.
2004-01-01
We elaborate on four different types of twisted N=(4,4) supermultiplets in the SU(2)xSU(2), 2D harmonic superspace. In the conventional N=(4,4), 2D superspace they are described by the superfields q ia , q Ia , q IA , subjected to proper differential constraints, (i, I, a, A) being the doublet indices of four groups SU(2) which form the full R-symmetry group SO(4) L xSO(4) R of N=(4,4) supersymmetry. We construct the torsionful off-shell sigma-model actions for each type of these multiplets, as well as the corresponding invariant mass terms, in an analytic subspace of the SU(2)xSU(2) harmonic superspace. As an instructive example, N=(4,4) superconformal extension of the SU(2)xU(1) WZNW sigma-model action and its massive deformation are presented for the multiplet q iA . We prove that N=(4,4) supersymmetry requires the general sigma-model action of pair of different multiplets to split into a sum of sigma-model actions of each multiplet. This phenomenon also persists if a larger number of non-equivalent multiplets are simultaneously included. We show that different multiplets may interact with each other only through mixed mass terms which can be set up for multiplets belonging to 'self-dual' pairs (q ia , q IA ) and (q Ia , q iA ). The multiplets from different pairs cannot interact at all. For a 'self-dual' pair of the twisted multiplets we give the most general form of the on-shell scalar potential
Evidence for dynamic SU(5) symmetry breaking in meson mass multiplets
International Nuclear Information System (INIS)
Frikkee, E.
1994-07-01
It is shown that the mass differences and multiplet pattern for pseudoscalar and vector mesons correspond to a chain of dynamic symmetry reductions SU(n) contains SU(n-1)xU(1). In this symmetry-reduction model, the differences between the masses of the quark flavours are the result of intra-hadronic interactions. Quark confinement is explained as a consequence of the fact that this symmetry breaking chain only occurs in hadrons. The results of a quantitative analysis of mass splittings in meson multiplets indicate that SU(5) is probably the highest symmetry for hadron states. In the proposed dynamic symmetry breaking scheme with five quark flavours there is no one-to-one correspondence between lepton and quark generations. (orig.)
Investigation of persistent Multiplets at the EGS reservoir of Soultz-Sous-Forêts, France
Lengliné, O.; Cauchie, L.; Schmittbuhl, J.
2017-12-01
During the exploitation of geothermal reservoirs, abundant seismicity is generally observed, especially during phases of hydraulic stimulations. The induced seismicity at the Enhanced Geothermal System of Soultz-Sous-Forêts in France, has been thoroughly studied over the years of exploitation. The mechanism at its origin has been related to both fluid pressure increases during stimulation and aseismic creeping movements. The fluid-induced seismic events often exhibit a high degree of similarity and the mechanism at the origin of these repeated events is thought to be associated with slow slip process where asperities on the rupture zone act several times.To have a better understanding of the mechanisms associated with such events and on the damaged zones involved during the hydraulic stimulations, we investigate the behavior of the multiplets and their persistent nature over several water injection intervals. For this purpose, we analyzed large datasets recorded from a borehole seismic network for several water injection periods (1993, 2000). For each stimulation interval, thousands of events are recorded at depth. We detected the events using a STA/LTA approach and classified them into families of comparable waveforms using an approach based on cross-correlation analysis. Classification of the seismic events is then improved depending on their location within the multiplets. For this purpose, inter-event distances within multiplets are examined and determined from cross-correlation analysis between pairs of events. These distances are then compared to the source dimensions derived from the estimation of the corner frequencies estimation. The multiplets properties (location, events size) are then investigated within and over several hydraulic tests. Hopefully these steps will lead to increase the knowledge on the repetitive nature of these events and the investigation of their persistence will outline the heterogeneities of the structures (regional stress
Morphologies and ages of star cluster pairs and multiplets in the Small Magellanic Cloud
de Oliveira, M. R.; Dutra, C. M.; Bica, E.; Dottori, H.
2000-10-01
An isophotal atlas of 75 star cluster pairs and multiplets in the Small Magellanic Cloud is presented, comprising 176 objects. They are concentrated in the SMC main body. The isophotal contours were made from Digitized Sky Survey* images and showed relevant structural features possibly related to interactions in about 25% of the sample. Previous N-body simulations indicate that such shapes could be due to tidal tails, bridges or common envelopes. The diameter ratio between the members of a pair is preferentially in the range 1 - 2, with a peak at 1. The projected separation is in the range ~ 3 - 22 pc with a pronounced peak at ~ 13 pc. For 91 objects it was possible to derive ages from Colour-Magnitude Diagrams using the OGLE-II photometric survey. The cluster multiplets in general occur in OB stellar associations and/or HII region complexes. This indicates a common origin and suggests that multiplets coalesce into pairs or single clusters in a short time scale. Pairs in the SMC appear to be mostly coeval and consequently captures are a rare phenomenon. We find evidence that star cluster pairs and multiplets may have had an important role in the dynamical history of clusters presently seen as large single objects. The images in this study are based on photographic data obtained using the UK Schmidt Telescope, which was operated by the Royal Observatory Edinburgh, with funding from the UK Science and Engineering Research Council, until 1988 June, and thereafter by the Anglo-Australian Observatory. Original plate material is copyright by the Royal Observatory Edinburgh and the Anglo-Australian Observatory. The plates were processed into the present compressed digital form with their permission. The Digitized Sky Survey was produced at the Space Telescope Science Institute under US Government grant NAG W-2166.
A three-flavor chiral effective model with four baryonic multiplets within the mirror assignment
Energy Technology Data Exchange (ETDEWEB)
Olbrich, Lisa; Zetenyi, Miklos; Giacosa, Francesco; Rischke, Dirk H. [Institute for Theoretical Physics, Goethe University Frankfurt am Main (Germany)
2016-07-01
Chiral symmetry requires the existence of chiral partners in the hadronic mass spectrum. In this talk, we address the question which is the chiral partner of the nucleon. We employ a chirally symmetric linear sigma model, where hadrons and their chiral partners are treated on the same footing. We construct four spin-1/2 baryon multiplets from left- and right-handed quarks as well as left- and right-handed diquarks. Two of these multiplets transform in a ''mirror'' way, which allows for chirally invariant mass terms. We then embed these baryonic multiplets into the Lagrangian of the extended Linear Sigma Model, which features (pseudo)scalar and (axial-)vector mesons, as well as glueballs. Reducing the Lagrangian to the two-flavor case, we obtain four doublets of nucleonic states. These mix to produce the positive-parity nucleon N(939) and the Roper resonance N(1440), as well as the negative-parity resonances N(1535) and N(1650). We determine the parameters of the nucleonic part of the Lagrangian from a fit to masses and decay properties of these states. Studying the limit of vanishing quark condensate, we conclude that N(939) and N(1535), as well as N(1440) and N(1650) form pairs of chiral partners.
Higgs mechanism and cosmological constant in N = 1 supergravity with inflaton in a vector multiplet
Energy Technology Data Exchange (ETDEWEB)
Aldabergenov, Yermek [Tokyo Metropolitan University, Department of Physics, Tokyo (Japan); Ketov, Sergei V. [Tokyo Metropolitan University, Department of Physics, Tokyo (Japan); The University of Tokyo, Kavli Institute for the Physics and Mathematics of the Universe (IPMU), Chiba (Japan); Tomsk Polytechnic University, Institute of Physics and Technology, Tomsk (Russian Federation)
2017-04-15
The N = 1 supergravity models of cosmological inflation with an inflaton belonging to a massive vector multiplet and spontaneous SUSY breaking after inflation are reformulated as the supersymmetric U(1) gauge theories of a massless vector superfield interacting with the Higgs and Polonyi chiral superfields, all coupled to supergravity. The U(1) gauge sector is identified with the U(1) gauge fields of the super-GUT coupled to supergravity, whose gauge group has a U(1) factor. A positive cosmological constant (dark energy) is included. The scalar potential is calculated, and its de Sitter vacuum solution is found to be stable. (orig.)
Diagnostics of spatial structure of vortex multiplets in a swirl flow
DEFF Research Database (Denmark)
Naumov, I. V.; Okulov, Valery; Sørensen, Jens Nørkær
2011-01-01
Results on investigation of vortex unstable breakdown are presented. The structure of vortex multiplets was visualized in a vertical cylindrical container made of transparent organic glass of the optic quality with the inner diameter of 288 mm and rotating upper lid. Visualization was performed....... Visualization of flow structure for unstable swirl flows and cylinder aspect ratios from 3.2 to 5.5 allowed first identification of these regimes as multispiral breakdowns with formation of helical-like vortex duplets, triplets and quadruplets....
International Nuclear Information System (INIS)
Ibrahim, Tarek; Nath, Pran
2010-01-01
The electric dipole moment (EDM) of the top quark is calculated in a model with a vector like multiplet which mixes with the third generation in an extension of the minimal supersymmetric standard model. Such mixings allow for new CP violating phases. Including these new CP phases, the EDM of the top in this class of models is computed. The top EDM arises from loops involving the exchange of the W, the Z as well as from the exchange involving the charginos, the neutralinos, the gluino, and the vector like multiplet and their superpartners. The analysis of the EDM of the top is more complicated than for the light quarks because the mass of the external fermion, in this case the top quark mass cannot be ignored relative to the masses inside the loops. A numerical analysis is presented and it is shown that the top EDM could be close to 10 -19 ecm consistent with the current limits on the EDM of the electron, the neutron and on atomic EDMs. A top EDM of size 10 -19 ecm could be accessible in collider experiments such as the International Linear Collider.
Intra- and inter-multiplet neutron transitions in an Fe4 magnetic cluster
International Nuclear Information System (INIS)
Amoretti, G.; Carretta, S.; Liviotti, E.; Caciuffo, R.; Cornia, A.; Gatteschi, D.; Kulda, J.
2002-01-01
We report the results of neutron spectroscopy for a tetranuclear iron cluster, Fe 4 (OCH 3 ) 6 (dpm) 6 (Hdpm=dipivaloylmethane), having an S=5 spin ground state. The experiments were carried out on a deuterated powder sample at ILL, Grenoble. The transitions within the ground multiplet, below 0.3 meV, were measured with a high-resolution time-of-flight spectrometer. Taking into account the presence of three different isomers, the parameters of the zero-field-splitting Hamiltonian have been determined. The results are discussed with reference to high-field electron paramagnetic resonance data. A non-dispersive peak at 7.8 meV, detected at T=1.4 K using a three-axis spectrometer with polarization analysis, is interpreted as the transition between the S=5 ground state and the two degenerate S=4 excited multiplets. The Q dependence of the cross section is discussed in comparison with the theoretical model. (orig.)
Intra- and inter-multiplet neutron transitions in an Fe{sub 4} magnetic cluster
Energy Technology Data Exchange (ETDEWEB)
Amoretti, G.; Carretta, S.; Liviotti, E. [INFM, Dipartimento di Fisica, Universita di Parma, Parco Area delle Scienze 7/A, 43 100 Parma (Italy); Caciuffo, R. [INFM, Dipartimento di Fisica e Ingegneria dei Materiali, Universita di Ancona, Via Brecce Bianche, 60 131 Ancona (Italy); Cornia, A. [Dipartimento di Chimica, Universita di Modena, Via G. Campi 183, 41 100 Modena (Italy); Gatteschi, D. [Dipartimento di Chimica, Universita di Firenze, Via della Lastruccia 5, 50 019 Sesto Fiorentino (FI) (Italy); Kulda, J. [Institut Laue Langevin, 6 rue J. Horowitz, 38 042 Grenoble (France)
2002-07-01
We report the results of neutron spectroscopy for a tetranuclear iron cluster, Fe{sub 4}(OCH{sub 3}){sub 6}(dpm){sub 6} (Hdpm=dipivaloylmethane), having an S=5 spin ground state. The experiments were carried out on a deuterated powder sample at ILL, Grenoble. The transitions within the ground multiplet, below 0.3 meV, were measured with a high-resolution time-of-flight spectrometer. Taking into account the presence of three different isomers, the parameters of the zero-field-splitting Hamiltonian have been determined. The results are discussed with reference to high-field electron paramagnetic resonance data. A non-dispersive peak at 7.8 meV, detected at T=1.4 K using a three-axis spectrometer with polarization analysis, is interpreted as the transition between the S=5 ground state and the two degenerate S=4 excited multiplets. The Q dependence of the cross section is discussed in comparison with the theoretical model. (orig.)
VizieR Online Data Catalog: New multiplet table for FeI (Nave+, 1994)
Nave, G.; Johansson, S.; Learner, R. C. M.; Thorne, A. P.; Brault, J. W.
1995-02-01
We have recorded spectra of iron-neon and iron-argon hollow cathode lamps in the region 1700A-5um (59,000-2000cm-1), with Fourier transform (FT) spectrometers at the National Solar Observatory, Tucson, Arizona, and Imperial College, London, UK, and with a high-resolution grating spectrograph at the National Institute of Standards and Technology, Gaithersburg, Maryland. The uncertainty of the strongest lines in the FT spectra is less than 0.002cm-1 (0.2mA at 3000A; 8mA at 2um). Pressure- and current-dependent shifts are less than 0.001cm-1 for transitions between low-lying levels, increasing to 0.006cm-1 for transitions between the most highly excited levels. We report 28 new energy levels of Fe I and revised values of another 818 levels. We have identified 9501 lines as due to 9759 transitions in Fe I, and these are presented in the form of a new multiplet table and finding list. This compares with the ~5500 lines due to 467 energy levels in the multiplet tables of Moore (1950, NBS Circ., No.488 and 1959, NBS Tech. note 30). The biggest increase is in the near-ultraviolet and near infrared, and many of the new lines are present in the solar spectrum. Experimental log (gf) values are included where they are available. A further 125 unidentified lines due to Fe I are given. (4 data files).
Chromoelectric dipole moment of the top quark in models with vectorlike multiplets
International Nuclear Information System (INIS)
Ibrahim, Tarek; Nath, Pran
2011-01-01
The chromoelectric dipole moment of the top quark is calculated in a model with a vectorlike multiplet, which mixes with the third generation in an extension of the minimal supersymmetric standard model. Such mixings allow for new CP violating phases. Including these new CP phases, the chromoelectric dipole moment that generates an electric dipole of the top in this class of models is computed. The top chromoelectric dipole moment operator arises from loops involving the exchange of the W, the Z, as well as from the exchange involving the charginos, the neutralinos, the gluino, and the vectorlike multiplet and their superpartners. The analysis of the chromoelectric dipole moment operator of the top is more complicated than for the light quarks because the mass of the external fermion, in this case the top quark mass, cannot be ignored relative to the masses inside the loops. A numerical analysis is presented and it is shown that the contribution to the top electric dipole moment (EDM) could lie in the range (10 -19 -10 -18 ) ecm, consistent with the current limits on the EDM of the electron, the neutron and on atomic EDMs. A top EDM of size (10 -19 -10 -18 ) ecm could be accessible in collider experiments such as at the LHC and at the International Linear Collider.
Systematics of ground state multiplets of atomic nuclei in the delta-interaction approach
Energy Technology Data Exchange (ETDEWEB)
Imasheva, L. T.; Ishkhanov, B. S.; Stepanov, M. E., E-mail: stepanov@depni.sinp.msu.ru [Moscow State University, Faculty of Physics (Russian Federation); Tretyakova, T. Yu. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)
2015-12-15
Pairing forces between nucleons in an atomic nucleus strongly influence its structure. One of the manifestations of pair interaction is the ground state multiplet (GSM) formation in the spectrum of low-lying excited states of even–even nuclei. The value of GSM splitting is determined by the value of pair interaction of nucleons; for each isotope, it can be estimated on the basis of experimental nuclear masses. The quality of this estimate is characterized by the degree of reproduction of GSM levels in the nucleus. The GSM systematics in even–even nuclei with a pair of identical nucleons in addition to the filled nuclear core is considered on the basis of delta interaction.
Core-collapse supernovae as possible counterparts of IceCube neutrino multiplets
Energy Technology Data Exchange (ETDEWEB)
Strotjohann, Nora Linn; Kowalski, Marek; Franckowiak, Anna [DESY, Zeuthen (Germany); Voge, Markus [Bonn Univ. (Germany). Physikalisches Institut; Collaboration: IceCube-Collaboration
2016-07-01
While an astrophysical neutrino flux has been detected by the IceCube Neutrino Observatory its sources remain so far unidentified. IceCube's Optical Follow-up Program is designed to search for the counterparts of neutrino multiplets using the full energy range of the IceCube detector down to 100 GeV. Two or more muon neutrinos arriving from the same direction within few seconds can trigger follow-up observations with optical and X-ray telescopes. Since 2010 the Palomar Transient Factory has followed up about 40 such neutrino alerts and detected several supernovae. Many of the detections are however likely random coincidences. In this talk I describe our search for supernovae and the prospects of identifying a supernova as a source of high-energy neutrinos.
Comparison of alternative methods for multiplet deconvolution in the analysis of gamma-ray spectra
International Nuclear Information System (INIS)
Blaauw, Menno; Keyser, Ronald M.; Fazekas, Bela
1999-01-01
Three methods for multiplet deconvolution were tested using the 1995 IAEA reference spectra: Total area determination, iterative fitting and the library-oriented approach. It is concluded that, if statistical control (i.e. the ability to report results that agree with the known, true values to within the reported uncertainties) is required, the total area determination method performs the best. If high deconvolution power is required and a good, internally consistent library is available, the library oriented method yields the best results. Neither Erdtmann and Soyka's gamma-ray catalogue nor Browne and Firestone's Table of Radioactive Isotopes were found to be internally consistent enough in this respect. In the absence of a good library, iterative fitting with restricted peak width variation performs the best. The ultimate approach as yet to be implemented might be library-oriented fitting with allowed peak position variation according to the peak energy uncertainty specified in the library. (author)
Ultra-narrow EIA spectra of 85Rb atom in a degenerate Zeeman multiplet system
Rehman, Hafeez Ur; Qureshi, Muhammad Mohsin; Noh, Heung-Ryoul; Kim, Jin-Tae
2015-05-01
Ultra-narrow EIA spectral features of thermal 85Rb atom with respect to coupling Rabi frequencies in a degenerate Zeeman multiplet system have been unraveled in the cases of same (σ+ -σ+ , π ∥ π) and orthogonal (σ+ -σ- , π ⊥ π)polarization configurations. The EIA signals with subnatural linewidth of ~ 100 kHz even in the cases of same circular and linear polarizations of coupling and probe laser have been obtained for the first time theoretically and experimentally. In weak coupling power limit of orthogonal polarization configurations, time-dependent transfer of coherence plays major role in the splitting of the EIA spectra while in strong coupling power, Mollow triplet-like mechanism due to strong power bring into broad split feature. The experimental ultra-narrow EIA features using one laser combined with an AOM match well with simulated spectra obtained by using generalized time-dependent optical Bloch equations.
Core-level satellites and outer core-level multiplet splitting in Mn model compounds
International Nuclear Information System (INIS)
Nelson, A. J.; Reynolds, John G.; Roos, Joseph W.
2000-01-01
We report a systematic study of the Mn 2p, 3s, and 3p core-level photoemission and satellite structures for Mn model compounds. Charge transfer from the ligand state to the 3d metal state is observed and is distinguished by prominent shake-up satellites. We also observe that the Mn 3s multiplet splitting becomes smaller as the Mn oxidation state increases, and that 3s-3d electron correlation reduces the branching ratio of the 7 S: 5 S states in the Mn 3s spectra. In addition, as the ligand electronegativity decreases, the spin-state purity is lost in the 3s spectra, as evidenced by peak broadening. Our results are best understood in terms of the configuration-interaction model including intrashell electron correlation, charge transfer, and final-state screening. (c) 2000 American Vacuum Society
International Nuclear Information System (INIS)
Giedt, Joel
2003-01-01
We compute the component field four-dimensional N = 1 supergravity Lagrangian that is obtained from a superfield Lagrangian in the U(1) K formalism with a linear dilaton multiplet. All fermionic terms are presented. In a variety of important ways, our results generalize those that have been reported previously, and are flexible enough to accommodate many situations of phenomenological interest in string-inspired effective supergravity, especially models based on orbifold compactifications of the weakly coupled heterotic string. We provide for an effective theory of hidden gaugino and matter condensation. We include supersymmetric Green-Schwarz counterterms associated with the cancellation of U(1) and modular duality anomalies; the modular duality counterterm is of a rather general form. Our assumed form for the dilaton Kaehler potential is quite general and can accommodate Kaehler stabilization methods. We note possible applications of our results. We also discuss the usefulness of the linear dilaton formulation as a complement to the chiral dilaton approach
OKADA, K; KOTANI, A; THOLE, BT
1992-01-01
Core-level X-ray photoemission spectra (XPS) are calculated for Ni and Co dihalides with an MX6 cluster model (M = Ni, Co; X = F, Cl, Br), where intra-atomic multiplet coupling as well as covalency mixing is taken into account. The effects of the intra-atomic configuration interaction between
International Nuclear Information System (INIS)
De Fanis, A; Pruemper, G; Hergenhahn, U; Kukk, E; Tanaka, T; Kitajima, M; Tanaka, H; Fritzsche, S; Kabachnik, N M; Ueda, K
2005-01-01
We employ a novel technique in which highly excited Rydberg states of Ne + 2p 4n p are populated via PCI-induced recapture of the near-threshold 1s photoelectron (De Fanis et al 2004 Phys. Rev. A 70 040702) to investigate valence inter-multiplet Auger transitions. The following series of the transitions have been observed: Ne + 2p 4 ( 1 D)np 2 L → Ne 2+ 2p 4 3 P J , Ne + 2p 4 ( 1 S)np 2 P →Ne 2+ 2p 4 3 P J and Ne + 2p 4 ( 1 S)np 2 P →Ne 2+ 2p 4 1 D. Their energy positions, quantum defects and the anisotropy parameters of the Auger electron emission have been determined. Experimental results are in good agreement with multi-configuration Dirac-Fock calculations carried out as a part of this study. The importance of interference effects for decays via naturally overlapping fine-structure components of the intermediate state is discussed
Neutron transitions within the S=10 ground multiplet of a Fe8 magnetic cluster
Carretta, S.; Liviotti, E.; Amoretti, G.; Caciuffo, R.; Caneschi, A.; Gatteschi, D.
2002-02-01
Inelastic neutron scattering has been used to determine the anisotropic spin Hamiltonian that splits the S=10 ground multiplet of the cluster (tacn)6Fe8O2(OH)12Br4.3(ClO4)3.76H2O (Fe8PCl), where (tacn) is the organic ligand 1,4,7-triazacyclononane. This single-molecule magnet,which is obtained from the well known Fe8Br cluster, by partial replacement of the bromide ions by perchlorate anions, presents a larger transverse anisotropy than the parent compound, the E/D ratio being 0.22 instead of 0.16. This is in agreement with the relaxation measurements in the pure quantum tunneling regime. The details of the neutron spectra detected at three different temperatures (2, 10, and 15 K) allowed us to determine the spin Hamiltonian parameters up to fourth order and to identify the main source of the transition linewidth broadening with the occupational disorder of the bromide and perchlorate ions, rather than with the random internal dipolar field distribution.
A method for interpolating asymmetric peak shapes in multiplet γ-ray spectra
International Nuclear Information System (INIS)
Wang Siguang; Mao Yajun; Zhu Bo; Liang Yutie; Tang Peijia
2009-01-01
The peak shapes of γ-rays at various energies must be known before unfolding the multiplet spectra obtained by using semiconductor or scintillation detectors. Traditional methods describe isolated peaks with multi-parameter fitting functions, and assume that most of these parameters do not vary with energy because it is rare to find a spectrum with enough isolated peaks to constrain their dependence. We present an algorithm for interpolating the γ-ray profile at any intermediate energy given a pair of isolated γ-ray peaks from the spectrum under consideration. The algorithm is tested on experimental data and leads to a good agreement between the interpolated profile and the fitting function. This method is more accurate than the traditional approach, since all aspects of the peak shape are allowed to vary with energy. New definitions of Left-Half Width at Half Maximum, and Right-Half Width at Half Maximum for peak shape description are introduced in this paper. (authors)
Generalized isobaric multiplet mass equation and its application to the Nolen-Schiffer anomaly
Dong, J. M.; Zhang, Y. H.; Zuo, W.; Gu, J. Z.; Wang, L. J.; Sun, Y.
2018-02-01
The Wigner isobaric multiplet mass equation (IMME) is the most fundamental prediction in nuclear physics with the concept of isospin. However, it was deduced based on the Wigner-Eckart theorem with the assumption that all charge-violating interactions can be written as tensors of rank two. In the present work, the charge-symmetry breaking (CSB) and charge-independent breaking (CIB) components of the nucleon-nucleon force, which contribute to the effective interaction in nuclear medium, are established in the framework of Brueckner theory with AV18 and AV14 bare interactions. Because such charge-violating components can no longer be expressed as an irreducible tensor due to density dependence, its matrix element cannot be analytically reduced by the Wigner-Eckart theorem. With an alternative approach, we derive a generalized IMME (GIMME) that modifies the coefficients of the original IMME. As the first application of GIMME, we study the long-standing question of the origin of the Nolen-Schiffer anomaly (NSA) found in the Coulomb displacement energy of mirror nuclei. We find that the naturally emerged CSB term in GIMME is largely responsible for explaining the NSA.
On the line intensity ratios of prominent Si II, Si III, and Si IV multiplets
International Nuclear Information System (INIS)
Djenize, S.; Sreckovic, A.; Bukvic, S.
2010-01-01
Line intensities of singly, doubly and triply ionized silicon (Si II, Si III, and Si IV, respectively) belonging to the prominent higher multiplets, are of interest in laboratory and astrophysical plasma diagnostics. We measured these line intensities in the emission spectra of pulsed helium discharge. The Si II line intensity ratios in the 3s3p 22 D-3s 2 4p 2 P o , 3s 2 3d 2 D-3s 2 4f 2 F o , and 3s 2 4p 2 P o -3s 2 4d 2 D transitions, the Si III line intensity ratios in the 3s3d 3 D-3s4p 3 P o , 3s4p 3 P o -3s4d 3 D, 3s4p 3 P o -3s5s 3 S, 3s4s 3 S-3s4p 3 P o , and 3s4f 3 F o -3s5g 3 G transitions, and the Si IV line intensity ratios in the 4p 2 P o -4d 2 D and 4p 2 P o -5s 2 S transitions were obtained in a helium plasma at an electron temperature of about 17,000 ± 2000 K. Line shapes were recorded using a spectrograph and an ICCD camera as a highly-sensitive detection system. The silicon atoms were evaporated from a Pyrex discharge tube designed for the purpose. They represent impurities in the optically thin helium plasma at the silicon ionic wavelengths investigated. The line intensity ratios obtained were compared with those available in the literature, and with values calculated on the basis of available transition probabilities. The experimental data corresponded well with line intensity ratios calculated using the transition probabilities obtained from a Multi Configuration Hartree-Fock approximation for Si III and Si IV spectra. We recommend corrections of some Si II transition probabilities.
DES meets Gaia: discovery of strongly lensed quasars from a multiplet search
Energy Technology Data Exchange (ETDEWEB)
Agnello, A.; et al.
2017-11-10
We report the discovery, spectroscopic confirmation and first lens models of the first two, strongly lensed quasars from a combined search in WISE and Gaia over the DES footprint. The four-image lensWGD2038-4008 (r.a.=20:38:02.65, dec.=-40:08:14.64) has source- and lens-redshifts $z_{s}=0.777 \\pm 0.001$ and $z_l = 0.230 \\pm 0.002$ respectively. Its deflector has effective radius $R_{\\rm eff} \\approx 3.4^{\\prime\\prime}$, stellar mass $\\log(M_{\\star}/M_{\\odot}) = 11.64^{+0.20}_{-0.43}$, and shows extended isophotal shape variation. Simple lens models yield Einstein radii $R_{\\rm E}=(1.30\\pm0.04)^{\\prime\\prime},$ axis ratio $q=0.75\\pm0.1$ (compatible with that of the starlight) and considerable shear-ellipticity degeneracies. The two-image lensWGD2021-4115 (r.a.=20:21:39.45, dec.=--41:15:57.11) has $z_{s}=1.390\\pm0.001$ and $z_l = 0.335 \\pm 0.002$, and Einstein radius $R_{\\rm E} = (1.1\\pm0.1)^{\\prime\\prime},$ but higher-resolution imaging is needed to accurately separate the deflector and faint quasar image. We also show high-rank candidate doubles selected this way, some of which have been independently identified with different techniques, and discuss a DES+WISE quasar multiplet selection.
Chapter 14. Systems of identical particles
International Nuclear Information System (INIS)
Anon.
1977-01-01
For the systems of identical particles it is necessary to introduce the postulate of symmetrization to describe quantum systems. Physical implications of this postulate are presented: bosons, fermions and Pauli exclusion principle; quantum statistics; interferences between direct process and exchange process. Permutation operators are also exposed. In complement are studied: approximation of central field, electron configurations, energy levels of helium atom (configurations, terms, multiplets), physical properties of electron gas (application to solids) [fr
International Nuclear Information System (INIS)
Yablon, J.R.
1989-01-01
It is shown how the internal flavor symmetries of left-handed chiral quarks and leptons within a single generation, form part of an adjoint representation of the simple local gauge group SU(4). This adjointness of representation suggests the possibility of decomposing quarks and leptons into a more basic set of preon fields, which form the fundamental representation of SU(4). While this decomposition properly accounts for the internal symmetries of quarks and leptons, it ignores their spacetime symmetries, particularly spin. To account for spin, one instead uses a 4 x 4 version of the gauge group SO(4), which reproduces all of the SU(4) internal symmetries, and also results in a more satisfactory spin content
Nishino, Hitoshi; Rajpoot, Subhash
2018-03-01
We formulate an N = (2 , 0) system in D = 3 + 3 dimensions consisting of a Yang-Mills (YM)-multiplet (ˆ μ ˆ IA, λˆI), a self-dual non-Abelian tensor multiplet (ˆ μ ˆ ν ˆ IB, χˆI ,φˆI), and an extra vector multiplet (C ˆ μ ˆ IC, ρˆI). We next perform the dimensional reductions of this system into D = 2 + 2, and obtain N = (1 , 1) systems with a self-dual YM-multiplet (AIμ ,λI), a self-dual tensor multiplet (BIμν , χI , φI), and an extra vector multiplet (CIμ , ρI). In D = 2 + 2, we reach two distinct theories: 'Theory-I' and 'Theory-II'. The former has the self-dual field-strength Hμν(+)I of CIμ already presented in our recent paper, while the latter has anti-self-dual field strength Hμν(-)I. As an application, we show that Theory-II actually generates supersymmetric-KdV equations in D = 1 + 1. Our result leads to a new conclusion that the D = 3 + 3 theory with non-Abelian tensor multiplet can be a 'Grand Master Theory' for self-dual multiplet and self-dual YM-multiplet in D = 2 + 2, that in turn has been conjectured to be the 'Master Theory' for all supersymmetric integrable theories in D ≤ 3.
International Nuclear Information System (INIS)
Whitney, K G; Dasgupta, A; Davis, J; Coverdale, C A
2007-01-01
Two atomic models of the population dynamics of substates within the n 4 and n = 3 multiplets of nickel-like tungsten and beryllium-like iron, respectively, are described in this paper. The flexible atomic code (FAC) is used to calculate the collisional and radiative couplings and energy levels of the excited states within these ionization stages. These atomic models are then placed within larger principal-quantum-number-based ionization dynamic models of both tungsten and iron plasmas. Collisional-radiative equilibrium calculations are then carried out using these models that demonstrate how the multiplet substates depart from local thermodynamic equilibrium (LTE) as a function of ion density. The effect of these deviations from LTE on the radiative and collisional deexcitation rates of lumped 3s, 3p, 3d, 4s, 4p, 4d and 4f states is then calculated and least-squares fits to the density dependence of these lumped-state rate coefficients are obtained. The calculations show that, with the use of lumped-state models (which are in common use), one can accurately model the L- and M-shell ionization dynamics occurring in present-day Z-pinch experiments only through the addition of these extra, non-LTE-induced, rate coefficient density dependences. However, the derivation and use of low-order polynomial fits to these density dependences makes lumped-state modelling both viable and of value for post-processing analyses
Energy Technology Data Exchange (ETDEWEB)
Calkins, Mathew; Gates, D.E.A.; Gates, Sylvester James Jr.; McPeak, Brian [Center for String and Particle Theory, Department of Physics, University of Maryland,College Park, MD 20742-4111 (United States)
2014-05-13
We present evidence of the existence of a 1D, N = 16 SUSY hologram that can be used to understand representation theory aspects of a 4D, N = 4 supersymmetrical vector multiplet. In this context, the long-standing “off-shell SUSY” problem for the 4D, N = 4 Maxwell supermultiplet is precisely formulated as a problem in linear algebra.
Energy Technology Data Exchange (ETDEWEB)
Liu, R.; Conradie, J.; Erasmus, E., E-mail: erasmuse@ufs.ac.za
2016-01-15
Graphical abstract: Synopsis and pictogram for Table of contents The Cr 2p{sub 3/2} peaks obtained from X-ray photoelectron spectra (XPS) of a series of chromium(III) β-diketonato complexes were fitted with calculated multiplet peaks. The ratio of the fac and mer isomers obtained from XPS compared very well with the Boltzmann calculated ratio. The electronegativity of the R-groups on the β-diketonato ligand influences the XPS peak positions. - Highlights: • β-diketonato complexes Cr(RCOCHCOR’){sub 3} • Cr 2p{sub 3/2} XPS peaks fitted with calculated multiplet peaks. • Different calculated multiplet peaks fit the Cr 2p{sub 3/2} peak for fac and mer isomers. • XPS peak positions influenced by the electronegativity of the R- and R'-group. - Abstract: X-ray photoelectron spectra (XPS) measurements of a series of chromium(III) β-diketonato complexes of the Cr 2p spectra was fitted with calculated multiplet peaks. The XPS of these Cr(III) complexes did not exhibit fine structure, however, well-defined line shapes could be fitted to the Cr 2p{sub 3/2} envelope. The splitting patterns obtained for the Cr(III) β-diketonato complexes compared well with the multiplet splitting predicted by Gupta and Sen for the free Cr(III) ion. The Cr(III) β-diketonato complexes containing unsymmetrically substituted β-diketonato ligands, which display both the fac and mer isomers, could be fitted with two sets of multiplets and were useful in determining the ratio between the fac and mer isomers, which was compared with the Boltzman calculated ratio obtained from density functional theory energies. The obtained binding energy of the first multiplet splitting peak of the Cr 2p{sub 3/2} envelope was found to be dependent on the combined Gordy group electronegativity of the R-groups substituted on the β-diketonato ligand (RCOCHCOR′){sup −}.
New particle-hole symmetries and the extended interacting boson model
De Coster, C; Decroix, B; Heyde, Kris L G; Oros, A M
1998-01-01
We describe shape coexistence and intruder many-particle-hole (mp-nh)excitations in the extended interacting boson model EIBM and EIBM-2,combining both the particle-hole and the charge degree of freedom.Besides the concept of I-spin multiplets and subsequently $SU(4)$ multiplets, we touch upon the existence of particle-hole mixed symmetry states. We furthermore describe regular and intrudermany-particle-hole excitations in one nucleus on an equal footing, creating (annihilating) particle-hole pairs using the K-spin operatorand studying possible mixing between these states. As a limiting case,we treat the coupling of two IBM-1 Hamiltonians, each decribing the regular and intruder excitations respectively, in particular lookingat the $U(5)$-$SU(3)$ dynamical symmetry coupling. We apply such coupling scheme to the Po isotopes.
An N=8 superconformal particle in the half-plane
Energy Technology Data Exchange (ETDEWEB)
Lechtenfeld, Olaf, E-mail: lechtenf@itp.uni-hannover.d [Leibniz Universitaet, Hannover (Germany). Inst. fuer Theoretische Physik; Toppan, Francesco, E-mail: toppan@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)
2011-07-01
By imposing global supersymmetry and scale invariance we construct an N=8 superconformal mechanical system based on the inhomogeneous (2,8,6) linear multiplet. The unique action describes a special Kahler sigma model with a Calogero-type potential and Fayet-Iliopoulos terms. The classical dynamics of the two propagating bosons is restricted to a (warped) half-plane and bounded. We numerically inspect typical trajectories of this special particle. (author)
Linewidth studies on the the NI(4S-4P) resonance multiplet. [applicable to analysis of dayglow
Erdman, P. W.; Zipf, E. C.
1983-01-01
Doppler broadening of the 8691, 8212, and 1200-A multiplet lines of N I is investigated experimentally, and its implications for the interpretation of the earth's 1200-A UV dayglow are considered. A regulated 100-eV, 1-mA electron beam is passed through N2 at 300 K and about 0.0005 torr flowing through a collision chamber within a UHV system, and the radiation emitted is observed with a temperature-stabilized short-focal length monochromator with a bandpass of 0.2 A in the IR and an effective UV resolution (in second-order operation with a 3600-groove/mm plane grating) of about 0.04 A. Both the IR and VUV lines are found to be broadened to about 25 times the thermal Doppler linewidth, with the IR transitions accounting for more than half of the total N(4P) cross section at 100 eV. The kinetic energy of the N(4P) atoms produced by dissociative excitation is such that their 1200-A resonance radiation (2p2 3s4P - 2p3 4SO) would be optically thin in the upper atmosphere, contrary to what has been observed. A need to revise some aspects of current UV-dayglow models is identified.
Pinjari, Rahul V; Delcey, Mickaël G; Guo, Meiyuan; Odelius, Michael; Lundberg, Marcus
2014-09-28
The metal L-edge (2p → 3d) X-ray absorption spectra are affected by a number of different interactions: electron-electron repulsion, spin-orbit coupling, and charge transfer between metal and ligands, which makes the simulation of spectra challenging. The core restricted active space (RAS) method is an accurate and flexible approach that can be used to calculate X-ray spectra of a wide range of medium-sized systems without any symmetry constraints. Here, the applicability of the method is tested in detail by simulating three ferric (3d(5)) model systems with well-known electronic structure, viz., atomic Fe(3+), high-spin [FeCl6](3-) with ligand donor bonding, and low-spin [Fe(CN)6](3-) that also has metal backbonding. For these systems, the performance of the core RAS method, which does not require any system-dependent parameters, is comparable to that of the commonly used semi-empirical charge-transfer multiplet model. It handles orbitally degenerate ground states, accurately describes metal-ligand interactions, and includes both single and multiple excitations. The results are sensitive to the choice of orbitals in the active space and this sensitivity can be used to assign spectral features. A method has also been developed to analyze the calculated X-ray spectra using a chemically intuitive molecular orbital picture.
Chicherin, Dmitry
2017-03-09
We study the multipoint super-correlation functions of the full non-chiral stress-tensor multiplet in N=4 super-Yang-Mills theory in the Born approximation. We derive effective supergraph Feynman rules for them. Surprisingly, the Feynman rules for the non-chiral correlators differ only slightly from those for the chiral correlators. We rely on the formulation of the theory in Lorentz harmonic chiral (LHC) superspace elaborated in the twin paper \\cite{PartI}. In this approach only the chiral half of the supersymmetry is manifest. The other half is realized by nonlinear and nonlocal transformations of the LHC superfields. However, at Born level only the simple linear part of the transformations is relevant. It corresponds to effectively working in the self-dual sector of the theory. Our method is also applicable to a wider class of supermultiplets like all the half-BPS operators and the Konishi multiplet.
D=1 supergravity and spinning particles
International Nuclear Information System (INIS)
Holten, J.W. van.
1995-01-01
In this paper I review the multiplet calculus of N-1, D=1 local supersymmetry with applications to the construction of models for spinning particles in background fields, and models with space-time supersymmetry. New features include a non-linear realization of the local supersymmetry algebra and the coupling to anti-symmetric tensor fields of both odd and even rank. The non-linear realization allows the construction of a D=1 cosmological-constant term, which provides a mass term in the equations of motion. (orig.)
Effect of heavy particles in low-energy light-particle processes
International Nuclear Information System (INIS)
Chan, L.H.; Hagiwara, T.; Ovrut, B.
1979-01-01
The ''decoupling theorem'' of Appelquist and Carazzone is found not always to be applicable to light-scalar-particle processes in spontaneously broken theories. If the Higgs scalar is considered to be light, then Higgs-scalar processes see the effect of heavy fermions and heavy vector gauge bosons at the one-loop level. If there is more than one scalar multiplet in a spontaneously broken gauge theory, the effect of a heavy Higgs particle in light-scalar-particle processes is significant at the tree level. In the latter case, such an effect can be absorbed completely into an effective phi 4 coupling constant, lambda/sub eff/, of the light particle provided that lambda/sub eff/ is positive definite
Budi-Santoso, Agus; Lesage, Philippe
2016-07-01
We present a study of the seismic velocity variations that occurred in the structure before the large 2010 eruption of Merapi volcano. For the first time to our knowledge, the technique of coda wave interferometry is applied to both families of similar events (multiplets) and to correlation functions of seismic noise. About half of the seismic events recorded at the summit stations belong to one of the ten multiplets identified, including 120 similar events that occurred in the last 20 hr preceding the eruption onset. Daily noise cross-correlation functions (NCF) were calculated for the six pairs of short-period stations available. Using the stretching method, we estimate time-series of apparent velocity variation (AVV) for each multiplet and each pair of stations. No significant velocity change is detected until September 2010. From 10 October to the beginning of the eruption on 26 October, a complex pattern of AVV is observed with amplitude of up to ±1.5 per cent. Velocity decrease is first observed from families of deep events and then from shallow earthquakes. In the same period, AVV with different signs and chronologies are estimated from NCF calculated for various station pairs. The location in the horizontal plane of the velocity perturbations related with the AVV obtained from NCF is estimated by using an approach based on the radiative transfer approximation. Although their spatial resolution is limited, the resulting maps display velocity decrease in the upper part of the edifice in the period 12-25 October. After the eruption onset, the pattern of velocity perturbations is significantly modified with respect to the previous one. We interpret these velocity variations in the framework of a scenario of magmatic intrusion that integrates most observations. The perturbation of the stress field associated with the magma migration can induce both decrease and increase of the seismic velocity of rocks. Thus the detected AVVs can be considered as precursors of
International Nuclear Information System (INIS)
El Naschie, M.S.
2005-01-01
We motivate the concept of infinitely large and hierarchical matrices in connection with the eight-dimensional super Riemannian tensor and the unification of all fundamental forces. Subsequently, we derive the number of particle-like states and the expectation value of the number of elementary particle content of a minimally extended standard model using the total number of tadpoles and anomaly cancellation condition:nH+29nt-nv=R(8)-N(SM)=2α-bar 0-1=273 where n H is the number of hyper multiplets, n t the number of tensor multiplets, n v the vector multiplets, R (8) is the number of independent components of Riemann's curvature tensor in eight dimensions, N(SM) is the number of elementary particles content of the standard model and α-bar 0 is the inverse fine structure constant. We can conclude that N(SM)=66. Consequently, we conjecture that five Higgs particles should be involved in the standard model
de Angelis, G.; Wiedemann, K. T.; Martinez, T.; Orlandi, R.; Petrovici, A.; Sahin, E.; Valiente-Dobón, J. J.; Tonev, D.; Lunardi, S.; Nara Singh, B. S.; Wadsworth, R.; Gadea, A.; Kaneko, K.; Bizzeti, P. G.; Bizzeti-Sona, A. M.; Blank, B.; Bracco, A.; Carpenter, M. P.; Chiara, C. J.; Farnea, E.; Gottardo, A.; Greene, J. P.; Lenzi, S. M.; Leoni, S.; Lister, C. J.; Mengoni, D.; Napoli, D. R.; Pechenaya, O. L.; Recchia, F.; Reviol, W.; Sarantites, D. G.; Seweryniak, D.; Ur, C. A.; Zhu, S.
2012-03-01
Excited states of the N=Z=33 nucleus 66As have been populated in a fusion-evaporation reaction and studied using γ-ray spectroscopic techniques. Special emphasis was put into the search for candidates for the T=1 states. A new 3+ isomer has been observed with a lifetime of 1.1(3) ns. This is believed to be the predicted oblate shape isomer. The excited levels are discussed in terms of the shell model and of the complex excited Vampir approaches. Coulomb energy differences are determined from the comparison of the T=1 states with their analog partners. The unusual behavior of the Coulomb energy differences in the A=70 mass region is explained through different shape components (oblate and prolate) within the members of the same isospin multiplets. This breaking of the isospin symmetry is attributed to the correlations induced by the Coulomb interaction.
Search of unified theory of basic types of elementary particle interactions
International Nuclear Information System (INIS)
Anselm, A.
1981-01-01
Four types of forces are described (strong, weak, electromagnetic and gravitational) mediating the basic interactions of quarks and leptons, and attempts are reported of forming a unified theory of all basic interactions. The concepts are discussed, such as the theory symmetry (eg., invariance in relation to the Lorentz transformations) and isotopic symmetry (based on the interchangeability of particles in a given isotopic multiplet). Described are the gauge character of electromagnetic and gravitational interactions, the violation of the gauge symmetry and the mechanism of particle confinement. (H.S.)
... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution — ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...
International Nuclear Information System (INIS)
Aoki, Yuji; Namiki, Takahiro; Saha, Shanta R.; Sato, Hideyuki; Tayama, Takashi; Sakakibara, Toshiro; Shiina, Ryousuke; Shiba, Hiroyuki; Sugawara, Hitoshi
2011-01-01
The filled skutterudite PrRu 4 P 12 is known to undergo an unconventional charge order phase transition at 63 K, below which two sublattices with distinct f-electron crystalline-electric-field ground states are formed. In this paper, we study experimentally and theoretically the properties of the charge order phase at very low temperature, particularly focusing on the nature of the degenerate triplet ground state on one of the sublattices. First, we present experimental results of specific heat and magnetization measured with high quality single crystals. In spite of the absence of any symmetry breaking, the specific heat shows a peak structure at T p =0.30 K in zero field; it shifts to higher temperatures as the magnetic field is applied. In addition, the magnetization curve has a remarkable rounding below 1 T. Then, we study the origin of these experimental findings by considering the hyperfine interaction between 4f electron and nuclear spin. We demonstrate that the puzzling behaviors at low temperatures can be well accounted for by the formation of 4f-electron-nuclear hyperfine-coupled multiplets, the first thermodynamical observation of its kind. (author)
International Nuclear Information System (INIS)
Kochur, A.G.; Dudenko, A.I.; Petrov, I.D.; Demekhin, V.F.
2007-01-01
The Ar i+ ion yields upon the decay of the Ar1s -1 4p state are calculated in one-electron configuration-average approximation considering shake up, shake down and shake off processes as well as the ejection of electrons in inter-multiplet Auger transitions. Our calculation underestimates the production of the higher-charged ions which may indicate limitations of the one-electron approximation, and of the step-by-step cascade model
Prototype models for particle structure in gauge supersymmetry
International Nuclear Information System (INIS)
Nath, P.; Arnowitt, R.
1981-01-01
Particle content in prototype models of gauge supersymmetry is examined. The properties of the prototype models which are in common with those of gauge supersymmetries are the initial non-diagonality of the quadratic part of the action, global supersymmetry invariance and the existence of a mass parameter in the quadratic part of the action. The analysis exhibits the particle content of prototype models to consist of normal poles and sets of complex conjugate poles on the physical sheet. Diagonalization of the hamiltonian can be carried out for such systems (in contrast to the prototype model of conformal supergravity where dipole ghosts arose). Essentially the pole structure observed in the prototype models of gauge supersymmetry is the supersymmetric analogue of the Lee-Wick phenomenon where the normal and the complex conjugate poles form global multiplets. (orig.)
Phenomenology of Higgs particles
International Nuclear Information System (INIS)
Jarlskog, C.; Stockholm Univ.
1985-01-01
These lecture notes are organized as follows: 1. Introduction, 2. Interactions and decay modes of the Standard Higgs phisub(O), 3. Nonstandard Higgs multiplets, 4. Upper limits on the Higgs mass, 5. Lower limits on the Higgs mass, 6. Production mechanisms for the Standard Higgs, 7. Outlook. (orig.)
Santos, Sara; Graça, José
2014-01-01
Suberin is a biopolyester responsible for the protection of secondary plant tissues, and yet its molecular structure remains unknown. The C18:1 ω-hydroxyacid and the C18:1 α,ω-diacid are major monomers in the suberin structure, but the configuration of the double bond remains to be elucidated. To unequivocally define the configuration of the C18:1 suberin acids. Pure C18:1 ω-hydroxyacid and C18:1 α,ω-diacid, isolated from cork suberin, and two structurally very close C18:1 model compounds of known stereochemistry, methyl oleate and methyl elaidate, were analysed by NMR spectroscopy, Fourier transform infrared (FTIR) and Raman spectroscopy, and GC-MS. The GC-MS analysis showed that both acids were present in cork suberin as only one geometric isomer. The analysis of dimethyloxazoline (DMOX) and picolinyl derivatives proved the double bond position to be at C-9. The FTIR spectra were concordant with a cis-configuration for both suberin acids, but their unambiguous stereochemical assignment came from the NMR analysis: (i) the chemical shifts of the allylic (13) C carbons were shielded comparatively to the trans model compound, and (ii) the complex multiplets of the olefinic protons could be simulated only with (3) JHH and long-range (4) JHH coupling constants typical of a cis geometry. The two C18:1 suberin acids in cork are (Z)-18-hydroxyoctadec-9-enoic acid and (Z)-octadec-9-enedoic acid. Copyright © 2013 John Wiley & Sons, Ltd.
International Nuclear Information System (INIS)
Kutschera, W.
1984-01-01
The use of Accelerator Mass Spectrometry (AMS) to search for hypothetical particles and known particles of rare processes is discussed. The hypothetical particles considered include fractionally charged particles, anomalously heavy isotopes, and superheavy elements. The known particles produced in rare processes discussed include doubly-charged negative ions, counting neutrino-produced atoms in detectors for solar neutrino detection, and the spontaneous emission of 14 C from 223 Ra. 35 references
International Nuclear Information System (INIS)
Charpak, G.
2000-01-01
In this article G.Charpak presents the principles on which particle detection is based. Particle accelerators are becoming more and more powerful and require new detectors able to track the right particle in a huge flux of particles. The gigantic size of detectors in high energy physics is often due to the necessity of getting a long enough trajectory in a magnetic field in order to deduce from the curvature an accurate account of impulses in the reaction. (A.C.)
International Nuclear Information System (INIS)
Chinowsky, W.
1989-01-01
Work done in the mid 1950s at Brookhaven National Laboratory on strange particles is described. Experiments were done on the Cosmotron. The author describes his own and others' work on neutral kaons, lambda and theta particles and points out the theoretical gap between predictions and experimental findings. By the end of the decade, the theory of strange particles was better understood. (UK)
The penta-quark: a new kind of elementary particle?
International Nuclear Information System (INIS)
Goeke, K.; Praszatowicz, M.
2005-01-01
The discovery of the exotic Θ + with minimal quark structure uudds-bar may provide a sensation since, if confirmed, it is the first baryonic particle that cannot be composed of three quarks. The chiral quark soliton description of baryons has predicted the mass and an upper limit for the decay width of this particle prior to the experiments and in agreement with the present data. The model corresponds to a relativistic mean field description of the nucleon, where the quarks move in a self-consistent mean field of pionic and kaonic character. It uses an effective chiral Lagrangian based on spontaneously broken chiral symmetry of the QCD. In a natural way the chiral quark soliton model describes the well known lowest two multiplets (8, 1 + /2), (10, 3 + /2) and it predicts two more exotic particles being members of an anti-decuplet (10-bar, 1 + /2) consisting of penta-quarks. The very narrow width of the Θ + can be explained by the small overlap of the 5-quark light cone wave function of the Θ + with the small 5-quark light cone component of the wave function of the nucleon. If confirmed, Θ + will not only be a new kind of subatomic particle but will seriously influence our understanding of the structure of ordinary nucleons. (authors)
Energy Technology Data Exchange (ETDEWEB)
Raju, M.R.
1993-09-01
Particle therapy has a long history. The experimentation with particles for their therapeutic application got started soon after they were produced in the laboratory. Physicists played a major role in proposing the potential applications in radiotherapy as well as in the development of particle therapy. A brief review of the current status of particle radiotherapy with some historical perspective is presented and specific contributions made by physicists will be pointed out wherever appropriate. The rationale of using particles in cancer treatment is to reduce the treatment volume to the target volume by using precise dose distributions in three dimensions by using particles such as protons and to improve the differential effects on tumors compared to normal tissues by using high-LET radiations such as neutrons. Pions and heavy ions combine the above two characteristics.
International Nuclear Information System (INIS)
Raju, M.R.
1993-01-01
Particle therapy has a long history. The experimentation with particles for their therapeutic application got started soon after they were produced in the laboratory. Physicists played a major role in proposing the potential applications in radiotherapy as well as in the development of particle therapy. A brief review of the current status of particle radiotherapy with some historical perspective is presented and specific contributions made by physicists will be pointed out wherever appropriate. The rationale of using particles in cancer treatment is to reduce the treatment volume to the target volume by using precise dose distributions in three dimensions by using particles such as protons and to improve the differential effects on tumors compared to normal tissues by using high-LET radiations such as neutrons. Pions and heavy ions combine the above two characteristics
CERN. Geneva
2007-01-01
The understanding of the Universe at the largest and smallest scales traditionally has been the subject of cosmology and particle physics, respectively. Studying the evolution of the Universe connects today's large scales with the tiny scales in the very early Universe and provides the link between the physics of particles and of the cosmos. This series of five lectures aims at a modern and critical presentation of the basic ideas, methods, models and observations in today's particle cosmology.
Asakura, Daisuke; Nanba, Yusuke; Makinose, Yuki; Matsuda, Hirofumi; Glans, Per-Anders; Guo, Jinghua; Hosono, Eiji
2018-04-17
We analyzed the Fe 3d electronic structure in LiFePO 4 /FePO 4 (LFP/FP) nanowire with a high cyclability by using soft X-ray emission spectroscopy (XES) combined with configuration-interaction full-multiplet (CIFM) calculation. The ex situ Fe L 2,3 -edge resonant XES (RXES) spectra for LFP and FP are ascribed to oxidation states of Fe 2+ and Fe 3+ , respectively. CIFM calculations for Fe 2+ and Fe 3+ states reproduced the Fe L 3 RXES spectra for LFP and FP, respectively. In the calculations for both states, the charge-transfer energy was considerably larger than those for typical iron oxides, indicating very little electron transfer from the O 2p to Fe 3d orbitals and a weak hybridization on the Fe-O bond during the charge-discharge reactions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
International Nuclear Information System (INIS)
Kamal, Anwar
2014-01-01
Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.
Chang, Manchium (Inventor); Colvin, Michael S. (Inventor)
1989-01-01
Magnetic polymer particles are formed by swelling porous, polymer particles and impregnating the particles with an aqueous solution of precursor magnetic metal salt such as an equimolar mixture of ferrous chloride and ferric chloride. On addition of a basic reagent such as dilute sodium hydroxide, the metal salts are converted to crystals of magnetite which are uniformly contained througout the pores of the polymer particle. The magnetite content can be increased and neutral buoyancy achieved by repetition of the impregnaton and neutralization steps to adjust the magnetite content to a desired level.
International Nuclear Information System (INIS)
Ress, R.I.
1976-01-01
Charged particles are entrained in a predetermined direction, independent of their polarity, in a circular orbit by a magnetic field rotating at high speed about an axis in a closed cylindrical or toroidal vessel. The field may be generated by a cylindrical laser structure, whose beam is polygonally reflected from the walls of an excited cavity centered on the axis, or by high-frequency energization of a set of electromagnets perpendicular to the axis. In the latter case, a separate magnetostatic axial field limits the orbital radius of the particles. These rotating and stationary magnetic fields may be generated centrally or by individual magnets peripherally spaced along its circular orbit. Chemical or nuclear reactions can be induced by collisions between the orbiting particles and an injected reactant, or by diverting high-speed particles from one doughnut into the path of counterrotating particles in an adjoining doughnut
International Nuclear Information System (INIS)
Bednar, M.; Hron, J.
2001-01-01
Current insight into mesons and baryons is highlighted, their classification is given, and their arrangement into multiplets is described. A brief chronological overview of discoveries of the most important mesons and baryons is presented, followed by a description of the attempts to find fundamental particles between mesons and baryons, which could be composed of other mesons and baryons (Fermi-Yang model, Sakata model, Ikea-Ohnuki-Ogawa model). The attempts ultimately led to the formulation of the quark model. The quark structure of some mesons and baryons is presented. The quark model foresees the existence of mesons and baryons that have not yet been discovered. (Z.J.)
Hilke, Hans Jürgen
1992-01-01
We shall discuss the principles of the main techniques applied to particle detection (including front-end electronics), the construction and performance of some of the devices presently in operation and a few ideas on future developments.
International Nuclear Information System (INIS)
Evans, D.S.
1987-01-01
The problems concerning the aurora posed prior to the war are now either solved in principle or were restated in a more fundamental form. The pre-war hypothesis concerning the nature of the auroral particles and their energies was fully confirmed, with the exception that helium and oxygen ions were identified as participating in the auroral particle precipitation in addition to the protons. The nature of the near-Earth energization processes affecting auroral particles was clarified. Charged particle trajectories in various electric field geometries were modeled. The physical problems have now moved from determining the nature and geometry of the electric fields, which accelerate charged particles near the Earth, to accounting for the existence of these electric fields as a natural consequence of the solar wind's interaction with Earth. Ultimately the reward in continuing the work in auroral and magnetospheric particle dynamics will be a deeper understanding of the subtleties of classical electricity and magnetism as applied to situations not blessed with well-defined and invariant geometries
Elementary particles and particle interactions
International Nuclear Information System (INIS)
Bethge, K.; Schroeder, U.E.
1986-01-01
This book is a textbook for an introductory course of elementary particle physics. After a general introduction the symmetry principles governing the interactions of elementary particles are discussed. Then the phenomenology of the electroweak and strong interactions are described together with a short introduction to the Weinberg-Salam theory respectively to quantum chromodynamics. Finally a short outlook is given to grand unification with special regards to SU(5) and cosmology in the framework of the current understanding of the fundamental principles of nature. In the appendix is a table of particle properties and physical constants. (HSI) [de
Hilke, Hans Jürgen; Joram, Christian; CERN. Geneva
1991-01-01
Lecture 5: Detector characteristics: ALEPH Experiment cut through the devices and events - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operartion and a few ideas on the future performance. Lecture 4-pt. b Following the Scintillators. Lecture 4-pt. a : Scintillators - Used for: -Timing (TOF, Trigger) - Energy Measurement (Calorimeters) - Tracking (Fibres) Basic scintillation processes- Inorganic Scintillators - Organic Scintil - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operation and a fiew ideas on future developpement session 3 - part. b Following Calorimeters lecture 3-pt. a Calorimeters - determine energy E by total absorption of charged or neutral particles - fraction of E is transformed into measurable quantities - try to acheive sig...
International Nuclear Information System (INIS)
Samios, N.P.
1993-01-01
I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc
Population and particle decay of isobaric analog states in medium heavy nuclei
International Nuclear Information System (INIS)
Gales, S.
1980-05-01
The systematic features of proton stripping and neutron pick-up reactions to Isobaric Analog States in medium heavy nuclei are presented. The ( 3 He,d) reaction investigated at high incident energy is shown to selectively excite high-spin particle-analog states. Similarly the ( 3 He,α) reaction populates hole-analog states. The recent results related to such highly excited states in a wide range of nuclei ( 48 Ca to 208 Pb) are discussed in the framework of the DWBA theory of direct reactions with special emphasis on the treatment of unbound proton states or deeply-bound neutron hole states. The particle decay of Isobaric Analog States are investigated using the ( 3 He,d p) and ( 3 He, α p) sequential processes. The experimental method developed at Orsay (0 0 detection) for particle-particle angular correlations is presented. The advantage and the limits of such approach are illustrated by typical examples of particle decays: core-excited states, neutron particle-hole multiplets and the first observation of the proton emission of hole-analog levels. In conclusion new experimental approaches such as asymmetry measurements for analog states observed in transfer reactions or possible population of double analog states in heavy nuclei are discussed
Martin, Brian R
2017-01-01
An accessible and carefully structured introduction to Particle Physics, including important coverage of the Higgs Boson and recent progress in neutrino physics. Fourth edition of this successful title in the Manchester Physics series. Includes information on recent key discoveries including : An account of the discovery of exotic hadrons, beyond the simple quark model; Expanded treatments of neutrino physics and CP violation in B-decays; An updated account of ‘physics beyond the standard model’, including the interaction of particle physics with cosmology; Additional problems in all chapters, with solutions to selected problems available on the book’s website; Advanced material appears in optional starred sections.
International Nuclear Information System (INIS)
Prasad, R.
1984-01-01
Two previous monographs report on investigations into the extent to which a unified field theory can satisfactorily describe physical reality. The first, Unified field Theory, showed that the paths within a non-Riemannian space are governed by eigenvalue equations. The second, Fundamental Constants, show that the field tensors satisfy sets of differential equations with solutions which represent the evolution of the fields along the paths of the space. The results from the first two monographs are used in this one to make progress on the theory of elementary particles. The five chapters are as follows - Quantum mechanics, gravitation and electromagnetism are aspects of the Unified theory; the fields inside the particle; the quadratic and linear theories; the calculation of the eigenvalues and elementary particles as stable configurations of interacting fields. It is shown that it is possible to construct an internal structure theory for elementary particles. The theory lies within the framework of Einstein's programme-to identify physical reality with a specified geometrical structure. (U.K.)
International Nuclear Information System (INIS)
Miller, David J.
1987-01-01
The Conference on Position-Sensitive Detectors held at London's University College from 7-11 September highlighted the importance and the growing applications of these precision devices in many branches of science, underlining once again the high spinoff potential for techniques developed inside particle physics
International Nuclear Information System (INIS)
Mais, H.; Ripken, G.; Wrulich, A.; Schmidt, F.
1986-02-01
After a brief description of typical applications of particle tracking in storage rings and after a short discussion of some limitations and problems related with tracking we summarize some concepts and methods developed in the qualitative theory of dynamical systems. We show how these concepts can be applied to the proton ring HERA. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Miller, David J.
1987-10-15
The Conference on Position-Sensitive Detectors held at London's University College from 7-11 September highlighted the importance and the growing applications of these precision devices in many branches of science, underlining once again the high spinoff potential for techniques developed inside particle physics.
2005-01-01
While biomedicine and geoscience use grids to bring together many different sub-disciplines, particle physicists use grid computing to increase computing power and storage resources, and to access and analyze vast amounts of data collected from detectors at the world's most powerful accelerators (1 page)
Degond, Pierre; Tadmor, Eitan
2017-01-01
This volume collects ten surveys on the modeling, simulation, and applications of active particles using methods ranging from mathematical kinetic theory to nonequilibrium statistical mechanics. The contributing authors are leading experts working in this challenging field, and each of their chapters provides a review of the most recent results in their areas and looks ahead to future research directions. The approaches to studying active matter are presented here from many different perspectives, such as individual-based models, evolutionary games, Brownian motion, and continuum theories, as well as various combinations of these. Applications covered include biological network formation and network theory; opinion formation and social systems; control theory of sparse systems; theory and applications of mean field games; population learning; dynamics of flocking systems; vehicular traffic flow; and stochastic particles and mean field approximation. Mathematicians and other members of the scientific commu...
International Nuclear Information System (INIS)
Merwin, S.E.; Moeller, M.P.
1989-01-01
Nuclear Regulatory Commission (NRC) licensees are required to assess the dose to skin from a hot particle contamination event at a depth of skin of7mg/cm 2 over an area of 1 cm 2 and compare the value to the current dose limit for the skin. Although the resulting number is interesting from a comparative standpoint and can be used to predict local skin reactions, comparison of the number to existing limits based on uniform exposures is inappropriate. Most incidents that can be classified as overexposures based on this interpretation of dose actually have no effect on the health of the worker. As a result, resources are expended to reduce the likelihood that an overexposure event will occur when they could be directed toward eliminating the cause of the problem or enhancing existing programs such as contamination control. Furthermore, from a risk standpoint, this practice is not ALARA because some workers receive whole body doses in order to minimize the occurrence of hot particle skin contaminations. In this paper the authors suggest an alternative approach to controlling hot particle exposures
Energy Technology Data Exchange (ETDEWEB)
Khare, A.
1980-07-01
Current state of art in the discovery of new elementary particles is reviewed. At present, quarks and mesons are accepted as the basic constituents of matter. The charmonium model (canti-c system), and the 'open charm' are discussed. Explanations are offered for the recent discovery of the heavy lepton tau. Quark states such as the beauty and taste are also dealt with at length. The properties of the tanti-t bound system are speculated. It is concluded that the understanding of canti-c and banti-b families is facilitated by the assumption of the quarkonium model. Implications at the astrophysical level are indicated.
Collinson, Chris
1995-01-01
* Assumes no prior knowledge* Adopts a modelling approach* Numerous tutorial problems, worked examples and exercises included* Elementary topics augmented by planetary motion and rotating framesThis text provides an invaluable introduction to mechanicsm confining attention to the motion of a particle. It begins with a full discussion of the foundations of the subject within the context of mathematical modelling before covering more advanced topics including the theory of planetary orbits and the use of rotating frames of reference. Truly introductory , the style adoped is perfect for those u
Fermilab | Particle Physics Division
Diversity Education Safety Sustainability and Environment Contact Science Science Particle Physics Neutrinos Scientific Computing Research & Development Key Discoveries Benefits of Particle Physics Particle Superconducting Test Accelerator LHC and Future Accelerators Accelerators for Science and Society Particle Physics
Antonella Del Rosso
2014-01-01
These devices are designed to provide a current pulse of 5000 Amps which will in turn generate a fast magnetic pulse that steers the incoming beam into the LHC. Today, the comprehensive upgrade of the LHC injection kicker system is entering its final stages. The upgraded system will ensure the LHC can be refilled without needing to wait for the kicker magnets to cool, thus enhancing the performance of the whole accelerator. An upgraded kicker magnet in its vacuum tank, with an upgraded beam screen. The LHC is equipped with two kicker systems installed at the injection points (near points 2 and 8, see schematic diagram) where the particle beams coming from the SPS are injected into the accelerator’s orbit. Each system comprises four magnets and four pulse generators in which the field rises to 0.12 Tesla in less than 900 nanoseconds and for a duration of approximately 8 microseconds. Although the injection kickers only pulse 12 times to fill the LHC up with beam, the LHC beam circ...
Revisiting instanton corrections to the Konishi multiplet
Energy Technology Data Exchange (ETDEWEB)
Alday, Luis F. [Mathematical Institute, University of Oxford,Andrew Wiles Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG (United Kingdom); Korchemsky, Gregory P. [Institut de Physique Théorique, Université Paris Saclay, CNRS, CEA,F-91191 Gif-sur-Yvette (France)
2016-12-01
We revisit the calculation of instanton effects in correlation functions in N=4 SYM involving the Konishi operator and operators of twist two. Previous studies revealed that the scaling dimensions and the OPE coefficients of these operators do not receive instanton corrections in the semiclassical approximation. We go beyond this approximation and demonstrate that, while operators belonging to the same N=4 supermultiplet ought to have the same conformal data, the evaluation of quantum instanton corrections for one operator can be mapped into a semiclassical computation for another operator in the same supermultiplet. This observation allows us to compute explicitly the leading instanton correction to the scaling dimension of operators in the Konishi supermultiplet as well as to their structure constants in the OPE of two half-BPS scalar operators. We then use these results, together with crossing symmetry, to determine instanton corrections to scaling dimensions of twist-four operators with large spin.
Vector supersymmetric multiplets in two dimensions
International Nuclear Information System (INIS)
Khattab, Mohammad
1990-01-01
Author.The invariance of both, N=1 supersymmetric yang-Mills theory and N-1 supersymmetric off-shell Wess-Zumino model in four dimensions is proved. Dimensional reduction is then applied to obtain super Yang-Mills theory with extended supersymmetry, N=2, in two dimensions. The resulting theory is then truncated to N=1 super Yang-Mills and with further truncation, N=1/2 supersymmetry is shown to be possible. Then, using the duality transformations, we find the off-shell supersymmetry algebra is closed and that the auxiliary fields are replaced by four-rank antisymmetric tensors with Gauge symmetry. Finally, the mechanism of dimensional reduction is then applied to obtain N=2 extended off-shell supersymmetric model with two gauge vector fields
Fermilab | Science | Particle Physics
Photos and videos Latest news For the media Particle Physics Neutrinos Fermilab and the LHC Dark matter initiatives Research and development Key discoveries Benefits of particle physics Particle Accelerators society Particle Physics 101 Science of matter, energy, space and time How particle physics discovery
International Nuclear Information System (INIS)
Gaisser, T.K.; Shafi, Q.; Barr, S.M.; Seckel, D.; Rusjan, E.; Fletcher, R.S.
1991-01-01
This report discusses research of professor at Bartol research institute in the following general areas: particle phenomenology and non-accelerator physics; particle physics and cosmology; theories with higher symmetry; and particle astrophysics and cosmology
Gritti, Fabrice; Omamogho, Jesse; Guiochon, Georges
2011-10-07
The recent successful breakthrough of sub-3 μm shell particles in HPLC has triggered considerable research efforts toward the design of new brands of core-shell particles. We investigated the mass transfer mechanism of a few analytes in narrow-bore columns packed with prototype 1.7 μm shell particles, made of 1.0, 1.2, and 1.4 μm solid nonporous cores surrounded by porous shells 350, 250, and 150 nm thick, respectively. Three probe solutes, uracil, naphthalene, and insulin, were chosen to assess the kinetic performance of these columns. Inverse size exclusion chromatography, peak parking experiments, and the numerical integration of the experimental peak profiles were carried out in order to measure the external, internal, and total column porosities, the true bulk diffusion coefficients of these analytes, the height equivalent to a theoretical plate, the longitudinal diffusion term, and the trans-particle mass transfer resistance term. The residual eddy diffusion term was measured by difference. The results show the existence of important trans-column velocity biases (7%) possibly due to the presence of particle multiplets in the slurry mixture used during the packing process. Our results illustrates some of the difficulties encountered by scientists preparing and packing shell particles into narrow-bore columns. Copyright © 2011 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Okun, L.B.
1991-01-01
This book presents papers on elementary particle physics, relations between various particles, and the connections between particle physics with other branches of physics. The papers include: Contemporary status and prospects of high-energy physics; Particle physics prospects; and High energy physics
Mittal, K L
2015-01-01
The book provides a comprehensive and easily accessible reference source covering all important aspects of particle adhesion and removal. The core objective is to cover both fundamental and applied aspects of particle adhesion and removal with emphasis on recent developments. Among the topics to be covered include: 1. Fundamentals of surface forces in particle adhesion and removal.2. Mechanisms of particle adhesion and removal.3. Experimental methods (e.g. AFM, SFA,SFM,IFM, etc.) to understand particle-particle and particle-substrate interactions.4. Mechanics of adhesion of micro- and n
Review of particle properties. Particle Data Group
International Nuclear Information System (INIS)
1978-04-01
This review of the properties of leptons, mesons, and baryons is an updating of Review of Particle Properties, Particle Data Group [Rev. Mod. Phys. 48 (1976) No. 2, Part II; and Supplement, Phys. Lett. 68B (1977) 1]. Data are evaluated, listed, averaged, and summarized in tables. Numerous tables, figures, and formulae of interest to particle physicists are also included. A data booklet is available
Menmuir, S.; Kuldkepp, M.; Rachlew, E.
2006-10-01
An absolute intensity calibrated 0.5 m spectrometer with optical multi-channel analyser detector was used to observe the visible-UV radiation from the plasma in the EXTRAP T2R reversed field pinch experiment. Spectral lines were identified indicating the presence of oxygen, chromium, iron and molybdenum impurities in the hydrogen plasma. Certain regions of interest were examined in more detail and at different times in the plasma discharge. Impurity concentration calculations were made using the absolute intensities of lines of OIV and OV measured at 1-2 ms into the discharge generating estimates of the order of 0.2% of ne in the central region rising to 0.7% of ne at greater radii for OIV and 0.3% rising to 0.6% for OV. Edge electron temperatures of 0.5-5 eV at electron densities of 5-10×1011 cm-3 were calculated from the measured relative intensities of hydrogen Balmer lines. The absolute intensities of hydrogen lines and of multiplets of neutral chromium and molybdenum were used to determine particle fluxes (at 4-5 ms into the plasma) of the order 1×1016, 7×1013 and 3×1013 particles cm-2 s-1, respectively.
Energy Technology Data Exchange (ETDEWEB)
Saudinos, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1962-07-01
Inelastic scattering of medium energy a particles by nuclei is known to excite preferentially levels of collective character. We have studied the scattering of isotopically enriched targets of Ca, Fe, Ni, Cu, Zn. In part I, we discuss the theoretical features of the interaction. In part II, we describe the experimental procedure. Results are presented and analysed in part III. {alpha} particles scattering by Ca{sup 40} is showed to excite preferentially odd parity levels. In odd nuclei we have observed multiplets due to the coupling of the odd nucleon with the even-even core vibrations. For even-even nuclei, a few levels are excited with lower cross-sections between the well-known first 2{sup +} and 3{sup -} states. Some could be members of the two phonon quadrupole excitation and involve a double nuclear excitation process. (author) [French] On sait que la diffusion inelastique des particules alpha de moyenne energie excite preferentiellement des niveaux de caractere collectif. Nous avons etudie la diffusion des particules alpha de 44 MeV du cyclotron de Saclay par des isotopes separes de Ca, Fe, Ni, Cu, Zn. Dans la premiere partie nous exposons les theories de cette interaction. Dans la seconde nous decrivons le systeme experimental. Les resultats sont donnes dans la troisieme partie. Nous montrons que les niveaux excites preferentiellement pour {sup 40}Ca par diffusion ({alpha},{alpha}') sont de parite negative. Dans les noyaux pair-impair nous avons observe des multiplets dus au couplage du nucleon celibataire avec les vibrations du coeur pair-pair. Pour les noyaux pair-pair nous avons pu etudier entre le premier niveau 2{sup +} et le niveau 3{sup -} deja bien connus certains etats plus faiblement excites. Il semble qu'ils sont dus a une excitation quadrupolaire a deux phonons et impliquent un processus de double excitation nucleaire. (auteur)
Accelerators of atomic particles
International Nuclear Information System (INIS)
Sarancev, V.
1975-01-01
A brief survey is presented of accelerators and methods of accelerating elementary particles. The principle of collective accelerating of elementary particles is clarified and the problems are discussed of its realization. (B.S.)
Elementary particles and cosmology
International Nuclear Information System (INIS)
Audouze, J.; Paty, M.
2000-01-01
The universe is the most efficient laboratory of particle physics and the understanding of cosmological processes implies the knowledge of how elementary particles interact. This article recalls the mutual influences between on the one hand: astrophysics and cosmology and on the other hand: nuclear physics and particle physics. The big-bang theory relies on nuclear physics to explain the successive stages of nucleo-synthesis and the study of solar neutrinos has led to discover new aspects of this particle: it is likely that neutrinos undergo oscillations from one neutrino type to another. In some universe events such as the bursting of a super-nova, particles are released with a kinetic energy that would be impossible to reach on earth with a particle accelerator. These events are become common points of interest between astrophysicists and particle physicists and have promoted a deeper cooperation between astrophysics and elementary particle physics. (A.C.)
Particle Physics Education Sites
back to home page Particle Physics Education Sites quick reference Education and Information - National Laboratory Education Programs - Women and Minorities in Physics - Other Physics Sites - Physics Alliance - Accelerators at National Laboratories icon Particle Physics Education and Information sites: top
Energy Technology Data Exchange (ETDEWEB)
Yost, G P; Barnett, R M; Hinchliffe, I; Lynch, G R; Rittenberg, A; Ross, R R; Suzuki, M; Trippe, T G; Wohl, C G; Armstrong, B
1988-04-14
This review of the properties of gauge bosons, leptons, mesons, and baryons is an updating of the Review of Particle Properties, Particle Data Group (Phys. Lett. 170B (1986)). Data are evaluated, listed, averaged, and summarized in tables. We continue the more orderly set of particle names implemented in the 1986 edition. Numerous tables, figures, and formulae of interest to particle physicists are also included. A data booklet is available.
Lederman, Leon M
2013-01-01
On July 4, 2012, the long-sought Higgs Boson--aka "the God Particle"--was discovered at the world's largest particle accelerator, the LHC, in Geneva, Switzerland. On March 14, 2013, physicists at CERN confirmed it. This elusive subatomic particle forms a field that permeates the entire universe, creating the masses of the elementary particles that are the basic building blocks of everything in the known world--from viruses to elephants, from atoms to quasars.
Particle physics and cosmology
International Nuclear Information System (INIS)
Schramm, D.N.; Turner, M.S.
1982-06-01
work is described in these areas: cosmological baryon production; cosmological production of free quarks and other exotic particle species; the quark-hadron transition in the early universe; astrophysical and cosmological constraints on particle properties; massive neutrinos; phase transitions in the early universe; and astrophysical implications of an axion-like particle
Particle-nuclear intersections
International Nuclear Information System (INIS)
Anon.
1994-01-01
With the traditional distinctions between particle and nuclear physics becoming increasing blurred, the Fifth Conference on the Intersections of Particle and Nuclear Physics, held from May 31 to June 6 in St. Petersburg, Florida, brought together particle and nuclear physicists to discuss common research efforts and to define and plan a united approach
International Nuclear Information System (INIS)
Trippe, T.G.; Barbaro-Galtieri, A.; Kelly, R.L.; Rittenberg, A.; Rosenfeld, A.H.; Yost, G.P.; Barash-Schmidt, N.; Bricman, C.; Hemingway, R.J.; Losty, M.J.; Roos, M.; Chaloupka, V.; Armstrong, B.
1976-01-01
This review of the properties of leptons, mesons, and baryons is an updating of Review of Particle Properties, Particle Data Group [Phys. Letters 50B, No.1 (1974), and Supplement, Rev. Mod. Phys. 47 (1975) 535]. Data are evaluated, listed, averaged, and summarized in tables. Numerous tables, figures, and formulae of interest to particle physicists are also included. A data booklet is available
Energy Technology Data Exchange (ETDEWEB)
Hellman, Hal
1970-01-01
This booklet tells how scientists observe the particles and electromagnetic radiation that emerges from an atomic nucleus. The equipment used falls into two general categories: counters which count each particle as it passes by, and track detectors, which make a photographic record of the particle's track.
Study of particle swarm optimization particle trajectories
CSIR Research Space (South Africa)
Van den Bergh, F
2006-01-01
Full Text Available . These theoretical studies concentrate mainly on simplified PSO systems. This paper overviews current theoretical studies, and extend these studies to investigate particle trajectories for general swarms to include the influence of the inertia term. The paper also...
Light scattering by cosmic particles
Hovenier, J.W.; Min, M.
2008-01-01
We define cosmic particles as particles outside the Earth. Two types of cosmic particles can be distinguished, namely liquid and solid particles. The solid particles are often called grains or cosmic dust particles. Cosmic particles occur in a great variety of astronomical objects and environments.
Slowing of charged particles by particle methods
International Nuclear Information System (INIS)
Mercier, B.
1985-03-01
We review some facts about particle methods for solving linear hyperbolic equations. We show how one gets an evaluation of integral quantities like: ∫ u(x,t) zeta(x,t) dxdt where u denotes the solution and zeta an arbitrary weight function. Then, we apply the method to the equation describing charged particle transport in a plasma with emphasis on the evaluation of energy deposition on ions and electrons [fr
International Nuclear Information System (INIS)
Ranft, G.; Ranft, J.
1977-01-01
In this part the subject is covered under the following headings, methods for producing high-energy particles; interaction of high-energy particles with matter; methods for the detection of high-energy particles; symmetry properties and conservation laws; quantum number and selection rules; theorem of scattering behaviour at asymptotically high energies; statistical methods in elementary particle physics; interaction of high-energy particles with nuclei; relations of high-energy physics to other branches of science and its response to engineering. Intended as information on high-energy physics for graduate students and research workers familiar with the fundamentals of classical and quantum physics
International Nuclear Information System (INIS)
Montanet, L.; Gieselmann, K. Technical Associate; Barnett, R.M.; Groom, D.E.; Trippe, T.G.; Wohl, C.G.; Armstrong, B. Technical Associate; Wagman, G.S. Technical Associate; Murayama, H.; Stone, J.; Hernandez, J.J.; Porter, F.C.; Morrison, R.J.; Manohar, A.; Aguilar-Benitez, M.; Caso, C.; Lantero, P. Technical Associate; Crawford, R.L.; Roos, M.; Toernqvist, N.A.; Hayes, K.G.; Hoehler, G.
1994-01-01
This biennial review summarizes much of Particle Physics. Using data from previous editions, plus 2300 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, monopoles, 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
Fluidization of spherocylindrical particles
Mahajan, Vinay V.; Nijssen, Tim M. J.; Fitzgerald, Barry W.; Hofman, Jeroen; Kuipers, Hans; Padding, Johan T.
2017-06-01
Multiphase (gas-solid) flows are encountered in numerous industrial applications such as pharmaceutical, food, agricultural processing and energy generation. A coupled computational fluid dynamics (CFD) and discrete element method (DEM) approach is a popular way to study such flows at a particle scale. However, most of these studies deal with spherical particles while in reality, the particles are rarely spherical. The particle shape can have significant effect on hydrodynamics in a fluidized bed. Moreover, most studies in literature use inaccurate drag laws because accurate laws are not readily available. The drag force acting on a non-spherical particle can vary considerably with particle shape, orientation with the flow, Reynolds number and packing fraction. In this work, the CFD-DEM approach is extended to model a laboratory scale fluidized bed of spherocylinder (rod-like) particles. These rod-like particles can be classified as Geldart D particles and have an aspect ratio of 4. Experiments are performed to study the particle flow behavior in a quasi-2D fluidized bed. Numerically obtained results for pressure drop and bed height are compared with experiments. The capability of CFD-DEM approach to efficiently describe the global bed dynamics for fluidized bed of rod-like particles is demonstrated.
Monosodium titanate particle characterization
International Nuclear Information System (INIS)
Chandler, G.T.; Hobbs, D.T.
1993-01-01
A characterization study was performed on monosodium titanate (MST) particles to determine the effect of high shear forces expected from the In-Tank Precipitation (ITP) process pumps on the particle size distribution. The particles were characterized using particle size analysis and scanning electron microscopy (SEM). No significant changes in particle size distributions were observed between as-received MST and after 2--4 hours of shearing. Both as-received and sheared MST particles contained a large percentage of porosity with pore sizes on the order of 500 to 2,000 Angstroms. Because of the large percentage of porosity, the overall surface area of the MST is dominated by the internal surfaces. The uranium and plutonium species present in the waste solution will have access to both interior and exterior surfaces. Therefore, uranium and plutonium loading should not be a strong function of MST particle size
Lecture II. Charmed particle spectroscopy
International Nuclear Information System (INIS)
Anon.
1978-01-01
The discussion of charmed particle spectroscopy covers the particle properties and interrelations from a charmed quark composition point of view including SU(4)-symmetry generalities, mesons, baryons, charmed particle masses, and decays of charmed particles. 6 references
Fox, Robert V.; Zhang, Fengyan; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin
2016-06-21
Single source precursors or pre-copolymers of single source precursors are subjected to microwave radiation to form particles of a I-III-VI.sub.2 material. Such particles may be formed in a wurtzite phase and may be converted to a chalcopyrite phase by, for example, exposure to heat. The particles in the wurtzite phase may have a substantially hexagonal shape that enables stacking into ordered layers. The particles in the wurtzite phase may be mixed with particles in the chalcopyrite phase (i.e., chalcopyrite nanoparticles) that may fill voids within the ordered layers of the particles in the wurtzite phase thus produce films with good coverage. In some embodiments, the methods are used to form layers of semiconductor materials comprising a I-III-VI.sub.2 material. Devices such as, for example, thin-film solar cells may be fabricated using such methods.
Stefania Pandolfi
2016-01-01
The LHCb collaboration announces the observation of four “exotic” particles from its analysis of the LHC data. The LHCb experimental cavern. On 28 June, the LHCb collaboration reported the observation of three new "exotic" particles and confirmation of the existence of a fourth one in data from the LHC. These particles each appear to be formed by four quarks (the fundamental constituents of the matter inside all the atoms of the universe): two quarks and two antiquarks (that is, a tetraquark). Due to their non-standard quark content, the newly observed particles have been included in the broad category of so-called exotic particles, although their exact theoretical interpretation is still under study. The quark model, proposed by Murray Gell-Mann and George Zweig in 1964, is considered to be the most valid scheme for the classification of hadrons (all the composite particles) that has been fou...
Venter, Gerhard; Sobieszczanski-Sobieski Jaroslaw
2002-01-01
The purpose of this paper is to show how the search algorithm known as particle swarm optimization performs. Here, particle swarm optimization is applied to structural design problems, but the method has a much wider range of possible applications. The paper's new contributions are improvements to the particle swarm optimization algorithm and conclusions and recommendations as to the utility of the algorithm, Results of numerical experiments for both continuous and discrete applications are presented in the paper. The results indicate that the particle swarm optimization algorithm does locate the constrained minimum design in continuous applications with very good precision, albeit at a much higher computational cost than that of a typical gradient based optimizer. However, the true potential of particle swarm optimization is primarily in applications with discrete and/or discontinuous functions and variables. Additionally, particle swarm optimization has the potential of efficient computation with very large numbers of concurrently operating processors.
International Nuclear Information System (INIS)
Sternheimer, J.
1983-01-01
This Note offers a new point of view on particle masses. It is shown that they are distributed following a musical scale, the chromatic tempered scale -for stable particles- subdivided into microintervals including unstable particles. A theoretical explanation, based on causality, allows one also to calculate their global distribution along the mass scale, in agreement with experiment, and indicating the existence of ''musical'' laws in the vibratory organisation of matter [fr
Low energy particle composition
International Nuclear Information System (INIS)
Gloeckler, G.
1975-01-01
More than 50 papers presented at this Conference dealt with the composition of low energy particles. The topics can be divided roughly into two broad categories. The first is the study of the energy spectra and composition of the steady or 'quiet-time' particle flux, whose origin is at this time unknown. The second category includes the study of particles and photons which are associated with solar flares or active regions on the sun. (orig.) [de
Energy Technology Data Exchange (ETDEWEB)
Sternheimer, J.
1983-12-12
This note offers a new point of view on particle masses. It is shown that they are distributed following a musical scale, the chromatic tempered scale -for stable particles- subdivided into microintervals including unstable particles. A theoretical explanation, based on causality, allows one also to calculate their global distribution along the mass scale, in agreement with experiment, and indicating the existence of ''musical'' laws in the vibratory organisation of matter.
International Nuclear Information System (INIS)
Bricman, C.; Dionisi, C.; Hemingway, R.J.; Mazzucato, M.; Montanet, L.; Barash-Schmidt, N.; Crawford, R.C.; Roos, M.; Barbaro-Galtieri, A.; Horne, C.P.; Kelly, R.L.; Losty, M.J.; Rittenberg, A.; Trippe, T.G.; Yost, G.P.; Armstrong, B.
1978-01-01
This review of the properties of leptons, mesons, and baryons is an updating of Review of Particle Properties, Particle Data Group [Rev. Mod. Phys. 48 (1976) No. 2, Part II; and Supplement, Phys. Lett. 68B (1977) 1]. Data are evaluated, listed, averaged, and summarized in tables. Numerous tables, figures, and formulae of interest to particle physicists are also included. A data booklet is available. (Auth.)
Condensed elementary particle matter
International Nuclear Information System (INIS)
Kajantie, K.
1996-01-01
Quark matter is a special case of condensed elementary particle matter, matter governed by the laws of particle physics. The talk discusses how far one can get in the study of particle matter by reducing the problem to computations based on the action. As an example the computation of the phase diagram of electroweak matter is presented. It is quite possible that ultimately an antireductionist attitude will prevail: experiments will reveal unpredicted phenomena not obviously reducible to the study of the action. (orig.)
Particle correlations at ALICE
Energy Technology Data Exchange (ETDEWEB)
Erazmus, B.; Lednicky, R.; Lyuboshitz, V.; Martin, L.; Mikhailov, K.; Pluta, J.; Sinyukov, Yu.; Stavinsky, A.; Werner, K
1998-12-31
The ability of the ALICE detector for determination of the space-time characteristics of particle production in heavy-ion collisions at LHC from measurements of the correlation functions of identical and non-identical particles at small relative velocities is discussed. The possibility to use the correlations of non-identical particles for a direct determination of the delays in emission of various particle species at time scales as small as 10{sup -23} s is demonstrated. The influence of the multi-boson effects on pion multiplicities, single-pion spectra and two-pion correlation functions is discussed. (author) 63 refs.
Kress, Thomas
2002-01-01
Particle correlations are extensively studied to obtain information about the dynamics of hadron production. From 1989 to 2000 the four LEP collaborations recorded more than 16 million hadronic Z0 decays and several thousand W+W- events. In Z0 decays, two-particle correlations were analysed in detail to study Bose-Einstein and Fermi-Dirac correlations for various particle species. In fully-hadronic W+W- decays, particle correlations were used to study whether the two W bosons decay independently. A review of selected results is presented.
DEFF Research Database (Denmark)
Zhang, Chen; Vasilevskis, Sandijs; Kozlowski, Bartosz
Particle image velocimetry (PIV) is a non-intrusive, whole filed optical method providing instantaneous velocity information in fluids. The flow is seeded with tracer particles. The particles are illuminated in the target area with a light sheet at least twice within a short time interval....... The camera images the target area and captures each light pulse in separate image frames. The displacement of the particle between the light pulses can be used to determine the velocity vectors. This guideline introduces the principle of the PIV system and the system configuration. The measurement procedure...
International Nuclear Information System (INIS)
Hikasa, K.; Hagiwara, K.; Kawabata, S.; Barnett, R.M.; Groom, D.E.; Trippe, T.G.; Wohl, C.G.; Yost, G.P.; Armstrong, B. Technical Associate; Wagman, G.S. Technical Associate; Stone, J.; Porter, F.C.; Morrison, R.J.; Cutkosky, R.E.; Montanet, L.; Gieselmann, K. Technical Associate; Aguilar-Benitez, M.; Caso, C.; Crawford, R.L.; Roos, M.; Toernqvist, N.A.; Hayes, K.G.; Hoehler, G.; Manley, D.M.
1992-01-01
In this Review, 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, the top quark, heavy neutrinos, monopoles, 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 other sections of this full Review
International Nuclear Information System (INIS)
Marciano, W.J.
1984-12-01
The present state of the art in elementary particle theory is reviewed. Topics include quantum electrodynamics, weak interactions, electroweak unification, quantum chromodynamics, and grand unified theories. 113 references
Particle physics experiments 1983
International Nuclear Information System (INIS)
Stuart, G.W.
1983-01-01
The report describes work carried out in 1983 on experiments approved by the Particle Physics Experiments Selection Panel. The contents consist of unedited contributions from each experiment. (author)
Particle Physics & Astrophysics (PPA)
Federal Laboratory Consortium — Scientists at SLAC's Particle Physics and Astrophysics develop and utilize unique instruments from underground to outer space to explore the ultimate laws of nature...
Dirac particle in a magnetic field: Symmetries and their breaking by monopole singularities
International Nuclear Information System (INIS)
Goldhaber, A.S.
1977-01-01
Some rules governing motion of a charged particle obeying the Dirac equation are assembled, including exact helicity conservation for scattering on an arbitrary finite magnetic field configuration. The singularity at the location of a magnetic monopole invalidates the derivation of the rules mentioned, leaving the Dirac Hamiltonian H undefined for the lowest angular momentum state of the electron in the field of the pole. Specifying the behavior of H under the discrete P, T, and C symmetries determines it almost uniquely. One result is that H may possess a bound state of zero energy, contrary to assertions in early papers on the subject. Zero-energy bound states which violate the superselection rule for electric charge are also studied, including one which is the point limit of a solution for a fermion multiplet interacting with a finite-energy soliton monopole. Implications of such a bound state for second quantization have been considered previously by others and are further analyzed here. The suggestion that monopoles may possess half-integral fermion number is shown to be unwarranted by present evidence
Particle Swarm Optimisation with Spatial Particle Extension
DEFF Research Database (Denmark)
Krink, Thiemo; Vesterstrøm, Jakob Svaneborg; Riget, Jacques
2002-01-01
In this paper, we introduce spatial extension to particles in the PSO model in order to overcome premature convergence in iterative optimisation. The standard PSO and the new model (SEPSO) are compared w.r.t. performance on well-studied benchmark problems. We show that the SEPSO indeed managed...
Violation of Particle Anti-particle Symmetry
CERN. Geneva
2001-01-01
Symmetry is a fundamental concept which can be found in the whole range of human activities e. g. from arts to science. The beauty of a statues is often related to its symmetric form. In physics, all the laws are related to some sort of symmetry. Equally important is a small breakdown ofsymmetry. Even for the case of a statue, its beauty might be enhanced by introducing small distortions. In this course, we investigate the role symmetry in the world of elementary particles. Some symmetries found there are very similar to those which can be seen in our daily life, while others are more exotic and related to the quantum nature of the elementary particles. Our particular focus ismade on symmetry and its violation between the matter and anti-matter, known as CP violation. It is experimentally well established that particleand anti-particle behave a tiny bit differently in the world of elementary particles. We discuss how this would be explained and how we can extendour knowledge. Evolution of our universe is stro...
International Nuclear Information System (INIS)
Burr, K.J.
1979-01-01
A specification is given for an apparatus to provide a completely automatic testing cycle to determine the proportion of particles of less than a predetermined size in one of a number of fluid suspensions. Monitoring of the particle concentration during part of the process can be carried out by an x-ray source and detector. (U.K.)
Stefanovich, Eugene
2018-01-01
This book introduces notation, terminology, and basic ideas of relativistic quantum theories. The discussion proceeds systematically from the principle of relativity and postulates of quantum logics to the construction of Poincaré invariant few-particle models of interaction and scattering. It is the first of three volumes formulating a consistent relativistic quantum theory of interacting charged particles.
back to history page Back Particle Physics Timeline For over two thousand years people have thought the Standard Model. We invite you to explore this history of particle physics with a focus on the : Quantum Theory 1964 - Present: The Modern View (the Standard Model) back to history page Back Sections of
Nagendra Prakash, Vivek
2013-01-01
This thesis deals with the broad topic of particles in turbulence, which has applications in a diverse number of fields. A vast majority of fluid flows found in nature and in the industry are turbulent and contain dispersed elements. In this thesis, I have focused on light particles (air bubbles in
Particle physics instrumentation
International Nuclear Information System (INIS)
Riegler, W.
2011-01-01
This report summarizes a series of three lectures aimed at giving an overview of basic particle detection principles, the interaction of particles with matter, the application of these principles in modern detector systems, as well techniques to read out detector signals in high-rate experiments. (author)
Particles, contacts, bulk behavior
Luding, Stefan; Tomas, J.
2014-01-01
Granular matter consists of discrete “particles”. These can be separate sand-grains, agglomerates (made of many primary particles), or solid materials like rock, composites, or metal-alloys—all with particulate inhomogeneous, possibly anisotropic micro-structure. Particles can be as small as
Particle Astrophysics of Neutrinos
Indian Academy of Sciences (India)
Amol Dighe
Energy spectra of neutrino sources. ASPERA. Page 4. Some unique features of neutrinos. The second most abundant particles in the universe. Cosmic microwave background photons: 400 / cm3. Cosmic background neutrinos: 330 / cm3. The lightest massive particles. A million times lighter than the electron. No direct mass ...
International Nuclear Information System (INIS)
Salam, A.
1985-09-01
Opening remarks at the Fourth Marcel Grossman Meeting, 17-21 June 1985, in Rome, Italy, are reported. The meeting was concerned with the symbiosis of cosmology and particle physics. Numerous connections between work in particle physics and cosmology, in both experimental and theoretical areas, are pointed out
International Nuclear Information System (INIS)
Drell, S.D.
1978-01-01
The concept of elementary constituents or ultimate building blocks of nature in recent years is reviewed. The quark hypothesis, neutrinos, color, hard collisions, psi and other recent resonances, flavor, quantum chromodynamics, the tau particle, and particle structure are among the ideas considered. 22 references
International Nuclear Information System (INIS)
Gottfried, K.; Weisskopf, V.F.
1984-01-01
This volume elucidates basic and well-established concepts of particle physics for the autodidact who is curious about recent developments in fundamental physics. Elementary quantum mechanics is a background must. Contents, abridged: The evolution of the particle concept before the advent of quantum mechanics. Nonrelativistic quantum mechanics and atomic physics. Relativistic quantum theory. Nuclear phenomena. Subnuclear phenomena. Index
Energy Technology Data Exchange (ETDEWEB)
Kearns, Edward [Boston Universiy
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.
International Nuclear Information System (INIS)
Wollnik, H.
1987-01-01
Suitable for both the specialist and non-specialist, this book develops all statements from first principles. Key chapters of the book focus upon how to design particle-optical systems, the systematics of image abberations, the effects of fringing fields, systematics of beams, and solutions for particle-optical systems. An undergraduate background in physics and mathematics is required for this work
Introduction to particle physics
International Nuclear Information System (INIS)
Zitoun, R.
2000-01-01
This book proposes an introduction to particle physics that requires only a high-school level mathematical knowledge. Elementary particles (leptons, quarks, bosons) are presented according to a modern view taking into account of their symmetries and interactions. The author shows how physicists have elaborated the standard model and what are its implications in cosmology. (J.S.)
Microchip Coulter particle counter
DEFF Research Database (Denmark)
Larsen, Ulrik Darling; Blankenstein, Gert; Branebjerg, J.
1997-01-01
This paper presents a micro device employing the Coulter principle for counting and sizing of living cells and particles in liquid suspension. The microchip Coulter particle counter (μCPC) has been employed in a planar silicon structure covered with glass, which enables detailed observation during...
Interactive Terascale Particle Visualization
Ellsworth, David; Green, Bryan; Moran, Patrick
2004-01-01
This paper describes the methods used to produce an interactive visualization of a 2 TB computational fluid dynamics (CFD) data set using particle tracing (streaklines). We use the method introduced by Bruckschen et al. [2001] that pre-computes a large number of particles, stores them on disk using a space-filling curve ordering that minimizes seeks, and then retrieves and displays the particles according to the user's command. We describe how the particle computation can be performed using a PC cluster, how the algorithm can be adapted to work with a multi-block curvilinear mesh, and how the out-of-core visualization can be scaled to 296 billion particles while still achieving interactive performance on PG hardware. Compared to the earlier work, our data set size and total number of particles are an order of magnitude larger. We also describe a new compression technique that allows the lossless compression of the particles by 41% and speeds the particle retrieval by about 30%.
Hanley, P
2000-01-01
Particle physics attracts many students who hear of news from CERN or elsewhere in the media. This article examines which current A-level syllabuses include which bits of particle physics and surveys the many different types of resource available to teachers and students. (0 refs).
International Nuclear Information System (INIS)
Harris, J.
1986-01-01
The book on particles, imaging and nuclei is one of the Background Readers for the Revised Nuffield Advanced Physics course. The contents contain five educational articles, which extend concepts covered in the course and examine recent developments in physics. Four of the articles on:- particles and the forces of nature, radioisotopes, lasers probe the atomic nucleus, and nuclear history, are indexed separately. (UK)
Energy Technology Data Exchange (ETDEWEB)
Elizondo-Decanini, Juan M.
2017-08-29
A compact particle accelerator having an input portion configured to receive power to produce particles for acceleration, where the input portion includes a switch, is provided. In a general embodiment, a vacuum tube receives particles produced from the input portion at a first end, and a plurality of wafer stacks are positioned serially along the vacuum tube. Each of the plurality of wafer stacks include a dielectric and metal-oxide pair, wherein each of the plurality of wafer stacks further accelerate the particles in the vacuum tube. A beam shaper coupled to a second end of the vacuum tube shapes the particles accelerated by the plurality of wafer stacks into a beam and an output portion outputs the beam.
Energy Technology Data Exchange (ETDEWEB)
Zhang, Boning [Univ. of Colorado, Boulder, CO (United States); Herbold, Eric B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Homel, Michael A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Regueiro, Richard A. [Univ. of Colorado, Boulder, CO (United States)
2015-12-01
An adaptive particle fracture model in poly-ellipsoidal Discrete Element Method is developed. The poly-ellipsoidal particle will break into several sub-poly-ellipsoids by Hoek-Brown fracture criterion based on continuum stress and the maximum tensile stress in contacts. Also Weibull theory is introduced to consider the statistics and size effects on particle strength. Finally, high strain-rate split Hopkinson pressure bar experiment of silica sand is simulated using this newly developed model. Comparisons with experiments show that our particle fracture model can capture the mechanical behavior of this experiment very well, both in stress-strain response and particle size redistribution. The effects of density and packings o the samples are also studied in numerical examples.
International Nuclear Information System (INIS)
Xu Hui; Yan Feng; Tierno, Pietro; Marczewski, Dawid; Goedel, Werner A
2005-01-01
Wetting of a solid surface by a liquid is dramatically impeded if either the solid or the liquid is decorated by particles. Here it is shown that in the case of contact between two liquids the opposite effect may occur; mixtures of a hydrophobic liquid and suitable particles form wetting layers on a water surface though the liquid alone is non-wetting. In these wetting layers, the particles adsorb to, and partially penetrate through, the liquid/air and/or the liquid/water interface. This formation of wetting layers can be explained by the reduction in total interfacial energy due to the replacement of part of the fluid/fluid interfaces by the particles. It is most prominent if the contact angles at the fluid/fluid/particle contact lines are close to 90 0
Fermilab | Science | Particle Physics | Benefits of Particle Physics
Photos and videos Latest news For the media Particle Physics Neutrinos Fermilab and the LHC Dark matter initiatives Research and development Key discoveries Benefits of particle physics Particle Accelerators society Particle Physics 101 Science of matter, energy, space and time How particle physics discovery
International Nuclear Information System (INIS)
Richards, J.A.
1977-01-01
A linear particle accelerator which provides a pulsed beam of charged particles of uniform energy is described. The accelerator is in the form of an evacuated dielectric tube, inside of which a particle source is located at one end of the tube, with a target or window located at the other end of the dielectric tube. Along the length of the tube are externally located pairs of metal plates, each insulated from each other in an insulated housing. Each of the plates of a pair are connected to an electrical source of voltage of opposed polarity, with the polarity of the voltage of the plates oriented so that the plate of a pair, nearer to the particle source, is of the opposed polarity to the charge of the particle emitted by the source. Thus, a first plate about the tube located nearest the particle source, attracts a particle which as it passes through the tube past the first plate is then repelled by the reverse polarity of the second plate of the pair to continue moving towards the target
International Nuclear Information System (INIS)
Hagen, R.D.
1975-01-01
A device for detecting the emission of charged particles from a specimen is described. The specimen is placed within an accumulator means which statically accumulates any charged particles emitted from the specimen. The accumulator means is pivotally positioned between a first capacitor plate having a positive electrical charge and a second capacitor plate having a negative electrical charge. The accumulator means is attracted to one capacitor plate and repelled from the other capacitor plate by an amount proportional to the amount and intensity of charged particles emitted by the specimen. (auth)
Cosmology and particle physics
International Nuclear Information System (INIS)
Barrow, J.D.
1982-01-01
A brief overview is given of recent work that integrates cosmology and particle physics. The observational data regarding the abundance of matter and radiation in the Universe is described. The manner in which the cosmological survival density of stable massive particles can be calculated is discussed along with the process of cosmological nucleosynthesis. Several applications of these general arguments are given with reference to the survival density of nucleons, neutrinos and unconfined fractionally charge particles. The use of nucleosynthesis to limit the number of lepton generations is described together with the implications of a small neutrino mass for the origin of galaxies and clusters. (Auth.)
International Nuclear Information System (INIS)
Bhattacharya, T.; Willenbrock, S.
1993-01-01
We propose returning to the definition of the width of a particle in terms of the pole in the particle's propagator. Away from thresholds, this definition of width is equivalent to the standard perturbative definition, up to next-to-leading order; however, near a threshold, the two definitions differ significantly. The width as defined by the pole position provides more information in the threshold region than the standard perturbative definition and, in contrast with the perturbative definition, does not vanish when a two-particle s-wave threshold is approached from below
International Nuclear Information System (INIS)
Arianer, J.
1997-01-01
This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.)
Cosmology and particle physics
Energy Technology Data Exchange (ETDEWEB)
Steigman, G [California Univ., Santa Barbara (USA). Inst. for Theoretical Physics; Bartol Research Foundation, Newark, Delaware (USA))
1982-01-29
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.
Particle physics and cosmology
International Nuclear Information System (INIS)
Srednicki, M.
1990-01-01
At least eighty percent of the mass of the universe consists of some material which, unlike ordinary matter, neither emits nor absorbs light. This book collects key papers related to the discovery of this astonishing fact and its profound implications for astrophysics, cosmology, and the physics of elementary particles. The book focusses on the likely possibility that the dark matter is composed of an as yet undiscovered elementary particle, and examines the boundaries of our present knowledge of the properties such a particle must possess. (author). refs.; figs.; tabs
Elementary particle interactions
International Nuclear Information System (INIS)
Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Read, K.; Ward, B.F.L.
1992-10-01
Work continues on strange particle production in weak interactions using data from a high-energy neutrino exposure in a freon bubble chamber. Meson photoproduction has also consumed considerable effort. Detector research and development activities have been carried out
Particle physics experiments 1989
International Nuclear Information System (INIS)
Bairstow, R.
1990-01-01
This report describes work carried out in 1989 on experiments approved by the Particle Physics Experiments Selection Panel of Rutherford Appleton Laboratory. The contents consist of unedited contributions from each experiment. (author)
African Journals Online (AJOL)
process of language acquisition on the basis of linguistic evidence the child is exposed to. ..... particle verbs are recognized in language processing differs from the way morphologically ..... In Natural Language and Linguistic Theory 11.
Particle physics experiments 1987
International Nuclear Information System (INIS)
Stuart, G.W.
1988-01-01
This report describes work carried out in 1987 on experiments approved by the Particle Physics Experiments Selection Panel (United Kingdom). The contents consist of unedited contributions from each experiment. (author)
International Nuclear Information System (INIS)
Stuart, G.W.
1986-01-01
The report of the Rutherford Appleton Laboratory describes the work carried out in 1985 on experiments approved by the Particle Physics Experiments Selection Panel. The contents consist of unedited contributions from each experiment. (author)
Particle physics experiments 1984
International Nuclear Information System (INIS)
Stuart, G.
1985-01-01
The Rutherford Appleton laboratory report describes work carried out in 1984 on experiments approved by the Particle Physics selection panel. The contents consist of unedited contributions from each experiment. (author)
AUTHOR|(CDS)2079874
2013-01-01
Unique in its coverage of all aspects of modern particle physics, this textbook provides a clear connection between the theory and recent experimental results, including the discovery of the Higgs boson at CERN. It provides a comprehensive and self-contained description of the Standard Model of particle physics suitable for upper-level undergraduate students and graduate students studying experimental particle physics. Physical theory is introduced in a straightforward manner with full mathematical derivations throughout. Fully-worked examples enable students to link the mathematical theory to results from modern particle physics experiments. End-of-chapter exercises, graded by difficulty, provide students with a deeper understanding of the subject. Online resources available at www.cambridge.org/MPP feature password-protected fully-worked solutions to problems for instructors, numerical solutions and hints to the problems for students and PowerPoint slides and JPEGs of figures from the book
Solovev, V
The SHiP Experiment is a new general-purpose fixed target facility at the SPS to search for hidden particles as predicted by a very large number of recently elaborated models of Hidden Sectors which are capable of accommodating dark matter, neutrino oscillations, and the origin of the full baryon asymmetry in the Universe. Specifically, the experiment is aimed at searching for very weakly interacting long lived particles including Heavy Neutral Leptons - right-handed partners of the active neutrinos; light supersymmetric particles - sgoldstinos, etc.; scalar, axion and vector portals to the hidden sector. The high intensity of the SPS and in particular the large production of charm mesons with the 400 GeV beam allow accessing a wide variety of light long-lived exotic particles of such models and of SUSY. Moreover, the facility is ideally suited to study the interactions of tau neutrinos.
2007-01-01
"Dateline video journalist Aaron Lewis this week reprots on the search to find the elusive "God particle", which, if found, could explain to scientists how everything in the world got its mass."(1/2 page)
International Nuclear Information System (INIS)
Mansouri, F.; Suranyi, P; Wijewardhana, L.C.R.
1991-10-01
In the test particle approximation, the scattering amplitude for two-particle scattering in (2+1)-dimensional Chern-Simons-Witten gravity and supergravity was computed and compared to the corresponding metric solutions. The formalism was then extended to the exact gauge theoretic treatment of the two-particle scattering problem and compared to 't Hooft's results from the metric approach. We have studied dynamical symmetry breaking in 2+1 dimensional field theories. We have analyzed strong Extended Technicolor (ETC) models where the ETC coupling is close to a critical value. There are effective scalar fields in each of the theories. We have worked our how such scalar particles can be produced and how they decay. The φ 4 field theory was investigated in the Schrodinger representation. The critical behavior was extracted in an arbitrary number of dimensions in second order of a systematic truncation approximation. The correlation exponent agrees with known values within a few percent
Particle Engulfment and Pushing
2001-01-01
As a liquefied metal solidifies, particles dispersed in the liquid are either pushed ahead of or engulfed by the moving solidification front. Similar effects can be seen when the ground freezes and pushes large particles out of the soil. The Particle Engulfment and Pushing (PEP) experiment, conducted aboard the fourth U.S. Microgravity Payload (USMP-4) mission in 1997, used a glass and plastic beads suspended in a transparent liquid. The liquid was then frozen, trapping or pushing the particles as the solidifying front moved. This simulated the formation of advanced alloys and composite materials. Such studies help scientists to understand how to improve the processes for making advanced materials on Earth. The principal investigator is Dr. Doru Stefanescu of the University of Alabama. This image is from a video downlink.
Big Bang Day: 5 Particles - 5. The Next Particle
Franck Close
2008-01-01
Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 5. The Next Particle The "sparticle" - a super symmetric partner to all the known particles could be the answer to uniting all the known particles and their interactions under one grand theoretical pattern of activity. But how do researchers know where to look for such phenomena and how do they know if they find them? Simon Singh reviews the next particle that physicists would like to find if the current particle theories are to ring true.
Safe biodegradable fluorescent particles
Martin, Sue I [Berkeley, CA; Fergenson, David P [Alamo, CA; Srivastava, Abneesh [Santa Clara, CA; Bogan, Michael J [Dublin, CA; Riot, Vincent J [Oakland, CA; Frank, Matthias [Oakland, CA
2010-08-24
A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.
PARTICLE BEAMS: Frontier course
International Nuclear Information System (INIS)
Anon.
1987-01-01
Driven by the quest for higher energies and optimal physics conditions, the behaviour of particle beams in accelerators and storage rings is the subject of increasing attention. Thus the second course organized jointly by the US and CERN Accelerator Schools looked towards the frontiers of particle beam knowledge. The programme held at South Padre Island, Texas, from 23-29 October attracted 125 participants including some 35 from Europe
Particle physics and cosmology
International Nuclear Information System (INIS)
Turner, M.S.; Schramm, D.N.
1985-01-01
During the past year, the research of the members of our group has spanned virtually all the topics at the interface of cosmology and particle physics: inflationary Universe scenarios, astrophysical and cosmological constraints on particle properties, ultra-high energy cosmic ray physics, quantum field theory in curved space-time, cosmology with extra dimensions, superstring cosmology, neutrino astronomy with large, underground detectors, and the formation of structure in the Universe
International Nuclear Information System (INIS)
Ried, L.
1982-01-01
A new device is claimed for detecting particles in a gas. The invention comprises a low cost, easy to assemble, and highly accurate particle detector using a single ionization chamber to contain a reference region and a sensing region. The chamber is designed with the radioactive source near one electrode and the second electrode located at a distance less than the distance of maximum ionization from the radioactive source
PARTICLE BEAMS: Frontier course
Energy Technology Data Exchange (ETDEWEB)
Anon.
1987-01-15
Driven by the quest for higher energies and optimal physics conditions, the behaviour of particle beams in accelerators and storage rings is the subject of increasing attention. Thus the second course organized jointly by the US and CERN Accelerator Schools looked towards the frontiers of particle beam knowledge. The programme held at South Padre Island, Texas, from 23-29 October attracted 125 participants including some 35 from Europe.
Hartsock, Robert
2011-10-01
The Least Particle Theory states that the universe was cast as a great sea of energy. MaX Planck declared a quantum of energy to be the least value in the universe. We declare the quantum of energy to be the least particle in the universe. Stephen Hawking declared quantum mechanics to be of no value in todays gross mechanics. That's like saying the number 1 has no place in mathematics.
International Nuclear Information System (INIS)
Siemens, P.J.; Jensen, A.S.
1985-01-01
It is shown that the opening of the 3-quasiparticle continuum at 3Δ sets the energy scale for the enhancement of the effective mass near the Fermi surface of nuclei. The authors argue that the spreading width of single-particle states due to coupling with low-lying collective modes is qualitatively different from the two-body collision mechanism, and contributes little to the single-particle lifetime in the sense of the optical model. (orig.)
Particle physics experiments 1986
International Nuclear Information System (INIS)
Stuart, G.W.
1987-01-01
The paper presents research work carried out in 1986 on 52 elementary particle experiments approved by the Particle Physics Experiments Selection Panel. Most of the experiments were collaborative and involved research groups from different countries. About half of the experiments were conducted at CERN, the remaining experiments employed the accelerators: LAMPT, LEP, PETRA, SLAC, and HERA. The contents consist of unedited contributions from each experiment. (U.K.)
Gravity, particles and astrophysics
International Nuclear Information System (INIS)
Wesson, P.S.
1980-01-01
The author deals with the relationship between gravitation and elementary particle physics, and the implications of these subjects for astrophysics. The text is split up into two parts. The first part represents a relatively non-technical overview of the subject, while the second part represents a technical examination of the most important aspects of non-Einsteinian gravitational theory and its relation to astrophysics. Relevant references from the fields of gravitation, elementary particle theory and astrophysics are included. (Auth.)
Particle electric dipole moments
Pendlebury, J M
2000-01-01
Measurements of particle electric dipole moments (EDMs) continue to put powerful constraints on theories of T-symmetry and CP-symmetry violation, which form currently one of the most prominent fields in particle physics. EDM measurements have been concentrated on neutral systems such as the neutron and atoms and molecules. These measurements allow one to deduce, in turn, the electric dipole moments of the fundamental fermions, that is, the lighter leptons and quarks and also those of some heavy nuclei.
Applications of particle accelerators
International Nuclear Information System (INIS)
Barbalat, O.
1994-01-01
Particle accelerators are now widely used in a variety of applications for scientific research, applied physics, medicine, industrial processing, while possible utilisation in power engineering is envisaged. Earlier presentations of this subject, given at previous CERN Accelerator School sessions have been updated with papers contributed to the first European Conference on Accelerators in Applied Research and Technology (ECAART) held in September 1989 in Frankfurt and to the Second European Particle Accelerator Conference in Nice in June 1990. (orig.)
Reddy, Ramana; Kumar, Sanjeev
2007-12-01
In this paper, we show through simulations that when sticky particles are broken continually, particles are dispersed into fine dust only if they are present in a narrow range of volume fractions. The upper limit of this range is 0.20 in the 2D and 0.10 in the 3D space. An increase in the dimensionality of space reduces the upper limit nearly by a factor of two. This scaling holds for dispersal of particles in hyperdimensional space of dimensions up to ten, the maximum dimension studied in this work. The maximum values of volume fractions obtained are significantly lower than those required for close packing and random packing of discs in 2D and spheres in 3D space. These values are also smaller than those required for critical phenomena of cluster percolation. The results obtained are attributed to merger cascades of sticky particles, triggered by breakup events. A simple theory that incorporates this cascade is developed to quantitatively explain the observed scaling of the upper limit with the dimensionality of space. The theory also captures the dynamics of the dispersal process in the corresponding range of particle volume fractions. The theory suggests that cascades of order one and two predominantly decide the upper limit for complete dispersal of particles.
International Nuclear Information System (INIS)
Gamboa, J.; Rivelles, V.O.
1989-01-01
Self-dual particles in two-dimensions are presented. They were obtained from chiral boson particle by square root technique. The propagator of spinning self-dual particle is calculated using the BFV formalism. (M.C.K.)
Suit, Herman
2013-11-01
The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter. Copyright © 2013 Elsevier Inc. All
Energy Technology Data Exchange (ETDEWEB)
Suit, Herman
2013-11-01
The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10{sup 80}. Protons were created at 10{sup −6} –1 second after the Big Bang at ≈1.37 × 10{sup 10} years beforethe present. Proton life span has been experimentally determined to be ≥10{sup 34} years; that is, the age of the universe is 10{sup −24}th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W{sup +}, W{sup −}, Z{sup 0}, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.
Entanglement between particle partitions in itinerant many-particle states
Haque, M.; Zozulya, O.S.; Schoutens, K.
2009-01-01
We review 'particle-partitioning entanglement' for itinerant many-particle systems. This is defined as the entanglement between two subsets of particles making up the system. We identify generic features and mechanisms of particle entanglement that are valid over whole classes of itinerant quantum
Particle physics and cosmology
International Nuclear Information System (INIS)
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
Neutron particle injection device
International Nuclear Information System (INIS)
Hashimoto, Kiyoshi.
1997-01-01
Plasma particles are used as target particles for converting ions to neutral particles by a charge exchange reaction in a neutralization cell, and a neutralization cell is disposed in adjacent with drawing electrodes. In addition, a magnetic field generation means is disposed additionally for generating magnetic rays substantially in parallel with the drawing electrode at the downmost stream in the progressing direction of the ions. The intensity of electric fields between the drawing electrode at the downmost stream and the nearest electrode, among electrodes present at the upstream, is made smaller than the intensity of electric fields between other electrodes. Since magnetic rays substantially in parallel with the drawing electrode at the downmost stream in the progressing direction of the ions are generated, the ions are prevented from being accelerated in the direction reverse to the progressing direction thereby further enhancing the neutralization efficiency of the neutralizing cell. Then, there can be provided effects that the constitution of the electrode of NBI (Neutral particle Beam Injector) can be simplified and the power source for preventing acceleration of neutral particles can be saved. (N.H.)
Cosmology and particle physics
International Nuclear Information System (INIS)
Salati, P.
1986-01-01
If the hot Big Bang model is correct, the very early universe provides us with a good laboratory to test our ideas on particle physics. The temperature and the density at that time are so high that each known particle must exist in chemical and in thermal equilibrium with the others. When the universe cools, the particles freeze out, leaving us today with a cosmic background. Such a kind of relic is of great interest because we can probe the Big Bang Model by studying the fossilized gas of a known particle. Conversely we can use that model to derive information about a hypothetical particle. Basically the freezing of a gas occurs a temperature T o and may be thermal or chemical. Studying the decoupling of a stable neutrino brings information on its mass: if the mass M ν lies in the forbidden range, the neutrino has to be unstable and its lifetime is constrained by cosmology. As for the G.U.T. Monopole, cosmology tells us that its present mass density is either to big or to small (1 monopole/observable universe) owing to a predicted flux far from the Parker Limit. Finally, the super red-giant star life time constrains the axion or the Higgs to be more massive than .2 MeV [fr
International Nuclear Information System (INIS)
Derrick, M.
1985-01-01
The Standard Model is a remarkable result of decades of work in particle physics, but it is clearly an incomplete representation of the world. Exploring possibilities beyond the Standard Model is a major preoccupation of both theorists and experimentalists. Despite the many suggestions that are extant about the missing links within the Standard Model as well as extensions beyond it, no hard experimental evidence exists. In particular, in more than five years of experimentation both at PETRA and PEP no new particles have been found that would indicate new physics. Several reasons are possible for these negative results: the particles may be too heavy; the experiments may not be looking in the proper way; the cross sections may be too small or finally the particles may not exist. A continuing PEP program, at high luminosity will ensure that the second and third reason continue to be addressed. The higher energy e + e - storage rings such as TRISTAN and LEP will extend the mass limits. High mass particles can also be produced at the CERN collider and soon with the Tevatron collider. A concise summary of the mass limits from the PETRA experiments has been given in a recent Mark J publication. The results shown provide a convenient yardstick against which to measure future search experiments
Big Bang Day: 5 Particles - 3. The Anti-particle
Franck Close
2008-01-01
Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.
Galdi, Giovanni; Nečasová, Šárka
2017-01-01
This book aims to face particles in flows from many different, but essentially interconnected sides and points of view. Thus the selection of authors and topics represented in the chapters, ranges from deep mathematical analysis of the associated models, through the techniques of their numerical solution, towards real applications and physical implications. The scope and structure of the book as well as the selection of authors was motivated by the very successful summer course and workshop "Particles in Flows'' that was held in Prague in the August of 2014. This meeting revealed the need for a book dealing with this specific and challenging multidisciplinary subject, i.e. particles in industrial, environmental and biomedical flows and the combination of fluid mechanics, solid body mechanics with various aspects of specific applications.
International Nuclear Information System (INIS)
Ress, T.I.; Nolde, G.V.
1974-01-01
A charged particle accelerator is described. It is made of an enclosure arranged for channeling a stream of charged particles along a predetermined path, and propelling means juxtaposed to said enclosure for generating therein a magnetic field moving in a predetermined direction with respect to each point of said path, the magnetic flux vector of that field being transverse to that path at every point, which gives the particles, along said path, a velocity connected to that of the mobile field by a predetermined relation. This can be applied to the fast production of chemical compounds, to the emission of neutrons and of thermal energy, and to the production of mechanical energy for propelling space ships [fr
Detectors for Particle Radiation
Kleinknecht, Konrad
1999-01-01
This textbook provides a clear, concise and comprehensive review of the physical principles behind the devices used to detect charged particles and gamma rays, and the construction and performance of these many different types of detectors. Detectors for high-energy particles and radiation are used in many areas of science, especially particle physics and nuclear physics experiments, nuclear medicine, cosmic ray measurements, space sciences and geological exploration. This second edition includes all the latest developments in detector technology, including several new chapters covering micro-strip gas chambers, silicion strip detectors and CCDs, scintillating fibers, shower detectors using noble liquid gases, and compensating calorimeters for hadronic showers. This well-illustrated textbook contains examples from the many areas in science in which these detectors are used. It provides both a coursebook for students in physics, and a useful introduction for researchers in other fields.
Energy Technology Data Exchange (ETDEWEB)
Ress, T I; Nolde, G V
1974-11-25
A charged particle accelerator is described. It is made of an enclosure arranged for channeling a stream of charged particles along a predetermined path, and propelling means juxtaposed to the enclosure for generating a magnetic field moving in a predetermined direction with respect to each point of the path, the magnetic flux vector of that field being transverse to that path at every point, which gives the particles, along said path, a velocity connected to that of the mobile field by a predetermined relation. This can be applied to the fast production of chemical compounds, to the emission of neutrons and of thermal energy, and to the production of mechanical energy for propelling space ships.
International Nuclear Information System (INIS)
Papiez, L.; Battista, J.J.
1994-01-01
The International Commission on Radiological Units and Measurements (ICRU) has defined fluence in terms of the number of the radiation particles crossing a small sampling sphere. A second definition has been proposed in which the length of track segments contained within any sampling volume are used to calculate the incident fluence. This approach is often used in Monte Carlo simulations of individual particle tracks, allowing the fluence to be scored in small volumes of any shape. In this paper we stress that the second definition generalizes the classical (ICRU) concept of fluence. We also identify the assumptions inherent in the two definitions of fluence and prove their equivalence for the case of straight-line particle trajectories. (author)
2002-01-01
The 2002 edition of the Review of Particle Physics has been published. It appears in the July 1st edition of Physical Review D with the reference: K. Hagiwara et al., Physical Review D66, 010001 (2002). The printing of the Particle Physics Booklets is planned to be finished at the end of August, so copies are expected to arrive at CERN for distribution by mid-September. The full data are available at the Berkeley site, as well as at various other mirrors around the world. As for copies of the full Review, for which CERN is responsible for the distribution outside the Americas, the Far East and Australasia, the quantity has been reduced by 60% compared to the 2000 edition. It will thus no longer be possible for all individuals to have their personal copy. Priority will be given to ensure that copies are sent to all groups and institutes engaged in particle physics research.
Wiedemann, Helmut
2015-01-01
This book by Helmut Wiedemann is a well-established, classic text, providing an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. The present 4th edition has been significantly revised, updated and expanded. The newly conceived Part I is an elementary introduction to the subject matter for undergraduate students. Part II gathers the basic tools in preparation of a more advanced treatment, summarizing the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part III is an extensive primer in beam dynamics, followed, in Part IV, by an introduction and description of the main beam parameters and including a new chapter on beam emittance and lattice design. Part V is devoted to the treatment of perturbations in beam dynamics. Part VI then discusses the details of charged particle acceleration. Parts VII and VIII introduce the more advanced topics of coupled beam dynamics and describe very intense bea...
AUTHOR|(CDS)2079223
2016-01-01
What is everything really made of? If we split matter down into smaller and infinitesimally smaller pieces, where do we arrive? At the Particle Zoo - the extraordinary subatomic world of antimatter, neutrinos, strange-flavoured quarks and yetis, gravitons, ghosts and glueballs, mindboggling eleven-dimensional strings and the elusive Higgs boson itself. Be guided around this strangest of zoos by Gavin Hesketh, experimental particle physicist at humanity's greatest experiment, the Large Hadron Collider. Concisely and with a rare clarity, he demystifies how we are uncovering the inner workings of the universe and heading towards the next scientific revolution. Why are atoms so small? How did the Higgs boson save the universe? And is there a theory of everything? The Particle Zoo answers these and many other profound questions, and explains the big ideas of Quantum Physics, String Theory, The Big Bang and Dark Matter...and, ultimately, what we know about the true, fundamental nature of reality.
Precision wood particle feedstocks
Dooley, James H; Lanning, David N
2013-07-30
Wood particles having fibers aligned in a grain, wherein: the wood particles are characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L; the L.times.H dimensions define two side surfaces characterized by substantially intact longitudinally arrayed fibers; the W.times.H dimensions define two cross-grain end surfaces characterized individually as aligned either normal to the grain or oblique to the grain; the L.times.W dimensions define two substantially parallel top and bottom surfaces; and, a majority of the W.times.H surfaces in the mixture of wood particles have end checking.
Sastri, Sankar
1990-01-01
The purpose of this experiment is to familiarize the student with magnetic particle inspection and relate it to classification of various defects. Magnetic particle inspection is a method of detecting the presence of cracks, laps, tears, inclusions, and similar discontinuities in ferromagnetic materials such as iron and steel. This method will most clearly show defects that are perpendicular to the magnetic field. The Magnaglo method uses a liquid which is sprayed on the workpiece to be inspected, and the part is magnetized at the same time. The workpiece is then viewed under a black light, and the presence of discontinuity is shown by the formation of a bright indication formed by the magnetic particles over the discontinuity. The equipment and experimental procedures are described.
International Nuclear Information System (INIS)
Horn, F.L.; Powell, J.R.; Savino, J.M.
1985-01-01
Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss
WORKSHOP: Stable particle motion
International Nuclear Information System (INIS)
Ruggiero, Alessandro G.
1993-01-01
Full text: Particle beam stability is crucial to any accelerator or collider, particularly big ones, such as Brookhaven's RHIC heavy ion collider and the larger SSC and LHC proton collider schemes. A workshop on the Stability of Particle Motion in Storage Rings held at Brookhaven in October dealt with the important issue of determining the short- and long-term stability of single particle motion in hadron storage rings and colliders, and explored new methods for ensuring it. In the quest for realistic environments, the imperfections of superconducting magnets and the effects of field modulation and noise were taken into account. The workshop was divided into three study groups: Short-Term Stability in storage rings, including chromatic and geometric effects and correction strategies; Long-Term Stability, including modulation and random noise effects and slow varying effects; and Methods for determining the stability of particle motion. The first two were run in parallel, but the third was attended by everyone. Each group considered analytical, computational and experimental methods, reviewing work done so far, comparing results and approaches and underlining outstanding issues. By resolving conflicts, it was possible to identify problems of common interest. The workshop reaffirmed the validity of methods proposed several years ago. Major breakthroughs have been in the rapid improvement of computer capacity and speed, in the development of more sophisticated mathematical packages, and in the introduction of more powerful analytic approaches. In a typical storage ring, a particle may be required to circulate for about a billion revolutions. While ten years ago it was only possible to predict accurately stability over about a thousand revolutions, it is now possible to predict over as many as one million turns. If this trend continues, in ten years it could become feasible to predict particle stability over the entire storage period. About ninety participants
International Nuclear Information System (INIS)
Dawson, J.M.
1988-01-01
The Superconducting Supercollider (SSC) will require an 87-kilometer accelerator ring to boost particles to 40 TeV. The SSC's size is due in part to the fact that its operating principle is the same one that has dominated accelerator design for 50 years: it guides particles by means of magnetic fields and propels them by strong electric fields. If one were to build an equally powerful but smaller accelerator, one would need to increase the strength of the guiding and propelling fields. Actually, however, conventional technology may not be able to provide significant increases in field strength. There are two reasons. First, the forces from magnetic fields are becoming greater than the structural forces that hold a magnetic material together; the magnets that produce these fields would themselves be torn apart. Second, the energy from electric fields is reaching the energies that bind electrons to atoms; it would tear electrons from nuclei in the accelerator's support structures. It is the electric field problem that plasma accelerators can overcome. Plasma particle accelerators are based on the principle that particles can be accelerated by the electric fields generated within a plasma. Because the plasma has already been ionized, plasma particle accelerators are not susceptible to electron dissociation. They can in theory sustain accelerating fields thousands of times stronger that conventional technologies. So far two methods for creating plasma waves for accelerators have been proposed and tested: the wakefield and the beat wave. Although promising electric fields have been produced, more research is necessary to determine whether plasma particle accelerators can compete with the existing accelerators. 7 figs
International Nuclear Information System (INIS)
Davies, G.E.; Janata, J.
1981-01-01
This patent claim on behalf of I.C.I. Ltd., relates to the preparation and use of composite magnetic particles, comprising a low density core, and having a magnetic coating over at least a proportion of the surface. The density of such particles can be chosen to suit a range of applications, e.g. in affinity chromatography, in radioimmunoassay, in the transport of the associated component, such as a drug or enzyme, to a specific site in a living organism. (U.K.)
International Nuclear Information System (INIS)
Salam, A.
1993-01-01
This article presents an overview of the situation in particle physics and a prognosis of its future: ideas which have been tested or will soon be tested (standard model and the light Higgs particle), ideas whose time has not yet come (supersymmetry, supersymmetry and N=1 supergravity, right-left symmetry and preons, unification of gravity with other forces, anomaly-free supergravities, supersymmetry strings, string theory as the ''Theory of Everything'' (T.O.E.); passive and non accelerator experiments. 6 figs., 2 tabs
International Nuclear Information System (INIS)
Frew, J.D.
1979-01-01
Apparatus and a method for collecting particles formed by vaporisation during a high temperature treatment of steel (eg cutting or welding) are described in which gas is drawn from the area in which the treatment is taking place through a collector in which the particles are separated magnetically. The air may be drawn by an air ejector from a hood around the treatment area. The invention has particular application where the high temperature treatment is the laser cutting of the stainless steel wrapper around a nuclear fuel sub-assembly. (author)
Energy Technology Data Exchange (ETDEWEB)
Sutton, Christine
1993-11-15
As well as being a leading physics writer, Christine Sutton of Oxford is also a particle physicist, currently working on the Zeus experiment at DESY's HERA electron-proton collider. Her latest book ''Spaceship Neutrino'' Cambridge University Press ISBN 0 521 36404 3 [hardback] or 0 521 36703 4 [paperback]) is a fascinating account of the emergence of the neutrino on the stage of science. In sixty years, the neutrino has been transformed from an apologetic idea its originator dared not publish to one of the main experimental tools of modern high energy research, while cosmologists have realized that this bizarre particle could play a major role in the Universe.
Beta particle measurement fundamentals
International Nuclear Information System (INIS)
Alvarez, J.L.
1986-01-01
The necessary concepts for understanding beta particle behavior are stopping power, range, and scattering. Dose as a consequence of beta particle interaction with tissue can be derived and explained by these concepts. Any calculations of dose, however, assume or require detailed knowledge of the beta spectrum at the tissue depth of calculation. A rudimentary knowledge of the incident spectrum can be of use in estimating dose, interpretating dose measuring devices and designing protection. The stopping power and range based on the csda will give a conservative estimate in cases of protection design, as scattering will reduce the range. Estimates of dose may be low because scattering effects were neglected
International Nuclear Information System (INIS)
Peierls, R.
1981-01-01
The particles and forces of matter, found in the Universe, are discussed with especial reference to some of the laws which govern behaviour in the sub-atomic world and which determine the way forces work to give matter its various characteristics. The recent history of the search for elementary constituents of matter in this century is outlined and the replacement of the simplicity anticipated in the 1930s by the proliferation of particle states uncovered in the 1950s and 1960s which led to the quark model is examined. (U.K.)
Single particle detecting telescope system
International Nuclear Information System (INIS)
Yamamoto, I.; Tomiyama, T.; Iga, Y.; Komatsubara, T.; Kanada, M.; Yamashita, Y.; Wada, T.; Furukawa, S.
1981-01-01
We constructed the single particle detecting telescope system for detecting a fractionally charged particle. The telescope consists of position detecting counters, wall-less multi-cell chambers, single detecting circuits and microcomputer system as data I/0 processor. Especially, a frequency of double particle is compared the case of the single particle detecting with the case of an ordinary measurement
Amorphous silicon ionizing particle detectors
Street, Robert A.; Mendez, Victor P.; Kaplan, Selig N.
1988-01-01
Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation.
New particle searches and discoveries
International Nuclear Information System (INIS)
Trippe, T.G.; Barbaro-Galtieri, A.; Horne, C.P.; Kelly, R.L.; Rittenberg, A.; Rosenfeld, A.H.; Yost, G.P.; Armstrong, B.; Bricman, C.; Hemingway, R.J.; Losty, M.J.; Roos, M.
1977-01-01
This supplement to the 1976 edition of 'Review of particle properties', Particle Data Group [Rev. Mod. Phys. 48, No. 2, Part II (1976)], contains tabulations of experimental data bearing on the 'new particles' and related topics; categories covered include charmed particles, psi's and their decay products, and heavy leptons. Errata to the previous edition are also given. (Auth.)
Matter: the fundamental particles
Landua, Rolf
2007-01-01
"The largest particle physics centre in the world is located in Europe. It straddles the Franco-Swiss border, near Geneva. At CERN - the European Organisation for Nuclear Research , which is focused on the science of nuclear matter rather than on the exploitation of atomic energy - there are over 6 500 scientists." (1 page)
Indian Academy of Sciences (India)
and “why is the universe the way it is?” Not long before ... to each other. The interactions of particles in the universe ... theory by Jean Perrin in 1908 convinced people that atoms and ..... ing the origin and evolution of our universe13. This is an ...
Elementary particle interactions
International Nuclear Information System (INIS)
Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Ward, B.F.L.; Close, F.E.; Christophorou, L.G.
1990-10-01
This report discusses freon bubble chamber experiments exposed to μ + and neutrinos, photon-proton interactions; shower counter simulations; SLD detectors at the Stanford Linear Collider, and the detectors at the Superconducting Super Collider; elementary particle interactions; physical properties of dielectric materials used in High Energy Physics detectors; and Nuclear Physics
Particle physics and cosmology
International Nuclear Information System (INIS)
Ellis, J.; Nanopoulos, D.
1983-01-01
The authors describe the connection between cosmology and particle physics in an introductory way. In this connection the big bang theory and unified gauge models of strong, electromagnetic, and weak interactions are considered. Furthermore cosmological nucleosynthesis is discussed in this framework, and the problem of cosmic neutrinos is considered with special regards to its rest mass. (HSI).
Humphries, Stanley
2013-01-01
Detailed enough for a text and sufficiently comprehensive for a reference, this volume addresses topics vital to understanding high-power accelerators and high-brightness-charged particle beams. Subjects include stochastic cooling, high-brightness injectors, and the free electron laser. Humphries provides students with the critical skills necessary for the problem-solving insights unique to collective physics problems. 1990 edition.
Loll, Anna-Cathrin
2009-01-01
"Rolf-Dieter Heuer is the new director general of the world's largest particle physics research center. Though the German physicist never expected to gain this influential position in Switzerland, it seems a natural step in his career trajectory" (1.5 pages)
Particle physics experiments 1982
International Nuclear Information System (INIS)
Rousseau, M.D.; Stuart, G.
1983-01-01
Work carried out in 1982 on 52 experiments approved by the Particle Physics Experiments Selection Panel is described. Each experiment is listed under title, collaboration, technique, accelerator, year of running, status and spokesman. Unedited contributions are given from each experiment. (U.K.)
International Nuclear Information System (INIS)
Biswas, M.
1975-01-01
In this review, some of the important aspects of energetic solar particles and their relation to solar physics are discussed. The major aspects of solar cosmic ray studies currently under investigation are identified and attention is focussed on the problems of the physical processes in the sun which may be responsible for these phenomena. The studies of the composition and energy spectra of solar cosmic ray nuclei are related to the basic problem of particle acceleration process in sun and to the composition of elements in solar atmosphere. The composition of higher energy (>20 MeV/amu) multiply charged nuclei of He, C, N, O, Ne, Mg, Si and Fe give information on the abundance of elements in the solar atmosphere. At lower energies (approximately 1-10 MeV/amu), the abundances of these elements show enhancements relative to solar abundances and these enhancements are believed to be due to particle acceleration mechanisms operative in the sun which are not fully understood at present. Studies of the relative abundances of H 2 , H 3 and He 3 isotopes and Li, Be, B nuclei in the solar cosmic rays can also be studied. The question of the relationship of the accelerated particles in the sun to the optical flare phenomena is discussed. Further studies of different aspects of these phenomena may give important clues to a wide ranging phenomena in the active sun. The observational methods employed for these studies are mentioned. (A.K.)
Jørgensen, Morten Dam
A search for hadronising long-lived massive particles at the Large Hadron Collider is conducted with the ATLAS detector. No excess events are found. Based on statistical analysis, upper limits on the production cross section are observed to be between $0.01$ pb and $0.006$ pb for colour octet particles (gluinos) with masses ranging from $300 \\ \\mathrm{GeV/c}^2$ to $1400 \\ \\mathrm{GeV/c}^2$, and $0.01$ pb to $0.004$ pb for colour triplet particles (stops and sbottoms) with masses ranging from $200 \\ \\mathrm{GeV/c}^2$ to $900 \\ \\mathrm{GeV/c}^2$. In the context of Supersymmetry with decoupled sfermion and sboson sectors (Split-SUSY), this gives a lower limit on the gluino mass of $989 \\ \\mathrm{GeV/c}^2$, and $683 \\ \\mathrm{GeV/c}^2$ for the stop mass and $618 \\ \\mathrm{GeV/c}^2$ for the sbottom mass. In addition, a new method is presented that improves the speed ($\\beta$) estimation for long-lived particles in the ATLAS tile calorimeter with a factor of $7$ improvement in resolution at low-$\\beta$ and ...
Particle physics experiments 1988
International Nuclear Information System (INIS)
Bairstow, R.
1989-01-01
This report describes work carried out in 1988 on experiments approved by the Particle Physics Experiments Selection Panel. The contents consist of unedited contributions from each experiment. More than forty projects at different accelerators (SPS, ISIS, PETRA, LAMPF, LEP, HERA, BNL, ILL, LEAR) are listed. Different organisations collaborate on different projects. A brief progress report is given. References to published articles are given. (author)
DEFF Research Database (Denmark)
Hansen, Linda Vadgård; Thorarinsdottir, Thordis Linda; Gneiting, Tilmann
to a von Mises–Fisher density, or uniform on a spherical cap, the correlation function of the associated random field admits a closed form expression. Using a Gaussian basis, the fractal or Hausdorff dimension of the surface of the Lévy particle reflects the decay of the correlation function at the origin...
Antonella Del Rosso
2012-01-01
In beautiful agreement with the Standard Model, two new excited states (see below) of the Λb beauty particle have just been observed by the LHCb Collaboration. Similarly to protons and neutrons, Λb is composed of three quarks. In the Λb’s case, these are up, down and… beauty. Although discovering new particles is increasingly looking like a routine exercise for the LHC experiments (see previous features), it is far from being an obvious performance, particularly when the mass of the particles is high. Created in the high-energy proton-proton collisions produced by the LHC, these new excited states of the Λb particle have been found to have a mass of, respectively, 5912 MeV/c2 and 5920 MeV/c2. In other words, they are over five times heavier than the proton or the neutron. Physicists only declare a discovery when data significantly show the relevant signal. In order to do that, they often have to analyse large samples of data. To ...
International Nuclear Information System (INIS)
Meyer-Berkhout, U.
1986-01-01
Remarkable progress has been achieved in the last two decades in the field of particle physics. From the insight gained by the many experimental data, physicists derive a framework picture of matter on the sub-nuclear level, consisting of fundamental components which interact with each other in a defined and quantitatively detectable manner. The data now available allowed a quantum field theory of strong interactions to be set up for the first time, and a unified theory of electromagnetic and weak interaction. Particle physicists today take particular interest in the problem of whether the strong interaction might fit into an extended unified theory. Such a grand unified theory would have a far-reaching impact on the conceptual models both of the cosmic and sub-nuclear dimensions, and possibly lead to observable effects in domains of energy and mass which will be opened up for experiments by the new accelerator generation underway. Current activities throughout the world for constructing or projecting the new high-energy particle accelerators are outlined in the article, together with the prospects expected by particle physicists, and a look back on the history and achievements of this field of science. (orig.) [de
Particle physics experiments 1992
International Nuclear Information System (INIS)
Roberts, B.A.
1993-03-01
The research programs described here were carried out in 1992 at Rutherford Appleton Laboratory and funded by the United Kingdom Science and Engineering Research Council. The area covered in these experiments is particle physics. Unedited contributions from over forty experimental programs are included. Experiments are listed according to their current status, the accelerator used and its years of operation. (UK)
International Nuclear Information System (INIS)
Hollabaugh, C.M.; Wagner, P.; Wahman, L.A.; White, R.W.
1977-01-01
Development of coating on nuclear fuel particles for the High-Temperature Fuels Technology program at the Los Alamos Scientific Laboratory included process studies for low-density porous and high-density isotropic carbon coats, and for ZrC and ''alloy'' C/ZrC coats. This report documents the data generated by these studies
International Nuclear Information System (INIS)
1990-01-01
It is discussed the physics in Brazil in the next decade with regard to elementary particles and field theories. The situation of brazilian research institutes as well as its personnel is also presented. Some recommendations and financing of new projects are also considered. (A.C.A.S.)
Elementary particle physics: Experimental
International Nuclear Information System (INIS)
Lord, J.J.; Burnett, T.H.; Wilkes, R.J.
1989-01-01
We are carrying out a research program in high energy experimental particle physics. Studies of high energy hadronic interactions and leptoproduction processes continue using several experimental techniques. Progress has been made on the study of multiparticle production processes in nuclei. Ultra-high energy cosmic ray nucleus-nucleus interactions have been investigated by the Japanese American Cosmic Emulsion Experiment (JACEE) using balloon-borne emulsion chamber detectors. In the area of particle astrophysics, our studies of cosmic ray nuclear interactions have enabled use to make the world's most accurate determination of the comparison of the cosmic rays above 10 13 eV. We have only the detector that can observe interaction vertices and identify particles at energies up to 10**15 eV. Our observations are getting close to placing limits on the acceleration mechanisms postulated for pulsars in which the spin and magnetic moment axes are at different angles. In June, 1989 approval was given by NASA for our participation in the Space Station program. The SCINATT experiment will make use of emulsion chamber detectors, similar to the planned JACEE hybrid balloon flight detectors. These detector will permit precise determination of secondary particle charges, momenta and rapidities, and the accumulation of data will be at least a factor of 10 to 100 greater than in balloon experiments. Emulsion chamber techniques ate also employed in an experiment using accelerator heavy ion beams at CERN and Brookhaven National Laboratory to investigate particle production processes in central collisions of nuclei in the energy range 15 -- 200A GeV. Our study of hadroproduction in lepton interactions is continuing with approval of another 8 months run for deep inelastic muon scattering experiment E665 at Fermilab
Particle Swarm Optimization Toolbox
Grant, Michael J.
2010-01-01
The Particle Swarm Optimization Toolbox is a library of evolutionary optimization tools developed in the MATLAB environment. The algorithms contained in the library include a genetic algorithm (GA), a single-objective particle swarm optimizer (SOPSO), and a multi-objective particle swarm optimizer (MOPSO). Development focused on both the SOPSO and MOPSO. A GA was included mainly for comparison purposes, and the particle swarm optimizers appeared to perform better for a wide variety of optimization problems. All algorithms are capable of performing unconstrained and constrained optimization. The particle swarm optimizers are capable of performing single and multi-objective optimization. The SOPSO and MOPSO algorithms are based on swarming theory and bird-flocking patterns to search the trade space for the optimal solution or optimal trade in competing objectives. The MOPSO generates Pareto fronts for objectives that are in competition. A GA, based on Darwin evolutionary theory, is also included in the library. The GA consists of individuals that form a population in the design space. The population mates to form offspring at new locations in the design space. These offspring contain traits from both of the parents. The algorithm is based on this combination of traits from parents to hopefully provide an improved solution than either of the original parents. As the algorithm progresses, individuals that hold these optimal traits will emerge as the optimal solutions. Due to the generic design of all optimization algorithms, each algorithm interfaces with a user-supplied objective function. This function serves as a "black-box" to the optimizers in which the only purpose of this function is to evaluate solutions provided by the optimizers. Hence, the user-supplied function can be numerical simulations, analytical functions, etc., since the specific detail of this function is of no concern to the optimizer. These algorithms were originally developed to support entry
Particle physics in your pocket!
Anaïs Schaeffer
2012-01-01
CERN physicists, take out your smartphones! Two new particle physics applications for Android phones have been developed by a physicist from the University of Bern: “Particle Properties” and “Particle Physics Booklet 2010”. “When I'm on shift, I enjoy looking at the online event displays,” says Igor Kreslo from the Laboratory for High Energy Physics at the University of Bern, the physicist who has developed the two particle physics applications for Android. “Sometimes very beautiful events appear, with many different particles. I like to discuss these displays with my students, just to develop their ability to identify particles. We try to find out which particle is which and how it might decay… I think that's the best way to teach students the phenomenology of particle physics.” When scientists study particle physics, they require some vital information, such as the decay branching ...
Energy Technology Data Exchange (ETDEWEB)
Rosenfeld, Carl [Univ of South Carolina; Mishra, Sanjib R. [Univ of South Carolina; Petti, Roberto [Univ of South Carolina; Purohit, Milind V. [Univ of South Carolina
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 Ba
Fundamentals of gas particle flow
Rudinger, G
1980-01-01
Fundamentals of Gas-Particle Flow is an edited, updated, and expanded version of a number of lectures presented on the "Gas-Solid Suspensions course organized by the von Karman Institute for Fluid Dynamics. Materials presented in this book are mostly analytical in nature, but some experimental techniques are included. The book focuses on relaxation processes, including the viscous drag of single particles, drag in gas-particles flow, gas-particle heat transfer, equilibrium, and frozen flow. It also discusses the dynamics of single particles, such as particles in an arbitrary flow, in a r
Particle measurement systems and methods
Steele, Paul T [Livermore, CA
2011-10-04
A system according to one embodiment includes a light source for generating light fringes; a sampling mechanism for directing a particle through the light fringes; and at least one light detector for detecting light scattered by the particle as the particle passes through the light fringes. A method according to one embodiment includes generating light fringes using a light source; directing a particle through the light fringes; and detecting light scattered by the particle as the particle passes through the light fringes using at least one light detector.
Effective particle magnetic moment of multi-core particles
International Nuclear Information System (INIS)
Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; IJzendoorn, Leo J. van; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer
2015-01-01
In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm
Effective particle magnetic moment of multi-core particles
Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; van IJzendoorn, Leo J.; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer
2015-04-01
In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems - BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm - and one single-core particle system - SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.
Effective particle magnetic moment of multi-core particles
Energy Technology Data Exchange (ETDEWEB)
Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden); Wetterskog, Erik; Svedlindh, Peter [Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lak, Aidin; Ludwig, Frank [Institute of Electrical Measurement and Fundamental Electrical Engineering, TU Braunschweig, D‐38106 Braunschweig Germany (Germany); IJzendoorn, Leo J. van [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Westphal, Fritz; Grüttner, Cordula [Micromod Partikeltechnologie GmbH, D ‐18119 Rostock (Germany); Gehrke, Nicole [nanoPET Pharma GmbH, D ‐10115 Berlin Germany (Germany); Gustafsson, Stefan; Olsson, Eva [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Johansson, Christer, E-mail: christer.johansson@acreo.se [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden)
2015-04-15
In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.
International Nuclear Information System (INIS)
Rosner, J.L.
1979-01-01
Conventional estimates are reviewed for charmed particle lifetimes. Free-quark models give values of (a few) x 10 -13 sec to (a few) x 10 -12 sec. The shorter of these values also follows from an extrapolation based on D → Ke/sup nu/. Possible differences among the lifetimes and production rates of D 0 , D + , F + , C 0 + , the heavy lepton tau, and the fifth quark b are discussed. Extreme values of mixing angles in a six-quark model could extend charmed particle lifetimes by a factor of at most three from the above estimates, while shorter lifetimes than those predicted could occur for some species like D 0 or F + if their nonleptonic decays were enhanced. The predictions are discussed in the light of some current experimental results, and it is estimated that sigma(pp → charm) approx. = 10 μb at 400 GeV/c. 95 references
International Nuclear Information System (INIS)
1993-08-01
This proposal presents the research accomplishments and ongoing activities of Boston University researchers in high energy physics. Some changes have been made in the structure of the program from the previous arrangement of tasks. Task B, Accelerator Design Physics, is being submitted as a separate proposal for an independent grant; this will be consistent with the nature of the research and the source of funding. We are active in seven principal areas which will be discussed in this report: Colliding Beams - physics of e + e - and bar pp collisions; MACRO Experiment - search for magnetic monopoles and study of cosmic rays; Proton Decay - search for nucleon instability and study of neutrino interactions; Particle Theory - theoretical high energy particle physics, including two Outstanding Junior Investigator awards; Muon G-2 - measurement of the anomalous magnetic moment of the muon; SSCintcal - calorimetry for the GEM Experiment; and Muon detectors for the GEM Experiment
International Nuclear Information System (INIS)
Zink, S.
1987-01-01
The Radiation Research Program (RRP) supports a variety of research through grants and contracts. During the last few years, considerable effort has been devoted to treatment planning evaluation in particle, photon and electron radiotherapy. In 1981, RRP issued a request for proposals (RFP) for the evaluation of treatment planning with particle beam radiotherapy - to include protons, heavy ions and neutrons. Contracts were subsequently awarded to four institutions: Massachusetts General Hospital (MGH), University of Texas and M.D. Anderson Hospital (MDAH), the heavy ion project at Lawrence Berkeley Laboratory (LBL) and University of Pennsylvania (UPa). These contracts reached completion December 31, 1986. The work for the contracts was carried out at the individual institutions and guided through a Working Group made up of the Project Officer and Principal Investigators and primary physicians and physicists at each of the participating institutions. This report summarizes the findings of the Working Group and makes recommendations for further research
Ultralight particle dark matter
International Nuclear Information System (INIS)
Ringwald, A.
2013-10-01
We review the physics case for very weakly coupled ultralight particles beyond the Standard Model, in particular for axions and axion-like particles (ALPs): (i) the axionic solution of the strong CP problem and its embedding in well motivated extensions of the Standard Model; (ii) the possibility that the cold dark matter in the Universe is comprised of axions and ALPs; (iii) the ALP explanation of the anomalous transparency of the Universe for TeV photons; and (iv) the axion or ALP explanation of the anomalous energy loss of white dwarfs. Moreover, we present an overview of ongoing and near-future laboratory experiments searching for axions and ALPs: haloscopes, helioscopes, and light-shining-through-a-wall experiments.
Bernstein, Jeremy
2013-01-01
From molecules to stars, much of the cosmic canvas can be painted in brushstrokes of primary color: the protons, neutrons, and electrons we know so well. But for meticulous detail, we have to dip into exotic hues - leptons, mesons, hadrons, quarks. Bringing particle physics to life as few authors can, Jeremy Bernstein here unveils nature in all its subatomic splendor. In this graceful account, Bernstein guides us through high-energy physics from the early twentieth century to the present, including such highlights as the newly discovered Higgs boson. Beginning with Ernest Rutherford's 1911 explanation of the nucleus, a model of atomic structure emerged that sufficed until the 1930s, when new particles began to be theorized and experimentally confirmed. In the postwar period, the subatomic world exploded in a blaze of unexpected findings leading to the theory of the quark, in all its strange and charmed variations. An eyewitness to developments at Harvard University and the Institute for Advanced Study in Prin...
SYMPOSIUM: Particle identification
Energy Technology Data Exchange (ETDEWEB)
Anon.
1989-07-15
Typical elementary particle experiments consist of a source of interactions (an external beam and a fixed target or two colliding beams) and a detector system including most of the following components: a tracking system and analysis magnet, calorimetry (measurement of energy deposition), hadron and electron identification, muon detection, trigger counters and processors, and data acquisition electronics. Experiments aimed at future high luminosity hadron collider (proton-proton or proton-antiproton) projects such as an upgraded Tevatron at Fermilab, the Large Hadron Collider (LHC) idea at CERN, and the proposed US Superconducting Supercollider (SSC), must ideally cover the entire solid angle and be capable of not only surviving the collisions, but also providing high resolution event information at incredible interaction rates. The Symposium on Particle Identification at High Luminosity Hadron Colliders held at Fermilab from 5-7 April (sponsored by Fermilab, the US Department of Energy, and the SSC Central Design Group) focused on this single facet of detector technology.
Ultralight particle dark matter
Energy Technology Data Exchange (ETDEWEB)
Ringwald, A.
2013-10-15
We review the physics case for very weakly coupled ultralight particles beyond the Standard Model, in particular for axions and axion-like particles (ALPs): (i) the axionic solution of the strong CP problem and its embedding in well motivated extensions of the Standard Model; (ii) the possibility that the cold dark matter in the Universe is comprised of axions and ALPs; (iii) the ALP explanation of the anomalous transparency of the Universe for TeV photons; and (iv) the axion or ALP explanation of the anomalous energy loss of white dwarfs. Moreover, we present an overview of ongoing and near-future laboratory experiments searching for axions and ALPs: haloscopes, helioscopes, and light-shining-through-a-wall experiments.
International Nuclear Information System (INIS)
2000-01-01
The present collection of letters from JINR, Dubna, contains seven separate records on the integral representation for structure functions and target mass effects, multiscale properties of DNA primary structure including cross-scale correlations, dissipative evolution of the elementary act, the fine structure of the M T =1 Gamow-Teller resonance in 147g Tb→ 147 Gd β + /EC decay, the behaviour of the TVO temperature sensors in the magnetic fields, a fast method for searching for tracks in multilayer drift chambers of HADES spectrometer, a novel approach to particle track etching including surfactant enhanced control of pore morphology, azimuthal correlations of secondary particles in 32 S induced interactions with Ag(Br) nuclei at 4.5 GeV/ c/ nucleon
Particle detector spatial resolution
International Nuclear Information System (INIS)
Perez-Mendez, V.
1992-01-01
Method and apparatus for producing separated columns of scintillation layer material, for use in detection of X-rays and high energy charged particles with improved spatial resolution is disclosed. A pattern of ridges or projections is formed on one surface of a substrate layer or in a thin polyimide layer, and the scintillation layer is grown at controlled temperature and growth rate on the ridge-containing material. The scintillation material preferentially forms cylinders or columns, separated by gaps conforming to the pattern of ridges, and these columns direct most of the light produced in the scintillation layer along individual columns for subsequent detection in a photodiode layer. The gaps may be filled with a light-absorbing material to further enhance the spatial resolution of the particle detector. 12 figs
International Nuclear Information System (INIS)
Sutton, Christine
1993-01-01
As well as being a leading physics writer, Christine Sutton of Oxford is also a particle physicist, currently working on the Zeus experiment at DESY's HERA electron-proton collider. Her latest book ''Spaceship Neutrino'' Cambridge University Press ISBN 0 521 36404 3 [hardback] or 0 521 36703 4 [paperback]) is a fascinating account of the emergence of the neutrino on the stage of science. In sixty years, the neutrino has been transformed from an apologetic idea its originator dared not publish to one of the main experimental tools of modern high energy research, while cosmologists have realized that this bizarre particle could play a major role in the Universe
Supersymmetric particles at LEP
International Nuclear Information System (INIS)
Barbiellini, G.; Coignet, G.; Gaillard, M.K.; Bonneaud, G.; Ellis, J.; Matteuzzi, C.; Wiik, H.
1979-10-01
The authors examine whether the supersymmetrization of nature at a mass scale up to 100 GeV can be confirmed or excluded by experiments with LEP. They review the qualitative features of the spectroscopy suggested by supersymmetric theories. Then they discuss possible production rates and means of detection of these particles at LEP. In this framework they make some remarks about other projects for future high energy physics machines which can be used for the study of supersymmetric phenomena. (HSI)
Relaxation from particle production
Energy Technology Data Exchange (ETDEWEB)
Hook, Anson; Marques-Tavares, Gustavo [Stanford Institute for Theoretical Physics, Stanford University, Stanford, CA 94305 (United States)
2016-12-20
We consider using particle production as a friction force by which to implement a “Relaxion” solution to the electroweak hierarchy problem. Using this approach, we are able to avoid superplanckian field excursions and avoid any conflict with the strong CP problem. The relaxation mechanism can work before, during or after inflation allowing for inflationary dynamics to play an important role or to be completely decoupled.
Making elementary particles visible
Energy Technology Data Exchange (ETDEWEB)
Cohen, Eyal [ArSciMed (art, science, media), 100, rue du Faubourg Saint Antoine, 75012 Paris (France)
1994-07-15
Ever since the days of the ancient Greek atomists, the notion that matter is made up of tiny fundamental elements has dominated the history of scientific theories. Elementary particles (and now strings...) are the latest in this chronological list of fundamental objects. Our notions of what a physical theory should be like, and what precisely ''matter is made up of...'' really means, have evolved with the years, undergoing a profound revolution with quantum mechanics.
Forecasting report. Particle physics
International Nuclear Information System (INIS)
The present status of particle and antiparticle physics is examined. As for electromagnetic interactions, the quantum electrodynamics theory is briefly reviewed and the various types of hadronic electromagnetic interactions classified. The theoretical approaches of strong interactions are outlined with hadron spectroscopy. Dynamical models and high energy phenomena are presented. The theoretical problems of weak interaction physics are examined with some experimental aspects. Experimental investigations of the hadron internal structure are briefly surveyed [fr
Making elementary particles visible
International Nuclear Information System (INIS)
Cohen, Eyal
1994-01-01
Ever since the days of the ancient Greek atomists, the notion that matter is made up of tiny fundamental elements has dominated the history of scientific theories. Elementary particles (and now strings...) are the latest in this chronological list of fundamental objects. Our notions of what a physical theory should be like, and what precisely ''matter is made up of...'' really means, have evolved with the years, undergoing a profound revolution with quantum mechanics
An active particle accelerator
International Nuclear Information System (INIS)
Goldman, T.
1991-01-01
Although a static charge is difficult to maintain on macroscopic particles, it is straightforward to construct a small object with a regularly oscillating electric dipole moment. For objects of a given size, one may then construct an accelerator by appropriately matching the frequency and separations of an external array of electrodes to this size. Physically feasible size ranges, an accelerator design, and possible applications of such systems are discussed. 8 refs., 9 figs
Introduction to elementary particles
Griffiths, David J
2008-01-01
This is the first quantitative treatment of elementary particle theory that is accessible to undergraduates. Using a lively, informal writing style, the author strikes a balance between quantitative rigor and intuitive understanding. The first chapter provides a detailed historical introduction to the subject. Subsequent chapters offer a consistent and modern presentation, covering the quark model, Feynman diagrams, quantum electrodynamics, and gauge theories. A clear introduction to the Feynman rules, using a simple model, helps readers learn the calculational techniques without the complicat
International Nuclear Information System (INIS)
Turner, N.L.
1982-01-01
A particle beam accelerator is described which has several electrodes that are selectively short circuited together synchronously with changes in the magnitude of a DC voltage applied to the accelerator. By this method a substantially constant voltage gradient is maintained along the length of the unshortened electrodes despite variations in the energy applied to the beam by the accelerator. The invention has particular application to accelerating ion beams that are implanted into semiconductor wafers. (U.K.)
Multiscale Simulations Using Particles
DEFF Research Database (Denmark)
Walther, Jens Honore
vortex methods for problems in continuum fluid dynamics, dissipative particle dynamics for flow at the meso scale, and atomistic molecular dynamics simulations of nanofluidic systems. We employ multiscale techniques to breach the atomistic and continuum scales to study fundamental problems in fluid...... dynamics. Recent work on the thermophoretic motion of water nanodroplets confined inside carbon nanotubes, and multiscale techniques for polar liquids will be discussed in detail at the symposium....
Radiation in Particle Simulations
International Nuclear Information System (INIS)
More, R.; Graziani, F.; Glosli, J.; Surh, M.
2010-01-01
Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of megabars to thousands of gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present four methods that attempt a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The first method applies the Lienard-Weichert solution of Maxwell's equations for a classical particle whose motion is assumed to be known. The second method expands the electromagnetic field in normal modes (planewaves in a box with periodic boundary-conditions) and solves the equation for wave amplitudes coupled to the particle motion. The third method is a hybrid molecular dynamics/Monte Carlo (MD/MC) method which calculates radiation emitted or absorbed by electron-ion pairs during close collisions. The fourth method is a generalization of the third method to include small clusters of particles emitting radiation during close encounters: one electron simultaneously hitting two ions, two electrons simultaneously hitting one ion, etc. This approach is inspired by the virial expansion method of equilibrium statistical mechanics. Using a combination of these methods we believe it is possible to do atomic-scale particle simulations of
'Hot particle' intercomparison dosimetry
International Nuclear Information System (INIS)
Kaurin, D.G.L.; Baum, J.W.; Charles, M.W.; Darley, D.P.J.; Durham, J.S.; Scannell, M.J.; Soares, C.G.
1996-01-01
Dosimetry measurements of four 'hot particles' were made at different density thickness values using five different methods. The hot particles had maximum dimensions of 650 μm and maximum beta energies of 0.97, 046, 0.36, and 0.32 MeV. Absorbers were used to obtain the dose at different depths for each dosimeter. Measurements were made using exoelectron dosimeters, an extrapolation chamber, NE Extremity Tape Dosimeters (tm), Eberline RO-2 and RO-2A survey meters, and two sets of GafChromic (tm) dye film with each set read out at a different institution. From these results the dose was calculated averaged over 1 cm 2 of tissue at 18, 70, 125, and 400 μm depth. Comparisons of tissue-dose averaged over 1 cm 2 for 18, 70, and 125 μm depth based on interpolated measured values, were within 30% for the GafChromic (tm) dye film, extrapolation chamber, NE Extremity Tape Dosimeters (tm), and Eberline RO-2 and 2A (tm) survey meters except for the hot particle with 0.46 MeV maximum beta energy. The results for this source showed differences of up to 60%. The extrapolation chamber and NE Extremity Tape dosimeters under-responded for measurements at 400 μm by about a factor of 2 compared with the GafChromic dye films for two hot particles with maximum beta energy of 0.32 and 0.36 MeV which each emitted two 100% 1 MeV photons per disintegration. Tissue doses determined using exoelectron dosimeters were a factor of 2 to 5 less than those determined using other dosimeters, possibly due to failures of the equipment. (author)
Theory of particle interactions
International Nuclear Information System (INIS)
Belokurov, V.V.; Shirkov, D.V.
1986-01-01
Development and modern state of the theory of elementary particle interactions is described. The main aim of the paper is to give a picture of quantum field theory development in the form easily available for physicists not occupied in this field of science. Besides the outline of chronological development of main representations, the description of renormalization and renorm-groups, gauge theories, models of electro-weak interactions and quantum chromodynamics, the latest investigations related to joining all interactions and supersymmetries is given
International Nuclear Information System (INIS)
Zeldovich, Ya. B.
1984-01-01
A general review is given on the historical development and on the present status of main physical ideas and theories. The concepts of particles, fields and interactions are discussed in detail including most recent developments. The present basic theories of physics: general relativity, gauge theory of electroweak interaction and quantum chromodynamics, their new results and their possible unification are analyzed. The author emphasizes the importance of knowledge as an inherent need of mankind. (D.Gy)
Particles beams and applications
International Nuclear Information System (INIS)
Uzureau, J.L.
1996-01-01
This issue of the ''Chocs'' journal is devoted to particles beams used by the D.A.M. (Direction of Military Applications) and to their applications. The concerned beams are limited to those in an energy range from hundred of Kev to several Gev. Light ions (protons, deuterons, alpha) where it is easy to produce neutrons sources and heavy ions (from carbon to gold). (N.C.). 8 refs., 2 figs
International Nuclear Information System (INIS)
Powell, Andrew
2010-01-01
Particle identification (PID) is a fundamental requirement for LHCb and is provided by CALO, MUON and RICH sub-detectors. The Calorimeters provide identification of electrons, photons and hadrons in addition to the measurement of their energies and positions. As well as being part of the LHCb trigger, the MUON system provides identification of muons to a very high level of purity, essential for many CP-sensitive measurements that have J/ψ's in their final states. Hadron identification, in particular the ability to distinguish kaons and pions, is crucial to many LHCB analyses, particularly where the final states of interest are purely hadronic. The LHCb RICH system provides this, covering a momentum range between 1 and 100 GeV/c. To maintain the integrity of the LHCb physics performance, it is essential to measure and monitor the particle identification efficiency and mis-identification fraction over time. This can be done by using specific decays, such as K-shorts, φ's, Λ's, J/ψ's and D*'s, for which pure samples can be isolated using only kinematic quantities, due to their unique decay topologies. This allows for clean samples of known particle types to be selected, which can then be used to calibrate and monitor the PID performance from data. The procedures for performing this will be presented, together with preliminary results from the 2009 and 2010 LHC runs. (author)
International Nuclear Information System (INIS)
Van Dam, J.W.
1989-01-01
The title of this book, From Particles to Plasmas, has more than one meaning. First, it reflects how the scientific career of Marshall Rosenbluth has evolved, beginning in the field of elementary particle physics and extending into his major area of plasma physics. Secondly, it is meant to suggest the wide spectrum of subject matters addressed in the individual lectures, ranging from numerical simulation and space physics and accelerators to various subfields in the physics of plasmas. In the third place, the title is a reference to the way in which the theoretical description of plasmas is often constructed, namely starting from the motion of single particles and then incorporating collective effects. Most of the contributions in this book do concern various aspects of fusion plasma physics, which is the field in which most of Marshall Rosenbluth's scientific contributions have been and are being made. In this field his eminence and authority are indicated by the sobriquet pope of plasma physics that is often applied to him
CERN Bulletin
2010-01-01
Particles are supplied to the LHC by six accelerators inter-connected by several kilometres of transfer lines. This represents yet another complex chain of processes whereby particles are produced, bunched, synchronised and injected into the LHC at the precise moment it's ready to receive them. In other words, for collisions to be produced at the end of the chain, all the injectors must be in perfect working order. Among all the questions asked by the many visitors to CERN, one in particular comes up time and time again: "Why don't you just connect the LHC directly to the proton source?" In other words, why do you need this whole chain of accelerators acting as an "injector" for the LHC? Before colliding inside the LHC, particles first have to pass through no fewer than six different accelerators: the 90 keV duoplasmatron source, the 750 keV RFQ, the 50 MeV Linac 2, the 1.4 GeV synchrotron injector ("PS Booster" or PSB), the 25 GeV Proton Sy...
Rainbow Particle Imaging Velocimetry
Xiong, Jinhui
2017-04-27
Despite significant recent progress, dense, time-resolved imaging of complex, non-stationary 3D flow velocities remains an elusive goal. This work tackles this problem by extending an established 2D method, Particle Imaging Velocimetry, to three dimensions by encoding depth into color. The encoding is achieved by illuminating the flow volume with a continuum of light planes (a “rainbow”), such that each depth corresponds to a specific wavelength of light. A diffractive component in the camera optics ensures that all planes are in focus simultaneously. With this setup, a single color camera is sufficient to track 3D trajectories of particles by combining 2D spatial and 1D color information. For reconstruction, this thesis derives an image formation model for recovering stationary 3D particle positions. 3D velocity estimation is achieved with a variant of 3D optical flow that accounts for both physical constraints as well as the rainbow image formation model. The proposed method is evaluated by both simulations and an experimental prototype setup.
Superconductivity of small particles
International Nuclear Information System (INIS)
Leavens, C.R.; Fenton, E.W.
1981-01-01
The Eliashberg gap equations are used to investigate the contribution of surface-phonon softening to the size dependence of the superconducting transition temperature (T/sub c/) of small metallic particles. Because of our limited quantitative knowledge of phonon spectra and electron-phonon coupling in the surface region, the effect cannot be calculated with certainty. Previous calculations which agree with experiment depend on a fortuitous choice of input parameters which cannot be justified at present. For this reason the absence of any observable size effect for T/sub c/ in Pb is especially important. This null effect is obtained in Pb if the electron-phonon coupling strength is the same in the surface region as in the bulk. This assumption can be tested experimentally because it means that the energy gap of Pb should not be independent of particle size but rather should increase significantly with decreasing radius. Hence, measurement of the size dependence of the energy gap for well-characterized small particles of Pb could provide information regarding the importance of the phonon-softening mechanism, at least for Pb
Turbulence and particle acceleration
International Nuclear Information System (INIS)
Scott, J.S.
1975-01-01
A model for the production of high energy particles in the supernova remnant Cas A is considered. The ordered expansion of the fast moving knots produce turbulent cells in the ambient interstellar medium. The turbulent cells act as magnetic scattering centers and charged particles are accelerated to large energies by the second order Fermi mechanism. Model predictions are shown to be consistent with the observed shape and time dependence of the radio spectrum, and with the scale size of magnetic field irregularities. Assuming a galactic supernova rate at 1/50 yr -1 , this mechanism is capable of producing the observed galactic cosmic ray flux and spectrum below 10 16 eV/nucleon. Several observed features of galactic cosmic rays are shown to be consistent with model predictions. A model for the objects known as radio tall galaxies is also presented. Independent blobs of magnetized plasma emerging from an active radio galaxy into an intracluster medium become turbulent due to Rayleigh--Taylor and Kelvin--Helmholz instabilities. The turbulence produces both in situ betatron and 2nd order Fermi accelerations. Predictions of the dependence of spectral index and flux on distance along the tail match observations well. Fitting provides values of physical parameters in the blobs. The relevance of this method of particle acceleration for the problem of the origin of x-ray emission in clusters of galaxies is discussed
Quantum principles and particles
Wilcox, Walter
2012-01-01
QUANTUM PRINCIPLESPerspective and PrinciplesPrelude to Quantum MechanicsStern-Gerlach Experiment Idealized Stern-Gerlach ResultsClassical Model AttemptsWave Functions for Two Physical-Outcome CaseProcess Diagrams, Operators, and Completeness Further Properties of Operators/ModulationOperator ReformulationOperator RotationBra-Ket Notation/Basis StatesTransition AmplitudesThree-Magnet Setup Example-CoherenceHermitian ConjugationUnitary OperatorsA Very Special OperatorMatrix RepresentationsMatrix Wave Function RecoveryExpectation ValuesWrap Up ProblemsFree Particles in One DimensionPhotoelectric EffectCompton EffectUncertainty Relation for PhotonsStability of Ground StatesBohr ModelFourier Transform and Uncertainty RelationsSchrödinger EquationSchrödinger Equation ExampleDirac Delta FunctionsWave Functions and ProbabilityProbability CurrentTime Separable SolutionsCompleteness for Particle StatesParticle Operator PropertiesOperator RulesTime Evolution and Expectation ValuesWrap-UpProblemsSome One-Dimensional So...
Duality and 'particle' democracy
Castellani, Elena
2017-08-01
Weak/strong duality is usually accompanied by what seems a puzzling ontological feature: the fact that under this kind of duality what is viewed as 'elementary' in one description gets mapped to what is viewed as 'composite' in the dual description. This paper investigates the meaning of this apparent 'particle democracy', as it has been called, by adopting an historical approach. The aim is to clarify the nature of the correspondence between 'dual particles' in the light of a historical analysis of the developments of the idea of weak/strong duality, starting with Dirac's electric-magnetic duality and its successive generalizations in the context of (Abelian and non-Abelian) field theory, to arrive at its first extension to string theory. This analysis is then used as evidential basis for discussing the 'elementary/composite' divide and, after taking another historical detour by analyzing an instructive analogy case (DHS duality and related nuclear democracy), drawing some conclusions on the particle-democracy issue.
New particles and interactions
International Nuclear Information System (INIS)
Gilman, F.J.; Grannis, P.D.
1984-04-01
The Working Group on New Particles and Interactions met as a whole at the beginning and at the end of the Workshop. However, much of what was accomplished was done in five subgroups. These were devoted to: (1) new quarks and leptons; (2) technicolor; (3) supersymmetry; (4) rare decays and CP; and (5) substructure of quarks and leptons. Other aspects of new particles, e.g., Higgs, W', Z', fell to the Electroweak Working Group to consider. The central question of this Workshop of comparing anti pp (with L = 10 32 /cm 2 -sec) with pp (with L = 10 33 /cm 2 -sec) colliders carried through to all these subgroups. In addition there were several other aspects of hadron colliders which were considered: what does an increase in √s gain in cross section and resultant sensitivity to new physics versus an increase in luminosity; will polarized beams or the use of asymmetries be essential in finding new interactions; where and at what level do rate limitations due to triggering or detection systems play a role; and how and where will the detection of particles with short, but detectable, lifetimes be important. 25 references
Particle production by neutrinos
International Nuclear Information System (INIS)
Schreiner, P.
1979-01-01
A review is given of particle production by neutrinos in charged-current inclusive and exclusive channels. The production rates for various particles in neutrino-nucleon interactions at a beam energy of 25 GeV are compared. The mesons are, of course, dominated by pion production. The p 0 (760) rate is an order of magnitude smaller. Strange and charm pseudoscalar mesons are a further factor of two down in rate. The strange vector mesons are suppressed by more than an order of magnitude relative to K 0 production; however, the charmed D* + (2010) is only a factor of two smaller in rate than the D 0 (1860). With regards to the baryons, most of them are, of course, nucleons. The Λ 0 and Y*(1385) rates are down by one and two orders of magnitudes, respectively. The lower limit on the charmed Σ/sub c/ ++ baryon rate is similar to the Y*(1385) rate. Finally, the quasielastic and one-pion production exclusive channels have about the same cross section as that of the D* + ; associated production of strange particles in the νn → μ - K + Λ channel and the ΔS = +ΔΩ process νp → μ - pK + are down by factors of five and twenty, respectively, compared to the quasielastic cross section
International Nuclear Information System (INIS)
Morris, Chris
2004-01-01
The Coulomb multiple scattering of charged particles as they pass through material allows them to be used as a radiographic probe. This forms the basis for a new kind of radiography that is finding application where conventional x-ray radiography is limited by flux or backgrounds. Charged-particle radiography is providing a versatile new probe that has advantages over conventional x-ray radiography for some unique application. Proton radiography has been used to make quantitative motion pictures of high explosive driven experiments and proves to be of great value for radiographing experiments that mock up nuclear weapon primaries for stockpile certification. By taking advantage of magnetic lens to magnify images and by using the very bright beams that can be made with electrons, charged-particle radiography may be useful for studying the fine spatial detail and very fast motion in laser driven implosion experiments at the National Ignition Facility. Finally, radiographs can be made using cosmic-ray muons for searching vehicles and cargo containers for surreptitious cargo of high z materials such as uranium or plutonium.
Cosmology with decaying particles
International Nuclear Information System (INIS)
Turner, M.S.
1984-09-01
We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons β -1 identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (β) family of solutions; physically β -1 approx. = (Ω/sub R//Ω/sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references
Cosmology with decaying particles
Energy Technology Data Exchange (ETDEWEB)
Turner, M.S.
1984-09-01
We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons ..beta../sup -1/ identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (..beta..) family of solutions; physically ..beta../sup -1/ approx. = (..cap omega../sub R//..cap omega../sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references.
Is an elementary particle really: (i) a particle? (ii) elementary?
Indian Academy of Sciences (India)
First page Back Continue Last page Overview Graphics. Is an elementary particle really: (i) a particle? (ii) elementary? Over centuries, naïve notions about this have turned out incorrect. Particles are not really pointlike. The word elementary is not necessarily well-defined. Notes:
Alumina particle degradation during solid particle impact on glass
Slikkerveer, P.J.; Veld, in 't H.; Verspui, M.A.; With, de G.; Reefman, D.
2000-01-01
Particle degradation limits the reuse of powders in industrial powder-blast processes. In this paper the degradation behavior of Al2O3 powder is studied during erosion of glass substrates. Three techniques were used on original and multiply used powders: particle size measurements, single particle
International Nuclear Information System (INIS)
Tkachev, Igor
1993-01-01
When the common ground between particle physics, astrophysics and cosmology started to become a developing area, the Institute for Nuclear Research (INR) of the Russian Academy of Sciences had the foresight in 1981 to institute the Baksan Schools on Particles and Cosmology. This now traditional event, held biannually in the Baksan Valley, has gone on to attract international participation. The site is close to the INR Baksan Neutrino Observatory with its underground and surface installations, including the SAGE gallium solar neutrino detector, the Underground Scintillation Telescope, and the 'Carpet' extensive air shower array. Participation is mainly from experimentalists working in non accelerator particle physics and particle astrophysics. The most recent School, held from April 21 to 28, began with an opening address by INR Director V. A. Matveev. J.Frieman reviewed standard big bang cosmology, emphasizing how the recent COBE results and the observations of large scale galaxy clustering fit into a standard cosmology framework. For inflationary cosmology, he showed how different models may be tested through their predictions for large-scale galactic structure and for cosmic microwave background anisotropy. A.Stebbins presented details of the large scale distribution of galaxies which, combined with velocity information and microwave background anisotropy data, provide strong constraints on theories of the origin of primordial inhomogeneities. Inflation requires, and theories of the large scale structure strongly favour the critical value for the cosmic mass density, while, as D.Seckel explained in his lecture on nucleosynthesis and abundances of the light elements, the baryon contribution to this density has to be tens of times smaller. A general review on the observational evidence for dark matter, dark matter particle candidates and the strategy of dark matter searches was given by I. Tkachev, who stressed the gravitational microlensing MACHO
Particle accelerator; the Universe machine
Yurkewicz, Katie
2008-01-01
"In summer 2008, scientists will switch on one of the largest machines in the world to search for the smallest of particle. CERN's Large Hadron Collider particle accelerator has the potential to chagne our understanding of the Universe."
Steering particles by breaking symmetries
Bet, Bram; Samin, Sela; Georgiev, Rumen; Burak Eral, Huseyin; van Roij, René
2018-06-01
We derive general equations of motions for highly-confined particles that perform quasi-two-dimensional motion in Hele-Shaw channels, which we solve analytically, aiming to derive design principles for self-steering particles. Based on symmetry properties of a particle, its equations of motion can be simplified, where we retrieve an earlier-known equation of motion for the orientation of dimer particles consisting of disks (Uspal et al 2013 Nat. Commun. 4), but now in full generality. Subsequently, these solutions are compared with particle trajectories that are obtained numerically. For mirror-symmetric particles, excellent agreement between the analytical and numerical solutions is found. For particles lacking mirror symmetry, the analytic solutions provide means to classify the motion based on particle geometry, while we find that taking the side-wall interactions into account is important to accurately describe the trajectories.
Particle acceleration by plasma waves
International Nuclear Information System (INIS)
Joshi, C.
2006-01-01
In an advanced particle accelerator particles are driven near by light velocity through ionized gas. Such plasma devices are compact, cost efficient and usable in many fields. Examples are given in detail. (GL)
Relating particles and texture perception
Engelen, L.; Wijk, de R.A.; Bilt, van der A.; Prinz, J.F.; Janssen, A.M.; Bosman, F.
2005-01-01
Practically all foods contain particles. It has been suggested that the presence of particles in food may affect the perception of sensory attributes. In the present study we investigated the effect of size and type (hardness and shape) of particles added to a CMC based vanilla custard dessert. The
Particle levitation and laboratory scattering
International Nuclear Information System (INIS)
Reid, Jonathan P.
2009-01-01
Measurements of light scattering from aerosol particles can provide a non-intrusive in situ method for characterising particle size distributions, composition, refractive index, phase and morphology. When coupled with techniques for isolating single particles, considerable information on the evolution of the properties of a single particle can be gained during changes in environmental conditions or chemical processing. Electrostatic, acoustic and optical techniques have been developed over many decades for capturing and levitating single particles. In this review, we will focus on studies of particles in the Mie size regime and consider the complimentarity of electrostatic and optical techniques for levitating particles and elastic and inelastic light scattering methods for characterising particles. In particular, we will review the specific advantages of establishing a single-beam gradient force optical trap (optical tweezers) for manipulating single particles or arrays of particles. Recent developments in characterising the nature of the optical trap, in applying elastic and inelastic light scattering measurements for characterising trapped particles, and in manipulating particles will be considered.
Particle acceleration by electromagnetic pulses
International Nuclear Information System (INIS)
Lai, H.M.
1982-01-01
Particle interaction with plane electromagnetic pulses is studied. It is shown that particle acceleration by a wavy pulse, depending on the shape of the pulse, may not be small. Further, a diffusive-type particle acceleration by multiple weak pulses is described and discussed. (author)
Quantum entanglement of identical particles
International Nuclear Information System (INIS)
Shi Yu
2003-01-01
We consider entanglement in a system with a fixed number of identical particles. Since any operation should be symmetrized over all the identical particles and there is the precondition that the spatial wave functions overlap, the meaning of identical-particle entanglement is fundamentally different from that of distinguishable particles. The identical-particle counterpart of the Schmidt basis is shown to be the single-particle basis in which the one-particle reduced density matrix is diagonal. But it does not play a special role in the issue of entanglement, which depends on the single-particle basis chosen. The nonfactorization due to (anti)symmetrization is naturally excluded by using the (anti)symmetrized basis or, equivalently, the particle number representation. The natural degrees of freedom in quantifying the identical-particle entanglement in a chosen single-particle basis are occupation numbers of different single-particle basis states. The entanglement between effectively distinguishable spins is shown to be a special case of the occupation-number entanglement
Random packing of digitized particles
Korte, de A.C.J.; Brouwers, H.J.H.
2013-01-01
The random packing of regularly and irregularly shaped particles has been studied extensively. Within this paper, packing is studied from the perspective of digitized particles. These digitized particles are developed for and used in cellular automata systems, which are employed for the simple
Single particle distributions, ch.2
International Nuclear Information System (INIS)
Blokzijl, R.
1977-01-01
A survey of inclusive single particle distributions is given for various particles. A comparison of particle cross-sections measured in K - p experiments at different center of mass energies shows that some of these cross-sections remain almost constant over a wide range of incoming K - momenta
Random packing of digitized particles
de Korte, A.C.J.; Brouwers, Jos
2012-01-01
The random packing of regularly and irregularly shaped particles has been studied extensively. Within this paper, packing is studied from the perspective of digitized particles. These digitized particles are developed for and used in cellular automata systems, which are employed for the simple
Particle-two particle interaction in configuration space
International Nuclear Information System (INIS)
Kuzmichev, V.E.
1982-07-01
The problem if three indentical particles with zero-range two-particle interaction is considered. An explicit expression for the effective potential between one particle and the remaining two-particle system is obtained in the coordinate representation. It is shown that for arbitrary energies, at small and, for zero energy, at large distances rho between the one particle and centre of mass of the other two particles the diagonal matrix element of the effective potential is attractive and proportional to 1/rho 2 . This property of the effective potenial explains both the Thomas singularity and the Efimov effect. In the case of zero total energy of the system the general form of the solution of the three-particle integral equation is found in configuration space. (orig.)
Particle size distribution control of Pt particles used for particle gun
Ichiji, M.; Akiba, H.; Nagao, H.; Hirasawa, I.
2017-07-01
The purpose of this study is particle size distribution (PSD) control of submicron sized Pt particles used for particle gun. In this report, simple reaction crystallization is conducted by mixing H2PtCl6 and ascorbic acid. Without the additive, obtained Pt particles have broad PSD and reproducibility of experiment is low. With seeding, Pt particles have narrow PSD and reproducibility improved. Additionally, mean particle diameter of 100-700 nm is controlled by changing seeding amount. Obtained particles are successfully characterized as Pt by XRD results. Moreover, XRD spectra indicate that obtained particles are polycrystals. These experimental results suggest that seeding consumed nucleation, as most nuclei attached on the seed surface. This mechanism virtually restricted nucleation to have narrow PSD can be obtained.
Particle acceleration in binaries
Directory of Open Access Journals (Sweden)
Sinitsyna V.G.
2017-01-01
Full Text Available Cygnus X-3 massive binary system is one of the powerful sources of radio and X-ray emission consisting of an accreting compact object, probably a black hole, with a Wolf-Rayet star companion. Based on the detections of ultra high energy gamma-rays by Kiel and Havera Park, Cygnus X-3 has been proposed to be one of the most powerful sources of charged cosmic ray particles in the Galaxy. The results of long-term observations of the Cyg X-3 binary at energies 800 GeV–85 TeV detected by SHALON in 1995 are presented with images, integral spectra and spectral energy distribution. The identification of source with Cygnus X-3 detected by SHALON was secured by the detection of its 4.8 hour orbital period in TeV gamma-rays. During the whole observation period of Cyg X-3 with SHALON significant flux increases were detected at energies above 0.8 TeV. These TeV flux increases are correlated with flaring activity at a lower energy range of X-ray and/or at observations of Fermi LAT as well as with radio emission from the relativistic jets of Cygnus X-3. The variability of very high-energy gamma-radiation and correlation of radiation activity in the wide energy range can provide essential information on particle mechanism production up to very high energies. Whereas, modulation of very high energy emission connected to the orbital motion of the binary system, provides an understanding of the emission processes, nature and location of particle acceleration.
International Nuclear Information System (INIS)
Alonso, J.R.
1995-05-01
Radiation therapy with ''hadrons'' (protons, neutrons, pions, ions) has accrued a 55-year track record, with by now over 30,000 patients having received treatments with one of these particles. Very good, and in some cases spectacular results are leading to growth in the field in specific well-defined directions. The most noted contributor to success has been the ability to better define and control the radiation field produced with these particles, to increase the dose delivered to the treatment volume while achieving a high degree of sparing of normal tissue. An additional benefit is the highly-ionizing, character of certain beams, leading to creater cell-killing potential for tumor lines that have historically been very resistant to radiation treatments. Until recently these treatments have been delivered in laboratories and research centers whose primary, or original mission was physics research. With maturity in the field has come both the desire to provide beam facilities more accessible to the clinical setting, of a hospital, as well as achieving, highly-efficient, reliable and economical accelerator and beam-delivery systems that can make maximum advantage of the physical characteristics of these particle beams. Considerable work in technology development is now leading, to the implementation of many of these ideas, and a new generation of clinically-oriented facilities is beginning to appear. We will discuss both the physical, clinical and technological considerations that are driving these designs, as well as highlighting, specific examples of new facilities that are either now treating, patients or that will be doing so in the near future
International Nuclear Information System (INIS)
Ning, H.; Chong-shi, W.
1986-01-01
This book contains the proceedings of the September symposium. There are two parts to this book divided according to particle physics and nuclear physics. Some of the titles of the papers are as follows: Bifurcation and Dynamical Symmetry Breaking, Negative Binomial Distribution for the Multiplicity Distributions in e/sup +/e/sup -/ Annihilation, Variational Study of Lattice QCD, Rescaling for Kaon Structure Function, SDG Boson Model and its Application, The Pair-Aligned Intrinsic Wave Function in Single-j Configuration, and The Short Range Effective Interaction and the Spectra of Calcium Isotopes in (f-p) Space
Online Particle Physics Information
International Nuclear Information System (INIS)
Kreitz, Patricia A
2003-01-01
This list describes a broad set of online resources that are of value to the particle physics community. It is prescreened and highly selective. It describes the scope, size, and organization of the resources so that efficient choices can be made amongst many sites which may appear similar. A resource is excluded if it provides information primarily of interest to only one institution. Because this list must be fixed in print, it is important to consult the updated version of this compilation which includes newly added resources and hypertext links to more complete information at: http://www.slac.stanford.edu/library/pdg/
Acceleration of polarized particles
International Nuclear Information System (INIS)
Buon, J.
1992-05-01
The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab
International Nuclear Information System (INIS)
2002-01-01
The present collection of letters from JINR, Dubna, contains eight separate records on the role of the complanar emission of particles in nuclear interaction for E 0 >10 16 eV detected in the stratosphere, 10 B nucleus fragment yields, nuclear teleportation (proposal for an experiment), invisible 'glue' bosons in model field theory, calculation of the ionization differential effective cross sections in fast ion-atom collisions, interactions of ultracold neutrons near surface of solids, g factors as a probe for high-spin structure of neutron-rich Dy isotopes, search for periodicities in experimental data by the autoregressive model methods
Quantum principles and particles
Wilcox, Walter
2018-01-01
This textbook offers a unique introduction to quantum mechanics progressing gradually from elementary quantum mechanics to aspects of particle physics. It presents the microscopic world by analysis of the simplest possible quantum mechanical system (spin 1/2). A special feature is the author’s use of visual aids known as process diagrams, which show how amplitudes for quantum mechanical processes are computed. The second edition include a new chapter on time-dependent processes, in addition to many new problems and improved illustrations.
Particle localization detector
International Nuclear Information System (INIS)
Allemand, R.
1976-01-01
A proportional detector for the localization of particles comprises a leak-tight chamber filled with fluid and fitted with an electrode of a first type consisting of one or more conducting wires and with an electrode of a second type consisting of one or more conducting plates having the shape of a portion of cylindrical surface and a contour which provides a one-to-one correspondence between the position of a point of the wires and the solid angle which subtends the plate at that point, means being provided for collecting the electrical signal which appears on the plates. 12 Claims, 10 Drawing Figures
Cosmology and particle physics
International Nuclear Information System (INIS)
Turner, M.S.
1985-01-01
The author reviews the standard cosmology, focusing on primordial nucleosynthesis, and discusses how the standard cosmology has been used to place constraints on the properties of various particles. Baryogenesis is examined in which the B, C, CP violating interactions in GUTs provide a dynamical explanation for the predominance of matter over antimatter and the present baryon-to-baryon ratio. Monoposes, cosmology and astrophysics are reviewed. The author also discusses supersymmetry/supergravity and cosmology, superstrings and cosmology in extra dimensions, and axions, astrophics, and cosmology
Linac particle tracing simulations
International Nuclear Information System (INIS)
Lysenko, W.P.
1979-01-01
A particle tracing code was developed to study space--charge effects in proton or heavy-ion linear accelerators. The purpose is to study space--charge phenomena as directly as possible without the complications of many accelerator details. Thus, the accelerator is represented simply by harmonic oscillator or impulse restoring forces. Variable parameters as well as mismatched phase--space distributions were studied. This study represents the initial search for those features of the accelerator or of the phase--space distribution that lead to emittance growth
Green, Dan
1994-01-01
The aim of this book on particle physics is to present the theory in a simple way. The style and organization of the material is unique in that intuition is employed, not formal theory or the Monte Carlo method. This volume attempts to be more physical and less abstract than other texts without degenerating into a presentation of data without interpretation.This book is based on four courses of lectures conducted at Fermilab. It should prove very useful to advanced undergraduates and graduate students.
Online Particle Physics Information
Energy Technology Data Exchange (ETDEWEB)
Kreitz, Patricia A
2003-04-24
This list describes a broad set of online resources that are of value to the particle physics community. It is prescreened and highly selective. It describes the scope, size, and organization of the resources so that efficient choices can be made amongst many sites which may appear similar. A resource is excluded if it provides information primarily of interest to only one institution. Because this list must be fixed in print, it is important to consult the updated version of this compilation which includes newly added resources and hypertext links to more complete information at: http://www.slac.stanford.edu/library/pdg/.
Localization of relativistic particles
International Nuclear Information System (INIS)
Omnes, R.
1997-01-01
In order to discuss localization experiments and also to extend the consistent history interpretation of quantum mechanics to relativistic properties, the techniques introduced in a previous paper [J. Math. Phys. 38, 697 (1997)] are applied to the localization of a photon in a given region of space. An essential requirement is to exclude arbitrarily large wavelengths. The method is valid for a particle with any mass and spin. Though there is no proper position operator for a photon, one never needs one in practice. Causality is valid up to exponentially small corrections. copyright 1997 American Institute of Physics
International Nuclear Information System (INIS)
Barnett, R.M.
1977-03-01
Direct and indirect evidence for the existence of a new heavy quark b and of new heavy neutral leptons N/sub e/ and N/sub μ/ can be sought in neutrino and e + e - scattering. These particles are expected to have right-handed currents. Discussion is given on the characteristics, production and decay of hadrons such as bb, ub and db, and of the massive neutral leptons. Muon number violation with and without N/sub e/ and N/sub μ/ is considered
Michell, S J
2013-01-01
Fluid and Particle Mechanics provides information pertinent to hydraulics or fluid mechanics. This book discusses the properties and behavior of liquids and gases in motion and at rest. Organized into nine chapters, this book begins with an overview of the science of fluid mechanics that is subdivided accordingly into two main branches, namely, fluid statics and fluid dynamics. This text then examines the flowmeter devices used for the measurement of flow of liquids and gases. Other chapters consider the principle of resistance in open channel flow, which is based on improper application of th
Sapyta, Joe; Reid, Hank; Walton, Lew
The topics are presented in viewgraph form and include the following: particle bed reactor (PBR) core cross section; PBR bleed cycle; fuel and moderator flow paths; PBR modeling requirements; characteristics of PBR and nuclear thermal propulsion (NTP) modeling; challenges for PBR and NTP modeling; thermal hydraulic computer codes; capabilities for PBR/reactor application; thermal/hydralic codes; limitations; physical correlations; comparison of predicted friction factor and experimental data; frit pressure drop testing; cold frit mask factor; decay heat flow rate; startup transient simulation; and philosophy of systems modeling.
1982-06-28
Superintendent NOTICE Reproduction of this document in any form by other than naval activities is/Jotbvlhorized except isys^iedcil approval of the SecretarWof...constant. •.■, -1 "if -w \\ SÄNPLlWi V» IVf Figure 3.1.1.1 Simplified Oil Path Ref 21 Scott. D, McCullagh. PJ and Campbell GW Condition Monitoring...Wear Particles in Human Synovial Fluid Arthritis and Rheumatism, 24 (1981) 912-918 30 Evans. C H .andTew W P isolationof Biological Materials
Dusty-Plasma Particle Accelerator
Foster, John E.
2005-01-01
A dusty-plasma apparatus is being investigated as means of accelerating nanometer- and micrometer-sized particles. Applications for the dusty-plasma particle accelerators fall into two classes: Simulation of a variety of rapidly moving dust particles and micrometeoroids in outer-space environments that include micrometeoroid streams, comet tails, planetary rings, and nebulae and Deposition or implantation of nanoparticles on substrates for diverse industrial purposes that could include hardening, increasing thermal insulation, altering optical properties, and/or increasing permittivities of substrate materials. Relative to prior apparatuses used for similar applications, dusty-plasma particle accelerators offer such potential advantages as smaller size, lower cost, less complexity, and increased particle flux densities. A dusty-plasma particle accelerator exploits the fact that an isolated particle immersed in plasma acquires a net electric charge that depends on the relative mobilities of electrons and ions. Typically, a particle that is immersed in a low-temperature, partially ionized gas, wherein the average kinetic energy of electrons exceeds that of ions, causes the particle to become negatively charged. The particle can then be accelerated by applying an appropriate electric field. A dusty-plasma particle accelerator (see figure) includes a plasma source such as a radio-frequency induction discharge apparatus containing (1) a shallow cup with a biasable electrode to hold the particles to be accelerated and (2) a holder for the substrate on which the particles are to impinge. Depending on the specific design, a pair of electrostatic-acceleration grids between the substrate and discharge plasma can be used to both collimate and further accelerate particles exiting the particle holder. Once exposed to the discharge plasma, the particles in the cup quickly acquire a negative charge. Application of a negative voltage pulse to the biasable electrode results in the
Apparatus for blending small particles
International Nuclear Information System (INIS)
Bradley, R.A.; Reese, C.R.; Sease, J.D.
1975-01-01
An apparatus is described for blending small particles and uniformly loading the blended particles in a receptacle. Measured volumes of various particles are simultaneously fed into a funnel to accomplish radial blending and then directed onto the apex of a conical splitter which collects the blended particles in a multiplicity of equal subvolumes. Thereafter the apparatus sequentially discharges the subvolumes for loading in a receptacle. A system for blending nuclear fuel particles and loading them into fuel rod molds is described in a preferred embodiment
Particle acceleration in modified shocks
International Nuclear Information System (INIS)
Drury, L.O'C.; Axford, W.I.; Summers, D.
1982-01-01
Efficient particle acceleration in shocks must modify the shock structure with consequent changes in the particle acceleration. This effect is studied and analytic solutions are found describing the diffusive acceleration of particles with momentum independent diffusion coefficients in hyperbolic tangent type velocity transitions. If the input particle spectrum is a delta function, the shock smoothing replaces the truncated power-law downstream particle spectrum by a more complicated form, but one which has a power-law tail at high momenta. For a cold plasma this solution can be made completely self-consistent. Some problems associated with momentum dependent diffusion coefficients are discussed. (author)
Particle acceleration in modified shocks
Energy Technology Data Exchange (ETDEWEB)
Drury, L.O' C. (Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany, F.R.)); Axford, W.I. (Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.)); Summers, D. (Memorial Univ. of Newfoundland, St. John' s (Canada))
1982-03-01
Efficient particle acceleration in shocks must modify the shock structure with consequent changes in the particle acceleration. This effect is studied and analytic solutions are found describing the diffusive acceleration of particles with momentum independent diffusion coefficients in hyperbolic tangent type velocity transitions. If the input particle spectrum is a delta function, the shock smoothing replaces the truncated power-law downstream particle spectrum by a more complicated form, but one which has a power-law tail at high momenta. For a cold plasma this solution can be made completely self-consistent. Some problems associated with momentum dependent diffusion coefficients are discussed.
Dark matter and particle physics
International Nuclear Information System (INIS)
Peskin, Michael E.
2007-01-01
Astrophysicists now know that 80% of the matter in the universe is 'dark matter', composed of neutral and weakly interacting elementary particles that are not part of the Standard Model of particle physics. I will summarize the evidence for dark matter. I will explain why I expect dark matter particles to be produced at the CERN LHC. We will then need to characterize the new weakly interacting particles and demonstrate that they the same particles that are found in the cosmos. I will describe how this might be done. (author)
Orbital Picture of Yu-Shiba-Rusinov Multiplets
Heinrich, Benjamin W.; Ruby, Michael; Franke, Katharina J.; Peng, Yang; von Oppen, Felix
Magnetic impurities on an s-wave superconductor induce Yu-Shiba-Rusinov (YSR) bound states within the excitation gap of the superconductor. Here, we investigate single manganese (Mn) atoms adsorbed on different surface orientations of superconducting lead (Pb) and the nature of their YSR states. Depending on the adsorption site and surface, we detect a distinct number and characteristic patterns of YSR states around the Mn atoms. We show that the YSR states inherit their properties from the Mn d levels, which are split by the surrounding crystal field. The periodicity of the long-range YSR oscillations allows us to identify a dominant coupling of the d states to the outer Fermi sheet of the two-band superconductor Pb. The long-range and directional nature of the states are promising for the design of coupled adatom structures, which could bear topological phases. We acknowledge funding by the Deutsche Forschungsgemeinschaft through Grant No. FR2726/4 and through collaborative research Grants No. Sfb 658, No. CRC 183, and No. SPP 1666, as well as by the European Research Council through Consolidator Grant NanoSpin.
N=1 superfield anatomy of the Fayet-Sohnius multiplet
International Nuclear Information System (INIS)
Galperin, A.; Ivanov, E.; Ogievetsky, V.
1981-01-01
The constraints on N=2 Fayet-Sohnius superfield are interpreted as analyticity conditions. This N=2 superfield reduces to two chiral N=1 superfields defined in two different complex (4.2) superspaces, both on and off mass shell. The central charge operator is realized bilinearly in spinor derivatives [ru
Massive and massless supersymmetry: Multiplet structure and unitary irreducible representations
International Nuclear Information System (INIS)
Jarvis, P.D.
1976-01-01
UIR's of the supersymmetry algebra for the massive and massless cases are analyzed covariantly (without the use of induced representations) in terms of their component spins. For the massive case normalized basis vectors vertical-barp 2 >0, j 0 ; sigma; pjlambda> are constructed, where j 0 is the ''superspin'' and sigma is an additional quantum number serving to distinguish the different vertical-barpjlambda>, the constituent p 2 >0, spin-j UIR's of the Poincare group. For the massless case, normalized basis vectors vertical-barp 2 =0, lambda 0 ; plambda> are similarly constructed, where lambda 0 is the ''superhelicity.'' Matrix elements of the supersymmetry generators, in these bases, are explicitly given. The ''sigma basis'' is used to define weight diagrams for the massive UIR's of supersymmetry, and their properties are briefly described. Eigenfunctions ω/sub sigma/(theta) are also defined, and their connection with the reduction of higher spin massive superfields PHI/subJ/(x,theta) is discussed. Finally, it is shown how gauge dependence necessarily arises with certain massless superfields. The massless scalar superfield, both gauge-dependent and gauge-independent, is discussed as an example
Racah materials: role of atomic multiplets in intermediate valence systems
Czech Academy of Sciences Publication Activity Database
Shick, Alexander; Havela, L.; Lichtenstein, A.I.; Katsnelson, M.I.
2015-01-01
Roč. 5, Oct (2015), s. 15429 ISSN 2045-2322 R&D Projects: GA ČR GA15-07172S Institutional support: RVO:68378271 Keywords : SmB 6 * localization * magnetism Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 5.228, year: 2015
Recommendations, requirements, and radioactive particles
International Nuclear Information System (INIS)
Bell, J.M.
1991-01-01
Hot particles consisting of activated metal debris and fuel fragments have received increased attention in the last five years. This increased attention resulted from the increased use of more sensitive whole body friskers at nuclear power plants, the relatively high local skin doses associated with the particles, and skin dose limits that were established before hot particles, and skin dose limits that were established before hot particles became a problem and before radiobiological effects data for the particles became available. The skin dose distribution and biological effects associated with hot particles differ from those associated with more uniform skin contamination and differences exist in the scientific community as to which effects should be protected against by a limit on exposures from particles. The NRC staff recognized the need for provisions in the Federal regulations specific to hot particle exposures and requested guidance from the National Council on Radiation Protection and Measurements (NCRP). NCRP Report No. 106 was provided to the NRC early in 1990. The International Commission on Radiological Protection (ICRP) is also developing recommendations for limits on exposures from hot particles. The NRC is supporting research on hot particle effects and will likely develop a rule for hot particle exposures
Particle therapy for noncancer diseases
Energy Technology Data Exchange (ETDEWEB)
Bert, Christoph; Engenhart-Cabillic, Rita; Durante, Marco [GSI Helmholtzzentrum fuer Schwerionenforschung, Biophysics Department, Planckstrasse 1, 64291 Darmstadt (Germany); Philipps-University Marburg, Center for Radiology, Department of Radiation Therapy, Baldinger Strasse, 35043 Marburg (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Biophysics Department, Planckstrasse 1, 64291 Darmstadt (Germany); Technische Universitaet Darmstadt, Institut fuer Festkoerperphysik, Hochschulstrasse 3, 64289 Darmstadt (Germany) and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany)
2012-04-15
Radiation therapy using high-energy charged particles is generally acknowledged as a powerful new technique in cancer treatment. However, particle therapy in oncology is still controversial, specifically because it is unclear whether the putative clinical advantages justify the high additional costs. However, particle therapy can find important applications in the management of noncancer diseases, especially in radiosurgery. Extension to other diseases and targets (both cranial and extracranial) may widen the applications of the technique and decrease the cost/benefit ratio of the accelerator facilities. Future challenges in this field include the use of different particles and energies, motion management in particle body radiotherapy and extension to new targets currently treated by catheter ablation (atrial fibrillation and renal denervation) or stereotactic radiation therapy (trigeminal neuralgia, epilepsy, and macular degeneration). Particle body radiosurgery could be a future key application of accelerator-based particle therapy facilities in 10 years from today.
Method of stripping solid particles
International Nuclear Information System (INIS)
1980-01-01
A method of stripping loaded solid particles is specified in which uniform batches of the loaded particles are passed successively upwardly through an elution column in the form of discrete plugs, the particles of which do not intermingle substantially with the particles of the vertically adjacent plug(s), and are contacted therein with eluant liquid flowed downwardly, strong eluate being withdrawn from the lower region of the column, the loaded particles being supplied as a slurry in a carrier liquid, and successive batches of loaded particles being isolated as measured batches and being separated from their carrier liquid before being contacted with strong eluate and slurried with the strong eluate into the lower region of the column. An example describes the stripping of ion exchange resin particles loaded with complex uranium ions. (author)
Chicago particle accelerator conference
International Nuclear Information System (INIS)
Southworth, Brian
1989-01-01
Naturally, emphasis at the Particle Accelerator Conference in Chicago in March was on work in the US, just as the newly instituted European Particle Accelerator Conference places emphasis on work in the 'old continent'. All will come together at the international conference in Japan in August. The proposed US Superconducting Supercollider (SSC) was highlighted in the opening talk at Chicago. Progress on this inchoate project to explore the TeV (1000 GeV) energy region by colliding 20 TeV proton beams was reported by the recently-appointed Director of the SSC Laboratory, Roy Schwitters. He reviewed the physics challenges and described progress and plans towards full authorization of construction.This year, the SSC conceptual design will be transformed into a 'site specific' report, now that the location at Waxahachie in Ellis County, Texas, has been selected. The Central Design Group, based in Berkeley for the past few years, will soon move to the Waxahachie region. The top management structure is taking shape and an International Advisory Committee is being formed
Cosmology and particle physics
International Nuclear Information System (INIS)
Turner, M.S.
1986-01-01
Progress in cosmology has become linked to progress in elementary particle physics. In these six lectures, the author illustrates the two-way nature of the interplay between these fields by focusing on a few selected topics. In the next section the author reviews the standard cosmology, especially concentrating on primordial nucleosynthesis and discusses how the standard cosmology has been used to place constraints on the properties of various particles. Grand Unification makes two striking predictions: (i) B non-conservation; (ii) the existence of stable, superheavy magnetic monopoles. Both have had great cosmological impact. In the following section the author discusses baryogenesis, the very attractive scenario in which the B,C,CP violating interactions in GUTs provide a dynamical explanation for the predominance of matter over antimatter and the present baryon-to-photon ratio. Monopoles are a cosmological disaster and an astrophysicist's delight. In Section 4 discusses monopoles, cosmology, and astrophysics. In the fourth lecture the author discusses how a very early (t≤10/sup -34/ sec) phase transition associated with spontaneous symmetry breaking (SSB) has the potential to explain a handful of very fundamental cosmological facts, facts which can be accommodated by the standard cosmology, but which are not ''explained'' by it. The fifth lecture is devoted to a discussion of structure formation in the universe
International Nuclear Information System (INIS)
1999-01-01
The ability to exhaust the plasma power loss from a large tokamak onto material walls surrounding the plasma has been perceived to be a large obstacle to the successful production of a fusion power reactor in the past. There have been tremendous strides in understanding the physics relevant to this power exhaust over the past five years. This improvement in understanding has arisen because of both improved diagnostics of the plasma outside the last closed flux surface, and because of improved two dimensional computer models of this plasma. This understanding has led to innovative plasma solutions that reduce the power load to the divertor region of ITER to levels that are acceptable for a successful engineering design of the divertors. These plasma solutions have been realized in the devices that are active today. Analysis using the improved plasma models also indicates that particle control, both of fuel and impurity particles, is adequate for successful operation of ITER. This paper presents the current status of both the experimental and theoretical understanding of the plasma, neutral and atomic physics relevant to the plasma at the edge of fusion devices. Since understanding of the subject of this paper is progressing rapidly, we should emphasize that this paper was written in the spring of 1998 and, as such, presents the status of the subject at that time. (author)
Chicago particle accelerator conference
Energy Technology Data Exchange (ETDEWEB)
Southworth, Brian
1989-06-15
Naturally, emphasis at the Particle Accelerator Conference in Chicago in March was on work in the US, just as the newly instituted European Particle Accelerator Conference places emphasis on work in the 'old continent'. All will come together at the international conference in Japan in August. The proposed US Superconducting Supercollider (SSC) was highlighted in the opening talk at Chicago. Progress on this inchoate project to explore the TeV (1000 GeV) energy region by colliding 20 TeV proton beams was reported by the recently-appointed Director of the SSC Laboratory, Roy Schwitters. He reviewed the physics challenges and described progress and plans towards full authorization of construction.This year, the SSC conceptual design will be transformed into a 'site specific' report, now that the location at Waxahachie in Ellis County, Texas, has been selected. The Central Design Group, based in Berkeley for the past few years, will soon move to the Waxahachie region. The top management structure is taking shape and an International Advisory Committee is being formed.
Particle Accelerator Focus Automation
Lopes, José; Rocha, Jorge; Redondo, Luís; Cruz, João
2017-08-01
The Laboratório de Aceleradores e Tecnologias de Radiação (LATR) at the Campus Tecnológico e Nuclear, of Instituto Superior Técnico (IST) has a horizontal electrostatic particle accelerator based on the Van de Graaff machine which is used for research in the area of material characterization. This machine produces alfa (He+) and proton (H+) beams of some μA currents up to 2 MeV/q energies. Beam focusing is obtained using a cylindrical lens of the Einzel type, assembled near the high voltage terminal. This paper describes the developed system that automatically focuses the ion beam, using a personal computer running the LabVIEW software, a multifunction input/output board and signal conditioning circuits. The focusing procedure consists of a scanning method to find the lens bias voltage which maximizes the beam current measured on a beam stopper target, which is used as feedback for the scanning cycle. This system, as part of a wider start up and shut down automation system built for this particle accelerator, brings great advantages to the operation of the accelerator by turning it faster and easier to operate, requiring less human presence, and adding the possibility of total remote control in safe conditions.
Particle Accelerator Focus Automation
Directory of Open Access Journals (Sweden)
Lopes José
2017-08-01
Full Text Available The Laboratório de Aceleradores e Tecnologias de Radiação (LATR at the Campus Tecnológico e Nuclear, of Instituto Superior Técnico (IST has a horizontal electrostatic particle accelerator based on the Van de Graaff machine which is used for research in the area of material characterization. This machine produces alfa (He+ and proton (H+ beams of some μA currents up to 2 MeV/q energies. Beam focusing is obtained using a cylindrical lens of the Einzel type, assembled near the high voltage terminal. This paper describes the developed system that automatically focuses the ion beam, using a personal computer running the LabVIEW software, a multifunction input/output board and signal conditioning circuits. The focusing procedure consists of a scanning method to find the lens bias voltage which maximizes the beam current measured on a beam stopper target, which is used as feedback for the scanning cycle. This system, as part of a wider start up and shut down automation system built for this particle accelerator, brings great advantages to the operation of the accelerator by turning it faster and easier to operate, requiring less human presence, and adding the possibility of total remote control in safe conditions.
Particle physics---Experimental
International Nuclear Information System (INIS)
Lord, J.J.; Boynton, P.E.; Burnett, T.H.; Wilkes, R.J.
1991-01-01
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 ∼ 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
Particle physics experiments, 1991
International Nuclear Information System (INIS)
Roberts, B.A.
1992-01-01
Data taking for this experiment was completed in December 1983. The samples include approximately 19,000 (ν) and 11,000 (ν-bar) charged current events. These constitute the largest data set of interactions on free protons. Work published to date includes studies of inclusive structure functions and final state properties, exclusive final states, neutral current cross sections and production of strange and charmed particles. During the past year results have been published on the production of f 2 (1270) and ν 0 (770) mesons in ρp and ρ-barp charged current interactions. In the case of the f 2 this represents the first observation of such production. It is found that the multiplicities are 0.047±0.017 in ρp and 0.17±0.018 in ρ-barp. The f 2 mesons are mostly produced at large hadronic invariant mass W and in the forward hemisphere. The production of ν 0 mesons can be observed with high statistics in both ρp and ρ-barp interactions and the differential cross section studied. The observations are compared with LUND Monte Carlo predictions, which are generally found to be too high. However qualitative features of the data are reproduced. Work continues on a precise determination of the neutral current/charged current ratio, on the study of charged and neutral current structure functions and on the production of strange particles. (author)
Modern Elementary Particle Physics
Kane, Gordon
2017-02-01
1. Introduction; 2. Relativistic notation, Lagrangians, and interactions; 3. Gauge invariance; 4. Non-abelian gauge theories; 5. Dirac notation for spin; 6. The Standard Model Lagrangian; 7. The electroweak theory and quantum chromodynamics; 8. Masses and the Higgs mechanism; 9. Cross sections, decay widths, and lifetimes: W and Z decays; 10. Production and properties of W± and Zᴼ; 11. Measurement of electroweak and QCD parameters: the muon lifetime; 12. Accelerators - present and future; 13. Experiments and detectors; 14. Low energy and non-accelerator experiments; 15. Observation of the Higgs boson at the CERN LHC: is it the Higgs boson?; 16. Colliders and tests of the Standard Model: particles are pointlike; 17. Quarks and gluons, confinement and jets; 18. Hadrons, heavy quarks, and strong isospin invariance; 19. Coupling strengths depend on momentum transfer and on virtual particles; 20. Quark (and lepton) mixing angles; 21. CP violation; 22. Overview of physics beyond the Standard Model; 23. Grand unification; 24. Neutrino masses; 25. Dark matter; 26. Supersymmetry.
Stalking the ultimate particle
2003-01-01
If you missed the ARTE programme entitled "L'Ultime Particule" broadcast in February, you have another chance to catch it in CERN's Main Auditorium on 13 March. "L'Ultime Particule" is a documentary by the French director Michel Andrieu that seeks to explain particle physics through a contemplative quest for the research physicists of matter of today and yesteryear. Invariably kitted out in a red parka and a soft hat, the programme's investigator scours the planet and the archives in search of the research physicists who are stalking the ultimate particle, the Higgs boson, in their quest to understand the structure of matter. Naturally enough, CERN is an important stage of his journey where Michel Andrieu and his team spent several days last year. Both from the physics and metaphysical points of view, "L'Ultime Particule" is worth seeing. The film's director, Michel Andrieu, will introduce his documentary and answer questions from the audience after the documentary has been shown. L'Ultime Particule by Mic...
Classification of new particles
International Nuclear Information System (INIS)
Karl, G.
1976-01-01
A classification of the new particles is proposed. Hadrons are constructed from quarks corresponding to several different representations of an SU 3 color group, with confined color. The new family of resonances, related to psi/J, is assigned to color-antisextet quarks Q. These new quarks Q do not form mixed mesons q-barQ with old antiquarks but can form mixed baryons Qqq. We speculate on the relation between color and mass. High-mass recurrences of the psi/J family are expected to have associated large changes in the cross section for electron-positron annihilation (ΔR > 4). A conjectured mass formula, which relates the masses of psi/J and ω, predicts the masses of possible recurrences of the psi/J particle. Other experimental implications at presently available energies are discussed, especially the necessity for an isovector partner for psi/J, and for pseudoscalar mesons at 1.8--2.2 GeV, some of which can decay into two photons
Analysis of particle kinematics in spheronization via particle image velocimetry.
Koester, Martin; Thommes, Markus
2013-02-01
Spheronization is a wide spread technique in pellet production for many pharmaceutical applications. Pellets produced by spheronization are characterized by a particularly spherical shape and narrow size distribution. The particle kinematic during spheronization is currently not well-understood. Therefore, particle image velocimetry (PIV) was implemented in the spheronization process to visualize the particle movement and to identify flow patterns, in order to explain the influence of various process parameters. The spheronization process of a common formulation was recorded with a high-speed camera, and the images were processed using particle image velocimetry software. A crosscorrelation approach was chosen to determine the particle velocity at the surface of the pellet bulk. Formulation and process parameters were varied systematically, and their influence on the particle velocity was investigated. The particle stream shows a torus-like shape with a twisted rope-like motion. It is remarkable that the overall particle velocity is approximately 10-fold lower than the tip speed of the friction plate. The velocity of the particle stream can be correlated to the water content of the pellets and the load of the spheronizer, while the rotation speed was not relevant. In conclusion, PIV was successfully applied to the spheronization process, and new insights into the particle velocity were obtained. Copyright © 2012 Elsevier B.V. All rights reserved.
Four-particle scattering with three-particle interactions
International Nuclear Information System (INIS)
Adhikari, S.K.
1979-01-01
The four-particle scattering formalism proposed independently by Alessandrini, by Mitra et al., by Rosenberg, and by Takahashi and Mishima is extended to include a possible three-particle interaction. The kernel of the new equations we get contain both two- and three-body connected parts and gets four-body connected after one iteration. On the other hand, the kernel of the original equations in the absence of three-particle interactions does not have a two-body connected part. We also write scattering equations for the transition operators connecting the two-body fragmentation channels. They are generalization of the Sloan equations in the presence of three-particle interactions. We indicate how to include approximately the effect of a weak three-particle interaction in a practical four-particle scattering calculation
Particle Image Velocimetry Applications of Fluorescent Dye-Doped Particles
Petrosky, Brian Joseph
2015-01-01
Laser flare can often be a major issue in particle image velocimetry (PIV) involving solid boundaries in a flow or a gas-liquid interface. The use of fluorescent light from dye-doped particles has been demonstrated in water applications, but reproducing the technique in an airflow is more difficult due to particle size constraints and safety concerns. The following thesis is formatted in a hybrid manuscript style, including a full paper presenting the applications of fluorescent Kiton R...
Particle supply and recovery device
International Nuclear Information System (INIS)
Yamada, Kimio; Okazaki, Takashi.
1988-01-01
This invention concerns a particle supply and recovery device suitable to the supply of fuels and exhaustion of reaction products in a tokamak device. The divertor chamber is divided into an inner side and an outer side, in which only the outer side is constituted as a tightly closed structure. Particles are supplied from the inside of main plasmas and exhausted from the outer side of the divertor chamber. In the divertor equilibrium arrangement, particles escaping from the main plasmas are conveyed mainly passing through the outer side scrape-off layer to the divertor chamber. The particle density is higher at the outer side and lower at the inner side of the scrape-off layer. By making the outer side as a tightly closed structure, the pressure is increased and the particle exhaustion efficiency is improved. Since the particle density is low in the inner scrape-layer, the particle supply efficiency to the main plasma is increased by supplying the particles from the inside. Further, particles ionized in the inner scrape-off layer are returned to the main plasma chamber and then supplied again since the inner divertor chamber is not closed. Accordingly, the particle supply efficiency can further be improved. (K.M.)
Particle separations by electrophoretic techniques
International Nuclear Information System (INIS)
Ballou, N.E.; Petersen, S.L.; Ducatte, G.R.; Remcho, V.T.
1996-03-01
A new method for particle separations based on capillary electrophoresis has been developed and characterized. It uniquely separates particles according to their chemical nature. Separations have been demonstrated with chemically modified latex particles and with inorganic oxide and silicate particles. Separations have been shown both experimentally and theoretically to be essentially independent of particle size in the range of about 0.2 μm to 10 μm. The method has been applied to separations of U0 2 particles from environmental particulate material. For this, an integrated method was developed for capillary electrophoretic separation, collection of separated fractions, and determinations of U0 2 and environmental particles in each fraction. Experimental runs with the integrated method on mixtures of UO 2 particles and environmental particulate material demonstrated enrichment factors of 20 for UO 2 particles in respect to environmental particles in the U0 2 containing fractions. This enrichment factor reduces the costs and time for processing particulate samples by the lexan process by a factor of about 20
Classical relativistic constituent particles and composite-particle scattering
International Nuclear Information System (INIS)
King, M.J.
1984-01-01
A nonlocal Lagrangian formalism is developed to describe a classical many-particle system. The nonstandard Lagrangian is a function of a single parameter s which is not, in general, associated with the physical clock. The particles are constrained to be constituents of composite systems, which in turn can decompose into asymptotic composite states representing free observable particles. To demonstrate this, explicit models of composite-composite particle scattering are constructed. Space-time conservation laws are not imposed separately on the system, but follow upon requiring the constituents to ''pair up'' into free composites at s = +infinity,-infinity. One model is characterized by the appearance of an ''external'' zero-mass composite particle which participates in the scattering process without affecting the space-time conservation laws of the two-composite system. Initial conditions on the two incoming composite particles and the zero-mass participant determine the scattering angle and the final states of the two outgoing composite particles. Although the formalism is classical, the model displays some features usually associated with quantum field theory, such as particle scattering by means of constituent exchange, creation and annihilation of particles, and restriction of values of angular momentum
Polarization particle drift and quasi-particle invariants
International Nuclear Information System (INIS)
Sosenko, P.P.
1995-01-01
The second-order approximation in quasi-particle description of magnetized plasmas is studied. Reduced particle and guiding-centre velocities are derived taking account of the second-order renormalization and polarization drift modified owing to finite-Larmor-radius effects. The second-order adiabatic invariant of quasi-particle motion is found. Global adiabatic invariants for the magnetized plasma are revealed, and their possible role in energy exchange between particles and fields, nonlinear mode cascades and global plasma stability is shown. 49 refs
International Nuclear Information System (INIS)
2004-01-01
The present collection of letters from JINR, Dubna, contains nine separate letters on data on elastic (p,n) charge exchange: compilation, the potentialities of δ-electron control of luminosity in experiments with internal targets at the Nuclotron, pion broadening and low-mass dilepton production, fluctuation of electromagnetic cascade axis in dense amorphous segmented media, the forward detector of the ANKE spectrometer. Tracking system and its use in data analysis, quantum field theory with three-dimensional vector time, curvature decomposition and the Einstein-Yang-Mills equations, an integral equation for the spinor amplitude of a massive neutral Dirac particle in a curved space time with arbitrary geometry and surprising resonances in 147 Sm(nα) 144 Nd reaction
International Nuclear Information System (INIS)
Ledernman, L.; Teresi, D.; Charpak, G.
1996-09-01
This book is devoted to one problem, a problem that has confounded science since antiquity. What are the ultimate building blocks of matter? In the different chapters the history of the understanding of the structure of matter is presented and seen through the eyes of discoverers. This book is full of anecdotes about the real conditions in which new and bright ideas have emerged. About half of the book is dedicated to modern physics that is to say particle physics, the path followed by physicists to postulate the existence of the Higgs boson is explained. This boson appears to be so central to the state of physics today, so crucial to the final understanding of what matter is and how the universe works, that its experimental discovery will be a true relief. (A.C.)
International Nuclear Information System (INIS)
Johnson, W.L.; Crane, J.K.; Hendricks, C.D.
1980-01-01
Advanced target designs require thicker (approx. 300 μm) coatings and better surface finishes that can be produced with current coating techniques. An advanced coating technique is proposed to provide maximum control of the coating flux and optimum manipulation of the shell during processing. In this scheme a small beam of ions or particles of known incident energy are collided with a levitated spherical mandrel. Precise control of the incident energy and angle of the deposition flux optimizes the control of the coating morphology while controlled rotation and noncontact support of the shell minimizes the possibility of particulate or damage generated defects. Almost infinite variability of the incident energy and material in this process provides increased flexibility of the target designs which can be physically realized
[Medium energy particle physics
International Nuclear Information System (INIS)
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 3 H, 3 He, 4 He; Detailed Balance in pd right reversible γ 3 H; Interaction Dynamics); and Search for the Rare Decay Μ + → e + + γ (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
International Nuclear Information System (INIS)
Steinberg, R.I.; Lane, C.E.
1992-09-01
The goals of this research are the experimental testing of fundamental theories of physics beyond the standard model and the exploration of cosmic phenomena through the techniques of particle physics. We are working on the MACRO experiment, which employs a large-area underground detector to search fore grand unification magnetic monopoles and dark matter candidates and to study cosmic ray muons as well as low- and high-energy neutrinos; the Chooz experiment to search for reactor neutrino oscillations at a distance of 1 km from the source; a new proposal (the Perry experiment) to construct a one-kiloton liquid scintillator in the Fairport, Ohio underground facility IMB to study neutrino oscillations with a 13 km baseline; and development of technology for improved liquid scintillators and for very-low-background materials in support of the MACRO and Perry experiments and for new solar neutrino experiments
International Nuclear Information System (INIS)
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
Monique Duval
2002-01-01
Paul Kunz will be giving his very popular and highly recommended C++ course again on 22-26 July (6 * 3 hour lectures). The course is organised by the CERN Technical Training Programme, it costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page, accessible from the Technical Training pages. Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.
2003-01-01
Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 10 - 14 March. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://cern.ch/TechnicalTraining/ENSTEC/p2002/Software/cpppp_e.asp Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.
Monique Duval
2002-01-01
Paul Kunz will be giving his very popular and highly recommended C++ course again on 22-26 July (6 * 3 hour lectures). The course is organised by the CERN Technical Training Programme, it costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page, accessible from the Technical Training pages. Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.
Technical Training; Tel. 74924
2001-01-01
Paul Kunz will be giving his very popular and highly recommended C++ course again on 8 - 12 October. The course costs 200 CHF, and advance registration is required. Please note that this will be the last session in 2001 and the next one is planned for March 2002. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://www.cern.ch/Training/ENSTEC/P2001/Software/cpppp_e.htm Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.
TECHNICAL TRAINING; Tel. 74460
2001-01-01
Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on March 5 to 9. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://www.cern.ch/Training/ENSTEC/P9798/Software/cpppp_e.htm Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.
Kleinert, Hagen
2016-01-01
This is an introductory book on elementary particles and their interactions. It starts out with many-body Schrödinger theory and second quantization and leads, via its generalization, to relativistic fields of various spins and to gravity. The text begins with the best known quantum field theory so far, the quantum electrodynamics of photon and electrons (QED). It continues by developing the theory of strong interactions between the elementary constituents of matter (quarks). This is possible due to the property called asymptotic freedom. On the way one has to tackle the problem of removing various infinities by renormalization. The divergent sums of infinitely many diagrams are performed with the renormalization group or by variational perturbation theory (VPT). The latter is an outcome of the Feynman-Kleinert variational approach to path integrals discussed in two earlier books of the author, one representing a comprehensive treatise on path integrals, the other dealing with critial phenomena. Unlike ordin...
Sequential charged particle reaction
International Nuclear Information System (INIS)
Hori, Jun-ichi; Ochiai, Kentaro; Sato, Satoshi; Yamauchi, Michinori; Nishitani, Takeo
2004-01-01
The effective cross sections for producing the sequential reaction products in F82H, pure vanadium and LiF with respect to the 14.9-MeV neutron were obtained and compared with the estimation ones. Since the sequential reactions depend on the secondary charged particles behavior, the effective cross sections are corresponding to the target nuclei and the material composition. The effective cross sections were also estimated by using the EAF-libraries and compared with the experimental ones. There were large discrepancies between estimated and experimental values. Additionally, we showed the contribution of the sequential reaction on the induced activity and dose rate in the boundary region with water. From the present study, it has been clarified that the sequential reactions are of great importance to evaluate the dose rates around the surface of cooling pipe and the activated corrosion products. (author)
Supersymmetry of elementary particles
International Nuclear Information System (INIS)
Sardanashvili, G.A.; Zakharov, O.A.
1986-01-01
Some difficulties, connected with correct application of supersymmetry mathematical tools in the field and elementary particle theory are pointed out. The role of Grassman algebra in the usual field theory and the role of Lee superalgebra in supertransformations mixing bosons and fermions are shown. Grassman algebra in the theory of supersymmetries plays a role of numerical field. A supersymmetrical model, when indexes {i} of Grassman algebra corresponding to ''color'', and indexes {α} of Lee superalgebra representations - to ''flavor'', is considered. It is marked that the problem of interpretation of Grassman algebra indexes is a key one for the theory of supersymmetries. In particular, it gives no possibility to come from the theory of supersymmetries to the usual field theory, whose indexes of Grassman algebra possess obvious physical meaning
International Nuclear Information System (INIS)
2004-01-01
The present collection of letters from JINR, Dubna, contains eight separate letters on analysis of experimental data on relativistic nuclear collisions in the Lobachevski space, relativistic contribution of the final-state interaction to deuteron photodisintegration, on the charge asymmetry of the like-sign lepton pairs induced by B - B bar - production asymmetry, limits on the ν e → ν e neutrino oscillation parameters from an experiment at the IHEP-JINR neutrino detector, excitation of high spin isomers in photonuclear reactions, study of product formation in proton-nuclear reactions on the 129 I target induced by 660-MeV protons, application of jet pumps in the cryogenic system of the Nuclotron - superconducting accelerator of relativistic particles and study of the silicon drift detector performance with inclined tracks
International Nuclear Information System (INIS)
Salam, A.
1986-02-01
An overview of the situation of particle physics at the end of 1985 is given. It includes the following topics: ideas which have been tested or will soon be tested such as the standard model based on the symmetry group SUsub(C)(3)xSUsub(L)(2)xU(1), light Higgs and preons; theoretical ideas whose time has not yet come (basically because no accelerators are being constructed to test them) such as N=1 supersymmetry and N=1 supergravity right-handed weak currents, extended supergravities and superstring models; ideas for which non-accelerator and passive experiments have been mounted such as proton decay, nn-bar oscillations, neutrino masses and oscillations, monopoles and dark matter
Monique Duval
2004-01-01
Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 15 ï¿½- 19 November. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page: Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent. ENSEIGNEMENT TECHNIQUE TECHNICAL TRAINING Monique Duval 74924 technical.training@cern.ch
Monique Duval
2004-01-01
Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 15 - 19 November. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page: Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent. ENSEIGNEMENT TECHNIQUE TECHNICAL TRAINING Monique Duval 74924 technical.training@cern.ch
International Nuclear Information System (INIS)
2004-01-01
The present collection of letters from JINR, Dubna, contains nine separate letters on nonlocal chiral quark model with confinement, perturbation of finite-lattice spectral levels by nearby nuclear resonances, on the application of 'Z 0 + jet' events for determining the gluon distribution in a proton at the LHC, account of light velocity constancy in the Galilean problem on the free movement of a particle and its fall onto the ground, first results of crystal deflector investigations at the Nuclotron external beams, decay parameters of K mesons, measured at proton synchrotron U-70 using 'Hyperon' set-up and modern world data, prototype of atomic-emission spectrometer on the basis of one-electrode impulse RF discharge for analytical measurements, polarimeter for Nuclotron internal beam and primordial bubbles of colour superconducting quark matter
International Nuclear Information System (INIS)
Mansouri, F.; Suranyi, P.; Wijewardhana, L.C.R.; Witten, L.
1990-10-01
A 2+1 dimensional deSitter Chern-Simons theory has been constructed and shown to be consistent. Wilson loop variables have been computed and shown to close under Poisson bracket operation for N = 2 Poincare supergravity. It has also been shown that there are two equivalent pictures of describing two particle scattering in 2+1 dimensional gravity theory, which are related by multivalued gauge transformations. We have generalized the Jackiw-Johnson sumrule, relating Goldstone boson decay constants to the dynamical masses of fermions, to an arbitrary symmetry group. We have analyzed dynamical parity breaking in 2+1 dimensional 4-fermi theories. Finally, we have found the partition function for a system of free parabosons and parafermions of order two. 53 refs
Particle processing technology
Sakka, Yoshio
2014-02-01
In recent years, there has been strong demand for the development of novel devices and equipment that support advanced industries including IT/semiconductors, the environment, energy and aerospace along with the achievement of higher efficiency and reduced environmental impact. Many studies have been conducted on the fabrication of innovative inorganic materials with novel individual properties and/or multifunctional properties including electrical, dielectric, thermal, optical, chemical and mechanical properties through the development of particle processing. The fundamental technologies that are key to realizing such materials are (i) the synthesis of nanoparticles with uniform composition and controlled crystallite size, (ii) the arrangement/assembly and controlled dispersion of nanoparticles with controlled particle size, (iii) the precise structural control at all levels from micrometer to nanometer order and (iv) the nanostructural design based on theoretical/experimental studies of the correlation between the local structure and the functions of interest. In particular, it is now understood that the application of an external stimulus, such as magnetic energy, electrical energy and/or stress, to a reaction field is effective in realizing advanced particle processing [1-3]. This special issue comprises 12 papers including three review papers. Among them, seven papers are concerned with phosphor particles, such as silicon, metals, Si3N4-related nitrides, rare-earth oxides, garnet oxides, rare-earth sulfur oxides and rare-earth hydroxides. In these papers, the effects of particle size, morphology, dispersion, surface states, dopant concentration and other factors on the optical properties of phosphor particles and their applications are discussed. These nanoparticles are classified as zero-dimensional materials. Carbon nanotubes (CNT) and graphene are well-known one-dimensional (1D) and two-dimensional (2D) materials, respectively. This special issue also
Associated particle imaging (API)
International Nuclear Information System (INIS)
1998-05-01
Associated Particle Imaging (API) is an active neutron probe technique that provides a 3-D image with elemental composition of the material under interrogation, and so occupies a unique niche in the interrogation of unknown objects. The highly penetrating nature of neutrons enables API to provide detailed information about targets of interest that are hidden from view. Due to the isotropic nature of the induced reactions, radiation detectors can be set on the same side of the object as the neutron source, so that the object can be interrogated from a single side. At the heat of the system is a small generator that produces a continuous, monoenergetic flux of neutrons. By measuring the trajectory of coincident alpha particles that are produced as part of the process, the trajectory of the neutron can be inferred. Interactions between a neutron and the material in its path often produce a gamma ray whose energy is characteristic of that material. When the gamma ray is detected, its energy is measured and combined with the trajectory information to produce a 3-D image of the composition of the object being interrogated. During the course of API development, a number of improvements have been made. A new, more rugged sealed Tube Neutron Generator (STNG) has been designed and fabricated that is less susceptible to radiation damage and better able to withstand the rigors of fielding than earlier designs. A specialized high-voltage power supply for the STNG has also been designed and built. A complete package of software has been written for the tasks of system calibration, diagnostics and data acquisition and analysis. A portable system has been built and field tested, proving that API can be taken out of the lab and into real-world situations, and that its performance in the field is equal to that in the lab
Particle acceleration by pulsars
International Nuclear Information System (INIS)
Arons, Jonathan.
1980-06-01
The evidence that pulsars accelerate relativistic particles is reviewed, with emphasis on the γ-ray observations. The current state of knowledge of acceleration in strong waves is summarized, with emphasis on the inability of consistent theories to accelerate very high energy particles without converting too much energy into high energy photons. The state of viable models for pair creation by pulsars is summarized, with the conclusion that pulsars very likely lose rotational energy in winds instead of in superluminous strong waves. The relation of the pair creation models to γ-ray observations and to soft X-ray observations of pulsars is outlined, with the conclusion that energetically viable models may exist, but none have yet yielded useful agreement with the extant data. Some paths for overcoming present problems are discussed. The relation of the favored models to cosmic rays is discussed. It is pointed out that the pairs made by the models may have observable consequences for observation of positrons in the local cosmic ray flux and for observations of the 511 keV line from the interstellar medium. Another new point is that asymmetry of plasma supply from at least one of the models may qualitatively explain the gross asymmetry of the X-ray emission from the Crab nebula. It is also argued that acceleration of cosmic ray nuclei by pulsars, while energetically possible, can occur only at the boundary of the bubbles blown by the pulsars, if the cosmic ray composition is to be anything like that of the known source spectrum
Spin analysis of supersymmetric particles
International Nuclear Information System (INIS)
Choi, S.Y.; Martyn, H.U.
2006-12-01
The spin of supersymmetric particles can be determined at e + e - colliders unambiguously. This is demonstrated for a characteristic set of non-colored supersymmetric particles -- smuons, selectrons, and charginos/neutralinos. The analysis is based on the threshold behavior of the excitation curves for pair production in e + e - collisions, the angular distribution in the production process and decay angular distributions. In the first step we present the observables in the helicity formalism for the supersymmetric particles. Subsequently we confront the results with corresponding analyses of Kaluza-Klein particles in theories of universal extra space dimensions which behave distinctly different from supersymmetric theories. It is shown in the third step that a set of observables can be designed which signal the spin of supersymmetric particles unambiguously without any model assumptions. Finally in the fourth step it is demonstrated that the determination of the spin of supersymmetric particles can be performed experimentally in practice at an e + e - collider. (orig.)
Particle effects on fish gills
DEFF Research Database (Denmark)
Lu, Cao; Kania, Per W.; Buchmann, Kurt
2018-01-01
Particles composed of inorganic, organic and/or biological materials occur in both natural water bodies and aquaculture facilities. They are expected to affect fish health through a direct chemical, mechanical and biological interaction with gills during ventilation but the nature of the reactions...... and the relative importance of mechanical versus chemical and biological stimulation are unknown. The present work presents an immune gene expression method for evaluation of gill disturbance and sets a baseline for the mechanical influence on fish gills of chemically inert spherical particles. The method may...... be applied to investigate particle impact at different combinations of temperature, fish size, water quality and particle composition. Spherical polystyrene particles (diameters 0.2 μm, 1 μm, 20 μm, 40 μm and 90 μm) were adopted as the particle model and the rainbow trout (Oncorhynchus mykiss) fingerlings...
Optical Particle Characterization in Flows
Tropea, Cameron
2011-01-01
Particle characterization in dispersed multiphase flows is important in quantifying transport processes both in fundamental and applied research: Examples include atomization and spray processes, cavitation and bubbly flows, and solid particle transport in gas and liquid carrier phases. Optical techniques of particle characterization are preferred owing to their nonintrusiveness, and they can yield information about size, velocity, composition, and to some extent the shape of individual particles. This review focuses on recent advances for measuring size, temperature, and the composition of particles, including several planar methods, various imaging techniques, laser-induced fluorescence, and the more recent use of femtosecond pulsed light sources. It emphasizes the main sources of uncertainty, the achievable accuracy, and the outlook for improvement of specific techniques and for specific applications. Some remarks are also directed toward the computational tools used to design and investigate the performance of optical particle diagnostic instruments.
International Nuclear Information System (INIS)
Gamboa, J.; Rivelles, V.O.
1989-02-01
We study spinning self-dual particles in two dimensions. They are obtained from the chiral bosonic particle through the square root technique. We show that the resulting field theory can be either fermionic or bosonic and that the associated self-dual field reveals its Lorentz tensor structure which remains hidden in the usual formulations. We also calculate the spinning self-dual particle propagators using the BFV formalism. (author) [pt
Particle Dark Matter: An Overview
International Nuclear Information System (INIS)
Roszkowski, Leszek
2009-01-01
Dark matter in the Universe is likely to be made up of some new, hypothetical particle which would be a part of an extension of the Standard Model of particle physics. In this overview, I will first briefly review well motivated particle candidates for dark matter. Next I will focus my attention on the neutralino of supersymmetry which is the by far most popular dark matter candidate. I will discuss some recent progress and comment on prospects for dark matter detection.
Health Benefits of Particle Filtration
Fisk, William J.
2013-01-01
The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and as...
Aspects of experimental particle physics
International Nuclear Information System (INIS)
McCubbin, N.A.
1986-11-01
The paper contains three lectures on Experimental Particle Physics which were given at the 16th British Universities Summer School for Theoretical and Elementary Particle Physics, Durham, 1986. The first lecture briefly reviews the physics which underpins all particle detectors, and the second lecture describes how this physics influences a modern detector. The last lecture is concerned with the topics of beams and computers, and includes the physics of stochastic cooling and the Halting theorem. (U.K.)
A spectrometer for submicron particles
International Nuclear Information System (INIS)
Pourprix, M.
1995-01-01
The electrostatic spectrometer for aerosol particles, is composed of two coaxial parallel conductive disks between which an electric field is established; an annular slot in the first disk allows for the atmosphere air intake. Suction and injection systems, and a third intermediate conductive disk are used to carry out a dynamic confinement that allows for the separation of particles having various electronic mobility and the determination of the suspended particle size distribution. Application to aerosol size spectrum determination and air quality monitoring
Dispersion of Bed Load Particles
SAWAI, Kenji
1987-01-01
The motion of bed load particles is so irregular that they disperse remarkably with time.In this study, some flume tests using painted tracer particles were carried out, in which thedispersive property of tracers changed variously with sediment feed rate.In analysing this process, a stochastic simulation model is proposed where it is discussedabout the degree of exposure of individual particle near the bed surface and about the variationof its pick up rate. The exponential distribution of ste...
Amorphous silicon based particle detectors
Wyrsch, N.; Franco, A.; Riesen, Y.; Despeisse, M.; Dunand, S.; Powolny, F.; Jarron, P.; Ballif, C.
2012-01-01
Radiation hard monolithic particle sensors can be fabricated by a vertical integration of amorphous silicon particle sensors on top of CMOS readout chip. Two types of such particle sensors are presented here using either thick diodes or microchannel plates. The first type based on amorphous silicon diodes exhibits high spatial resolution due to the short lateral carrier collection. Combination of an amorphous silicon thick diode with microstrip detector geometries permits to achieve micromete...
Quark matter or new particles?
Michel, F. Curtis
1988-01-01
It has been argued that compression of nuclear matter to somewhat higher densities may lead to the formation of stable quark matter. A plausible alternative, which leads to radically new astrophysical scenarios, is that the stability of quark matter simply represents the stability of new particles compounded of quarks. A specific example is the SU(3)-symmetric version of the alpha particle, composed of spin-zero pairs of each of the baryon octet (an 'octet' particle).
Schikora, Marek; Gning, Amadou; Mihaylova, Lyudmila; Cremers, Daniel; Koch, Wofgang; Streit, Roy
2012-01-01
This paper develops a novel approach for multi-target tracking, called box-particle intensity filter (box-iFilter). The approach is able to cope with unknown clutter, false alarms and estimates the unknown number of targets. Furthermore, it is capable of dealing with three sources of uncertainty: stochastic, set-theoretic and data association uncertainty. The box-iFilter reduces the number of particles significantly, which improves the runtime considerably. The low particle number enables thi...
Particle Analysis in Forensic Science.
Bisbing, R E; Schneck, W M
2006-07-01
Microscopic trace evidence includes particles from many sources such as biologicals, soil, building materials, metals, explosives, gunshot residues, and cosmetics. The particles are identified by morphological analysis, microscopy, and chemical analysis. Their identity is confirmed by comparison with reference materials or other comparison samples. The probative value of particles of forensic interest depends on their nature and the circumstances of their presence. Copyright © 2006 Central Police University.
Photocatalytic/Magnetic Composite Particles
Wu, Chang-Yu; Goswami, Yogi; Garretson, Charles; Andino, Jean; Mazyck, David
2007-01-01
Photocatalytic/magnetic composite particles have been invented as improved means of exploiting established methods of photocatalysis for removal of chemical and biological pollutants from air and water. The photocatalytic components of the composite particles are formulated for high levels of photocatalytic activity, while the magnetic components make it possible to control the movements of the particles through the application of magnetic fields. The combination of photocatalytic and magnetic properties can be exploited in designing improved air- and water treatment reactors.
A Parallel Particle Swarm Optimizer
National Research Council Canada - National Science Library
Schutte, J. F; Fregly, B .J; Haftka, R. T; George, A. D
2003-01-01
.... Motivated by a computationally demanding biomechanical system identification problem, we introduce a parallel implementation of a stochastic population based global optimizer, the Particle Swarm...
Particle transport in porous media
Corapcioglu, M. Yavuz; Hunt, James R.
The migration and capture of particles (such as colloidal materials and microorganisms) through porous media occur in fields as diversified as water and wastewater treatment, well drilling, and various liquid-solid separation processes. In liquid waste disposal projects, suspended solids can cause the injection well to become clogged, and groundwater quality can be endangered by suspended clay and silt particles because of migration to the formation adjacent to the well bore. In addition to reducing the permeability of the soil, mobile particles can carry groundwater contaminants adsorbed onto their surfaces. Furthermore, as in the case of contamination from septic tanks, the particles themselves may be pathogens, i.e., bacteria and viruses.
Aging fingerprints in combustion particles
Zelenay, V.; Mooser, R.; Tritscher, T.; Křepelová, A.; Heringa, M. F.; Chirico, R.; Prévôt, A. S. H.; Weingartner, E.; Baltensperger, U.; Dommen, J.; Watts, B.; Raabe, J.; Huthwelker, T.; Ammann, M.
2011-05-01
Soot particles can significantly influence the Earth's climate by absorbing and scattering solar radiation as well as by acting as cloud condensation nuclei. However, despite their environmental (as well as economic and political) importance, the way these properties are affected by atmospheric processing is still a subject of discussion. In this work, soot particles emitted from two different cars, a EURO 2 transporter, a EURO 3 passenger vehicle, and a wood stove were investigated on a single-particle basis. The emitted exhaust, including the particulate and the gas phase, was processed in a smog chamber with artificial solar radiation. Single particle specimens of both unprocessed and aged soot were characterized using x-ray absorption spectroscopy and scanning electron microscopy. Comparison of the spectra from the unprocessed and aged soot particles revealed changes in the carbon functional group content, such as that of carboxylic carbon, which can be ascribed to both the condensation of secondary organic compounds on the soot particles and oxidation of primary soot particles upon photochemical aging. Changes in the morphology and size of the single soot particles were also observed upon aging. Furthermore, we show that the soot particles take up water in humid environments and that their water uptake capacity increases with photochemical aging.
Diesel particles - a health hazard
Energy Technology Data Exchange (ETDEWEB)
Ege, C.
2004-08-15
To all appearances, small particles belong to the pollutants presenting the biggest health hazards. Particles come especially from diesel-powered vehicles. According to researchers, particles cause thousands of early deaths each year in the big cities in Denmark alone, and up to 1,250 of these deaths could be prevented by fitting particle filters on diesel-powered vehicles. That is more than deaths caused by traffic accidents. Especially the elderly are affected. In addition, the small particles seem to aggravate asthma incidences, including the many children with asthma. What makes the small particles so very dangerous is that they can enter the smallest of vessels of the lungs. There is a solution within sight to this grave health hazard. The solution is called particle filters, but they will not come automatically. It requires initiatives in the form of legislation, green taxes and subsidies. The EU is introducing stricter regulations regarding particle emission from heavy vehicles from 2006, though only for new vehicles. It will therefore take many years to abate the problem this way. In the present pamphlet, the Danish Ecological Council offers a number of specific proposals on how to further the introduction of filters on diesel vehicles. The Danish government has taken a small step in the right direction by establishing a subsidy scheme for particle filters. Yet the amount allocated is too small and, because it is not followed up by setting taxes on polluting vehicles, it will have little effect. (au)
Rain scavenging of radioactive particles
International Nuclear Information System (INIS)
Williams, A.L.
1975-01-01
An assessment is made of the rainout of airborne radioactive particles from a nuclear detonation with emphasis on the microphysical removal processes. For submicron particles the scavenging processes examined are Brownian and turbulent diffusion to cloud droplets. For particles larger than 1 μm radius, nucleation scavenging is examined. For various particle size and radioactivity distributions, it is found that from 27 to 99 percent of the radioactivity is attached to cloud droplets and subject to rapid removal by rain. (U.S.)
Effective particle magnetic moment of multi-core particles
Ahrentorp, F.; Astalan, A.; Blomgren, J.; Jonasson, C.; Wetterskog, E.; Svedlindh, P.; Lak, A.; Ludwig, F.; Van IJzendoorn, L.J.; Westphal, F.; Grüttner, C.; Gehrke, N.; Gustafsson, S.; Olsson, E.; Johansson, C.
2015-01-01
In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron
Particle deposition in ventilation ducts
Energy Technology Data Exchange (ETDEWEB)
Sippola, Mark Raymond [Univ. of California, Berkeley, CA (United States)
2002-09-01
Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 μm were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the
Saint-Michel, Brice; Georgelin, Marc; Deville, Sylvain; Pocheau, Alain
2017-06-13
The interaction of solidification fronts with objects such as particles, droplets, cells, or bubbles is a phenomenon with many natural and technological occurrences. For an object facing the front, it may yield various fates, from trapping to rejection, with large implications regarding the solidification pattern. However, whereas most situations involve multiple particles interacting with each other and the front, attention has focused almost exclusively on the interaction of a single, isolated object with the front. Here we address experimentally the interaction of multiple particles with a solidification front by performing solidification experiments of a monodisperse particle suspension in a Hele-Shaw cell with precise control of growth conditions and real-time visualization. We evidence the growth of a particle layer ahead of the front at a close-packing volume fraction, and we document its steady-state value at various solidification velocities. We then extend single-particle models to the situation of multiple particles by taking into account the additional force induced on an entering particle by viscous friction in the compacted particle layer. By a force balance model this provides an indirect measure of the repelling mean thermomolecular pressure over a particle entering the front. The presence of multiple particles is found to increase it following a reduction of the thickness of the thin liquid film that separates particles and front. We anticipate the findings reported here to provide a relevant basis to understand many complex solidification situations in geophysics, engineering, biology, or food engineering, where multiple objects interact with the front and control the resulting solidification patterns.
International Nuclear Information System (INIS)
Depasse, P.
2004-11-01
This document reports the work made by the author in the field of the improvement of gamma detection. The first part is dedicated to experiments and testing performed at the nuclear physics institute in Lyon. It deals with photo-sensors, avalanche photo-diodes and drift chambers. The second part presents the implementation of active lead rings (ALR) to the L3 detector. Although ALR cover only a hundredth of the total solid angle, they are useful for detecting events in which one or several particles bring away a large part of the momentum in a strongly forward direction (between 4 and 9 degrees). The third part is dedicated to the design of the electromagnetic calorimeter barrel that will equip the CMS (compact muon solenoid) that is due to operate on the large hadron collider (LHC). The work made for the selection of scintillating materials (cerium fluoride, lead tungstate), of photo-sensors and for the design of front electronic equipment is particularly detailed. The last part is dedicated to how the knowledge cumulated about photon detection could be beneficial for medical imaging, particularly for the detection of 511 keV photon released in positron collisions. (A.C.)
International Nuclear Information System (INIS)
Kenyon, I.R.
1987-01-01
Intended for undergraduate and postgraduate students the book concentrates on the 'standard model' and the gauge symmetries. Leptons, quarks and forces are introduced at the beginning, followed by experimental techniques which have found them. Gauge theories are dealt with in order of increasing complexity - quantum electrodynamics and the gauge principle, symmetries and conservation laws, colour and quantum chromodynamics, the V - A theory of weak interactions and electroweak unification. Attention is then focussed on the hadrons. Deep inelastic scattering of hadrons is explained first, then hadron spectroscopy and then hadron interactions. Current developments beyond the Standard model - grand unification, supersymmetry, cosmology and gravitation -are discussed in the final chapter. The appendices cover kinematic, cross-section and decay-rate formulae, Breit-Wigner resonances, some Clebsch-Gordan coefficient tables, a table of particle properties, exercises and answers, and the Dirac equation. There is also an appendix on calculating scattering amplitudes for fermion + fermion going to fermion + fermion. A list of references is given. (U.K.)
International Nuclear Information System (INIS)
Arakawa, Kazuo.
1969-01-01
An accelerator is disclosed having a device which permits the electrodes of an accelerator tube to be readily conditioned in an uncomplicated manner before commencing operation. In particle accelerators, it is necessary to condition the accelerator electrodes before a stable high voltage can be applied. Large current accelerators of the cockcroft-walton type require a complicated manual operation which entails applying to the electrodes a low voltage which is gradually increased to induce a vacuum discharge and then terminated. When the discharge attains an extremely low level, the voltage is again impressed and again raised to a high value in low current type accelerators, a high voltage power supply charges the electrodes once to induce discharge followed by reapplying the voltage when the vacuum discharge reaches a low level, according to which high voltage is automatically applied. This procedure, however, requires that the high voltage power supply be provided with a large internal resistance to limit the current to within several milliamps. The present invention connects a high voltage power supply and an accelerator tube through a discharge current limiting resistor wired in parallel with a switch. Initially, the switch is opened enabling the power supply to impress a voltage limited to a prescribed value by a suitably chosen resistor. Conditioning is effected by allowing the voltage between electrodes to increase and is followed by closing the switch through which high voltage is applied directly to the accelerator for operation. (K.J. Owens)
Katarina Anthony
2011-01-01
Could the principles of particle physics ever be explained by a game? Could a deck of cards ever teach the Standard Model the way Monopoly teaches economics? According to players of the Quark Matter card game, the answer is an easy “yes!”. Csaba Török and Judit Csörgő (second and third from left) at the award ceremony for the Eötvös University Innovation Contest. When he was only 17 years old, Hungarian student Csaba Török came up with the idea for the Quark Matter cards. “I wanted people to think of the Standard Model as fun – not just a serious, scientific theory,” says Csaba. “The cards can turn everyone into a pseudo-physicist.” He shared the idea with his friend Judit Csörgő and her physicist father, Tamás Csörgő, and together they went on to develop Quark Matter into the game it is today. Csaba and Judit were both members o...
Particle-accelerator decommissioning
International Nuclear Information System (INIS)
Opelka, J.H.; Mundis, R.L.; Marmer, G.J.; Peterson, J.M.; Siskind, B.; Kikta, M.J.
1979-12-01
Generic considerations involved in decommissioning particle accelerators are examined. There are presently several hundred accelerators operating in the United States that can produce material containing nonnegligible residual radioactivity. Residual radioactivity after final shutdown is generally short-lived induced activity and is localized in hot spots around the beam line. The decommissioning options addressed are mothballing, entombment, dismantlement with interim storage, and dismantlement with disposal. The recycle of components or entire accelerators following dismantlement is a definite possibility and has occurred in the past. Accelerator components can be recycled either immediately at accelerator shutdown or following a period of storage, depending on the nature of induced activation. Considerations of cost, radioactive waste, and radiological health are presented for four prototypic accelerators. Prototypes considered range from small accelerators having minimal amounts of radioactive mmaterial to a very large accelerator having massive components containing nonnegligible amounts of induced activation. Archival information on past decommissionings is presented, and recommendations concerning regulations and accelerator design that will aid in the decommissioning of an accelerator are given
EXHIBITION: Accelerated Particles
2004-01-01
An exhibition of plastic arts and two evenings of performances by sound and visual artists as part of CERN's 50th anniversary celebrations. Fifty candles for CERN, an international laboratory renowned for fundamental research, is a cause for celebration. Since March this year, Geneva and neighbouring parts of France have been the venues for a wealth of small and large-scale events, which will continue until November. Given CERN's location in the commune of Meyrin, the ForuMeyrin is hosting exhibitions of plastic arts and performances entitled: Accelerated Particles. Several works will be exhibited and performed in two 'salons'. Salon des matières: An exhibition of plastic arts From Tues 12 October to Wed 3 November 2004 Tuesdays to Fridays: 16:00 to 19:00 Saturdays: 14:00 to 18:00 Exhibition open late on performance nights, entrance free Salon des particules: Musical and visual performances Tues 12 and Mon 25 October from 20:00 to 23:00 Preview evening for both events: Tues 12 October from 18:...
EXHIBITION: Accelerated Particles
2004-01-01
http://www.cern.ch/cern50/ An exhibition of plastic arts and two evenings of performances by sound and visual artists as part of CERN's fiftieth anniversary celebrations. The fiftieth anniversary of a world famous organization like CERN, an international laboratory specializing in fundamental research, is a cause for celebration. Since March this year, Geneva and neighbouring parts of France have been the venues for a wealth of small and large-scale events, which will continue until November. Given CERN's location in the commune of Meyrin, the ForuMeyrin is hosting two "salons" consisting of an exhibition of plastic arts and evenings of music and visual arts performances with the collective title of "Accelerated Particles". Several works will be exhibited and performed. Salon des matières: An exhibition of plastic arts Until Wednesday 3 November 2004. Tuesdays to Fridays: 4.00 p.m. to 7.00 p.m. Saturdays: 2.00 p.m. to 6.00 p.m. Doors open late on the evening of the performances. Salon des ...
International Nuclear Information System (INIS)
Yao, Y.P.
1981-01-01
There are two problems discussed, both of which have to do with dissimilar magnitudes in mass. Theoretically, we can devise the large difference in mass as observed by decreeing some vev, v/sub i/ to be much bigger than the other; or, we can assume that some couplings g/sub i/ are much stronger. These two different assumptions give rise to entirely different patterns of interaction in the resulting theory. The first way to generate a mass hierarchy can be called the soft way, because in the zeroth order, the large mass scale leaves its foot print merely in a few effective parameters of the residual theory. The effective theory is renormalizable, sans anomaly. In this limit, the heavy particles decouple. The second assumption (g/sub j/ much greater than g/sub j'/) to create mass hierarchy does a lot of violence to a theory. Effects of the large mass scale will be felt by the system left behind in many ways. An infinite number of parameters are needed to summarize the effects in this limit. This is called the hard limit. It follows that the resulting effective Lagrangian, if in fact it makes sense to construct one at all, will be non-polynomial and apparently non-renormalizable
International Nuclear Information System (INIS)
Hofmann, A.; Messerschmid, E.; Lawson, J.D.
1976-01-01
These lectures present a survey of some of the concepts of plasma physics and look at some situations familiar to particle-accelerator physicists from the point of view of a plasma physicist, with the intention of helping to link together the two fields. At the outset, basic plasma concepts are presented, including definitions of a plasma, characteristic parameters, magnetic pressure and confinement. This is followed by a brief discussion on plasma kinetic theory, non-equilibrium plasma, and the temperature of moving plasmas. Examples deal with beams in the CERN Intersecting Storage Rings as well as with non-steady beams in cyclic accelerators and microwave tubes. In the final chapters, time-varying systems are considered: waves in free space and the effect of cylinder bounds, wave motion in cold stationary plasmas, and waves in plasmas with well-defined streams. The treatment throughout is informal, with emphasis on the essential physical properties of continuous beams in accelerators and storage rings in relation to the corresponding problems in plasma physics and microwave tubes. (Author)
PENTACLE: Parallelized particle-particle particle-tree code for planet formation
Iwasawa, Masaki; Oshino, Shoichi; Fujii, Michiko S.; Hori, Yasunori
2017-10-01
We have newly developed a parallelized particle-particle particle-tree code for planet formation, PENTACLE, which is a parallelized hybrid N-body integrator executed on a CPU-based (super)computer. PENTACLE uses a fourth-order Hermite algorithm to calculate gravitational interactions between particles within a cut-off radius and a Barnes-Hut tree method for gravity from particles beyond. It also implements an open-source library designed for full automatic parallelization of particle simulations, FDPS (Framework for Developing Particle Simulator), to parallelize a Barnes-Hut tree algorithm for a memory-distributed supercomputer. These allow us to handle 1-10 million particles in a high-resolution N-body simulation on CPU clusters for collisional dynamics, including physical collisions in a planetesimal disc. In this paper, we show the performance and the accuracy of PENTACLE in terms of \\tilde{R}_cut and a time-step Δt. It turns out that the accuracy of a hybrid N-body simulation is controlled through Δ t / \\tilde{R}_cut and Δ t / \\tilde{R}_cut ˜ 0.1 is necessary to simulate accurately the accretion process of a planet for ≥106 yr. For all those interested in large-scale particle simulations, PENTACLE, customized for planet formation, will be freely available from https://github.com/PENTACLE-Team/PENTACLE under the MIT licence.
ASME method for particle reconstruction
International Nuclear Information System (INIS)
Ierusalimov, A.P.
2009-01-01
The method of approximate solution of motion equation (ASME) was used to reconstruct the parameters for charged particles. It provides a good precision for momentum, angular and space parameters of particles in coordinate detectors. The application of the method for CBM, HADES and MPD/NICA setups is discussed
Blind Analysis in Particle Physics
International Nuclear Information System (INIS)
Roodman, A
2003-01-01
A review of the blind analysis technique, as used in particle physics measurements, is presented. The history of blind analyses in physics is briefly discussed. Next the dangers of and the advantages of a blind analysis are described. Three distinct kinds of blind analysis in particle physics are presented in detail. Finally, the BABAR collaboration's experience with the blind analysis technique is discussed
Particle sizes from sectional data
DEFF Research Database (Denmark)
Pawlas, Zbynek; Nyengaard, Jens Randel; Jensen, Eva Bjørn Vedel
2009-01-01
We propose a new statistical method for obtaining information about particle size distributions from sectional data without specific assumptions about particle shape. The method utilizes recent advances in local stereology. We show how to estimate separately from sectional data the variance due t...
Biron, Lauren
2016-01-01
For lovers of rhymes and anthropomorphic Higgs bosons, Symmetry presents its first published board book, The ABCs of Particle Physics. Use it as an illustrated guide to basic particle- and astrophysics terms, or read it to your infant at bedtime, if you don’t mind their first word being “quark.”
International Nuclear Information System (INIS)
Ferreira, P.L.; Palladino, B.E.
1985-01-01
The problem of a Dirac particle in stationary motion on S 2 - a two dimensional sphere embedded in Euclidean space E 3 - is discussed. It provides a particularly simple case of an exactly solvable constrained Dirac particle whose properties are here studied, with emphasis on its magnetic moment. (Author) [pt
Relativistic particle in a box
Alberto, P.; Fiolhais, Carlos; Gil, Victor
1996-01-01
The problem of a relativistic spin 1/2 particle confined to a one-dimensional box is solved in a way that resembles closely the solution of the well known quantum-mechanical textbook problem of a non-relativistic particle in a box. The energy levels and probability density are computed and compared with the non-relativistic case
Lagrangian multi-particle statistics
DEFF Research Database (Denmark)
Lüthi, Beat; Berg, Jacob; Ott, Søren
2007-01-01
Combined measurements of the Lagrangian evolution of particle constellations and the coarse-grained velocity derivative tensor. partial derivative(u) over tilde (i) /partial derivative x(j) are presented. The data are obtained from three-dimensional particle tracking measurements in a quasi isotr...
Largest particle detector nearing completion
2006-01-01
"Construction of another part of the Large Hadron Collider (LHC), the worl's largest particle accelerator at CERN in Switzerland, is nearing completion. The Compact Muon Solenoid (CMS) is oner of the LHC project's four large particle detectors. (1/2 page)
TEACHING PHYSICS: Teaching particle physics
Hanley, Phil
2000-09-01
Particle physics attracts many students who hear of news from CERN or elsewhere in the media. This article examines which current A-level syllabuses include which bits of particle physics and surveys the many different types of resource available to teachers and students.
Nanodiamond particles forming photonic structures
International Nuclear Information System (INIS)
Grichko, Varvara; Tyler, Talmage; Grishko, Victor I; Shenderova, Olga
2008-01-01
Colloid suspensions of irregularly shaped, highly charged detonation nanodiamond particles are found to have unexpected optical properties, similar to those of photonic crystals. This finding is all the more surprising since the particles used in this work are far more polydisperse than those typically forming photonic crystals. Intensely iridescent structures have been fabricated using the centrifugation of aqueous suspensions of nanodiamonds
Nanodiamond particles forming photonic structures
Energy Technology Data Exchange (ETDEWEB)
Grichko, Varvara; Tyler, Talmage; Grishko, Victor I; Shenderova, Olga [International Technology Center, 8100 Brownleigh Drive, Suite 120, Raleigh, NC 27617 (United States)], E-mail: oshenderova@itc-inc.org
2008-06-04
Colloid suspensions of irregularly shaped, highly charged detonation nanodiamond particles are found to have unexpected optical properties, similar to those of photonic crystals. This finding is all the more surprising since the particles used in this work are far more polydisperse than those typically forming photonic crystals. Intensely iridescent structures have been fabricated using the centrifugation of aqueous suspensions of nanodiamonds.
Widick, Paul R.
1969-01-01
Described are activities that are designed to help elementary children understand the possibility of the particle theory of matter. Children work with beads, marbles, B-B shot and sand; by mixing these materials and others they are led to see that it is highly possible for the existence of particles which are not visible. (BR)
Precipitation scavenging of aerosol particles
International Nuclear Information System (INIS)
Radke, L.F.; Eltgroth, M.W.; Hobbs, P.V.
1978-01-01
The paper presents the results of precipitation scavenging measurements of particles in the atmosphere and in plumes which were obtained using an airborne measuring system. Attention is given to the so-called 'Greenfield gap' and collection efficiencies for submicron particles
Viscosity of particle laden films
Timounay, Yousra; Rouyer, Florence
2017-06-01
We perform retraction experiments on soap films where large particles bridge the two interfaces. Local velocities are measured by PIV during the unstationnary regime. The velocity variation in time and space can be described by a continuous fluid model from which effective viscosity (shear and dilatational) of particulate films is measured. The 2D effective viscosity of particulate films η2D increases with particle surface fraction ϕ: at low ϕ, it tends to the interfacial dilatational viscosity of the liquid/air interfaces and it diverges at the critical particle surface fraction ϕc ≃ 0.84. Experimental data agree with classical viscosity laws of hard spheres suspensions adapted to the 2D geometry, assuming viscous dissipation resulting from the squeeze of the liquid/air interfaces between the particles. Finally, we show that the observed viscous dissipation in particulate films has to be considered to describe the edge velocity during a retraction experiment at large particle coverage.
What's Next for Particle Physics?
White, Martin
2017-10-01
Following the discovery of the Higgs boson in 2012, particle physics has entered its most exciting and crucial period for over 50 years. In this book, I first summarise our current understanding of particle physics, and why this knowledge is almost certainly incomplete. We will then see that the Large Hadron Collider provides the means to search for the next theory of particle physics by performing precise measurements of the Higgs boson, and by looking directly for particles that can solve current cosmic mysteries such as the nature of dark matter. Finally, I will anticipate the next decade of particle physics by placing the Large Hadron Collider within the wider context of other experiments. The results expected over the next ten years promise to transform our understanding of what the Universe is made of and how it came to be.
Particle creation during vacuum decay
International Nuclear Information System (INIS)
Rubakov, V.A.
1984-01-01
The hamiltonian approach is developed with regard to the problem of particle creation during the tunneling process, leading to the decay of the false vacuum in quantum field theory. It is shown that, to the lowest order in (h/2π), the particle creation is described by the euclidean Schroedinger equation in an external field of a bounce. A technique for solving this equation is developed in an analogy to the Bogoliubov transformation technique, in the theory of particle creation in the presence of classical background fields. The technique is illustrated by two examples, namely, the particle creation during homogeneous vacuum decay and during the tunneling process leading to the materialization of the thin-wall bubble of a new vacuum in the metastable one. The curious phenomenon of intensive particle annihilation during vacuum decay is discussed and explicitly illustrated within the former example. The non-unitary extension of the Bogoliubov u, v transformations is described in the appendix. (orig.)
Selective encapsulation by Janus particles
Energy Technology Data Exchange (ETDEWEB)
Li, Wei, E-mail: wel208@mrl.ucsb.edu [Materials Research Laboratory, University of California, Santa Barbara, California 93106 (United States); Ruth, Donovan; Gunton, James D. [Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015 (United States); Rickman, Jeffrey M. [Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015 (United States); Department of Materials Science and Engineering, Lehigh University, Bethlehem, Pennsylvania 18015 (United States)
2015-06-28
We employ Monte Carlo simulation to examine encapsulation in a system comprising Janus oblate spheroids and isotropic spheres. More specifically, the impact of variations in temperature, particle size, inter-particle interaction range, and strength is examined for a system in which the spheroids act as the encapsulating agents and the spheres as the encapsulated guests. In this picture, particle interactions are described by a quasi-square-well patch model. This study highlights the environmental adaptation and selectivity of the encapsulation system to changes in temperature and guest particle size, respectively. Moreover, we identify an important range in parameter space where encapsulation is favored, as summarized by an encapsulation map. Finally, we discuss the generalization of our results to systems having a wide range of particle geometries.
Health effects of exhaust particles
Energy Technology Data Exchange (ETDEWEB)
Pihlava, T.; Uuppo, M.; Niemi, S.
2013-11-01
This report introduces general information about diesel particles and their health effects. The purpose of this report is to introduce particulate matter pollution and present some recent studies made regarding the health effects of particulate matter. The aim is not to go very deeply into the science, but instead to keep the text understandable for the average layman. Particulate matter is a complex mixture of extremely small particles and liquid droplets. These small particles are made up of a number of components that include for example acids, such as nitrates and sulphates, as well as organic chemicals, metals and dust particles from the soil. Particulate matter comes from several sources, such as transportation emissions, industrial emissions, forest fires, cigarette smoke, volcanic ash and climate variations. Particles are divided into coarse particles with diameters less than 10 ..m, fine particles with diameters smaller than 2.5 ..m and ultra-fine particles with diameters less than 0.1 ..m. The particulate matter in diesel exhaust gas is a highly complex mixture of organic, inorganic, solid, volatile and partly volatile compounds. Many of these particles do not form until they reach the air. Many carcinogenic compounds have been found in diesel exhaust gas and it is considered carcinogenic to humans. Particulate matter can cause several health effects, such as premature death in persons with heart or lung disease, cancer, nonfatal heart attacks, irregular heartbeat, aggravated asthma, decreased lung function and an increase in respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing. It is estimated that in Finland about 1300 people die prematurely due to particles and the economic loss in the EU due to the health effects of particles can be calculated in the billions. Ultra-fine particles are considered to be the most harmful to human health. Ultrafine particles usually make the most of their quantity and surface area
Separating particles from a liquid
International Nuclear Information System (INIS)
Leslie, C.M.; Watson, J.H.P.; Williams, J.A.
1980-01-01
An apparatus for separating particles suspended in a liquid from the liquid, is described, in which a flow of the liquid is passed through a filter bed of ferromagnetic bodies which acts as a coarse filter to trap the larger particles in the flow. The filter bed is arranged within a truncated core between the poles of an electromagnet. To cleanse the bed and flush out the trapped particles a wash liquid is passed through the bed and the electromagnet is energised to levitate the bed to allow the wash liquid to remove the particles. The liquid flow from the coarse filter can be passed to a high gradient magnetic separator at which remaining small particles in the flow are filtered magnetically. (U.K.)
Method to detect biological particles
International Nuclear Information System (INIS)
Giaever, I.
1976-01-01
A medical-diagnostic method to detect immunological as well as other specific reactions is described. According to the invention, first reactive particles (e.g. antibodies) are adsorbed on the surface of a solid, non-reactive substrate. The coated substrate is subjected to a solution which one assumes to contain the second biological particles (e.g. antigens) which are specific to the first and form complexes with these. A preferential radioactive labelling (e.g. with iodine 125) of the second biological particle is then directly or indirectly carried out. Clearage follows labelling in order to separate the second biological particles from the first ones. A specific splitting agent can selectively break the bond of both types of particle. The splitting agent solution is finally separated off and its content is investigated for the presence of labelling. (VJ) [de
Turbulent diffusion of small particles
International Nuclear Information System (INIS)
Margolin, L.G.
1977-11-01
The diffusion of small, spherical, rigid particles suspended in an incompressible turbulent fluid, but not interacting with each other, was studied. As a stochastic process, the turbulent fluid velocity field is assumed to be homogeneous, isotropic and stationary. Assuming the Stokes regime, a particle of equation of motion is used which includes only the effects of Stokes drag and a virtual mass force and an exact solution is found for the particle velocity correlation function, for all times and initial conditions, in terms of a fluid velocity correlation function measured along the motion of the particle. This shows that for times larger than a certain time scale, the particle velocity correlation becomes stationary. The effect of small shears in the fluid velocity was considered, under the additional restrictions of a certain high frequency regime for the turbulence. The shears convected past the particle much faster than the growth of the boundary layer. New force terms due to the presence of such shears are calculated and incorporated into the equation of motion. A perturbation solution to this equation is constructed, and the resultant particle velocity correlation function and diffusion coefficient are calculated. To lowest order, the particle diffusivity is found to be unaltered by the presence of small mean flow shears. The last model treated is one in which particles traverse a turbulent fluid with a large mean velocity. Among other restrictions, linearized form drag is assumed. The diffusion coefficient for such particles was calculated, and found to be much smaller than the passive scalar diffusion coefficient. This agrees within 5 percent with the experimental results of Snyder and Lumley
International Nuclear Information System (INIS)
Ido, Y; Yamaguchi, T; Inagaki, T
2009-01-01
Microstructure formation of magnetic particles and nonmagnetic particles in MR fluids is investigated using the particle method simulation. Nonmagnetic sphere particles are rearranged in the field direction due to the chain-like cluster formation of magnetic particles. In the contrast, the nonmagnetic spherocylinder particles are not sufficiently rearranged in the field direction by using the cluster formation of sphere magnetic particles.
International Nuclear Information System (INIS)
Mansouri, F.; Suranyi, P.; Wijewardhana, L.C.R.
1992-10-01
Dynamics of 2+1 dimensional gravity is analyzed by coupling matter to Chern Simons Witten action in two ways and obtaining the exact gravity Hamiltonian for each case. 't Hoot's Hamiltonian is obtained as an approximation. The notion of space-time emerges in the very end as a broken phase of the gauge theory. We have studied the patterns of discrete and continuous symmetry breaking in 2+1 dimensional field theories. We formulate our analysis in terms of effective composite scalar field theories. Point-like sources in the Chern-Simons theory of gravity in 2+1 dimensions are described by their Poincare' charges. We have obtained exact solutions of the constraints of Chern-Simons theory with an arbitrary number of isolated point sources in relative motion. We then showed how the space-time metric is constructed. A reorganized perturbation expansion with a propagator of soft infrared behavior has been used to study the critical behavior of the mass gap. The condition of relativistic covariance fixes the form of the soft propagator. Approximants to the correlation critical exponent were obtained in two loop order for the two and three dimensional theories. We proposed a new model of QED exhibiting two phases and a Majorana mass spectrum of single particle states. The model has a new source of coupling constant renormalization which opposes screening and suggests the model may confine. Assuming that the bound states of e + e - essentially obey a Majorana spectrum, we obtained a consistent fit of the GSI peaks as well as predicting new peaks and their spin assignments
Heavy charged particle therapy
International Nuclear Information System (INIS)
Mizoe, Jun-etsu
1995-01-01
A pilot study of heavy charged particles with heavy ion medical accelerator in Chiba (HIMAC) for advanced H and N cancer has been carried out from June 1994 at National Institute of Radiological Sciences (NIRS). As of the beginning of August 1994, three patients were treated by 290 MeV carbon ions. The patients had adenocarcinoma of the cheek mucosa, squamous cell carcinoma of the ethmoid sinus and adenoid cystic carcinoma of the sublingual gland. Patients were immobilized by individual head coach and thermosplint facial shell. Individual collimators and bolus were also prepared for each ports. Dose fractionation for the initial pilot study group was 16.2 GyE/18 fractions/6 weeks, which would be equivalent to standard fractionation of 60.0 Gy/30 fractions/6 weeks with photons. This dose fractionation was considered to be 20% lesser than 75 GyE/37.5 fractions/7.5 weeks, which is estimated to be maximum tolerance dose for advanced H and N cancers. HIMAC worked well and there was no major trouble causing any treatment delay. Acute skin reactions of 3 patients were 2 cases of bright erythema with patchy moist desquamation and one of dull erythema, which were evaluated as equivalent reaction with irradiated dose. Acute mucosa reactions appeared to have lesser reaction than predicted mucositis. Tumor reactions of three patients were partial reaction (PR) at the end of treatment and nearly complete remission (CR) after 6 months of treatment. From October 1994, we started to treat patients with advanced H and N cancer with 10% high dose than previous dose. And new candidates of pilot study with non small cell lung cancer, brain tumor and carcinoma of the tongue were entered into pilot study. At the end of February 1995, a total of 21 patients were treated by carbon ions. (J.P.N.)
Negative numbers and antimatter particles
International Nuclear Information System (INIS)
Tsan, Ung Chan
2012-01-01
Dirac's equation states that an electron implies the existence of an antielectron with the same mass (more generally same arithmetic properties) and opposite charge (more generally opposite algebraic properties). Subsequent observation of antielectron validated this concept. This statement can be extended to all matter particles; observation of antiproton, antineutron, antideuton … is in complete agreement with this view. Recently antihypertriton was observed and 38 atoms of antihydrogen were trapped. This opens the path for use in precise testing of nature's fundamental symmetries. The symmetric properties of a matter particle and its mirror antimatter particle seem to be well established. Interactions operate on matter particles and antimatter particles as well. Conservation of matter parallels addition operating on positive and negative numbers. Without antimatter particles, interactions of the Standard Model (electromagnetism, strong interaction and weak interaction) cannot have the structure of group. Antimatter particles are characterized by negative baryonic number A or/and negative leptonic number L. Materialization and annihilation obey conservation of A and L (associated to all known interactions), explaining why from pure energy (A = 0, L = 0) one can only obtain a pair of matter particle antimatter particle — electron antielectron, proton and antiproton — via materialization where the mass of a pair of particle antiparticle gives back to pure energy with annihilation. These two mechanisms cannot change the difference in the number of matter particles and antimatter particles. Thus from pure energy only a perfectly symmetric (in number) universe could be generated as proposed by Dirac but observation showed that our universe is not symmetric, it is a matter universe which is nevertheless neutral. Fall of reflection symmetries shattered the prejudice that there is no way to define in an absolute way right and left or matter and antimatter
Laser and Particle Guiding Micro-Elements for Particle Accelerators
Plettner, Tomas; Spencer, James; Wisdom, Jeffrey
2005-01-01
Laser driven particle accelerators based on the current generation of lasers will require sub-micron control of the laser field as well as precise beam guiding. Hence the fabrication techniques that allow integrating both elements into an accelerator-on-chip format become critical for the success of such particle accelerators. Micromachining technology for silicon has been shown to be one such feasible technology in PAC2003 but with a variety of complications on the laser side. Fortunately, in recent years the fabrication of transparent ceramics has become an interesting technology that could be applied for laser-particle accelerators in several ways. We discuss this area, its advantages such as the range of materials it provides and various ways to implement it followed by some different test examples that have been considered. One important goal of this approach is an integrated system that could avoid the necessity of having to inject either laser or particle pulses into these structures.
Particle-wall tribology of slippery hydrogel particle suspensions.
Shewan, Heather M; Stokes, Jason R; Cloitre, Michel
2017-03-08
Slip is an important phenomenon that occurs during the flow of yield stress fluids like soft materials and pastes. Densely packed suspensions of hydrogel microparticles are used to show that slip is governed by the tribological interactions occurring between the samples and shearing surfaces. Both attractive/repulsive interactions between the dispersed particles and surface, as well as the viscoelasticity of the suspension, are found to play key roles in slip occurring within rheometric flows. We specifically discover that for two completely different sets of microgels, the sliding stress at which slip occurs scales with both the modulus of the particles and the bulk suspension modulus. This suggests that hysteresis losses within the viscoelastic particles contribute to friction forces and thus slip at the particle-surface tribo-contact. It is also found that slip during large amplitude oscillatory shear and steady shear flows share the same generic features.
Particles matter: Transformation of suspended particles in constructed wetlands
Mulling, B.T.M.
2013-01-01
This thesis shows that constructed wetlands transform suspended particles in (treated) municipal wastewater through selective precipitation in ponds, biological filtering by plankton communities and physical and biological retention in reed beds. These processes effectively remove faecal indicator
Structures in elementary particles. An electromagnetic elementary-particle model
International Nuclear Information System (INIS)
Meyer, Carl-Friedrich
2015-01-01
A picture of matter is developed, which is suited to develope and to explain the experimentally determined properties of the elementary particles and the basing structures starting from few known physical conditions in a simple and understandable way. It explains illustratively the spin and the structure of the stable particles, symmetry properties resulting from the half-integerness of the spin, the nature of the electric charge and the third-integerness of the charges in hadrons resulting from this, the stability and the indivisibility f the proton, the conditions for the formation and stability of the particles, and the causes for the limited lifetime of unstable particles like the free neutron. It opens also the view on the cause for the quantization of all for us known processes in the range of the microcosm and creates so an illustrative picture of the matter surrounding us.
Energy Technology Data Exchange (ETDEWEB)
Bodmer, A.R. [Illinois Univ., Chicago, IL (United States). Dept. of Physics]|[Argonne National Lab., IL (United States); Usmani, Q.N.; Sami, M. [Jamia Millia Islamia, New Delhi (India). Dept. of Physics
1993-09-01
We consider the binding energies of {Lambda} hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A {le} 89 and for orbital angular momenta {ell}{sub {Lambda}} {le} 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei {sub {Lambda}}{sup A}Z with baryon number A in which a single {Lambda} hyperon (baryon number = 1) is bound to an ordinary nucleus {sup A}Z consisting of A - 1 nucleons = Z protons + N neutrons. The {Lambda} hyperon is neutral, has spin 1/2, strangeness S = {minus}1, isospin I = O and a mass M{sub {Lambda}} = 1116 MeV/c{sup 2}. Although the {Lambda} interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V{sub {Lambda}N} {approx} 0.5 V{sub NN}. As a result, the two-body {Lambda}N system is unbound, and the lightest bound HN is the three-body hypertriton {sub {Lambda}}{sup 3}H in which the {Lambda} is bound to a deuteron with the {Lambda}-d separation energy being only {approx} 0.1 MeV corresponding to an exponential tail of radius {approx} 15 fm! In strong interactions the strangeness S is of course conserved, and the {Lambda} is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the {Lambda} which can decay either via ``free`` pionic decay {Lambda} {yields} N + {pi} or via induced decay {Lambda} + N {yields} N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime {approx} 10{sup {minus}10}s is in fact close to the lifetime of a free {Lambda}. Since this is much longer than the strong interaction time {approx} 10{sup {minus}22}s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei.
International Nuclear Information System (INIS)
Bodmer, A.R.; Usmani, Q.N.; Sami, M.
1993-01-01
We consider the binding energies of Λ hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A ≤ 89 and for orbital angular momenta ell Λ ≤ 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei Λ A Z with baryon number A in which a single Λ hyperon (baryon number = 1) is bound to an ordinary nucleus A Z consisting of A - 1 nucleons = Z protons + N neutrons. The Λ hyperon is neutral, has spin 1/2, strangeness S = -1, isospin I = O and a mass M Λ = 1116 MeV/c 2 . Although the Λ interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V ΛN ∼ 0.5 V NN . As a result, the two-body ΛN system is unbound, and the lightest bound HN is the three-body hypertriton Λ 3 H in which the Λ is bound to a deuteron with the Λ-d separation energy being only ∼ 0.1 MeV corresponding to an exponential tail of radius ∼ 15 fm exclamation point In strong interactions the strangeness S is of course conserved, and the Λ is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the Λ which can decay either via ''free'' pionic decay Λ → N + π or via induced decay Λ + N → N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime ∼ 10 -10 s is in fact close to the lifetime of a free Λ. Since this is much longer than the strong interaction time ∼ 10 -22 s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei
Suspending Zeolite Particles In Tanks
International Nuclear Information System (INIS)
Poirier, M.R.
1999-01-01
The Savannah River Site (SRS) is in the process of removing waste (sludge and salt cake) from million gallon waste tanks. The current practice for removing waste from the tanks is adding water, agitating the tanks with long shaft vertical centrifugal pumps, and pumping the sludge/salt solution from the tank to downstream treatment processes. This practice has left sludge heels (tilde 30,000 gallons) in the bottom of the tanks. SRS is evaluating shrouded axial impeller mixers for removing the sludge heels in the waste tanks. The authors conducted a test program to determine mixer requirements for suspending sludge heels using the shrouded axial impeller mixers. The tests were performed with zeolite in scaled tanks which have diameters of 1.5, 6.0, and 18.75 feet. The mixer speeds required to suspend zeolite particles were measured at each scale. The data were analyzed with various scaling methods to compare their ability to describe the suspension of insoluble solids with the mixers and to apply the data to a full-scale waste tank. The impact of changes in particle properties and operating parameters was also evaluated. The conclusions of the work are: Scaling of the suspension of fast settling zeolite particles was best described by the constant power per unit volume method. Increasing the zeolite particle concentration increased the required mixer power needed to suspend the particles. Decreasing the zeolite particle size from 0.7 mm 0.3 mm decreased the required mixer power needed to suspend the particles. Increasing the number of mixers in the tank decreased the required mixer power needed to suspend the particles. A velocity of 1.6 ft/sec two inches above the tank bottom is needed to suspend zeolite particles
Introduction to Particle Physics course
CERN. Geneva HR-RFA
2006-01-01
These lectures are an introduction to the ideas of particle physics, aimed at students and teachers with little or on knowledge of the subject. They form a broad basis that will be developed in more detail by the subsequent lecturers in the school. These four lectures are meant to present an overview of particle physics based on its historical evolution over the past century. It will be shown how concepts have evolved following progress in instrumentation and in theoretical ideas, from atoms to the elementary particles and their interactions, as they are known today.
Superconducting Magnets for Particle Accelerators
Bottura, Luca; Yamamoto, Akira; Zlobin, Alexander V
2016-01-01
In this paper we summarize the evolution and contributions of superconducting magnets to particle accelerators as chronicled over the last 50 years of Particle Accelerator Conferences (PAC, NA-PAC and IPAC). We begin with an historical overview based primarily on PAC Proceedings augmented with references to key milestones in the development of superconducting magnets for particle accelerators. We then provide some illustrative examples of applications that have occurred over the past 50 years, focusing on those that have either been realized in practice or provided technical development for other projects, with discussion of possible future applications.
Particle diffusion in a spheromak
International Nuclear Information System (INIS)
Meyerhofer, D.D.; Levinton, F.M.; Yamada, M.
1988-01-01
The local carbon particle diffusion coefficient was measured in the Proto S-1/C spheromak using a test particle injection scheme. When the plasma was not in a force-free Taylor state, and when there were pressure gradients in the plasma, the particle diffusion was five times that predicted by Bohm and was consistent with collisional drift wave diffusion. The diffusion appears to be driven by correlations of the fluctuating electric field and density. During the decay phase of the discharge when the plasma was in the Taylor state, the diffusion coefficient of the carbon was classical. 23 refs., 4 figs
International Nuclear Information System (INIS)
Bewerunge, Jörg; Capellmann, Ronja F.; Platten, Florian; Egelhaaf, Stefan U.; Sengupta, Ankush; Sengupta, Surajit
2016-01-01
Colloidal particles were exposed to a random potential energy landscape that has been created optically via a speckle pattern. The mean particle density as well as the potential roughness, i.e., the disorder strength, were varied. The local probability density of the particles as well as its main characteristics were determined. For the first time, the disorder-averaged pair density correlation function g (1) (r) and an analogue of the Edwards-Anderson order parameter g (2) (r), which quantifies the correlation of the mean local density among disorder realisations, were measured experimentally and shown to be consistent with replica liquid state theory results.
SPS experiments with light particles
Tenner, A G
1977-01-01
High energy physics during the last 20 years has utilized proton accelerators like the CERN PS. Now, however, fundamental questions can only be answered through experiments using beams of electrons, muons or neutrinos for the study of collisions between light particles or between light and heavy particles. The detection of light particles as the end products of interactions is also of great interest. The super protosynchrotron experimental programme which started in January 1977 is discussed with particular reference to the Big European Bubble Chamber (BEBC). (2 refs).
Fractals control in particle's velocity
International Nuclear Information System (INIS)
Zhang Yongping; Liu Shutang; Shen Shulan
2009-01-01
Julia set, a fractal set of the literature of nonlinear physics, has significance for the engineering applications. For example, the fractal structure characteristics of the generalized M-J set could visually reflect the change rule of particle's velocity. According to the real world requirement, the system need show various particle's velocity in some cases. Thus, the control of the nonlinear behavior, i.e., Julia set, has attracted broad attention. In this work, an auxiliary feedback control is introduced to effectively control the Julia set that visually reflects the change rule of particle's velocity. It satisfies the performance requirement of the real world problems.
Simulations of flame generated particles
Patterson, Robert
2016-01-05
The nonlinear structure of the equations describing the evolution of a population of coagulating particles in a flame make the use of stochastic particle methods attractive for numerical purposes. I will present an analysis of the stochastic fluctuations inherent in these numerical methods leading to an efficient sampling technique for steady-state problems. I will also give some examples where stochastic particle methods have been used to explore the effect of uncertain parameters in soot formation models. In conclusion I will try to indicate some of the issues in optimising these methods for the study of uncertain model parameters.
Ultrafine particles in the atmosphere
Brown, L M; Harrison, R M; Maynard, A D; Maynard, R L
2003-01-01
Following the recognition that airborne particulate matter, even at quite modest concentrations, has an adverse effect on human health, there has been an intense research effort to understand the mechanisms and quantify the effects. One feature that has shone through is the important role of ultrafine particles as a contributor to the adverse effects of airborne particles. In this volume, many of the most distinguished researchers in the field provide a state-of-the-art overview of the scientific and medical research on ultrafine particles. Contents: Measurements of Number, Mass and Size Distr
Electron microscopy of atmospheric particles
Huang, Po-Fu
Electron microscopy coupled with energy dispersive spectrometry (EM/EDS) is a powerful tool for single particle analysis. However, the accuracy with which atmospheric particle compositions can be quantitatively determined by EDS is often hampered by substrate-particle interactions, volatilization losses in the low pressure microscope chamber, electron beam irradiation and use of inaccurate quantitation factors. A pseudo-analytical solution was derived to calculate the temperature rise due to the dissipation of the electron energy on a particle-substrate system. Evaporative mass loss for a spherical cap-shaped sulfuric acid particle resting on a thin film supported by a TEM grid during electron beam impingement has been studied. Measured volatilization rates were found to be in very good agreement with theoretical predictions. The method proposed can also be used to estimate the vapor pressure of a species by measuring the decay of X-ray intensities. Several types of substrates were studied. We found that silver-coated silicon monoxide substrates give carbon detection limits comparable to commercially available substrates. An advantage of these substrates is that the high thermal conductivity of the silver reduces heating due to electron beam impingement. In addition, exposure of sulfuric acid samples to ammonia overnight substantially reduces sulfur loss in the electron beam. Use of size-dependent k-factors determined from particles of known compositions shows promise for improving the accuracy of atmospheric particle compositions measured by EM/EDS. Knowledge accumulated during the course of this thesis has been used to analyze atmospheric particles (Minneapolis, MN) selected by the TDMA and collected by an aerodynamic focusing impactor. 'Less' hygroscopic particles, which do not grow to any measurable extent when humidified to ~90% relative humidity, included chain agglomerates, spheres, flakes, and irregular shapes. Carbon was the predominant element detected in
Simulations of flame generated particles
Patterson, Robert
2016-01-01
The nonlinear structure of the equations describing the evolution of a population of coagulating particles in a flame make the use of stochastic particle methods attractive for numerical purposes. I will present an analysis of the stochastic fluctuations inherent in these numerical methods leading to an efficient sampling technique for steady-state problems. I will also give some examples where stochastic particle methods have been used to explore the effect of uncertain parameters in soot formation models. In conclusion I will try to indicate some of the issues in optimising these methods for the study of uncertain model parameters.
Hard sell for particle physics?
International Nuclear Information System (INIS)
Brown, Julian.
1994-01-01
With particle physics experimental research becoming ever more expensive, the author considers whether the cost of such research is worthwhile. As costs escalated on the Superconducting Supercollider, the project has now been terminated. Particle physicists must now look for commercial imperatives to justify their work. Many of the important spin-offs from particle physics research are described in order to justify the subject's continued funding, albeit at very high levels, where funds might otherwise be directed to more mundane but very necessary causes such as health care or education. (UK)
Detecting hidden particles with MATHUSLA
Evans, Jared A.
2018-03-01
A hidden sector containing light long-lived particles provides a well-motivated place to find new physics. The recently proposed MATHUSLA experiment has the potential to be extremely sensitive to light particles originating from rare meson decays in the very long lifetime region. In this work, we illustrate this strength with the specific example of a light scalar mixed with the standard model-like Higgs boson, a model where MATHUSLA can further probe unexplored parameter space from exotic Higgs decays. Design augmentations should be considered in order to maximize the ability of MATHUSLA to discover very light hidden sector particles.
Spectroscopy after the new particles
International Nuclear Information System (INIS)
Lipkin, H.J.
1975-06-01
Conventional spectroscopy was reexamined, and the puzzles and paradoxes which have arisen in attempting to describe the properties of the known particles are sought. It is noted that these may offer clues to the missing elements necessary for the description of the new particles. The minimum number of elementary building blocks, charm and color, the colored quark model for saturation, spin splittings in the meson spectrum, three kinds of quarks, the Melosh transformation and the Jackson frame, the Zweig rule mystery, new particles and old symmetries, f--A2 interference, and nonleptonic decay. (U.S.)
The discovery of subatomic particles
International Nuclear Information System (INIS)
Weinberg, S.
1984-01-01
This book developed from a course for students with no prior training in mathematics of physics to learn about the achievements of 20th century physics and classical physics. It covers the discovery of fundamental particles of ordinary atoms: the electron, the proton, and the neutron. The general outline is historical and it is for readers unfamiliar with classical physics who wish to understand the ideas and experiments that make up the history of 20th century physics. Contents include: A world of particles, the discovery of the electron, the atomic scale, the nucleus, more particles
Biomedical applications of magnetic particles
Mefford, Thompson
2018-01-01
Magnetic particles are increasingly being used in a wide variety of biomedical applications. Written by a team of internationally respected experts, this book provides an up-to-date authoritative reference for scientists and engineers. The first section presents the fundamentals of the field by explaining the theory of magnetism, describing techniques to synthesize magnetic particles, and detailing methods to characterize magnetic particles. The second section describes biomedical applications, including chemical sensors and cellular actuators, and diagnostic applications such as drug delivery, hyperthermia cancer treatment, and magnetic resonance imaging contrast.
Notes on elementary particle physics
Muirhead, William Hugh
1972-01-01
Notes of Elementary Particle Physics is a seven-chapter text that conveys the ideas on the state of elementary particle physics. This book emerged from an introductory course of 30 lectures on the subject given to first-year graduate students at the University of Liverpool. The opening chapter deals with pertinent terminologies in elementary particle physics. The succeeding three chapters cover the concepts of transition amplitudes, probabilities, relativistic wave equations and fields, and the interaction amplitude. The discussion then shifts to tests of electromagnetic interactions, particul
Particle displacement tracking for PIV
Wernet, Mark P.
1990-01-01
A new Particle Imaging Velocimetry (PIV) data acquisition and analysis system, which is an order of magnitude faster than any previously proposed system has been constructed and tested. The new Particle Displacement Tracing (PDT) system is an all electronic technique employing a video camera and a large memory buffer frame-grabber board. Using a simple encoding scheme, a time sequence of single exposure images are time coded into a single image and then processed to track particle displacements and determine velocity vectors. Application of the PDT technique to a counter-rotating vortex flow produced over 1100 velocity vectors in 110 seconds when processed on an 80386 PC.
Cosmological Reflection of Particle Symmetry
Directory of Open Access Journals (Sweden)
Maxim Khlopov
2016-08-01
Full Text Available The standard model involves particle symmetry and the mechanism of its breaking. Modern cosmology is based on inflationary models with baryosynthesis and dark matter/energy, which involves physics beyond the standard model. Studies of the physical basis of modern cosmology combine direct searches for new physics at accelerators with its indirect non-accelerator probes, in which cosmological consequences of particle models play an important role. The cosmological reflection of particle symmetry and the mechanisms of its breaking are the subject of the present review.
Dimensional considerations about elementary particles
International Nuclear Information System (INIS)
Cocconi, G.
1978-01-01
The search for fundamental elementary particles responsible for the observed behaviour of matter during the past decades is briefly reviewed, and the possibility is considered that the four fundamental interactions that shape things merge into a unique field when matter is so compressed that particles are at extremely small distances from one another. These interactions are the gravitational interaction, the electromagnetic interaction, the strong interaction, and the weak interaction. It is thought that a simple geometrical criterion, termed the 'elementary criterion', would suffice to indicate how the various interactions should behave as particles are brought closer to one another and thus approach the situation where all interactions merge. (6 references). (U.K.)
Superparamagnetic relaxation of weakly interacting particles
DEFF Research Database (Denmark)
Mørup, Steen; Tronc, Elisabeth
1994-01-01
The influence of particle interactions on the superparamagnetic relaxation time has been studied by Mossbauer spectroscopy in samples of maghemite (gamma-Fe2O3) particles with different particle sizes and particle separations. It is found that the relaxation time decreases with decreasing particl...
behaved particle swarm optimization (QPSO)
African Journals Online (AJOL)
Administrator
2011-06-13
Jun 13, 2011 ... experiment results of L-glutamic acid fermentation process showed that our ... Key words: Soft-sensing model, quantum-behaved particle swarm optimization ... information about such biochemical variables is, in most practical ...
Delivery of single accelerated particles
International Nuclear Information System (INIS)
McNulty, P.J.; Pease, V.P.; Bond, V.P.; Schimmerling, W.; Vosburgh, K.G.; Crebbin, K.; Everette, W.; Howard, J.
1978-01-01
It is desirable for certain experiments involving accelerators to have the capability of delivering just a single beam particle to the target area. The essential features of such a one-at-a-time facility are discussed. Two such facilities are described which were implemented at high-energy heavy ion accelerators without having to make major structural changes in the existing beam lines or substantially interfering with other accelerator uses. Two accelerator facilities are described which had the capability of delivering a single beam particle to the target area. This feature is necessary in certain experiments investigating visual phenomena induced by charged particles, other single particle interactions in biology, and other experiments in which the low intensities of cosmic rays need to be simulated. Both facilities were implemented without having to make structural changes in the existing beam lines or substantially interfering with other accelerator uses. (Auth.)
Duke Forest Particle Nucleation Data
U.S. Environmental Protection Agency — Particle size distribution expressed as number concentration per size bin. This dataset is associated with the following publications: Pillai, P., V. Aneja, J....
Particles trajectories in magnetic filaments
International Nuclear Information System (INIS)
Bret, A.
2015-01-01
The motion of a particle in a spatially harmonic magnetic field is a basic problem involved, for example, in the mechanism of formation of a collisionless shock. In such settings, it is generally reasoned that particles entering a Weibel generated turbulence are trapped inside it, provided their Larmor radius in the peak field is smaller than the field coherence length. The goal of this work is to put this heuristic conclusion on firm ground by studying, both analytically and numerically, such motion. A toy model is analyzed, consisting of a relativistic particle entering a region of space occupied by a spatially harmonic field. The particle penetrates the magnetic structure in a direction aligned with the magnetic filaments. Although the conclusions are not trivial, the main result is confirmed
Particles trajectories in magnetic filaments
Bret, A.
2015-07-01
The motion of a particle in a spatially harmonic magnetic field is a basic problem involved, for example, in the mechanism of formation of a collisionless shock. In such settings, it is generally reasoned that particles entering a Weibel generated turbulence are trapped inside it, provided their Larmor radius in the peak field is smaller than the field coherence length. The goal of this work is to put this heuristic conclusion on firm ground by studying, both analytically and numerically, such motion. A toy model is analyzed, consisting of a relativistic particle entering a region of space occupied by a spatially harmonic field. The particle penetrates the magnetic structure in a direction aligned with the magnetic filaments. Although the conclusions are not trivial, the main result is confirmed.
Pion production and particle correlations
International Nuclear Information System (INIS)
Kristiansson, P.
1985-10-01
Intermediate energy heavy ion collisions have been studied using the carbon-beam produced at the CERN SC-accelerator. Cross-sections for π + and π - have been measured over a wide range of large angles at 60, 75 and 86 MeV/nucleon. The yields and shapes are compared to a nucleon-nucleon scattering approach, which underestimates the yields by orders of magnitude. The π - /π + -ratio observed is close to unity for 12 C + 12 C, but the enhancement for 12 C + 208 Pb is much larger than expected from the neutron excess in 208 Pb. Large-angle light-particle correlations for 86 MeV/nucleon carbon induced reactions on different targets (C, Al, Cu, Au) have been studied. An excess of correlations is observed in the particle-particle scattering plane. The strength of this effect increases with observed particle mass and decreases with target mass. (author)
Particles trajectories in magnetic filaments
Energy Technology Data Exchange (ETDEWEB)
Bret, A. [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain)
2015-07-15
The motion of a particle in a spatially harmonic magnetic field is a basic problem involved, for example, in the mechanism of formation of a collisionless shock. In such settings, it is generally reasoned that particles entering a Weibel generated turbulence are trapped inside it, provided their Larmor radius in the peak field is smaller than the field coherence length. The goal of this work is to put this heuristic conclusion on firm ground by studying, both analytically and numerically, such motion. A toy model is analyzed, consisting of a relativistic particle entering a region of space occupied by a spatially harmonic field. The particle penetrates the magnetic structure in a direction aligned with the magnetic filaments. Although the conclusions are not trivial, the main result is confirmed.
Weak Decays of Charmed Particles
Energy Technology Data Exchange (ETDEWEB)
Turcotte, Marc Gilles [McGill Univ., Montreal, QC (Canada)
1986-05-01
The lifetimes of charmed particles produced in interactions of high energy neutrinos with nucleons have been measured using a combination of a very high resolution emulsion-based vertex detector and a spectrometer allowing full kinematical reconstruction of the decays.
Habitat Particle Impact Monitoring System
National Aeronautics and Space Administration — The purpose of this project is the development of particle impact detection technology for application to habitable space exploration modules, both in space and on...
Particle Physics and Programming Languages
Watts, Gordon
2017-01-01
A SeaLang meetup - a presentation discussing various programming languages used in particle physics, from pushing common modern languages a bit past where they should be pushed, to an embedded DSL, to some full blown ones written.
Charged particle traps II applications
Werth, Günther; Major, Fouad G
2009-01-01
This, the second volume of Charged Particle Traps, is devoted to applications, complementing the first volume’s comprehensive treatment of the theory and practice of charged particle traps, their many variants and refinements. In recent years, applications of far reaching importance have emerged ranging from the ultra-precise mass determinations of elementary particles and their antiparticles and short-lived isotopes, to high-resolution Zeeman spectroscopy on multiply-charged ions, to microwave and optical spectroscopy, some involving "forbidden" transitions from metastable states of such high resolution that optical frequency standards are realized by locking lasers to them. Further the potential application of trapped ions to quantum computing is explored, based on the extraordinary quantum state coherence made possible by the particle isolation. Consideration is given to the Paul and Penning traps as potential quantum information processors.
Study of heavy flavored particles
International Nuclear Information System (INIS)
1991-01-01
This report discusses progress on the following topics: time-of- flight system; charmed baryon production and decays; D decays to baryons; measurement of sigma plus particles magnetic moments; and strong interaction coupling
International Nuclear Information System (INIS)
1976-01-01
An attempt is made to discuss systematics of new particles and their spectroscopy in a simple manner. The main emphasis is on charm and SU(4), weak decays of charmed mesons, hadronic masses, and charmonium
Model building and new particles
International Nuclear Information System (INIS)
Frampton, P.H.
1992-01-01
After an outline of the Standard Model, indications of new physics beyond it are discussed. The nature of model building is illustrated by three examples which predict, respectively, new particles called the axigluon, sarks and the aspon. (author). 11 refs