Static and dynamical properties of light hadrons in QCD
International Nuclear Information System (INIS)
Ioffe, B.L.
1984-01-01
The review of QCD determination of static and dynamical properties of hadrons is given. Hadron masses, their transition constants into quark currents, meson formfactors at intermediate momentum transfers, mesonic partial widths and structure functions at small x are considered. A special attention is paid to calculation of static paramaters of hadrons in external fields (nucleon and hyperon magnetic moments, interaction constants with axial currents)
Hadron static properties in the model considering the structure of QCD vacuum
International Nuclear Information System (INIS)
Dorokhov, A.E.; Kochelev, N.I.
1987-01-01
The model taking into account the interaction of quarks with QCD vacuum fields is applied to calculate the mean-square charge radii, magnetic moments and axial-vector constants of the hadron interaction. It is shown that one-particle contributions of these characteristics describe the experimental data with 20% accuracy
Structure of hadrons. Proceedings
International Nuclear Information System (INIS)
Feldmeier, H.; Knoll, J.; Noerenberg, W.; Wambach, J.
2001-01-01
The following topics were dealt with: Hadronic reactions and resonances, structure of mesons, baryons, glueballs, and hybrids, physics with strange and charmed quarks, future projects and facilities. (HSI)
International Nuclear Information System (INIS)
De, S.S.
1989-01-01
The paper deals with the space-time structure of the sub-atomic world and attempts to construct the fields of the constitutents of the hadrons. Then it is attempted to construct the fields of the hadrons from these micro-fields. (autho r). 24 refs
International Nuclear Information System (INIS)
Martin, F.
1981-03-01
The x dependence of hadron structure functions is investigated. If quarks can exist in very low mass states (10 MeV for d and u quarks) the pion structure function is predicted to behave like (1-x) and not (1-x) 2 in a x-region around 1. Relativistic and non-relativistic quark bound state pictures of hadrons are considered together with their relation with the Q 2 evolution of structure functions. Good agreement with data is in general obtained
International Nuclear Information System (INIS)
Kaplan, D.B.
1995-01-01
I give a brief and selective overview of QCD as it pertains to determining hadron structure, and the relevant directions in this field for nuclear theory. This document is intended to start discussion about priorities, not end it
International Nuclear Information System (INIS)
Chela-Flores, J.
1981-08-01
A many-body approach to hadron structure is presented, in which we consider two parton species: spin-0 (b-partons), and spin-1/2 (f-partons). We extend a boson and a fermion pairing scheme for the b-, and f-partons respectively, into a Yang-Mills gauge theory. The main feature of this theory is that the gauge field is not identified with the usual gluon field variable in QCD. We study the confinement problem of the hadron constituents, and obtain, for low temperatures, partons that are confined by energy gaps. As the critical temperatures for the corresponding phase transitions are approached, the energy gap gradually disappears, and confinement is lost. The theory goes beyond the non-relativistic harmonic oscillator quark model, in the sense of giving physical reasons why a non-relativistic approximation is adequate in describing the internal dynamics of hadron structure. (author)
International Nuclear Information System (INIS)
Ferreira, P.L.
1984-01-01
An overview of the current phenomenological models of hadron structure, whose theoretical basis is the Quantum Chromodynamics (QCD), is presented. A short introduction to the QCD permits to focalize the relevant properties which are attached to those models. Following, bag-like models (in particular, MIT bag and chiral extensions) and potential-like models among them the Karl and Isgur non-relativistic model and a semi-relativistic model, free of the Klein paradox, with equal scalar-vetorial mixture of confinement potential are shortly studied. Enphasis is given to the baryons, treated, basically, as three-quarks systems. (L.C.) [pt
Summary of static properties of leptons and hadrons
International Nuclear Information System (INIS)
Franklin, J.
1989-01-01
The session on Static Properties of Leptons and Hadrons had six talks on baryon magnetic moments (four experimental and two theoretical) and three talks on other topics (g/2 of the electron, g-2 of the muon, and a search for an electric dipole moment of the neutron). I will first give brief summaries of these last three talks and then present an overview of baryon magnetic moments, updated by the results presented at this symposium
Hadron structure from lattice QCD
International Nuclear Information System (INIS)
Schaefer, Andreas
2008-01-01
Some elements and current developments of lattice QCD are reviewed, with special emphasis on hadron structure observables. In principle, high precision experimental and lattice data provide nowadays a very detailled picture of the internal structure of hadrons. However, to relate both, a very good controle of perturbative QCD is needed in many cases. Finally chiral perturbation theory is extremely helpful to boost the precision of lattice calculations. The mutual need and benefit of all four elements: experiment, lattice QCD, perturbative QCD and chiral perturbation theory is the main topic of this review
Hadronic collision and hadronic structure (an experimental review)
International Nuclear Information System (INIS)
Davier, M.
1975-01-01
In this set of lectures an attempt is made to present a survey of the available experimental data on hadronic collisions at large transverse momentum, together with their current phenomenological descriptions. In particular, the experimental confirmation of constituent structure is looked at in a critical way. The emphasis throughout is to let the data speak in the most unbiased way and to gather evidence as to the short range structure of the hadronic interactions. Finally the current information on lepton production in hadronic collisions is reviewed
Hadronic Structure from Perturbative Dressing
Energy Technology Data Exchange (ETDEWEB)
Arash, Firooz [Physics Department, Tafresh University, Tafresh, Iran and Center for theoretical physics and Mathematics, AEOI, P.O. Box 11365-8486, Tehran (Iran, Islamic Republic of)]. E-mail: farash@cic.aut.ac.ir
2005-09-15
Perturbative dressing of a valence quark in QCD produces the internal structure of an extended object, the so-called Valon. The valon structure is universal and independent of the hosting hadron. Polarized and unpolarized proton and pion structure functions are calculated in the valon representation. One finds that although all the available data on g{sub 1}{sup p,n,d} are easily reproduced, a sizable orbital angular momentum associated with the partonic structure of the valon is required in order to have a spin 1/2 valon.
Statics and Mechanics of Structures
DEFF Research Database (Denmark)
Krenk, Steen; Høgsberg, Jan Becker
The statics and mechanics of structures form a core aspect of civil engineering. This book provides an introduction to the subject, starting from classic hand-calculation types of analysis and gradually advancing to a systematic form suitable for computer implementation. It starts with statically...
Statics and mechanics of structures
Krenk, Steen
2013-01-01
The statics and mechanics of structures form a core aspect of civil engineering. This book provides an introduction to the subject, starting from classic hand-calculation types of analysis and gradually advancing to a systematic form suitable for computer implementation. It starts with statically determinate structures in the form of trusses, beams and frames. Instability is discussed in the form of the column problem - both the ideal column and the imperfect column used in actual column design. The theory of statically indeterminate structures is then introduced, and the force and deformation methods are explained and illustrated. An important aspect of the book’s approach is the systematic development of the theory in a form suitable for computer implementation using finite elements. This development is supported by two small computer programs, MiniTruss and MiniFrame, which permit static analysis of trusses and frames, as well as linearized stability analysis. The book’s final section presents related ...
International Nuclear Information System (INIS)
Migdal, A.B.; Khokhlachev, S.B.; Borue, V.Yu.
1989-01-01
The hadron is considered as a stringlike gluon drop with a quark and antiquark near the ends of the 'string' for a meson and with the antiquark replaced by a diquark for a baryon. The softer 'string' modes are the rotations and the longitudinal vibrations. Quantization of these modes enables to describe the hadron spectra. (orig.)
Spin structure of hadronization products
International Nuclear Information System (INIS)
Clavelli, L.
1979-03-01
We point out that the hypothesis of soft hadronization together with Lorentz invariance strongly constrain the hadronization process ine + e - annihilation. A final stage jet hypothesis is made which satisfies these constraints. The resulting picture leads to testable predictions not obtainable from perturbative QCD. (orig.) [de
Leptons as a probe of hadronic structure
International Nuclear Information System (INIS)
Gilman, F.J.
1976-04-01
Lectures are given on some of the theoretical ideas involved in electroproduction, neutrino production and electron--positron annihilation into hadrons. In so doing a study is simultaneously made of both the short distance behavior of products of currents and hadron structure. 56 references
Static and Dynamic Membrane Structures
Directory of Open Access Journals (Sweden)
Sergiu Ivanov
2012-10-01
Full Text Available While originally P systems were defined to contain multiset rewriting rules, it turned out that considering different types of rules may produce important results, such as increasing the computational power of the rules. This paper focuses on factoring out the concept of a membrane structure out of various P system models with the goal of providing useful formalisations. Both static and dynamic membrane structures are considered.
Hadron Structure '87. Volume 14
International Nuclear Information System (INIS)
Krupa, D.
1988-01-01
Out of the 21 papers and 41 short communications presented at the conference, the proceedings contain the full texts of 12 papers and 35 short communications. All these contributions have been inputted to INIS. The topics covered include nonperturbative calculations in the field theory, in QCD in particular; particle production in hadron-nucleus and nucleus-nucleus collisions and the quark-gluon plasma; and recent experimental results in the field. (A.K.)
Light-cone quantization and hadron structure
International Nuclear Information System (INIS)
Brodsky, S.J.
1996-04-01
Quantum chromodynamics provides a fundamental description of hadronic and nuclear structure and dynamics in terms of elementary quark and gluon degrees of freedom. In practice, the direct application of QCD to reactions involving the structure of hadrons is extremely complex because of the interplay of nonperturbative effects such as color confinement and multi-quark coherence. In this talk, the author will discuss light-cone quantization and the light-cone Fock expansion as a tractable and consistent representation of relativistic many-body systems and bound states in quantum field theory. The Fock state representation in QCD includes all quantum fluctuations of the hadron wavefunction, including fax off-shell configurations such as intrinsic strangeness and charm and, in the case of nuclei, hidden color. The Fock state components of the hadron with small transverse size, which dominate hard exclusive reactions, have small color dipole moments and thus diminished hadronic interactions. Thus QCD predicts minimal absorptive corrections, i.e., color transparency for quasi-elastic exclusive reactions in nuclear targets at large momentum transfer. In other applications, such as the calculation of the axial, magnetic, and quadrupole moments of light nuclei, the QCD relativistic Fock state description provides new insights which go well beyond the usual assumptions of traditional hadronic and nuclear physics
Department of Hadron Structure - Overview
International Nuclear Information System (INIS)
Eskreys, A.
2000-01-01
research program and the detector construction has been continued with the goal to be ready by 2005. Department XII is involved in the preparation of the project of the luminosity detector. TESLA is the project of the new generation high energy e + e - linear collider, planned to be built in Hamburg. Our engineers prepared the final version of electronic board which will be used in the control system of cavities for TESLA project. The analysis of the data from the two presently continued experiments (ZEUS, D0) cover the program of research ranging from the exploration of the structure of the matter in photoproduction, deep inelastic e ± p scattering and (anti)pp collisions through the searches of the exotic and rare processes (W, Z, top, leptoquarks production) to the new approach to the traditional subject like properties of the pion emission source or property of the hadronic final states. Above outsketched research has resulted in 1999 in 29 publications in the renown scientific periodicals. (author)
International Nuclear Information System (INIS)
Lukac, I.
1985-01-01
The proceedings, published in two volumes, include 18 invited lectures and reports presented at the conference as well as 36 short communications. The conference divided into general sessions and three parallel sessions, dealt not only with the structure of hadrons but also with a number of related topics. (A.K.)
Quark-model study of the hadron structure and the hadron-hadron interaction
International Nuclear Information System (INIS)
Valcarce, A; Caramés, T F; Vijande, J; Garcilazo, H
2011-01-01
Recent results of hadron spectroscopy and hadron-hadron interaction within a quark model framework are reviewed. Higher order Fock space components are considered based on new experimental data on low-energy hadron phenomenology. The purpose of this study is to obtain a coherent description of the low-energy hadron phenomenology to constrain QCD phenomenological models and try to learn about low-energy realizations of the theory.
Dynamical structure of hadron emission sources
Zhao Xi; Zhao Shu Song
2000-01-01
NA22 experimental data of the triplet seagull effects show that the Doppler effects of hadron emission sources exist exactly in hadron- hadron collisions. Every source possesses the same average energy (CMS) approximately. The collective seagull effects can be also explained by the (aQ)/sup nu /K/sub nu / (aQ) distributions (generalized functions). The dynamical structure of a hadron emission source is described by the (aQ)/sup nu /K/sub nu / (aQ) distributions. The anomalous dimensions of the pionic quantum fields are gamma /sub B/(g/sub R/)=-0.045+or-0.012, which control the singularities of the production amplitude in quantum field theory. The mathematical parameter epsilon =4-D (the dimension D of space time) in the Feynman integrals can be replaced by the anomalous gamma /sub B/(g/sub R/) of the quantum fields for the regularization. (-2 gamma /sub B/(g/sub R/) to or from epsilon /2=1/ln( Lambda /sup 2//m /sup 2/) Lambda to infinity ). (26 refs).
Dynamical structure of hadron emission sources
International Nuclear Information System (INIS)
Zhao Xi; Huang Bangrong; Zhao Shusong
2000-01-01
NA22 experimental data of the triplet seagull effects show that the Doppler effects of the hadron emission sources exist exactly in the hadron-hadron collisions. Every source possesses the same average energy (CMS) approximately. The collective seagull effects can be also explained by the (aQ) ν K ν (aQ) distributions (Generalized functions). The dynamical structure of a hadron emission source is described by the (aQ) ν K ν (aQ) distributions. The anomalous dimensions of the pionic quantum fields are γ B (g R ) = - 0.045 +- 0.012, which control the singularities of the production amplitude in quantum field theory. The mathematical parameter ε = 4-D (the dimension D of space time) in the Feynman integrals can be replaced by the anomalous γ B (g R ) of the quantum fields for the regularization. (-2γ B (g R )↔ε/2 1/ln(Λ 2 /m 2 )Λ→∞)
Unraveling hadron structure with generalized parton distributions
Energy Technology Data Exchange (ETDEWEB)
Andrei Belitsky; Anatoly Radyushkin
2004-10-01
The recently introduced generalized parton distributions have emerged as a universal tool to describe hadrons in terms of quark and gluonic degrees of freedom. They combine the features of form factors, parton densities and distribution amplitudes - the functions used for a long time in studies of hadronic structure. Generalized parton distributions are analogous to the phase-space Wigner quasi-probability function of non-relativistic quantum mechanics which encodes full information on a quantum-mechanical system. We give an extensive review of main achievements in the development of this formalism. We discuss physical interpretation and basic properties of generalized parton distributions, their modeling and QCD evolution in the leading and next-to-leading orders. We describe how these functions enter a wide class of exclusive reactions, such as electro- and photo-production of photons, lepton pairs, or mesons.
Superconformal Algebraic Approach to Hadron Structure
Energy Technology Data Exchange (ETDEWEB)
de Teramond, Guy F. [Univ. of Costa Rica, San Pedro (Costa Rica); Brodsky, Stanley J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Deur, Alexandre [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Dosch, Hans Gunter [Heidelberg Univ. (Germany). Inst. for Theoretische Physik; Sufian, Raza Sabbir [Univ. of Kentucky, Lexington, KY (United States)
2017-03-01
Fundamental aspects of nonperturbative QCD dynamics which are not obvious from its classical Lagrangian, such as the emergence of a mass scale and confinement, the existence of a zero mass bound state, the appearance of universal Regge trajectories and the breaking of chiral symmetry are incorporated from the onset in an effective theory based on superconformal quantum mechanics and its embedding in a higher dimensional gravitational theory. In addition, superconformal quantum mechanics gives remarkable connections between the light meson and nucleon spectra. This new approach to hadron physics is also suitable to describe nonperturbative QCD observables based on structure functions, such as GPDs, which are not amenable to a first-principle computation. The formalism is also successful in the description of form factors, the nonperturbative behavior of the strong coupling and diffractive processes. We also discuss in this article how the framework can be extended rather successfully to the heavy-light hadron sector.
Hadron structure with light dynamical quarks
International Nuclear Information System (INIS)
Edwards, R.G.; Richards, D.G.; Fleming, G.T.; Haegler, P.; Negele, J.W.; Orginos, K.; Pochinsky, A.; Renner, D.B.; Schroers, W.
2005-09-01
Generalized parton distributions encompass a wealth of information concerning the three-dimensional quark and gluon structure of the nucleon, and thus provide an ideal focus for the study of hadron structure using lattice QCD. The special limits corresponding to form factors and parton distributions are well explored experimentally, providing clear tests of lattice calculations, and the lack of experimental data for more general cases provides opportunities for genuine predictions and for guiding experiment. We present results from hybrid calculations with improved staggered (Asqtad) sea quarks and domain wall valence quarks at pion masses down to 350 MeV. (orig.)
Hadronic interaction and structure of exotic nuclei
International Nuclear Information System (INIS)
Otsuka, Takaharu
2009-01-01
I will overview recent studies on the evolution of the shell structure in stable and exotic nuclei, and will show its relevance to hadronic interaction, including nuclear forces. This shell evolution is primarily due to the tensor force. The robust mechanism and some examples will be presented. Such examples include the disappearance of existing magic numbers and the appearance of new ones. The shell structure and existing limit of nuclei depend also on the three-body interaction in a specific way. I will sketch how the Δ-hole excitation induced three-body force (Fujita-Miyazawa force) modifies them. (author)
Particle production from nuclear targets and the structure of hadrons
International Nuclear Information System (INIS)
Bialas, A.
Production processes from nuclear targets allow studying interactions of elementary hadronic constituents in nuclear matter. The information thus obtained on the structure of hadrons and on the properties of hadronic constituents is presented. Both soft (low momentum transfer) and hard (high momentum transfer) processes are discussed. (author)
Spin as a probe of hadron structure
International Nuclear Information System (INIS)
Ali, R.
1995-01-01
In this thesis, hadron structure was explored by studying three problems. In each case some underlying hard process, or a characteristic hard momentum, yielded important physical information such as structure and fragmentation functions describing hadrons. This provided a test of QCD predictions. In the first problem, spin dependent quark structure functions were estimated for nuclei. The multipole L=2 structure function, measurable in deeply inelastic scattering of unpolarized leptons off a polarized J > 1 nuclear target, is a good indicator of exotic quark gluon components in the nucleus. I estimated this structure function for two different classes of nuclei light nuclei describable in an independent particle model approach, as well as for heavy nuclei described by slowly rotating collective variables. In the second problem, spin dependent gluonic structure functions in a transversely polarized proton were identified and the classification according to twist was discussed. I found that there were two twist three transverse spin gluonic structure functions, called herein H1(x,Q2) and H2(x,Q2). Cross section formulae were calculated for a variety of polarization states, assuming a simple effective interaction for X2 production from gluon fusion. In the third, and final problem, the emphasis shifted from spin dependent structure functions of polarised hadrons to the formulation of an effective, low energy, field theory of s wave quarkonia, constituent heavy quarks, and gluons. and radiative transitions were shown to be easily recovered. The light-cone gluon momentum distribution at very small x was calculated and shown to be uniquely determined by the non relativistic wave function. I found that the emission of low momentum gluons made this process quite sensitive to assumptions about the binding energy of heavy quarks in quarkonia. This gauge invariant theory is extend able to p-wave quarkonia where the non locality of the meson state is enhanced by the
Ultra-peripheral collisions and hadronic structure
Klein, Spencer R.
2017-11-01
Ultra-peripheral collisions are the energy frontier for photon-mediated interactions, reaching, at the Large Hadron Collider (LHC), γ - p center of mass energies five to ten times higher than at HERA and reaching γγ energies higher than at LEP. Photoproduction of heavy quarkonium and dijets in pp and pA collisions probes the gluon distribution in protons at Bjorken-x values down to 3 ×10-6, far smaller than can be otherwise studied. In AA collisions, these reactions probe the gluon distributions in heavy ions, down to x values of a few 10-5. Although more theoretical work is needed to nail down all of the uncertainties, inclusion of these data in current parton distribution function fits would greatly improve the accuracy of the gluon distributions at low Bjorken-x and low/moderate Q2. High-statistics ρ0 data probe the spatial distribution of the interaction sites; the site distribution is given by the Fourier transform of dσ / dt. After introducing UPCs, this review presents recent measurements of dilepton production and light-by-light scattering and recent data on proton and heavy nuclei structure, emphasizing results presented at Quark Matter 2017 (QM2017).
Hadron Azimuthal Correlations and Mach-like Structures in a Partonic/Hadronic Transport Model
International Nuclear Information System (INIS)
Ma, G.L.; Zhang, S.; Ma, Y.G.; Cai, X.Z.; Chen, J.H.; He, Z.J.; Huang, H.Z.; Long, J.L.; Shen, W.Q.; Shi, X.H.; Zhong, C.; Zuo, J.X.
2007-01-01
With a multi-phase transport model (AMPT) with both partonic and hadronic interactions, two- and three-particle azimuthal correlations in Au + Au collisions at s NN =200 GeV have been studied by the mixing-event technique. A Mach-like structure has been observed in two- and three-particle correlations in central collisions. It has been found that both partonic and hadronic dynamical mechanisms contribute to the Mach-like structure. However, only hadronic rescattering is unable to reproduce experimental amplitude of Mach-like structure, and parton cascade process is indispensable. The results of three-particle correlation indicate a partonic Mach-like shock wave can be produced by strong parton cascade in central Au+Au collisions
Confinement and quark structure of light hadrons
International Nuclear Information System (INIS)
Efimov, G.V.; Ivanov, M.A.
1988-01-01
We present a quark confinement model (QCM) for the description of the low-energy physics of light hadrons (mesons and baryons). The model is based on two hypotheses. First, the quark confinement is realized as averaging over vacuum gluon fields which are believed to provide the confinement of any colour objects. Second, hadrons are treated as collective colourless excitations of quark-gluon interactions. The description of strong, electromagnetic and weak interactions of mesons and baryons at the low energy is given from a unique point of view
A new slant on hadron structure
Indian Academy of Sciences (India)
about QCD by treating Nc as a variable, so the study of hadron properties as a ..... tions which, in the infinite momentum frame, are interpreted as probability distributions ... between strange and antistrange [22] and spin-dependent sea quark ...
Hadron structure in the ladder model
International Nuclear Information System (INIS)
Soper, D.E.
1979-01-01
The (flavor non-singlet) Green's function to find a far-off-shell quark in a hadron is obtained in the renormalization group improved ladder model for QCD in the space-like axial gauge. Particular attention is paid to the role of the singularity in the gluon propagator. 4 figures
Hadronic structure of the weak neutral current
International Nuclear Information System (INIS)
Marriner, J.P.
1977-01-01
A comparison of neutral and charged current deep inelastic neutrino interactions is made in an experiment utilizing the Fermilab 15 ft. bubble chamber. The ratio of neutral current events (NC) to charged current events (CC) is 0.35 +- 0.06 when the visible hadronic energy is greater than 10 GeV. The distributions of NC and CC in a new variable called u/sub vis/, which depends only on the observed hadrons, are given. From these distributions and the assumption that the x distribution is the same for NC and CC, it is concluded that for a NC y distribution of the form (1 - eta) + 3 eta(1 - y) 2 , eta = .12 +- .32. The ratio rho/sub NC/(rho/sub CC/) of neutron to proton cross sections in NC(CC) is studied and the quotient rho/sub NC//rho/sub CC/ = 0.7 +- 0.2. The distribution of hadrons in z/sub vis/, the scaled hadronic momentum, is given. The CC hadrons fit the predictions of the quark fragmentation functions D/sub u//sup π + /(z) and D/sub u//sup π - /(z) as given by Field and Feynman. The neutral current events fit the form (1 - lambda)D/sub u//sup π + /(z) + lambda D/sub d//sup π + /(z) for positives and (1 - lambda)D/sub u//sup π - /(z) + lambda D/sub d//sup π - /(z) for negatives with lambda = 0.56 +- 0.10 and a fit confidence level of 4%
Inclusive vector meson production and hadron structure
International Nuclear Information System (INIS)
Boeckmann, K.
1977-08-01
It is shown that J/PSI production in hadronic interactions is dominated by central production from sea quarks even at beam momenta as low as 40 GeV/c. All known experimental data on inclusive vector meson production support the hypothesis that cross sections obtained from meson-nucleon and nucleon-nucleon interactions have to be compared in the quark C.M. system. With the distinction of sea quark and valence quark interactions in the additive quark model a consistent description of inclusive rho, K*, PHI and J/PSI production in hadronic interactions. A natural connection of inclusive rho 0 production cross sections in anti pp, pp and πp interactions is obtained. (orig.) [de
Structure of the QCD vacuum and hadrons
International Nuclear Information System (INIS)
Shuryak, E.
1996-01-01
Recent studies have provided strong arguments in favor of the idea that most hadrons (including the nucleon) are actually bound not because of confining forces, but mainly due to the instanton-induced forces. Quite different effective interactions in various mesonic and baryonic channels can be explained in this way. Moreover, many hadronic parameters and even the point-to-point correlation functions are quantitatively reproduced by the simplest possible ensemble of instantons, the so-called ''Random Instanton Liquid Model'' (RILM). Recent lattice works have confirmed it, essentially deriving the ''instanton vacuum'' from lattice configuration by their ''cooling''. At non-zero temperatures the (quark-induced) interaction between instantons becomes much stronger, and at the critical temperature T=T c the chiral symmetry becomes restored, due to ''pairing'' of the instantons and the anti-instantons into a kind of ''I I molecules''. (orig.)
Topological supersymmetric structure of hadron cross sections
International Nuclear Information System (INIS)
Gauron, P.; Nicolescu, B.; Ouvry, S.
1980-12-01
Recently a way of fully implementing unitarity in the framework of a Dual Topological Unitarization theory, including not only mesons but also baryons, was found. This theory consists in the topological description of hadron interactions involving confined quarks in terms of two 2-dimensional surfaces (a closed 'quantum' surface and a bounded 'classical' surface). We show that this description directly leads, at the zeroth order of the topological expansion, to certain relations between hadron cross-sections, in nice agreement with experimental data. A new topological suppression mechanism is shown to play an important dynamical role. We also point out a new topological supersymmetry property, which leads to realistic experimental consequences. A possible topological origin of the rho and ω universality relations emerges as a by-product of our study
Static structure of active Brownian hard disks
de Macedo Biniossek, N.; Löwen, H.; Voigtmann, Th; Smallenburg, F.
2018-02-01
We explore the changes in static structure of a two-dimensional system of active Brownian particles (ABP) with hard-disk interactions, using event-driven Brownian dynamics simulations. In particular, the effect of the self-propulsion velocity and the rotational diffusivity on the orientationally-averaged fluid structure factor is discussed. Typically activity increases structural ordering and generates a structure factor peak at zero wave vector which is a precursor of motility-induced phase separation. Our results provide reference data to test future statistical theories for the fluid structure of active Brownian systems. This manuscript was submitted for the special issue of the Journal of Physics: Condensed Matter associated with the Liquid Matter Conference 2017.
Investigation of hadronic structure by solving QCD on a lattice
International Nuclear Information System (INIS)
Grandy, J.M.
1992-01-01
Various aspects of hadronic structure are investigated by means of lattice calculations. The measurements focus on equal-time quark wavefunctions, correlations of density operators, and vacuum correlators of hadronic currents, with additional measurements of Wilson loops and hadron masses as a consistency check. The wavefunctions are shown to be consistent with a confinement model prediction. The effect of hyperfine splitting on the wavefunctions is shown to agree closely with the quark model prediction. The computed quark density correlations for the pion, rho, and proton at long range are compared with the expected asymptotic behavior. The density correlation also provides a basis for comparing the spatial extent of quark pairs surrounding the hadron with the extent of the valence quark wavefunction. Vacuum correlation functions of hadronic currents are compared with phenomenological fits to experimental data and sum rule calculations. Hadronic observable calculations are performed by evaluating path integrals in imaginary time using a Monte Carlo technique. Lattices with 16 points in the time direction and spatial volume of 12 3 and 16 3 points are used. The physical lattice spacing is 0.2 fm, and the physical volume of the lattice is large enough that the effect of spatial boundary conditions on the long range structure of the particles can be corrected in a linear fashion
Space structure of hadrons and soft processes
International Nuclear Information System (INIS)
Nyiri, J.
1980-12-01
A semi-phenomenological description of soft hadronic processes is given based on the picture of spatially separated quarks and on the spectator mechanism. It is pointed out that the data on the production of secondary mesons support the assumption of quark combinatorics. It is shown that the baryon production can be described roughly by the hypothesis of the dominance of the lowest SU(6)baryon multiplet. Two ways of explaining the slight discrepancy between the experimental data and the theoretical predictions on the increase of baryon multiplicities with the increase of energy are given. (P.L.)
A quark structure of hadrons and nuclei
International Nuclear Information System (INIS)
Chakrabarty, S.; Deoghuria, S.
1992-08-01
In this review we look into the recent understanding of mesons, baryons and nuclei as few quark bound states within the framework of quantum chromodynamics (QCD). In particular, we have reviewed our understanding of the nature of confining interaction, the spin - dependence of colour forces and the role of non-perturbative effects in the study of quark forces in the potential model approach. We also give a comparative study of results obtained by several potential models with reference to the experimental data. We find that although the Lorentz nature of confinement and the nature of spin-dependent colour forces have been better understood now, only a partial understanding of these problems are obtained so far. Our study reveals that properties of baryons could be explained by the same potential model which successfully describe the mesons. However, the nuclei require chiral symmetry and non-perturbative methods for their description. We also discuss the relation between constituent, current and dynamical quark masses. We conclude that QCD motivated approaches have shown much success in explaining many results on hadronic and nuclear data. (author). 212 refs, 14 tabs
Structural Encoding of Static Single Assignment Form
DEFF Research Database (Denmark)
Gal, Andreas; Probst, Christian; Franz, Michael
2005-01-01
Static Single Assignment (SSA) form is often used as an intermediate representation during code optimization in Java Virtual Machines. Recently, SSA has successfully been used for bytecode verification. However, constructing SSA at the code consumer is costly. SSAbased mobile code transport formats...... Java bytecode. While the resulting bytecode sequence can still be directly executed by traditional Virtual Machines, our novel VM can infer SSA form and confirm its safety with virtually no overhead....... have been shown to eliminate this cost by shifting SSA creation to the code producer. These new formats, however, are not backward compatible with the established Java class-file format. We propose a novel approach to transport SSA information implicitly through structural code properties of standard...
From Static Output Feedback to Structured Robust Static Output Feedback: A Survey
Sadabadi , Mahdieh ,; Peaucelle , Dimitri
2016-01-01
This paper reviews the vast literature on static output feedback design for linear time-invariant systems including classical results and recent developments. In particular, we focus on static output feedback synthesis with performance specifications, structured static output feedback, and robustness. The paper provides a comprehensive review on existing design approaches including iterative linear matrix inequalities heuristics, linear matrix inequalities with rank constraints, methods with ...
Broken chiral symmetry and the structure of hadrons
International Nuclear Information System (INIS)
Spence, W.L.
1982-01-01
The spontaneous breaking of chiral symmetry plays a decisive role in the structure of hadrons composed of light quarks. The formalism by which the dynamics of chiral symmetry breaking and its implications for hadronic structure can be explored in a simplified world in which fully relativistic zero-bare-mass quarks interact through a chirally symmetric instantaneous confining potential is presented. By thus modeling the essentials of the chiral limit-N/sub c/ infinity limit of QCD contact is made with the successes of existent semiphenomenological models of hadrons but post assumptions which explicitly violate chiral symetry are avoided. This revised approach then makes possible a unification of the dynamics of hadron structure with the mechanism of spontaneous chiral breaking and guarantees the appearance of the correct Goldstone excitations. The chiral breaking order parameter (absolute value anti psi psi), effective quark mass, and Goldstone boson wave function are obtainable by solving a single non-linear integral equation once a potential has been prescribed. The stability of the chiral asymmetric vacuum must then be established by studying the linear eigenvalue problem which determines the spectrum of states with vacuum quantum numbers. The nature of the instability of the chiral symmetric vacuum that leads to spontaneous symmetry breaking is explained and its apparent contingency on details of the dynamics is emphasized. It is argued that a single massless fermion in a chirally symmetric potential does form bound states for which a semi-classical description is given. Coupling to vacuum pairs of such bound states occasions the possibility of chiral symmetry breakdown
From parity violation to hadronic structure and more
Jager, K; Kox, S; Lhuillier, D; Maas, F; Page, S; Papanicolas, C; Stiliaris, S; Wiele, J; 3rd International Workshop on From Parity Violation to Hadronic Structure and More (PAVI06); PAVI 06; PAVI 2006
2007-01-01
This book contains the proceedings of the third international workshop on “From Parity Violation to Hadronic Structure and more ...” which was held from May 16 to May 20, 2006, at the George Eliopoulos conference center on the Greek island of Milos. It is part of a series that started in Mainz in 2002 and was followed by a second workshop in Grenoble in 2004. While originally initiated by the extraction of the strangeness contribution to the electromagnetic form factors of the nucleon, the workshop series has continuously broadened the focus to the application of Parity Violation using hadronic probes and to Parity Violation experiments in atomic physics. Meanwhile there have been many exciting new proposals for using Parity Violation in other areas like in the search for new physics beyond the standard model or in exploring hadron structure. There are also close connections to the open question on the size of the two photon exchange amplitude. Fifty years after the 1956 proposal of Lee and Yang to test t...
Quark-hadron duality of nucleon spin structure function
International Nuclear Information System (INIS)
Dong, Y.B.
2005-01-01
Bloom-Gilman quark-hadron duality of nuclear spin structure function is studied by comparing the integral of g 1 from perturbative QCD prediction in the scaling region to the moment of g 1 in the resonance region. The spin structure function in the resonance region is estimated by the parametrization forms of non-resonance background and of resonance contributions. The uncertainties of our calculations due to those parametrization forms are discussed. Moreover, the effect of the Δ(1232)-resonance in the first resonance region and the role of the resonances in the second resonance region are explicitly shown. Elastic peak contribution to the duality is also analyzed. (orig.)
Di-hadron azimuthal correlation and Mach-like cone structure in a parton/hadron transport model
International Nuclear Information System (INIS)
Ma, G.L.; Zhang, S.; Ma, Y.G.; Huang, H.Z.; Cai, X.Z.; Chen, J.H.; He, Z.J.; Long, J.L.; Shen, W.Q.; Shi, X.H.; Zuo, J.X.
2006-01-01
In the framework of a multi-phase transport model (AMPT) with both partonic and hadronic interactions, azimuthal correlations between trigger particles and associated scattering particles have been studied by the mixing-event technique. The momentum ranges of these particles are 3 T trig T assoc T trig T assoc NN =200 GeV. A Mach-like structure has been observed in correlation functions for central collisions. By comparing scenarios with and without parton cascade and hadronic rescattering, we show that both partonic and hadronic dynamical mechanisms contribute to the Mach-like structure of the associated particle azimuthal correlations. The contribution of hadronic dynamical process cannot be ignored in the emergence of Mach-like correlations of the soft scattered associated hadrons. However, hadronic rescattering alone cannot reproduce experimental amplitude of Mach-like cone on away-side, and the parton cascade process is essential to describe experimental amplitude of Mach-like cone on away-side. In addition, both the associated multiplicity and the sum of p T decrease, while the T > increases, with the impact parameter in the AMPT model including partonic dynamics from string melting scenario
An easily implemented static condensation method for structural sensitivity analysis
Gangadharan, S. N.; Haftka, R. T.; Nikolaidis, E.
1990-01-01
A black-box approach to static condensation for sensitivity analysis is presented with illustrative examples of a cube and a car structure. The sensitivity of the structural response with respect to joint stiffness parameter is calculated using the direct method, forward-difference, and central-difference schemes. The efficiency of the various methods for identifying joint stiffness parameters from measured static deflections of these structures is compared. The results indicate that the use of static condensation can reduce computation times significantly and the black-box approach is only slightly less efficient than the standard implementation of static condensation. The ease of implementation of the black-box approach recommends it for use with general-purpose finite element codes that do not have a built-in facility for static condensation.
Extending Graphic Statics for User-Controlled Structural Morphogenesis
Fivet, Corentin; Zastavni, Denis; Cap, Jean-François; Structural Morphology Group International Seminar 2011
2011-01-01
The first geometrical definitions of any structure are of primary importance when considering pertinence and efficiency in structural design processes. Engineering history has taught us how graphic statics can be a very powerful tool since it allows the designer to take shapes and forces into account simultaneously. However, current and past graphic statics methods are more suitable for analysis than structural morphogenesis. This contribution introduces new graphical methods that can supp...
Form factors and structure functions of hadrons in parton model
International Nuclear Information System (INIS)
Volkonskij, N.Yu.
1979-01-01
The hadron charge form factors and their relation to the deep-inelastic lepton-production structure functions in the regions of asymptotically high and small momentum transfer Q 2 are studied. The nucleon and pion charge radii are calculated. The results of calculations are in good agreement with the experimental data. The K- and D-meson charge radii are estimated. In the region of asymptotically high Q 2 the possibility of Drell-Yan-West relation violation is analyzed. It is shown, that for pseudoscalar mesons this relation is violated. The relation between the proton and neutron form factor asymptotics is obtained
Structural testing for static failure, flutter and other scary things
Ricketts, R. H.
1983-01-01
Ground test and flight test methods are described that may be used to highlight potential structural problems that occur on aircraft. Primary interest is focused on light-weight general aviation airplanes. The structural problems described include static strength failure, aileron reversal, static divergence, and flutter. An example of each of the problems is discussed to illustrate how the data acquired during the tests may be used to predict the occurrence of the structural problem. While some rules of thumb for the prediction of structural problems are given the report is not intended to be used explicitly as a structural analysis handbook.
The gluon structure of hadrons and nuclei from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Shanahan, Phiala A. [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
2018-04-01
I discuss recent lattice QCD studies of the gluon structure of hadrons and light nuclei. After very briefly highlighting new determinations of the gluon contributions to the nucleon's momentum and spin, presented by several collaborations over the last year, I describe first calculations of gluon generalised form factors. The generalised transversity gluon distributions are of particular interest since they are purely gluonic; they do not mix with quark distributions at leading twist. In light nuclei they moreover provide a clean signature of non-nucleonic gluon degrees of freedom, and I present the first evidence for such effects, based on lattice QCD calculations. The planned Electron-Ion Collider, designed to access gluon structure quantities, will have the capability to test this prediction, and measure a range of gluon observables including generalised gluon distributions and transverse momentum dependent gluon distributions, within the next decade.
The gluon structure of hadrons and nuclei from lattice QCD
Shanahan, Phiala
2018-03-01
I discuss recent lattice QCD studies of the gluon structure of hadrons and light nuclei. After very briefly highlighting new determinations of the gluon contributions to the nucleon's momentum and spin, presented by several collaborations over the last year, I describe first calculations of gluon generalised form factors. The generalised transversity gluon distributions are of particular interest since they are purely gluonic; they do not mix with quark distributions at leading twist. In light nuclei they moreover provide a clean signature of non-nucleonic gluon degrees of freedom, and I present the first evidence for such effects, based on lattice QCD calculations. The planned Electron-Ion Collider, designed to access gluon structure quantities, will have the capability to test this prediction, and measure a range of gluon observables including generalised gluon distributions and transverse momentum dependent gluon distributions, within the next decade.
Measurement of the hadronic structure function of the photon
Affholderbach, Klaus
2000-01-01
The hadronic structure function of the photon, Fγ 2 , is measured using a data sample of 52.9 pb−1, recorded with the ALEPH detector at the LEP storage ring in 1997. Approximately 2100 single-tag two-photon events at a centre-of-mass energy of √s ≈ 183GeV are selected from this data sample. The data are analysed in the two Q2 ranges from 7 to 24 and from 17 to 200 GeV2 with mean values of 13.7 and 56.5 GeV2 . The measured distributions of kinematic variables are compared to different model predictions, based on the HERWIG and PHOJET Monte Carlo generators. To determine Fγ 2(x,Q2), a two-dimensional unfolding method employing the principle of maximum entropy is used. In addition to the Bjorken variable x, the variable E17 is introduced, denoting the hadronic energy measured in the polar angle range below 17◦ and is also used in the unfolding. The two-dimensional unfolding method significantly reduces the systematic errors compared to one-dimensional methods which is shown by various unfolding tests. ...
Nuclear matter descriptions including quark structure of the hadrons
International Nuclear Information System (INIS)
Huguet, R.
2008-07-01
It is nowadays well established that nucleons are composite objects made of quarks and gluons, whose interactions are described by Quantum chromodynamics (QCD). However, because of the non-perturbative character of QCD at the energies of nuclear physics, a description of atomic nuclei starting from quarks and gluons is still not available. A possible alternative is to construct effective field theories based on hadronic degrees of freedom, in which the interaction is constrained by QCD. In this framework, we have constructed descriptions of infinite nuclear matter in relativistic mean field theories taking into account the quark structure of hadrons. In a first approach, the in medium modifications of mesons properties is dynamically obtained in a Nambu-Jona-Lasinio (NJL) quark model. This modification is taken into account in a relativistic mean field theory based on a meson exchange interaction between nucleons. The in-medium modification of mesons masses and the properties of infinite nuclear matter have been studied. In a second approach, the long and short range contributions to the in-medium modification of the nucleon are determined. The short range part is obtained in a NJL quark model of the nucleon. The long range part, related to pions exchanges between nucleons, has been determined in the framework of Chiral Perturbation theory. These modifications have been used to constrain the couplings of a point coupling relativistic mean field model. A realistic description of the saturation properties of nuclear matter is obtained. (author)
Relationship between Static Stiffness and Modal Stiffness of Structures
Directory of Open Access Journals (Sweden)
Tianjian Ji Tianjian Ji
2010-02-01
Full Text Available This paper derives the relationship between the static stiffness and modal stiffness of a structure. The static stiffness and modal stiffness are two important concepts in both structural statics and dynamics. Although both stiffnesses indicate the capacity of the structure to resist deformation, they are obtained using different methods. The former is calculated by solving the equations of equilibrium and the latter can be obtained by solving an eigenvalue problem. A mathematical relationship between the two stiffnesses was derived based on the definitions of two stiffnesses. This relationship was applicable to a linear system and the derivation of relationships does not reveal any other limitations. Verification of the relationship was given by using several examples. The relationship between the two stiffnesses demonstrated that the modal stiffness of the fundamental mode was always larger than the static stiffness of a structure if the critical point and the maximum mode value are at the same node, i.e. for simply supported beam and seven storeys building are 1.5% and 15% respectively. The relationship could be applied into real structures, where the greater the number of modes being considered, the smaller the difference between the modal stiffness and the static stiffness of a structure.
Implications of confining force field structures in hard hadronic processes
International Nuclear Information System (INIS)
Bengtsson, H.-U.
1983-04-01
This thesis is centered on the study of confining force field structures in hard scattering processes. Perturbative QCD provides the means of calculating any process on the parton level, but to be able accurately to describe the actual outcome of an event, one still needs a phenomenological model for how quarks and gluons transform into observable hadrons. One such model is based on the assumption that the particles are produced by the confining fields stretched between the partons. The actual particle distributions will then depend on the topology of the confining fields. We have developed a Monte Carlo program to simulate complete events in hard scattering, and we use this to study the properties of the confining field in different trigger situations. We further look at the amount of hard processes that can be expected in experiments that trigger on transverse energy sum (calorimeter experiments). Finally, we investigate charm production within our model. (author)
Requirements for moment connections in statically indeterminate timber structures
Leijten, A.J.M.
2011-01-01
In statically indeterminate structures, connections play a vital role in the moment distribution. Demonstrated here is a method to evaluate the conditions, taking full advantage of the benefits offered by the indeterminate nature of the structures, and using the well-established, graphical beam-line
Reactance, Restoration, and Cognitive Structure: Comparative Statics
Bessarabova, Elena; Fink, Edward L.; Turner, Monique
2013-01-01
This study (N = 143) examined the effects of freedom threat on cognitive structures, using recycling as its topic. The results of a 2(Freedom Threat: low vs. high) x 2(Postscript: restoration vs. filler) plus 1(Control) experiment indicated that, relative to the control condition, high freedom threat created a boomerang effect for the targeted…
Structure functions of hadrons in the QCD effective theory
International Nuclear Information System (INIS)
Shigetani, Takayuki
1996-01-01
We study the structure functions of hadrons with the low energy effective theory of QCD. We try to clarify a link between the low energy effective theory, where non-perturbative dynamics is essential, and the high energy deep inelastic scattering experiment. We calculate the leading twist matrix elements of the structure function at the low energy model scale within the effective theory. Calculated structure functions are evoluted to the high momentum scale with the help of the perturbative QCD, and compared with the experimental data. Through the comparison of the model calculations with the experiment, we discuss how the non-perturbative dynamics of the effective theory is reflected in the deep inelastic phenomena. We first evaluate the structure functions of the pseudoscalar mesons using the NJL model. The resulting structure functions show reasonable agreements with experiments. We study then the quark distribution functions of the nucleon using a covariant quark-diquark model. We calculate three leading twist distribution functions, spin-independent f 1 (x), longitudinal spin distribution g 1 (x), and chiral-odd transversity spin distribution h 1 (x). The results for f 1 (x) and g 1 (x) turn out to be consistent with available experiments because of the strong spin-0 diquark correlation. (author)
Static structure factor of liquid parahydrogen
International Nuclear Information System (INIS)
Dawidowski, J.; Bermejo, F.J.; Ristig, M.L.; Faak, B.; Cabrillo, C.; Fernandez-Perea, R.; Kinugawa, K.; Campo, J.
2004-01-01
The single-differential neutron-scattering cross section of liquid parahydrogen has been measured at 15.2 K and 2 bars of applied pressure by means of low-energy neutron diffraction. Our experimental conditions enable the direct observation of the peak of the liquid structure factor and therefore largely improve the signal-to-noise ratio with respect to measurements carried out using higher-energy neutron diffraction. This avoids the need of performing corrections of approximate nature to the measured cross section that is dominated by molecular rotational components if measured by conventional neutron diffraction
Static electric field enhancement in nanoscale structures
Energy Technology Data Exchange (ETDEWEB)
Lepetit, Bruno, E-mail: bruno.lepetit@irsamc.ups-tlse.fr; Lemoine, Didier, E-mail: didier.lemoine@irsamc.ups-tlse.fr [Université de Toulouse, UPS, Laboratoire Collisions Agrégats Réactivité, IRSAMC, F-31062 Toulouse (France); CNRS, UMR 5589, F-31062 Toulouse (France); Márquez-Mijares, Maykel, E-mail: mmarquez@instec.cu [Université de Toulouse, UPS, Laboratoire Collisions Agrégats Réactivité, IRSAMC, F-31062 Toulouse (France); CNRS, UMR 5589, F-31062 Toulouse (France); Instituto Superior de Tecnologías y Ciencias Aplicadas, Avenida Salvador Allende 1110, Quinta de los Molinos, La Habana (Cuba)
2016-08-28
We study the effect of local atomic- and nano-scale protrusions on field emission and, in particular, on the local field enhancement which plays a key role as known from the Fowler-Nordheim model of electronic emission. We study atomic size defects which consist of right angle steps forming an infinite length staircase on a tungsten surface. This structure is embedded in a 1 GV/m ambient electrostatic field. We perform calculations based upon density functional theory in order to characterize the total and induced electronic densities as well as the local electrostatic fields taking into account the detailed atomic structure of the metal. We show how the results must be processed to become comparable with those of a simple homogeneous tungsten sheet electrostatic model. We also describe an innovative procedure to extrapolate our results to nanoscale defects of larger sizes, which relies on the microscopic findings to guide, tune, and improve the homogeneous metal model, thus gaining predictive power. Furthermore, we evidence analytical power laws for the field enhancement characterization. The main physics-wise outcome of this analysis is that limited field enhancement is to be expected from atomic- and nano-scale defects.
International Nuclear Information System (INIS)
Fischer, J.; Kolar, P.; Kundrat, V.
1988-01-01
The proceedings contain invited lectures and papers presente at the symposium. Attention was devoted to hadron interactions a high energy in QCD, to the structure and decay of hadrons, the production of hadrons and supersymmetric particles in e + e - and ep collisions, to perturbation theory in quantum field theory, and new supersymmetric extensions of relativistic algebra. (Z.J
Quasi-static structural optimization under the seismic loads
International Nuclear Information System (INIS)
Choi, W. S.; Lee, K. M.; Kim, T. W.
2001-01-01
For preliminaries to optimization of SMART under the seismic loads, a quasi-static structural optimization for elastic structures under dynamic loads is presented. An equivalent static load (ESL) set is defined as a static load set, which generates the same displacement field as that from a dynamic load at a certain time. Multiple ESL sets calculated at all the time intervals are employed to represent the various states of the structure under the dynamic load. They can cover all the critical states that might happen at arbitrary times. The continuous characteristics of a dynamic load are considered by multiple static load sets. The calculated sets of ESLs are utilized as a multiple loading condition in the optimization process. A design cycle is defined as a circulated process between an analysis domain and a design domain. The analysis domain gives the loading condition needed in the design domain. The design domain gives a new updated design to be verified by the analysis domain in the next design cycle. The design cycles are iterated until the design converges. Structural optimization with dynamic loads is tangible by the proposed method. Standard example problems are solved to verify the validity of the method
Quark structure of static correlators in high temperature QCD
Bernard, Claude; DeGrand, Thomas A.; DeTar, Carleton; Gottlieb, Steven; Krasnitz, A.; Ogilvie, Michael C.; Sugar, R. L.; Toussaint, D.
1992-07-01
We present results of numerical simulations of quantum chromodynamics at finite temperature with two flavors of Kogut-Susskind quarks on the Intel iPSC/860 parallel processor. We investigate the properties of the objects whose exchange gives static screening lengths by reconstructing their correlated quark-antiquark structure.
Quark structure of static correlators in high temperature QCD
International Nuclear Information System (INIS)
Bernard, C.; Ogilvie, M.C.; DeGrand, T.A.; DeTar, C.; Gottlieb, S.; Krasnitz, A.; Sugar, R.L.; Toussaint, D.
1992-01-01
We present results of numerical simulations of quantum chromodynamics at finite temperature with two flavors of Kogut-Susskind quarks on the Intel iPSC/860 parellel processor. We investigate the properties of the objects whose exhange gives static screening lengths by reconstructing their correlated quark-antiquark structure. (orig.)
Quark structure of static correlators in high temperature QCD
Energy Technology Data Exchange (ETDEWEB)
Bernard, C.; Ogilvie, M.C. (Washington Univ., St. Louis, MO (United States). Dept. of Physics); DeGrand, T.A. (Colorado Univ., Boulder, CO (United States). Physics Dept.); DeTar, C. (Utah Univ., Salt Lake City, UT (United States). Physics Dept.); Gottlieb, S.; Krasnitz, A. (Indiana Univ., Bloomington, IN (United States). Dept. of Physics); Sugar, R.L. (California Univ., Santa Barbara, CA (United States). Dept. of Physics); Toussaint, D. (Arizona Univ., Tucson, AZ (United States). Dept. of Physics)
1992-07-20
We present results of numerical simulations of quantum chromodynamics at finite temperature with two flavors of Kogut-Susskind quarks on the Intel iPSC/860 parellel processor. We investigate the properties of the objects whose exhange gives static screening lengths by reconstructing their correlated quark-antiquark structure. (orig.).
Charge structure of the hadronic final state in deep-inelastic muon-nucleon scattering
International Nuclear Information System (INIS)
Arneodo, M.; Ferrero, M.I.; Peroni, C.; Beaufays, J.; Jacholkowska, A.; Kellner, G.; Osborne, A.M.; Bee, C.P.; Bird, I.; Coughlan, J.; Sloan, T.; Braun, H.; Brueck, H.; Drees, J.; Edwards, A.; Krueger, J.; Montgomery, H.E.; Peschel, H.; Pietrzyk, U.; Poetsch, M.; Schneider, A.; Combley, F.; Foster, J.; Whalley, M.; Wheeler, S.; Dreyer, T.; Ernst, T.; Haas, J.; Kabuss, E.M.; Landgraf, U.; Mohr, W.; Rith, K.; Schlagboehmer, A.; Schroeder, T.; Stier, H.E.; Wallucks, W.; Figiel, J.; Gajewski, J.; Janata, F.; Poensgen, B.; Schiemann, H.; Studt, M.; Torre, A. de la; Geddes, N.; Johnson, A.S.; Loken, J.; Long, K.; Renton, P.; Taylor, G.N.; Williams, W.S.C.; Grard, F.; Windmolders, R.
1988-01-01
The general charge properties of the hadronic final state produced in μ + p and μ + d interactions at 280 GeV are investigated. Quark charge retention and local charge compensation is observed. The ratio F 2 n /F 2 p of the neutron to proton structure function is derived from the measurement of the average hadronic charge in μd interactions. (orig.)
Structural Analysis of Cabinet Support under Static and Seismic Loads
International Nuclear Information System (INIS)
Jung, Kwangsub; Lee, Sangjin; Oh, Jinho
2014-01-01
The cabinet support consists of frames including steel channels and steel square tubes. Four tap holes for screw bolts are located on the support frame of a steel channel to fix the cabinet on the support. The channels and square tubes are assembled by welded joints. The cabinet supports are installed on the outer walls of the reactor concrete island. The KEPIC code, MNF, is used for the design of the cabinet support. In this work, the structural integrity of the cabinet support is analyzed under consideration of static and seismic loads. A 3-D finite element model of the cabinet support was developed. The structural integrity of the cabinet support under postulated service loading conditions was evaluated through a static analysis, modal analysis, and response spectrum analysis. From the structural analysis results, it was concluded that the structural integrity of the cabinet support is guaranteed
Hadron physics and the structure of neutron stars
International Nuclear Information System (INIS)
Kutschera, M.
1996-09-01
The equation of state of hadronic matter in neutron stars is briefly reviewed. Uncertainties regarding the stiffness and composition of hadronic matter are discussed. Importance of poorly known short range interactions of nucleons and hyperons is emphasized. Condensation of meson fields and the role of subhadronic degrees of freedom is considered. Empirical constraints on the equation of state emerging from observations of neutron stars are discussed. The nature of the remnant of SN1987A is considered. (author)
Photon structure and the production of jets, hadrons, and prompt photons
International Nuclear Information System (INIS)
Klasen, M.
1999-01-01
We give a pedagogical introduction to hard photoproduction processes at HERA, including the production of jets, hadrons, and prompt photons. Recent theoretical developments in the three areas are reviewed. In summary, hard photoproduction processes can provide very useful information on the hadronic structure of the photon, in particular on the gluon density, which is complimentary to the information coming from deep inelastic photon-photon scattering at electron-positron colliders. Among the different hadronic final states, jets are most easily accessible experimentally and phenomenologically. On the other hand, inclusive hadron production offers the possibility to test the universality of hadron fragmentation functions and measure the photon structure down to very low values of p T and x γ . Prompt photon production suffers from a reduced cross section and limited data, but allows for the additional testing of photon fragmentation functions
Quark approach to Santilli's conjecture on hadronic structure - II
International Nuclear Information System (INIS)
Animalu, A.O.E.
1982-08-01
In this paper, we continue an earlier investigation of an exactly soluble relativistic Bohr-type model of the internal structure of the proton (three-quark baryon system) and the pion (quark-antiquark meson system), based on a realization of Santilli's conjecture that the hadronic constituents are extended (non-pointlike) objects. The model is abstracted from an expansion of a Yukawa-type potential between the valence quarks and a massive core, in which the meson or gluon exchange term has the effect of reducing the effective Bohr radius for binding to a value less than the radius of the strong charge sphere (or Compton wavelength) of each constituent, so that appreciable overlap of charge volumes occurs, to within a typical distance of order 0.25F or 1/(800 MeV) in qqq-system, and order 1/(1200 MeV) in qq-bar-system, which are comparable to gluon masses, msub(G) approx.= 800 to 1200 MeV, required by the lattice QCD and the MIT Bag Model. Based on the assumptions that the ground state of the proton has 1s 2 2s valence quark configuration, the non-strange quark mass is msub(p)/3, and the dimensionless strong coupling constant of the Yukawa-type potential is g 2 =1, the mass of the proton core is determined self-consistently to be 2470 MeV, exactly balancing the quark binding energy so that the valence quarks appear free. The model correctly predicts the masses of the well-known resonant states of the proton with Jsup(P)=1/2 + as excited states associated with the configuration 1s2s 2 and predicts an upper bound (spectroscopic limit) for the mass of the excited states of the proton in ns 2 ms configuration, as n→infinity and m→infinity, to be 3409 MeV. Based on a generalization of the model to qq-bar-systems, an upper bound (spectroscopic limit) for the mass of qq-bar in ns 2 configuration, as n→infinity, is found to be 3096 MeV, which is the mass of the J/psi-meson. The relation of the model to violation of time-reversal invariance (T-symmetry) by non
International Nuclear Information System (INIS)
Weisz, S.
1982-07-01
High mass dimuon hadronic production is studied. This study is aimed at pion structure determination. The device is presented. The accessible luminosity is more than one scale order beyond the preceeding experiment one. The performant beam, the great acceptance and the good high mass dimuon selection are described. Parton model is introduced. Drell-Yann mechanism is reviewed. Hadronic structure, revealed during high mass muon pair production, is presented. In particular, pion structure is determined [fr
Nuclear phenomena and the short distance structure of hadrons
International Nuclear Information System (INIS)
Brodsky, S.J.
1979-09-01
In certain cases, nuclear corrections to hadronic phenomena depend in detail on the nature of quark and gluon interactions, as well as the effects of jet development within the nuclear medium. Applications of quantum chromodynamics to fast particle production in nuclear collisions, nuclear form factors, and shadowing in deep inelastic lepton processes are reviewed. Also discussed is a new approach to particle production in hadron-nucleus, nucleus-nucleus and deep-inelastic nuclear reactions from the standpoint of a color-neutralization model. 74 references
Status and prospects for the calculation of hadron structure from lattice QCD
International Nuclear Information System (INIS)
Renner, Dru B.
2010-02-01
Lattice QCD calculations of hadron structure are a valuable complement to many experimental programs as well as an indispensable tool to understand the dynamics of QCD. I present a focused review of a few representative topics chosen to illustrate both the challenges and advances of our community: the momentum fraction, axial charge and charge radius of the nucleon. I will discuss the current status of these calculations and speculate on the prospects for accurate calculations of hadron structure from lattice QCD. (orig.)
STUDYING DEFORMATIONS OF AN FLAT TRUSS STRUCTURE STATICALLY INDETERMINATED EXTERNALLY
Directory of Open Access Journals (Sweden)
Kirsanov Mikhail Nikolaevich
2017-08-01
Full Text Available A flat statically determinate parallel-chord truss structure has a cross-shaped grid and rests upon two rigid pin-bearing supports. Loads in bars are determined in a symbol form using the method of joint isolation by the computer mathematics Maple system. The peculiarity of the considered truss structure is its external static indeterminacy. In fact, all efforts and reactions of supports can be determined from the equilibrium conditions. But the inconvenience is necessary to consider the equilibrium of all the nodes of the truss. The Ritter cross-section method is not applicable to this truss structure. The sections that cut the truss into two parts and pass through the three rods, here exist only for several rods of the extreme panels. The purpose of this paper is to calculate a truss structure with a different number of panels in analytical and numerical form. Finite element calculation method with the use of software LISA 8.0 is applied. It’s noted that a truss structure is kinetically changeable when the number of spans is odd. The corresponding plan of probable velocities is given. In order to receive analytic dependence of deflection on the span number, the induction method and Maxwell-Moor formula has been applied. The operators of the compilation and solution of recurrence equations are involved in determining the general terms of the coefficient sequences. The formulas for calculation of loads in the most compressed bars of a truss structure were received.
International Nuclear Information System (INIS)
Sawada, Tetsuo
1980-01-01
It is explained that the low energy experiments with high precision are important sources of information to determine the inner structure of hadrons. For such purpose, the magnetic monopole model of hadron due to Schwinger is reviewed. Appearance of the strong van der Waals force between hadrons is one of the most important consequences of such a model. A technique, which enables us to separate the effect of such a long range force from that of the short range force arising from the exchanges of pions, is introduced. Present status of the related experiments are summarized, and the experiments necessary to confirm the existence of the strong van der Waals force in a clear-cut way are explained. Possible impacts to the hadron physics, when the existence of such a long range force is confirmed, are discussed. (author)
Interfacial ionic 'liquids': connecting static and dynamic structures.
Uysal, Ahmet; Zhou, Hua; Feng, Guang; Lee, Sang Soo; Li, Song; Cummings, Peter T; Fulvio, Pasquale F; Dai, Sheng; McDonough, John K; Gogotsi, Yury; Fenter, Paul
2015-01-28
It is well known that room temperature ionic liquids (RTILs) often adopt a charge-separated layered structure, i.e. with alternating cation- and anion-rich layers, at electrified interfaces. However, the dynamic response of the layered structure to temporal variations in applied potential is not well understood. We used in situ, real-time x-ray reflectivity to study the potential-dependent electric double layer (EDL) structure of an imidazolium-based RTIL on charged epitaxial graphene during potential cycling as a function of temperature. The results suggest that the graphene-RTIL interfacial structure is bistable in which the EDL structure at any intermediate potential can be described by the combination of two extreme-potential structures whose proportions vary depending on the polarity and magnitude of the applied potential. This picture is supported by the EDL structures obtained by fully atomistic molecular dynamics simulations at various static potentials. The potential-driven transition between the two structures is characterized by an increasing width but with an approximately fixed hysteresis magnitude as a function of temperature. The results are consistent with the coexistence of distinct anion- and cation-adsorbed structures separated by an energy barrier (∼0.15 eV).
Local quark-hadron duality of nucleon spin structure functions with target mass corrections
International Nuclear Information System (INIS)
Dong, Y.B. . E-mail dongyb@mail.ihep.ac.cn; Chen, D.Y.
2007-01-01
Target mass corrections to nucleon spin structure functions are analyzed. Our results show that the corrections are important to the structure functions in a large x region. Moreover, they play a remarkable role to the local quark-hadron duality of the nucleon spin structure functions in three individual inelastic resonance production regions
Results of searches for the nucleon structure displays in high energy hadron-nucleus collisions
International Nuclear Information System (INIS)
Strugalski, Z.
1984-01-01
Hadron-nucleus collision data at projectile energy from a few GeV up to about eight thousand GeV were analysed in order to find effects in which a nucleon structure manifests itself. It was found that some nucleon structure displays in incident hadron deflection in its passage through atomic nuclei and in multiple production process, at energies above about 2 GeV. The distribution of the deflection angles consists of two components, the mean free path for multiparticle production is about three times larger than the expected one. These effects may be interpreted as caused by a nucleon structure
The Time Structure of Hadronic Showers in Imaging Calorimeters with Scintillator and RPC Readout
Simon, Frank
2013-01-01
The intrinsic time structure of hadronic showers has been studied to evaluate its influence on the timing capability and on the required integration time of highly granular hadronic calorimeters in future collider experiments. The experiments have been carried with systems of 15 detector cells, using both scintillator tiles with SiPM readout and RPCs, read out with fast digitizers and deep buffers. These were installed behind the CALICE scintillator - Tungsten and RPC - Tungsten calorimeters as well as behind the CALICE semi-digital RPC - Steel calorimeter during test beam periods at the CERN SPS. We will discuss the technical aspects of these systems, and present results on the measurement of the time structure of hadronic showers in steel and tungsten calorimeters. These are compared to GEANT4 simulations, providing important information for the validation and the improvement of the physics models. In addition, a comparison of the observed time structure with scintillator and RPC active elements will be pre...
International Nuclear Information System (INIS)
Oka, Makoto
2012-01-01
Spectra of hadrons show various and complex structures due to the strong coupling constants of the quantum chromodynamics (QCD) constituting its fundamental theory. For their understandings, two parameters, i.e., (1) the quark mass and (2) their excitation energies are playing important roles. In low energies, for example, rather simple structures similar to the positronium appear in the heavy quarks such as charms and bottoms. It has been, however, strongly suggested by the recent experiments that the molecular resonant state shows up when the threshold to decay to mesons is exceeded. On the other hand, chiral symmetry and its breaking play important roles in the dynamics of light quarks. Strange quarks are in between and show special behaviors. In the present lecture, the fundamental concept of the hadron spectroscopy based on the QCD is expounded to illustrate the present understandings and problems of the hadron spectroscopy. Sections are composed of 1. Introduction, 2. Fundamental Concepts (hadrons, quarks and QCD), 3. Quark models and exotic hadrons, 4. Lattice QCD and QCD sum rules. For sections 1 to 3, only outline of the concepts is described because of the limited space. Exotic hadrons, many quark pictures of light hadrons and number of quarks in hadrons are described briefly. (S. Funahashi)
"Finger" structure of tiles in CMS Endcap Hadron Calorimeters
Afanasiev, Sergey; Danilov, Mikhail; Emeliantchik, Igor; Ershov, Yuri; Golutvin, Igor; Grinyov, B.V; Ibragimova, Elvira; Levchuk, Leonid; Litomin, Aliaksandr; Makankin, Alexander; Malakhov, Alexander; Moisenz, Petr; Nuritdinov, I; Popov, V.F; Rusinov, Vladimir; Shumeiko, Nikolai; Smirnov, Vitaly; Sorokin, Pavlo; Tarkovskiy, Evgueni; Tashmetov, A; Vasiliev, S.E; Yuldashev, Bekhzod; Zamyatin, Nikolay; Zhmurin, Petro
2015-01-01
Two CMS Endcap hadron calorimeters (HE) have been in operation for several years and contributed substantially to the success of the CMS Physics Program. The HE calorimeter suffered more from the radiation than it had been anticipated because of rapid degradation of scintillator segments (tiles) which have a high radiation flux of secondary particles. Some investigations of scintillators have shown that the degradation of plastic scintillator increases significantly at low dose rates. A proposal to upgrade up-grade the HE calorimeter has been prepared to provide a solution for survivability of the future LHC at higher luminosity and higher energy. A finger-strip plastic scintillator option has many advantages and is a lower cost alternative to keep the excellent HE performance at high luminosity. Measurements have been performed and this method has proved to be a good upgrade strategy.
Compatibility of candidate structural materials with static gallium
International Nuclear Information System (INIS)
Luebbers, P.R.; Michaud, W.F.; Chopra, O.K.
1993-01-01
Scoping tests were conducted on compatibility of gallium with candidate structural materials, e.g., Type 316 SS, Inconel 625, and Nb-5 Mo-1 Zr alloy, as well as Armco iron, Nickel 270, and pure chronimum. Type 316 stainless steel is least resistant and Nb-5 Mo-1 Zr alloy is most resistant to corrosion in static gallium. At 400 degrees C, corrosion rates are ∼4.0, 0.5, and 0.03 mm/y for Type 316 SS, Inconel 625, and Nb-5 Mo-1 Zr alloy, respectively. The pure metals react rapidly with gallium. In contrast to findings in earlier studies, pure iron shows greater corrosion than does nickel. The corrosion rates at 400 degrees C are ≥90 and 17 mm/y, respectively, for Armco iron and Nickel 270. The results indicate that at temperatures up to 400 degrees C, corrosion occurs primarily by dissolution accompanied by formation of metal/gallium intermetallic compounds
Mach-Like Structure in a Patronic-Hadronic Transport Model at RHIC Energies
International Nuclear Information System (INIS)
Ma, Y.G.; Ma, G.L.; Zhang, S.
2008-01-01
Recent RHIC experimental results indicated an exotic partonic matter may be created in central Au + Au collisions at dollars sqrt (s ( NN))dollars =200 GeV. When a parton with high transverse momentum (jet) passes through the new matter, jet will quench. The lost energy will be redistributed into the medium. Experimentally the soft scattered particles which carry the lost energy have been reconstructed via di-hadron angular correlations of charged particles and a hump structure on away side in di-hadron $ Delta phi$ correlation has been observed in central Au + Au collisions [1,2]. Some interpretations, such as Mach-cone shock wave and gluon Cherenkov-like radiation mechanism etc, have been proposed to explain the splitting behavior of the away side peaks. However, quantitative understanding of the experimental observation has yet to be established. In this work, we use a multi-phase transport (AMPT) model to make a detailed simulation for di-hadron or tri-hadron azimuthal correlation for central Au + Au collisions at dollars sqrt(s ( NN)) dollars =200 GeV. The hump structure on away side (we called Mach-like structure later) in the di-hadron and tri-hadron azimuthal correlations has been observed [3,4,5]. Furthermore, the time evolution of Mach-like structure is presented [6]. With the increasing of the lifetime of partonic matter, Mach-like structure develops by strong parton cascade process. Not only the splitting parameter but also the number of associated hadrons (dollarsN ( h) (assoc)dollars) increases with the lifetime of partonic matter and partonic interaction cross section. Both the explosion of dollarsN ( h) (assoc)dollars following the formation of Mach-like structure and the corresponding results of three-particle correlation support that a partonic Mach-like behavior can be produced by a collective coupling of partons because of the strong parton cascade mechanism. Therefore, the studies about Mach-like structure may give us some critical information
Adloff, C.; Chefdeville, M.; Drancourt, C.; Gaglione, R.; Geffroy, N.; Karyotakis, Y.; Koletsou, I.; Prast, J.; Vouters, G.; Repond, J.; Schlereth, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S.T.; Sosebee, M.; White, A.P.; Yu, J.; Eigen, G.; Thomson, M.A.; Ward, D.R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Arfaoui, A.; Benoit, M.; Dannheim, D.; Elsener, K.; Folger, G.; Grefe, C.; Ivantchenko, V.; Killenberg, M.; Klempt, W.; van der Kraaij, E.; Linssen, L.; Lucaci-Timoce, A.-I.; Münnich, A.; Poss, S.; Ribon, A.; Roloff, P.; Sailer, A.; Schlatter, D.; Sicking, E.; Strube, J.; Uzhinskiy, V.; Carloganu, C.; Gay, P.; Manen, S.; Royer, L.; Cornett, U.; David, D.; Ebrahimi, A.; Falley, G.; Feege, N.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krüger, K.; Lu, S.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubüser, C.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Fagot, A.; Tytgat, M.; Zaganidis, N.; Hostachy, J.-Y.; Morin, L.; Garutti, E.; Laurien, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Schultz-Coulon, H.-Ch.; Shen, W.; Stamen, R.; Chang, S.; Khan, A.; Kim, D.H.; Kong, D.J.; Oh, Y.D.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; Wilson, G.W.; Kawagoe, K.; Miyazaki, Y.; Sudo, Y.; Ueno, H.; Yoshioka, T.; Dauncey, P.D.; Cortina Gil, E.; Mannai, S.; Baulieu, G.; Calabria, P.; Caponetto, L.; Combaret, C.; Della Negra, R.; Ete, R.; Grenier, G.; Han, R.; Ianigro, J-C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Vander Donckt, M.; Zoccarato, Y.; Berenguer Antequera, J.; Calvo Alamillo, E.; Fouz, M.-C.; Puerta-Pelayo, J.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Rusinov, V.; Tarkovsky, E.; Kozlov, V.; Soloviev, Y.; Besson, D.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Popova, E.; Tikhomirov, V.; Gabriel, M.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Conforti di Lorenzo, S.; Cornebise, P.; Fleury, J.; Frisson, T.; van der Kolk, N.; Richard, F.; Pöschl, R.; Rouene, J.; Anduze, M.; Balagura, V.; Becheva, E.; Boudry, V.; Brient, J-C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Magniette, F.; Ruan, M.; Tran, T.H.; Videau, H.; Callier, S.; Dulucq, F.; Martin-Chassard, G.; de la Taille, Ch.; Raux, L.; Seguin-Moreau, N.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Kotera, K.; Ono, H.; Takeshita, T.; Uozumi, S.; Chai, J.S.; Song, H.S.; Lee, S.H.; Götze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.
2014-01-01
The intrinsic time structure of hadronic showers influences the timing capability and the required integration time of hadronic calorimeters in particle physics experiments, and depends on the active medium and on the absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15 small plastic scintillator tiles read out with Silicon Photomultipliers, the time structure of showers is measured on a statistical basis with high spatial and temporal resolution in sampling calorimeters with tungsten and steel absorbers. The results are compared to GEANT4 (version 9.4 patch 03) simulations with different hadronic physics models. These comparisons demonstrate the importance of using high precision treatment of low-energy neutrons for tungsten absorbers, while an overall good agreement between data and simulations for all considered models is observed for steel.
Quasi-static elastography comparison of hyaline cartilage structures
McCredie, A. J.; Stride, E.; Saffari, N.
2009-11-01
Joint cartilage, a load bearing structure in mammals, has only limited ability for regeneration after damage. For tissue engineers to design functional constructs, better understanding of the properties of healthy tissue is required. Joint cartilage is a specialised structure of hyaline cartilage; a poroviscoelastic solid containing fibril matrix reinforcements. Healthy joint cartilage is layered, which is thought to be important for correct tissue function. However, the behaviour of each layer during loading is poorly understood. Ultrasound elastography provides access to depth-dependent information in real-time for a sample during loading. A 15 MHz focussed transducer provided details from scatterers within a small fixed region in each sample. Quasi-static loading was applied to cartilage samples while ultrasonic signals before and during compressions were recorded. Ultrasonic signals were processed to provide time-shift profiles using a sum-squared difference method and cross-correlation. Two structures of hyaline cartilage have been tested ultrasonically and mechanically to determine method suitability for monitoring internal deformation differences under load and the effect of the layers on the global mechanical material behaviour. Results show differences in both the global mechanical properties and the ultrasonically tested strain distributions between the two structures tested. It was concluded that these differences are caused primarily by the fibril orientations.
The hadronic component of the photon structure function F2γ(Q2, x)
International Nuclear Information System (INIS)
Gotsman, E.
1988-01-01
The quality of the high Q 2 data presently available in photon-photon scattering, is not sufficient to allow for a unique determination of the QCD parameter Λ (as it is strongly correlated with the hadronic component of the photon). The authors show that a combination of the QPM point-like cross section and a hadronic cross section given by a simple power expansion in energy, provides a good description of the experimental photon structure function and photon-photon total cross section
Conclusions for the Xth moriond conference on the phenomenology of hadronic structure
International Nuclear Information System (INIS)
Yokosawa, A.
A summary is presented of the talks presented on the phenomenology of hadronic structure including diffractive, elastic, and diffractive--dissociation data, correlation experiments, multiplicity at large transverse momentum, high and low energy phenomenology, results from the proton synchrotron, psi production, and the np charge-exchange reaction. (U.S.)
International Nuclear Information System (INIS)
Gorodnichev, V.B.; Kachanov, V.A.; Khodyrev, V.Yu.; Kurchaninov, L.L.; Rykali, V.V.; Solovianov, V.L.; Ukhalov, M.N.
1993-01-01
The maximum shower silicon strip detectors embedded in a module of sandwich-type electromagnetic calorimeter have been tested. The position resolution at different depths of the silicon structure has been measured. The results on electron-hadron separation obtained as a byproduct in this study are presented, and possibility of their improvement is discussed. 8 refs., 10 figs., 1 tab
Evidence for jet structure in hadron production by e+e- annihilation
International Nuclear Information System (INIS)
Hanson, G.; Abrams, G.S.; Boyarski, A.M.; Breidenbach, M.; Bulos, F.; Chinowsky, W.; Feldman, G.J.; Friedberg, C.E.; Fryberger, D.; Goldhaber, G.; Hartill, D.L.; Jean-Marie, B.; Kadyk, J.A.; Larsen, R.R.; Litke, A.M.; Luke, D.; Lulu, B.A.; Luth, V.; Lynch, H.L.; Morehouse, C.C.; Paterson, J.M.; Perl, M.L.; Pierre, F.M.; Pun, T.P.; Rapidis, P.A.; Richter, B.; Sadoulet, B.; Schwitters, R.F.; Tanenbaum, W.; Trilling, G.H.; Vannucci, F.; Whitaker, J.S.; Winkelmann, F.C.; Wiss, J.E.
1975-01-01
We have found evidence for jet structure in e + e - →hadrons at center-of-mass energies of 6.2 and 7.4 GeV. At 7.4 GeV the jet-axis angular distribution integrated over azimuthal angle was determined to be proportional to 1+(0.78 +-0.12)cos 2 theta
Static Structural and Modal Analysis of Gas Turbine Blade
Ranjan Kumar, Ravi; Pandey, K. M., Prof.
2017-08-01
Gas turbine is one of the most versatile items of turbo machinery nowadays. It is used in different modes such as power generation, oil and gas, process plants, aviation, domestic and related small industries. This paper is based on the problems concerning blade profile selection, material selection and turbine rotor blade vibration that seriously impact the induced stress-deformation and structural functioning of developmental gas turbine engine. In this paper for generating specific power by rotating blade at specific RPM, blade profile and material has been decided by static structural analysis. Gas turbine rotating blade RPM is decided by Modal Analysis so that the natural frequency of blade should not match with the excitation frequency. For the above blade profile has been modeled in SOLIDWORKS and analysis has been done in ANSYS WORKBENCH 14. Existing NACA6409 profile has been selected as base model and then it is modified by bending it through 72.5° and 145°. Hence these three different blade profiles have been analyzed for three different materials viz. Super Alloy X, Nimonic 80A and Inconel 625 at three different speed viz. 20000, 40000 and 60000RPM. It is found that NACA6409 with 72.5° bent gives best result for all material at all speed. Among all the material Inconel 625 gives best result. Hence Blade of Inconel 625 having 72.5° bent profile is the best combination for all RPM.
Study the Structure of Hadrons and Quark-hadron duality with electrons up to 6 GeV energy
International Nuclear Information System (INIS)
Mkrtchyan, Hamlet
2008-01-01
The fundamental nature of matter in terms of elementary particles and their interactions is the central topic in subatomic physics. From the nuclear physics perspective, the atom consists of a cloud of electrons surrounding a positively charged nucleus, which contain protons and neutrons. Our understanding of the substructure of the matter has evolved considerably over the last hundred years. Scattering experiments beginning with Reserford, have provided invaluable insight into the fundamental building block of matter. Hadrons, i.e., nucleons or pions, are not elementary particles themselves but instead exhibit a substructure based on more fundamental particles. The incremental improvements in experimental design, coupled with progressively more sophisticated theoretical formalisms have led to our present-day understanding that all matter is constructed from combination of six quarks and six leptons. The familiar protons and neutrons which compose most matter are referred to as baryons and contain three quarks. Mesons are those particles containing a combination of a quark and anti-quark. Quark are bound together by gluons, the gauge-bosons of the strong interaction described by quantum chromodynamics (QCD). The electromagnetic interaction has proved very successful in probing the structure of the nucleon in a quest to understand the strong interactions between quarks and the gluons that bind them. In general, electron scattering experiments can be classified into elastic, inelastic and deep-inelastic scattering. Elastic scattering is characterized by the absorption of the transfered energy and three-momentum by the target without excitation.
Compatibility of ITER candidate structural materials with static gallium
International Nuclear Information System (INIS)
Luebbers, P.R.; Michaud, W.F.; Chopra, O.K.
1993-12-01
Tests were conducted on the compatibility of gallium with candidate structural materials for the International Thermonuclear Experimental Reactor, e.g., Type 316 SS, Inconel 625, and Nb-5 Mo-1 Zr alloy, as well as Armco iron, Nickel 270, and pure chromium. Type 316 stainless steel is least resistant to corrosion in static gallium and Nb-5 Mo-1 Zr alloy is most resistant. At 400 degrees C, corrosion rates are ∼4.0, 0.5, and 0.03 mm/yr for type 316 SS, Inconel 625, and Nb-5 Mo- 1 Zr alloy, respectively. The pure metals react rapidly with gallium. In contrast to findings in earlier studies, pure iron shows greater corrosion than nickel. The corrosion rates at 400 degrees C are ≥88 and 18 mm/yr, respectively, for Armco iron and Nickel 270. The results indicate that at temperatures up to 400 degrees C, corrosion occurs primarily by dissolution and is accompanied by formation of metal/gallium intermetallic compounds. The solubility data for pure metals and oxygen in gallium are reviewed. The physical, chemical, and radioactive properties of gallium are also presented. The supply and availability of gallium, as well as price predictions through the year 2020, are summarized
On the behaviour of the hadronic structure functions at x → 1
International Nuclear Information System (INIS)
Grigoryan, S.G.; Yesaybegyan, S.B.; Ter-Isaakyan, N.L.
1977-01-01
The hadronic structure functions are studied in quarkgluon model (when x=q 2 /2pq → 1, where q is the quark transferred momentum, p is the hadron momentum). For baryon octet the relations between structure functions depending on quark mass are obtained. For LAMBDA and Ψ hyperons strange quark contribution dominates at x → 1. In the case of Σ hyperons the contributions of U and S quarks are nearly of the same order. The average transverse momentum of quark with x approximately 1 turns out to be = 6 msup(2), where m is quark mass. For tne n quark bound state the behaviour of structure functions for odd n and for even n are obtained. The dependence of structure functions on the polarization of the initial particle is also analyzed. It is shown that the Λ hyperon helicity reache 3O % while for the Σ + hyperon this magnitude is equal to 15 %
The time structure of hadronic showers in calorimeters with gas and scintillator readout
Energy Technology Data Exchange (ETDEWEB)
Goecke, Philipp [Max-Planck-Institut fuer Physik, Munich (Germany); Collaboration: CALICE-D-Collaboration
2016-07-01
The focus of the CALICE collaboration is R and D of highly granular calorimeters. One of the possible applications is in a future TeV-scale linear e{sup +}e{sup -} collider for precision SM studies and for direct and indirect the search of new physics. For the hadronic sampling calorimeters subsystem, several absorbers and active material technologies are being investigated. In this frame, two similar experiments have been conducted to study the time structure of hadronic showers: FastRPC uses resistive plate chambers technology for the active layers whereas T3B is based on scintillating tiles coupled to SiPMs. The high sampling frequency of the readout, coupled to deep memory buffers, allows to carefully investigate the intrinsic time structure of hadronic showers with its prompt and delayed components. This study presents a detailed GEANT4 Montecarlo simulation of the FastRPC and T3B setups. It is aimed to reproduce test beam data acquired at CERN SPS where the setups were installed after 5λ of instrumented tungsten-based calorimeter prototypes. The main focus of the simulation lies on the physical processes involved in the time development of an hadronic showers, to asses the discrepancy that emerged in data for the two setups in the intermediate time range of 10 - 50 ns of shower development that can be explained with the neutron interactions in the medium.
Formula for Forced Vibration Analysis of Structures Using Static ...
African Journals Online (AJOL)
Some methods of dynamic analysis are based on using static factored response ... on a false assumption of direct linear variation in the stress-displacement relationship. Based on the flexible frame model and stiffness formulation a formula for ...
Pasta Structures of Quark-Hadron Phase Transition in Proto-Neutron Stars
International Nuclear Information System (INIS)
Yasutake, Nobutoshi; Maruyama, Toshiki; Tatsumi, Toshitaka
2011-01-01
We study the quark-hadron mixed phase in proto-neutron stars with the finite-size effects. In the calculations of pasta structures appeared in the mixed phase, the Gibbs conditions require the pressure balance and chemical equilibrium between two phases besides the thermal equilibrium. We find that the region of the mixed phase is limited due to thermal instability. Moreover, we study the effects of neutrinos to the pasta structures. As a result, we find that the existence of neutrinos make the pasta structures unstable, too. These characteristic features of the hadron-quark mixed phase should be important for the middle stage of the evolutions of proto-neutron stars.
International Nuclear Information System (INIS)
Hu, Bin; Hu, Ning; Cai, Yindi; Furukawa, Manabu; Matsushita, Makoto; Yuan, Weifeng; Cai, Yong; Yan, Cheng
2013-01-01
Compared to conventional metal-foil strain gauges, nanocomposite piezoresistive strain sensors have demonstrated high strain sensitivity and have been attracting increasing attention in recent years. To fulfil their ultimate success, the performance of vapor growth carbon fiber (VGCF)/epoxy nanocomposite strain sensors subjected to static cyclic loads was evaluated in this work. A strain-equivalent quantity (resistance change ratio) in cantilever beams with intentionally induced notches in bending was evaluated using the conventional metal-foil strain gauges and the VGCF/epoxy nanocomposite sensors. Compared to the metal-foil strain gauges, the nanocomposite sensors are much more sensitive to even slight structural damage. Therefore, it was confirmed that the signal stability, reproducibility, and durability of these nanocomposite sensors are very promising, leading to the present endeavor to apply them for static structural health monitoring. (paper)
Static and Dynamic Analysis in Design of Exoskeleton Structure
Ivánkova, Ol'ga; Méri, Dávid; Vojteková, Eva
2017-10-01
This paper introduces a numerical experiment of creating the load bearing system of a high rise building. When designing the high-rise building, it is always an important task to find the right proportion between the height of the building and its perceptive width from the various angles of street view. Investigated high rise building in this article was designed according to these criteria. The load bearing structure of the analysed object consists of a reinforced core, plates and steel tubes of an exoskeleton. Eight models of the building were created using the spatial variant of FEM in Scia Engineer Software. Individual models varied in number and dimensions of diagrids in the exoskeleton. In the models, loadings due to the own weight, weight of external glass cladding, and due to the wind according to the Standard, have been considered. The building was loaded by wind load from all four main directions with respect to its shape. Wind load was calculated using the 3D wind generator, which is a part of the Scia Engineer Software. For each model the static analysis was performed. Its most important criterion was the maximum or minimum horizontal displacement (rotation) of the highest point of the building. This displacement was compared with the limit values of the displacement of the analysed high-rise building. By step-by-step adding diagrids and optimizing their dimensions the building model was obtained that complied with the criteria of the Limit Serviceability State. The last model building was assessed also for the Ultimate Limit State. This model was loaded also by seismic loads for comparison with the load due to the wind.
The Time Structure of Hadronic Showers in Calorimeters with Scintillator and with Gas Readout
Szalay, Marco
2015-02-13
Hadronic showers are characterized by a rich particle structure in the spatial as well as in the time domain. The prompt component comes from relativistic fragments that deposit energy at the ns scale, while late components are associated predominantly with neutrons in the cascade. To measure the impact of these late components, two experiments, based on gaseous and plastic active layers with steel and tungsten absorbers, were set up. The different choice for the material of the active layers produces distinct responses to neutrons, and consequently to late energy depositions. After discussing the technical aspects of these systems, we present a comparison of the signals, read out with fast digitizers with deep buffers, and provide detailed information of the time structure of hadronic showers over a long sampling window.
Hadronic structure of the photon at small x in holographic QCD
Directory of Open Access Journals (Sweden)
Watanabe Akira
2016-01-01
Full Text Available We present our analysis on the photon structure functions at small Bjorken variable x in the framework of the holographic QCD. In the kinematic region, a photon can fluctuate into vector mesons and behaves like a hadron rather than a pointlike particle. Assuming the Pomeron exchange dominance, the dominant hadronic contribution to the structure functions is computed by convoluting the probe and target photon density distributions obtained from the wave functions of the U(1 vector field in the five-dimensional AdS space and the Brower-Polchinski-Strassler-Tan Pomeron exchange kernel. Our calculations are in agreement with both the experimental data from OPAL collaboration at LEP and those calculated from the parton distribution functions of the photon proposed by Glück, Reya, and Schienbein. The predictions presented here will be tested at future linear colliders, such as the planned International Linear Collider.
Study of the hadronic photon structure function $F^\\gamma_2$ at LEP
Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Easo, S; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Lacentre, P E; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lavorato, A; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Marchesini, P A; Marian, G; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Migani, D; Mihul, A; Van Mil, A J W; Milcent, H; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Moulik, T; Mount, R; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Oh, Yu D; Organtini, G; Ostonen, R; Palit, S; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Rind, O; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Vlachos, S; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F; Zilizi, G
1998-01-01
The hadronic photon structure function $F^\\gamma_2$ is studied in the reaction $\\mathrm{e^+e^-} \\rightarrow \\mathrm{e^+e^-hadrons}$ at LEP with the L3 detector. The data, collected from 1991 to 1995 at a centre-of-mass energy $\\sqrt{s} \\simeq 91 \\GeV$, correspond to an integrated luminosity of 140~pb$^{-1}$. The photon structure function $F^\\gamma_2$ is measured in the $Q^2$ interval $1.2 \\GeV^2 \\leq Q^2 \\leq 9.0 \\GeV^2$ and the $x$ interval $0.002 < x < 0.2$. $\\FF$ shows a linear growth with $\\ln Q^2$. The value of the slope $\\alpha^{-1}\\mathrm{d}\\FF(Q^2)/\\mathrm{d}\\ln{Q^2}$ is measured to be $0.079 \\pm 0.011 \\pm 0.009$.
Calculation of hadronic part of photon structure function in QCD
International Nuclear Information System (INIS)
Gorskij, A.S.; Ioffe, B.L.; Oganesyan, A.G.; Khodzhamiryan, A.Yu.
1989-01-01
The photon structure function in QCD in the intermediate region of the Bjorken variable 0.2 2 /2pq, where q 2 is the hard photon virtuality, p is the soft photon momentum) is calculated. It is shown that without introduction of fitting parameters the experimental data can be described in the range 3GeV 2 ≤Q 2 2 /Q 2 =-q 2 /not taking account for the leading logarithmic corrections. It is demonstrated that the corrections proportional to μ ν 2 > to the hard photon scattering amplitude on the longitudinal soft photon and to the Callan-Gross relation vanish. 16 refs.; 6 figs
International Nuclear Information System (INIS)
Tokarev, M.V.; Aparin, A.A.; Zborovsky, I.
2014-01-01
The concept of z-scaling previously developed for analysis of inclusive reactions in proton-proton collisions is applied for description of processes with polarized protons at the planned Spin Physics Detector NICA in Dubna. A hypothesis of self-similarity and fractality of the proton spin structure is discussed. The possibilities to extract information on spin-dependent fractal dimensions of hadrons and fragmentation process from asymmetries and coefficients of polarization transfer are justified. The double longitudinal spin asymmetry A LL of π 0 -meson production and the coefficient of the polarization transfer D LL of Λ hyperon production in proton-proton collisions measured at RHIC are analyzed in the framework of z-scaling. The spin-dependent fractal dimensions of proton and fragmentation process with polarized Λ hyperon are estimated. A study of the spin-dependent constituent energy loss as a function of transverse momentum of the inclusive hadron and collision energy is suggested.
Analyticity in a phenomenology of electro-weak structure of hadrons
International Nuclear Information System (INIS)
Dubnicka, S.; Dubnickova, A. Z.
2010-01-01
The utility of an application of the analyticity in a phenomenology of electro-weak structure of hadrons is demonstrated in a number of obtained new and experimentally verifiable results. With this aim first the problem of an inconsistency of the asymptotic behavior of vector-meson-dominance model with the asymptotic behavior of form factors of baryons and nuclei is solved generally and a general approach for determination of the lowest normal and anomalous singularities of form factors from the corresponding Feynman diagrams is reviewed. Then many useful applications by making use of the analytic properties of electro-weak form factors and amplitudes of various electromagnetic processes of hadrons are carried out. (Author)
Quark–hadron phase structure, thermodynamics, and magnetization of QCD matter
Nasser Tawfik, Abdel; Magied Diab, Abdel; Hussein, M. T.
2018-05-01
The SU(3) Polyakov linear-sigma model (PLSM) is systematically implemented to characterize the quark-hadron phase structure and to determine various thermodynamic quantities and the magnetization of quantum chromodynamic (QCD) matter. Using mean-field approximation, the dependence of the chiral order parameter on a finite magnetic field is also calculated. Under a wide range of temperatures and magnetic field strengths, various thermodynamic quantities including trace anomaly, speed of sound squared, entropy density, and specific heat are presented, and some magnetic properties are described as well. Where available these results are compared to recent lattice QCD calculations. The temperature dependence of these quantities confirms our previous finding that the transition temperature is reduced with the increase in the magnetic field strength, i.e. QCD matter is characterized by an inverse magnetic catalysis. Furthermore, the temperature dependence of the magnetization showing that QCD matter has paramagnetic properties slightly below and far above the pseudo-critical temperature is confirmed as well. The excellent agreement with recent lattice calculations proves that our QCD-like approach (PLSM) seems to possess the correct degrees of freedom in both the hadronic and partonic phases and describes well the dynamics deriving confined hadrons to deconfined quark-gluon plasma.
Intermediate and high energy nuclear reactions at the hadronic structural level
Energy Technology Data Exchange (ETDEWEB)
Slowinski, B [Institute of Physics, Warsaw, University of Technology, Poland, Institute of Atomic Energy, Swierk, (Poland)
1997-12-31
Form tens of MeV to several hundred of GeV is stretched out quite a large interval of energy when the interaction between hadrons (for instance, pion/nucleon-nucleus and nucleus-nucleus reactions) can be described by the considerably simplified way with still acceptable accuracy. This happens because in this energy region hadrons (i.e. pions, nucleons etc.) remain quasiparticles of nuclear matter mostly without revealing any internal structure, their de Broglie`s wavelength is much shorter as compared to the average intranuclear nucleon`s distance, and the energy transfers in the reaction are, on the average, significantly greater than the binding energy of nucleons inside nuclei. Consequently an approach to the analysis of these phenomena based on simple geometric and probabilistic considerations is justifiable, especially for many practical purposes, in particular, for shielding and dosimetric estimations, material behaviour prediction, as well as for the approximate evaluation of electronuclear breeding effects in different composites of target materials, for nuclear passivation problems and so on. In this work basic physical reasons of such a simplified picture of intermediate and high energy nuclear reactions are presented. The most usual phenomenological models of hadronic multiple emission/production and recent results of the cascade evaporation type models, are also discussed. 2 figs.
International Nuclear Information System (INIS)
Recami, E.; Tonin-Zanchin, V.
1991-01-01
Since more than a decade, a bi-scale, unified approach to strong and gravitational interactions has been proposed, that uses the geometrical methods of general relativity, and yielded results similar to strong gravity theory's. We fix our attention, in this note, on hadron structure, and show that also the strong interaction strength α s, ordinarily called the (perturbative) coupling-constant square, can be evaluated within our theory, and found to decrease (increase) as the distance r decreases (increases). This yields both the confinement of the hadron constituents for large values of r, and their asymptotic freedom [for small values of r inside the hadron]: in qualitative agreement with the experimental evidence. In other words, our approach leads us, on a purely theoretical ground, to a dependence of α s on r which had been previously found only on phenomenological and heuristical grounds. We expect the above agreement to be also quantitative, on the basis of a few checks performed in this paper, and of further work of ours about calculating meson mass-spectra. (author)
Su, Yen-Shuo; Liu, Yu-Hsuan; I, Lin
2012-11-01
Whether the static microstructural order information is strongly correlated with the subsequent structural rearrangement (SR) and their predicting power for SR are investigated experimentally in the quenched dusty plasma liquid with microheterogeneities. The poor local structural order is found to be a good alarm to identify the soft spot and predict the short term SR. For the site with good structural order, the persistent time for sustaining the structural memory until SR has a large mean value but a broad distribution. The deviation of the local structural order from that averaged over nearest neighbors serves as a good second alarm to further sort out the short time SR sites. It has the similar sorting power to that using the temporal fluctuation of the local structural order over a small time interval.
On the equivalent static loads approach for dynamic response structural optimization
DEFF Research Database (Denmark)
Stolpe, Mathias
2014-01-01
The equivalent static loads algorithm is an increasingly popular approach to solve dynamic response structural optimization problems. The algorithm is based on solving a sequence of related static response structural optimization problems with the same objective and constraint functions...... as the original problem. The optimization theoretical foundation of the algorithm is mainly developed in Park and Kang (J Optim Theory Appl 118(1):191–200, 2003). In that article it is shown, for a certain class of problems, that if the equivalent static loads algorithm terminates then the KKT conditions...
Effect of nucleon and hadron structure changes in-medium and its impact on observables
Energy Technology Data Exchange (ETDEWEB)
K. Saito; K. Tsushima; A.W. Thomas
2005-07-05
We study the effect of hadron structure changes in a nuclear medium using the quark-meson coupling (QMC) model. The QMC model is based on a mean field description of non-overlapping nucleon (or baryon) bags bound by the self-consistent exchange of scalar and vector mesons in the isoscalar and isovector channels. The model is extended to investigate the properties of finite nuclei, in which, using the Born-Oppenheimer approximation to describe the interacting quark-meson system, one can derive the effective equation of motion for the nucleon (or baryon), as well as the self-consistent equations for the meson mean fields.
Czech Academy of Sciences Publication Activity Database
Adloff, C.; Blaising, J.J.; Chefdeville, M.; Cvach, Jaroslav; Gallus, Petr; Havránek, Miroslav; Janata, Milan; Kvasnička, Jiří; Lednický, Denis; Marčišovský, Michal; Polák, Ivo; Popule, Jiří; Tomášek, Lukáš; Tomášek, Michal; Růžička, Pavel; Šícho, Petr; Smolík, Jan; Vrba, Václav; Zálešák, Jaroslav
2014-01-01
Roč. 9, Jul (2014), s. 1-24 ISSN 1748-0221 R&D Projects: GA MŠk LG14033 Institutional support: RVO:68378271 Keywords : hadronic calorimeter s * hadronic showers * hadronic physics models * hilicon photomultiplier Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.399, year: 2014
Effects of hadronic colour structure in quasi-elastic and charge-exchange scattering on nuclei
International Nuclear Information System (INIS)
Kopeliovich, B.Z.; Zakharov, B.G.
1986-01-01
Effects of hadronic hidden colour screening are considered in hadron-nucleus interaction. It is shown that in the quasi-free charge exchange-reaction nuclear matter becomes transparent for the scattered hadron if the momentum transfer is large enough. The available experimental data confirm this prediction of QCD
Energy Technology Data Exchange (ETDEWEB)
BLUM, T.; BOER, D.; CREUTZ, M.; OHTA, S.; ORGINOS, K.
2002-03-18
The RIKEN BNL Research Center workshop on ''Hadron Structure from Lattice QCD'' was held at BNL during March 11-15, 2002. Hadron structure has been the subject of many theoretical and experimental investigations, with significant success in understanding the building blocks of matter. The nonperturbative nature of QCD, however, has always been an obstacle to deepening our understanding of hadronic physics. Lattice QCD provides the tool to overcome these difficulties and hence a link can be established between the fundamental theory of QCD and hadron phenomenology. Due to the steady progress in improving lattice calculations over the years, comparison with experimentally measured hadronic quantities has become important. In this respect the workshop was especially timely. By providing an opportunity for experts from the lattice and hadron structure communities to present their latest results, the workshop enhanced the exchange of knowledge and ideas. With a total of 32 registered participants and 26 talks, the interest of a growing community is clearly exemplified. At the workshop Schierholz and Negele presented the current status of lattice computations of hadron structure. Substantial progress has been made during recent years now that the quenched results are well under control and the first dynamical results have appeared. In both the dynamical and the quenched simulations the lattice results, extrapolated to lighter quark masses, seem to disagree with experiment. Melnitchouk presented a possible explanation (chiral logs) for this disagreement. It became clear from these discussions that lattice computations at significantly lighter quark masses need to be performed.
Internal structure of multicomponent static spherical gravitating fluids
International Nuclear Information System (INIS)
Olson, E.; Bailyn, M.
1975-01-01
The Maxwell--Einstein equations for a fluid comprised of more than one type of particle are not a determinate system even if an equation of state is added. The problem of what the charge distribution is in such fluids is therefore also not determinate. To complete the definition of the problem, more equations are needed. We obtain these for the simple case of a static spherically symmetric multicomponent system (imbedded in a Minkowskian background) by minimizing the energy of the fluid with respect to variations in the number densities of the constituents, with the side conditions that the total number of each constituent is constant during the variations. This procedure results in a determinate set of hydrostatic equilibrium equations, the sum of which is the familiar Tolman--Oppenheimer--Volkoff equation. Some general conclusions can be drawn. For example, the necessary and sufficient condition for charge neutrality is that the mass-energy density be some (arbitrary) function of some (arbitrary) linear combination of the number densities. Thus, since it is well known that the electrons in a white dwarf star at absolute zero form a degenerate gas, there must be a charge imbalance throughout such a star. This imbalance can then be computed self-consistently. An over-all physical interpretation of the new equations is that in equilibrium at any point in the fluid the sum of the non-gravitational forces per unit energy is the same for constituent 1 as for constituent 2 and so on. This is the analog of the corresponding (Galilean) statement for gravitational forces that is valid even without equilibrium
On static triplet structures in fluids with quantum behavior
Sesé, Luis M.
2018-03-01
The problem of the equilibrium triplet structures in fluids with quantum behavior is discussed. Theoretical questions of interest to the real space structures are addressed by studying the three types of structures that can be determined via path integrals (instantaneous, centroid, and total thermalized-continuous linear response). The cases of liquid para-H2 and liquid neon on their crystallization lines are examined with path-integral Monte Carlo simulations, the focus being on the instantaneous and the centroid triplet functions (equilateral and isosceles configurations). To analyze the results further, two standard closures, Kirkwood superposition and Jackson-Feenberg convolution, are utilized. In addition, some pilot calculations with path integrals and closures of the instantaneous triplet structure factor of liquid para-H2 are also carried out for the equilateral components. Triplet structural regularities connected to the pair radial structures are identified, a remarkable usefulness of the closures employed is observed (e.g., triplet spatial functions for medium-long distances, triplet structure factors for medium k wave numbers), and physical insight into the role of pair correlations near quantum crystallization is gained.
Inherent Conservatism in Deterministic Quasi-Static Structural Analysis
Verderaime, V.
1997-01-01
The cause of the long-suspected excessive conservatism in the prevailing structural deterministic safety factor has been identified as an inherent violation of the error propagation laws when reducing statistical data to deterministic values and then combining them algebraically through successive structural computational processes. These errors are restricted to the applied stress computations, and because mean and variations of the tolerance limit format are added, the errors are positive, serially cumulative, and excessively conservative. Reliability methods circumvent these errors and provide more efficient and uniform safe structures. The document is a tutorial on the deficiencies and nature of the current safety factor and of its improvement and transition to absolute reliability.
Analytical static structure factor for a two-component system ...
Indian Academy of Sciences (India)
Marwan Al-Raeei
2018-03-29
Mar 29, 2018 ... be useful in studying biomolecular fluids and other soft matter fluids. Keywords. Ornstein–Zernike ... partial structure factor; isothermal compressibility; soft matter. PACS No. 05.20.Jj. 1. ..... computing. Users need to have ...
International Nuclear Information System (INIS)
Stepanek, P.; Stastnik, S.; Salajka, V.; Hradil, P.; Skolar, J.; Chlanda, V.
2003-01-01
The contribution presents some aspects of the static reliability of concrete structures under temperature effects and under mechanical loading. The mathematical model of a load-bearing concrete structure was performed using the FEM method. The temperature field and static stress that generated states of stress were taken into account. A brief description of some aspects of evaluation of the reliability within the primary circuit concrete structures is stated. The knowledge of actual physical and mechanical characteristics and chemical composition of concrete were necessary for obtaining correct results of numerical analysis. (author)
Static analysis of unbounded structures in object-oriented programs
Grabe, Immo
2012-01-01
In this thesis we investigate different techniques and formalisms to address complexity introduced by unbounded structures in object-oriented programs. We give a representation of a weakest precondition calculus for abstract object creation in dynamic logic. Based on this calculus we define symbolic
Continuum soil modeling in the static analysis of buried structures
International Nuclear Information System (INIS)
Julyk, L.J.; Marlow, R.S.; Moore, C.J.; Day, J.P.; Dyrness, A.D.
1993-10-01
Soil loading traditionally has been modeled as a hydrostatic pressure, a practice acceptable for many design applications. In the analyses of buried structure with predictive goals, soil compliance and load redistribution in the presence of soil plasticity are important factors to consider in determining the appropriate response of the structure. In the analysis of existing buried waste-storage tanks at the US Department of Energy's Hanford Site, three soil-tank interaction modeling considerations are addressed. First, the soil interacts with the tank as the tank expands and contracts during thermal cycles associated with changes in the heat generated by the waste material as a result of additions and subtractions of the waste. Second, the soil transfers loads from the surface to the tank and provides support by resisting radial displacement of the tank haunch. Third, conventional finite-element mesh development causes artificial stress concentrations in the soil associated with differential settlement
On the static structural design of climbing robots: part 2.
Ahmed, Ausama Hadi; Menon, Carlo
This manuscript is the second of two parts of a work investigating optimal configurations of legged climbing robots while loitering on vertical surfaces. In this Part 2, a structural analysis based on the finite element method, specifically the stiffness method, is performed to address the problem. Parameters that are investigated in this Part 2 include the inclination of both the body and the legs of the robot. Outcomes of the performed study are validated by analyzing the posture of 150 ants when loitering on vertical surfaces. The obtained validation ensures the predictions of the developed structural model are correct and can be used to identify optimal configurations of legged robots when loitering on vertical surfaces.
STRUCTURAL ANALYSIS, GEOMETRY AND STATICS OF A COACH UNFOLDING MECHANISM
Directory of Open Access Journals (Sweden)
Ovidiu ANTONESCU
2016-05-01
Full Text Available Starting from the constructive scheme of the mechanism, the kinematic scheme is drawn in three distinct positions (folded, middle and unfolded. By means of this scheme the mobility of the mechanism is calculated and the structural-topological formula of it is obtained. In the last section of the paper an algorithm of geometric calculus has been elaborated, starting from a kinematic link articulated to the base, element which is considered the driving component.
Field and structural analysis of 56 mm aperture dipole model magnets for the Large Hadron Collider
International Nuclear Information System (INIS)
Song, Naihao; Yamamoto, Akira; Shintomi, Takakazu; Hirabayashi, Hiromi; Yamaoka, Hiroshi; Terashima, A.
1996-01-01
A new dipole model magnet design has been made with an aperture of 56 mm according to re-optimization of the accelerator design for the Large Hadron Collider (LHC) to be built at CERN. A feature of symmetric/separate collar configuration in the new design proposed by KEK has been evaluated in terms of field quality and mechanical stability according to the process of the magnet fabrication, cool-down and excitations. The analysis has been carried out by using the finite element analysis code ANSYS, in linkage of field analysis with structural analysis. Effect of the deformation, due to electromagnetic force, on the field quality has been also investigated. Results of the analysis will be presented
Structural design concept and static analysis of CANDU spent fuel compact dry storage system
International Nuclear Information System (INIS)
Choi, K. S.; Yang, K. H.; Paek, C. R.; Jung, J. S.; Lee, H. Y.
2003-01-01
In this study, an structural design concept on CANDU spent fuel compact dry storage system MACSTOR/KN-400 module has been established with a view to optimally design the structural members of the system. Design loads, loading combination and structural safety criteria of the module were reviewed assuming W olsung Site. The static analysis of the module showed that compressive stress concentration due to dead load and live load occurred around the center of roof slab. Maximum stress resulted from dead load is about twice as much as the stress from live load, and structural behavior of module caused by wind load was not significant. The static analysis results will have influence on the reinforcement bar design of structural members with other structural analyses
International Nuclear Information System (INIS)
Month, M.; Weng, W.T.
1983-01-01
The objective is to investigate whether existing technology might be extrapolated to provide the conceptual framework for a major hadron-hadron collider facility for high energy physics experimentation for the remainder of this century. One contribution to this large effort is to formalize the methods and mathematical tools necessary. In this report, the main purpose is to introduce the student to basic design procedures. From these follow the fundamental characteristics of the facility: its performance capability, its size, and the nature and operating requirements on the accelerator components, and with this knowledge, we can determine the technology and resources needed to build the new facility
3D Biomimetic Magnetic Structures for Static Magnetic Field Stimulation of Osteogenesis
Irina Alexandra Paun; Roxana Cristina Popescu; Bogdan Stefanita Calin; Cosmin Catalin Mustaciosu; Maria Dinescu; Catalin Romeo Luculescu
2018-01-01
We designed, fabricated and optimized 3D biomimetic magnetic structures that stimulate the osteogenesis in static magnetic fields. The structures were fabricated by direct laser writing via two-photon polymerization of IP-L780 photopolymer and were based on ellipsoidal, hexagonal units organized in a multilayered architecture. The magnetic activity of the structures was assured by coating with a thin layer of collagen-chitosan-hydroxyapatite-magnetic nanoparticles composite. In vitro experime...
Complex dynamic and static structures in interconnected particle systems
International Nuclear Information System (INIS)
Kristiansen, Kai de Lange
2004-01-01
, and may also be a subject. for future studies. The diffusive behaviour of a cluster of a semi-large number spheres in a soft potential undergoes transitions in length scale from super diffusion via normal diffusion to sub diffusion. This analysis follows the motion of one sphere over a large time span. Knot theory can be used to get other measures of the collective behaviour, e.g. the linking number seems to be a promising measure and would be worth studying. This quantity represents the number of times the world lines from two spheres cross each other in a preferred direction of rotation. Random dense packing of spheres is a useful model for disordered and granular media. The monolayer of non-magnetic spheres in a ferro fluid is used to simulate this packing in 2D. Our experiments show packing structures similar to previous results. In 3D we have used a mechanical contraction method, paper 5, to simulate rapid sedimentation of binary mixture of spherical colloidal particles. The densities as function of sphere composition were found to be similar to results from the experiments. For a random dense packing it would be interesting to follow the idea of the excluded volume argument to explain quantitatively the density as function of size- and shape distributions. The mechanical contraction method seems to be ideal for doing these kinds of numerical calculations. The coordination number is difficult to find in a real system of colloidal particles, but is easily obtained in numerical simulations. Nucleation of a colloidal monolayer in all alternating electric field has been studied recently. The magnetic hole system may be used to show a similar behaviour in a magnetic field. With this system we can study the nucleation process from the beginning and also to investigate the nucleation rate. Preliminary experiments have also been done that show large differences in the behaviour in systems with only free spheres and systems with some obstacles or fixed spheres among the
Complex dynamic and static structures in interconnected particle systems
Energy Technology Data Exchange (ETDEWEB)
Kristiansen, Kai de Lange
2004-07-01
-Mandelbrot relation is not fully understood, and may also be a subject. for future studies. The diffusive behaviour of a cluster of a semi-large number spheres in a soft potential undergoes transitions in length scale from super diffusion via normal diffusion to sub diffusion. This analysis follows the motion of one sphere over a large time span. Knot theory can be used to get other measures of the collective behaviour, e.g. the linking number seems to be a promising measure and would be worth studying. This quantity represents the number of times the world lines from two spheres cross each other in a preferred direction of rotation. Random dense packing of spheres is a useful model for disordered and granular media. The monolayer of non-magnetic spheres in a ferro fluid is used to simulate this packing in 2D. Our experiments show packing structures similar to previous results. In 3D we have used a mechanical contraction method, paper 5, to simulate rapid sedimentation of binary mixture of spherical colloidal particles. The densities as function of sphere composition were found to be similar to results from the experiments. For a random dense packing it would be interesting to follow the idea of the excluded volume argument to explain quantitatively the density as function of size- and shape distributions. The mechanical contraction method seems to be ideal for doing these kinds of numerical calculations. The coordination number < C > is difficult to find in a real system of colloidal particles, but is easily obtained in numerical simulations. Nucleation of a colloidal monolayer in all alternating electric field has been studied recently. The magnetic hole system may be used to show a similar behaviour in a magnetic field. With this system we can study the nucleation process from the beginning and also to investigate the nucleation rate. Preliminary experiments have also been done that show large differences in the behaviour in systems with only free spheres and systems with some
Sedov, A. V.; Kalinchuk, V. V.; Bocharova, O. V.
2018-01-01
The evaluation of static stresses and strength of units and components is a crucial task for increasing reliability in the operation of vehicles and equipment, to prevent emergencies, especially in structures made of metal and composite materials. At the stage of creation and commissioning of structures to control the quality of manufacturing of individual elements and components, diagnostic control methods are widely used. They are acoustic, ultrasonic, X-ray, radiation methods and others. The using of these methods to control the residual life and the degree of static stresses of units and parts during operation is fraught with great difficulties both in methodology and in instrumentation. In this paper, the authors propose an effective approach of operative control of the degree of static stresses of units and parts of mechanical structures which are in working condition, based on recording the changing in the surface wave properties of a system consisting of a sensor and a controlled environment (unit, part). The proposed approach of low-frequency diagnostics of static stresses presupposes a new adaptive-spectral analysis of a surface wave created by external action (impact). It is possible to estimate implicit stresses of structures in the experiment due to this approach.
Energy Technology Data Exchange (ETDEWEB)
Bussche, E Vanden [Department of Radiotherapy Nuclear Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Deene, Y de [Department of Radiotherapy Nuclear Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Dubruel, P [Polymer Material Research Group, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium); Vergote, K [Department of Radiotherapy Nuclear Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Schacht, E [Polymer Material Research Group, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium); Wagter, C de [Department of Radiotherapy Nuclear Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium)
2004-01-01
Static light scattering (SLS) could be a worthy technique to perform a structure analysis of the polymer structures inside radiation sensitive gels. The information obtained with SLS is a static characterization of the particle structures inside the gel. SLS will be combined with NMR relaxometry and NMR diffusion measurements, which deliver a hydrodynamic characterization of the microstructure of the gels.
Quark models in hadron physics
International Nuclear Information System (INIS)
Phatak, Shashikant C.
2007-01-01
In this talk, we review the role played by the quark models in the study of interaction of strong, weak and electromagnetic probes with hadrons at intermediate and high momentum transfers. By hadrons, we mean individual nucleons as well as nuclei. We argue that at these momentum transfers, the structure of hadrons plays an important role. The hadron structure of the hadrons is because of the underlying quark structure of hadrons and therefore the quark models play an important role in determining the hadron structure. Further, the properties of hadrons are likely to change when these are placed in nuclear medium and this change should arise from the underlying quark structure. We shall consider some quark models to look into these aspects. (author)
Schilder, Constanze; Kohlhoff, Harald; Hofmann, Detlef; Basedau, Frank; Habel, Wolfgang R.; Baeßler, Matthias; Niederleithinger, Ernst; Georgi, Steven; Herten, Markus
2013-05-01
Static and dynamic pile tests are carried out to determine the load bearing capacity and the quality of reinforced concrete piles. As part of a round robin test to evaluate dynamic load tests, structure integrated fibre optic strain sensors were used to receive more detailed information about the strains along the pile length compared to conventional measurements at the pile head. This paper shows the instrumentation of the pile with extrinsic Fabry-Perot interferometers sensors and fibre Bragg gratings sensors together with the results of the conducted static load test as well as the dynamic load tests and pile integrity tests.
Hadron structure in a simple model of quark/nuclear matter
International Nuclear Information System (INIS)
Horowitz, C.J.; Moniz, E.J.; Negele, J.W.
1985-01-01
We study a simple model for one-dimensional hadron matter with many of the essential features needed for examining the transition from nuclear to quark matter and the limitations of models based upon hadron rather than quark degrees of freedom. The dynamics are generated entirely by the quark confining force and exchange symmetry. Using Monte Carlo techniques, the ground-state energy, single-quark momentum distribution, and quark correlation function are calculated for uniform matter as a function of density. The quark confinement scale in the medium increases substantially with increasing density. This change is evident in the correlation function and momentum distribution, in qualitative agreement with the changes observed in deep-inelastic lepton scattering. Nevertheless, the ground-state energy is smooth throughout the transition to quark matter and is described remarkably well by an effective hadron theory based on a phenomenological hadron-hadron potential
International Nuclear Information System (INIS)
Jiang, Jian-ping; Li, Dong-xu
2010-01-01
This paper is devoted to the study of the decentralized guaranteed cost static output feedback vibration control for piezoelectric smart structures. A smart panel with collocated piezoelectric actuators and velocity sensors is modeled using a finite element method, and then the size of the model is reduced in the state space using the modal Hankel singular value. The necessary and sufficient conditions of decentralized guaranteed cost static output feedback control for the reduced system have been presented. The decentralized and centralized static output feedback matrices can be obtained from solving two linear matrix inequalities. A comparison between centralized control and decentralized control is performed in order to investigate their effectiveness in suppressing vibration of a smart panel. Numerical results show that when the system is subjected to initial displacement or white noise disturbance, the decentralized and centralized controls are both very effective and the control results are very close
3D Biomimetic Magnetic Structures for Static Magnetic Field Stimulation of Osteogenesis
Directory of Open Access Journals (Sweden)
Irina Alexandra Paun
2018-02-01
Full Text Available We designed, fabricated and optimized 3D biomimetic magnetic structures that stimulate the osteogenesis in static magnetic fields. The structures were fabricated by direct laser writing via two-photon polymerization of IP-L780 photopolymer and were based on ellipsoidal, hexagonal units organized in a multilayered architecture. The magnetic activity of the structures was assured by coating with a thin layer of collagen-chitosan-hydroxyapatite-magnetic nanoparticles composite. In vitro experiments using MG-63 osteoblast-like cells for 3D structures with gradients of pore size helped us to find an optimum pore size between 20–40 µm. Starting from optimized 3D structures, we evaluated both qualitatively and quantitatively the effects of static magnetic fields of up to 250 mT on cell proliferation and differentiation, by ALP (alkaline phosphatase production, Alizarin Red and osteocalcin secretion measurements. We demonstrated that the synergic effect of 3D structure optimization and static magnetic stimulation enhances the bone regeneration by a factor greater than 2 as compared with the same structure in the absence of a magnetic field.
3D Biomimetic Magnetic Structures for Static Magnetic Field Stimulation of Osteogenesis.
Paun, Irina Alexandra; Popescu, Roxana Cristina; Calin, Bogdan Stefanita; Mustaciosu, Cosmin Catalin; Dinescu, Maria; Luculescu, Catalin Romeo
2018-02-07
We designed, fabricated and optimized 3D biomimetic magnetic structures that stimulate the osteogenesis in static magnetic fields. The structures were fabricated by direct laser writing via two-photon polymerization of IP-L780 photopolymer and were based on ellipsoidal, hexagonal units organized in a multilayered architecture. The magnetic activity of the structures was assured by coating with a thin layer of collagen-chitosan-hydroxyapatite-magnetic nanoparticles composite. In vitro experiments using MG-63 osteoblast-like cells for 3D structures with gradients of pore size helped us to find an optimum pore size between 20-40 µm. Starting from optimized 3D structures, we evaluated both qualitatively and quantitatively the effects of static magnetic fields of up to 250 mT on cell proliferation and differentiation, by ALP (alkaline phosphatase) production, Alizarin Red and osteocalcin secretion measurements. We demonstrated that the synergic effect of 3D structure optimization and static magnetic stimulation enhances the bone regeneration by a factor greater than 2 as compared with the same structure in the absence of a magnetic field.
Modelling of flexibles for structural analysis of short straight section of Large Hadron Collider
International Nuclear Information System (INIS)
Abhay Kumar; Dutta, Subhajit; Dwivedi, Jishnu; Soni, H.C.
2003-01-01
Short Straight Section (SSS) of Large hadron Collider (LRCM) is a 8-meter long structure with a diameter of 1 meter and it houses a twin quadrupole. The cryogens are fed to the Sass through a jumper connection between Cryogenic Distribution Line (QRL) and SSS. The bus bars travel through interconnection bellows to adjoining magnets. CAT is studying the structural behavior of cold mass and the cryostat when subjected to various forces imposed on the SSS under various operating conditions of LHC machine including realignment required to compensate local sinking of the floor of the tunnel during the LHC machine's lifetime. CAT did calculation of reaction forces and moments on the Short Straight Section due to presence of jumper connection last year after the experimental verification of finite element model at CERN. Subsequently, a unified Fe model consisting of cold mass, cold feet, vacuum vessel, main vacuum vessel bellows (large sleeves), magnet interconnects, jumper connection, service module and precision motion jacks is being developed for studying the structural behaviour. (author)
Hadron-hadron potentials from lattice quantum chromodynamics
International Nuclear Information System (INIS)
Rabitsch, K.
1997-10-01
Problems in nuclear physics generally involve several nucleons due to the composite structure of the atomic nucleus. To study such systems one has to solve the Schroedinger equation and therefore has to know a nucleon-nucleon potential. Experimental data and theoretical considerations indicate that nucleons consist of constituent particles, called quarks. Today, Quantum Chromodynamics (QCD) is believed to be the fundamental theory of strong interactions. Consequently, one should try to understand the nucleon-nucleon interaction from first principles of QCD. At nucleonic distances the strong coupling constant is large. Thus, a perturbative treatment of QCD low energy phenomena is not adequate. However, the formulation of QCD on a four-dimensional Euclidean lattice (lattice QCD) makes it possible to address the nonperturbative aspects of the theory. This approach has already produced valuable results. For example, the confinement of quarks in a nucleon has been demonstrated, and hadron masses have been calculated In this thesis various methods to extract the hadron-hadron interactions from first principles of lattice QCD are presented. One possibility is to consider systems of two static hadrons. A comparison of results in pure gluonic vacuum and with sea quarks is given for both the confinement and the deconfinement phase of QCD. Numerical simulations yield attractive potentials in the overlap region of the hadrons for all considered systems. In the deconfinement phase the resulting potentials are shallower reflecting the dissolution of the hadrons. A big step towards the simulation of realistic two-hadron systems on the lattice is the consideration of mesons consisting of dynamic valence quarks. This is done for the two most important fermionic discretization schemes in the pure gluonic vacuum. A calculation in coordinate space utilizing Kogut-Susskind fermions for the valence quarks yields meson-meson potentials with a long ranged interaction, an intermediate
Static contribution of the higher modes in the dynamic response of structures
International Nuclear Information System (INIS)
Barbosa, H.J.C.
1982-03-01
In the dynamic response of structures by the modal superposition method usually only the lower modes are taken into account and a procedure that could estimate the contribution due to the higher modes without calculating them would be useful. The technique which consists of assuming that the higher modes respond statically is discussed here. Structures subjected to support motion which are analysed by response spectra techniques are considered and some numerical results are presented. (Author) [pt
International Nuclear Information System (INIS)
Collins, P.D.B.; Martin, A.D.
1982-01-01
The mechanism of hadron scattering at high energies are reviewed in such a way as to combine the ideas of the parton model and quantum chromodynamics (QCD) with Regge theory and phenomenology. After a brief introduction to QCD and the basic features of hadron scattering data, scaling and the dimensional counting rules, the parton structure of hadrons, and the parton model for large momentum transfer processes, including scaling violations are discussed. Hadronic jets and the use of parton ideas in soft scattering processes are examined, attention being paid to Regge theory and its applications in exclusive and inclusive reactions, the relationship to parton exchange being stressed. The mechanisms of hadron production which build up cross sections, and hence the underlying Regge singularities, and the possible overlap of Regge and scaling regions are discussed. It is concluded that the key to understanding hadron reaction mechanisms seems to lie in the marriage of Regge theory with QCD. (author)
Low-energy neutron measurements in an iron calorimeter structure irradiated by 200 GeV/c hadrons
Energy Technology Data Exchange (ETDEWEB)
Russ, J S [Carnegie-Mellon University, Pittsburgh, PA (United States); Stevenson, G R; Fasso, A; Nielsen, M C [CERN, Geneva (Switzerland); Furetta, C; Rancoita, P G; Vismara, I [INFN, Milan (Italy)
1989-04-21
Of serious concern in the design of detectors for the new high-luminosity hadron-hadron colliders are the radiation damage effects on silicon and other detectors of low-energy neutrons produced by spallation evaporation or fission processes. Because of the lack of experimental information on the number of neutrons with energies between 0.1 and 10 MeV in the cascades originating from high-energy hadrons, an experiment was carried out using activation detector techniques to measure the neutron fluence in a cascade initiated by 200 GeV hadrons in acalorimeter-like iron structure. It was found that at the maximum of the cascade one produces approximately 3 neutrons per GeV of incident energy: some 70% of these are of energies between 0.1 and 5 MeV, the remainder are fairly uniformly distributed in energy between 5 and several hundred MeV. The number of albedo neutrons leaving the front face of the calorimeter structure was about 0.3 neutrons per GeV of incident energy with in energy distribution similar to those at cascade maximum These data confirm that neutron-induced damage will he of concern in the design of detectors for the new colliders and that further measurements and calculations are necessary for a correct assessment of this damage. (author)
The quasi-equilibrium response of MOS structures: Quasi-static factor
Okeke, M.; Balland, B.
1984-07-01
The dynamic response of a MOS structure driven into a non-equilibrium behaviour by a voltage ramp is presented. In contrast to Khun's quasi-static technique it is shown that any ramp-driven MOS structure has some degree of non-equilibrium. A quasi staticity factor μAK which serves as a measure of the degree of quasi-equilibrium, has been introduced for the first time. The mathematical model presented in the paper allows a better explanation of the experimental recordings. It is shown that this model could be used to analyse the various features of the response of the structure and that such physical parameters as the generation-rate, trap activation energy, and the effective capture constants could be obtained.
Technical study on semi-object emulation of structural statics problem
MoJun; LiuXingFu; LiuZhiYong; Shi Pin Gan
2002-01-01
Structural strength analysis depends mainly on finite element method and experiments. For complex structural system, a rather large error can be caused by some uncertain factors, such as load distributions, boundary conditions and constitutive relations in numerical analysis. At the same time, owing to the limitation of measuring and testing techniques, the strength and stiffness of key components can not be estimated by using the limited test data. To simulate stresses accurately under complex static environment, improve man-machine interactive system, and make the best use of fore- and post-processing function in graphic data processing, the combine numerical analysis with experimental technique and have developed the semi-object emulation technique to analyze the nonlinear problem of structure statics. The modern optical measuring techniques and image processing techniques are firstly used for the method to acquire displacement data of the vessel surface, and the data are used for the boundary condition to...
Overview of the 6 Meter HIAD Inflatable Structure and Flexible TPS Static Load Test Series
Swanson, Greg; Kazemba, Cole; Johnson, Keith; Calomino, Anthony; Hughes, Steve; Cassell, Alan; Cheatwood, Neil
2014-01-01
To support NASAs long term goal of landing humans on Mars, technologies which enable the landing of heavy payloads are being developed. Current entry, decent, and landing technologies are not practical for this class of payloads due to geometric constraints dictated by current launch vehicle fairing limitations. Therefore, past and present technologies are now being explored to provide a mass and volume efficient solution to atmospheric entry, including Hypersonic Inflatable Aerodynamic Decelerators (HIADs). At the beginning of 2014, a 6m HIAD inflatable structure with an integrated flexible thermal protection system (TPS) was subjected to a static load test series to verify the designs structural performance. The 6m HIAD structure was constructed in a stacked toroid configuration using nine inflatable torus segments composed of fiber reinforced thin films, which were joined together using adhesives and high strength textile woven structural straps to help distribute the loads throughout the inflatable structure. The 6m flexible TPS was constructed using multiple layers of high performance materials to protect the inflatable structure from heat loads that would be seen during atmospheric entry. To perform the static load test series, a custom test fixture was constructed. The fixture consisted of a structural tub rim with enough height to allow for displacement of the inflatable structure as loads were applied. The bottom of the tub rim had an airtight seal with the floor. The centerbody of the inflatable structure was attached to a pedestal mount as seen in Figure 1. Using an impermeable membrane seal draped over the test article, partial vacuum was pulled beneath the HIAD, resulting in a uniform static pressure load applied to the outer surface. During the test series an extensive amount of instrumentation was used to provide many data sets including: deformed shape, shoulder deflection, strap loads, cord loads, inflation pressures, and applied static load
Perspectives in hadron spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Richard, J.M. [Universite Joseph Fourier-IN2P3-CNRS, Lab. de Physique Subatomique et Cosmologie, 38 - Grenoble (France)
2005-07-01
A brief survey is presented of selected recent results on hadron spectroscopy and related theoretical studies. Among the new hadron states, some of them are good candidates for exotic structures: chiral partners of ground-states, hybrid mesons (quark, antiquark and constituent gluon), four-quark states, or meson-meson molecules.
DEFF Research Database (Denmark)
Jerke, G.; Pedersen, J.S.; Egelhaaf, S.U.
1997-01-01
We report a systematic investigation of the static structure factor S(q,c) of polymerlike reverse micelles formed by soybean lecithin and trace amounts of water in deuterated isooctane using small-angle neutron scattering and static light scattering. The experimental data for different concentrat......We report a systematic investigation of the static structure factor S(q,c) of polymerlike reverse micelles formed by soybean lecithin and trace amounts of water in deuterated isooctane using small-angle neutron scattering and static light scattering. The experimental data for different...
Electroproduction cross section of large-E bot hadrons at NLO and virtual photon structure function
International Nuclear Information System (INIS)
Fontannaz, M.
2004-01-01
We calculate higher order corrections to the resolved component of the electroproduction cross section of large- E bot hadrons. The parton distributions in the virtual photon are studied in detail and a NLO parametrization of the latter is proposed. The contribution of the resolved component to the forward production of large- E bot hadrons is calculated and its connection with the BFKL cross section is discussed. (orig.)
Exotic hadron and string junction model
International Nuclear Information System (INIS)
Imachi, Masahiro
1978-01-01
Hadron structure is investigated adopting string junction model as a realization of confinement. Besides exotic hadrons (M 4 , B 5 etc.), unconventional hadrons appear. A mass formula for these hadrons is proposed. New selection rule is introduced which requires the covalence of constituent line at hadron vertex. New duality appears due to the freedom of junction, especially in anti BB→anti BB reaction. A possible assignment of exotic and unconventional hadrons to recently observed narrow meson states is presented. (auth.)
Static/dynamic fluid-structure interaction analysis for 3-D rotary blade model
International Nuclear Information System (INIS)
Kim, Dong Hyun; Kim, Yu Sung; Kim, Dong Man; Park, Kang Kyun
2009-01-01
In this study, static/dynamic fluid-structure interaction analyses have been conducted for a 3D rotary blade model like a turbo-machinery or wind turbine blade. Advanced computational analysis system based on Computational Fluid Dynamics (CFD) and Computational Structural Dynamics (CSD) has been developed in order to investigate detailed dynamic responses of rotary type models. Fluid domains are modeled using the computational grid system with local grid deforming techniques. Reynolds-averaged Navier-Stokes equations with various turbulence model are solved for unsteady flow problems of the rotating blade model. Detailed static/dynamic responses and instantaneous pressure contours on the blade surfaces considering flow-separation effects are presented to show the multi-physical phenomenon of the rotating blades.
Montes-Perez, J; Cruz-Vera, A; Herrera, J N
2011-12-01
This work presents the full analytic expressions for the thermodynamic properties and the static structure factor for a hard sphere plus 1-Yukawa fluid within the mean spherical approximation. To obtain these properties of the fluid type Yukawa analytically it was necessary to solve an equation of fourth order for the scaling parameter on a large scale. The physical root of this equation was determined by imposing physical conditions. The results of this work are obtained from seminal papers of Blum and Høye. We show that is not necessary the use the series expansion to solve the equation for the scaling parameter. We applied our theoretical result to find the thermodynamic and the static structure factor for krypton. Our results are in good agreement with those obtained in an experimental form or by simulation using the Monte Carlo method.
Unraveling the Structure of Hadrons with Effective Field Theories of QCD
International Nuclear Information System (INIS)
Iain Stewart
2004-01-01
Effective Field theory is a powerful framework based on controlled expansions for problems with a natural separation of energy scales. This technique is particularly important for QCD, the theory of strong interactions, due to the vast diversity of phenomena that it describes. Stewart and collaborators have invented a new class of effective theories that can be used in processes with energetic hadrons. These Soft-Collinear Effective Theories provide a unified framework for describing hadronic processes which involve hard probes or the release of a large amount of energy. Many interesting issues about hadronic physics can be addressed with the soft-collinear effective theory. Examples include the size and shape of hadronic form factors, the universality of hadronic distribution functions for a plethora of processes, and the importance of subleading corrections at intermediate energy scales. Effective field theories allow these issues to be addressed using only the underlying symmetries and scales in QCD. Understanding these issues also has a direct impact on other areas of physics, such as on devising clean methods for the measurement of CP violation in the decay of B-mesons. Current progress on the soft-collinear effective theory and related methods is discussed in this report
Combined Differential and Static Pressure Sensor based on a Double-Bridged Structure
DEFF Research Database (Denmark)
Pedersen, Casper; Jespersen, S.T.; Krog, J.P.
2005-01-01
A combined differential and static silicon microelectromechanical system pressure sensor based on a double piezoresistive Wheatstone bridge structure is presented. The developed sensor has a conventional (inner) bridge on a micromachined diaphragm and a secondary (outer) bridge on the chip...... substrate. A novel approach is demonstrated with a combined measurement of outputs from the two bridges, which results in a combined deduction of both differential and static media pressure. Also following this new approach, a significant improvement in differential pressure sensor accuracy is achieved....... Output from the two bridges depends linearly on both differential and absolute (relative to atmospheric pressure) media pressure. Furthermore, the sensor stress distributions involved are studied by three-dimensional finite-element (FE) stress analysis. Furthermore, the FE analysis evaluates current...
Comparing of Normal Stress Distribution in Static and Dynamic Soil-Structure Interaction Analyses
International Nuclear Information System (INIS)
Kholdebarin, Alireza; Massumi, Ali; Davoodi, Mohammad; Tabatabaiefar, Hamid Reza
2008-01-01
It is important to consider the vertical component of earthquake loading and inertia force in soil-structure interaction analyses. In most circumstances, design engineers are primarily concerned about the analysis of behavior of foundations subjected to earthquake-induced forces transmitted from the bedrock. In this research, a single rigid foundation with designated geometrical parameters located on sandy-clay soil has been modeled in FLAC software with Finite Different Method and subjected to three different vertical components of earthquake records. In these cases, it is important to evaluate effect of footing on underlying soil and to consider normal stress in soil with and without footing. The distribution of normal stress under the footing in static and dynamic states has been studied and compared. This Comparison indicated that, increasing in normal stress under the footing caused by vertical component of ground excitations, has decreased dynamic vertical settlement in comparison with static state
Static structure of superionic conducting glass of Ag-Ge-Se system
Energy Technology Data Exchange (ETDEWEB)
Suenaga, R; Nakashima, S; Tahara, S; Takeda, S [Graduate School of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Fukuoka 810-8560 (Japan); Kawakita, Y [Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Fukuoka 810-8560 (Japan); Kohara, S [Japan Synchrotron Radiation Research Inst., 1-1-1 Kouto, Sayo-cho, Hyogo 679-5198 (Japan)], E-mail: takeda@rc.kyushu-u.ac.jp
2008-02-15
Superionic conducting glasses are the important materials as solid electrolytes. Amorphous Ag-Ge-Se system is well known to exhibit the superionic conducting behavior where silver ions easily migrate into the mixed structure of Ag{sub 2}Se and Ge-Se chalcogenide glass. It will be good material to study how the superionic conducting region distributes in the glassy network, and whether the conducting paths extends to the entire of the material, or the localized and limited area in an isolated region. In this paper, we will present the results of the static structure of Ag-Ge-Se system by high-energy X-ray diffraction measurements.
International Nuclear Information System (INIS)
Berenguer, J.
2014-01-01
The assembly of a mechanical structure used for a semi-digital hadronic calorimeter prototype, conceived and developed by the SDHCAL group within the CALICE collaboration, is presented in this note. CALICE is an international R and D collaboration dedicated to the development of calorimeters for future linear collider experiments. The design, assembly and quality control of this mechanical structure were entirely carried out at CIEMAT. This document contains a description of the prototype and its detectors, focusing on the design and assembly of the mechanical structure, which acts as well as the calorimeter absorber.. (Author)
Hadron properties in nuclear matter and the phase structure of a skyrmionic system
International Nuclear Information System (INIS)
Yakhshiev, Ulugbek; Kim, Hyun-Chul
2010-01-01
Hadron properties and their interactions in a nuclear environment are considered in the framework of the in-medium modified Skyrme model. Furthermore, the influence of the medium modifications of the single hadron properties and their interactions to the stability of the whole system is considered by using the variational method of the Hartree-Fock type. In addition to previous studies, we discuss the possible in-medium modifications of the stabilizing Skyrme term which can be related to the modifications of vector meson properties in a nuclear environment. (author)
A Scrutiny of the Equivalent Static Lateral Load Method of Design for Multistory Masonry Structures
International Nuclear Information System (INIS)
Touqan, A. R.; Helou, S. H.
2008-01-01
Building structures with a soft storey are gaining widespread popularity in urban areas due to the scarcity of land and due to the pressing need for wide open spaces at the entrance level. In earthquake prone zones dynamic analysis based on the Equivalent Static Lateral Load method is attractive to the novice and the design codes leave the choice of the analysis procedure up to the discretion of the designer. The following is a comparison of the said method with the more elaborate Response Spectrum Method of analysis as they apply to a repertoire of different structural models. The results clearly show that the former provides similar results of response in structures with gradual change in storey stiffness; while it is over conservative for a bare frame structure. It is however less conservative for structures with a soft storey
SAP-4, Static and Dynamic Linear System Stress Analysis for Various Structures
International Nuclear Information System (INIS)
Zawadzki, S.
1984-01-01
1 - Description of problem or function: SAP4 is a structural analysis program for determining the static and dynamic response of linear systems. The structural systems to be analyzed may be composed of combinations of a number of different structural elements. Currently the program contains the following element types - (a) three-dimensional truss element, (b) three-dimensional beam element, (c) plane stress and plane strain element, (d) two-dimensional axisymmetric solid, (e) three-dimensional solid, (f) variable-number nodes thick shell and three-dimensional element, (g) thin-plate or thin-shell element, (h) boundary element, and (i) pipe element (tangent and bend). 2 - Method of solution: The formation of the structure matrices is carried out in the same way in a static or dynamic analysis. The static analysis is continued by solving the equations of equilibrium followed by the computation of element stresses. In a dynamic analysis the choice is between frequency calculations only, frequency calculations followed by response history analysis, frequency calculations followed by response spectrum analysis, or response history analysis by direct integration. To obtain the frequencies and vibration mode shapes, solution routines are used which calculate the required eigenvalues and eigenvectors directly without a transformation of the structure stiffness matrix and mass matrix to a reduced form. To perform the direct integration an unconditionally stable scheme is used, which also operates on the original structure stiffness matrix and mass matrix. In this manner the program operation and input data required for a dynamic analysis are simple extensions of those needed for a static analysis. 3 - Restrictions on the complexity of the problem: The capacity of the program depends mainly on the total number of nodal points in the system, the number of eigenvalues needed in the dynamic analysis, and the computer used. There is practically no restriction on the number of
Wang, Wei
2018-05-11
Android platform has dominated the Operating System of mobile devices. However, the dramatic increase of Android malicious applications (malapps) has caused serious software failures to Android system and posed a great threat to users. The effective detection of Android malapps has thus become an emerging yet crucial issue. Characterizing the behaviors of Android applications (apps) is essential to detecting malapps. Most existing work on detecting Android malapps was mainly based on string static features such as permissions and API usage extracted from apps. There also exists work on the detection of Android malapps with structural features, such as Control Flow Graph (CFG) and Data Flow Graph (DFG). As Android malapps have become increasingly polymorphic and sophisticated, using only one type of static features may result in false negatives. In this work, we propose DroidEnsemble that takes advantages of both string features and structural features to systematically and comprehensively characterize the static behaviors of Android apps and thus build a more accurate detection model for the detection of Android malapps. We extract each app’s string features, including permissions, hardware features, filter intents, restricted API calls, used permissions, code patterns, as well as structural features like function call graph. We then use three machine learning algorithms, namely, Support Vector Machine (SVM), k-Nearest Neighbor (kNN) and Random Forest (RF), to evaluate the performance of these two types of features and of their ensemble. In the experiments, We evaluate our methods and models with 1386 benign apps and 1296 malapps. Extensive experimental results demonstrate the effectiveness of DroidEnsemble. It achieves the detection accuracy as 95.8% with only string features and as 90.68% with only structural features. DroidEnsemble reaches the detection accuracy as 98.4% with the ensemble of both types of features, reducing 9 false positives and 12 false
Venkatakrishnan, Balasubramanian; Palii, Miorel-Lucian; Agbandje-McKenna, Mavis; McKenna, Robert
2012-03-01
The Protein Data Bank (PDB) contains over 71,000 structures. Extensively studied proteins have hundreds of submissions available, including mutations, different complexes, and space groups, allowing for application of data-mining algorithms to analyze an array of static structures and gain insight about a protein's structural variation and possibly its dynamics. This investigation is a case study of HIV protease (PR) using in-house algorithms for data mining and structure superposition through generalized formulæ that account for multiple conformations and fractional occupancies. Temperature factors (B-factors) are compared with spatial displacement from the mean structure over the entire study set and separately over bound and ligand-free structures, to assess the significance of structural deviation in a statistical context. Space group differences are also examined.
The hidden symmetries and their algebraic structure of the static axially symmetric SDYM fields
International Nuclear Information System (INIS)
Hao Sanru
1993-01-01
A new explicit transformation about the static axially symmetric self-dual Yang-Mills (SDYM) fields is presented. The theory has proved that the new transformation is a symmetric one. For the two kinds of the Lie algebraic generators of the Lie group SL (N. R) /SO (N), the corresponding transformations are given. By making use of the Yang-Baxter equality and their square brackets, the loop and conformal algebraic structures of the symmetric transformations for the basic fields have been obtained. All the results obtained can be directly generalized to the other models
Electronic structure and static dipole polarizability of C60-C240
International Nuclear Information System (INIS)
Zope, Rajendra R
2008-01-01
The electronic structure of C 60 -C 240 and its first-order response to a static electric field is studied by an all-electron density functional theory calculation using large polarized Gaussian basis sets. Our results show that the outer C 240 shell almost completely shields the inner C 60 as inferred from the practically identical values of dipole polarizability of the C 60 -C 240 onion (449 A 3 ) and that of the isolated C 240 fullerene (441 A 3 ). The C 60 -C 240 is thus a near-perfect Faraday cage
Minute, Stephen A.
2013-01-01
Mr. Christopher Miller with the Kennedy Space Center (KSC) NASA Safety & Mission Assurance (S&MA) office requested the NASA Engineering and Safety Center's (NESC) technical support on March 15, 2012, to review and make recommendations on the structural analysis being performed for the Orbiter Atlantis static display at the KSC Visitor Center. The principal focus of the assessment was to review the engineering firm's structural analysis for lifting and aligning the orbiter and its static display configuration
Dikshit, Vishwesh; Nagalingam, Arun Prasanth; Yap, Yee Ling; Sing, Swee Leong; Yeong, Wai Yee; Wei, Jun
2017-01-01
The objective of this investigation was to determine the quasi-static indentation response and failure mode in three-dimensional (3D) printed trapezoidal core structures, and to characterize the energy absorbed by the structures. In this work, the trapezoidal sandwich structure was designed in the following two ways. Firstly, the trapezoidal core along with its facesheet was 3D printed as a single element comprising a single material for both core and facesheet (type A); Secondly, the trapezoidal core along with facesheet was 3D printed, but with variation in facesheet materials (type B). Quasi-static indentation was carried out using three different indenters, namely standard hemispherical, conical, and flat indenters. Acoustic emission (AE) technique was used to capture brittle cracking in the specimens during indentation. The major failure modes were found to be brittle failure and quasi-brittle fractures. The measured indentation energy was at a maximum when using a conical indenter at 9.40 J and 9.66 J and was at a minimum when using a hemispherical indenter at 6.87 J and 8.82 J for type A and type B series specimens respectively. The observed maximum indenter displacements at failure were the effect of material variations and composite configurations in the facesheet. PMID:28772649
Technical study on semi-object emulation of structural statics problem
International Nuclear Information System (INIS)
Mo Jun; Shi Pingan; Liu Xingfu; Liu Zhiyong; Fu Chunyu
2002-01-01
Structural strength analysis depends mainly on finite element method and experiments. For complex structural system, a rather large error can be caused by some uncertain factors, such as load distributions, boundary conditions and constitutive relations in numerical analysis. At the same time, owing to the limitation of measuring and testing techniques, the strength and stiffness of key components can not be estimated by using the limited test data. To simulate stresses accurately under complex static environment, improve man-machine interactive system, and make the best use of fore- and post-processing function in graphic data processing, the authors combine numerical analysis with experimental technique and have developed the semi-object emulation technique to analyze the nonlinear problem of structure statics. The modern optical measuring techniques and image processing techniques are firstly used for the method to acquire displacement data of the vessel surface, and the data are used for the boundary condition to determine the geometrical size of disfigurement in the wall of vessel and the stress level. The experimental verification of a given test model show that these adverse problem can be solved by using semi-object emulation technology
The Static and Molecular Structure of Barium Dibromide: A Theoretical Study
International Nuclear Information System (INIS)
Guerbuez, H.
2004-01-01
The geometry of barium dibromide was first determined by electron diffraction by Akishin and Spiridov. That study concluded that the molecule is linear, but recent modern electron diffraction and quantum chemical studies of BaBr 2 indicated that its equilibrium geometry is bent. The geometrical parameters, namely, bond lengths and bond angles of barium dibromide were calculated from different levels of computation and experimentally. In this work we have calculated the molecular structure of the BaCl 2 using the Interionic Force model. On the other hand, we have calculated the interionic potentials with two different rigid ion model potentials (RIM) which one is the Vashista-Rahman (VR) semi-empirical potential and second one is the RIM potential with parametrization of Tatlipinar. These two model potential are compared with each other by reproducing the experimental static structure. The structure calculations have been performed by solving numerically the hypernetted chain approximate of liquids
Barate, R; Ghez, P; Goy, C; Lees, J P; Merle, E; Minard, M N; Pietrzyk, B; Alemany, R; Casado, M P; Chmeissani, M; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Pacheco, A; Park, I C; Riu, I; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Becker, U; Boix, G; Cattaneo, M; Cerutti, F; Ciulli, V; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Halley, A W; Hansen, J B; Harvey, J; Janot, P; Jost, B; Lehraus, Ivan; Leroy, O; Mato, P; Minten, Adolf G; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Rousseau, D; Schlatter, W D; Schmitt, M; Schneider, O; Spagnolo, P; Tejessy, W; Teubert, F; Tomalin, I R; Tournefier, E; Wright, A E; Ajaltouni, Ziad J; Badaud, F; Chazelle, G; Deschamps, O; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Rougé, A; Rumpf, M; Swynghedauw, M; Verderi, M; Videau, H L; Focardi, E; Parrini, G; Zachariadou, K; Cavanaugh, R J; Corden, M; Georgiopoulos, C H; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Lynch, J G; Negus, P; O'Shea, V; Raine, C; Teixeira-Dias, P; Thompson, A S; Buchmüller, O L; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bowdery, C K; Buck, P G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Robertson, N A; Williams, M I; Giehl, I; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Wachsmuth, H W; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Carr, J; Coyle, P; Etienne, F; Motsch, F; Payre, P; Talby, M; Thulasidas, M; Aleppo, M; Antonelli, M; Ragusa, F; Büscher, V; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Mannert, C; Männer, W; Moser, H G; Schael, S; Settles, Ronald; Seywerd, H C J; Stenzel, H; Wiedenmann, W; Wolf, G; Azzurri, P; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Le Diberder, F R; Lefrançois, J; Lutz, A M; Schune, M H; Veillet, J J; Videau, I; Zerwas, D; Bagliesi, G; Bettarini, S; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Ferrante, I; Foà, L; Giassi, A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sguazzoni, G; Tenchini, Roberto; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Cowan, G D; Green, M G; Medcalf, T; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S L; Combley, F; Kelly, M S; Lehto, M H; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Grupen, Claus; Prange, G; Giannini, G; Gobbo, B; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Charles, E; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Greening, T C; Hayes, O J; Hu, H; Jin, S; McNamara, P A; Nachtman, J M; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu Sau Lan; Wu, X; Zobernig, G
1999-01-01
Inclusive gamma * gamma interactions to hadronic final states where one scattered electron or positron is detected in the electromagnetic calorimeters have been studied in the LEP 1 data taken by ALEPH from 1991 to 1995. The event sample has been used to measure the hadronic structure function of the photon F/sub 2//sup gamma / in three bins with of 9.9, 20.7 and 284 GeV/sup 2/. (31 refs).
Characteristics of cell-structure hadron calorimeter on the base of plastic scintillator mouldings
International Nuclear Information System (INIS)
Bityukov, S.I.; Semenov, V.K.; Yablokov, A.P.
1987-01-01
Design features are considered and the results of measurements of the characteristics of a full-scale hadron calorimeter with 1 m 2 aperture, about 8 t in weight and the 10x10 cm cell are presented. The polysterene scintillator made by the moulding method has been used in the calorimeter. The calorimeter is aimed at measuring neutron energy in experiments with hyperon beams. The calorimeter possesses a good spatial (14 mm at 37.5 GeV energy) and energy (0.7/√E) resolution and permits to detect both charged and neutral hadrons in the wide energy range. The calorimeter is easily producible and reliable in operation. The calorimetr design permits to assemble detectors of a large aperture by joining of some modules with 1x1 m cross section
International Nuclear Information System (INIS)
Bugrij, G.; Jenkovsky, L.; Martynov, E.
1994-01-01
These Proceedings contain the contributions to the Workshop HADRONS-94,held in Uzhgorod between September 7-11,1994. They covers the topics: - elastic and diffractive scattering of hadrons and nuclei; -small-x and spin physics; - meson and baryon spectroscopy; - dual and string models; - collective properties of the strongly interacting matter
Energy Technology Data Exchange (ETDEWEB)
Bugrij, G; Jenkovsky, L; Martynov, E [eds.
1994-12-31
These Proceedings contain the contributions to the Workshop HADRONS-94,held in Uzhgorod between September 7-11,1994. They covers the topics: - elastic and diffractive scattering of hadrons and nuclei; -small-x and spin physics; - meson and baryon spectroscopy; - dual and string models; - collective properties of the strongly interacting matter.
Heavy quarks and strong binding: A field theory of hadron structure
International Nuclear Information System (INIS)
Bardeen, W.A.; Chanowitz, M.S.; Drell, S.D.; Weinstein, M.; Yan, T.
1975-01-01
We investigate in canonical field theory the possibility that quarks may exist in isolation as very heavy particles, M/sub quark/) very-much-greater-than 1 GeV, yet form strongly bound hadronic states, M/sub hadron/) approx. 1 GeV. In a model with spin-1/2 quarks coupled to scalar gluons we find that a mechanism exists for the formation of bound states which are much lighter than the free constituents. Following Nambu, we introduce a color interaction mediated by gauge vector mesons to guarantee that all states with nonvanishing triality have masses much larger than 1 GeV. The possibility of such a solution to a stronly coupled field theory is exhibited by a calculation employing the variational principle in tree approximation. This procedure reduces the field-theoretical problem to a set of coupled differential equations for classical fields which are just the free parameters of the variational state. A striking property of the solution is that the quark wave function is confined to a thin shell at the surface of the hadronic bound state. Though the quantum corrections to this procedure remain to be investigated systematically, we explore some of the phenomenological implications of the trial wave functions so obtained. In particular, we exhibit the low-lying meson and baryon multiplets of SU(6); their magnetic moments, charge radii, and radiative decays, and the axial charge of the baryons. States of nonvanishing momenta are constructed and the softness of the hadron shell to deformations in scattering processes is discussed qualitatively along with the implications for deep-inelastic electron scattering and dual resonance models
A Feynman-Hellmann approach to the spin structure of hadrons
Energy Technology Data Exchange (ETDEWEB)
Chambers, A.J. [Adelaide Univ., SA (Australia). CSSM, Dept. of Physics; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe (Japan); Collaboration: CSSM and QCDSF/UKQCD Collaborations; and others
2014-05-15
We perform a N{sub f}=2+1 lattice QCD simulation to determine the quark spin fractions of hadrons using the Feynman-Hellmann theorem. By introducing an external spin operator to the fermion action, the matrix elements relevant for quark spin fractions are extracted from the linear response of the hadron energies. Simulations indicate that the Feynman-Hellmann method offers statistical precision that is comparable to the standard three-point function approach, with the added benefit that it is less susceptible to excited state contamination. This suggests that the Feynman-Hellmann technique offers a promising alternative for calculations of quark line disconnected contributions to hadronic matrix elements. At the SU(3)-flavour symmetry point, we find that the connected quark spin fractions are universally in the range 55-70% for vector mesons and octet and decuplet baryons. There is an indication that the amount of spin suppression is quite sensitive to the strength of SU(3) breaking.
Hadronization in nuclear matter
International Nuclear Information System (INIS)
Anton, G.; Blok, H.P.; Boudard, A.; Kopeliovich, B.
1993-01-01
The investigation of the space time structure of quark propagation and hadronization is proposed by studying particle production in deep-inelastic scattering of electrons from nucleons and nuclei with high statistics. A 15 to 30 GeV electron beam impinging on targets of hydrogen, deuterium, helium, carbon and lead is planned to be used and the final state hadrons are to be detected in a large solid angle device. (authors). 48 refs., 13 figs., 4 tabs
International Nuclear Information System (INIS)
Greenberg, O.W.; Nelson, C.A.
1977-01-01
The evidence for a three-valued 'color' degree of freedom in hadron physics is reviewed. The structure of color models is discussed. Consequences of color models for elementary particle physics are discussed, including saturation properties of hadronic states, π 0 →2γ and related decays, leptoproduction, and lepton pair annihilation. Signatures are given which distinguish theories with isolated colored particles from those in which color is permanently bound. (Auth.)
International Nuclear Information System (INIS)
Bhatnagar, Shashank; Li, Shiyuan
2009-01-01
We employ the framework of Bethe–Salpeter equation under Covariant Instantaneous Ansatz to study the leptonic decays of pseudoscalar mesons. The Dirac structure of hadron-quark vertex function Γ is generalized to include various Dirac covariants besides γ5 from their complete set. The covariants are incorporated in accordance with a power counting rule, order-by-order in powers of the inverse of the meson mass. The decay constants are calculated with the incorporation of leading order covariants. Most of the results are dramatically improved. (author)
International Nuclear Information System (INIS)
Siegel, E.
1982-01-01
The generalized-disorder collective-boson mode-softening universality-principle (GDCBMSUP) for collective-boson mode dispersion in disordered systems (liquids, quantum liquids, glasses, powders, disordered magnets, plasmas...), a unified qualitative and semi-qualitative and semi-quantitative descriptive prescription for treating the properties of very differently disordered systems, is directly dependent upon a measurement (or calculation) of the static structure factor S(k) determined from a frequency average of the dynamic structure factor S(k,w), a multiple of the inelastic differential neutron scattering cross section d 2 sigma/dwdOMEGA. The prescription for this principle is given and, because of its universal applicability to disordered systems of any type with any type and/or degree of disorder, the neutron scattering determination of S(k) takes on renewed importance
Quasi-Static Single-Component Hybrid Simulation of a Composite Structure with Multi-Axis Control
DEFF Research Database (Denmark)
Høgh, J.; Waldbjørn, J.; Wittrup-Schmidt, J.
2015-01-01
This paper presents a quasi-static hybrid simulation performed on a single component structure. Hybrid simulation is a substructural technique, where a structure is divided into two sections: a numerical section of the main structure and a physical experiment of the remainder. In previous cases...
International Nuclear Information System (INIS)
Martinez, M; Rocha, B; Li, M; Shi, G; Beltempo, A; Rutledge, R; Yanishevsky, M
2012-01-01
The National Research Council Canada (NRC) has worked on the development of structural health monitoring (SHM) test platforms for assessing the performance of sensor systems for load monitoring applications. The first SHM platform consists of a 5.5 m cantilever aluminum beam that provides an optimal scenario for evaluating the ability of a load monitoring system to measure bending, torsion and shear loads. The second SHM platform contains an added level of structural complexity, by consisting of aluminum skins with bonded/riveted stringers, typical of an aircraft lower wing structure. These two load monitoring platforms are well characterized and documented, providing loading conditions similar to those encountered during service. In this study, a micro-electro-mechanical system (MEMS) for acquiring data from triads of gyroscopes, accelerometers and magnetometers is described. The system was used to compute changes in angles at discrete stations along the platforms. The angles obtained from the MEMS were used to compute a second, third or fourth order degree polynomial surface from which displacements at every point could be computed. The use of a new Kalman filter was evaluated for angle estimation, from which displacements in the structure were computed. The outputs of the newly developed algorithms were then compared to the displacements obtained from the linear variable displacement transducers connected to the platforms. The displacement curves were subsequently post-processed either analytically, or with the help of a finite element model of the structure, to estimate strains and loads. The estimated strains were compared with baseline strain gauge instrumentation installed on the platforms. This new approach for load monitoring was able to provide accurate estimates of applied strains and shear loads. (paper)
Heavy flavour hadron spectroscopy: An overview
Indian Academy of Sciences (India)
2014-10-31
Oct 31, 2014 ... A comprehensive overview and some of the theoretical attempts towards understanding heavy flavour hadron spectroscopy are presented. Apart from the conventional quark structure (quark, antiquarks structure for the mesons and three-quarks structure of baryons) of hadrons, multiquark hadrons the ...
Confinement and hadron-hadron interactions by general relativistic methods
Recami, Erasmo
By postulating covariance of physical laws under global dilations, one can describe gravitational and strong interactions in a unified way. Namely, in terms of the new discrete dilational degree of freedom, our cosmos and hadrons can be regarded as finite, similar systems. And a discrete hierarchy of finite ``universes'' may be defined, which are governed by fields with strengths inversally proportional to their radii; in each universe an Equivalence Principle holds, so that the relevant field can be there geometrized. Scaled-down Einstein equations -with cosmological term- are assumed to hold inside hadrons (= strong micro-cosmoses); and they yield in a natural way classical confinement, as well as ``asymptotic freedom'', of the hadron constituents. In other words, the association of strong micro-universes of Friedmann type with hadrons (i.e., applying the methods of General Relativity to subnuclear particle physics) allows avoiding recourse to phenomenological models such as the Bag Model. Inside hadrons we have to deal with a tensorial field (= strong gravity), and hadron constituents are supposed to exchange spin-2 ``gluons''. Our approach allows us also to write down a tensorial, bi-scale field theory of hadron-hadron interactions, based on modified Einstein-type equations here proposed for strong interactions in our space. We obtain in particular: (i) the correct Yukawa behaviour of the strong scalar potential at the static limit and for r>~l fm; (ii) the value of hadron radii. As a byproduct, we derive a whole ``numerology'', connecting our gravitational cosmos with the strong micro-cosmoses (hadrons), such that it does imply no variation of G with the epoch. Finally, since a structute of the ``micro-universe'' type seems to be characteristic even of leptons, a hope for the future is including also weak interactions in our classical unification of the fundamental forces.
PPM-One: a static protein structure based chemical shift predictor
International Nuclear Information System (INIS)
Li, Dawei; Brüschweiler, Rafael
2015-01-01
We mined the most recent editions of the BioMagResDataBank and the protein data bank to parametrize a new empirical knowledge-based chemical shift predictor of protein backbone atoms using either a linear or an artificial neural network model. The resulting chemical shift predictor PPM-One accepts a single static 3D structure as input and emulates the effect of local protein dynamics via interatomic steric contacts. Furthermore, the chemical shift prediction was extended to most side-chain protons and it is found that the prediction accuracy is at a level allowing an independent assessment of stereospecific assignments. For a previously established set of test proteins some overall improvement was achieved over current top-performing chemical shift prediction programs
Narayanan, Ajit; Chen, Yi; Pang, Shaoning; Tao, Ban
2013-01-01
The continuous growth of malware presents a problem for internet computing due to increasingly sophisticated techniques for disguising malicious code through mutation and the time required to identify signatures for use by antiviral software systems (AVS). Malware modelling has focused primarily on semantics due to the intended actions and behaviours of viral and worm code. The aim of this paper is to evaluate a static structure approach to malware modelling using the growing malware signature databases now available. We show that, if malware signatures are represented as artificial protein sequences, it is possible to apply standard sequence alignment techniques in bioinformatics to improve accuracy of distinguishing between worm and virus signatures. Moreover, aligned signature sequences can be mined through traditional data mining techniques to extract metasignatures that help to distinguish between viral and worm signatures. All bioinformatics and data mining analysis were performed on publicly available tools and Weka.
STRUCTURAL CALCULATION OF AN EMPLACEMENT PALLET STATICALLY LOADED BY A WASTE PACKAGE
International Nuclear Information System (INIS)
S. Mastilovic
2000-01-01
The purpose of this calculation is to determine the structural response of the emplacement pallet (EP) subjected to static load from the mounted waste package (WP). The scope of this document is limited to reporting the calculation results in terms of stress intensity magnitudes. This calculation is associated with the waste emplacement systems design; calculations are performed by the Waste Package Design group. AP-3.12Q, Revision 0, ICN 0, Calculations, is used to perform the calculation and develop the document. The finite element solutions are performed by using the commercially available ANSYS Version (V) 5.4 finite element code. The results of these calculations are provided in terms of maximum stress intensity magnitudes
Electronic structure and static dipole polarizability of C{sub 60}-C{sub 240}
Energy Technology Data Exchange (ETDEWEB)
Zope, Rajendra R [Department of Physics, University of Texas at El Paso, El Paso, TX 79958 (United States)
2008-04-28
The electronic structure of C{sub 60}-C{sub 240} and its first-order response to a static electric field is studied by an all-electron density functional theory calculation using large polarized Gaussian basis sets. Our results show that the outer C{sub 240} shell almost completely shields the inner C{sub 60} as inferred from the practically identical values of dipole polarizability of the C{sub 60}-C{sub 240} onion (449 A{sup 3}) and that of the isolated C{sub 240} fullerene (441 A{sup 3}). The C{sub 60}-C{sub 240} is thus a near-perfect Faraday cage.
International Nuclear Information System (INIS)
Yoo, Nam-sun; Jung, Ui-Jin; Park, Gyung-Jin; Kim, Tai-Kyung
2014-01-01
An optimization method is proposed for the simultaneous design of structural and control systems using the equivalent static loads. In the past researches, the control parameters of such feedback gains are obtained to improve some performance in the steady-state. However, the actuators which have position and velocity feedback gains should be designed to exhibit a good performance in the time domain. In other words, the system analysis should be conducted for the transient-state in dynamic manner. In this research, a new equivalent static loads method is presented to treat the control variables as the design variables. The equivalent static loads (ESLs) set is defined as a static load set which generates the same displacement field as that from dynamic loads at a certain time. The calculated sets of ESLs are applied as multiple loading conditions in the optimization process. Several examples are solved to validate the proposed method
International Nuclear Information System (INIS)
Krueger, P.; Stucky, T.; Boewe, M.; Neuhaeuser, H.
1993-01-01
Quasi-static stress relaxation and dynamic internal friction measurements of stress induced reversible structural relaxation were performed on the amorphous alloy Fe 40 Ni 40 B 20 . The kinetics can be well described by a stretched exponential Kohlrausch-Williams-Watts quasi-static relaxation. The thermally activated part of the internal friction shows an Arrhenius temperature behaviour for a fixed vibration frequency and an inverse power frequency behaviour for a fixed temperature. The activation energies calculated from the Arrhenius equation and from the frequency shift method are significantly different. In order to explain this discrepancy the relation between the quasi-static and the dynamic descriptions of the reversible relaxation is reexamined. In particular it is shown that these two activation energies are connected by the Kohlrausch exponent of the quasi-static relaxation. (orig.)
Comparison of iron and tungsten absorber structures for an analog hadron calorimeter
International Nuclear Information System (INIS)
Guenter, Clemens
2015-05-01
Future electron-positron-collider experiments will require unprecedented jet-energy resolution to complete their physics programs. This can only be achieved with novel approaches to calorimetry. One of these novel approaches is the Particle Flow Algorithm, which uses the best suited sub-detector to measure the energy of the particles produced by the electronpositron collision. The CALICE Collaboration evaluates different read-out technologies for Particle Flow Calorimeters. This thesis describes the comparison of two different absorber materials, iron and tungsten, for the CALICE Analog Hadron Calorimeter. It is described how test-beam data, that have been recorded in the range from 2 GeV to 10 GeV with the Analog Hadron Calorimeter are calibrated, and how samples are selected containing showers from just one particle type. The data are then compared to simulations, and the remaining disagreement between data and simulation is discussed. The validated simulations are then used to decompose the showers into different fractions. These fractions are compared for the two absorber materials to understand the impact of the absorber material choice on the calorimeter performance.
Hadronization of quark-diquark model for nucleon structure and nuclear force by path integral
International Nuclear Information System (INIS)
Nagata, Keitaro
2003-01-01
One of the central issues of the hadron physics is how to interpret the properties and the origin of nuclear force. Nuclear force is in principle the manifestation of dynamics of quarks and gluons but no trial has been successful yet in describing the nuclear force by using QCD, the fundamental theory of the strong interactions. Phenomenon related to the chiral symmetry and the spontaneous breaking of the chiral symmetry is one of the important phenomena for the understanding of hadron physics. Nambu-Jona-Lasinio (NJL) model is one of the quark system models to explain the phenomena concerning the chiral symmetry. Although the method to deduce the Lagrangian describing mesons by applying the path integral to NJL model has been well known as the bosonization, it has been difficult to extend it to baryons because baryons are three-body system. In this paper, a method is reported to deduce Lagrangian which describes baryon-meson from quark-diquark Lagrangian by assuming that baryons are the bound states of quark and diquark. (S. Funahashi)
Quantum chromodynamics and hadron jets
International Nuclear Information System (INIS)
Dokshitser, Y.L.; Dyakonov, D.I.
1979-07-01
These lectures are devoted to the description of the various properties of hard scattering processes with the participation of hadrons in the framework of Quantum Chromodynamics. We discuss in detail the validity and region of applicability of perturbation theory applied to hadron processes. Particular attention is paid to the question of the structure of quark and gluon jets produced in hard processes (as an example, e + e - annihilation into hadrons). In addition to giving a pedagogical review, we also present new results. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Hicks, R.G.
1978-01-01
An experiment was performed to study muon-proton scattering at an incident energy of 225 GeV and a total effective flux of 4.3 x 10/sup 10/ muons. This experiment is able to detect charged particles in coincidence with the scattered muon in the forward hemisphere, and results are reported for the neutral strange particles K/sub s//sup 0/ and ..lambda../sup 0/ decaying into two charged particles. Within experimental limits the masses and lifetimes of these particles are consistent with previous measurements. The distribution of hadrons produced in muon scattering is determined, measuring momentum components parallel and transverse to the virtual photon direction, and these distributions are compared to other high energy experiments involving the scattering of pions, protons, and neutrinos from protons. Structure functions for hadron production and particle ratios are calculated. No azimuthal dependence is observed, and lambda production does not appear to be polarized. The physical significance of the results is discussed within the framework of the quark-parton model. 29 references.
The “ductility exhaustion” method for static strength assessment of fusion structures
Energy Technology Data Exchange (ETDEWEB)
Thompson, Vaughan, E-mail: vaughan.thompson@ccfe.ac.uk; Vizvary, Zsolt
2015-10-15
Graphical abstract: - Highlights: • Reduced conservatism and more complex geometry. • Assessment process simplified. • Gives insight into real material behaviour – virtual proof test. • Leads onto structural failure modelling. • Ductility exhaustion and global plastic collapse structural assessment. - Abstract: The traditional method for static strength assessment of structures uses elastic stresses computed along critical ligaments and then divided into categories depending on their nature e.g. bending/membrane and primary/secondary. More recently, highly realistic plastic simulations are possible using FE (finite elements) which offer useful advantages over the traditional approach including (a) more accurate modelling of complex geometries, (b) a more straightforward assessment process and (c) a less conservative approach. The plastic analysis must consider both global and local effects, and the paper looks in detail at the “ductility exhaustion” method for the latter. Simple test cases show how the method can be applied in both the Abaqus and ANSYS FE Codes and for the case of a JET beryllium tile, the method has improved reserve factors for disruption loads considerably to the point where the lower operating temperature can be safely lowered from 200 °C to 100 °C where the low ductility of beryllium is an issue.
Statistical modeling of static strengths of nuclear graphites with relevance to structural design
International Nuclear Information System (INIS)
Arai, Taketoshi
1992-02-01
Use of graphite materials for structural members poses a problem as to how to take into account of statistical properties of static strength, especially tensile fracture stresses, in component structural design. The present study concerns comprehensive examinations on statistical data base and modelings on nuclear graphites. First, the report provides individual samples and their analyses on strengths of IG-110 and PGX graphites for HTTR components. Those statistical characteristics on other HTGR graphites are also exemplified from the literature. Most of statistical distributions of individual samples are found to be approximately normal. The goodness of fit to normal distributions is more satisfactory with larger sample sizes. Molded and extruded graphites, however, possess a variety of statistical properties depending of samples from different with-in-log locations and/or different orientations. Second, the previous statistical models including the Weibull theory are assessed from the viewpoint of applicability to design procedures. This leads to a conclusion that the Weibull theory and its modified ones are satisfactory only for limited parts of tensile fracture behavior. They are not consistent for whole observations. Only normal statistics are justifiable as practical approaches to discuss specified minimum ultimate strengths as statistical confidence limits for individual samples. Third, the assessment of various statistical models emphasizes the need to develop advanced analytical ones which should involve modeling of microstructural features of actual graphite materials. Improvements of other structural design methodologies are also presented. (author)
Latest HERMES results on transverse spin effects in hadron structure and formation
International Nuclear Information System (INIS)
Pappalardo, L.L.
2008-01-01
Transverse target single-spin asymmetries in semi-inclusive deep inelastic scattering allow to study the so-called Collins and Sivers mechanisms. The first one connects the poorly known fundamental transversity distribution function, describing the transverse spin-polarization of quarks in a transversely polarized proton, to the Collins fragmentation function, describing spin-orbit correlations in the hadron formation process. The second one is sensitive to the Sivers function, which correlates the intrinsic transverse momentum of quarks with the proton's spin orientation and is related to the orbital angular momentum of quarks. Preliminary results on azimuthal single target-spin asymmetries in semi-inclusive electro-production of pions and kaons at the HERMES experiment are presented. The full data set collected with a transversely polarized hydrogen target was analyzed providing the HERMES most precise results on the Collins and Sivers azimuthal moments. (orig.)
The static structure factor of liquid 4He: some new aspects
International Nuclear Information System (INIS)
Khalil, K.Y.
1986-08-01
The thesis is concerned with three complementary problems. The first deals with a new interpretation of the elusive nature of the roton. This is motivated by the observation that the 'rotonic' minimum in the dispersion curve, which is intimately related to the principal peak of the static structure factor, is a common feature not only for He II but also for He I and almost all other condensed systems. The second problem concerns the precise asymptotic behaviour of the pair correlation function for liquid sup 4 He, whose Fourier transform is essentially the long-wavelength liquid structure factor. The third problem deals with the implications of this new formulation as related to Bose-Einstein condensation and superfluidity, as well as to other physical properties of the system. The thesis concludes with a partial list of open problems and with two possible extensions, including a complete development of an exceedingly simple method for determining the second virial coefficient of the sup 4 He gas over a wide temperature range. 122 refs., 2 figs., 5 tabs. (A.M.H)
Identifying Multiquark Hadrons from Heavy Ion Collisions
International Nuclear Information System (INIS)
Cho, Sungtae; Furumoto, Takenori; Yazaki, Koichi; Hyodo, Tetsuo; Jido, Daisuke; Ohnishi, Akira; Ko, Che Ming; Lee, Su Houng; Nielsen, Marina; Sekihara, Takayasu; Yasui, Shigehiro
2011-01-01
Identifying hadronic molecular states and/or hadrons with multiquark components either with or without exotic quantum numbers is a long-standing challenge in hadronic physics. We suggest that studying the production of these hadrons in relativistic heavy ion collisions offers a promising resolution to this problem as yields of exotic hadrons are expected to be strongly affected by their structures. Using the coalescence model for hadron production, we find that, compared to the case of a nonexotic hadron with normal quark numbers, the yield of an exotic hadron is typically an order of magnitude smaller when it is a compact multiquark state and a factor of 2 or more larger when it is a loosely bound hadronic molecule. We further find that some of the newly proposed heavy exotic states could be produced and realistically measured in these experiments.
Effect of stress level on static young's modulus of certain structural materials
Energy Technology Data Exchange (ETDEWEB)
Vojtenko, A.F.; Skripnik, Yu.D.; Solov' eva, N.G.; Nadezhdin, G.N. (AN Ukrainskoj SSR, Kiev. Inst. Problem Prochnosti)
1982-11-01
Certain steels, titanium and aluminium alloys have been studied for their dynamic and static Young moduli. It is shown that a stress rise in materials to the level of microplastic strain realization results in a significant reduction of the static modulus of elasticity in the materials studied.
Effect of stress level on static young's modulus of certain structural materials
International Nuclear Information System (INIS)
Vojtenko, A.F.; Skripnik, Yu.D.; Solov'eva, N.G.; Nadezhdin, G.N.
1982-01-01
Certain steels, titanium and aluminium alloys have been studied for their dynamic and static Young moduli. It is shown that a stress rise in materials to the level of microplastic strain realization results in a significant reduction of the static modulus of elasticity in the materials studied
International Nuclear Information System (INIS)
Close, F.E.
1987-09-01
The standard theory of colour forces (Quantum Chromodynamics) suggests that in addition to the familiar hadrons made of quarks, there should exist new states where coloured gluons play an essential dynamical role. The author reviews the theoretical predictions for the properties of these ''glueballs'' and of states containing resonating quarks and gluons. Attempts are made to highlight those features which are common to several models in the literature. Experimental candidates are confronted with the models. No clear cut signal for a gluonic hadron yet exists; consequently what future data are required to determine the constituency of some popular candidates is considered. (author)
Directory of Open Access Journals (Sweden)
Kołakowski Zbigniew
2016-06-01
Full Text Available A review of papers that investigate the static and dynamic coupled buckling and post-buckling behaviour of thin-walled structures is carried out. The problem of static coupled buckling is sufficiently well-recognized. The analysis of dynamic interactive buckling is limited in practice to columns, single plates and shells. The applications of finite element method (FEM or/and analytical-numerical method (ANM to solve interaction buckling problems are on-going. In Poland, the team of scientists from the Department of Strength of Materials, Lodz University of Technology and co-workers developed the analytical-numerical method. This method allows to determine static buckling stresses, natural frequencies, coefficients of the equation describing the post-buckling equilibrium path and dynamic response of the plate structure subjected to compression load and/or bending moment. Using the dynamic buckling criteria, it is possible to determine the dynamic critical load. They presented a lot of interesting results for problems of the static and dynamic coupled buckling of thin-walled plate structures with complex shapes of cross-sections, including an interaction of component plates. The most important advantage of presented analytical-numerical method is that it enables to describe all buckling modes and the post-buckling behaviours of thin-walled columns made of different materials. Thin isotropic, orthotropic or laminate structures were considered.
New concept for nuclear force: implications for nuclear structure and hadronic processes
International Nuclear Information System (INIS)
Kukulin, V.I.
2005-01-01
Full text: A new concept for nuclear force is discussed. The concept is based on idea about production of the intermediate six-quark bag (dibaryon) dressed with meson fields main of which are π-, σ-, p-, and ω-fields. The whole approach has been strongly motivated by our previous detailed analysis of various inner contradictions and inconsistencies in the conventional meson-exchange (i.e. Yukawa like) mechanism of nuclear force. The new force model predicts inevitable strong attractive 3N-force of scalar nature originated from σ-exchange between the dressed dibaryon and third nucleon. This new 3N-force has been demonstrated earlier to result in, at least, a half the total binding energy in lightest nuclei and contribute strongly to all nuclear properties like r. m. s. charge radius, nucleon momentum distribution, new electromagnetic currents and leads, very likely, to new understanding of saturation properties in nuclear matter. In the talk many other implications of the suggested new force model in hadronic and nuclear physics will be discussed
Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Romeo, G.Cara; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; van Dalen, J.A.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Hu, Y.; Jin, B.N.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mangeol, D.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, Mohammad Azizur; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, Stefan; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schafer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D.J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobyov, A.A.; Wadhwa, M.; Wang, Q.; Wang, X.L.; Wang, Z.M.; Weber, M.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, An.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.; Zoller, M.
2004-01-01
In this Report, QCD results obtained from a study of hadronic event structure in high energy e^+e^- interactions with the L3 detector are presented. The operation of the LEP collider at many different collision energies from 91 GeV to 209 GeV offers a unique opportunity to test QCD by measuring the energy dependence of different observables. The main results concern the measurement of the strong coupling constant, \\alpha_s, from hadronic event shapes and the study of effects of soft gluon coherence through charged particle multiplicity and momentum distributions.
Directory of Open Access Journals (Sweden)
Yusuf ÖNER
2005-03-01
Full Text Available The friction loss of electrical machines is an important problem as like in other rotary machines. In addition, the bearings, where the friction losses occur, also require lubrication at periodic intervals and need to be maintained. In this study, to minimize the friction loss of electrical motor, two dimentional static magnetic analysis of radial magnetic bearing systems with different structures are performed and compared with each other; also, magnetic bearing system with four-pole is realized and applied to an induction motor. In simulation, the forces applied to the rotor of induction motor from designed magnetic bearing system are calculated in a computer by using FEMM software package. In application, when comparing designed magnetic bearing system with mechanical bearings up to the revolution of 350 rpm, it was observed that the loss of no-load operating condition of induction motor is decreased about 15 % with magnetic bearing system. In addition to this, mechanical noisy of the motor is also decreased considerably.
Pan, Peng; Wu, Shoujun; Wang, Haishen; Nie, Xin
2018-04-01
Earthquake investigations have illustrated that even code-compliant reinforced concrete frames may suffer from soft-story mechanism. This damage mode results in poor ductility and limited energy dissipation. Continuous components offer alternatives that may avoid such failures. A novel infilled rocking wall frame system is proposed that takes advantage of continuous component and rocking characteristics. Previous studies have investigated similar systems that combine a reinforced concrete frame and a wall with rocking behavior used. However, a large-scale experimental study of a reinforced concrete frame combined with a rocking wall has not been reported. In this study, a seismic performance evaluation of the newly proposed infilled rocking wall frame structure was conducted through quasi-static cyclic testing. Critical joints were designed and verified. Numerical models were established and calibrated to estimate frame shear forces. The results evaluation demonstrate that an infilled rocking wall frame can effectively avoid soft-story mechanisms. Capacity and initial stiffness are greatly improved and self-centering behavior is achieved with the help of the infilled rocking wall. Drift distribution becomes more uniform with height. Concrete cracks and damage occurs in desired areas. The infilled rocking wall frame offers a promising approach to achieving seismic resilience.
Directory of Open Access Journals (Sweden)
Ana Paula Pinto Pinheiro
Full Text Available ABSTRACT Wood is the best-known biological material used as a raw material since the dawn of mankind until present days. As a natural and renewable composite, its lifetime is limited by the degradation of its basic elements. This degradation can be caused by chemical reactions or by biological agents capable of accelerating the process of deterioration. In this work, the wear, thermal, and micro-structural characteristics, as also the bio-degradation behavior in static systems, of the wood species Brazilwood (Caesalpinia echinata were studied under laboratory conditions in order to use these woods in design. The results show that Brazilwood has a good visual performance after abrasion test, since it has not shown any representative roughness increase. In addition, Brazilwood has high level of crystallinity of, approximately, 68% and was almost insensitive to fungi attack, forming only 5.3 x 103 CFU/mL. Besides, its texture did not change due to exposure to water or sweat.
Assembly of the CMS hadronic calorimeter
Maximilien Brice
2004-01-01
The hadronic calorimeter is assembled on the end-cap of the CMS detector in the assembly hall. Hadronic calorimeters measure the energy of particles that interact via the strong force, called hadrons. The detectors are made in a sandwich-like structure where these scintillator tiles are placed between metal sheets.
Analysis of the Nonlinear Static and Dynamic Behavior of Offshore Structures
Alfosail, Feras
2015-01-01
Understanding static and dynamic nonlinear behavior of pipes and risers is crucial for the design aspects in offshore engineering fields. In this work, we examine two nonlinear problems in offshore engineering field: vortex Induced vibration
Rodriguez, G.; Scheid, R. E., Jr.
1986-01-01
This paper outlines methods for modeling, identification and estimation for static determination of flexible structures. The shape estimation schemes are based on structural models specified by (possibly interconnected) elliptic partial differential equations. The identification techniques provide approximate knowledge of parameters in elliptic systems. The techniques are based on the method of maximum-likelihood that finds parameter values such that the likelihood functional associated with the system model is maximized. The estimation methods are obtained by means of a function-space approach that seeks to obtain the conditional mean of the state given the data and a white noise characterization of model errors. The solutions are obtained in a batch-processing mode in which all the data is processed simultaneously. After methods for computing the optimal estimates are developed, an analysis of the second-order statistics of the estimates and of the related estimation error is conducted. In addition to outlining the above theoretical results, the paper presents typical flexible structure simulations illustrating performance of the shape determination methods.
Mallik, Samirnath
2016-01-01
High energy laboratories are performing experiments in heavy ion collisions to explore the structure of matter at high temperature and density. This elementary book explains the basic ideas involved in the theoretical analysis of these experimental data. It first develops two topics needed for this purpose, namely hadron interactions and thermal field theory. Chiral perturbation theory is developed to describe hadron interactions and thermal field theory is formulated in the real-time method. In particular, spectral form of thermal propagators is derived for fields of arbitrary spin and used to calculate loop integrals. These developments are then applied to find quark condensate and hadron parameters in medium, including dilepton production. Finally, the non-equilibrium method of statistical field theory to calculate transport coefficients is reviewed. With technical details explained in the text and appendices, this book should be accessible to researchers as well as graduate students interested in thermal ...
Energy Technology Data Exchange (ETDEWEB)
Pondrom, L.
1991-10-03
An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs.
International Nuclear Information System (INIS)
Pondrom, L.
1991-01-01
An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs
Spacetime structure of static solutions in Gauss-Bonnet gravity: Neutral case
International Nuclear Information System (INIS)
Torii, Takashi; Maeda, Hideki
2005-01-01
We study the spacetime structures of the static solutions in the n-dimensional Einstein-Gauss-Bonnet-Λ system systematically. We assume the Gauss-Bonnet coefficient α is non-negative and a cosmological constant is either positive, zero, or negative. The solutions have the (n-2)-dimensional Euclidean submanifold, which is the Einstein manifold with the curvature k=1, 0, and -1. We also assume 4α-tilde/l 2 ≤1, where l is the curvature radius, in order for the sourceless solution (M=0) to be defined. The general solutions are classified into plus and minus branches. The structures of the center, horizons, infinity, and the singular point depend on the parameters α, l 2 , k, M, and branches complicatedly so that a variety of global structures for the solutions are found. In our analysis, the M-tilde-r diagram is used, which makes our consideration clear and enables easy understanding by visual effects. In the plus branch, all the solutions have the same asymptotic structure at infinity as that in general relativity with a negative cosmological constant. For the negative-mass parameter, a new type of singularity called the branch singularity appears at nonzero finite radius r=r b >0. The divergent behavior around the singularity in Gauss-Bonnet gravity is milder than that around the central singularity in general relativity. There are three types of horizons: inner, black hole, and cosmological. In the k=1,0 cases, the plus-branch solutions do not have any horizon. In the k=-1 case, the radius of the horizon is restricted as r h h >√(2α-tilde)) in the plus (minus) branch. The black hole solution with zero or negative mass exists in the plus branch even for the zero or positive cosmological constant. There is also the extreme black hole solution with positive mass. We briefly discuss the effect of the Gauss-Bonnet corrections on black hole formation in a collider and the possibility of the violation of the third law of the black hole thermodynamics
International Nuclear Information System (INIS)
Kubo, K.-I.; Suzuki, K.; Nakajima, N.
2002-01-01
The spin polarizations of hadrons inclusively produced by pp, γp and νp collisions are studied by the quark rearrangement model. The present model is a phenomenological one based on the relativistic spin equations of motion and using the quark distribution functions in hadrons and photon. A general success of the model is demonstrated. We find usefulness of the present formulation for studying the dynamics producing spin asymmetry distributions and the statics determining signs and magnitudes of the spin polarization by reflecting the characteristic quark structure in hadrons. (author)
International Nuclear Information System (INIS)
Anon.
1986-01-01
The European Hadron Facility (EHF) is a project for particle and nuclear physics in the 1990s which would consist of a fast cycling high intensity proton synchrotron of about 30 GeV primary energy and providing a varied spectrum of intense high quality secondary beams (polarized protons, pions, muons, kaons, antiprotons, neutrinos). The physics case of this project has been studied over the last two years by a European group of particle and nuclear physicists (EHF Study Group), whilst the conceptual design for the accelerator complex was worked out (and is still being worked on) by an international group of machine experts (EHF Design Study Group). Both aspects have been discussed in recent years in a series of working parties, topical seminars, and workshops held in Freiburg, Trieste, Heidelberg, Karlsruhe, Les Rasses and Villigen. This long series of meetings culminated in the International Conference on a European Hadron Facility held in Mainz from 10-14 March
International Nuclear Information System (INIS)
Leonard, J.W.
1975-01-01
This work is concerned with the evaluation of a quasi-static method as applied to a swing check valve designed to provide emergency shut-off capability subsequent to a postulated break in a steam line. The impact analysis of swinging disk upon the valve seat is an asymmetric problem in dynamic elastoplasticity with potentially large displacements and strains resulting from the impact. To perform a quasi-static analysis for this component the disk and seat region of the valve was isolated from the piping system by special boundary elements and an elastic-plastic finite element model was generated assuming axisymmetric solid ring elements. An equivalent static axisymmetric incremental load system was used to approximate the nonsymmetric initial velocity of impact. Subsequent to the nonlinear incremental finite element analysis by a standard computer software package (MARC-CDC program), a special post-processing program was employed to calculate the incremental sum of external work due to the defined load system. Equating this external work to the initial kinetic energy of impact, parametric curves for displacements, stresses, and strains were obtained as functions of various levels of kinetic energy imparted to the valve at closure. To verify the conservative nature of the assumptions made in the quasi-static model, a comparison was made with a time-dependent, nonlinear, axisymmetric, elastic-plastic finite difference simulation. Another standard computer software package (PISCES-2DL) was used for this dynamic simulation. For a check-point value of initial impact kinetic energy, correlation between the quasi-static finite element and dynamic finite difference analyses is presented. Validations of the assumptions made in the quasi-static analysis and of the results obtained are discussed in detail
Bilki, Burak
2018-03-01
The Particle Flow Algorithms attempt to measure each particle in a hadronic jet individually, using the detector providing the best energy/momentum resolution. Therefore, the spatial segmentation of the calorimeter plays a crucial role. In this context, the CALICE Collaboration developed the Digital Hadron Calorimeter. The Digital Hadron Calorimeter uses Resistive Plate Chambers as active media and has a 1-bit resolution (digital) readout of 1 × 1 cm2 pads. The calorimeter was tested with steel and tungsten absorber structures, as well as with no absorber structure, at the Fermilab and CERN test beam facilities over several years. In addition to conventional calorimetric measurements, the Digital Hadron Calorimeter offers detailed measurements of event shapes, rigorous tests of simulation models and various tools for improved performance due to its very high spatial granularity. Here we report on the results from the analysis of pion and positron events. Results of comparisons with the Monte Carlo simulations are also discussed. The analysis demonstrates the unique utilization of detailed event topologies.
International Nuclear Information System (INIS)
Souto, J; Alemany, M M G; Gallego, L J; González, L E; González, D J
2013-01-01
We report an ab initio molecular dynamics study of the static, dynamic and electronic properties of the liquid Bi x Li 1−x alloy, which is a complex binary system with a marked tendency to heterocoordination. The calculated total static structure factors are in good agreement with the available experimental data. The partial dynamic structure factors exhibit side peaks indicative of propagating density fluctuations, and for some concentrations we have found a density fluctuation mode with phase velocity greater than the hydrodynamic sound velocity. We have also evaluated other dynamical properties such as the diffusion coefficients, the shear viscosity and the adiabatic sound velocity. The electronic density of states show that the liquid Bi x Li 1−x alloy has a metallic character, although with strong deviations from the free-electron parabolic curve. The results reported improve the understanding of binary liquid alloys with both fast and slow propagating collective modes. (paper)
Analysis of the Nonlinear Static and Dynamic Behavior of Offshore Structures
Alfosail, Feras
2015-07-01
Understanding static and dynamic nonlinear behavior of pipes and risers is crucial for the design aspects in offshore engineering fields. In this work, we examine two nonlinear problems in offshore engineering field: vortex Induced vibration of straight horizontal pipes, and boundary layer static solution of inclined risers. In the first study, we analyze the effect of the internal velocity of straight horizontal pipe and obtain the vortex induced vibration forces via coupling the pipe equation of motion with the recently modified Van Der Pol oscillator governing the lift coefficient. Our numerical results are obtained for two different pipe configurations: hinged-hinged, and clamped- clamped. The results show that the internal velocity reduces the vibration and the oscillation amplitudes. Also, it is shown that the clamped-clamped pipe configuration offers a wider range of internal velocities before buckling instability occurs. The results also demonstrate the effect of the end condition on the amplitudes of vibration. In the second study, we develop a boundary layer perturbation static solution to govern and simulate the static behavior of inclined risers. In the boundary layer analysis, we take in consideration the effects of the axial stretch, applied tension, and internal velocity. Our numerical simulation results show good agreement with the exact solutions for special cases. In addition, our developed method overcomes the mathematical and numerical limitations of the previous methods used before.
Large x Behaviour and the Non-Perturbative Structure of Hadronic Systems
Energy Technology Data Exchange (ETDEWEB)
Anthony W. Thomas
2005-02-01
While the traditional interest in structure functions has been the confirmation of the predictions of perturbative QCD, this data also contains a wealth of information on how QCD works in the infrared, or confinement, region. As the challenge of the strong force now turns to the study of QCD in the non-perturbative region, such information is extremely valuable.We outline some of the key issues for both nucleon and nuclear structure functions.
International Nuclear Information System (INIS)
Bluemlein, J.
1993-08-01
The possibilities to measure structure functions, to extract parton distributions, and to measure α s and Λ QCD in current and future high energy deep inelastic scattering experiments are reviewed. A comparison is given for experiments at HERA, an ep option at LEP xLHC, and a high energy neutrino experiment. (orig.)
International Nuclear Information System (INIS)
Bunce, G.
1984-01-01
Is all hadronic physics ultimately describable by QCD. Certainly, many disparate phenomena can be understood within the QCD framework. Also certainly, there are important questions which are open, both theoretically (little guidance, as yet) and experimentally, regarding confinement. Are there dibaryons, baryonium, glueballs. In addition, there are experimental results which at present do not have an explanation. This talk, after a short section on QCD successes and difficulties, will emphasize two experimental topics which have recent results - glueball spectroscopy and exclusive reactions at large momentum transfer. Both are experimentally accessible in the AGS/LAMPF II/AGS II/TRIUMF II/SIN II energy domain
Nuclei, hadrons, and elementary particles
International Nuclear Information System (INIS)
Bopp, F.W.
1989-01-01
This book is a short introduction to the physics of the nuclei, hadrons, and elementary particles for students of physics. Important facts and model imaginations on the structure, the decay, and the scattering of nuclei, the 'zoology' of the hadrons and basic facts of hadronic scattering processes, a short introduction to quantum electrodynamics and quantum chromodynamics and the most important processes of lepton and parton physics, as well as the current-current approach of weak interactions and the Glashow-Weinberg-Salam theory are presented. (orig.) With 153 figs., 10 tabs [de
Measurements of the structure of quark and gluon jets in hadronic Z decays
Barate, R; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Merle, E; Minard, M N; Nief, J Y; Pietrzyk, B; Alemany, R; Boix, G; Casado, M P; Chmeissani, M; Crespo, J M; Delfino, M C; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Becker, U; Bright-Thomas, P G; Casper, David William; Cattaneo, M; Ciulli, V; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Hansen, J B; Harvey, J; Janot, P; Jost, B; Lehraus, Ivan; Mato, P; Minten, Adolf G; Moneta, L; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rolandi, Luigi; Rousseau, D; Schlatter, W D; Schmitt, M; Schneider, O; Tejessy, W; Teubert, F; Tomalin, I R; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Badaud, F; Chazelle, G; Deschamps, O; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Cerutti, F; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Halley, A W; Lynch, J G; Negus, P; O'Shea, V; Raine, C; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, E; Buchmüller, O L; Dhamotharan, S; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Marinelli, N; Moutoussi, A; Nash, J; Sedgbeer, J K; Spagnolo, P; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Buck, P G; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Williams, M I; Giehl, I; Greene, A M; Hoffmann, C; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Bujosa, G; Carr, J; Coyle, P; Etienne, F; Leroy, O; Motsch, F; Payre, P; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Antonelli, M; Ragusa, F; Berlich, R; Blum, Walter; Büscher, V; Dietl, H; Ganis, G; Kroha, H; Lütjens, G; Mannert, C; Männer, W; Moser, H G; Schael, S; Settles, Ronald; Seywerd, H C J; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Schune, M H; Tournefier, E; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Boccali, T; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sciabà, A; Tenchini, Roberto; Tonelli, G; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Bryant, L M; Chambers, J T; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Brew, C A J; Cartwright, S L; Combley, F; Kelly, M S; Lehto, M H; Reeve, J; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Cowan, G D; Grupen, Claus; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Charles, E; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Greening, T C; Hayes, O J; Hu, H; Jin, S; McNamara, P A; Nachtman, J M; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu Sau Lan; Wu, X; Zobernig, G
2000-01-01
An experimental investigation of the structure of identified quark and gluon jets is presented. Observables related to both the global and internal structure of jets are measured; this allows for tests of QCD over a wide range of transverse momentum scales. The observables include distributions of jet-shape variables, the mean and standard deviation of the subjet multiplicity distribution and the fragmentation function for charged particles. The data are compared with predictions of perturbative QCD as well as QCD-based Monte Carlo models. In certain kinematic regions the measurements are sensitive mainly to perturbatively calculable effects, allowing for a test of QCD. The comparisons are also extended into regions where nonperturbative effects become large, and in this way the transition from hard to soft QCD is investigated. It is found that by including leading and next-to-leading logarithmic contributions in the QCD predictions, the agreement with the data can be extended to lower transverse momentum sca...
Axial vector diquark correlations in the nucleon: structure functions and static properties
Energy Technology Data Exchange (ETDEWEB)
Mineo, H. E-mail: mineo@nt.phys.s.u-tokyo.ac.jp; Bentz, W.; Ishii, N.; Yazaki, K
2002-06-03
In order to extract information on the strength of quark-quark correlations in the axial vector (a.v.) diquark channel (J{sup P}=1{sup +},T=1), we analyze the quark light cone momentum distributions in the nucleon, in particular their flavor dependencies, and the static properties of the nucleon. To construct the nucleon as a relativistic 3-quark bound state, we use a simple 'static' approximation to the full Faddeev equation in the Nambu-Jona-Lasinio model, including correlations in the scalar (J{sup P}=0{sup +},T=0) and a.v. diquark channels. It is shown that the a.v. diquark correlations should be rather weak compared to the scalar ones. From our analysis we extract information on the strength of the correlations as well as on the probability of the a.v. diquark channel.
A contribution to the static and dynamic calculation of research reactor structures
International Nuclear Information System (INIS)
Goncalves Filho, O.J.A.; Brito Aghina, L.O. de; Gomes, P.A.
1978-01-01
Some results in the analysis of a research reactor, using the finite element method are presented. The distribution of internal forces is discussed for the conditions of a Borax accident. An special computer automatic program for the static and dynamic analysis of this Kind of reactor buildings was developed. The program may use either plane triangular elements or double-curvature shell elements and allows the analysis of laminated shells, as it the case of concrete containment vessels with steel liners. (Author)
Dynamical rescaling, the EMC effect and universality of hadron structure functions
International Nuclear Information System (INIS)
Close, F.E.
1984-04-01
Data are compared on the EMC effect, with the hypothesis that the quark confinement size increases in going from a free nucleon to a nucleus. In QCD a dynamical rescaling is predicted: Q 2 variation of the distribution function in a given target parallels the dependence on confinement size, R, at fixed Q 2 . Thus a dynamical scale invariance obtains when both R and Q 2 are varied, yielding the dynamical rescaling relation F 2 sup(A)(x, Q 2 ) = F 2 sup(N)(x, zetaQ 2 ) where zeta > 1 is predicted for any nucleus and is a function of the confinement size. Data on 12 nuclei agree with this, implying that confinement size is governed by nuclear density. The formalism is tested by relating the pion and nucleon structure functions. (author)
Static structure of chameleon dark matter as an explanation of dwarf spheroidal galaxy cores
Chanda, Prolay Krishna; Das, Subinoy
2017-04-01
We propose a novel mechanism that explains the cored dark matter density profile in recently observed dark matter rich dwarf spheroidal galaxies. In our scenario, dark matter particle mass decreases gradually as a function of distance towards the center of a dwarf galaxy due to its interaction with a chameleon scalar. At closer distance towards the Galactic center the strength of attractive scalar fifth force becomes much stronger than gravity and is balanced by the Fermi pressure of the dark matter cloud; thus, an equilibrium static configuration of the dark matter halo is obtained. Like the case of soliton star or fermion Q-star, the stability of the dark matter halo is obtained as the scalar achieves a static profile and reaches an asymptotic value away from the Galactic center. For simple scalar-dark matter interaction and quadratic scalar self-interaction potential, we show that dark matter behaves exactly like cold dark matter (CDM) beyond a few kpc away from the Galactic center but at closer distance it becomes lighter and Fermi pressure cannot be ignored anymore. Using Thomas-Fermi approximation, we numerically solve the radial static profile of the scalar field, fermion mass and dark matter energy density as a function of distance. We find that for fifth force mediated by an ultralight scalar, it is possible to obtain a flattened dark matter density profile towards the Galactic center. In our scenario, the fifth force can be neglected at distance r ≥1 kpc from the Galactic center and dark matter can be simply treated as heavy nonrelativistic particles beyond this distance, thus reproducing the success of CDM at large scales.
Direct observation of quark-hadron duality in the free neutron ${F}_{2}$ structure function
Energy Technology Data Exchange (ETDEWEB)
Niculescu, I. [James Madison Univ., Harrisonburg, VA (United States); Niculescu, G. [James Madison Univ., Harrisonburg, VA (United States); Melnitchouk, W. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Arrington, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Christy, M. E. [Hampton Univ., Hampton, VA (United States); Ent, R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Griffioen, K. A. [College of William and Mary, Williamsburg, VA (United States); Kalantarians, N. [Hampton Univ., Hampton, VA (United States); Keppel, C. E. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Kuhn, S. [Old Dominion Univ., Norfolk, VA (United States); Tkachenko, S. [Univ. of Virginia, Charlottesville, VA (United States); Zhang, J. [Univ. of Virginia, Charlottesville, VA (United States)
2015-05-21
Using data from the recent BONuS experiment at Jefferson Lab, which utilized a novel spectator tagging technique to extract the inclusive electron-free neutron scattering cross section, we obtain the first direct observation of quark-hadron duality in the neutron F_{2} structure function. In addition, the data are used to reconstruct the lowest few (N = 2, 4 and 6) moments of F_{2} in the three prominent nucleon resonance regions, as well as the moments integrated over the entire resonance region. Comparison with moments computed from global parametrizations of parton distribution functions suggest that quark--hadron duality holds locally for the neutron in the second and third resonance regions down to Q^{2} ≈ 1 GeV^{2}, with violations possibly up to 20% observed in the first resonance region.
International Nuclear Information System (INIS)
Babaev, Z.R.; Shchelkachev, A.V.
1991-01-01
Prospects of decribing polarization effects within the framework of quark-parton models (QPM) using a density matrix in order to describe the parton spin states in hadrons are discussed. Such an approach allows one to get rid of contradictions occuring when describing the QPM of reactions of hadrons polarized in perpendicular to the scattering plane in case of applying spin distribution functions. Different model predictions for the observed one- and two-spin correlations in elastic nucleon-nucleon scattering are analyzed. 12 refs., 2 tabs
Hadron seagulls and parton jets
International Nuclear Information System (INIS)
Satz, H.; Zarmi, Y.
1976-01-01
For the lepton production of hadrons in the current fragmentation region it was recently shown that the two-level partonic picture leads to a broadening of the average transverse momentum of the observed secondaries. This ''seagull'' effect is well known for hadron-hadron interactions. In the note it is considered the possibility that parton arguments can explain it here as well and it is discussed what information on the constituent structure of hadrons can be obtained through an investigation of the seagull effect from such a point of view. It is shown that a non trivial seagull effect is a consequence of a simple two step production mechanism and the parton model predicts significant differences between baryon, meson and virtual-photon fragmentation seagull
HERWIG for Hadron-Hadron physics
International Nuclear Information System (INIS)
Seymour, M.H.
1993-05-01
HERWIG is a general-purpose particle physics event generator, which includes the simulation of any combination of hard lepton, hadron or photon scattering and soft hadron-hadron collisions in one package. It uses the parton-shower approach for initial-state and final-state QCD radiation, including colour coherence effects and azimuthal correlations both within and between jets. This article describes HERWIG version 5.6, and gives a brief review of the physics underlying HERWIG, with particular emphasis on hadron-hadron collisions. Details are given of the input and control parameters used by the program
International Nuclear Information System (INIS)
Pahl, Christoph Johannes
2008-01-01
In hadron production data of the e + e - annihilation experiments JADE and OPAL we measure the first five moments of twelve hadronic-event-shape variables at c.m. energies from 14 to 207 GeV. From the comparison of the QCD NLO prediction with the data corrected by means of MC models about hadronization we obtain the reference value of the strong coupling α s (M Z 0 )=0.1254±0.0007(stat.)±0.0010(exp.) +0.0009 -0.0 0 23 (had.) +0.0069 -0.0053 (theo.). For some, especially higher moments, systematic unsufficiencies in the QCD NLO prediction are recognizable. Simultaneous fits to two moments under assumption of identical renormalization scales yield scale values from x μ =0.057 to x μ =0.196. We check predictions of different non-perturbative models. From the single-dressed-gluon approximation a perturbative prediction in O(α 5 s ) results with neglegible energy power correction, which describes the thrust average on hadron level well with α s (M Z 0 )=0.1186±0,0017(exp.) -0.0028 +0.0033 (theo.). The variance of the event-shape variable is measured and compared with models as well as predictions. [de
Hadronic molecules with hidden charm and bottom
Directory of Open Access Journals (Sweden)
Guo Feng-Kun
2016-01-01
Full Text Available Many of the new structures observed since 2003 in experiments in the heavy quarkonium mass region, such as the X(3872 and Zc (3900, are rather close to certain thresholds, and thus can be good candidates of hadronic molecules, which are loose bound systems of hadrons. We will discuss the consequences of heavy quark symmetry for hadronic molecules with heavy quarks. We will also emphasize that the hadronic molecular component of a given structure can be directly probed in long-distance processes, while the short-distance processes are not sensitive to it.
International Nuclear Information System (INIS)
Ishikawa, K.; Schierholz, G.; Teper, M.; Schneider, H.
1982-12-01
We present some techniques for elucidating hadronic structure via lattice Monte Carlo calculations. Applying these techniques, we measure the fluctuations of colour magnetic and electric fields as well as the topological charge density inside and outside the lowest lying 0 + and 2 + glueballs in the SU(2) non-abelian lattice gauge theory. This gives us a detailed picture of the glueball structure. We also obtain, as a by-product, a reliable estimate of the gluon condensate sup(αs)/sub(π) and an estimate of the O - glueball mass which agrees with our previous estimates. (orig.)
Instantons, the QCD vacuum, and hadronic physics
International Nuclear Information System (INIS)
Negele, J.W.
1999-01-01
A large body of evidence from lattice calculations indicates that instantons play a major role in the physics of light hadrons. This evidence is summarized, and recent results concerning the instanton content of the SU(3) vacuum, instanton contributions to the static potential, and a new class of instanton solutions at finite temperature are reviewed
Scott, Robert C.; Bartels, Robert E.
2009-01-01
This paper examines the aeroelastic stability of an on-orbit installable Space Shuttle patch panel. CFD flutter solutions were obtained for thick and thin boundary layers at a free stream Mach number of 2.0 and several Mach numbers near sonic speed. The effect of structural damping on these flutter solutions was also examined, and the effect of structural nonlinearities associated with in-plane forces in the panel was considered on the worst case linear flutter solution. The results of the study indicated that adequate flutter margins exist for the panel at the Mach numbers examined. The addition of structural damping improved flutter margins as did the inclusion of nonlinear effects associated with a static pressure difference across the panel.
Huang, Wen; Koric, Seid; Yu, Xin; Hsia, K Jimmy; Li, Xiuling
2014-11-12
Micro- and nanoscale tubular structures can be formed by strain-induced self-rolled-up nanomembranes. Precision engineering of the shape and dimension determines the performance of devices based on this platform for electronic, optical, and biological applications. A transient quasi-static finite element method (FEM) with moving boundary conditions is proposed as a general approach to design diverse types of three-dimensional (3D) rolled-up geometries. This method captures the dynamic release process of membranes through etching driven by mismatch strain and accurately predicts the final dimensions of rolled-up structures. Guided by the FEM modeling, experimental demonstration using silicon nitride membranes was achieved with unprecedented precision including controlling fractional turns of a rolled-up membrane, anisotropic rolling to form helical structures, and local stress control for 3D hierarchical architectures.
DEFF Research Database (Denmark)
Skafte, Anders; Kristoffersen, Julie; Vestermark, Jonas
2017-01-01
into two parts using complementary filters: Low frequency response caused by the quasi-static effect of the waves acting on the structure, and the high frequency response given by the modal properties of the structure. The high frequency response is then decomposed into modal coordinates using...... the experimental mode shapes. Strain histories are predicted by multiplying the modal coordinates with the expanded strain mode shapes. The low frequency response is decomposed using Ritz-vectors corresponding to the shapes that the structure vibrates with due to the wave loading. Strain Ritz......-vectors are then extracted from the finite element model by applying a load corresponding to a representative wave and the strain history for the low frequency response is found by multiplying the decomposed signal with the strain Ritz-vectors. Finally the combined strain history is found by adding the strain histories from...
International Nuclear Information System (INIS)
Nagy, M.; Krupa, D.
1989-01-01
The proceedings contain the full texts of all 43 papers presented at the conference. All contributions have been inputted to INIS. The topics covered include the chiral aspects of QCD; nonperturbative QCD; heavy ion collisions and quark-gluon plasma signatures; and recent experimental results. (Z.S.)
Non linear fe analysis on the static buckling behavior of the spacer grid structures
International Nuclear Information System (INIS)
Song, K.N.; Yoon, K.H.
2001-01-01
In this study considered is the static buckling behavior of spacer grids in the fuel assembly, which are required to have a sufficient strength against an accident like earthquake. Special attention is given to the finite element modeling of the spot-welding and the constraints between the spacer strips assembled together: it is found that a proper treatment of the constraints is critical for accurate assessment of the buckling behavior including strain localization at the point of spot welding. The buckling strength of the 17 x 17 spacer grid, which is difficult to analyze due to a large number of degrees of freedom, is estimated from analysis for the smaller models 3 x 3, 5 x 5, 7 x 7, and 9 x 9 spacer grids. (authors)
Quantum groups in hadron phenomenology
International Nuclear Information System (INIS)
Gavrilik, A.M.
1997-01-01
We show that application of quantum unitary groups, in place of ordinary flavor SU(n f ), to such static aspects of hadron phenomenology as hadron masses and mass formulas is indeed fruitful. So-called q-deformed mass formulas are given for octet baryons 1/2 + and decuplet baryons 3/2 + , as well as for the case of vector mesons 1 - involving heavy flavors. For deformation parameter q, rigid fixation of values is used. New mass sum rules of remarkable accuracy are presented. As shown in decuplet case, the approach accounts for effects highly nonlinear in SU(3)-breaking. Topological implication (possible connection with knots) for singlet vector mesons and the relation q ↔ Θ c (Cabibbo angle) in case of baryons are considered
Barate, R; Ghez, P; Goy, C; Lees, J P; Merle, E; Minard, M N; Pietrzyk, B; Alemany, R; Casado, M P; Chmeissani, M; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Pacheco, A; Park, I C; Riu, I; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Becker, U; Boix, G; Cattaneo, M; Cerutti, F; Ciulli, V; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Halley, A W; Hansen, J B; Harvey, J; Janot, P; Jost, B; Lehraus, Ivan; Leroy, O; Mato, P; Minten, Adolf G; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Rousseau, D; Schlatter, W D; Schmitt, M; Schneider, O; Spagnolo, P; Tejessy, W; Teubert, F; Tomalin, I R; Tournefier, E; Ajaltouni, Ziad J; Badaud, F; Chazelle, G; Deschamps, O; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Rougé, A; Rumpf, M; Swynghedauw, M; Verderi, M; Videau, H L; Focardi, E; Parrini, G; Zachariadou, K; Cavanaugh, R J; Corden, M; Georgiopoulos, C H; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Lynch, J G; Negus, P; O'Shea, V; Raine, C; Teixeira-Dias, P; Thompson, A S; Buchmüller, O L; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Marinelli, N; Sciabà, A; Sedgbeer, J K; Thomson, E; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bowdery, C K; Buck, P G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Robertson, N A; Williams, M; Giehl, I; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Wachsmuth, H W; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Carr, J; Coyle, P; Etienne, F; Ealet, A; Motsch, F; Payre, P; Talby, M; Thulasidas, M; Aleppo, M; Antonelli, M; Ragusa, F; Büscher, V; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Mannert, C; Männer, W; Moser, H G; Schael, S; Settles, Ronald; Seywerd, H C J; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Le Diberder, F R; Lefrançois, J; Lutz, A M; Schune, M H; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Bettarini, S; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Giassi, A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sguazzoni, G; Tenchini, Roberto; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Chambers, J T; Cowan, G D; Green, M G; Medcalf, T; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S L; Combley, F; Kelly, M S; Lehto, M H; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Foss, J; Grupen, Claus; Prange, G; Smolik, L; Stephan, F; Giannini, G; Gobbo, B; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Charles, E; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Greening, T C; Hayes, O J; Hu, H; Jin, S; Mamier, G; McNamara, P A; Nachtman, J M; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Vogt, M; Walsh, J; Wu Sau Lan; Wu, X; Zobernig, G
1999-01-01
Inclusive gamma^*gamma interactions to hadronic final states where one scattered electron or positron is detected in the electromagnetic calorimeters have been studied in the LEP 1 data taken by ALEPH from 1991 to 1995. The event sample has been used to measure the hadronic structure function of the photon F_2^gamma in three bins with of 9.9, 20.7 and 284 GeV^2.
Structural optimization of static power control programs of nuclear power plants with WWER-1000
International Nuclear Information System (INIS)
Kokol, E.O.
2015-01-01
The question of possibility the power control programs switching for WWER-1000 is considered. The aim of this research is to determine the best program for the power control of nuclear reactor under cyclic diurnal behavior of electrical generation, as well as the switching implementation. The considered problem of finding the best control program refers to the multicriteria optimization class of problems. Operation of the nuclear power generation system simulated using the following power control programs: with constant average temperature of transfer fluid, with constant pressure in the reactor secondary circuit, with constant temperature in input of the nuclear reactor. The target function was proposed. It consists of three normalized criteria: the burn up fraction, the damage level of fuel rod array shells, as well as changes in the power values. When simulation of the nuclear power generation system operation within the life was done, the values of the selected criteria were obtained and inserted in the target function. The minimum of three values of the target function depending on the control program at current time defined the criterion of switching of considered static power control programs for nuclear power generation system
Hadron muoproduction at the COMPASS experiment
Rajotte, J F
The COMPASS Collaboration has two main fields of interest: to improve our knowledge of the nucleon spin structure and to study hadrons through spectroscopy. These goals require a multipurpose universal spectrometer such as the COmmon Muon and Proton Apparatus for Structure and Spectroscopy, COMPASS. In its first years of data taking (2002-2007), the nucleon spin structure was studied with a polarized muon beam scattering off a polarized target. These studies resumed in 2010 and will continue until at least 2011. The years 2008 and 2009 were dedicated to hadron spectroscopy using hadron beams. In the case of the nucleon structure studies, it is crucial to detect with high precision the incoming beam muon (160 GeV), the scattered muon and the produced hadrons. The large amount of high quality data accumulated provides access to the unpolarized and polarized parton distributions of the nucleon and the hadronization process. Subtle differences (asymmetries) between polarized cross sections have been predicted for...
Quasi-static drift-tube accelerating structures for low-speed heavy ions
International Nuclear Information System (INIS)
Faltens, A.; Keefe, D.
1978-01-01
A pulsed drift-tube accelerating structure for use in Heavy Ion Fusion applications is described. Possible arrangements of components in such a structure, the injector design needs, and the influence of the existing state of component technology on drift-tube structure design are considered. It is concluded that the major attractions of the pulsed drift tubes are that they are nonresonant structures and that they appear suitable for accelerating a very high current bunch at low energies. The mechanical tolerances of the nonresonant structure are very loose and the cost per meter should be low; the cost of the transport system is expected to be the major cost. The pulse-power modulators used to drive the drift tubes are inexpensive compared with rf sources of equivalent peak power. The longitudinal emittance of the beam emerging from the structure could be extremely low. (U.K.)
Acciarri, M; Adriani, O; Aguilar-Benítez, M; Ahlen, S P; Alpat, B; Alcaraz, J; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Antreasyan, D; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banicz, K; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bencze, G L; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Borgia, B; Boucham, A; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Brambilla, Elena; Branson, J G; Brigljevic, V; Brock, I C; Buijs, A; Bujak, A T; Burger, J D; Burger, W J; Burgos, C; Busenitz, J K; Buytenhuijs, A O; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Caria, M; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Castello, R; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chan, A; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, C; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chéreau, X J; Chiefari, G; Chien, C Y; Choi, M T; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coan, T E; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Dai, T S; D'Alessandro, R; De Asmundis, R; De Boeck, H; Degré, A; Deiters, K; Dénes, E; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dorne, I; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabbretti, R; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Felcini, Marta; Ferguson, T; Fernández, D; Fernández, G; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Forconi, G; Fredj, L; Freudenreich, Klaus; Gailloud, M; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; González, E; Gougas, Andreas; Goujon, D; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gustafson, H R; Gutay, L J; Hangarter, K; Hartmann, B; Hasan, A; He, J T; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Ilyas, M M; Innocente, Vincenzo; Janssen, H; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamyshkov, Yu A; Kapinos, P; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kittel, E W; Klimentov, A; Koffeman, E; Köngeter, A; Koutsenko, V F; Koulbardis, A; Krämer, R W; Kramer, T; Krenz, W; Kuijten, H; Kunin, A; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee Jae Sik; Lee, K Y; Leggett, C; Le Goff, J M; Leiste, R; Lenti, M; Leonardi, E; Levchenko, P M; Li Chuan; Lieb, E H; Lin, W T; Linde, Frank L; Lindemann, B; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Ludovici, L; Luminari, L; Lustermann, W; Ma Wen Gan; Macchiolo, A; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangla, S; Maolinbay, M; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; McNally, D; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Möller, M; Monteleoni, B; Moore, R; Morganti, S; Mount, R; Müller, S; Muheim, F; Nagy, E; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nippe, A; Nowak, H; Organtini, G; Ostonen, R; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Raghavan, R; Rahal-Callot, G; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Redaelli, M; Ren, D; Rescigno, M; Reucroft, S; Ricker, A; Riemann, S; Riemers, B C; Riles, K; Rind, O; Ro, S; Robohm, A; Rodin, J; Rodríguez-Calonge, F J; Roe, B P; Röhner, S; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Rykaczewski, H; Salicio, J; Salicio, J M; Sánchez, E; Santocchia, A; Sarakinos, M E; Sarkar, S; Sassowsky, M; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Schneegans, M; Schöneich, B; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schulte, R; Schultze, K; Schwenke, J; Schwering, G; Sciacca, C; Seiler, P G; Sens, Johannes C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Siedenburg, T; Son, D; Sopczak, André; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Sticozzi, F; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Toker, O; Tonisch, F; Tonutti, M; Tonwar, S C; Tóth, J; Tsaregorodtsev, A Yu; Tully, C; Tuchscherer, H; Tung, K L; Ulbricht, J; Urbàn, L; Uwer, U; Valente, E; Van de Walle, R T; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vuilleumier, L; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Y F; Wang, Z M; Weber, A; Weill, R; Willmott, C; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zaccardelli, C; Zalite, A; Zemp, P; Zeng, J Y; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, G J; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Van der Zwaan, B C C
1996-01-01
We present a study of the structure of hadronic events recorded by the L3 detector at center-of-mass energies of 130 and 136 GeV. The data sample corresponds to an integrated luminosity of 5 pb-1 collected during the high energy run of 1995. The shapes of the event shape distributions and the energy dependence of their mean values are well reproduced by QCD models. From a comparison of the data with resummed O(alpha_s^2) QCD calculations, we determine the strong coupling constant to be alpha_s(133 GeV) = 0.107 +/- 0.005(exp) +/- 0.006(theor).
Energy Technology Data Exchange (ETDEWEB)
Bhatnagar, Shashank [Department of Physics, Addis Ababa University, PO Box 101739, Addis Ababa (Ethiopia); Li Shiyuan [Department of Physics, Shandong University, Jinan, 250100 (China)
2006-07-15
We employ the framework of the Bethe-Salpeter equation under a covariant instantaneous ansatz to study the leptonic decays of vector mesons. The structure of the hadron-quark vertex function {gamma} is generalized to include various Dirac covariants (other than i{gamma} . {epsilon}) from their complete set. They are incorporated in accordance with a naive power counting rule order-by-order in powers of the inverse of the meson mass. The decay constants for {rho}, {omega} and {phi} mesons are calculated with the incorporation of leading-order covariants.
International Nuclear Information System (INIS)
Bhatnagar, Shashank; Li Shiyuan
2006-01-01
We employ the framework of the Bethe-Salpeter equation under a covariant instantaneous ansatz to study the leptonic decays of vector mesons. The structure of the hadron-quark vertex function Γ is generalized to include various Dirac covariants (other than iγ . ε) from their complete set. They are incorporated in accordance with a naive power counting rule order-by-order in powers of the inverse of the meson mass. The decay constants for ρ, ω and φ mesons are calculated with the incorporation of leading-order covariants
Energy Technology Data Exchange (ETDEWEB)
Xu, Ke [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing 100191 (China); Niu, Liang-Liang [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing 100191 (China); Department of Nuclear Engineering and Radiological Science, University of Michigan, Ann Arbor, MI 48109 (United States); Jin, Shuo, E-mail: jinshuo@buaa.edu.cn [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing 100191 (China); Shu, Xiaolin [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing 100191 (China); Xie, Hongxian [School of Mechanical Engineering, Hebei University of Technology, Tianjin 300132 (China); Wang, Lifang; Lu, Guang-Hong [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing 100191 (China)
2017-02-15
Atomistic simulations have been used to investigate the core structures, static properties of isolated 1/2 <1 1 1> screw dislocations, and their interaction with vacancies in bcc tungsten (W) based on three empirical interatomic potentials. Differential displacement maps show that only one embedded atom method potential is able to reproduce the compact non-degenerate core as evidenced by ab initio calculations. The obtained strain energy and stress distribution from atomistic simulations are, in general, consistent with elasticity theory predictions. In particular, one component of the calculated shear stress, which is not present according to elasticity theory, is non-negligible in the core region of our dislocation model. The differences between the results calculated from three interatomic potentials are in details, such as the specific value and the symmetry, but the trend of spatial distributions of static properties in the long range are close to each other. By calculating the binding energies between the dislocations and vacancies, we demonstrate that the dislocations act as vacancy sinks, which may be important for the nucleation and growth of hydrogen bubbles in W under irradiation.
International Nuclear Information System (INIS)
Knudsen, D.J.; Kelley, M.C.; Earle, G.D.; Vickrey, J.F.; Boehm, M.
1990-01-01
The authors present and analyze sounding rocket and HILAT satellite measurements of the low frequency ( 0 in the auroral oval. By examining the time-domain field data it is often difficult to distinguish temporal fluctuations from static structures which are Doppler shifted to a non-zero frequency in the spacecraft frame. However, they show that such a distinction can be made by constructing the impedance function Z(f). Using Z(f) they find agreement with the static field interpretation below about 0.1 Hz in the spacecraft frame, i.e. Z(f) = Σ p -1 where Σ p is the height-integrated Pedersen conductivity of the ionosphere. About 0.1 Hz the authors find Z(f) > Σ p -1 , which they argue to be due to the presence of Alfven waves incident from the magnetosphere and reflecting from the lower ionosphere, forming a standing wave pattern. These waves may represent an electromagnetic coupling mechanism between the auroral acceleration region and the ionosphere
Ground state structure of U2Mo: static and lattice dynamics study
International Nuclear Information System (INIS)
Mukherjee, D.; Sahoo, B.D.; Joshi, K.D.; Kaushik, T.C.
2016-01-01
According to experimental reports, the ground state stable structure of U 2 Mo is tetragonal. However, various theoretical studies performed in past do not get tetragonal phase as the stable structure at ambient conditions. Therefore, the ground state structure of U 2 Mo is still unresolved. In an attempt to understand the ground state properties of this system, we have carried out first principle electronic band structure calculations. The structural stability analysis carried out using evolutionary structure search algorithm in conjunction with ab-inito method shows that a hexagonal structure (space group P6/mmm) is the lowest enthalpy structure at ambient condition and remains stable upto 200 GPa. The elastic and lattice dynamical stability further supports the stability of this phase at ambient condition. Further, using the 0 K calculations in conjunction with finite temperature corrections, we have derived the isotherm and shock adiabat (Hugoniot) of this material. Various equilibrium properties such as ambient pressure volume, bulk modulus, pressure derivative of bulk modulus etc. are derived from equation of state. (author)
Development and static testing of the 18x6 m SSU-TTMBF spatial structural unit
Deordiev, S.; Frolovskaia, A.; Krasiev, M.
2018-03-01
The aim of this work is the development of a fragment of the structural covering, consisting of a triangular block of frames, the choice of step size (width) of the structural unit and a study of its mode of deformation by comparing experimental and theoretical results of research.
Le, Jia-Liang; Bažant, Zdeněk P.; Bazant, Martin Z.
2011-07-01
Engineering structures must be designed for an extremely low failure probability such as 10 -6, which is beyond the means of direct verification by histogram testing. This is not a problem for brittle or ductile materials because the type of probability distribution of structural strength is fixed and known, making it possible to predict the tail probabilities from the mean and variance. It is a problem, though, for quasibrittle materials for which the type of strength distribution transitions from Gaussian to Weibullian as the structure size increases. These are heterogeneous materials with brittle constituents, characterized by material inhomogeneities that are not negligible compared to the structure size. Examples include concrete, fiber composites, coarse-grained or toughened ceramics, rocks, sea ice, rigid foams and bone, as well as many materials used in nano- and microscale devices. This study presents a unified theory of strength and lifetime for such materials, based on activation energy controlled random jumps of the nano-crack front, and on the nano-macro multiscale transition of tail probabilities. Part I of this study deals with the case of monotonic and sustained (or creep) loading, and Part II with fatigue (or cyclic) loading. On the scale of the representative volume element of material, the probability distribution of strength has a Gaussian core onto which a remote Weibull tail is grafted at failure probability of the order of 10 -3. With increasing structure size, the Weibull tail penetrates into the Gaussian core. The probability distribution of static (creep) lifetime is related to the strength distribution by the power law for the static crack growth rate, for which a physical justification is given. The present theory yields a simple relation between the exponent of this law and the Weibull moduli for strength and lifetime. The benefit is that the lifetime distribution can be predicted from short-time tests of the mean size effect on
International Nuclear Information System (INIS)
Dremin, I.M.
1981-01-01
The process of the coherent production of hadrons analogous to Cherenkov radiation of photons is considered. Its appearence and qualitative treatment are possible now because it is known from experiment that the real part of the πp (and pp) forward elastic scattering amplitude is positive at high energies. The threshold behaviour of the process as well as very typical angular and psub(T)-distributions where psub(t)-transverse momentum corresponding to the ring structure of the target diagram at rather large angles and to high-psub(T) jet production are emphasized [ru
International Nuclear Information System (INIS)
Futakawa, M.; Iyoku, T.
1996-01-01
For pt.IV see ibid., vol.154, p.83-95, 1995. The graphite components in high temperature gas-cooled reactors are connected to each other through a key-keyway structure that has gaps between the key and the keyway to accommodate thermal expansion. Because a dynamic load concentrates on the key-keyway structure during earthquakes, it is considered to be a crucial element for assessing the integrity of the graphite components. A combination of experiments and analyses was employed to investigate the dynamic behavior of the key-keyway structure, i.e. the equivalent stiffness associated with vibrational characteristics of the graphite components and the stress distribution under dynamic loading. The experiments were performed using a graphite scale model and a dynamic photo-elastic method. The analysis was carried out using the finite element method (FEM) code ABAQUS, taking account of the contact behavior between the key and the keyway. The following conclusions were derived. (1) The equivalent stiffness of the key-keyway structure shows nonlinearity, owing to the contact deformation. (2) The equivalent stiffness evaluated by the FEM analysis, taking account of the non-linear contact deformation, is applicable for predicting the vibrational characteristics of the key-keyway structure. (3) The stress concentration under dynamic loading is lower than or nearly equal to that under static loading. The maximum stress concentration of the seismic load can be sufficiently evaluated under static loading conditions. (orig.)
Quasi-static drift-tube accelerating structures for low-speed heavy ions
International Nuclear Information System (INIS)
Faltens, A.; Keefe, D.
1977-01-01
The major attractions of the pulsed drift-tubes are that they are non-resonant structures and that they appear suitable for accelerating a very high current bunch at low energies. The mechanical tolerances of the non-resonant structure are very loose and the cost per meter should be low; the cost of the transport system is expected to be the major cost. The pulse power modulators used to drive the drift-tubes are inexpensive compared to r.f. sources with equivalent peak-power. The longitudinal emittance of the beam emerging from the structure could be extremely low
Mounting LHCb hadron calorimeter scintillating tiles
Maximilien Brice
2004-01-01
Scintillating tiles are carefully mounted in the hadronic calorimeter for the LHCb detector. These calorimeters measure the energy of particles that interact via the strong force, called hadrons. The detectors are made in a sandwich-like structure where these scintillator tiles are placed between metal sheets.
Light-Front Dynamics in Hadron Physics
Ji, C.R.; Bakker, B.L.G.; Choi, H.M.
2013-01-01
Light-front dynamics(LFD) plays an important role in the analyses of relativistic few-body systems. As evidenced from the recent studies of generalized parton distributions (GPDs) in hadron physics, a natural framework for a detailed study of hadron structures is LFD due to its direct application in
Multiphase static droplet simulations in hierarchically structured super-hydrophobic surfaces
Energy Technology Data Exchange (ETDEWEB)
Lee, Jung Shin; Lee, Joon Sang [School of Mechanical Engineering, Yonsei University, Seoul (Korea, Republic of)
2016-08-15
The surface of first part of study is textured with microscopic pillars of prototypical top geometries as a rectangle. The second one is textured with a hierarchical structure, composed of secondary pillar structures added on the primary texture. The length ratio between two scales of texture is 1:16. We evaluated the non-wetting characteristics of two types of surfaces by measuring CAs as well as the transition from the Wenzel's to Cassie's regimes. We measure the Contact angles (CAs), using the Lattice Boltzmann model (LBM), for two different surface configurations. We evaluated the effect of the hierarchical structure; the robustness of the Cassie regime is enhanced and the apparent contact angle is increased by the secondary structures. This is achieved by increasing the energy barrier against the transition between wetting and non-wetting regimes.
Energy Technology Data Exchange (ETDEWEB)
Solvignon, Patricia [Temple Univ., Philadelphia, PA (United States)
2006-08-01
One of the biggest challenges in the study of the nucleon structure is the understanding of the transition from partonic degrees of freedom to hadronic degrees of freedom. In 1970, Bloom and Gilman noticed that structure function data taken at SLAC in the resonance region average to the scaling curve of deep inelastic scattering (DIS). Early theoretical interpretations suggested that these two very different regimes can be linked under the condition that the quark-gluon and quark-quark interactions are suppressed. Substantial efforts are ongoing to investigate this phenomenon both experimentally and theoretically. Quark-hadron duality has been confirmed for the unpolarized structure function F_{2} of the proton and the deuteron using data from the experimental Hall C at Jefferson Lab (JLab). Indications of duality have been seen for the proton polarized structure function g_{1} and the virtual photon asymmetry A_{1} at JLab Hall B and HERMES. Because of the different resonance behavior, it is expected that the onset of duality for the neutron will happen at lower momentum transfer than for the proton. Now that precise spin structure data in the DIS region are available at large x, data in the resonance region are greatly needed in order to test duality in spin-dependent structure functions. The goal of experiment E01-012 was to provide such data on the neutron (^{3}He) in the moderate momentum transfer (Q^{2}) region, 1.0 < Q^{2} < 4.0 (GeV/c^{2}), where duality is expected to hold. The experiment ran successfully in early 2003 at Jefferson Lab in Hall B. It was an inclusive measurement of longitudinally polarized electrons scattering from a longitudinally or transversely polarized ^{3}He target. Asymmetries and cross section differences were measured in order to extract the ^{3}He spin structure function g_{1} and virtual photon asymmetry A_{1} in the resonance region. A test
International Nuclear Information System (INIS)
Patricia Solvignon
2006-01-01
One of the biggest challenges in the study of the nucleon structure is the understanding of the transition from partonic degrees of freedom to hadronic degrees of freedom. In 1970, Bloom and Gilman noticed that structure function data taken at SLAC in the resonance region average to the scaling curve of deep inelastic scattering (DIS). Early theoretical interpretations suggested that these two very different regimes can be linked under the condition that the quark-gluon and quark-quark interactions are suppressed. Substantial efforts are ongoing to investigate this phenomenon both experimentally and theoretically. Quark-hadron duality has been confirmed for the unpolarized structure function F 2 of the proton and the deuteron using data from the experimental Hall C at Jefferson Lab (JLab). Indications of duality have been seen for the proton polarized structure function g 1 and the virtual photon asymmetry A 1 at JLab Hall B and HERMES. Because of the different resonance behavior, it is expected that the onset of duality for the neutron will happen at lower momentum transfer than for the proton. Now that precise spin structure data in the DIS region are available at large x, data in the resonance region are greatly needed in order to test duality in spin-dependent structure functions. The goal of experiment E01-012 was to provide such data on the neutron ( 3 He) in the moderate momentum transfer (Q 2 ) region, 1.0 2 2 ), where duality is expected to hold. The experiment ran successfully in early 2003 at Jefferson Lab in Hall B. It was an inclusive measurement of longitudinally polarized electrons scattering from a longitudinally or transversely polarized 3 He target. Asymmetries and cross section differences were measured in order to extract the 3 He spin structure function g 1 and virtual photon asymmetry A 1 in the resonance region. A test of quark-hadron duality has then been performed for the 3 He and neutron structure functions. The study of spin duality for
International Nuclear Information System (INIS)
Gray, M.N.; Cheung, S.C.H.; Dixon, D.A.
1984-09-01
A laboratory investigation of the vertical and lateral swelling pressures developed in statically compacted, air-dry specimens of sodium (Na)-bentonite:silica sand mixtures as they are saturated in confined conditions with double-distilled, deionized water is described. The results are interpreted with the aid of observations of the compacted soil structures made in a scanning electron microscope. It is shown that the sand acts as an inert filler material and vertical swelling pressures are controlled by a parameter termed the effective clay dry density (qsub(c)). A limiting value of qsub(c) exists below which vertical and lateral swelling pressures do not differ and are theoretically predictable. Above this value, vertical pressures exceed lateral ones. This is related to a change from an isotropic to an anisotropic soil fabric as qsub(c) is increased above the limiting value
International Nuclear Information System (INIS)
Sun, Zuo-Yu; Li, Guo-Xiu; Wang, Lan; Wang, Wei-Hong; Gao, Qing-Xiu; Wang, Jie
2016-01-01
Highlights: • The static electromagnetic characteristics of solenoid valve were numerically studied. • The effects of driving current were considered. • The effects of solenoid valve’s eight essential structure parameters were considered. - Abstract: In the present paper, the effects of driving current and solenoid valve’s structure parameters (including iron-core’s length, magnetic pole’s cross-sectional area, coil turn, coil’s position, armature’s thickness, damping hole’s position, damping hole’s size, and width of working air–gap) on the static electromagnetic characteristics have been numerically investigated. From the results, it can be known that the electromagnetic energy conversion will be seriously influenced by driving current for its effects on magnetic field strength and magnetic saturation phenomenon, an excessive increase of current will weak electromagnetic energy conversion for the accelerating power losses. The capacity of electromagnetic energy conversion is also relative to each solenoid valve’s parameter albeit it is not very sensitive to each parameters. The generated electromagnetic force will be enhanced by rising iron-core’s length, equalizing the cross-sectional areas of major and vice poles, increasing coil turn within a moderate range, closing the coil’s position towards armature’s centre, enlarging armature’s thickness, pushing the damping holes’ positions away from armature’s centre, reducing the sizes of damping holes, and reducing the width of working air–gap; but such enhancements won’t be realized once the driving current is excessively higher.
International Nuclear Information System (INIS)
Ghodrati Amiri, G.; Amidi, S.; Khorasani, M.
2008-01-01
In the recent years, scientists developed the seismic rehabilitation of structures and their view points were changed from sufficient strength to the performance of structures (Performance Base Design) to prepare a safe design. Nonlinear Static Procedure analysis (NSP) or pushover analysis is a new method that is chosen for its speed and simplicity in calculations. 'Seismic Rehabilitation Code for Existing Buildings' and FEMA 356 considered this method. Result of this analysis is a target displacement that is the base of the performance and rehabilitation procedure of the structures. Exact recognition of that displacement could develop the workability of pushover analysis. In these days, Nonlinear Dynamic Analysis (NDP) is only method can exactly apply the seismic ground motions. In this case because it consumes time, costs very high and is more difficult than other methods, is not applicable as much as NSP. A coefficient used in NSP for determining the target displacement is C2 (Stiffness and Strength Degradations Coefficient) and is applicable for correcting the errors due to eliminating the stiffness and strength degradations in hysteretic loops. In this study it has been tried to analysis three concrete frames with shear walls by several accelerations that scaled according to FEMA 273 and FEMA 356. These structures were designed with Iranian 2800 standard (vers.3). Finally after the analyzing by pushover method and comparison results with dynamic analysis, calculated C2 was comprised with values in rehabilitation codes
International Nuclear Information System (INIS)
Lumma, D.; Lurio, L. B.; Borthwick, M. A.; Falus, P.; Mochrie, S. G. J.
2000-01-01
X-ray photon correlation spectroscopy and small-angle x-ray scattering measurements are applied to characterize the dynamics and structure of concentrated suspensions of charge-stabilized polystyrene latex spheres dispersed in glycerol, for volume fractions between 2.7% and 52%. The static structures of the suspensions show essentially hard-sphere behavior. The short-time dynamics shows good agreement with predictions for the wave-vector-dependent collective diffusion coefficient, which are based on a hard-sphere model [C. W. J. Beenakker and P. Mazur, Physica A 126, 349 (1984)]. However, the intermediate scattering function is found to violate a scaling behavior found previously for a sterically stabilized hard-sphere suspension [P. N. Segre and P. N. Pusey, Phys. Rev. Lett. 77, 771 (1996)]. Our measurements are parametrized in terms of a viscoelastic model for the intermediate scattering function [W. Hess and R. Klein, Adv. Phys. 32, 173 (1983)]. Within this framework, two relaxation modes are predicted to contribute to the decay of the dynamic structure factor, with mode amplitudes depending on both wave vector and volume fraction. Our measurements indicate that, for particle volume fractions smaller than about 0.30, the intermediate scattering function is well described in terms of single-exponential decays, whereas a double-mode structure becomes apparent for more concentrated systems
DEFF Research Database (Denmark)
Jakobsen, Bo
2006-01-01
The main goal of the study presented in this thesis was to perform in-situ investigations on deformation structures in plastically deformed polycrystalline copper at low degrees of tensile deformation (model system for cell forming pure fcc metals. Anovel synchrotron...... grains in polycrystalline samples during tensile deformation. We have shown that the resulting 3D reciprocal space maps from tensile deformed copper comprise a pronounced structure, consisting of bright sharp peaks superimposed on a cloud of enhanced intensity. Based on the integrated intensity......, the width of the peaks, and spatial scanning experiments it is concluded that the individual peaks arise from individual dislocation-free regions (the subgrains) in the dislocation structure. The cloud is attributed to the dislocation rich walls. Samples deformed to 2% tensile strain were investigated under...
Meißner, Ulf-G.
2004-01-01
The status of hadron physics at the end of the HADRON07 Conference is reviewed. The latest results presented at the conference, as well as those important developments in the field which were not represented, are included.
QCD in hadron-hadron collisions
International Nuclear Information System (INIS)
Albrow, M.
1997-03-01
Quantum Chromodynamics provides a good description of many aspects of high energy hadron-hadron collisions, and this will be described, along with some aspects that are not yet understood in QCD. Topics include high E T jet production, direct photon, W, Z and heavy flavor production, rapidity gaps and hard diffraction
High energy hadron-hadron collisions
International Nuclear Information System (INIS)
Chou, T.T.
1990-01-01
Results of a study on high energy collision with the geometrical model are summarized in three parts: (i) the elastic hadron-hadron collision, (ii) the inelastic hadron-hadron collision, and (iii) the e + e - annihilation. The geometrical description of high-energy elastic scattering developed earlier is still in general agreement with experiments at the CERN-S bar ppS energies. A simple one-parameter expression for the blackness of bar pp system has been proposed recently which describes very well all existing data from ISR to S bar ppS energies. The geometrical description has also been extended to include processes of fragmentation and diffraction dissociation and other phenomena. In the past five years, a unified physical picture for multiparticle emission in hadron-hadron and e + e - collisions was developed. It focuses on the idea of the wide range of values for the total angular momentum in hadron-hadron collisions. An extension of this consideration yields a theory for the momentum distribution of the outgoing particles which agrees with bar pp and e + e - collision experiments. The results and conclusions of this theory have been extrapolated to higher energies and yielded many predictions which can be experimentally tested. 37 refs
The Emergence of Hadrons from QCD Color
Brooks, William; Color Dynamics in Cold Matter (CDCM) Collaboration
2015-10-01
The formation of hadrons from energetic quarks, the dynamical enforcement of QCD confinement, is not well understood at a fundamental level. In Deep Inelastic Scattering, modifications of the distributions of identified hadrons emerging from nuclei of different sizes reveal a rich variety of spatial and temporal characteristics of the hadronization process, including its dependence on spin, flavor, energy, and hadron mass and structure. The EIC will feature a wide range of kinematics, allowing a complete investigation of medium-induced gluon bremsstrahlung by the propagating quarks, leading to partonic energy loss. This fundamental process, which is also at the heart of jet quenching in heavy ion collisions, can be studied for light and heavy quarks at the EIC through observables quantifying hadron ``attenuation'' for a variety of hadron species. Transverse momentum broadening of hadrons, which is sensitive to the nuclear gluonic field, will also be accessible, and can be used to test our understanding from pQCD of how this quantity evolves with pathlength, as well as its connection to partonic energy loss. The evolution of the forming hadrons in the medium will shed new light on the dynamical origins of the forces between hadrons, and thus ultimately on the nuclear force. Supported by the Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) of Chile.
Analog automatic test pattern generation for quasi-static structural test.
Zjajo, A.; Pineda de Gyvez, J.
2009-01-01
A new approach for structural, fault-oriented analog test generation methodology to test for the presence of manufacturing-related defects is proposed. The output of the test generator consists of optimized test stimuli, fault coverage and sampling instants that are sufficient to detect the failure
CMS Central Hadron Calorimeter
Budd, Howard S.
2001-01-01
We present a description of the CMS central hadron calorimeter. We describe the production of the 1996 CMS hadron testbeam module. We show the results of the quality control tests of the testbeam module. We present some results of the 1995 CMS hadron testbeam.
Problems of hadron electrodynamics
International Nuclear Information System (INIS)
Rekalo, M.P.
1989-01-01
Certain directions of hadron electrodynamics referring to testing symmetry properties relatively to C-, P- and T-transformations; determination of fundamental electromagnetic characteristics of hadrons as well as to clarifying the dynamics of electromagnetic processes in which hadrons participate are analyzed briefly. 52 refs
“Markhi” spatial design structure: numerical study of its work under static load
Directory of Open Access Journals (Sweden)
Alpatov Vadim
2016-01-01
Full Text Available There is a problem of internal stress volume existing for some types of spatial structures and their joint connections. The problem occurs when a massive body is used as a joint connector. It is quite simple to determine tension on this joint connector surface using electric resistive tensometry method. It is not simple though to empirically determine internal tension in the massive body of the connector. To determine internal tension we can use modern calculation systems, such as Ansys, Abaqus, CosmosWorks, Nastran, Autodesk Inventor, Robot Structural Analysis, Bentley STAAD, CSI SAP2000; etc: Internal tension analysis in a massive joint connector makes possible to select both surplus stock parts and shortage stock parts. In this paper the authors base their analysis on both surface and internal tension of MARKHI connector and come up with solutions for its improvement.
Static disorder and structural correlations in the low-temperature phase of lithium imide
Miceli, Giacomo; Ceriotti, Michele; Bernasconi, Marco; Parrinello, Michele
2011-02-01
Based on ab initio molecular dynamics simulations, we investigate the low-temperature crystal structure of Li2NH which in spite of its great interest as H-storage material is still a matter of debate. The dynamical simulations reveal a precise correlation in the fractional occupation of Li sites which leads average atomic positions in excellent agreement with diffraction data and solves the inconsistencies of previous proposals.
A quasi-static approach to structure formation in black hole universes
Energy Technology Data Exchange (ETDEWEB)
Durk, Jessie; Clifton, Timothy, E-mail: j.durk@qmul.ac.uk, E-mail: t.clifton@qmul.ac.uk [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London (United Kingdom)
2017-10-01
Motivated by the existence of hierarchies of structure in the Universe, we present four new families of exact initial data for inhomogeneous cosmological models at their maximum of expansion. These data generalise existing black hole lattice models to situations that contain clusters of masses, and hence allow the consequences of cosmological structures to be considered in a well-defined and non-perturbative fashion. The degree of clustering is controlled by a parameter λ, in such a way that for λ ∼ 0 or 1 we have very tightly clustered masses, whilst for λ ∼ 0.5 all masses are separated by cosmological distance scales. We study the consequences of structure formation on the total net mass in each of our clusters, as well as calculating the cosmological consequences of the interaction energies both within and between clusters. The locations of the shared horizons that appear around groups of black holes, when they are brought sufficiently close together, are also identified and studied. We find that clustering can have surprisingly large effects on the scale of the cosmology, with models that contain thousands of black holes sometimes being as little as 30% of the size of comparable Friedmann models with the same total proper mass. This deficit is comparable to what might be expected to occur from neglecting gravitational interaction energies in Friedmann cosmology, and suggests that these quantities may have a significant influence on the properties of the large-scale cosmology.
Directory of Open Access Journals (Sweden)
Slava Svitlana S.
2015-03-01
Full Text Available Under current conditions in Ukraine, when the vector is directed at increasing self-sufficiency of the regions, diagnostics of structural transformations in their economic systems is a mandatory and necessary component to identify potential points of the region development. Accordingly, the purpose of the article is to study the structural trends in the economy of the Transcarpathian region and identify its leading sectors under the pre-crisis and crisis conditions, balance in dynamics of the main indicators — the volume of sales, regional value added, capital investment and the number of employees, as well as formation of the main directions in development of the regional economy. It has been revealed that for the past ten years the restructuring of the region economic did not go on too rapidly and it is still difficult to speak about a clear trend of transition to a post-industrial system. Given the current characteristics of the economy of Transcarpathia, the article defined the basic problematic aspects of its structural transformation. It allowed to determine the long-term, according to the authors, ways of “modernization” of economic processes in terms of attracting investments, increasing innovation, business activity, formation of a complete production cycle, use of alternative energy sources, implementation of the EU requirements.
A quasi-static approach to structure formation in black hole universes
International Nuclear Information System (INIS)
Durk, Jessie; Clifton, Timothy
2017-01-01
Motivated by the existence of hierarchies of structure in the Universe, we present four new families of exact initial data for inhomogeneous cosmological models at their maximum of expansion. These data generalise existing black hole lattice models to situations that contain clusters of masses, and hence allow the consequences of cosmological structures to be considered in a well-defined and non-perturbative fashion. The degree of clustering is controlled by a parameter λ, in such a way that for λ ∼ 0 or 1 we have very tightly clustered masses, whilst for λ ∼ 0.5 all masses are separated by cosmological distance scales. We study the consequences of structure formation on the total net mass in each of our clusters, as well as calculating the cosmological consequences of the interaction energies both within and between clusters. The locations of the shared horizons that appear around groups of black holes, when they are brought sufficiently close together, are also identified and studied. We find that clustering can have surprisingly large effects on the scale of the cosmology, with models that contain thousands of black holes sometimes being as little as 30% of the size of comparable Friedmann models with the same total proper mass. This deficit is comparable to what might be expected to occur from neglecting gravitational interaction energies in Friedmann cosmology, and suggests that these quantities may have a significant influence on the properties of the large-scale cosmology.
A quasi-static approach to structure formation in black hole universes
Durk, Jessie; Clifton, Timothy
2017-10-01
Motivated by the existence of hierarchies of structure in the Universe, we present four new families of exact initial data for inhomogeneous cosmological models at their maximum of expansion. These data generalise existing black hole lattice models to situations that contain clusters of masses, and hence allow the consequences of cosmological structures to be considered in a well-defined and non-perturbative fashion. The degree of clustering is controlled by a parameter λ, in such a way that for λ ~ 0 or 1 we have very tightly clustered masses, whilst for λ ~ 0.5 all masses are separated by cosmological distance scales. We study the consequences of structure formation on the total net mass in each of our clusters, as well as calculating the cosmological consequences of the interaction energies both within and between clusters. The locations of the shared horizons that appear around groups of black holes, when they are brought sufficiently close together, are also identified and studied. We find that clustering can have surprisingly large effects on the scale of the cosmology, with models that contain thousands of black holes sometimes being as little as 30% of the size of comparable Friedmann models with the same total proper mass. This deficit is comparable to what might be expected to occur from neglecting gravitational interaction energies in Friedmann cosmology, and suggests that these quantities may have a significant influence on the properties of the large-scale cosmology.
International Nuclear Information System (INIS)
Cahill, R.T.
1992-01-01
A review is given of progress in deriving the effective action for hadronic physics, S[π, ρ, ω, .., anti N, N, ..], from the fundamental defining action of QCD, S[anti q, q, A μ a ]. This is a problem in quantum field theory and the most success so far has been achieved using functional integral calculus (FIC) techniques. This formulates the problem as an exercise in changing the variables of integration in the functional integrals, from those of the quark and gluon fields to those of the (bare) meson and baryon fields. The appropriate variables are determined by the dynamics of QCD, and the final hadronic variables (essentially the 'normal modes' of QCD) are local fields describing the 'centre-of-mass' motion of extended bound states of quarks. The quarks are extensively dressed by the gluons, and the detailed aspects of the hidden chiral symmetry emerge naturally from the formalism. Particular attention is given to covariant integral equations which determine bare nucleon structure (i.e. in the quenched approximation). These equations, which arise from the closed double-helix diagrams of the FIC analysis, describe the baryons in terms of quark-diquark structure, in the form of Faddeev equations. This hadronisation of QCD also generates the dressing of these baryons by the pions, and the non-local πNN coupling. (orig.)
Hadron excitation of giant resonances
International Nuclear Information System (INIS)
Morsch, H.-P.
1985-01-01
A review is given on giant resonance studies in heavy nuclei using scattering of different hadronic probes. Concerning isoscalar giant resonances compression modes are discussed with the possibility to obtain more detailed structure information. From detailed studies of α scattering the distribution of isoscalar strengths of multipolarity up to L=6 was obtained. Some recent aspects of heavy ion excitation of collective modes are mentioned. The possibility to study isovector giant resonances in hadron charge exchange reactions is discussed. Finally, a comparison is made between α and 200 MeV proton scattering from which isoscalar and spin-isospin continuum response are extracted. (orig.)
Hadron scattering, resonances, and QCD
Briceño, R. A.
2016-11-01
The non-perturbative nature of quantum chromodynamics (QCD) has historically left a gap in our understanding of the connection between the fundamental theory of the strong interactions and the rich structure of experimentally observed phenomena. For the simplest properties of stable hadrons, this is now circumvented with the use of lattice QCD (LQCD). In this talk I discuss a path towards a rigorous determination of few-hadron observables from LQCD. I illustrate the power of the methodology by presenting recently determined scattering amplitudes in the light-meson sector and their resonance content.
Composite hadrons and relativistic nuclei
International Nuclear Information System (INIS)
Blankenbecler, R.
1978-01-01
Lectures are presented describing a model of hadronic scattering at large momentum transfer, either transverse or longitudinal. This model emphasizes in this regime the importance of forces involving the interchange of constituents of the hadrons, hence its name, the constituent interchange model CIM. The CIM is a rearrangement of standard perturbation theory to take into account the fact that the binding force is very strong in color singlet states (singlet dominance). The hard scattering expansion, incoherence problems, nuclear wave functions and counting rules, interaction between nuclei, pion and proton yields and form factors, structure functions and nonscaling, massive lepton pairs, hadrons at large transverse momentum, and quark-quark scattering are treated. 49 references
The COMPASS Hadron Spectroscopy Programme
Austregesilo, A
2011-01-01
COMPASS is a fixed-target experiment at the CERN SPS for the investigation of the structure and the dynamics of hadrons. The experimental setup features a large acceptance and high momentum resolution spectrometer including particle identification and calorimetry and is therefore ideal to access a broad range of different final states. Following the promising observation of a spin-exotic resonance during an earlier pilot run, COMPASS focused on light-quark hadron spectroscopy during the years 2008 and 2009. A data set, world leading in terms of statistics and resolution, has been collected with a 190GeV/c hadron beam impinging on either liquid hydrogen or nuclear targets. Spin-exotic meson and glueball candidates formed in both diffractive dissociation and central production are presently studied. Since the beam composition includes protons, the excited baryon spectrum is also accessible. Furthermore, Primakoff reactions have the potential to determine radiative widths of the resonances and to probe chiral pe...
Hadron Contribution to Vacuum Polarisation
Davier, M; Malaescu, B; Zhang, Z
2016-01-01
Precision tests of the Standard Theory require theoretical predictions taking into account higher-order quantum corrections. Among these vacuum polarisation plays a predominant role. Vacuum polarisation originates from creation and annihilation of virtual particle–antiparticle states. Leptonic vacuum polarisation can be computed from quantum electrodynamics. Hadronic vacuum polarisation cannot because of the non-perturbative nature of QCD at low energy. The problem is remedied by establishing dispersion relations involving experimental data on the cross section for e+ e− annihilation into hadrons. This chapter sets the theoretical and experimental scene and reviews the progress achieved in the last decades thanks to more precise and complete data sets. Among the various applications of hadronic vacuum polarisation calculations, two are emphasised: the contribution to the anomalous magnetic moment of the muon, and the running of the fine structure constant α to the Z mass scale. They are fundamental ingre...
Dimensional Reduction and Hadronic Processes
International Nuclear Information System (INIS)
Signer, Adrian; Stoeckinger, Dominik
2008-01-01
We consider the application of regularization by dimensional reduction to NLO corrections of hadronic processes. The general collinear singularity structure is discussed, the origin of the regularization-scheme dependence is identified and transition rules to other regularization schemes are derived.
Feigenbaum constants in hadron collisions
International Nuclear Information System (INIS)
Batunin, A.V.
1991-01-01
The coincidence is found between the law n ch (s) growth in hadron collisions for symmetric rapidity intervals and the law of growth of the number of elements in limit 2 m -cycles for one-dimensional quadratic maps when a govering parameter is varied. Fractal structure of the corresponding attractor underlies intermittency phenomenon in the multiplicity distribution of particles. 12 refs.; 1 fig
International Nuclear Information System (INIS)
Maglich, Bogdan C.
2004-01-01
High resolution has been discouraged in meson spectrometry for 4 decades by the Doctrine of Experiments Incompatible with Theory (DEIT). DEIT a priori rejects narrow hadron resonances on the paradigm that only broad hadron peaks, Γ≥ 100 MeV, can exist -- in spite of the accumulated evidence to the contrary. The facts are: Mesons 2 orders of magnitude narrower than 'allowed' for hadrons, have been confirmed; a new one was announced at this conference. Narrow meson structures have been repeatedly reported at high momentum transfer, vertical bar t vertical bar >0.2, while they are absent at the low transfer, vertical bar t vertical bar ∼0.01, where 99% of the experiments are performed. Modification of meson mass and width as a function of the density of nuclear matter in which they are produced, have been recently reported.We postulate for meson spectra: (1) Intrinsic ('true') width, Γ, is different from the observable ('apparent') width, Γ': Γ< Γ' (2) Γ of all meson states are narrow and can be observed only at or near the maximum vertical bar t vertical bar reachable in the reaction, and (3) Γ of all meson resonances are subject to broadening as vertical bar t vertical bar decreases. Since both Γ' and the production σ are inversely proportional to vertical bar t vertical ar, most of the observed spectra are produced at the lowest vertical bar t vertical bar <0.01 and thus the peaks appear broad. We have conceptually designed a novel type hadron spectrometer with an order of magnitude better resolution (0.1 MeV). It would operate at 2 orders of magnitude higher vertical bar t vertical bar (0.3< vertical bar t vertical bar <1 (GeV/c)2, than most experiments to date (vertical bar t vertical bar <0.01). Mesons in the mass region 0.5 < Mx<5 GeV would be produced in πP→PX (baryons in PP→PP*) in a 'solid state hydrogen target' consisting of an array of plastic scintillator fibers, CH; collisions with C are electronically rejected. Missing mass of P is
Jiang, Caigui
2014-09-01
This paper builds on recent progress in computing with geometric constraints, which is particularly relevant to architectural geometry. Not only do various kinds of meshes with additional properties (like planar faces, or with equilibrium forces in their edges) become available for interactive geometric modeling, but so do other arrangements of geometric primitives, like honeycomb structures. The latter constitute an important class of geometric objects, with relations to “Lobel” meshes, and to freeform polyhedral patterns. Such patterns are particularly interesting and pose research problems which go beyond what is known for meshes, e.g. with regard to their computing, their flexibility, and the assessment of their fairness.
3-dimensional finite element modelling of reactor building internal structure for static analysis
International Nuclear Information System (INIS)
Joshi, M.H.; Reddy, V.J.; Kushwaha, H.S.; Reddy, G.R.; Karandikar, G.V.
1991-01-01
a) Thin shell element gives fairly accurate results when compared to 3-D Brick element for the type of structure and loading in Reactor Building. b) The maximum element size is fixed from model 3(c) i.e. 2.0 m. c) Openings with size smaller than 0.5 m can be neglected without affecting the results very much. d) For any such problem, the methodology described in this paper can be used to take rational decisions which will ensure reasonable accuracy. (author)
QUASI-STATIC MODEL OF MAGNETICALLY COLLIMATED JETS AND RADIO LOBES. II. JET STRUCTURE AND STABILITY
Energy Technology Data Exchange (ETDEWEB)
Colgate, Stirling A.; Li, Hui [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fowler, T. Kenneth [University of California, Berkeley, CA 94720 (United States); Hooper, E. Bickford [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); McClenaghan, Joseph; Lin, Zhihong [University of California, Irvine, CA 92697 (United States)
2015-11-10
This is the second in a series of companion papers showing that when an efficient dynamo can be maintained by accretion disks around supermassive black holes in active galactic nuclei, it can lead to the formation of a powerful, magnetically driven, and mediated helix that could explain both the observed radio jet/lobe structures and ultimately the enormous power inferred from the observed ultrahigh-energy cosmic rays. In the first paper, we showed self-consistently that minimizing viscous dissipation in the disk naturally leads to jets of maximum power with boundary conditions known to yield jets as a low-density, magnetically collimated tower, consistent with observational constraints of wire-like currents at distances far from the black hole. In this paper we show that these magnetic towers remain collimated as they grow in length at nonrelativistic velocities. Differences with relativistic jet models are explained by three-dimensional magnetic structures derived from a detailed examination of stability properties of the tower model, including a broad diffuse pinch with current profiles predicted by a detailed jet solution outside the collimated central column treated as an electric circuit. We justify our model in part by the derived jet dimensions in reasonable agreement with observations. Using these jet properties, we also discuss the implications for relativistic particle acceleration in nonrelativistically moving jets. The appendices justify the low jet densities yielding our results and speculate how to reconcile our nonrelativistic treatment with general relativistic MHD simulations.
International Nuclear Information System (INIS)
Hanson, G.; Alam, M.S.; Boyarski, A.M.; Breidenbach, M.; Bulos, F.; Dakin, J.T.; Dorfan, J.M.; Feldman, G.J.; Fischer, G.E.; Fryberger, D.; Hartill, D.L.; Jaros, J.A.; Jean-Marie, B.; Larsen, R.R.; Lueth, V.; Lynch, H.L.; Lyon, D.; Morehouse, C.C.; Paterson, J.M.; Perl, M.L.; Peruzzi, I.; Piccolo, M.; Pun, T.P.; Rapidis, P.; Richter, B.; Schindler, R.H.; Schwitters, R.F.; Siegrist, J.L.; Tanenbaum, W.; Vannucci, F.; Abrams, G.S.; Briggs, D.; Carithers, W.C.; Chinowsky, W.; Cooper, S.; DeVoe, R.G.; Friedberg, C.E.; Goldhaber, G.; Hollebeek, R.J.; Johnson, A.D.; Kadyk, J.A.; Litke, A.M.; Madaras, R.J.; Nguyen, H.K.; Pierre, F.M.; Sadoulet, B.; Trilling, G.H.; Whitaker, J.S.; Winkelmann, F.C.; Wiss, J.E.
1982-01-01
We present results on the jet structure observed in multihadronic events produced by e + e - annihilation in the Mark I magnetic detector at SPEAR. The evidence for jet structure and the jet-axis angular distribution are reported. We give inclusive distributions of the hadrons in Feynman x, rapidity, and transverse momentum relative to the jet axis
The temperature dependence of the static structure factor for liquid 4He below Tsub(lambda)
International Nuclear Information System (INIS)
Puoskari, M.; Kallio, A.; Pollari, P.
1984-01-01
The temperature dependence of the structure factor S(k,T) is studied based on an assumption that the anomalous behaviour of S(k,T) below Tsub(lambda) is due to thermally excited rotons and phonons. The calculation of S(k,T) is performed with the help of the HNC-equation from a model density matrix of Penrose which in turn is obtained from a quasiparticle Hamiltonian describing elementary excitations of liquid helium (both phonons and rotons). The results are in qualitative agreement with recent neutron and X-ray scattering experiments below Tsub(lambda). The theoretical temperature correction is used to deduce S(k,T=0) separately from the most recent X-ray and neutron scattering experiments. (Auth.)
2002-01-01
The aim of the experiment is to study the following topics: a) The influence of parton structure on low p^t hadron-hadron collisions. b) Strangeness flow and correlations in fragmentation. c) Meson-Nucleus collisions. The data are expected to throw light on the still uncalculable (soft) quark fragmentation mechanism, in particular when the 'tagged' strange quark of the K|+ beam is involved as parent quark.\\\\ \\\\ The experiment is done with the European Hybrid Spectrometer which has a large geometrical acceptance combined with good momentum resolution and with very powerful particle identification. The general layout is shown in the Figure. With a very general trigger, a wealth of reactions will be accumulated, which will permit a detailed study of an umbiased sample of events. For all topics of physics under study, it is highly desirable and for some even absolutely essential that the experimental set-up contains the forward Cerenkov detector and th radiation detector. For topic c), the rapid cycling bubble ch...
Small static electric field strength promotes aggregation-prone structures in amyloid-β(29-42)
Lu, Yan; Shi, Xiao-Feng; Salsbury, Freddie R.; Derreumaux, Philippe
2017-04-01
The formation of senile plaques in central neural system resulting from the aggregation of the amyloid β (Aβ) of 40 and 42 residues is one of the two hallmarks of Alzheimer's disease. Numerous experiments and computational studies have shown that the aggregation of Aβ peptides in vitro is very complex and depends on many factors such as pH, agitation, temperature, and peptide concentration. The impact of a static electric field (EF) on amyloid peptide aggregation has been much less studied, although EFs may have some applications to treat Parkinson's disease symptoms. Here, we study the influence of an EF strength of 20 mV/nm, present in the human brains, on the conformation of the Aβ29-42 dimer. Our 7 μs non-equilibrium atomistic simulations in aqueous solution show that this field-strength promotes substantially the formation of β-hairpins, believed to be a very important intermediate state during aggregation. This work also suggests that structural biology experiments conducted under appropriate EF strengths may help reduce the conformational heterogeneity of Aβ1-40/Aβ1-42 dimers and provide significant insights into their structures that may be disease-causing.
Udovenko, Anatoly; Laptash, Natalia
2015-08-01
Single crystals of tungsten double salt (NH4)3WO2F5 = (NH4)3[WO2F4]F have been synthesized by solid-state reaction or from fluoride solution and its crystal structures at 296 and 193 K were determined by X-ray diffraction. At room temperature, the crystal structure of the compound is dynamically disordered with the ligand atoms statistically distributed on two positions (6e and 24m) of the Pm3m unit cell [a = 6.0298 (1) Å], and the tungsten atom dynamically disordered on 12 orientations forming a spatial cuboctahedron [W12] that enables the real geometry of cis-WO2F4 octahedron to be determined with two short W-O distances. On cooling, the compound undergoes a first-order phase transition with the symmetry change Pm3m → Pa3 and a doubling of the unit-cell parameter [a = 11.9635 (7) Å]. The ligand F(O) atoms statistically occupy two general 24d sites and form W1X6 and W2X6 octahedra, in which the O and F atoms are not crystallographically different that means a static orientational disorder of (NH4)3WO2F5.
Amsler, Claude
2000-01-01
The experimental status of glueballs and hybrids is briefly reviewed. Recent results for scalar mesons suggest that f sub 0 (1500) is the ground state scalar glueball. The identification of the first excited glueball state, a tensor, is premature, although candidates are available. We have now evidence for at least two mesons, pi sub 1 (1400) and pi sub 1 (1600), with quantum numbers incompatible with a qq-bar structure.
Ventilation and internal structure effects on naturally induced flows in a static aircraft wing
International Nuclear Information System (INIS)
Moore, Daithi; Newport, David; Egan, Vanessa; Lacarac, Vesna
2012-01-01
The ventilation performance within an aircraft wing leading edge is investigated for a number of enclosure and ventilation configurations. The natural convection regime present is found to be highly sensitive to enclosure conditions, particularly the introduction of a partition. The presence of a partition reduced the overall heat exhausted from the cavity by up to 60%. The optimum ventilation strategy is also changed from a forward biased vent orientation (found for the unpartitioned case), to one where both the rear and front vents within the enclosure had the same open area. Cylinder plume effects dominate within the enclosure and were the main driver of the convective regime, with steady-state enclosure conditions highly dependent upon cylinder placement and plume orientation. An externally heated enclosure with internal heat source, combined with ventilation and an internal structure produced a complex natural convection regime which is sensitive to enclosure conditions. Hence an adequate knowledge of such conditions is necessary in order to fully appreciate the convective regime. - Highlights: → Optimum ventilation strategy changed between unpartitioned and partitioned cases. → Flow path and plume orientation are important to consider when analysing ventilation. → Bleed duct placement significantly alters flow path and temperature distribution. → Enclosure partitioning reduced heat exhaustion by 60%.
International Nuclear Information System (INIS)
1997-01-01
The workshop brought together about thirty invited participants from around the world, and an almost equal number of Brookhaven users and staff, to discuss recent developments and future prospects for hadronic strong interaction studies at high energy, particularly relating to the RHIC project at Brookhaven. RIKEN and Brookhaven have long traditions in and commitments to the study of the strong interactions, and the advent of the RHIC collider will open new opportunities both for relativistic heavy ion and polarized proton-proton studies. Activities at the RIKEN BNL Research Center are intended to focus on physics opportunities stimulated by this new facility. Thus, one of the purposes of the center is to provide a forum where workers in the field can gather to share and develop their ideas in a stimulating environment. The purpose of the workshop was both to delineate theoretical problems and stimulate collaborations to address them. The workshop focused primarily, but not exclusively, on spin and small-x physics
International Nuclear Information System (INIS)
Olsen, S.L.
2014-01-01
QCD-motivated models for hadrons predict an assortment of "exotic" hadrons that have structures that are more complex than the quark-antiquark mesons and three-quark baryons of the original quark-parton model. These include pentaquark baryons, the six-quark H-dibaryon, and tetraquark and glueball mesons. Despite extensive experimental searches, no unambiguous candidates for any of these exotic configurations have yet to be identified. On the other hand, a number of meson states, one that seems to be a proton-antiproton bound state, and others that contain either charmed-anticharmed quark pairs or bottom-antibottom quark pairs, have been recently discovered that neither fit into the quark-antiquark meson picture nor match the expected properties of the QCD-inspired exotics. Here I briefly review results from a recent search for the H-dibaryon, and discuss some properties of the newly discovered states –the so-called XYZ mesons– and compare them with expectations for conventional quark-antiquark mesons and the predicted QCD-exotic states. (author)
International Nuclear Information System (INIS)
Dzhelyadin, R.I.
2002-01-01
The Hadron Calorimeter (HCAL) is designed for the LHCb experiment. The main purpose of the detector is to provide data for the L0 hadron trigger. The HCAL is designed as consisting of two symmetric movable parts of about 500 ton in total getting in touch in operation position without non-instrumented zones. The lateral dimensions of an active area are X=8.4 m width, Y=6.8 m height, and is distanced from the interaction point at Z=13.33 m. Both halves are assembled from stacked up modules. An internal structure consisting of thin iron plates interspaced with scintillating tiles has been chosen. Attention is paid to optimize the detector according to the requirements of the experiment, reducing the spending needed for its construction. Different construction technologies are being discussed. The calorimeter properties have been extensively studied with a variety of prototype on the accelerator beam. The calibration with a radioactive source and module-0 construction experience is discussed
Track segments in hadronic showers in a highly granular scintillator-steel hadron calorimeter
Adloff, C.; Chefdeville, M.; Drancourt, C.; Gaglione, R.; Geffroy, N.; Karyotakis, Y.; Koletsou, I.; Prast, J.; Vouters, G.; Francis, K.; Repond, J.; Schlereth, J.; Smith, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S.T.; Sosebee, M.; White, A.P.; Yu, J.; Eigen, G.; Mikami, Y.; Watson, N.K.; Mavromanolakis, G.; Thomson, M.A.; Ward, D.R.; Yan, W.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Dannheim, D.; Dotti, A.; Folger, G.; Ivantchenko, V.; Klempt, W.; Kraaij, E.van der; Lucaci-Timoce, A.-I; Ribon, A.; Schlatter, D.; Uzhinskiy, V.; Cârloganu, C.; Gay, P.; Manen, S.; Royer, L.; Tytgat, M.; Zaganidis, N.; Blazey, G.C.; Dyshkant, A.; Lima, J.G.R.; Zutshi, V.; Hostachy, J.-Y; Morin, L.; Cornett, U.; David, D.; Falley, G.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krüger, K.; Lu, S.; Morozov, S.; Morgunov, V.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Feege, N.; Garutti, E.; Laurien, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Schultz-Coulon, H.-Ch; Shen, W.; Stamen, R.; Bilki, B.; Norbeck, E.; Onel, Y.; Wilson, G.W.; Kawagoe, K.; Sudo, Y.; Yoshioka, T.; Dauncey, P.D.; Magnan, A.-M; Bartsch, V.; Wing, M.; Salvatore, F.; Gil, E.Cortina; Mannai, S.; Baulieu, G.; Calabria, P.; Caponetto, L.; Combaret, C.; Negra, R.Della; Grenier, G.; Han, R.; Ianigro, J-C; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Donckt, M.Vander; Zoccarato, Y.; Alamillo, E.Calvo; Fouz, M.-C; Puerta-Pelayo, J.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Kirikova, N.; Kozlov, V.; Smirnov, P.; Soloviev, Y.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Karakash, A.; Popova, E.; Tikhomirov, V.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Callier, S.; Lorenzo, S.Conforti di; Cornebise, P.; Doublet, Ph; Dulucq, F.; Fleury, J.; Frisson, T.; der Kolk, N.van; Li, H.; Martin-Chassard, G.; Richard, F.; Taille, Ch de la; Pöschl, R.; Raux, L.; Rouëné, J.; Seguin-Moreau, N.; Anduze, M.; Balagura, V.; Boudry, V.; Brient, J-C; Cornat, R.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Magniette, F.; Musat, G.; Ruan, M.; Tran, T.H.; Videau, H.; Bulanek, B.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Kotera, K.; Takeshita, T.; Uozumi, S.; Jeans, D.; Götze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.
2013-01-01
We investigate the three dimensional substructure of hadronic showers in the CALICE scintillator-steel hadronic calorimeter. The high granularity of the detector is used to find track segments of minimum ionising particles within hadronic showers, providing sensitivity to the spatial structure and the details of secondary particle production in hadronic cascades. The multiplicity, length and angular distribution of identified track segments are compared to GEANT4 simulations with several different shower models. Track segments also provide the possibility for in-situ calibration of highly granular calorimeters.
Peng, Wei; Ding, Fei
2017-10-24
Chirality is a ubiquitous basic attribute of nature, which inseparably relates to the life activity of living organisms. However, enantiomeric differences have still failed to arouse enough attention during the biological evaluation and practical application of chiral substances, and this poses a large threat to human health. In the current study, we explore the enantioselective biorecognition of a chiral compound by an asymmetric biomolecule, and then decipher the molecular basis of such a biological phenomenon on the static and, in particular, the dynamic scale. In light of the wet experiments, in silico docking results revealed that the orientation of the latter part of the optical isomer structures in the recognition domain can be greatly affected by the chiral carbon center in a model ligand molecule, and this event may induce large disparities between the static chiral bioreaction modes and noncovalent interactions (especially hydrogen bonding). Dynamic stereoselective biorecognition assays indicated that the conformational stability of the protein-(S)-diclofop system is clearly greater than the protein-(R)-diclofop adduct; and moreover, the conformational alterations of the diclofop enantiomers in the dynamic process will directly influence the conformational flexibility of the key residues found in the biorecognition region. These points enable the changing trends of biopolymer structural flexibility and free energy to exhibit significant distinctions when proteins sterically recognize the (R)-/(S)-stereoisomers. The outcomes of the energy decomposition further showed that the van der Waals' energy has roughly the same contribution to the chiral recognition biosystems, whereas the contribution of electrostatic energy to the protein-(R)-diclofop complex is notably smaller than to the protein-(S)-diclofop bioconjugate. This proves that differences in the noncovalent bonds would have a serious impact on the stereoselective biorecognition between a
Coulomb interference and bending slope in hadron-hadron scattering
International Nuclear Information System (INIS)
Pereira, Flavio I.; Ferreira, Erasmo
1994-01-01
With the purpose of testing the results of QCD calculations on the structure of the forward elastic scattering cross-section, we analyse the coulombic-nuclear interference occurring at small values of the momentum transfer. We emphasize the influence of the hadronic structures on the determination of the Coulomb phase and consequently on the t-dependence of the strong interaction slope parameter. (author)
Quantum chromodynamics and the dynamics of hadrons
International Nuclear Information System (INIS)
Brodsky, S.J.
1979-03-01
The application of perturbative quantum chromodynamics to the dynamics of hadrons at short distance is reviewed, with particular emphasis on the role of the hadronic bound state. A number of new applications are discussed, including the modification to QCD scaling violations in structure functions due to hadronic binding; a discussion of coherence and binding corrections to the gluon and sea-quark distributions; QCD radiative corrections to dimensional counting rules for exclusive processes and hadronic form factors at large momentum transfer; generalized counting rules for inclusive processes; the special role of photon-induced reactions in QCD, especially applications to jet production in photon-photon collisions, and photon production at large transverse momentum. Also presented is a short review of the central problems in large P/sub T/ hadronic reactions and the distinguishing characteristics of gluon and quark jets. 163 references
Hadron--hadron reactions, high multiplicity
International Nuclear Information System (INIS)
Diebold, R.
1978-09-01
A coverage of results on high energy and high multiplicity hadron reactions, charm searches and related topics, ultrahigh energy events and exotic phenomena (cosmic rays), and the nuclear effects in high energy collisions and related topics is discussed. 67 references
International Nuclear Information System (INIS)
Xie Yigang; Chai Yong
1994-01-01
The charged multiplicity distributions of hadron final states in the e + e - annihilation at the 91.2 GeV Z 0 energy region are fitted with Poisson shape in different rapidity windows for double and single hemisphere. The multiplicities which are in Poisson-like shapes can be got according to the parameter /D and fitting qualities are compared with the results derived from the relevant theoretical models. The relationship between the Poisson-like shape and KNO scaling is discussed. The connection between the parameters expressing the deviation from the Poisson shape and non-independent particle emission and multiplicity correlation strength is analyzed. The 'shoulder structure' is observed in the central rapidity region and analyzed with multi-jets by using the JADE jet analysis algorithm
Directory of Open Access Journals (Sweden)
Francesco Caputo
2018-01-01
Full Text Available In this paper, a new methodology supporting the design of landing gears is proposed. Generally, a preliminary step is performed with simplified FE model, usually one-dimensional, to achieve the reaction forces involving each component during all aforementioned aircraft operations. Though this approach gives a valid support to the designer, it is characterized by several problems, such as the related approximations. So, it is important, by a numerical point of view, to develop an isostatic FE model equivalent to the real one. In fact, if the landing gear is modelled as hyperstatic, the static equilibrium equations are insufficient for determining the internal forces and reactions on each sub-component; so, the modelled material properties and geometries assume an increasing importance, which gets the model too approximating. The proposed methodology consists of achieving the reaction forces by means of multibody simulations, by overcoming such problems, since each component is modelled as rigid. In this paper, also a FE model for the investigation of the structural response is proposed. Aimed to Certification by Analysis purposes, the developed multibody and the FE models have been assessed against an experimental landing gear drop test carried out by Magnaghi Aeronautica S.p.A., according to the EASA CS 25 regulations
Hadronization of the quark-gluon plasma
International Nuclear Information System (INIS)
Mueller, B.; Sano, M.; Sato, H.; Schaefer, A.
1986-11-01
We construct a model for hadronization of the quark-gluon plasma, based on the relativistic coalescence model. We relate the coalescence amplitude to the one-particle Wigner function for quarks in the plasma. The relation between the Wigner function and the nucleon structure function is pointed out. We derive explicit expressions for the production of mesons and baryons in the framework of the relativistic harmonic oscillator model of hadronic structure. (author)
International Nuclear Information System (INIS)
Subudhi, M.; Bezler, P.
1984-01-01
Multiple independent support excitation time history formulations have been used to investigate simplified methods to predict the inertial (or dynamic) component of response as well as the pseudo-static (or static) component of response of secondary structures subjected to seismic excitations. For the dynamic component the independent response spectrum method is used with current industry practice for the modal and direction of excitation combinations being adopted and various procedures for the group combination and sequence being investigated. SRSS combination between support groups is found to yield satisfactory results. For the static component, support grouping by elevation for preliminary design followed by support grouping by attachment point for final design assure overall safety in the design
Directory of Open Access Journals (Sweden)
H. M. Chandima Chathuranga Somarathna
2016-05-01
Full Text Available In recent years, attention has been focused on elastomeric polymers as a potential retrofitting material considering their capability in contributing towards the impact resistance of various structural elements. A comprehensive understanding of the behavior and the morphology of this material are essential to propose an effective and feasible alternative to existing structural strengthening and retrofitting materials. This article presents the findings obtained from a series of experimental investigations to characterize the physical, mechanical, chemical and thermal behavior of eight types of palm-based polyurethane (PU elastomers, which were synthesized from the reaction between palm kernel oil-based monoester polyol (PKO-p and 4,4-diphenylmethane diisocyanate (MDI with polyethylene glycol (PEG as the plasticizer via pre-polymerization. Fourier transform infrared (FT-IR spectroscopy analysis was conducted to examine the functional groups in PU systems. Mechanical and physical behavior was studied with focus on elongation, stresses, modulus, energy absorption and dissipation, and load dispersion capacities by conducting hardness, tensile, flexural, Izod impact, and differential scanning calorimetry tests. Experimental results suggest that the palm-based PU has positive effects as a strengthening and retrofitting material against dynamic impulsive loadings both in terms of energy absorption and dissipation, and load dispersion. In addition, among all PUs with different plasticizer contents, PU2 to PU8 (which contain 2% to 8% (w/w PEG with respect to PKO-p content show the best correlation with mechanical response under quasi-static conditions focusing on energy absorption and dissipation and load dispersion characteristics.
Hadron correlations from recombination
Energy Technology Data Exchange (ETDEWEB)
Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
2005-01-01
Quark recombination is a successful model to describe the hadronization of a deconfined quark gluon plasma. Jet-like dihadron correlations measured at RHIC provide a challenge for this picture. We discuss how correlations between hadrons can arise from correlations between partons before hadronization. An enhancement of correlations through the recombination process, similar to the enhancement of elliptic flow is found. Hot spots from completely or partially quenched jets are a likely source of such parton correlations.
International Nuclear Information System (INIS)
Wiedner, Ulrich
2011-01-01
The new FAIR facility in Darmstadt has a broad program in the field of hadron and nuclear physics utilizing ion beams with unprecedented intensity and accuracy. The hadron physics program centers around the the high-energy storage ring HESR for antiprotons and the PANDA experiment that is integrated in it. The physics program includes among others topics like hadron spectroscopy in the charmonium mass region and below, hyperon physics, electromagnetic processes and charm in nuclei.
Density oscillations within hadrons
International Nuclear Information System (INIS)
Arnold, R.; Barshay, S.
1976-01-01
In models of extended hadrons, in which small bits of matter carrying charge and effective mass exist confined within a medium, oscillations in the matter density may occur. A way of investigating this possibility experimentally in high-energy hadron-hadron elastic diffraction scattering is suggested, and the effect is illustrated by examining some existing data which might be relevant to the question [fr
Spectroscopy of hadron resonances on the lattice
Energy Technology Data Exchange (ETDEWEB)
Bali, Gunnar; Burch, Tommy; Ehmann, Christian; Goeckeler, Meinulf; Hagen, Christian; Schaefer, Andreas [Institut fuer Theoretische Physik, Universitaet Regensburg, D-93040 Regensburg (Germany); Gattringer, Christof; Lang, Christian; Limmer, Markus; Mohler, Daniel [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria)
2009-07-01
The reproduction of the hadron mass spectrum from first principles is an important task for lattice QCD. While ground state spectroscopy, especially in the quenched approximation, is by now well understood, a clean extraction of excited hadron masses from a lattice QCD simulation still is a serious challenge. We discuss the relevant techniques for spectroscopy calculations on the lattice, in particular the variational technique which is needed for separating the different excited states from the ground state. Using this method we study three different sectors of the hadron spectrum. In the light quark sector we present hadron masses obtained from simulations with dynamical approximately chiral fermions, so-called Chirally Improved Fermions. For charmonium, we are able to extract masses for a number of excited states including ones with higher spin and exotic quantum numbers. The heavy-light hadron sector is investigated in the static-light approximation, i.e., the heavy quark is treated as infinitely heavy. Also here we are able to determine a large number of excitations.
DEFF Research Database (Denmark)
Danvy, Olivier; Damian, Daniel
2001-01-01
Starting from an operational specification of a translation from a structured to an unstructured imperative language, we point out how a compositional and context-insensitive translation gives rise to static chains of jumps. Taking an inspiration from the notion of continuation, we state a new co...
International Nuclear Information System (INIS)
Schwitters, R.F.
1975-01-01
A report is given of the knowledge obtained from SPEAR about hadron production in e + e - annihilation since the discovery of the new particles. Included are the SPEAR magnetic detector, the total cross sections, mean charged multiplicity and energy, inclusive momentum spectra, and hadron angular distribution
International Nuclear Information System (INIS)
Ernst, David J.
1992-01-01
At a Workshop on the Future of Hadron Facilities, held on 15-16 August at Los Alamos National Laboratory, several speakers pointed out that the US physics community carrying out fixed target experiments with hadron beam had not been as successful with funding as it deserved. To rectify this, they said, the community should be better organized and present a more united front
Statistical Hadronization and Holography
DEFF Research Database (Denmark)
Bechi, Jacopo
2009-01-01
In this paper we consider some issues about the statistical model of the hadronization in a holographic approach. We introduce a Rindler like horizon in the bulk and we understand the string breaking as a tunneling event under this horizon. We calculate the hadron spectrum and we get a thermal...
Energy Technology Data Exchange (ETDEWEB)
Ernst, David J.
1992-11-15
At a Workshop on the Future of Hadron Facilities, held on 15-16 August at Los Alamos National Laboratory, several speakers pointed out that the US physics community carrying out fixed target experiments with hadron beam had not been as successful with funding as it deserved. To rectify this, they said, the community should be better organized and present a more united front.
Firetube model and hadron-hadron collisions
International Nuclear Information System (INIS)
Nazareth, R.A.M.S.; Kodama, T.; Portes Junior, D.A.
1992-01-01
A new version of the fire tube model is developed to describe hadron-hadron collisions at ultrarelativistic energies. Several improvements are introduced in order to include the longitudinal expansion of intermediate fireballs, which remedies the overestimates of the transverse momenta in the previous version. It is found that, within a wide range of incident energies, the model describes well the experimental data for the single particle rapidity distribution, two-body correlations in the pseudo-rapidity, transverse momentum spectra of pions and kaons, the leading particle spectra and the K/π ratio. (author)
DEFF Research Database (Denmark)
Danvy, Olivier; Damian, Daniel
2001-01-01
Starting from an operational specification of a translation from a structured to an unstructured imperative language, we point out how a compositional and context-insensitive translation gives rise to static chains of jumps. Taking an inspiration from the notion of continuation, we state a new...... compositional and context-sensitive specification that provably gives rise to no static chains of jumps, no redundant labels, and no unused labels. It is defined with one inference rule per syntactic construct and operates in linear time and space on the size of the source program (indeed it operates in one...
International Nuclear Information System (INIS)
Strugalski, Z.
1981-01-01
Qualitative picture of high energy hadron-nucleus collision process, emerging from the analysis of experimental data, is presented. Appropriate description procedure giving a possibility of reproducing various characteristics of this process in terms of the data on elementary hadron-nucleon interaction is proposed. Formula reproducing hadron-nucleus collision cross sections is derived. Inelastic collision cross sections for pion-nucleus and proton-nucleus reactions at wide energy interval are calculated for Pb, Ag, and Al targets. A-dependence of cross sections for pion-nucleus and proton-nucleus collisions at nearly 50 GeV/c momentum were calculated and compared with existing experimental data. Energy dependence of cross sections for hadron-nucleus collisions is determined simply by energy dependence of corresponding cross sections for hadron-nucleon collisions; A-dependence is determined simply by nuclear sizes and nucleon density distributions in nuclei
International Nuclear Information System (INIS)
Tchangnwa Nya, F; Ayadim, A; Germain, Ph; Amokrane, S
2012-01-01
We examine the question of the accuracy of the static correlation functions used as input in the mode coupling theory (MCT) of non-ergodic states in binary mixtures. We first consider hard-sphere mixtures and compute the static pair structure from the Ornstein-Zernike equations with the Percus-Yevick closure and more accurate ones that use bridge functions deduced from Rosenfeld’s fundamental measures functional. The corresponding MCT predictions for the non-ergodicity lines and the transitions between multiple glassy states are determined from the long-time limit of the density autocorrelation functions. We find that while the non-ergodicity transition line is not very sensitive to the input static structure, up to diameter ratios D 2 /D 1 = 10, quantitative differences exist for the transitions between different glasses. The discrepancies with the more accurate closures become even qualitative for sufficiently asymmetric mixtures. They are correlated with the incorrect behavior of the PY structure at high size asymmetry. From the example of ultra-soft potential it is argued that this issue is of general relevance beyond the hard-sphere model. (paper)
High energy hadron spin-flip amplitude
International Nuclear Information System (INIS)
Selyugin, O.V.
2016-01-01
The high-energy part of the hadron spin-flip amplitude is examined in the framework of the new high-energy general structure (HEGS) model of the elastic hadron scattering at high energies. The different forms of the hadron spin-flip amplitude are compared in the impact parameter representation. It is shown that the existing experimental data of the proton-proton and proton-antiproton elastic scattering at high energy in the region of the diffraction minimum and at large momentum transfer give support in the presence of the energy-independent part of the hadron spin-flip amplitude with the momentum dependence proposed in the works by Galynskii-Kuraev. [ru
Directory of Open Access Journals (Sweden)
Dahaoui M.
2018-01-01
Full Text Available The static corrections are a necessary step in the sequence of the seismic processing. This paper presents a study of these corrections in the Essaouira basin. The main objective of this study is to calculate the static corrections by exploiting the seismic data acquired in the field to improve the deep structures imaging. It is to determine the roof and the basis of the superficial layers which constitute the weathered zone while calculating the delays of seismic wave’s arrivals in these layers. The purpose is to cancel the effect of the topography and the weathered zone, in order to avoid any confusion when the seismic and geological interpretation. The results obtained show the average values of the static corrections varying between - 127 and 282 ms (double time, with existence of high values by location, particularly in the Eastern and North-Eastern of the basin, which meant the presence of altered zone with irregular topography and whose thickness and speeds vary laterally. In effect the variations of velocities in the fifty meters from the surface may introduce significant anomalies in seismic refraction, with heavy consequences when the interpretation or the drilling establishment. These variations are mainly due to lateral changes in facies and variations in the formations thickness. The calculation of the static corrections, revealed high values at certain areas (East and North-East, which will enable us to better orient the future campaigns in these zones. It is therefore necessary to concentrate the seismic cores drillings and the small refraction seismic profiles by tightening the seismic lines meshes in order to have the maximum values of static corrections and thereafter a better imaging of the reflectors.
International Nuclear Information System (INIS)
Anon.
1987-01-01
With much particle physics research using particle beams to probe the behaviour of the quark constituents deep inside nucleons and other strongly interacting particles (hadrons), it is easy to overlook the progress being made through hadron spectroscopy – the search for and classification of rare particles – and the way it has increased our understanding of quark physics. One way of remedying this was to attend the stimulating and encouraging Hadron 87 meeting held earlier this year at the Japanese KEK Laboratory, where Jonathan Rosner from Chicago's Enrico Fermi Institute gave the concluding talk
Hadron accelerators in medicine
International Nuclear Information System (INIS)
Amaldi, U.
1996-01-01
The application of hadron accelerators (protons and light ions) in cancer therapy is discussed. After a brief introduction on the rationale for the use of heavy charged particles in radiation therapy, a discussion is given on accelerator technology and beam delivery systems. Next, existing and planned facilities are briefly reviewed. The Italian Hadron-therapy Project is then described in some detail, with reference ro both the National Centre for Oncological Hadron-therapy and the design of different types of compact proton accelerators aimed at introducing proton therapy in a large umber of hospitals. (author)
Energy Technology Data Exchange (ETDEWEB)
Anon.
1987-09-15
With much particle physics research using particle beams to probe the behaviour of the quark constituents deep inside nucleons and other strongly interacting particles (hadrons), it is easy to overlook the progress being made through hadron spectroscopy – the search for and classification of rare particles – and the way it has increased our understanding of quark physics. One way of remedying this was to attend the stimulating and encouraging Hadron 87 meeting held earlier this year at the Japanese KEK Laboratory, where Jonathan Rosner from Chicago's Enrico Fermi Institute gave the concluding talk.
International Nuclear Information System (INIS)
Shakib, H.; Dehghani Ashkezari, G.
2002-01-01
In this study, based on the equivalent static analysis method of the Iranian seismic code, an algorithm is presented to consider the soil-structure interaction (SSI) effects. Modifications of free field motion and structural properties like period and damping due to soil situation are considered in the proposed algorithm. An increase for fundamental period of structure and a modification (usually increase) for it's effective damping are observed. The increase of period is due to the flexibility of the soil foundation and modification of damping is due to the dissipating energy in soil. In order to propose the relative expressions in the presented algorithm, the soil-structure analyses of 8, 10, 13 and 16 stories frames are carried out. By considering the NEHRP soil-structure interaction algorithm and findings of soil-structure interaction analyses carried out in this study, the algorithm based on the equivalent static analysis method of the Iranian seismic building code to consider the effect of soil-structure interaction
Hard processes in hadronic interactions
International Nuclear Information System (INIS)
Satz, H.; Wang, X.N.
1995-01-01
Quantum chromodynamics is today accepted as the fundamental theory of strong interactions, even though most hadronic collisions lead to final states for which quantitative QCD predictions are still lacking. It therefore seems worthwhile to take stock of where we stand today and to what extent the presently available data on hard processes in hadronic collisions can be accounted for in terms of QCD. This is one reason for this work. The second reason - and in fact its original trigger - is the search for the quark-gluon plasma in high energy nuclear collisions. The hard processes to be considered here are the production of prompt photons, Drell-Yan dileptons, open charm, quarkonium states, and hard jets. For each of these, we discuss the present theoretical understanding, compare the resulting predictions to available data, and then show what behaviour it leads to at RHIC and LHC energies. All of these processes have the structure mentioned above: they contain a hard partonic interaction, calculable perturbatively, but also the non-perturbative parton distribution within a hadron. These parton distributions, however, can be studied theoretically in terms of counting rule arguments, and they can be checked independently by measurements of the parton structure functions in deep inelastic lepton-hadron scattering. The present volume is the work of Hard Probe Collaboration, a group of theorists who are interested in the problem and were willing to dedicate a considerable amount of their time and work on it. The necessary preparation, planning and coordination of the project were carried out in two workshops of two weeks' duration each, in February 1994 at CERn in Geneva andin July 1994 at LBL in Berkeley
Neutrino emissivity in the quark-hadron mixed phase of neutron stars
Energy Technology Data Exchange (ETDEWEB)
Spinella, William M. [Computational Science Research Center San Diego State University, San Diego, CA (United States); San Diego State University, Department of Physics, San Diego, CA (United States); Weber, Fridolin [San Diego State University, Department of Physics, San Diego, CA (United States); University of California San Diego, Center for Astrophysics and Space Sciences, La Jolla, CA (United States); Contrera, Gustavo A. [CONICET, Buenos Aires (Argentina); CONICET - Dept. de Fisica, UNLP, IFLP, La Plata (Argentina); Universidad Nacional de La Plata, Grupo de Gravitacion, Astrofisica y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, La Plata (Argentina); Orsaria, Milva G. [CONICET, Buenos Aires (Argentina); Universidad Nacional de La Plata, Grupo de Gravitacion, Astrofisica y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, La Plata (Argentina)
2016-03-15
Numerous theoretical studies using various equation of state models have shown that quark matter may exist at the extreme densities in the cores of high-mass neutron stars. It has also been shown that a phase transition from hadronic matter to quark matter would result in an extended mixed phase region that would segregate phases by net charge to minimize the total energy of the phase, leading to the formation of a crystalline lattice. The existence of quark matter in the core of a neutron star may have significant consequences for its thermal evolution, which for thousands of years is facilitated primarily by neutrino emission. In this work we investigate the effect a crystalline quark-hadron mixed phase can have on the neutrino emissivity from the core. To this end we calculate the equation of state using the relativistic mean-field approximation to model hadronic matter and a nonlocal extension of the three-flavor Nambu-Jona-Lasinio model for quark matter. Next we determine the extent of the quark-hadron mixed phase and its crystalline structure using the Glendenning construction, allowing for the formation of spherical blob, rod, and slab rare phase geometries. Finally we calculate the neutrino emissivity due to electron-lattice interactions utilizing the formalism developed for the analogous process in neutron star crusts. We find that the contribution to the neutrino emissivity due to the presence of a crystalline quark-hadron mixed phase is substantial compared to other mechanisms at fairly low temperatures (
Hadron physics at the new CW electron accelerators
International Nuclear Information System (INIS)
Burkert, V.D.
1990-01-01
Major trends of the physics program related to the study of hadron structure and hadron spectroscopy at the new high current, high duty cycle electron machines are discussed. It is concluded that planned experiments at these machines may have important impact on our understanding of the strong interaction by studying the internal structure and spectroscopy of the nucleon and lower mass hyperon states
International Nuclear Information System (INIS)
Ferbel, T.
1976-01-01
Recent experimental results from studies of hadron interactions at Fermilab are surveyed. Elastic, total and charge-exchange cross section measurements, diffractive phenomena, and inclusive production, using nuclear as well as hydrogen targets, are discussed in these lectures
Energy Technology Data Exchange (ETDEWEB)
NONE
2006-07-01
The following topics were ealt with: Hadron physics with proton and deuteron probes, physics projects with Georgian participation, spin physics with antiprotons and leptons, spin filtering experiments, ISTC projects, technical issues for FAIR. (HSI)
Hadron multiplicities at COMPASS
Energy Technology Data Exchange (ETDEWEB)
Du Fresne von Hohenesche, Nicolas [Institut fuer Kernphysik, Universitaet Mainz, Johann-Joachim-Becher-Weg 45, 55128 Mainz (Germany); Collaboration: COMPASS Collaboration
2014-07-01
Quark fragmentation functions (FF) D{sub q}{sup h}(z,Q{sup 2}) describe final-state hadronization of quarks q into hadrons h. The FFs can be extracted from hadron multiplicities produced in semi-inclusive deep inelastic scattering. The COMPASS collaboration has recently measured charged hadron multiplicities for identified pions and kaons using a 160 GeV/c muon beam impinging on an iso-scalar target. The data cover a large kinematical range and provide an important input for global QCD analyses of world data at NLO, aiming at the determination of FFs in particular in the strange quark sector. The newest results from COMPASS on pion and kaon multiplicities will be presented.
Garkushin, G. V.; Razorenov, S. V.; Krasnoveikin, V. A.; Kozulin, A. A.; Skripnyak, V. A.
2015-02-01
The elastic limit and tensile strength of deformed magnesium alloys Ma2-1 with different structures and textures were measured with the aim of finding a correlation between the spectrum of defects in the material and the resistance to deformation and fracture under quasi-static and dynamic loading conditions. The studies were performed using specimens in the as-received state after high-temperature annealing and specimens subjected to equal-channel angular pressing at a temperature of 250°C. The anisotropy of strength characteristics of the material after shock compression with respect to the direction of rolling of the original alloy was investigated. It was shown that, in contrast to the quasi-static loading conditions, under the shock wave loading conditions, the elastic limit and tensile strength of the magnesium alloy Ma2-1 after equal-channel angular pressing decrease as compared to the specimens in the as-received state.
International Nuclear Information System (INIS)
Dearien, J.A.; Uldrich, E.D.
1975-01-01
1 - Description of problem or function: The code STRAP (Structural Analysis Package) was developed to analyze the response of structural systems to static and dynamic loading conditions. STRAP-S solves for the displacements and member forces of structural systems under static loads and temperature gradients. STRAP-D will solve numerically a given structural dynamics problem. 2 - Method of solution: STRAP-S generates the stiffness matrix of a structure by the finite element method and solves the resulting equations for structural displacements and member forces. STRAP-D generates the stiffness matrix, solves for eigenvalues and eigenvectors, uncouples and solves the series of second-order ordinary differential equations, and then calculates and plots the requested member forces. 3 - Restrictions on the complexity of the problem: STRAP-S maxima: 250 degrees of freedom, 100 members; STRAP-D maxima: 100 degrees of freedom, 80 time-steps in the forcing function input
Hadronic production of glueballs
International Nuclear Information System (INIS)
Lindenbaum, S.J.
1983-01-01
Local Gauge Invariance of SU(3)/sub c/ and color confinement would require that the only hadrons in the world be glueballs. However, when we add the quarks and obtain QCD it is experimentally clear that quark built states mask the expected glueballs. Thus discovery of glueballs is essential for the viability of QCD. Papers presented at the 1983 International Europhysics Conference on High Energy Physics on the hadronic production of glueballs and searches for glueballs are reviewed
Banfi, Andrea
2016-01-01
Jet physics is an incredibly rich subject detailing the narrow cone of hadrons and other particles produced by the hadronization of a quark or gluon in a particle physics or heavy ion experiment. This book is a general overview of jet physics for scientists not directly involved in the field. It presents the basic experimental and theoretical problems arising when dealing with jets, and describing the solutions proposed in recent years.
Researches at hadron experiment facility
International Nuclear Information System (INIS)
Sawada, Shinya
2006-01-01
Some of the nuclear, hadron and elementary particle experiments proposed to hadron experiment facility to use the extracted slow proton beam at J-PARC are overviewed. Characteristic feature of the facility is the secondary beam obtained from the intense proton beam. Nuclear hadron physics experiments and kaon rare decay experiments are presented here as the typical ones. Hypernuclear spectroscopy with S=-2 state is expected to be started as soon as the beam becomes available. The kaon bound systems not only with three nucleons like K-pnn but also more numerous like Li and Be are to be studied systematically. Bound states of two kaons using (K - , K + ) reaction will be challenged. Pentaquark will be searched for and its properties will be studied if it really exists. Nuclear structure studies from the view point of large Bjorken x are planned to be studied by irradiating hydrogen, deuteron or heavier targets with primary proton beam and analyzing generated muon pairs. Properties of vector mesons in nuclear matter are to be studied with the primary beam. Neutral kaon rare decay will be investigated to study CP nonconservation. Large progress of elementary particle physics is anticipated by using the intense proton beam at J-PARC. (S. Funahashi)
Quantum chromodynamic quark model study of hadron and few hadron systems
International Nuclear Information System (INIS)
Ji, Chueng-Ryong.
1990-10-01
This report details research progress and results obtained during the five month period July 1, 1990 to November 30, 1990. The research project, entitled ''Quantum Chromodynamic Quark Model Study of Hadron and Few Hadron Systems,'' is supported by grant FG05-90ER40589 between North Carolina State University and the United States Department of Energy. This is a research program addressing theoretical investigations of hadron structure and reactions using quantum chromodynamic quark models. The new, significant research results are briefly summarized in the following sections
Total cross section for e+e- → hadrons and its associated spectroscopy at SPEAR
International Nuclear Information System (INIS)
Lynch, H.L.
1976-05-01
The relation between the cross section for e + e - → hadrons and pp → e + e - + hadrons is briefly discussed. The structure of these cross sections is described in detail and its implications pointed out. 8 refs
Artificial Neural Networks For Hadron Hadron Cross-sections
International Nuclear Information System (INIS)
ELMashad, M.; ELBakry, M.Y.; Tantawy, M.; Habashy, D.M.
2011-01-01
In recent years artificial neural networks (ANN ) have emerged as a mature and viable framework with many applications in various areas. Artificial neural networks theory is sometimes used to refer to a branch of computational science that uses neural networks as models to either simulate or analyze complex phenomena and/or study the principles of operation of neural networks analytically. In this work a model of hadron- hadron collision using the ANN technique is present, the hadron- hadron based ANN model calculates the cross sections of hadron- hadron collision. The results amply demonstrate the feasibility of such new technique in extracting the collision features and prove its effectiveness
Tereshchenko, N. A.; Tabatchikova, T. I.; Yakovleva, I. L.; Makovetskii, A. N.; Shander, S. V.
2017-07-01
The static cracking resistance of a number of welded joints made from pipe steels of K60 strength class has been determined. It has been established that the deformation parameter CTOD varies significantly at identical parameters of weldability of steels. The character of fracture has been investigated and the zone of local brittleness of welded joints has been studied. It has been shown that the ability of a metal to resist cracking is determined by the austenite grain size and by the bainite morphology in the region of overheating in the heat-affected zone of a welded joint.
Energy Technology Data Exchange (ETDEWEB)
Mote, Kaustubh R. [University of Minnesota, Department of Chemistry (United States); Gopinath, T. [University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics (United States); Veglia, Gianluigi, E-mail: vegli001@umn.edu [University of Minnesota, Department of Chemistry (United States)
2013-10-15
The low sensitivity inherent to both the static and magic angle spinning techniques of solid-state NMR (ssNMR) spectroscopy has thus far limited the routine application of multidimensional experiments to determine the structure of membrane proteins in lipid bilayers. Here, we demonstrate the advantage of using a recently developed class of experiments, polarization optimized experiments, for both static and MAS spectroscopy to achieve higher sensitivity and substantial time-savings for 2D and 3D experiments. We used sarcolipin, a single pass membrane protein, reconstituted in oriented bicelles (for oriented ssNMR) and multilamellar vesicles (for MAS ssNMR) as a benchmark. The restraints derived by these experiments are then combined into a hybrid energy function to allow simultaneous determination of structure and topology. The resulting structural ensemble converged to a helical conformation with a backbone RMSD {approx}0.44 A, a tilt angle of 24 Degree-Sign {+-} 1 Degree-Sign , and an azimuthal angle of 55 Degree-Sign {+-} 6 Degree-Sign . This work represents a crucial first step toward obtaining high-resolution structures of large membrane proteins using combined multidimensional oriented solid-state NMR and magic angle spinning solid-state NMR.
The QCD model of hadron cores of the meson theory
International Nuclear Information System (INIS)
Pokrovskii, Y.E.
1985-01-01
It was shown that in the previously proposed QCD model of hadron cores the exchange and self-energy contributions of the virtual quark-antiquark-gluon cloud on the outside of a bag which radius coincides with the hardon core radius of the meson theory (∼ 0.4 Fm) have been taken into account at the phenomenological level. Simulation of this cloud by the meson field results in realistic estimations of the nucleon's electroweak properties, moment fractions carried by gluons, quarks, antiquarks and hadron-hadron interaction cross-sections within a wide range of energies. The authors note that the QCD hadron core model proposed earlier not only realistically reflects the hadron masses, but reflects self-consistently main elements of the structure and interaction of hadrons at the quark-gluon bag radius (R - 0.4Fm) being close to the meson theory core radius
Lifetimes of charmed hadrons revisited. Facts and fancy
International Nuclear Information System (INIS)
Blok, B.
1994-01-01
The problem of the hierarchy of lifetimes of charmed hadrons is reviewed. The QCD-based theory of pre asymptotic effects in inclusive weak decays dating back to the beginning of the eighties is now entering its mature phase. Combining recent and old results it is shown that the observed hierarchy reflects most intimate features of the hadronic structure. The problem of a wide spread of lifetimes of charmed hadrons is addressed. A number of predictions is given for the hierarchy of lifetimes in the family of the beautiful hadrons. (author). 29 refs., 3 figs., 1 tab
Mohamad, M. L.; Rahman, M. T. A.; Khan, S. F.; Basha, M. H.; Adom, A. H.; Hashim, M. S. M.
2017-10-01
The main purpose of this study is to make improvement for the UniMAP Automotive Racing Team car chassis which has several problems associated with the chassis must be fixed and some changes are needed to be made in order to perform well. This study involves the process of designing three chassis that are created based on the rules stated by FSAE rules book (2017/2018). The three chassis will undergo analysis test that consists of five tests which are main roll hoop test, front roll hoop test, static shear, side impact, static torsional loading and finally one of them will be selected as the best design in term of Von Mises Stress and torsional displacement. From the results obtained, the new selected chassis design which also declared as the new improved design poses the weight of 27.66 kg which was decreased by 16.7% from the existing chassis (32.77 kg). The torsional rigidity of the improved chassis increased by 37.74%.
Energy Technology Data Exchange (ETDEWEB)
Berenguer, J.
2014-07-01
The assembly of a mechanical structure used for a semi-digital hadronic calorimeter prototype, conceived and developed by the SDHCAL group within the CALICE collaboration, is presented in this note. CALICE is an international R and D collaboration dedicated to the development of calorimeters for future linear collider experiments. The design, assembly and quality control of this mechanical structure were entirely carried out at CIEMAT. This document contains a description of the prototype and its detectors, focusing on the design and assembly of the mechanical structure, which acts as well as the calorimeter absorber.. (Author)
2009-01-01
The CERN Dragon Boat team – the Hadron Dragons – achieved a fantastic result at the "Paddle for Cancer" Dragon Boat Festival at Lac de Joux on 6 September. CERN Hadron Dragons heading for the start line.Under blue skies and on a clear lake, the Hadron Dragons won 2nd place in a hard-fought final, following top times in the previous heats. In a close and dramatic race – neck-and-neck until the final 50 metres – the local Lac-de-Joux team managed to inch ahead at the last moment. The Hadron Dragons were delighted to take part in this festival. No one would turn down a day out in such a friendly and fun atmosphere, but the Dragons were also giving their support to cancer awareness and fund-raising in association with ESCA (English-Speaking Cancer Association of Geneva). Riding on their great success in recent competitions, the Hadron Dragons plan to enter the last Dragon Boat festival of 2009 in Annecy on 17-18 October. This will coincide with t...
Study of the hadronisation process from single hadron and hadron-pair production in SIDIS at COMPASS
Makke, Nour
2014-01-01
Hadron production in hard scattering reactions is described by the hadronization mechanism which combines quarks into final-state hadrons. Within the theoretical framework of leading-twist collinear QCD, the cross section for hadron production in semi-inclusive deep-inelastic scattering can be factorized into a hard scattering cross section describing the hard interaction at the quark level calculable in perturbative QED, and non-perturbative universal functions: parton distribution functions which reflect the quark structure of initial-state hadrons and collinear fragmentation functions which encode details on the hadronization process. In the last decades, a major effort has been achieved on theoretical and experimental levels and allowed to constraint, with very high precision, parton distribution functions except strange quark distribution, which still carries large uncertainties. Fragmentation functions, however, remain at a very preliminary stage of study with a growing interest in a more accurate and p...
The theory of hadronic systems
International Nuclear Information System (INIS)
Gibbs, W.R.
1995-01-01
This report briefly discusses progress on the following topics: isospin breaking in the pion-nucleon system; subthreshold amplitudes in the πN system; neutron-proton charge-exchange; transparency in pion production; energy dependence of pion DCX; direct capture of pions into deeply bound atomic states; knock out of secondary components in the nucleus; radii of neutron distributions in nuclei; the hadronic double scattering operator; pion scattering and charge exchange from polarized nuclei; pion absorption in nuclei; modification of nucleon structure in nuclei; and antiproton annihilation in nuclei
Palano, Antimo
2018-01-01
The LHCb experiment is designed to study the properties and decays of heavy ﬂavored hadrons produced in pp collisions at the LHC. The data collected in the LHC Run I enables precision spectroscopy studies of beauty and charm hadrons. The latest results on spectroscopy of conventional and exotic hadrons are reviewed. In particular the discovery of the ﬁrst charmonium pentaquark states in the $J/\\psi p$ system, the possible existence of four-quark states decaying to $J/\\psi \\phi$ and the conﬁrmation of resonant nature of the $Z_c(4430)^−$ mesonic state are discussed. In the sector of charmed baryons, the observation of ﬁve new $\\Omega_c$ states, the observation of the $\\Xi^+_{cc}$ and the study of charmed baryons decaying to $D^0 p$ are presented.
High energy hadron-hadron collisions. Annual progress report
International Nuclear Information System (INIS)
Chou, T.T.
1979-03-01
Work on high energy hadron-hadron collisions in the geometrical model, performed under the DOE Contract No. EY-76-S-09-0946, is summarized. Specific items studied include the behavior of elastic hadron scatterings at super high energies and the existence of many dips, the computation of meson radii in the geometrical model, and the hadronic matter current effects in inelastic two-body collisions
Electron and gamma-ray irradiated NTD Si p-n structures static and dynamic parameters trade-off
International Nuclear Information System (INIS)
Marchenko, I.G.; Zhdanovich, N.E.; Karas', V.I.
2005-01-01
The comparison of different radiation defects types influence on static and dynamic parameters trade-off of power diodes fabricated on neutron-transmutation doped silicon have been fulfilled. Various defects sets were introduced utilizing electron irradiation (E=6 MeV), gamma-ray Co 60 irradiation and electron irradiation and subsequent annealing at temperature 700 degrees centigrade. It is established that optimal trade-of between forward voltage drop and operation speed is achieved in case of electron irradiation and annealing. In this case recombination process is governed by defect with energy level near middle of forbidden gap (E c -0.53 eV). The results obtained indicate on possibility of using these defect recombination properties for speed control in production of power fast high-voltage devices on the base of neutron-transmutation doped silicon. (authors)
Energy Technology Data Exchange (ETDEWEB)
Rakhecha, Shalu, E-mail: shalurakhecha@yahoo.com; Vyas, P. R.; Gohel, V. B. [Department of Physics, School of Sciences, Gujarat University, Ahmedabad - 380009, Gujarat (India); Bhatt, N. K. [Department of Physics, Sardar Patel University, Vallabh Vidyanagar - 388120, Gujarat (India)
2016-05-06
In the present communication, we have computed static and dynamic properties (binding energy-E, bulk modulus-B and second moment- <ω{sup 2}>) as well as first order pressure induced phase transition (FCC-BCC) using local form of pseudopotential for Calcium and Strontium. The form of pseudopotential used for the computation is directly extracted from Generalized Pseudopotential Theory (GPT) which contains three parameters (r{sub c}, r{sub d} and β). We have suggested a simple method using which pseudopotential is determined by single parameter (β). Our computed results for binding energy and bulk modulii are in excellent agreement with experimental findings and are better than other theoretical results. The present study confirms that s-d hybridization is accounted properly in the presently used pseudopotential and can be extended for the study of lattice mechanical properties of these metals.
International Nuclear Information System (INIS)
Quigg, C.
1982-11-01
The subject of hadron jet studies, to judge by the work presented at this workshop, is a maturing field which is still gathering steam. The very detailed work being done in lepton-lepton and lepton-hadron collisions, the second-generation measurements being carried out at Fermilab, the CERN SPS, and the ISR, and the very high energy hard scatterings being observed at the CERN Collider all show enormous promise for increased understanding. Perhaps we shall yet reach that long-sought nirvana in which high-p/sub perpendicular/ collisions become truly simple
International Nuclear Information System (INIS)
Ogava, S.; Savada, S.; Nakagava, M.
1983-01-01
Composite models of hadrons are considered. The main attention is paid to the Sakata, S model. In the framework of the model it is presupposed that proton, neutron and Λ particle are the fundamental particles. Theoretical studies of unknown fundamental constituents of a substance have led to the creation of the quark model. In the framework of the quark model using the theory of SU(6)-symmetry the classification of mesons and baryons is considered. Using the quark model relations between hadron masses, their spins and electromagnetic properties are explained. The problem of three-colour model with many flavours is briefly presented
High intensity hadron accelerators
International Nuclear Information System (INIS)
Teng, L.C.
1989-05-01
This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics
International Nuclear Information System (INIS)
Anon.
1987-01-01
'Hadron facilities' – high intensity (typically a hundred microamps), medium energy (30-60 GeV) machines producing intense secondary beams of pions, kaons, etc., are being widely touted as a profitable research avenue to supplement what is learned through the thrust for higher and higher energies. This interest was reflected at an International Workshop on Hadron Facility Technology, held in Santa Fe, New Mexico. As well as invited talks describing the various projects being pushed in the US, Europe and Japan, the meeting included working groups covering linacs, beam dynamics, hardware, radiofrequency, polarized beams and experimental facilities
Large transverse momenta phenomena in hadron-hadron collisions
International Nuclear Information System (INIS)
McCubbin, N.A.
1981-05-01
The production of particles with large transverse momentum in high energy hadron-hadron collisions is reviewed. The emphasis is placed on the experimental results. These results are discussed in terms of present theoretical ideas on interactions between hadronic constituents, but no attempt is made to review the theoretical work in a comprehensive manner. (author)
Directory of Open Access Journals (Sweden)
Olaf Andersen
2016-05-01
Full Text Available Rigid metallic fiber structures made from a variety of different metals and alloys have been investigated mainly with regard to their functional properties such as heat transfer, pressure drop, or filtration characteristics. With the recent advent of aluminum and magnesium-based fiber structures, the application of such structures in light-weight crash absorbers has become conceivable. The present paper therefore elucidates the mechanical behavior of rigid sintered fiber structures under quasi-static and dynamic loading. Special attention is paid to the strongly anisotropic properties observed for different directions of loading in relation to the main fiber orientation. Basically, the structures show an orthotropic behavior; however, a finite thickness of the fiber slabs results in moderate deviations from a purely orthotropic behavior. The morphology of the tested specimens is examined by computed tomography, and experimental results for different directions of loading as well as different relative densities are presented. Numerical calculations were carried out using real structural data derived from the computed tomography data. Depending on the direction of loading, the fiber structures show a distinctively different deformation behavior both experimentally and numerically. Based on these results, the prevalent modes of deformation are discussed and a first comparison with an established polymer foam and an assessment of the applicability of aluminum fiber structures in crash protection devices is attempted.
Hadron Therapy for Cancer Treatment
International Nuclear Information System (INIS)
Lennox, Arlene
2003-01-01
The biological and physical rationale for hadron therapy is well understood by the research community, but hadron therapy is not well established in mainstream medicine. This talk will describe the biological advantage of neutron therapy and the dose distribution advantage of proton therapy, followed by a discussion of the challenges to be met before hadron therapy can play a significant role in treating cancer. A proposal for a new research-oriented hadron clinic will be presented.
Diffractive production and hadron structure
International Nuclear Information System (INIS)
Nussinov, S.; Szwed, J.
1979-01-01
Analysis of diffractive production on nuclei implied cross sections of the diffractively produced system on nucleons which are smaller than the corresponding projectile nucleon cross sections. A natural explanation for this feature is provided in the Good-Walker coherent production formalism. A specific realization of the Good-Walker formalism stated in terms of quarks and connecting electric flux tubes and some ensuing consequences are also discussed briefly. (Auth.)
Hadron physics from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Schaefer, Andreas [Regensburg Univ. (Germany). Inst. for Theoretical Physics
2016-11-01
with the required precision. However, quantum field theory has a very important fundamental property, which allows to make progress: When the variable ''time'' is analytically continued to imaginary time (in the sense of square root of minus one) it gets mapped onto thermodynamics and statistics and questions in quantum field theory are transformed into purely statistical problems, which can be solved numerically by Monte Carlo techniques. While there might be more to it, this can be seen as just a mathematical trick. This trick does not only make numerical simulations of quantum field theories possible, but it solves at the same time the problem alluded to above: Within QCD any quark-gluon model which is simple enough that one can use it for practical calculations, fails to describe a real hadron. More precisely a simple quark-gluon state, which can easily be described within QCD corresponds to an infinitely complicated superposition of hadronic states. However, if such a superposition is propagated in imaginary time in the right manner all components except the lowest mass physical hadron, e.g. the proton, get exponentially suppressed. Thus the exact many particle wave function of the physical proton is obtained with which one can then calculate all physical quantities one is interested in, with one constraint: Because time has lost its meaning, only time-independent quantities can be obtained. Consequently, Lattice QCD has nearly always to be combined with real time treatments, most prominently perturbative QCD, to obtain physical predictions. The schematic structure of hadron structure lattice calculations is illustrated. Because source, sink and matrix element define three points in space-time such amplitudes are called ''3-point functions''.The Greens function on the lattice is just the inverse of a large sparse matrix. This inversion is one of the computationally most expensive tasks in lattice QCD calculations. To
Hadronization of dense partonic matter
Energy Technology Data Exchange (ETDEWEB)
Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
2006-12-15
The parton recombination model has turned out to be a valuable tool to describe hadronization in high-energy heavy-ion collisions. I review the model and revisit recent progress in our understanding of hadron correlations. I also discuss higher Fock states in the hadrons, possible violations of the elliptic flow scaling and recombination effects in more dilute systems.
International Nuclear Information System (INIS)
Johnson, R.C.
1980-01-01
High energy and small momentum transfer 2 'yields' 2 hadronic scattering processes are described in the physical framework of particle exchange. Particle production in high energy collisions is considered with emphasis on the features of inclusive reactions though with some remarks on exclusive processes. (U.K.)
Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Ariztizabal, F; Chmeissani, M; Crespo, J M; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Gaitan, V; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Engelhardt, A; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Markou, C; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wiedenmann, W; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Bardadin-Otwinowska, Maria; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Saadi, F; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Kyriakis, A; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Passalacqua, L; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Delfino, M C; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Pepé-Altarelli, M; Dorris, S J; Halley, A W; ten Have, I; Knowles, I G; Lynch, J G; Morton, W T; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Smith, M G; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Braun, O; Geweniger, C; Graefe, G; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Colling, D J; Dornan, Peter J; Konstantinidis, N P; Moneta, L; Moutoussi, A; Nash, J; San Martin, G; Sedgbeer, J K; Stacey, A M; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Raab, J; Renk, B; Sander, H G; Wanke, R; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Thulasidas, M; Nicod, D; Payre, P; Rousseau, D; Talby, M; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Brown, D; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wolf, G; Alemany, R; Boucrot, J; Callot, O; Cordier, A; Courault, F; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Musolino, G; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Abbaneo, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Triggiani, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Mir, L M; Perrodo, P; Strong, J A; Bertin, V; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Edwards, M; Maley, P; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Cartwright, S L; Combley, F; Dawson, I; Köksal, A; Letho, M; Newton, W M; Rankin, C; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G
1996-01-01
From 64492 selected \\tau-pair events, produced at the Z^0 resonance, the measurement of the tau decays into hadrons from a global analysis using 1991, 1992 and 1993 ALEPH data is presented. Special emphasis is given to the reconstruction of photons and \\pi^0's, and the removal of fake photons. A detailed study of the systematics entering the \\pi^0 reconstruction is also given. A complete and consistent set of tau hadronic branching ratios is presented for 18 exclusive modes. Most measurements are more precise than the present world average. The new level of precision reached allows a stringent test of \\tau-\\mu universality in hadronic decays, g_\\tau/g_\\mu \\ = \\ 1.0013 \\ \\pm \\ 0.0095, and the first measurement of the vector and axial-vector contributions to the non-strange hadronic \\tau decay width: R_{\\tau ,V} \\ = \\ 1.788 \\ \\pm \\ 0.025 and R_{\\tau ,A} \\ = \\ 1.694 \\ \\pm \\ 0.027. The ratio (R_{\\tau ,V} - R_{\\tau ,A}) / (R_{\\tau ,V} + R_{\\tau ,A}), equal to (2.7 \\pm 1.3) \\ \\%, is a measure of the importance of Q...
Eytier, Jean-Louis
2009-01-01
Qu'aurait-il proposé comme solutions face aux déboires du LHC, le grand collisionneur du hadrons du CERN, arrêté peu après son démarrage à l'automne 2008? Lucien Edmond André Montanet était un des grands de la physique des particules. (2 pages)
Indian Academy of Sciences (India)
manifestly the symmetries of the underlying theory of strong interactions, i.e. ..... Note that such a picture, in which the self-energies of hadrons are generated by ..... An experimental verification of this prediction would be a major step forward in.
International Nuclear Information System (INIS)
Ilgenfritz, E.M.; Kripfganz, J.; Moehring, H.J.
1977-01-01
The analytical treatment of hadronic decay cascades within the framework of the statistical bootstrap model is demonstrated on the basis of a simple variant. Selected problems for a more comprehensive formulation of the model such as angular momentum conservation, quantum statistical effects, and the immediate applicability to particle production processes at high energies are discussed in detail
Hirstius, Andreas
2008-01-01
Plans for dealing with the torrent of data from the Large Hadron Collider's detectors have made the CERN particle-phycis lab, yet again, a pioneer in computing as well as physics. The author describes the challenges of processing and storing data in the age of petabyt science. (4 pages)
2007-01-01
"In the spring 2008, the Large Hadron Collider (LHC) machine at CERN (the European Particle Physics laboratory) will be switched on for the first time. The huge machine is housed in a circular tunnel, 27 km long, excavated deep under the French-Swiss border near Geneva." (1,5 page)
Evidences for two scales in hadrons
International Nuclear Information System (INIS)
Kopeliovich, B. Z.; Potashnikova, I. K.; Schmidt, Ivan; Povh, B.
2007-01-01
Some unusual features observed in hadronic collisions at high energies can be understood assuming that gluons in hadrons are located within small spots occupying only about 10% of the hadrons' area. Such a conjecture about the presence of two scales in hadrons helps to explain the following: why diffractive gluon radiation is so suppressed; why the triple-Pomeron coupling shows no t dependence; why total hadronic cross sections rise so slowly with energy; why diffraction cones shrink so slowly, and why α P ' R ' ; why the transition from hard to soft regimes in the structure functions occurs at rather large Q 2 ; why the observed Cronin effect at collider energies is so weak; why hard reactions sensitive to primordial parton motion (direct photon, Drell-Yan dileptons, heavy flavors, back-to-back dihadrons, seagull effect, etc.) demand such a large transverse momenta of the projectile partons, which is not explained by next-to-leading order calculations; why the onset of nuclear shadowing for gluons is so delayed compared to quarks; and why shadowing is so weak
The Ways of Four-Quark Hadrons
CERN. Geneva
2014-01-01
Ten years after the discovery of the X(3872) we can assert that a number of exotic four-quark hadrons with hidden charm and beauty have been discovered, the most recent, Z(3900), found by BES in 2013, being among the top-striking ones. However, ten years have not been enough to dispel the controversy about their inner structure, with two body hadron molecules and compact multiquark states being the withstanding antipodal models. In this seminar I will review the status of the field, presenting both the experimental facts and the theoretical pictures attempting to interpret them.
A rotating bag model for hadrons. 2
International Nuclear Information System (INIS)
Iwasaki, Masaharu
1994-01-01
The MIT bag model is modified in order to describe rotational motion of hadrons. It has a kind of 'diatomic molecular' structure; The rotational excitation of the MIT bag is described by the polarized two colored sub-bags which are connected with each other by the gluon flux. One sub-bag contains a quark and the other has an antiquark for mesons. For baryons, the latter sub-bag contains the remaining two quarks instead of the antiquark. The Regge trajectories of hadrons are explained qualitatively by our new model with the usual MIT bag parameters. In particular the Regge slopes are reproduced fairly well. It is also pointed out that the gluon flux plays an important role in the rotational motion of hadrons. (author)
Gluon bremsstrahlung and elastic scattering of hadrons
International Nuclear Information System (INIS)
Povh, B.
2001-01-01
The differential and the total cross sections in high energy hadron-proton interactions give a beautiful insight in the low Q 2 structure of the nucleon. The cross section is composed of two parts: a large energy independent part corresponding to the interaction of the valence quark with the target without gluon radiation and an energy dependent part caused by gluon bremsstrahlung. The gluons are located at small transverse distances of about 0.3 fm from the valence quarks. The model with two scales, the size of the hadron (R 2 ∼ 1 fm 2 ) and the size of the gluonic cloud (r 0 2 ∼ 0.1 fm 2 ), correctly predicts the total and the differential cross sections and the behaviour of diffractive dissociation in hadronic and deep inelastic events. (orig.)
Hadronization of QCD and effective interactions
International Nuclear Information System (INIS)
Frank, M.R.
1994-01-01
An introductory treatment of hadronization through functional integral calculus and bifocal Bose fields is given. Emphasis is placed on the utility of this approach for providing a connection between QCD and effective hadronic field theories. The hadronic interactions obtained by this method are nonlocal due to the QCD substructure, yet, in the presence of an electromagnetic field, maintain the electromagnetic gauge invariance manifest at the quark level. A local chiral model which is structurally consistent with chiral perturbation theory is obtained through a derivative expansion of the nonlocalities with determined, finite coefficients. Tree-level calculations of the pion form factor and π - π scattering, which illustrate the dual constituent-quark-chiral-model nature of this approach, are presented
Quarks for hadrons and leptons
International Nuclear Information System (INIS)
Lopes, J.L.
1975-01-01
The simplest, naive, model for a unified description of leptons and hadrons consists in postulating, besides the usual quarks p, n, lambda a fourth quark, with very heavy mass and very high binding to pairs like anti p n and anti p lambda. In a SU(4) scheme the fourth quark has a quantum number charm which may be taken as proportional to the lepton number. Muons would be distinguished from electrons by the occurence of a lambda-quark instead of a n-quark in their structure. The forces among these quarks would have to be such as to give leptons an almost point-like structure at the experimentally known energies as well as absence of strong interactions at these energies. However, one would expect the display of strong interactions by leptons at extremely high energies [pt
Symmetries and aggregates of quarks as constituents of hadrons
International Nuclear Information System (INIS)
Kibler, M.
1982-07-01
The interest of the Lie algebra of the group SU(n) for the classification of hadrons and the description of some of their static properties is emphasized for n=3, 4, 6, 8. The cases n=3 and 4 allow to introduce the quark flavors (u,d,s,) and (u,d,c,s), respectively, and the consideration of the spin of hadrons leads to the chain SU(2m) contains SU(m) x SU(2). The hadrons are described as bound states or aggregates of quarks of type quark-quark-quark for baryons and quark-antiquark for mesons. The Pauli exclusion principle applied to the three-quark baryons requires the introduction of a new quantum number, the color: each flavor of quark then comes in three colors
National Research Council Canada - National Science Library
Pastore, C. M
1999-01-01
.... Some specific applications of the developed analysis are shown on the examples of transverse dynamic bending of simply supported laminated plate and 3D contact analysis for a multi-brick structure...
Lavender, Gemma
2018-01-01
What is the universe made of? How did it start? This Manual tells the story of how physicists are seeking answers to these questions using the worlds largest particle smasher the Large Hadron Collider at the CERN laboratory on the Franco-Swiss border. Beginning with the first tentative steps taken to build the machine, the digestible text, supported by color photographs of the hardware involved, along with annotated schematic diagrams of the physics experiments, covers the particle accelerators greatest discoveries from both the perspective of the writer and the scientists who work there. The Large Hadron Collider Manual is a full, comprehensive guide to the most famous, record-breaking physics experiment in the world, which continues to capture the public imagination as it provides new insight into the fundamental laws of nature.
International Nuclear Information System (INIS)
Yamazaki, Toshimitsu
1990-01-01
The Japanese Hadron Project (JHP) is aimed at producing various kinds of unstable secondary beams based on high-intensity protons from a new accelerator complex. The 1 GeV protons, first produced from a 1 GeV linac, are transferred to a compressor/stretcher ring, where a sharply-pulsed beam or a stretched continuous beam will be produced. The pulsed beam will be used for a pulsed muon source (M arena) and a spallation neutron source (N arena). A part of the proton beam will be used to produce unstable nuclei, which will be accelerated to several MeV/nucleon (E arena). The purpose and impact of JHP will be described in view of future applications of hadronic beams to nuclear energy and material science. (author)
International Nuclear Information System (INIS)
Hansl-Kozanecka, T.
1992-01-01
In this set of lectures the author examines phenomenological aspects of quantum chromodynamics (QCD) which are relevant for lepton-hadron, electron-positron, and hadron-hadron collisions. He points how the strength of the strong coupling constant, αs, makes QCD calculations converge much more slowly in powers of αs, and missing higher order terms must be carefully estimated. The most stringent test of QCD can be performed in deep inelastic lepton scattering and in e + e - annihilation. In deep inelastic scattering the virtual γ or W/Z are used as a probe of the nucleon structure. They couple to quarks, not gluons. Only the incoming and outgoing lepton have to be measured. The hadronic fluid state does not have to be analyzed. In e + e - annihilation the virtual γ or Z 0 decays to lepton and quark pairs. The branching ratio into quarks is a counter for the number of colours available, the detailed structure of the final state reflects the radiation of gluons as the initial quark-antiquark separate from each other. Quarks and gluons are observed here, though in the presence of hadron formation. Hard hadron-hadron, or parton-parton collisions provide cross sections dominated by the gluon component, which is only weakly measured in deep inelastic collisions. Recent experimental results in these three areas are reviewed, and compared to QCD calculations. Scaling violations and analysis of structure functions in deep inelastic scattering are reviewed. QCD in e + e - branching to hadrons is reviewed near the Z 0 resonance, and a number of cross sections and jet related properties which can be calculated as a function of the single parameter αs are reviewed. Hadron-hadron collisions are reviewed for three processes; jet production, direct photon production, and high p perpendicular W/Z boson production
International Nuclear Information System (INIS)
Roser, T.
1994-01-01
There were four sessions on Hadron Beams and Accelerators with 7 talks on Siberian Snakes and spin rotators, 3 talks on polarization build-up of unpolarized beams in storage rings and 5. 9, and 3 talks on low, medium, and high energy polarimeters, respectively. In this paper I will briefly describe a few highlights from these sessions, giving emphasis to topics which I think will play an important role in the future
International Nuclear Information System (INIS)
Roser, T.
1995-01-01
There were four sessions on Hadron Beams and Accelerators with 7 talks on Siberian Snakes and spin rotators, 3 talks on polarization build-up of unpolarized beams in storage rings and 5, 9, and 3 talks on low, medium, and high energy polarimeters, respectively. In this paper I will briefly describe a few highlights from these sessions, giving emphasis to topics which I think will play an important role in the future. copyright 1995 American Institute of Physics
Juettner Fernandes, Bonnie
2014-01-01
What really happened during the Big Bang? Why did matter form? Why do particles have mass? To answer these questions, scientists and engineers have worked together to build the largest and most powerful particle accelerator in the world: the Large Hadron Collider. Includes glossary, websites, and bibliography for further reading. Perfect for STEM connections. Aligns to the Common Core State Standards for Language Arts. Teachers' Notes available online.
International Nuclear Information System (INIS)
Krivoruchenko, M.I.
1985-01-01
In chiral bag model an expression is obtained for the quark wave functions with account of color and pion interaction of quarks. The quadrupole moments of nonstrange hadrons are calculated. Quadrupole moment of nucleon isobar is found to be Q(Δ)=-6.3x10 -28 esub(Δ)(cm)sup(2). Fredictions of the chiral bag model are in strong disagreement with the non-relativistic quark model
Electromagnetic polarizabilities of hadrons
International Nuclear Information System (INIS)
Friar, J.L.
1988-01-01
Electromagnetic polarizabilities of hadrons are reviewed, after a discussion of classical analogues. Differences between relativistic and non-relativistic approaches can lead to conflicts with conventional nuclear physics sum rules and calculational techniques. The nucleon polarizabilities are discussed in the context of the non-relativistic valence quark model, which provides a good qualitative description. The recently measured pion polarizabilities are discussed in the context of chiral symmetry and quark-loop models. 58 refs., 5 figs
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J.; Deshpande, Abhay L.; Gao, Haiyan; McKeown, Robert D.; Meyer, Curtis A.; Meziani, Zein-Eddine; Milner, Richard G.; Qiu, Jianwei; Richards, David G.; Roberts, Craig D.
2015-02-26
This White Paper presents the recommendations and scientific conclusions from the Town Meeting on QCD and Hadronic Physics that took place in the period 13-15 September 2014 at Temple University as part of the NSAC 2014 Long Range Planning process. The meeting was held in coordination with the Town Meeting on Phases of QCD and included a full day of joint plenary sessions of the two meetings. The goals of the meeting were to report and highlight progress in hadron physics in the seven years since the 2007 Long Range Plan (LRP07), and present a vision for the future by identifying the key questions and plausible paths to solutions which should define the next decade. The introductory summary details the recommendations and their supporting rationales, as determined at the Town Meeting on QCD and Hadron Physics, and the endorsements that were voted upon. The larger document is organized as follows. Section 2 highlights major progress since the 2007 LRP. It is followed, in Section 3, by a brief overview of the physics program planned for the immediate future. Finally, Section 4 provides an overview of the physics motivations and goals associated with the next QCD frontier: the Electron-Ion-Collider.
Keil, Eberhard
1998-01-01
Plans for future hadron colliders are presented, and accelerator physics and engineering aspects common to these machines are discussed. The Tevatron is presented first, starting with a summary of the achievements in Run IB which finished in 1995, followed by performance predictions for Run II which will start in 1999, and the TeV33 project, aiming for a peak luminosity $L ~ 1 (nbs)^-1$. The next machine is the Large Hadron Collider LHC at CERN, planned to come into operation in 2005. The last set of machines are Very Large Hadron Colliders which might be constructed after the LHC. Three variants are presented: Two machines with a beam energy of 50 TeV, and dipole fields of 1.8 and 12.6 T in the arcs, and a machine with 100 TeV and 12 T. The discussion of accelerator physics aspects includes the beam-beam effect, bunch spacing and parasitic collisions, and the crossing angle. The discussion of the engineering aspects covers synchrotron radiation and stored energy in the beams, the power in the debris of the p...
Hadronization, spin and lifetimes
International Nuclear Information System (INIS)
Grossman, Yuval; Nachshon, Itay
2008-01-01
Measurements of lifetimes can be done in two ways. For very short lived particles, the width can be measured. For long lived ones, the lifetime can be directly measured, for example, using a displaced vertex. Practically, the lifetime cannot be extracted for particles with intermediate lifetimes. We show that for such cases information about the lifetime can be extracted for heavy colored particles that can be produced with known polarization. For example, a t-like particle with intermediate lifetime hadronizes into a superposition of the lowest two hadronic states, T* and T (the equivalent of B* and B). Depolarization effects are governed by time scales that are much longer than the hadronization time scale, Λ QCD -1 . After a time of order 1/Δm, with Δm≡m(T*)-m(T), half of the initial polarization is lost. The polarization is totally lost after a time of order 1/Γ γ , with Γ γ = Γ(T* → Tγ). Thus, by comparing the initial and final polarization, we get information on the particle's lifetime.
Supersymmetry at hadron supercolliders
International Nuclear Information System (INIS)
Dzialo, D.L.
1989-01-01
At the next generation of hadron supercolliders, the proposed US Superconducting Supercollider (SSC) and the European Large Hadron Collider (LHC), protons will be collided at such high energy to allow the creation of new particles with masses greater those that have been previously created in the laboratory. One of the most important questions to be resolved at these accelerators is whether or not any supersymmetric extension of the Standard Model is manifest below the TeV scale. It is expected that the strongly-interacting supersymmetric particles, the gluinos and squarks, will be pair-produced in the most abundance there. Light gluinos primarily decay into quarks and the lightest supersymmetric particle, which is assumed to escape detection; this gives the classic supersymmetric signature of events with large missing momentum. It is known, however, that for gluinos of masses larger than just 100 GeV this process is no longer the preferred gluino decay channel. New signals must therefore be sought to either detect these particles, or to set meaningful lower mass limits. It is in this work that such new detection strategies for supersymmetry at hadron supercolliders are proposed. Gluino and squark production rates and decay channels are studied in a model-independent fashion over the entire theoretical mass range of interest. New experimental signatures are proposed and compared with sources of background over a wide region of the parameter space that characterizes different supersymmetric models
The role of hadron resonances in hot hadronic matter
Energy Technology Data Exchange (ETDEWEB)
Goity, Jose [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hampton Univ., Hampton, VA (United States)
2017-02-01
Hadron resonances can play a significant role in hot hadronic matter. Of particular interest for this workshop are the contributions of hyperon resonances. The question about how to quantify the effects of resonances is here addressed. In the framework of the hadron resonance gas, the chemically equilibrated case, relevant in the context of lattice QCD calculations, and the chemically frozen case relevant in heavy ion collisions are discussed.
Akaygun, Sevil
2016-01-01
Visualizing the chemical structure and dynamics of particles has been challenging for many students; therefore, various visualizations and tools have been used in chemistry education. For science educators, it has been important to understand how students visualize and represent particular phenomena--i.e., their mental models-- to design more…
Are Hadrons and Nuclei Open Systems ?
International Nuclear Information System (INIS)
Musulmanbekov, G.
1998-01-01
Fulltext We propose to consider the structure of hadrons in the frame of stochastic interpretation of quantum mechanics, or stochastic theory, which is based on classical mechanics in stochastic environment. This environment is associated with subquantal vacuum. Stochastic theory is a classical physics without the hypothesis that there are isolated systems in the universe. It has been shown by some authors that stochastic theory is justified by fractal space-time considerations. In our approach hadron is a set of embedded into stochastic vacuum (SV) valence quarks (VQ) ( quark-antiquark in mesons and three quarks in baryons ) oscillating near center of proper frame of the hadron VQ being placed into SV behaves itself as a dislocation (antidislocation) in solids or vortex ( antivortex ) in liquids. Effective interaction between VQs comes from specific polarization of SV around VQs leading to outside suppression on VQs. Polarization of SV around VQ characterizes the distribution of hardonic matter inside a hadron. Oscillation motion of VQs around the origin, going from their interaction with SV, is strongly correlated. VQs being in equilibrium with SV exchange energy at all times with it. Neighborhood of two or more nucleons changes SV polarization around their VQs in such a way that they tend to occupy the state with minimum energy arrange crystalline like structure. Therefore the behavior of hadrons and nuclei is typical for open systems exchanging energy with environment .In this approach the relation between constituent (nonrelativistic ) quarks and current ( relativistic) ones becomes clear and transparent, because it composes the features of both NRQM and bag models. It gives qualitative and in some cases quantitative description of experimental facts concerning nucleon and nuclear structure searched in scattering experiments. Some proposals and predictions for future experiments are given
Bisplinghoff, Raymond L; Pian, Theodore HH
2014-01-01
Profusely illustrated exposition of fundamentals of solid mechanics and principles of mechanics, statics, and simple statically indeterminate systems. Covers strain and stress in three-dimensional solids, elementary elasticity, energy principles in solid continuum, and more. 1965 edition.
Behavior of the hadron potential at large distances and properties of the hadron spin-flip amplitude
International Nuclear Information System (INIS)
Predazzi, E.; Selyugin, O.V.
2002-01-01
The impact of the form of the hadron potential at large distances on the behavior of the hadron spin-flip amplitude at small angles is examined. The t-dependence of the spin-flip amplitude of high-energy hadron elastic scattering is analyzed under different assumptions on the hadron interaction. It is shown that the long tail of the nonGaussian form of the hadron potential of the hadron interaction in the impact parameter representation leads to a large value of the slope of the spin-flip amplitude (without the kinematical factor √(vertical stroke t vertical stroke)) as compared with the slope of the spin-nonflip amplitude. This effect can explain the form of the differential cross-section and the analyzing power at small transfer momenta. The methods for the definition of the spin-dependent part of the hadron scattering amplitude are presented. A possibility to investigate the structure of the hadron spin-flip amplitude from the accurate measure of the differential cross-section and the spin correlation parameters is shown. (orig.)
Gavva, L. M.; Endogur, A. I.
2018-02-01
The mathematical model relations for stress-strain state and for buckling investigation of structurally-anisotropic panels made of composite materials are presented. The mathematical model of stiffening rib being torsioned under one-side contact with the skin is refined. One takes into account the influence of panel production technology: residual thermal stresses and reinforcing fibers preliminary tension. The resolved eight order equation and natural boundary conditions are obtained with variation Lagrange procedure. Exact analytical solutions for edge problems are considered. Computer program package is developed using operating MATLAB environment. The influence of the structure parameters on the level of stresses, displacements, of critical buckling forces for bending and for torsion modes has analyzed.
Static and high-frequency magnetic properties of stripe domain structure in a plate of finite sizes
International Nuclear Information System (INIS)
Mal'ginova, S.D.; Doroshenko, R.A.; Shul'ga, N.V.
2006-01-01
A model that enables to carry out self-consistent calculations of the main parameters of stripe domain structure (DS) and at the same time those of properties of domain walls (DW) of a multiple-axis finite (in all directions) ferromagnet depending on the sizes of a sample, material parameters and intensity of a magnetic field is offered. The calculations of the properties of DS (direction of magnetization in domains, widths, ferromagnetic resonance, etc.) are carried out on a computer for plates (1 1 0), rectangular shapes of a cubic ferromagnet with axes of light magnetization along trigonal directions in a magnetic field [-1 1 0]. It is shown, that in plates of different shapes there can be a structure with Neel DW alongside with DS with Bloch DW. Their features are noticeably exhibited, in particular, in different dependence of the number of domains, and also frequencies of a ferromagnetic resonance from a magnetic field
Meoni, Andrea; D'Alessandro, Antonella; Downey, Austin; García-Macías, Enrique; Rallini, Marco; Materazzi, A Luigi; Torre, Luigi; Laflamme, Simon; Castro-Triguero, Rafael; Ubertini, Filippo
2018-03-09
The availability of new self-sensing cement-based strain sensors allows the development of dense sensor networks for Structural Health Monitoring (SHM) of reinforced concrete structures. These sensors are fabricated by doping cement-matrix mterials with conductive fillers, such as Multi Walled Carbon Nanotubes (MWCNTs), and can be embedded into structural elements made of reinforced concrete prior to casting. The strain sensing principle is based on the multifunctional composites outputting a measurable change in their electrical properties when subjected to a deformation. Previous work by the authors was devoted to material fabrication, modeling and applications in SHM. In this paper, we investigate the behavior of several sensors fabricated with and without aggregates and with different MWCNT contents. The strain sensitivity of the sensors, in terms of fractional change in electrical resistivity for unit strain, as well as their linearity are investigated through experimental testing under both quasi-static and sine-sweep dynamic uni-axial compressive loadings. Moreover, the responses of the sensors when subjected to destructive compressive tests are evaluated. Overall, the presented results contribute to improving the scientific knowledge on the behavior of smart concrete sensors and to furthering their understanding for SHM applications.
Directory of Open Access Journals (Sweden)
Andrea Meoni
2018-03-01
Full Text Available The availability of new self-sensing cement-based strain sensors allows the development of dense sensor networks for Structural Health Monitoring (SHM of reinforced concrete structures. These sensors are fabricated by doping cement-matrix mterials with conductive fillers, such as Multi Walled Carbon Nanotubes (MWCNTs, and can be embedded into structural elements made of reinforced concrete prior to casting. The strain sensing principle is based on the multifunctional composites outputting a measurable change in their electrical properties when subjected to a deformation. Previous work by the authors was devoted to material fabrication, modeling and applications in SHM. In this paper, we investigate the behavior of several sensors fabricated with and without aggregates and with different MWCNT contents. The strain sensitivity of the sensors, in terms of fractional change in electrical resistivity for unit strain, as well as their linearity are investigated through experimental testing under both quasi-static and sine-sweep dynamic uni-axial compressive loadings. Moreover, the responses of the sensors when subjected to destructive compressive tests are evaluated. Overall, the presented results contribute to improving the scientific knowledge on the behavior of smart concrete sensors and to furthering their understanding for SHM applications.
Hadron collider physics at UCR
International Nuclear Information System (INIS)
Kernan, A.; Shen, B.C.
1997-01-01
This paper describes the research work in high energy physics by the group at the University of California, Riverside. Work has been divided between hadron collider physics and e + -e - collider physics, and theoretical work. The hadron effort has been heavily involved in the startup activities of the D-Zero detector, commissioning and ongoing redesign. The lepton collider work has included work on TPC/2γ at PEP and the OPAL detector at LEP, as well as efforts on hadron machines
Search for structure in sigma(e+e-→hadrons) between √s = 10.34 and 11.6 GeV
International Nuclear Information System (INIS)
Rice, E.; Boehringer, T.; Franzini, P.; Han, K.; Herb, S.W.; Mageras, G.; Peterson, D.; Yoh, J.K.; Lee-Franzini, J.; Giannini, G.; Schamberger, R.D. Jr.; Sivertz, M.; Spencer, L.J.; Tuts, P.M.; Imlay, R.; Levman, G.; Metcalf, W.; Sreedhar, V.; Blanar, G.; Dietl, H.; Eigen, G.; Lorenz, E.; Pauss, F.; Vogel, H.
1982-01-01
The CUSB detector at the Cornell electron storage ring has been used to measure R-sigma(e + e - →hadrons)/sigma(e + e - →μ + μ - ) in the c.m. energy regions between the UPSILON'' and the UPSILON''', and above the UPSILON''' up to √s = 11.6 GeV, with integrated luminosities of 5000 and 2100 nb -1 , respectively. No narrow resonances are observed, and limits on the leptonic widths are presented. The average value of R increases by 0.31 +- 0.06 across the flavor threshold
Correlations in back-to-back hadron production in SIDIS
Energy Technology Data Exchange (ETDEWEB)
Avakian, Harut [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Pisano, Silvia [National Inst. of Nuclear Physics (INFN), Frascati (Italy). National Lab. of Frascati (INFN-LNF)
2016-08-01
The Deep Inelastic Scattering (DIS) proved to be a great tool in testing of the theory of strong in- teractions. Semi-Inclusive DIS (SIDIS), with detection of an additional hadron allowed first stud- ies of 3D structure of the nucleon, moving the main focus from testing the QCD to understanding of strong interactions and quark gluon dynamics to address a number of puzzles accumulated in recent years. Detection of two hadrons in SIDIS, which is even more complicated, provides ac- cess to details of quark gluon interactions inaccessible in single-hadron SIDIS, providing a new avenue to study the complex nucleon structure. Large acceptance of the CLAS detector at Jef- ferson Lab, allowing detection of two hadrons, produced back-to-back (b2b) in the current and target fragmentation regions, provides a unique possibility to study the nucleon structure in target fragmentation region, and correlations of target and current fragmentation regions
Inelastic hadron reactions using a streamer chamber triggered by a single-arm spectrometer
2002-01-01
This experiment will investigate hard hadron-hadron collisions where a large fraction of the total energy is carried off at large angles with respect to the incident beam direction. The measurements will be done in the energy range of 200-400 GeV and with various hadrons ($\\pi^{\\pm}, K^{\\pm}, p, \\bar{p}$) incident on a liquid-hydrogen target. \\\\ \\\\The following questions will be investigated: \\\\ \\\\i) Is there a scaling law in hard hadron-hadron collisions which is similar to the scaling laws observed in lepton-hadron and $e^{+}e^{-}$ collisions? \\\\ ii) What do the multiparticle final states look like? Are there jets and if so do they reflect the parton structure of hadrons? Do the final states produced in deep inelastic hadron-hadron scattering look similar to those produced in deep inelastic lepton-hadron scattering? \\\\ iii) Are heavy objects and/or new quantum numbers produced in hard hadron-hadron collisions? \\\\ \\\\The apparatus comprises a vertex magnet (1 m gap, 2 m diameter, 15 kG) with a 30 cm long hyd...
Energy Technology Data Exchange (ETDEWEB)
Kundu, Ananya; Pradhan, Subrata, E-mail: pradhan@ipr.res.in; Ghate, Mahesh; Kanabar, Deven; Roy, Swati; Kumar, Nitish
2017-01-15
3D transient thermo-structural analyses and steady state magnetic field analyses of 1:1 prototyped JET Edge Localized Mode (ELM) coils have been carried out. Temperature distribution within the magnet winding as well as the temperature evolution have also been simulated as a function of pulsed transport currents in both large and small ELM coils as per the operational scenarios. The induced thermal stresses along with the shear stress components acting on the winding elements have also been analyzed. The deformations caused by thermal stresses have been calculated for the case, the conductor bundle and the insulation layers within the coils. In addition to thermo-structural analyses, steady state magnetic field analyses have also been carried out in the current carrying ELM coils. These values have been compared with the experimental values. The experimentally obtained values matches well with those obtained in simulations indicating that the prototyped ELM coils can operate successfully in JET operational scenarios. Additionally, the R & D and technologies developed in the context of JET ELM coils have also been validated with the magnet performances experimentally.
Light-Front Dynamics in Hadron Physics
International Nuclear Information System (INIS)
Ji, C.-R.; Bakker, B.L.G.; Choi, H.-M.
2013-01-01
Light-front dynamics(LFD) plays an important role in the analyses of relativistic few-body systems. As evidenced from the recent studies of generalized parton distributions (GPDs) in hadron physics, a natural framework for a detailed study of hadron structures is LFD due to its direct application in Minkowski space as well as its distinct feature of accounting for the vacuum fluctuations in quantum field theories. In the last few years, however, it has been emphasized that treacherous points such as LF singularities and zero-modes should be taken into account for successful LFD applications to hadron phenomenology. In this paper, we discuss a typical example of the contemporary relativistic hadron physics in which the fundamental issues should be taken into account for the successful application of LFD. In particular, we focus on the kinematic issue of GPDs in deeply virtual Compton scattering (DVCS). Although this fundamental issue has been glossed over in the literature, it must be taken care of for the correct analysis of DVCS data. (author)
Hadron Spectroscopy with COMPASS – Newest Results
Directory of Open Access Journals (Sweden)
Nerling Frank
2012-12-01
Full Text Available The COMPASS experiment at the CERN SPS investigates the structure and spectrum of hadrons by scattering high energetic hadrons and polarised muons off various fixed targets. During the years 2002–2007, COMPASS focused on nucleon spin physics using 160 GeV/c polarised µ+ beams on polarised deuteron and proton targets, including measurements of the gluon contribution to the nucleon spin using longitudinal target polarisation as well as studies of transverse spin effects in the nucleon on a transversely polarised target. One major goal of the physics programme using hadron beams is the search for new states, in particular the search for JPC exotic states and glue-balls. COMPASS measures not only charged but also neutral final-state particles, allowing for investigation of new objects in different reactions and decay channels. In addition COMPASS can measure low-energy QCD constants like, e.g. the electromagnetic polarisability of the pion. Apart from a few days pilot run data taken in 2004 with a 190 GeV/c π− beam on a Pb target, showing a significant spin-exotic JPC = 1−+ resonance at around 1660 MeV/c2, COMPASS collected high statistics with negative and positive 190 GeV/c hadron beams on a proton (H2 and nuclear (Ni, Pb targets in 2008 and 2009. We give a selected overview of the newest results and discuss the status of various ongoing analyses.
Summary: Hadron dynamics sessions
International Nuclear Information System (INIS)
Carroll, A.S.; Londergan, J.T.
1993-01-01
Four sessions on Hadron Dynamics were organized at this Workshop. The first topic, QCD Exclusive Reactions and Color Transparency, featured talks by Ralston, Heppelman and Strikman; the second, QCD and Inclusive Reactions had talks by Garvey, Speth and Kisslinger. The third dynamics session, Medium Modification of Elementary Interactions had contributions from Kopeliovich, Alves and Gyulassy; the fourth session Pre-QCD Dynamics and Scattering, had talks by Harris, Myhrer and Brown. An additional joint Spectroscopy/Dynamics session featured talks by Zumbro, Johnson and McClelland. These contributions are reviewed briefly in this summary. Two additional joint sessions between Dynamics and η physics are reviewed by the organizers of the Eta sessions. In such a brief review there is no way the authors can adequately summarize the details of the physics presented here. As a result, they concentrate only on brief impressionistic sketches of the physics topics discussed and their interrelations. They include no bibliography in this summary, but simply refer to the talks given in more detail in the Workshop proceedings. They focus on topics which were common to several presentations in these sessions. First, nuclear and particle descriptions of phenomena are now clearly converging, in both a qualitative and quantitative sense; they show several examples of this convergence. Second, an important issue in hadron dynamics is the extent to which elementary interactions are modified in nuclei at high energies and/or densities, and they illustrate some of these medium effects. Finally, they focus on those dynamical issues where hadron facilities can make an important, or even a unique, contribution to the knowledge of particle and nuclear physics
Energy Technology Data Exchange (ETDEWEB)
Anon.
1979-04-15
Ever since the discovery of charmed mesons in electron-positron annihilations at SLAC and DESY, a considerable effort has gone into looking for them in other types of reactions. Both neutrino interactions and photoproduction have provided further data on the production and decay of D mesons, but little has emerged concerning purely hadronic studies.some results from a CERN/Collège de France/Heidelberg/Karlsruhe collaboration using the Split Field Magnet at the CERN Intersecting Storage Rings (ISR) now show definite signs of D meson production in proton-proton collisions.
International Nuclear Information System (INIS)
Faccini, R.
2010-01-01
In the past few years the field of hadron spectroscopy has seen renewed interest due to the publication, initially mostly from B-Factories, of evidences of states that do not match regular spectroscopy, but are rather candidates for bound states with additional quarks or gluons (four quarks for tetraquarks and molecules and two quarks and gluons for hybrids). A huge effort in understanding the nature of this new states and in building a new spectroscopy is ongoing. This paper reviews the experimental and theoretical state of the art on heavy quarkonium exotic spectroscopy, with particular attention on the steps towards a global picture.
International Nuclear Information System (INIS)
Cohen-Tannoudji, G.
1989-01-01
This series of lectures is devoted to review ot he connections between QCD and string theories. One reviews the phenomenological models leading to string pictures in non perturbative QCD and the string effects, related to soft gluon coherence, which arise in perturbative QCD. One tries to build a string theory which goes to QCD at the zero slope limit. A specific model, based on superstring theories is shown to agree with QCD four point amplitudes at the Born approximation and with one loop corrections. One shows how this approach can provide a theoretical framework to account for the phenomenological property of parton-hadron duality.(author)
Directory of Open Access Journals (Sweden)
Wada Masayuki
2012-11-01
Full Text Available The results of resonance particle productions (ρ0, ω, K*, ϕ, Σ*, and Λ* measured by the STAR collaboration at RHIC from various colliding systems and energies are presented. Measured mass, width, 〈pT〉, and yield of those resonances are reviewed. No significant mass shifts or width broadening beyond the experiment uncertainties are observed. New measurements of ϕ and ω from leptonic decay channels are presented. The yields from leptonic decay channels are compared with the measurements from hadronic decay channels and the two results are consistent with each other.
Hadronic matrix elements in the QCD on the lattice
International Nuclear Information System (INIS)
Altmeyer, R.
1995-01-01
The work describes a lattice simulation of full QCD with dynamical Kogut-Susskind fermions. We evaluated different hadronic matrix elements which are related to the static and low-energy behaviour of hadrons. The analysis was performed on a 16 3 x 24 lattice with a coupling constant of β = 5.35 and a quark mass of m = 0.010. The calculations are based on a set of 85 configurations created by using a Hybrid-Monte-Carlo algorithm. First we evaluated the mass and energy spectrum of the low-lying hadrons using local operators as well as non-local operators. As the complete spectrum of the different pion and ρ meson lattice representations has been calculated we were able to check the restoration of continuum flavor symmetry. Moreover, the determination of energies E of hadron states with non-vanishing momentum vector q made it possible to investigate the lattice dispersion function E( vector q). Another part of the presented work is the determination of mesonic decay constants which parameterise the weak decay of mesons. They are related to hadronic matrix elements of the respective quark currents and through the calculation of these matrix elements we were able to determine the decay constants f π and f ρ . Before doing so, we calculated non-perturbatively renormalization constants for the currents under consideration. The next part is the determination of hadronic coupling constants. These parameterise in an effective low-energy model the interactions of different hadrons. They are related to hadronic matrix elements whose lattice calculation can be dpme bu evaluating 3-point correlation functions. Thus we evaluted the hadronic coupling constants g ρππ and g NNπ . Finally, an investigation of the pion-nucleon σterm was done. The σterm is defined through a hadronic matrix element of a quark-antiquark operator and can thus be evaluated on the lattice via the calculation of a 3-point correlation function. As we determined the connected and the disconnected
Energy Technology Data Exchange (ETDEWEB)
Sokolov, N. S., E-mail: nsokolov@fl.ioffe.ru; Fedorov, V. V.; Korovin, A. M.; Suturin, S. M.; Baranov, D. A.; Gastev, S. V.; Krichevtsov, B. B.; Bursian, V. E.; Lutsev, L. V. [Ioffe Physical-Technical Institute of Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); Maksimova, K. Yu.; Grunin, A. I. [Immanuel Kant Baltic Federal University, Kaliningrad 236041 (Russian Federation); Tabuchi, M. [Synchrotron Radiation Research Center, Nagoya University, Nagoya 464-8603 (Japan)
2016-01-14
Pulsed laser deposition has been used to grow thin (10–84 nm) epitaxial layers of Yttrium Iron Garnet Y{sub 3}Fe{sub 5}O{sub 12} (YIG) on (111)–oriented Gadolinium Gallium Garnet substrates at different growth conditions. Atomic force microscopy showed flat surface morphology both on micrometer and nanometer scales. X-ray diffraction measurements revealed that the films are coherent with the substrate in the interface plane. The interplane distance in the [111] direction was found to be by 1.2% larger than expected for YIG stoichiometric pseudomorphic film indicating presence of rhombohedral distortion in this direction. Polar Kerr effect and ferromagnetic resonance measurements showed existence of additional magnetic anisotropy, which adds to the demagnetizing field to keep magnetization vector in the film plane. The origin of the magnetic anisotropy is related to the strain in YIG films observed by XRD. Magneto-optical Kerr effect measurements revealed important role of magnetization rotation during magnetization reversal. An unusual fine structure of microwave magnetic resonance spectra has been observed in the film grown at reduced (0.5 mTorr) oxygen pressure. Surface spin wave propagation has been demonstrated in the in-plane magnetized films.
International Nuclear Information System (INIS)
Sokolov, N. S.; Fedorov, V. V.; Korovin, A. M.; Suturin, S. M.; Baranov, D. A.; Gastev, S. V.; Krichevtsov, B. B.; Bursian, V. E.; Lutsev, L. V.; Maksimova, K. Yu.; Grunin, A. I.; Tabuchi, M.
2016-01-01
Pulsed laser deposition has been used to grow thin (10–84 nm) epitaxial layers of Yttrium Iron Garnet Y 3 Fe 5 O 12 (YIG) on (111)–oriented Gadolinium Gallium Garnet substrates at different growth conditions. Atomic force microscopy showed flat surface morphology both on micrometer and nanometer scales. X-ray diffraction measurements revealed that the films are coherent with the substrate in the interface plane. The interplane distance in the [111] direction was found to be by 1.2% larger than expected for YIG stoichiometric pseudomorphic film indicating presence of rhombohedral distortion in this direction. Polar Kerr effect and ferromagnetic resonance measurements showed existence of additional magnetic anisotropy, which adds to the demagnetizing field to keep magnetization vector in the film plane. The origin of the magnetic anisotropy is related to the strain in YIG films observed by XRD. Magneto-optical Kerr effect measurements revealed important role of magnetization rotation during magnetization reversal. An unusual fine structure of microwave magnetic resonance spectra has been observed in the film grown at reduced (0.5 mTorr) oxygen pressure. Surface spin wave propagation has been demonstrated in the in-plane magnetized films
Andreaus, Ugo; Spagnuolo, Mario; Lekszycki, Tomasz; Eugster, Simon R.
2018-04-01
We present a finite element discrete model for pantographic lattices, based on a continuous Euler-Bernoulli beam for modeling the fibers composing the pantographic sheet. This model takes into account large displacements, rotations and deformations; the Euler-Bernoulli beam is described by using nonlinear interpolation functions, a Green-Lagrange strain for elongation and a curvature depending on elongation. On the basis of the introduced discrete model of a pantographic lattice, we perform some numerical simulations. We then compare the obtained results to an experimental BIAS extension test on a pantograph printed with polyamide PA2200. The pantographic structures involved in the numerical as well as in the experimental investigations are not proper fabrics: They are composed by just a few fibers for theoretically allowing the use of the Euler-Bernoulli beam theory in the description of the fibers. We compare the experiments to numerical simulations in which we allow the fibers to elastically slide one with respect to the other in correspondence of the interconnecting pivot. We present as result a very good agreement between the numerical simulation, based on the introduced model, and the experimental measures.
PREFACE: Focus section on Hadronic Physics
Roberts, Craig; Swanson, Eric
2007-07-01
Hadronic physics is the study of strongly interacting matter and its underlying theory, Quantum Chromodynamics (QCD). The field had its beginnings after World War Two, when hadrons were discovered in ever increasing numbers. Today, it encompasses topics like the quark-gluon structure of hadrons at varying scales, the quark-gluon plasma and hadronic matter at extreme temperature and density; it also underpins nuclear physics and has significant impact on particle physics, astrophysics, and cosmology. Among the goals of hadronic physics are to determine the parameters of QCD, understand the origin and characteristics of confinement, understand the dynamics and consequences of dynamical chiral symmetry breaking, explore the role of quarks and gluons in nuclei and in matter under extreme conditions and understand the quark and gluon structure of hadrons. In general, the process is one of discerning the relevant degrees of freedom and relating these to the fundamental fields of QCD. The emphasis is on understanding QCD, rather than testing it. The papers gathered in this special focus section of Journal of Physics G: Nuclear and Particle Physics attempt to cover this broad range of subjects. Alkofer and Greensite examine the issue of quark and gluon confinement with the focus on models of the QCD vacuum, lattice gauge theory investigations, and the relationship to the AdS/CFT correspondence postulate. Arrington et al. review nucleon form factors and their role in determining quark orbital momentum, the strangeness content of the nucleon, meson cloud effects, and the transition from nonperturbative to perturbative QCD dynamics. The physics associated with hadronic matter at high temperature and density and at low Bjorken-x at the Relativistic Heavy Ion Collider (RHIC), the SPS at CERN, and at the future LHC is summarized by d'Enterria. The article of Lee and Smith examines experiment and theory associated with electromagnetic meson production from nucleons and
Statics of historic masonry constructions
Como, Mario
2017-01-01
Masonry constructions are the great majority of the buildings in Europe’s historic centres and the most important monuments of its architectural heritage. Given the age of these constructions, the demand for safety assessments and restoration projects is pressing and constant; still within the broad studies in the subject it is not yet recognised, in particular within the seismic area, a unitary approach to deal with Masonry structures. This successful book contributes to clarify the issues with a rigorous approach offering a comprehensive new Statics of Masonry Constructions. This third edition has been driven by some recent developments of the research in the field, and it gives the fundamentals of Statics with an original and rigorous mathematical formulation, further in-depth inquired in this new version. With many refinements and improvements, the book investigates the static behaviour of many historic monuments, such as the Gothic Cathedrals, the Mycenaean Tholoi, the Pantheon, the Colosseum, the dome...
Excitations of single-beauty hadrons
Burch, Tommy; Hagen, Christian; Lang, Christian B.; Limmer, Markus; Schäfer, Andreas
2009-01-01
In this work we study the predominantly orbital and radial excitations of hadrons containing a single heavy quark. We present meson and baryon mass splittings and ratios of meson decay constants (e.g., fBs/fB and fBs'/fBs) resulting from quenched and dynamical two-flavor configurations. Light quarks are simulated using the chirally improved lattice Dirac operator at valence masses as light as Mπ≈350MeV. The heavy quark is approximated by a static propagator, appropriate for the b quark on our lattices (1/ã1-2GeV). We also include some preliminary calculations of the O(1/mQ) kinetic corrections to the states, showing, in the process, a viable way of applying the variational method to three-point functions involving excited states. We compare our results with recent experimental findings.
Excitations of single-beauty hadrons
International Nuclear Information System (INIS)
Burch, Tommy; Hagen, Christian; Lang, Christian B.; Limmer, Markus; Schaefer, Andreas
2009-01-01
In this work we study the predominantly orbital and radial excitations of hadrons containing a single heavy quark. We present meson and baryon mass splittings and ratios of meson decay constants (e.g., f B s /f B and f B s ' /f B s ) resulting from quenched and dynamical two-flavor configurations. Light quarks are simulated using the chirally improved lattice Dirac operator at valence masses as light as M π ≅350 MeV. The heavy quark is approximated by a static propagator, appropriate for the b quark on our lattices (1/a∼1-2 GeV). We also include some preliminary calculations of the O(1/m Q ) kinetic corrections to the states, showing, in the process, a viable way of applying the variational method to three-point functions involving excited states. We compare our results with recent experimental findings.
High energy hadron-nucleus collision
International Nuclear Information System (INIS)
Takagi, Fujio
1983-02-01
This is a lecture note concerning high energy hadron-nucleus collision. The lecture gives the inelastic total cross section and the Glanber approximate multiple scattering formula at first. The mechanism of nuclear spallation is described in a cylindrical image. The multiplicity, the one particle distribution and the time-space structure of particle production are discussed. Various models are presented. The attenuation of forward particles and the structure of hadrons are discussed for each model. The atomic number (A) dependence of the production of large transverse momentum particles and jet, and the A dependence of charged multiplicity are presented. The backward production of particles and many body correlation are discussed. Lepton pair production and the initial interaction of constituents, collective interaction, multi quark state and phase transition are described. (Kato, T.)
Hadron Correlations and Parton Recombination
Energy Technology Data Exchange (ETDEWEB)
Fries, R.J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)]. E-mail: rjfries@comp.tamu.edu
2007-02-15
Parton recombination has been found to be an extremely useful model to understand hadron production at the Relativistic Heavy Ion Collider. It is particularly important to explore its connections with hard processes. This article reviews some of the aspects of the quark recombination model and places particular emphasis on hadron correlations.
Quarkonium production in hadronic collisions
International Nuclear Information System (INIS)
Gavai, R.; Schuler, G.A.; Sridhar, K.
1995-01-01
We summarize the theoretical description of charmonium and bottonium production in hadronic collisions and compare it to the available data from hadron-nucleon interactions. With the parameters of the theory established by these data, we obtain predictions for quarkonium production at RHIC and LHC energies
Hadron induced leptons and photons
International Nuclear Information System (INIS)
Cronin, J.W.
1977-01-01
A review of direct production of leptons and photons in hadron-hadron collisions is presented. Production of lepton pairs with large mass is well accounted for by the Drell-Yan process. The origin of direct single leptons is principally due to the production of lepton pairs. A dominant source of lepton pairs is at low effective mass, m [de
Current Status of Exotic Hadrons
International Nuclear Information System (INIS)
Saeed, M.A.; Ahmed, Maqsood; Fazal-e-Aleem
2005-01-01
Physics of exotic hadrons is in the limelight these days. The models for these baryons are discussed as well as their production and decay processes and methods of their identification. The results of recent experiments in this field are presented, in which some unusual states are observed. These states are candidates for exotic hadrons
Hadrons in dense matter. Proceedings
International Nuclear Information System (INIS)
Buballa, M.; Noerenberg, W.; Schaefer, B.J.; Wambach, J.
2000-03-01
The following topics were dealt with: Elementary hadronic reactions, Delta dynamics in nuclei, in-medium s-wave ππ-correlations, strangeness in hot and dense matter, medium modifications of vector mesons and dilepton production, medium modifications of charmonium, thermal properties of hot and dense hadronic matter, nuclear matter, spectral functions and QCD sum rules
NLO Quarkonium Production in Hadronic Collisions
Mangano, Michelangelo L.
1996-01-01
We present some preliminary results on the next-to-leading order calculation in QCD of quarkonium production cross sections in hadronic collisions. We will show that the NLO total cross sections for $P$-wave states produced at high energy are not reliable, due to the appearance of very large and negative contributions. We also discuss some issues related to the structure of final states in colour-octet production and to high-p_T fragmentation.
Jet shapes in hadron and electron colliders
International Nuclear Information System (INIS)
Wainer, N.
1993-05-01
High energy jets are observed both in hadronic machines like the Tevatron and electron machines like LEP. These jets have an extended structure in phase space which can be measured. This distribution is usually called the jet shape. There is an intrinsic relation between jet variables, like energy and direction, the jet algorithm used, and the jet shape. Jet shape differences can be used to separate quark and gluon jets
The high resolution spaghetti hadron calorimeter
International Nuclear Information System (INIS)
Jenni, P.; Sonderegger, P.; Paar, H.P.; Wigmans, R.
1987-01-01
It is proposed to build a prototype for a hadron calorimeter with scintillating plastic fibres as active material. The absorber material is lead. Provided that these components are used in the appropriate volume ratio, excellent performance may be expected, e.g. an energy resolution of 30%/√E for jet detection. The proposed design offers additional advantages compared to the classical sandwich calorimeter structures in terms of granularity, hermiticity, uniformity, compactness, readout, radiation resistivity, stability and calibration. 22 refs.; 7 figs
Preface to the Special Issue: Chiral Symmetry in Hadrons and Nuclei
International Nuclear Information System (INIS)
Geng, Lisheng; Meng, Jie; Zhao, Qiang; Zou, Bingsong
2014-01-01
The recent past years have seen a remarkable progress towards a unified description of nonperturbative strong interaction phenomena based on the fundamental theory of the strong interaction, quantum chromodynamics, and effective field theories. The papers collected in this special issue focus on the recent progress in hadron and nuclear physics related to the chiral symmetry. They are written based on presentations at the Seventh International Symposium on Chiral Symmetry in Hadron and Nuclei which took place at Beihang University, Beijing, 27-30 October 2013. The sub-topics discussed in these papers include chiral and heavy-quark spin symmetry; chiral dynamics of few-body hadron systems; chiral symmetry and hadrons in a nuclear medium; chiral dynamics in nucleon-nucleon interaction and atomic nuclei; chiral symmetry in rotating nuclei; hadron structure and interactions; exotic hadrons, heavy flavor hadrons and nuclei; mesonic atoms and nuclei
Dutta, S; Kumar, A; Skoczen, B; Soni, H C
2004-01-01
The Short Straight Section (SSS) of the Large Hadron Collider (LHC) may undergo relative displacements between cold-mass and cryostat for the following three reasons: - Fabrication tolerance of interconnection bellows - Global smoothing after pre-alignment - Ground motion in a sector of the LHC tunnel The forces responsible for such displacements stem from finite stiffness of interconnect bellows & metal hoses of the internal piping of the jumper connection and from relatively flexible 'glass fibre reinforced epoxy' (GFRE) composite supports of the cold mass. In addition, the vacuum jacket of the jumper connection and the large sleeves attached to both ends of SSS produce elastic deformations of the cryostat vessel. A unified finite element model consisting of cryostat, large sleeves, vacuum jacket of jumper, interconnection bellows, internal piping of jumper, composite cold supports and alignment jacks has been prepared. The knowledge of the position of the cold mass with respect to its cryostat under va...
Hadron muoproduction at the COMPASS experiment
International Nuclear Information System (INIS)
Rajotte, Jean-Francois
2010-01-01
The COMPASS Collaboration has two main fields of interest: to improve our knowledge of the nucleon spin structure and to study hadrons through spectroscopy. These goals require a multipurpose universal spectrometer such as the COmmon Muon and Proton Apparatus for Structure and Spectroscopy, COMPASS. In its first years of data taking (2002-2007), the nucleon spin structure was studied with a polarized muon beam scattering off a polarized target. These studies resumed in 2010 and will continue until at least 2011. The years 2008 and 2009 were dedicated to hadron spectroscopy using hadron beams. In the case of the nucleon structure studies, it is crucial to detect with high precision the incoming beam muon (160 GeV), the scattered muon and the produced hadrons. The large amount of high quality data accumulated provides access to the unpolarized and polarized parton distributions of the nucleon and the hadronization process. Subtle differences (asymmetries) between polarized cross sections have been predicted for hadron production from polarized muon-nucleon interaction for COMPASS. It is based on these differences that the polarized parton distributions can be measured. In this context, it is important to first compare predictions with the gross features of the measured unpolarized semi-inclusive differential cross sections or the closely related differential multiplicities. In order to determine cross sections, the data has to be corrected for the acceptance of the spectrometer. In this thesis, a multidimensional acceptance correction method, based on Monte Carlo simulation, is developed and applied to the data measured in 2004. The method is first used to determine the inclusive muon-nucleon cross section which is compared with a global fit to world data. This serves as a test of the acceptance correction method and to verify if the results from previous experiments can be reproduced. Then, unpolarized differential multiplicities as a function of transverse momentum
Hadron muoproduction at the COMPASS experiment
Energy Technology Data Exchange (ETDEWEB)
Rajotte, Jean-Francois
2010-09-30
The COMPASS Collaboration has two main fields of interest: to improve our knowledge of the nucleon spin structure and to study hadrons through spectroscopy. These goals require a multipurpose universal spectrometer such as the COmmon Muon and Proton Apparatus for Structure and Spectroscopy, COMPASS. In its first years of data taking (2002-2007), the nucleon spin structure was studied with a polarized muon beam scattering off a polarized target. These studies resumed in 2010 and will continue until at least 2011. The years 2008 and 2009 were dedicated to hadron spectroscopy using hadron beams. In the case of the nucleon structure studies, it is crucial to detect with high precision the incoming beam muon (160 GeV), the scattered muon and the produced hadrons. The large amount of high quality data accumulated provides access to the unpolarized and polarized parton distributions of the nucleon and the hadronization process. Subtle differences (asymmetries) between polarized cross sections have been predicted for hadron production from polarized muon-nucleon interaction for COMPASS. It is based on these differences that the polarized parton distributions can be measured. In this context, it is important to first compare predictions with the gross features of the measured unpolarized semi-inclusive differential cross sections or the closely related differential multiplicities. In order to determine cross sections, the data has to be corrected for the acceptance of the spectrometer. In this thesis, a multidimensional acceptance correction method, based on Monte Carlo simulation, is developed and applied to the data measured in 2004. The method is first used to determine the inclusive muon-nucleon cross section which is compared with a global fit to world data. This serves as a test of the acceptance correction method and to verify if the results from previous experiments can be reproduced. Then, unpolarized differential multiplicities as a function of transverse momentum
Static electromagnetic frequency changers
Rozhanskii, L L
1963-01-01
Static Electromagnetic Frequency Changers is about the theory, design, construction, and applications of static electromagnetic frequency changers, devices that used for multiplication or division of alternating current frequency. It is originally published in the Russian language. This book is organized into five chapters. The first three chapters introduce the readers to the principles of operation, the construction, and the potential applications of static electromagnetic frequency changers and to the principles of their design. The two concluding chapters use some hitherto unpublished work
Thimm, Jens C
2017-12-01
The Computerized Adaptive Test of Personality Disorder-Static Form (CAT-PD-SF) is a self-report inventory developed to assess pathological personality traits. The current study explored the reliability and higher order factor structure of the Norwegian version of the CAT-PD-SF and the relationships between the CAT-PD traits and domains of personality functioning in an undergraduate student sample ( N = 375). In addition to the CAT-PD-SF, the short form of the Severity Indices of Personality Problems and the Brief Symptom Inventory were administered. The results showed that the Norwegian CAT-PD-SF has good score reliability. Factor analysis of the CAT-PD-SF scales indicated five superordinate factors that correspond to the trait domains of the alternative DSM-5 model for personality disorders. The CAT-PD traits were highly predictive of impaired personality functioning after controlling for psychological distress. It is concluded that the CAT-PD-SF is a promising tool for the assessment of personality disorder traits.
Nguyen-Thanh, Nhon; Li, Weidong; Zhou, Kun
2018-03-01
This paper develops a coupling approach which integrates the meshfree method and isogeometric analysis (IGA) for static and free-vibration analyses of cracks in thin-shell structures. In this approach, the domain surrounding the cracks is represented by the meshfree method while the rest domain is meshed by IGA. The present approach is capable of preserving geometry exactness and high continuity of IGA. The local refinement is achieved by adding the nodes along the background cells in the meshfree domain. Moreover, the equivalent domain integral technique for three-dimensional problems is derived from the additional Kirchhoff-Love theory to compute the J-integral for the thin-shell model. The proposed approach is able to address the problems involving through-the-thickness cracks without using additional rotational degrees of freedom, which facilitates the enrichment strategy for crack tips. The crack tip enrichment effects and the stress distribution and displacements around the crack tips are investigated. Free vibrations of cracks in thin shells are also analyzed. Numerical examples are presented to demonstrate the accuracy and computational efficiency of the coupling approach.
HIGH ENERGY HADRON POLARIMETRY
International Nuclear Information System (INIS)
BUNCE, G.
2007-01-01
Proton polarimetry at RHIC uses the interference of electromagnetic (EM) and hadronic scattering amplitudes. The EM spin-flip amplitude for protons is responsible for the proton's anomalous magnetic moment, and is large. This then generates a significant analyzing power for small angle elastic scattering. RHIC polarimetry has reached a 5% uncertainty on the beam polarization, and seem capable of reducing this uncertainty further. Polarized neutron beams ax also interesting for RHIC and for a polarized electron-polarized proton/ion collider in the fume. In this case, deuterons, for example, have a very small anomalous magnetic moment, making the approach used for protons impractical. Although it might be possible to use quasielastic scattering from the protons in the deuteron to monitor the polarization. 3-He beams can provide polarized neutrons, and do have a large anomalous magnetic moment, making a similar approach to proton polarimetry possible
CMS hadronic forward calorimeter
International Nuclear Information System (INIS)
Merlo, J.P.
1998-01-01
Tests of quartz fiber prototypes, based on the detection of Cherenkov light from showering particles, demonstrate a detector possessing all of the desirable characteristics for a forward calorimeter. A prototype for the CMS experiment consists of 0.3 mm diameter fibers embedded in a copper matrix. The response to high energy (10-375 GeV) electrons, pions, protons and muons, the light yield, energy and position resolutions, and signal uniformity and linearity, are discussed. The signal generation mechanism gives this type of detector unique properties, especially for the detection of hadronic showers: Narrow, shallow shower profiles, hermeticity and extremely fast signals. The implications for measurements in the high-rate, high-radiation LHC environment are discussed. (orig.)
International Nuclear Information System (INIS)
Eyraud, L; Furget, C.; Goy, J.; Kox, S.; Merchez, F.; Pastor, A.; Real, J.S.; Russew, T.; Tieulent, R.; Voutier, E.
1997-01-01
Over these two years, our group has been worked in hadronic physics at Saturn and CEBAF using the polarimeter POLDER. Tensor polarization observables have been measured in the reaction H(p bar, d bar)π + between 580 and 1300 MeV proton energy. The group has also been leader in an experiment, performed in 1997 at CEBAF. By measuring the t 20 polarization of the recoil deuteron produced in the elastic electron-deuteron scattering at large Q 2 , the separation of the charge and quadrupole form-factors of the deuteron will be performed for Q=4.1-6.8 fm -1 . Finally, we were involved in the construction and test of the neutron polarimeter HARP and in the definition of the physics program of the ELFE project. (authors)
Hadron mass corrections in semi-inclusive deep inelastic scattering
International Nuclear Information System (INIS)
Accardi, A.; Hobbs, T.; Melnitchouk, W.
2009-01-01
We derive mass corrections for semi-inclusive deep inelastic scattering of leptons from nucleons using a collinear factorization framework which incorporates the initial state mass of the target nucleon and the final state mass of the produced hadron h. The hadron mass correction is made by introducing a generalized, finite-Q 2 scaling variable ζ h for the hadron fragmentation function, which approaches the usual energy fraction z h = E h /ν in the Bjorken limit. We systematically examine the kinematic dependencies of the mass corrections to semi-inclusive cross sections, and find that these are even larger than for inclusive structure functions. The hadron mass corrections compete with the experimental uncertainties at kinematics typical of current facilities, Q 2 2 and intermediate x B > 0.3, and will be important to efforts at extracting parton distributions from semi-inclusive processes at intermediate energies.
Hadronic physics with multi-GeV electrons
International Nuclear Information System (INIS)
Mathiot, J.F.
1993-04-01
The contacts between nuclear and particle physics have become closer and closer these last ten years, in particular with the development of what is now called hadronic physics. It is shown why the first low lying hadrons, nucleons and pions, are now identified as the relevant physical degrees of freedom in nuclei. As a direct consequence of this description it is shown how the nucleon and pion properties can be modified in the nuclear medium. The new directions that have emerged the last few years to study the microscopic structure of hadrons are indicated, in particular it is shown how the nucleus can be used to unravel the quark dynamics inside hadrons. (author). 25 refs., 18 figs., 1 tab
The COMPASS Setup for Physics with Hadron Beams
Abbon, Ph.; Akhunzyanov, R.; Alexandrov, Yu.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Burtin, E.; Capozza, L.; Ciliberti, P.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Colantoni, M.; Cotte, D.; Crespo, M.L.; Curiel, Q.; Dafni, T.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Desforge, D.; Dinkelbach, A.M.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Durand, D.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Gatignon, L.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Geyer, R.; Giganon, A.; Gnesi, I.; Gobbo, B.; Goertz, S.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Gregori, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F.H.; Herrmann, F.; Hinterberger, F.; Hoppner, Ch.; Horikawa, N.; d'Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Jorg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.; Kramer, M.; Kroumchtein, Z.V.; Kuchinski, N.; Kuhn, R.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G.K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Menon, G.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Moinester, M.A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nunes, Ana Sofia; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pesaro, G.; Pesaro, V.; Peshekhonov, D.V.; Pires, C.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Reymond, J-M.; Rocco, E.; Rossiyskaya, N.S.; Rousse, J.Y.; Ryabchikov, D.I.; Rychter, A.; Samartsev, A.; Samoylenko, V.D.; Sandacz, A.; Sarkar, S.; Savin, I.A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schluter, T.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Schott, M.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Wolbeek, J. ter; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tskhay, V.; Uhl, S.; Uman, I.; Virius, M.; Wang, L.; Weisrock, T.; Weitzel, Q.; Wilfert, M.; Windmolders, R.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.
2015-01-01
The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This article describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup.
Quark-Hadron Duality in Electron Scattering
Energy Technology Data Exchange (ETDEWEB)
Wally Melnitchouk; Rolf Ent; Cynthia Keppel
2004-08-01
The duality between partonic and hadronic descriptions of physical phenomena is one of the most remarkable features of strong interaction physics. A classic example of this is in electron-nucleon scattering, in which low-energy cross sections, when averaged over appropriate energy intervals, are found to exhibit the scaling behavior expected from perturbative QCD. We present a comprehensive review of data on structure functions in the resonance region, from which the global and local aspects of duality are quantified, including its flavor, spin and nuclear medium dependence. To interpret the experimental findings, we discuss various theoretical approaches which have been developed to understand the microscopic origins of quark-hadron duality in QCD. Examples from other reactions are used to place duality in a broader context, and future experimental and theoretical challenges are identified.
Perspectives in hadron and quark dynamics
International Nuclear Information System (INIS)
Amsler, C.; Bressani, T.; Close, F.E.; De Sanctis, E.; Frois, B.; Kunne, F.; Laget, J.M.; von Harrach, D.; Metag, V.; Mulders, P.J.; Riska, D.O.
1997-01-01
In the past two decades, quantum chromodynamics (QCD) has emerged as the theory for the strong force with quarks and gluons as the building blocks of nuclear matter at large densities and high temperatures. One of the most exciting challenges for nuclear physics is the study of the non-perturbative regime of QCD. It is this regime which is relevant for understanding how the elementary fields of QCD - quarks and gluons - build up particles such as protons and neutrons. A basic theoretical difficulty is the non-existence of asymptotic, isolated, colored objects. This is a feature of the richness of the vacuum structure of QCD. Understanding the different QCD phases and the transitions among them is the challenge of the modern study of strong interactions. At low energy, chiral symmetry can be used to build aneffective theory of hadron interactions. At higher energies, the parton model uses non-perturbative quark and gluon distributions to describe hadronic scattering processes. (orig)
Large transverse momentum hadronic processes
International Nuclear Information System (INIS)
Darriulat, P.
1977-01-01
The possible relations between deep inelastic leptoproduction and large transverse momentum (psub(t)) processes in hadronic collisions are usually considered in the framework of the quark-parton picture. Experiments observing the structure of the final state in proton-proton collisions producing at least one large transverse momentum particle have led to the following conclusions: a large fraction of produced particles are uneffected by the large psub(t) process. The other products are correlated to the large psub(t) particle. Depending upon the sign of scalar product they can be separated into two groups of ''towards-movers'' and ''away-movers''. The experimental evidence are reviewed favouring such a picture and the properties are discussed of each of three groups (underlying normal event, towards-movers and away-movers). Some phenomenological interpretations are presented. The exact nature of away- and towards-movers must be further investigated. Their apparent jet structure has to be confirmed. Angular correlations between leading away and towards movers are very informative. Quantum number flow, both within the set of away and towards-movers, and between it and the underlying normal event, are predicted to behave very differently in different models
The common elements of atomic and hadronic physics
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J., E-mail: sjbth@slac.stanford.edu [Stanford University, SLAC National Accelerator Laboratory (United States)
2015-08-15
Atomic physics and hadronic physics are both governed by the Yang Mills gauge theory Lagrangian; in fact, Abelian quantum electrodynamics can be regarded as the zero-color limit of quantum chromodynamics. I review a number of areas where the techniques of atomic physics can provide important insight into hadronic eigenstates in QCD. For example, the Dirac-Coulomb equation, which predicts the spectroscopy and structure of hydrogenic atoms, has an analog in hadron physics in the form of frame-independent light-front relativistic equations of motion consistent with light-front holography which give a remarkable first approximation to the spectroscopy, dynamics, and structure of light hadrons. The production of antihydrogen in flight can provide important insight into the dynamics of hadron production in QCD at the amplitude level. The renormalization scale for the running coupling is unambiguously set in QED; an analogous procedure sets the renormalization scales in QCD, leading to scheme-independent scale-fixed predictions. Conversely, many techniques which have been developed for hadron physics, such as scaling laws, evolution equations, the quark-interchange process and light-front quantization have important applicants for atomic physics and photon science, especially in the relativistic domain.
The Common Elements of Atomic and Hadronic Physics
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J. [SLAC National Accelerator Lab., Menlo Park, CA (United States)
2015-02-26
Atomic physics and hadronic physics are both governed by the Yang Mills gauge theory Lagrangian; in fact, Abelian quantum electrodynamics can be regarded as the zero-color limit of quantum chromodynamics. I review a number of areas where the techniques of atomic physics can provide important insight into hadronic eigenstates in QCD. For example, the Dirac-Coulomb equation, which predicts the spectroscopy and structure of hydrogenic atoms, has an analog in hadron physics in the form of frame-independent light-front relativistic equations of motion consistent with light-front holography which give a remarkable first approximation to the spectroscopy, dynamics, and structure of light hadrons. The production of antihydrogen in flight can provide important insight into the dynamics of hadron production in QCD at the amplitude level. The renormalization scale for the running coupling is unambiguously set in QED; an analogous procedure sets the renormalization scales in QCD, leading to scheme-independent scale-fixed predictions. Conversely, many techniques which have been developed for hadron physics, such as scaling laws, evolution equations, the quark-interchange process and light-front quantization have important applicants for atomic physics and photon science, especially in the relativistic domain.
Hadron collider physics 2005. Proceedings
International Nuclear Information System (INIS)
Campanelli, M.; Clark, A.; Wu, X.
2006-01-01
The Hadron Collider Physics Symposia (HCP) are a new series of conferences that follow the merger of the Hadron Collider Conferences with the LHC Symposia series, with the goal of maximizing the shared experience of the Tevatron and LHC communities. This book gathers the proceedings of the first symposium, HCP2005, and reviews the state of the art in the key physics directions of experimental hadron collider research: - QCD physics - precision electroweak physics - c-, b-, and t-quark physics - physics beyond the Standard Model - heavy ion physics The present volume will serve as a reference for everyone working in the field of accelerator-based high-energy physics. (orig.)
Heavy quarks in hadronic collisions
International Nuclear Information System (INIS)
Brodsky, S.J.; Peterson, C.
1982-03-01
It is suggested that the presence of c anti c-pairs on the 1 to 2% level in the hadron Fock state decomposition (intrinsic charm) gives a natural description of the ISR data for charm hadron production. The theoretical foundations of the intrinsic charm hypothesis together with its consequences for lepton- and hadron-induced reactions are discussed in some detail. There is no contradiction with the EMC data on F 2 /sup c/ provided the appropriate threshold dependence is taken into account
Physics at Future Hadron Colliders
Baur, U.; Parsons, J.; Albrow, M.; Denisov, D.; Han, T.; Kotwal, A.; Olness, F.; Qian, J.; Belyaev, S.; Bosman, M.; Brooijmans, G.; Gaines, I.; Godfrey, S.; Hansen, J.B.; Hauser, J.; Heintz, U.; Hinchliffe, I.; Kao, C.; Landsberg, G.; Maltoni, F.; Oleari, C.; Pagliarone, C.; Paige, F.; Plehn, T.; Rainwater, D.; Reina, L.; Rizzo, T.; Su, S.; Tait, T.; Wackeroth, D.; Vataga, E.; Zeppenfeld, D.
2001-01-01
We discuss the physics opportunities and detector challenges at future hadron colliders. As guidelines for energies and luminosities we use the proposed luminosity and/or energy upgrade of the LHC (SLHC), and the Fermilab design of a Very Large Hadron Collider (VLHC). We illustrate the physics capabilities of future hadron colliders for a variety of new physics scenarios (supersymmetry, strong electroweak symmetry breaking, new gauge bosons, compositeness and extra dimensions). We also investigate the prospects of doing precision Higgs physics studies at such a machine, and list selected Standard Model physics rates.
Fundamentals in hadronic atom theory
Deloff, A
2003-01-01
Hadronic atoms provide a unique laboratory for studying hadronic interactions essentially at threshold. This text is the first book-form exposition of hadronic atom theory with emphasis on recent developments, both theoretical and experimental. Since the underlying Hamiltonian is a non-self-adjoined operator, the theory goes beyond traditional quantum mechanics and this book covers topics that are often glossed over in standard texts on nuclear physics. The material contained here is intended for the advanced student and researcher in nuclear, atomic or elementary-particle physics. A good know
Hadron collider physics at UCR
Energy Technology Data Exchange (ETDEWEB)
Kernan, A.; Shen, B.C.
1997-07-01
This paper describes the research work in high energy physics by the group at the University of California, Riverside. Work has been divided between hadron collider physics and e{sup +}-e{sup {minus}} collider physics, and theoretical work. The hadron effort has been heavily involved in the startup activities of the D-Zero detector, commissioning and ongoing redesign. The lepton collider work has included work on TPC/2{gamma} at PEP and the OPAL detector at LEP, as well as efforts on hadron machines.
Hadronic wavefunctions in light-cone quantization
International Nuclear Information System (INIS)
Hyer, T.
1994-05-01
The analysis of light-cone wavefunctions seems the most promising theoretical approach to a detailed understanding of the structure of relativistic bound states, particularly hadrons. However, there are numerous complications in this approach. Most importantly, the light-cone approach sacrifices manifest rotational invariance in exchange for the elimination of negative-energy states. The requirement of rotational invariance of the full theory places important constraints on proposed light-cone wavefunctions, whether they are modelled or extracted from some numerical procedure. A formulation of the consequences of the hidden rotational symmetry has been sought for some time; it is presented in Chapter 2. In lattice gauge theory or heavy-quark effective theory, much of the focus is on the extraction of numerical values of operators which are related to the hadronic wavefunction. These operators are to some extent interdependent, with relations induced by fundamental constraints on the underlying wavefunction. The consequences of the requirement of unitarity are explored in Chapter 3, and are found to have startling phenomenological relevance. To test model light-cone wavefunctions, experimental predictions must be made. The reliability of perturbative QCD as a tool for making such predictions has been questioned. In Chapter 4, the author presents a computation of the rates for nucleon-antinucleon annihilation, improving the reliability of the perturbative computation by taking into account the Sudakov suppression of exclusive processes at large transverse impact parameter. In Chapter 5, he develops the analysis of semiexclusive production. This work focuses on processes in which a single isolated meson is produced perturbatively and recoils against a wide hadronizing system. At energies above about 10 GeV, semiexclusive processes are shown to be the most sensitive experimental probes of hadronic structure
Factorization for short distance hadron-hadron scattering
International Nuclear Information System (INIS)
Collins, J.C.; Illinois Inst. of Tech., Chicago; Soper, D.E.; Sterman, G.
1985-01-01
We show that factorization holds at leading twist in the Drell-Yang cross section dsigma/dQ 2 dy and related inclusive hadron-hadron cross sections. We review the heuristic arguments for factorization, as well as the difficulties which must be overcome in a proof. We go on to give detailed arguments for the all order cancellation of soft gluons, and to show how this leads to factorization. (orig.)
Simulation of soft hadron hadron collisions at ultrarelativistic energies
International Nuclear Information System (INIS)
Werner, K.
1987-01-01
An event generator to simulate ultrarelativistic hadron hadron collisions is proposed. It is based on the following main assumptions: the process can be divided into two independent steps, string formation and string fragmentation; strings are formed as a consequence of color exchange between a quark of the projectile and a quark of the target; the fragmentation of strings is the same as in e + e - annihilation or in lepton nucleon scattering. 11 refs., 4 figs
Hadronic production of high p$_{T}$ leptons and hadrons
2002-01-01
This experiment measures the production of direct real photons with large transverse momentum in pion-nucleon collisions at the SPS (H8 beam) using the NA3 spectrometer with an upgraded e-$\\gamma$ calorimeter. The experiment proceeds in steps of increasing complexity: \\item a) measurement of the direct $\\gamma$ cross-section in $\\pi^{\\pm}$C $\\rightarrow \\gamma +$ X and search for the annihilation process $q\\bar{q} \\rightarrow \\gamma$g by measuring the charge asymmetry at 200 GeV/c; \\item b) determination of the gluon structure function of the pion and the nucleon; \\item c) use of the $\\pi^{-}-\\pi^{+}$ difference on carbon, if found experimentally, to extract the gluon fragmentation from the $\\gamma$ hadron correlations. \\end{enumerate}\\\\ \\\\ For comparison, the quark fragmentation functions can, in principle, be extracted from processes where the Compton scattering qg $\\rightarrow$ q$\\gamma$ dominates and compared with data from D.I.S. as a test of the method. \\\\ \\\\ The existing standard NA3 spectrometer is we...
International Nuclear Information System (INIS)
Ashman, J.; Combley, F.; Salmon, D.; Whalley, M.; Wheeler, S.; Baum, G.; Caputo, M.C.; Hughes, V.W.; Oppenheim, R.F.; Papavassiliou, V.; Piegaia, R.; Schueler, K.P.; Bee, C.P.; Brown, S.C.; Court, G.; Francis, D.; Gabathuler, E.; Gamet, R.; Hayman, P.; Holt, J.R.; Jones, T.; Matthews, M.; Wimpenny, S.J.; Cheung, H.W.K.; Gibson, V.; Gillies, J.; Loken, J.; Renton, P.; Taylor, G.N.; Williams, W.S.C.; Womersley, J.; Coignet, G.; Favier, J.; Nagy, E.; Toth, J.; Urban, L.; Drees, J.; Edwards, A.W.; Hamacher, K.; Korzen, B.; Kruener, U.; Lauterjung, D.; Moenig, K.; Pavel, N.; Peschel, H.; Pietrzyk, U.; Schneider, A.; Wahlen, H.; Dycew, N.; Sloan, T.; Ernst, T.; Landgraf, U.; Schlagboehmer, A.; Schroeder, T.; Stier, H.E.; Stock, J.; Wallucks, W.; Ferrero, M.I.; Peroni, C.; Stajano, A.; Grafstroem, P.; Kullander, S.; Lettenstroem, F.; Lindqvist, T.; Lanske, D.; Schultze, K.; Urban, L.; Ziemons, K.; Windmolders, R.
1991-01-01
Final data measured with the EMC forward spectrometer are presented on the production of forward charged hardons in μp and μd scattering at incident beam energies between 100 and 280 GeV. The large statistics of 373 000 events allows a study of the semi-inclusive hadron production as a function of z, p T 2 and T 2 > in small Q 2 , x Bj and W bins. Charge multiplicity ratios and differences as a function of z and x Bj are given for p, d and n-targets. From the differences of charge multiplicities the ratio of the valence quark distributions of the proton d v (x)/u v (x) is determined for the first time in charged lepton scattering. The Gronau et al. sum rule is tested, the measured sum being 0.31±0.06 stat.±0.05 syst., compared with the theoretical expectation of 2/7≅0.286. The measured sum corresponds to an absolute value of the ratio of the d and u quark charge of 0.44±0.10 stat.±0.08 syst. (orig.)
Large Hadron Collider nears completion
2008-01-01
Installation of the final component of the Large Hadron Collider particle accelerator is under way along the Franco-Swiss border near Geneva, Switzerland. When completed this summer, the LHC will be the world's largest and most complex scientific instrument.
The CMS Outer Hadron Calorimeter
Acharya, Bannaje Sripathi; Banerjee, Sunanda; Banerjee, Sudeshna; Bawa, Harinder Singh; Beri, Suman Bala; Bhandari, Virender; Bhatnagar, Vipin; Chendvankar, Sanjay; Deshpande, Pandurang Vishnu; Dugad, Shashikant; Ganguli, Som N; Guchait, Monoranjan; Gurtu, Atul; Kalmani, Suresh Devendrappa; Kaur, Manjit; Kohli, Jatinder Mohan; Krishnaswamy, Marthi Ramaswamy; Kumar, Arun; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mondal, Naba Kumar; Nagaraj, P; Narasimham, Vemuri Syamala; Patil, Mandakini Ravindra; Reddy, L V; Satyanarayana, B; Sharma, Seema; Singh, B; Singh, Jas Bir; Sudhakar, Katta; Tonwar, Suresh C; Verma, Piyush
2006-01-01
The CMS hadron calorimeter is a sampling calorimeter with brass absorber and plastic scintillator tiles with wavelength shifting fibres for carrying the light to the readout device. The barrel hadron calorimeter is complemented with a outer calorimeter to ensure high energy shower containment in CMS and thus working as a tail catcher. Fabrication, testing and calibrations of the outer hadron calorimeter are carried out keeping in mind its importance in the energy measurement of jets in view of linearity and resolution. It will provide a net improvement in missing $\\et$ measurements at LHC energies. The outer hadron calorimeter has a very good signal to background ratio even for a minimum ionising particle and can hence be used in coincidence with the Resistive Plate Chambers of the CMS detector for the muon trigger.
Quark confinement and hadronic interactions
International Nuclear Information System (INIS)
Lenz, F.
1985-01-01
With the possibility for 'exact' calculations within the framework of a fundamental theory, QCD, the role of models in strong interaction physics is changing radically. The relevance of detailed numerical model studies is diminishing with the development of those exact, numerical approaches to QCD. On the other hand, the insight gained from such purely numerical studies is necessarily limited and must be complemented by the more qualitative but also more intuitive insight gained from model studies. In particular, the subject of hadron-hadron interactions requires model studies to relate the wide variety of strong interaction physics to the fundamental properties of strong interaction physics. The author reports on such model studies of the hadron-hadron interaction
Hadron energy resolution at ICAL
International Nuclear Information System (INIS)
Devi, Moon Moon; Ghosh, Anushree; Kaur, Daljeet; Mohan, Lakshmi S.
2013-01-01
We have performed a simulation study for determining the hadron energy resolution of INO-ICAL detector within a GEANT4 based simulation framework. We do this by propagating single pions from a fixed or a randomised vertex, as also with the NUANCE (neutrino event generator) generated events in which hadrons are produced in the energy range (0.5 ≤ E ≤ 15 GeV). Hadron interactions produce a shower of hits inside the detector. The energy of hadrons can therefore be reconstructed only by taking these hits into account. Hit distribution for each energy and angle bin has been obtained and analyzed. In order to find the suitable fit for such hit distributions a comparative study has been performed by applying different fit functions and results will be shown
Fixed target hadron production measurements
Panman, J
2009-01-01
The knowledge of light hadron production cross-sections in proton-nucleus interactions is an important prerequisite to the analysis of a wide variety of experiments. One of the important limiting factors for the precision of accelerator based and atmospheric neutrino oscillation experiments is the uncertainty in the composition and spectrum of the neutrino flux. Cosmic-ray experiments detecting extensive air-showers can greatly improve their ability to interpret the data when precise hadron production spectra are available over a large range of energies. Dedicated hadron production experiments have been taking data recently and are now publishing their results. Other experiments have just started their data-taking and plan to supply measurements which can significantly extend the kinematic range in which data will be available. Early measurements at the LHC can extend this range to much higher energies than available up to now. Recent results will be shown and compared with hadronic production models. An outl...
Topological objects in hadron physics
International Nuclear Information System (INIS)
Rho, M.
1988-01-01
The notion of topological objects in hadronic physics is discussed, with emphasis on the role of the Wess-Zumino term and induced transmutation of quantum numbers in chiral bag models. Some applications to nuclear systems are given
Ericson fluctuations in hadron scattering
International Nuclear Information System (INIS)
Frautschi, S.
1975-01-01
It is shown that there are resonances with high mass and long lives, at the very least, longer than the 10 -23 second transit time across a hadron. The theoretical and then the experimental approaches to this problem are described
B factory with hadron colliders
International Nuclear Information System (INIS)
Lockyer, N.S.
1990-01-01
The opportunities to study B physics in a hadron collider are discussed. Emphasis is placed on the technological developments necessary for these experiments. The R and D program of the Bottom Collider Detector group is reviewed. (author)
Zawaira, Alexander; Coulson, Lauren; Gallotta, Marco; Karimanzira, Owen; Blackburn, Jonathan
2011-02-01
Differential tunnel-opening patterns were established in static structures of mammalian CYP450 isoforms and subsequently applied to identify tunnel-intersecting residues. The identified tunnel-intersecting residues permitted the subsequent construction of gating models via the identification of intra-protein interactions. We define 28 two-state gating models and 37 singlet gating-residue models. Our results reveal the preponderance of aromatic gating residues in CYP3A4 and CYP2A6, whereas we find a preponderance of polar/charged residues in CYP2C5. In CYP2C8 there is balanced presence of polar/charged and hydrophobic aliphatic residues in gating models, whilst in CYP2C9 there is balanced presence of all residue-types. These patterns suggest fast evolutionary dynamics for gating residues and we find that the average rate of evolution of gating residues in CYP2C5, CYP2C8, CYP2C9 and CYP2A6 is significantly faster than the average rate of evolution of the entire sequence. Our study identifies 67% of calculable gating models identified in the literature by molecular dynamics approaches and 92% of residues appearing in literature models appear in our models. However, only 6% of the models identified in this work had been previously-described in the literature. This suggests that our study has defined the most comprehensive list yet of tunnel-gating models in mammalian CYP450 and in doing so have created a benchmark for molecular dynamics approaches to the ligand-tunnelling problem in CYP450. Copyright © 2010 Elsevier Inc. All rights reserved.
Japan Hadron Facility (JHF) project
International Nuclear Information System (INIS)
Nagamiya, S.
1999-01-01
The Japan Hadron Facility (JHF) is the next accelerator project proposed at KEK to promote exciting sciences by utilising high-intensity proton beams. The project is characterised by three unique features: hadronic beams of the world's highest intensity; a variety of beams from one accelerator complex; frontier sciences to cover a broad research area including nuclear physics, particle physics, material sciences and life sciences by utilising a common accelerator complex. (author)
Anisotropic superfluidity of hadronic matter
International Nuclear Information System (INIS)
Chela Flores, J.
1977-10-01
From a model of strong interactions with important general features (f-g model) and from recent experiments of Rudnick and co-workers on thin films of helium II, hadronic matter is considered as a new manifestation of anisotropic superfluidity. In order to test the validity of the suggestion, some qualitative features of multiparticle production of hadrons are considered, and found to have a natural explanation. A prediction is made following a recent experiment on π + p collisions
The ATLAS hadronic tau trigger
International Nuclear Information System (INIS)
Shamim, Mansoora
2012-01-01
The extensive tau physics programs of the ATLAS experiment relies heavily on trigger to select hadronic decays of tau lepton. Such a trigger is implemented in ATLAS to efficiently collect signal events, while keeping the rate of multi-jet background within the allowed bandwidth. This contribution summarizes the performance of the ATLAS hadronic tau trigger system during 2011 data taking period and improvements implemented for the 2012 data collection.
International Nuclear Information System (INIS)
Davier, M.
1999-12-01
Hadronic decays of the τ lepton provide a clean source to study hadron dynamics in an energy regime dominated by resonances, with the interesting information captured in the spectral functions. Recent results on exclusive channels are reviewed. Inclusive spectral functions are the basis for QCD analyses, delivering an accurate determination of the strong coupling constant and quantitative information on nonperturbative contributions. Strange decays yield a determination of the strange quark mass. (author)
Energy Technology Data Exchange (ETDEWEB)
Davier, M
1999-12-01
Hadronic decays of the {tau} lepton provide a clean source to study hadron dynamics in an energy regime dominated by resonances, with the interesting information captured in the spectral functions. Recent results on exclusive channels are reviewed. Inclusive spectral functions are the basis for QCD analyses, delivering an accurate determination of the strong coupling constant and quantitative information on nonperturbative contributions. Strange decays yield a determination of the strange quark mass. (author)
QCD SPIN PHYSICS IN HADRONIC INTERACTIONS.
Energy Technology Data Exchange (ETDEWEB)
VOGELSANG,W.
2007-06-19
We discuss spin phenomena in high-energy hadronic scattering, with a particular emphasis on the spin physics program now underway at the first polarized proton-proton collider, RHIC. Experiments at RHIC unravel the spin structure of the nucleon in new ways. Prime goals are to determine the contribution of gluon spins to the proton spin, to elucidate the flavor structure of quark and antiquark polarizations in the nucleon, and to help clarify the origin of transverse-spin phenomena in QCD. These lectures describe some aspects of this program and of the associated physics.
Higher-twist correlations in polarized hadrons
International Nuclear Information System (INIS)
Tangerman, R.D.
1996-01-01
In this thesis we studied the response of polarized hadrons to several high-energy probes, working in the framework of the field theoretic model. Emphasis is laid upon higher-twist effects such as quark transverse momentum. The inclusive DIS process is very well suited to study QCD. From general principles we were able to derive four positivity constraints on the structure functions without invoking the helicity formalism. The on-shell quark model is used to illustrate these constraints. Subseqeuently, we concentrated on the higher-twist structure function g 2 (x,Q 2 ). (orig./HSI)
A. Skuja
Since the beginning of 2007, HCAL has made significant progress in the installation and commissioning of both hardware and software. A large fraction of the physical Hadron Calorimeter modules have been installed in UX5. In fact, the only missing pieces are HE- and part of HO. The HB+/- were installed in the cryostat in March. HB scintillator layer-17 was installed above ground before the HB were lowered. The HB- scintillator layer-0 was installed immediately after completion of EB- installation. HF/HCAL Commissioning The commissioning and checkout of the HCAL readout electronics is also proceeding at a rapid pace in Bldg. 904 and USC55. All sixteen crates of HCAL VME readout electronics have been commissioned and certified for service. Fifteen are currently operating in the S2 level of USC55. The last crate is being used for firmware development in the Electronics Integration Facility in 904. All installed crates are interfaced to their VME computers and receive synchronous control from the fully-equipp...
High resolution hadron calorimetry
International Nuclear Information System (INIS)
Wigmans, R.
1987-01-01
The components that contribute to the signal of a hadron calorimeter and the factors that affect its performance are discussed, concentrating on two aspects; energy resolution and signal linearity. Both are decisively dependent on the relative response to the electromagnetic and the non-electromagnetic shower components, the e/h signal ratio, which should be equal to 1.0 for optimal performance. The factors that determine the value of this ratio are examined. The calorimeter performance is crucially determined by its response to the abundantly present soft neutrons in the shower. The presence of a considerable fraction of hydrogen atoms in the active medium is essential for achieving the best possible results. Firstly, this allows one to tune e/h to the desired value by choosing the appropriate sampling fraction. And secondly, the efficient neutron detection via recoil protons in the readout medium itself reduces considerably the effect of fluctuations in binding energy losses at the nuclear level, which dominate the intrinsic energy resolution. Signal equalization, or compensation (e/h = 1.0) does not seem to be a property unique to 238 U, but can also be achieved with lead and probably even iron absorbers. 21 refs.; 19 figs
Late effects from hadron therapy
Energy Technology Data Exchange (ETDEWEB)
Blakely, Eleanor A.; Chang, Polly Y.
2004-06-01
Successful cancer patient survival and local tumor control from hadron radiotherapy warrant a discussion of potential secondary late effects from the radiation. The study of late-appearing clinical effects from particle beams of protons, carbon, or heavier ions is a relatively new field with few data. However, new clinical information is available from pioneer hadron radiotherapy programs in the USA, Japan, Germany and Switzerland. This paper will review available data on late tissue effects from particle radiation exposures, and discuss its importance to the future of hadron therapy. Potential late radiation effects are associated with irradiated normal tissue volumes at risk that in many cases can be reduced with hadron therapy. However, normal tissues present within hadron treatment volumes can demonstrate enhanced responses compared to conventional modes of therapy. Late endpoints of concern include induction of secondary cancers, cataract, fibrosis, neurodegeneration, vascular damage, and immunological, endocrine and hereditary effects. Low-dose tissue effects at tumor margins need further study, and there is need for more acute molecular studies underlying late effects of hadron therapy.
Hadron electric polarizability from lattice QCD
Alexandru, Andrei
2017-09-01
Electromagnetic polarizabilities are important parameters for hadron structure, describing the response of the charge and current distributions inside the hadron to an external electromagnetic field. For most hadrons these quantities are poorly constrained experimentally since they can only be measured indirectly. Lattice QCD can be used to compute these quantities directly in terms of quark and gluons degrees of freedom, using the background field method. We present results for the neutron electric polarizability for two different quark masses, light enough to connect to chiral perturbation theory. These are currently the lightest quark masses used in polarizability studies. For each pion mass we compute the polarizability at four different volumes and perform an infinite volume extrapolation. We also discuss the effect of turning on the coupling between the background field and the sea quarks. A.A. is supported in part by the National Science Foundation CAREER Grant PHY-1151648 and by U.S. DOE Grant No. DE-FG02-95ER40907.
Thermal relaxation of charm in hadronic matter
Energy Technology Data Exchange (ETDEWEB)
He Min, E-mail: mhe@comp.tamu.edu [Cyclotron Institute and Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Fries, Rainer J. [Cyclotron Institute and Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); RIKEN/BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973 (United States); Rapp, Ralf [Cyclotron Institute and Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)
2011-07-18
The thermal relaxation rate of open-charm (D) mesons in hot and dense hadronic matter is calculated using empirical elastic scattering amplitudes. D-meson interactions with thermal pions are approximated by D{sup *} resonances, while scattering off other hadrons (K, {eta}, {rho}, {omega}, K{sup *}, N, {Delta}) is evaluated using vacuum scattering amplitudes as available in the literature based on effective Lagrangians and constrained by realistic spectroscopy. The thermal relaxation time of D-mesons in a hot {pi} gas is found to be around 25-50 fm/c for temperatures T=150-180 MeV, which reduces to 10-25 fm/c in a hadron-resonance gas. The latter values, argued to be conservative estimates, imply significant modifications of D-meson spectra in heavy-ion collisions. Close to the critical temperature (T{sub c}), the spatial diffusion coefficient (D{sub s}) is surprisingly similar to recent calculations for charm quarks in the Quark-Gluon Plasma using non-perturbative T-matrix interactions. This suggests a possibly continuous minimum structure of D{sub s} around T{sub c}.
Rectifier cabinet static breaker
International Nuclear Information System (INIS)
Costantino, R.A. Jr; Gliebe, R.J.
1992-01-01
A rectifier cabinet static breaker replaces a blocking diode pair with an SCR and the installation of a power transistor in parallel with the latch contactor to commutate the SCR to the off state. The SCR serves as a static breaker with fast turnoff capability providing an alternative way of achieving reactor scram in addition to performing the function of the replaced blocking diodes. The control circuitry for the rectifier cabinet static breaker includes on-line test capability and an LED indicator light to denote successful test completion. Current limit circuitry provides high-speed protection in the event of overload. 7 figs
Rectifier cabinet static breaker
Costantino, Jr, Roger A.; Gliebe, Ronald J.
1992-09-01
A rectifier cabinet static breaker replaces a blocking diode pair with an SCR and the installation of a power transistor in parallel with the latch contactor to commutate the SCR to the off state. The SCR serves as a static breaker with fast turnoff capability providing an alternative way of achieving reactor scram in addition to performing the function of the replaced blocking diodes. The control circuitry for the rectifier cabinet static breaker includes on-line test capability and an LED indicator light to denote successful test completion. Current limit circuitry provides high-speed protection in the event of overload.
PREFACE: Focus section on Hadronic Physics Focus section on Hadronic Physics
Roberts, Craig; Swanson, Eric
2007-07-01
Hadronic physics is the study of strongly interacting matter and its underlying theory, Quantum Chromodynamics (QCD). The field had its beginnings after World War Two, when hadrons were discovered in ever increasing numbers. Today, it encompasses topics like the quark-gluon structure of hadrons at varying scales, the quark-gluon plasma and hadronic matter at extreme temperature and density; it also underpins nuclear physics and has significant impact on particle physics, astrophysics, and cosmology. Among the goals of hadronic physics are to determine the parameters of QCD, understand the origin and characteristics of confinement, understand the dynamics and consequences of dynamical chiral symmetry breaking, explore the role of quarks and gluons in nuclei and in matter under extreme conditions and understand the quark and gluon structure of hadrons. In general, the process is one of discerning the relevant degrees of freedom and relating these to the fundamental fields of QCD. The emphasis is on understanding QCD, rather than testing it. The papers gathered in this special focus section of Journal of Physics G: Nuclear and Particle Physics attempt to cover this broad range of subjects. Alkofer and Greensite examine the issue of quark and gluon confinement with the focus on models of the QCD vacuum, lattice gauge theory investigations, and the relationship to the AdS/CFT correspondence postulate. Arrington et al. review nucleon form factors and their role in determining quark orbital momentum, the strangeness content of the nucleon, meson cloud effects, and the transition from nonperturbative to perturbative QCD dynamics. The physics associated with hadronic matter at high temperature and density and at low Bjorken-x at the Relativistic Heavy Ion Collider (RHIC), the SPS at CERN, and at the future LHC is summarized by d'Enterria. The article of Lee and Smith examines experiment and theory associated with electromagnetic meson production from nucleons and
International Nuclear Information System (INIS)
Leander, G.A.
1985-01-01
Certain nuclei can be described as having intrinsic shapes with parity breaking static moments. The rationale for this description is discussed, spectroscopic models are outlined and their consequences are compared with experiment. (orig.)
Statistical hadronization and hadronic micro-canonical ensemble II
International Nuclear Information System (INIS)
Becattini, F.; Ferroni, L.
2004-01-01
We present a Monte Carlo calculation of the micro-canonical ensemble of the ideal hadron-resonance gas including all known states up to a mass of about 1.8 GeV and full quantum statistics. The micro-canonical average multiplicities of the various hadron species are found to converge to the canonical ones for moderately low values of the total energy, around 8 GeV, thus bearing out previous analyses of hadronic multiplicities in the canonical ensemble. The main numerical computing method is an importance sampling Monte Carlo algorithm using the product of Poisson distributions to generate multi-hadronic channels. It is shown that the use of this multi-Poisson distribution allows for an efficient and fast computation of averages, which can be further improved in the limit of very large clusters. We have also studied the fitness of a previously proposed computing method, based on the Metropolis Monte Carlo algorithm, for event generation in the statistical hadronization model. We find that the use of the multi-Poisson distribution as proposal matrix dramatically improves the computation performance. However, due to the correlation of subsequent samples, this method proves to be generally less robust and effective than the importance sampling method. (orig.)
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
Time reversal odd fragmentation functions in semi-inclusive deep inelastic lepton-hadron scattering
Energy Technology Data Exchange (ETDEWEB)
Mulders, P.J. [National Inst. for Nuclear Physics and High Energy Physics, Amsterdam (Netherlands); Levelt, J. [Univ. of Erlangen-Nuernberg (Germany)
1994-04-01
In semi-inclusive scattering of polarized leptons from unpolarized hadrons, one can measure a time reversal odd structure function. It shows up as a sin({phi}) asymmetry of the produced hadrons. This asymmetry can be expressed as the product of a twist-three {open_quotes}hadron {r_arrow} quark{close_quotes} profile function and a time reversal odd twist-two {open_quotes}quark {r_arrow} hadron{close_quotes} fragmentation function. This fragmentation function can only be measured for nonzero transverse momenta of the produced hadron. Its appearance is a consequence of final state interactions between the produced hadron and the rest of the final state.
Hadronic and nuclear interactions in QCD
International Nuclear Information System (INIS)
1982-01-01
Despite the evidence that QCD - or something close to it - gives a correct description of the structure of hadrons and their interactions, it seems paradoxical that the theory has thus far had very little impact in nuclear physics. One reason for this is that the application of QCD to distances larger than 1 fm involves coherent, non-perturbative dynamics which is beyond present calculational techniques. For example, in QCD the nuclear force can evidently be ascribed to quark interchange and gluon exchange processes. These, however, are as complicated to analyze from a fundamental point of view as is the analogous covalent bond in molecular physics. Since a detailed description of quark-quark interactions and the structure of hadronic wavefunctions is not yet well-understood in QCD, it is evident that a quantitative first-principle description of the nuclear force will require a great deal of theoretical effort. Another reason for the limited impact of QCD in nuclear physics has been the conventional assumption that nuclear interactions can for the most part be analyzed in terms of an effective meson-nucleon field theory or potential model in isolation from the details of short distance quark and gluon structure of hadrons. These lectures, argue that this view is untenable: in fact, there is no correspondence principle which yields traditional nuclear physics as a rigorous large-distance or non-relativistic limit of QCD dynamics. On the other hand, the distinctions between standard nuclear physics dynamics and QCD at nuclear dimensions are extremely interesting and illuminating for both particle and nuclear physics
Observing the Forces Involved in Static Friction under Static Situations
Kaplan, Daniel
2013-01-01
Static friction is an important concept in introductory physics. Later in the year students apply their understanding of static friction under more complex conditions of static equilibrium. Traditional lab demonstrations in this case involve exceeding of the maximum level of static friction, resulting in the "onset of motion." (Contains…
Lepton-hadron scattering past and future
CERN. Geneva. Audiovisual Unit
1985-01-01
Lepton-hadron scattering experiments have played a key role in the development and verification of the Standard Model. The lectures will summarize the main ideas and experimental results concerning the substructure of the nucleon, the structure of the weak currents and the production of new particles. In a second step it will be discussed how experiments at e-p colliders like HERA can lead beyond the Standard Model by studying the substructure of quarks and leptons, the existence of new kinds of interaction and/or new particles.
Present and future of hadron spectroscopy at Jefferson Lab
Battaglieri, M
2010-01-01
The CLAS Collaboration is operating the CLAS detector at theThomas Jefferson National Laboratory (JLab) in USA. The unique combination of the detector large acceptance and high intensity of the continuous electron beam of CEBAF has opened the way to a comprehensive study of the hadrons structure in kinematic domain between nuclear and particle physics. Hadron spectroscopy plays a central role in the physics program of the Collaboration. Many exclusive channels have been studied with virtual and real photon beams in a wide kinematic providing key information about the hadron structure as well as the reactions dynamic. In this contribution, the rich physics program covered by present and future experiments will be reviewed.
Hadron physics performed on the stage of nuclei
International Nuclear Information System (INIS)
Jido, Daisuke
2009-01-01
Modern nuclear physics is intended to reveal dynamics of strong interactions of nuclei, hadrons and quarks by covering broad fields extending from nuclear structures to quantum chromodynamics (QCD) phase structures. Strong interactions are described clearly by QCD on the fundamental units of quarks and gluons. In QCD, fundamental degree of freedom is different according to the energy scale due to the asymptotic freedom (strong coupling at low energy), consequently different features of physics are observed. In this lecture, fundamental concept of hadron physics is explained as titled, and an overview of the recent topic of 'Properties of Hadrons in Nuclei' is presented. In the anterior part, chiral symmetry is explained and summarized to supplement the lecture and in the latter part, mesic atoms and nuclei are explained. (S. Funahashi)
Feynman rules of quantum chromodynamics inside a hadron
International Nuclear Information System (INIS)
Lee, T.D.
1979-01-01
We start from quantum chromodynamics in a finite volume of linear size L and examine its color-dielectric constant kappa/sub L/, especially the limit kappa/sub infinity/ as L → infinity. By choosing as our standard kappa/sub L/ = 1 when L = some hadron size R, we conclude that kappa/sub infinity/ must be -2 α where α is the fine-structure constant of QCD inside the hadron. A permanent quark confinement corresponds to the limit kappa/sub infinity/ = 0. The hadrons are viewed as small domain structures (with color-dielectric constant = 1) immersed in a perfect, or nearly perfect, color-dia-electric medium, which is the vacuum. The Feynman rules of QCD inside the hadron are derived; they are found to depend on the color-dielectric constant kappa/sub infinity/ of the vacuum that lies outside. We show that, when kappa/sub infinity/ → 0, the mass of any color-nonsinglet state becomes infinity, but for color-singlet states their masses and scattering amplitudes remain finite. These new Feynman rules also depend on the hadron size R. Only at high energy and large four-momentum transfer can such R dependence be neglected and, for color-singlet states, these new rules be reduced to the usual ones
Hocker, Andreas
1997-01-01
We present new results for the r hadronic spectral functions analysis using data accumulated by the ALEPH detector at LEP during the years 1991-94. The vector and the axial-vector spectral functions are determined from their respective unfolded, i.e., physical invariant mass spectra. The r vector and axial-vector hadronic widths and certain spectral moments are exploited to measure a, and nonperturbative contributions at the r mass scale. The best, and experimentally and theoretically most robust, determination of a,(Mr) is obtained from the inclusive (V + A) fit that yields a,(Mr) = 0.349 ± 0.018 giving a,(Mz) = 0.1 212 ± 0.0022 after the evolution to the mass of the Z boson. The approach of the Operator Product Expansion (OPE) is tested experimentally by means of an evolution of the r hadronic width to masses smaller than the r mass.
Phenomenological studies of hadronic collisions
International Nuclear Information System (INIS)
van Zijl, M.
1987-04-01
Several aspects of hadronic collisions are studied in a phenomenological framework. A Monte Carlo model for initial state parton showers, using a backwards evolution scheme, is presented. Comparisons with experimental data and analytical calculations are made. The consequence of using different fragmentation model on the determination of α s is also investigated. It is found that the different fragmentation models lead to the reconstruction of significantly α s values. Finally the possibility of having several independent parton-parton interactions in a hadron-hadron collision is studied. A model is developed, which takes into account the effects of variable impact parameters. This is implemented in a Monte Carlo computer program and extensive comparisons with experimental data are carried out. There is clear evidence in favour of multiple interactions with variable impact parameters. (author)