Lectures on quantum chromodynamics
Smilga, Andrei
2001-01-01
Quantum chromodynamics is the fundamental theory of strong interactions. It is a physical theory describing Nature. Lectures on Quantum Chromodynamics concentrates, however, not on the phenomenological aspect of QCD; books with comprehensive coverage of phenomenological issues have been written. What the reader will find in this book is a profound discussion on the theoretical foundations of QCD with emphasis on the nonperturbative formulation of the theory: What is gauge symmetry on the classical and on the quantum level? What is the path integral in field theory? How to define the path integ
Experimental tests of quantum chromodynamics
International Nuclear Information System (INIS)
Dorfan, J.
1987-04-01
Experimental tests of quantum chromodynamics are discussed in the e + e - continuum, in pp and anti p p collisions, in measurements of α/sub s/ from Υ decays, in deep inelastic lepton scattering, and in the measurement of the photon structure function. A large body of data relating to the testing of quantum chromodynamics is reviewed, showing qualitative agreement between the data from a wide range of processes and QCD. 66 refs., 79 figs
Hermitian relativity, chromodynamics and confinement
International Nuclear Information System (INIS)
Treder, H.J.
1983-01-01
The extension of the Riemann metrics of General Relativity to the complex domain (substitution of the symmetry conditions for the fundamental tensor, the affinity and the Ricci curvature by the conditions of hermicity) leads to a 'Generalized Theory of Gravity' (Einstein) describing the Newton-Einstein gravodynamics combined with the chromodynamics of quarks. The interaction of gravodynamics and chromodynamics implied by the Einstein-Schroedinger field equations of the hermitian relativity theory enforces the 'confinement'. The 'confinement' prevents the gravitational potential from divergence which would result in the lack of a Riemann space-time metric
Applications of quantum chromodynamics
International Nuclear Information System (INIS)
Field, R.D.
1979-01-01
Perturbative application of the theory of Quantum Chromodynamics (QCQ) are examined and compared with experimental data. Particular emphasis is placed on understanding the similarities and differences between the QCD results and the expectations of the naive parton model
Charmonium and quantum chromodynamics
Vainshtein, A I; Zakharov, V I; Novikov, V A; Okun, Lev Borisovich; Shifman, M A
1977-01-01
The properties of levels of charmonium-the bound system consisting of the charmed quark c and antiquark c-are considered. A brief review is given of the experimental data on the different levels of charmonium, and the classification of the states and their decays are discussed. Of the latter, radiative transitions between levels and the annihilation of levels of charmonium to give photons (or lepton pairs) and also light hadrons ( pi , eta and K mesons), are paid the most attention. Such decays have fundamental significance, inasmuch as they are connected in the most direct manner with the properties of quarks and their interactions. The theoretical foundation of the review is quantum chromodynamics-the theory of the interaction of colored quarks and gluons. The review contains the results of calculations performed in the framework of quantum chromodynamics and pertaining to the annihilation decays of charmonium levels and also to other phenomena: photoproduction of charmed particles, leptonic decays of charm...
Quantum chromodynamics with advanced computing
International Nuclear Information System (INIS)
Kronfeld, A S
2008-01-01
We survey results in lattice quantum chromodynamics from groups in the USQCD Collaboration. The main focus is on physics, but many aspects of the discussion are aimed at an audience of computational physicists
Perturbative tests of quantum chromodynamics
International Nuclear Information System (INIS)
Michael, C.
1978-01-01
A review is given of perturbation theory results for quantum chromodynamics and of tests in deep inelastic lepton scattering, electron-positron annihilation, hadronic production of massive dileptons and hadronic large-momentum-transfer processes. (author)
Introduction to quantum chromodynamics
International Nuclear Information System (INIS)
Shellard, R.C.
1983-06-01
A pedagogical over view of Quantum Chromodynamics, emphasying its pertubative as well as its non pertubative aspects is given. The renormalization group; aplications of QCD to parton models, gauge theories in a lattice, instantons and the theta angle and problems associated to chiral symmetry breaking are studied. (Author) [pt
Neubert, Matthias
1996-01-01
Quantum chromodynamics (QCD) is the fundamental theory of the strong interactions. It is local, non-abelian gauge theory descripting the interactions between quarks and gluons, the constituents of hadrons. In these lectures, the basic concepts and ph will be introduced in a pedagogical way. Topics will include : asymptotically free partons, colour and confinement ; non-abelian gauge invariance and quantization ; the running coupling constant ; deep-inelastic scattering and scaling violations ; th chiral and heavy-quark symmetries. Some elementary knowledge of field theory, abelian gauge invariance and Feynman diagrams will be helpful in following the course.
Two-photon collisions and short-distance tests of quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1978-12-01
The physics of two-photon collisions in e +- storage rings is reviewed with emphasis on the predictions of perturbative quantum chromodynamics for high transverse momentum reactions. It is noted that because of the remarkable scaling properties predicted by the theory, two-photon collisions may be proved one of the cleanest tests of the quantum chromodynamics picture of short distance hadron dynamics. In order to contrast these predictions for photon-induced reactions with those for incident hadrons, predictions from quantum chromodynamics for hadron structure functions and form factors at large momentum transfer are also discussed. 55 references
Classical algebraic chromodynamics
International Nuclear Information System (INIS)
Adler, S.L.
1978-01-01
I develop an extension of the usual equations of SU(n) chromodynamics which permits the consistent introduction of classical, noncommuting quark source charges. The extension involves adding a singlet gluon, giving a U(n) -based theory with outer product P/sup a/(u,v) = (1/2)(d/sup a/bc + if/sup a/bc)(u/sup b/v/sup c/ - v/sup b/u/sup c/) which obeys the Jacobi identity, inner product S (u,v) = (1/2)(u/sup a/v/sup a/ + v/sup a/u/sup a/), and with the n 2 gluon fields elevated to algebraic fields over the quark color charge C* algebra. I show that provided the color charge algebra satisfies the condition S (P (u,v),w) = S (u,P (v,w)) for all elements u,v,w of the algebra, all the standard derivations of Lagrangian chromodynamics continue to hold in the algebraic chromodynamics case. I analyze in detail the color charge algebra in the two-particle (qq, qq-bar, q-barq-bar) case and show that the above consistency condition is satisfied for the following unique (and, interestingly, asymmetric) choice of quark and antiquark charges: Q/sup a//sub q/ = xi/sup a/, Q/sup a//sub q/ = xi-bar/sup a/ + delta/sup a/0(n/2)/sup 3/2/1, with xi/sup a/xi/sup b/ = (1/2)(d/sup a/bc + if/sup a/bc) xi/sup c/, xi-bar/sup a/xi-bar/sup b/ = -(1/2)(d/sup a/bc - if/sup a/bc) xi-bar/sup c/. The algebraic structure of the two-particle U(n) force problem, when expressed on an appropriately diagonalized basis, leads for all n to a classical dynamics problem involving an ordinary SU(2) Yang-Mills field with uniquely specified classical source charges which are nonparallel in the color-singlet state. An explicit calculation shows that local algebraic U(n) gauge transformations lead only to a rigid global rotation of axes in the overlying classical SU(2) problem, which implies that the relative orientations of the classical source charges have physical significance
Perturbative quantum chromodynamics
International Nuclear Information System (INIS)
Reya, E.
1979-12-01
The author gives an introductory lecture into quantum chromodynamics. After a general introduction into the concept of color and a presentation of the QCD Lagrangian the renormalization group and the effective coupling constant are introduced. Then the calculation of deep inelastic lepton-nucleon scattering, scaling violations, factorization at parton distribution, hadronic production of massive lepton pairs and heavy quark flavours, semi-inclusive processes, high-psub(T) reactions, the total hadronic e + e - cross sections, and jets in e + e - annihilation is described. (HSI)
International Nuclear Information System (INIS)
Carson, L.J.
1980-01-01
Quantum chromodynamics (QCD) is currently our only candidate for a theory of strong-interaction dynamics. But the evidence for it is very scanty. Indeed, QCD has only been experimentally verified in its predictions of scaling violation in deep inelastic neutrino scattering. Yet, research continues on QCD because it is based on a beautiful idea, namely the incorporation of observed particle symmetries via local gauge invariance. Nevertheless QCD, a quantum field theory in 3 + 1 dimensions is still without solution. The sheer difficulty in solving the full quantum problem has led some to various approximations, in the hopes of shedding light on the structure of the theory. (orig./FKS)
Light front quantum chromodynamics: Towards phenomenology
Indian Academy of Sciences (India)
Light front dynamics; quantum chromodynamics; deep inelastic scattering. PACS Nos 11.10. ... What makes light front dynamics appealing from high energy phenomenology point of view? .... given in terms of Poincarй generators by. MВ = W P ...
Perturbative quantum chromodynamics
International Nuclear Information System (INIS)
Radyushkin, A.V.
1987-01-01
The latest achievements in perturbative quantum chromodynamics (QCD) relating to the progress in factorization of small and large distances are presented. The following problems are concerned: Development of the theory of Sudakov effects on the basis of mean contour formalism. Development of nonlocal condensate formalism. Calculation of hadron wave functions and hadron distribution functions using QCD method of sum rules. Development of the theory of Regge behaviour in QCD, behaviour of structure functions at small x. Study of polarization effects in hadron processes with high momentum transfer
Construction of two-dimensional quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Klimek, S.; Kondracki, W.
1987-12-01
We present a sketch of the construction of the functional measure for the SU(2) quantum chromodynamics with one generation of fermions in two-dimensional space-time. The method is based on a detailed analysis of Wilson loops.
Relativistic nuclear physics and quantum chromodynamics. Abstracts
International Nuclear Information System (INIS)
1994-01-01
The data of investigations on problems of high energy physics are given. Special attention pays to quantum chromodynamics at large distances, cumulative processes, multiquark states and relativistic nuclear collisions
Perturbative quantum chromodynamics
1989-01-01
This book will be of great interest to advanced students and researchers in the area of high energy theoretical physics. Being the most complete and updated review volume on Perturbative QCD, it serves as an extremely useful textbook or reference book. Some of the reviews in this volume are the best that have been written on the subject anywhere. Contents: Factorization of Hard Processes in QCD (J C Collins, D E Soper & G Sterman); Exclusive Processes in Quantum Chromodynamics (S J Brodsky & G P Lepage); Coherence and Physics of QCD Jets (Yu L Dokshitzer, V A Khoze & S I Troyan); Pomeron in Qu
International Nuclear Information System (INIS)
Isgur, N.
1981-01-01
Many of the phenomenological difficulties of the non-relativistic quark model for baryons are overcome when some current prejudices from chromodynamics about quark forces are imposed. The effects of flavour independent confinement, symmetry breaking through quark masses, and colour hyperfine interactions are most prominent, leading to a satisfactory understanding of both the spectroscopy of low-lying baryons and of the signs and magnitudes of baryon couplings. The previously worrisome absence in partial wave analyses of a large number of the states expected in the nonrelativistic quark model is explained in terms of decouplings of the resonances from their elastic channels
New perspectives in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1993-07-01
In these lectures I will discuss three central topics in quantum chromodynamics: (1) the use of light cone quantization and Fock space methods to determine the long and short-distance structure of quark and gluon distributions within hadrons; (2) the role of spin, heavy quarks, and nuclei in unraveling fundamental phenomenological features of QCD; and (3) a new approach to understanding the scale and scheme dependence of perturbative QCD predictions
Chiral-symmetry breakdown in large-N chromodynamics
International Nuclear Information System (INIS)
Coleman, S.; Witten, E.
1980-01-01
Chromodynamics with n flavors of massless quarks is invariant under chiral U(n) x U(n). It is shown that in the limit of a large number of colors, under reasonable assumptions, this symmetry group must spontaneously break down to diagonal U
Meson spectroscopy, quark mixing and quantum chromodynamics
International Nuclear Information System (INIS)
Filippov, A.T.
1979-01-01
A semiphenomenological theory of mass spectrum for mesons, consisting of a quark-antiquark pair, is presented. Relativistic kinematical effects of the quark mass differences, the SU(3)-symmetry breaking in slopes of the Regge trajectories and in radially excited states are taken into account. The OZI-rule breaking is taken into account by means of the mixing matrix for the quark wave functions, whose form is suggested by the quantum chromodynamics. A simple extrapolation of expression, given by the quantum chromodynamics from the ''asymptotic freedom'' region to the ''infrared slavery'' region is proposed to describe the dependence of the mixing parameters on the meson masses. To calculate masses and mixing angles for pseudoscalar mesons a condition is proposed that the pion mass is minimal. In this situation the eta-meson mass is near the maximal value. The predictions of the theory for masses and mixing angles of the mesons are in good agreement with the experiment
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
Color-charge algebras in Adler's chromodynamics
International Nuclear Information System (INIS)
Cvitanovic, P.; Gonsalves, R.J.; Neville, D.E.
1978-01-01
We show that the color-charge algebra in the three-quark sector generated by the matrices of the fundamental representation of U(n) does not have the trace properties required in Adler's extension of chromodynamics. We also discuss a diagrammatic representation of algebras generated by quark and antiquark charges in general, and an embedding of the N-quark algebra in the symmetric group S/sub N/+1
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.)
Quantum Chromodynamic at finite temperature
International Nuclear Information System (INIS)
Magalhaes, N.S.
1987-01-01
A formal expression to the Gibbs free energy of topological defects of quantum chromodynamics (QCD)by using the semiclassical approach in the context of field theory at finite temperature and in the high temperature limit is determined. This expression is used to calculate the free energy of magnetic monopoles. Applying the obtained results to a method in which the free energy of topological defects of a theory may indicate its different phases, its searched for informations about phases of QCD. (author) [pt
Higher order corrections in perturbative quantum chromodynamics
Indian Academy of Sciences (India)
Since the discovery of asymptotic freedom in non-abelian gauge field theories, like quan- tum chromodynamics (QCD), many perturbative calculations have been performed to ..... The integral above appears in the partial integration with respect to the momentum. &½ of the expression below (see figure 2). ¼. Т&½. ґѕπµТ.
Underlying theory based on quaternions for Alder's algebraic chromodynamics
International Nuclear Information System (INIS)
Horwitz, L.P.; Biedenharn, L.C.
1981-01-01
It is shown that the complex-linear tensor product for quantum quaternionic Hilbert (module) spaces provides an algebraic structure for the non-local gauge field in Adler's algebraic chromodynamics for U
Hadron masses in quantum chromodynamics on the transverse lattice
International Nuclear Information System (INIS)
Bardeen, W.A.; Pearson, R.B.; Rabinovici, E.
1979-09-01
Calculational methods are formulated for the transverse lattice version of quantum chromodynamics. These methods are used to study the low lying spectrum of gluon bound states in the pure Yang-Mills theory. 15 references
Quantum chromodynamics effects in electroweak and Higgs physics
Indian Academy of Sciences (India)
Several examples of the often intricate effects of higher-order quantum chromodynamics (QCD) corrections on predictions for hadron-collider observables, are discussed, using the production of electroweak gauge boson and the Standard Model Higgs boson as examples. Particular attention is given to the interplay of QCD ...
Developments in lattice quantum chromodynamics for matter at high ...
Indian Academy of Sciences (India)
2015-05-06
May 6, 2015 ... Lattice quantum chromodynamics; finite density; sign problem. PACS Nos 11.15. ... Lattice QCD relies on importance sampling assigning a real ..... conjectured that a single saddle point (e.g. the perturbative one) suffices [53].
Progress toward the effective Quantum Chromodynamic Lagrangian from symmetry considerations
International Nuclear Information System (INIS)
Salomone, A.N.
1982-01-01
The properties of an effective Lagrangian which satisfies both the axial and trace anomaly equations of Quantum Chromodynamics are investigated both from the theoretical and phenomenological points of view. The model Lagrangian requires that chiral symmetry be broken spontaneously. The non-linear approximation of the model illuminates eta-glue duality or mixing. The phase transition behavior of the model of Quantum Chromodynamics can be studied as the numbers of flavors and the vacuum angle are varied by analyzing a simple mechanical analog. The analog of the model is similar to the massive Schwinger model. The possibility of a physical scalar glue state is discussed and it is shown that it is characterized by a pronounced eta to two glue decay width. A nonperturbative Quantum Chromodynamic vacuum is seen to follow directly from satisfying the trace anomaly. The quark matter meson, eta, is at least as prominent as the glueball, iota, in the gluon dominated reaction psi to gamma plus anything. An associated large breaking of flavor SU(3) is shown to be ameliorated as the model is made more realistic by lowering scalar meson masses from infinity. The pi delta decay of the iota (1440) can be reasonably well estimated without the need of introducing any new parameters
Lattice quantum chromodynamics equation of state: A better ...
Indian Academy of Sciences (India)
Lattice gauge theory; quantum chromodynamics; finite temperature field theory. ... to a previously underappreciated feature of the plasma phase – that it is far from being a ... setting P = 0 just below Tc and the numerical integration errors. ...... for different temperatures, both above and below Tc. We draw attention to the.
U matrix construction for Quantum Chromodynamics through Dirac brackets
International Nuclear Information System (INIS)
Santos, M.A. dos.
1987-09-01
A procedure for obtaining the U matrix using Dirac brackets, recently developed by Kiefer and Rothe, is applied for Quantum Chromodynamics. The correspondent interaction Lagrangian is the same obtained by Schwinger, Christ and Lee, using independent methods. (L.C.J.A.)
Synthesis of quantum chromodynamics and nuclear physics
International Nuclear Information System (INIS)
Brodsky, S.J.; Lepage, G.P.
1980-08-01
The asymptotic freedom behavior of quantum chromodynamics allows the rigorous calculation of hadronic and nuclear amplitudes at short distances by perturbative methods. The implications of QCD for large-momentum-transfer nuclear form factors and scattering processes, as well as for the structure of nuclear wave functions and nuclear interactions at short distances, are discussed. The necessity for color-polarized internal nuclear states is also discussed. 6 figures
Predictions of quantum chromodynamics of the second order
International Nuclear Information System (INIS)
Kounnas, M.C.
1981-12-01
The model of partons is generalized. Proof of factorization in the region of the large moments of transfer, higher-order corrections in a scalar theory, in non-abelian gauge theories, for single transitions, higher-order effects for structure and fragmentation functions in quantum chromodynamics, analytical solution in the space of the X's are presented [fr
Photon pairs: Quantum chromodynamics continuum and the Higgs ...
Indian Academy of Sciences (India)
is the largest. Results are compared with data from the Fermilab Tevatron and predictions are made for the large hadron collider. The QCD continuum is shown to have a softer spectrum than the Higgs boson signal at the LHC. Keywords. Higgs; photon pairs; quantum chromodynamics. PACS Nos 12.15.Ji; 12.38.Cy; 13.85.
Quantum Chromodynamics and Nuclear Physics at Extreme Energy Density
Energy Technology Data Exchange (ETDEWEB)
Mueller, B.; Bass, S.A.; Chandrasekharan, S.; Mehen, T.; Springer, R.P.
2005-11-07
The report describes research in theoretical quantum chromodynamics, including effective field theories of hadronic interactions, properties of strongly interacting matter at extreme energy density, phenomenology of relativistic heavy ion collisions, and algorithms and numerical simulations of lattice gauge theory and other many-body systems.
Quantum Chromodynamics and Nuclear Physics at Extreme Energy Density
International Nuclear Information System (INIS)
Mueller, B.; Bass, S.A.; Chandrasekharan, S.; Mehen, T.; Springer, R.P.
2005-01-01
The report describes research in theoretical quantum chromodynamics, including effective field theories of hadronic interactions, properties of strongly interacting matter at extreme energy density, phenomenology of relativistic heavy ion collisions, and algorithms and numerical simulations of lattice gauge theory and other many-body systems.
Form factors and charge radii in a quantum chromodynamics ...
Indian Academy of Sciences (India)
tic form factors and charge radii of D, Ds,B,Bs and Bc mesons in a quantum chromodynamics. (QCD)-inspired ... as pointed out in [12,13], one can expect a similar success here too. .... 0 were large and the formalism failed to account for large ...
Phenomenological applications of perturbative quantum chromodynamics
International Nuclear Information System (INIS)
Zahir, M.S.Z.
1981-01-01
In this thesis, three diffrent topics in high energy particle physics are investigated each of which is a case of theoretical and phenomenological application of perturbative Quantum Chromodynamics. The first topic is addressed to the structure of nucleons as probed in deep-inelastic lepton-nucleon scattering. Since, at present, meaningful calculations in Quantum Chromodynamics (QCD) can be done only for short distances or large momentum transfers, phenomenological applications of QCD to the full hadronic processes many a time require additional model dependent procedures. In this thesis, the structure functions of the nucleon in the framework of the valon model in which a nucleon is assumed to be a bound state of three valence quark clusters (valons) are analyzed. In the second topic the production of massive dimuons at large transverse momentum in Drell-Yan process is analyzed where it is believed that the dimuons acquire large transverse momentum through the emission or absorption of hard gluons. Following a model independent formalism, in this thesis, the lowest order QCD contributions to the structure functions in lepton-pair production are calculated and it is shown that there exist sum rules connecting the four sructure functions to be satisfied at zero rapidity and large transverse momentum of the muon-pair for similar interacting hadrons. In the third topic a discussion is given on how high energy photons can replace hadrons in new lepton-pair production process
Quantum chromodynamics, chiral symmetry and bag models
International Nuclear Information System (INIS)
Soyeur, M.
1983-08-01
This course deals with the following subjects: quarks; quantum chromodynamics (the classical Lagrangian of QCD, quark masses, the classical equations of motion of QCD, general properties, lattices); chiral symmetry (massless free Dirac theory, realizations, the σ-model); the M.I.T. bag model (basic assumptions and equations of motion, spherical cavity approximation, properties of hadrons); the chiral bag models (basic assumptions, the cloudy bag model, the little bag model); non-topological soliton bag models
On one approximation in quantum chromodynamics
International Nuclear Information System (INIS)
Alekseev, A.I.; Bajkov, V.A.; Boos, Eh.Eh.
1982-01-01
Form of a complete fermion propagator near the mass shell is investigated. Considered is a nodel of quantum chromodynamics (MQC) where in the fermion section the Block-Nordsic approximation has been made, i. e. u-numbers are substituted for ν matrices. The model was investigated by means of the Schwinger-Dyson equation for a quark propagator in the infrared region. The Schwinger-Dyson equation was managed to reduce to a differential equation which is easily solved. At that, the Green function is suitable to represent as integral transformation
Jet invariant mass in quantum chromodynamics
International Nuclear Information System (INIS)
Clavelli, L.
1979-03-01
We give heuristic argument that a new class of observable related to the invariant mass of jets in e + e - annihilation is infrared finite to all orders of perturbation theory in Quantum Chromodynamics. We calculate the lowest order QCD predictions for the mass distribution as well as for the double differential cross section to produce back to back jets of invariant mass M 1 and M 2 . The resulting cross sections are quite different from that expected in simple hadronic fireball models and should provide experimentally accessible tests of QCD. (orig.) [de
Quantum chromodynamics as dynamics of loops
International Nuclear Information System (INIS)
Makeenko, Yu.; Migdal, A.A.
1980-01-01
The problem of a possibility of reformulating quantum chromodynamics (QCD) in terms of colourless composite fields instead of coloured quarks and gluons is considered. The role of such fields is played by the gauge invariant loop functionals. The Shwinger equations of motion is derived in the loop space which completely describe dynamics of the loop fields. New manifestly gauge invariant diagram technique in the loop space is developed. These diagrams reproduce asymptotic freedom in the ultraviolet range and are consistent with the confinement law in the infrared range
Some views about chromodynamics
International Nuclear Information System (INIS)
Pilon, E.
1995-01-01
The first lesson recalls some basis of quantum chromodynamics (QCD). Particularly the Lagrangian density and the Feynman laws are described. The second lesson presents the problem of renormalization and the notion of efficient coupling. The important property of asymptotic freedom of QCD is detailed. The third lesson gives a schematic classification of processes involved in hadronic physics with high energy-momentum transfer. Scale invariance and its breakdown by using leading log method is presented and leads to the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi equations. The fourth and last lesson paves the way to use the factorization method beyond the leading logs in the case of hadron-hadron collision within the frame of leading twist. Some ideas about comparisons between semi-analytical calculations and Monte-Carlo simulations are given. (A.C.)
Some observations on quantum chromodynamics
International Nuclear Information System (INIS)
t Hooft, G.
1977-01-01
In this treatment of quantum chromodynamics it is argued that the formal series in the coupling constant g diverges badly for all values of g. Due to the renormalization group the series has a direct physical interpretation as an asymptotic expansion for very large (Euclidean) momenta. Although the expansion diverges, the question is whether in combination with physical requirements such as unitarity and causality it does nontheless define a theory uniquely and whether in principle the divergent series can be replaced by a convergent one, no matter how complicated. After a definition of the theory, the complex coupling constant plane for the massless theory and the Borel summation are considered. 14 references
Murray Gell-Mann, the Eightfold Way, Quarks, and Quantum Chromodynamics
. Professor Gell-Mann's "eightfold way" theory brought order to the chaos created by the discovery , Professor Gell-Mann received the Nobel Prize in physics for his work on the theory of elementary particles later constructed the quantum field theory of quarks and gluons, called "quantum chromodynamics
Elements of quantum chromodynamics
International Nuclear Information System (INIS)
Bjorken, J.D.
1979-01-01
The subject of quantum chromodynamics is discussed at length. The introduction motivates the exposition and points out the analogies between QCD and QED. Then, after some assumptions about the nature of QCD, a description is given of what the solution of the theory should look like for three stages of complexity: pure QCD with no fermions or other sources, introduction of superheavy quarks, introduction of the light quarks (u, d, s) with vacuum polarization and pair creation. Next, canonical quantization of QCD by use of a Hamiltonian formulation (in A 0 = 0 gauge) is considered; gauge ambiguities, theta vacua, instantons, etc., are encountered. Then the properties of the three stages noted above are discussed in much greater detail. These follow descriptions of the confinement problem and various approaches to it, as well as of more radical alternatives to QCD, such as the string model or the Pati-Salam program. Included in the summary is an assessment of the current situation. 101 references, 23 figures, 2 tables
Exclusive processes and the exclusive-inclusive connection in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.; Lepage, G.P.
1979-03-01
An outline of a new analysis of exclusive processes and quantum chromodynamics is presented. The main elements of this work involve a consistent Fock space decomposition of the hadronic wave function, plus evolution equations for wave functions which allow an exact evaluation of hadronic matrix elements in the asymptotic short distance limit. 77 references
Clothed Particles in Quantum Electrodynamics and Quantum Chromodynamics
Directory of Open Access Journals (Sweden)
Shebeko Alexander
2016-01-01
Full Text Available The notion of clothing in quantum field theory (QFT, put forward by Greenberg and Schweber and developed by M. Shirokov, is applied in quantum electrodynamics (QED and quantum chromodynamics (QCD. Along the guideline we have derived a novel analytic expression for the QED Hamiltonian in the clothed particle representation (CPR. In addition, we are trying to realize this notion in QCD (to be definite for the gauge group SU(3 when drawing parallels between QCD and QED.
Local gauge symmetry and confinement in quantum chromodynamics
International Nuclear Information System (INIS)
Bardeen, W.A.; Pearson, R.B.
1977-01-01
The nonabelian color gauge theory of quarks and gluons has been proposed as the basis for fundamental theory of hadrons. The features of this theory (quantum chromodynamics) are considered which lead to confinement. A transverse lattice formulation of the theory is also discussed, which is used as a basis for calculation of properties of the hadron bound states. The theory is quantized by eliminating the longitudinal degrees of freedom in favour of coulomb potential. Hadrons are formed as bound states of quarks and the symmetric phase gluons
Quantum electrical and chromodynamics treated through Thompson's approach
International Nuclear Information System (INIS)
Nassif, Claudio; Silva, P.R.
2006-09-01
In this work we apply Thompson's method (of the dimensions and scales) to study some features of the Quantum Electro and Chromodynamics. This heuristic method can be considered as a simple and alternative way to the Renormalisation Group (R.G.) approach and when applied to QED-Lagrangian is able to obtain in a first approximation both the running coupling constant behavior of α(μ) and the mass m(μ). The calculations are evaluated just at d c = 4, where d c is the upper critical dimension of the problem, so that we obtain the logarithmic behavior both for the coupling α and the excess of mass Δm on the energy scale μ. Although our results are well-known in the vast literature of field theories, the advantage of Thompson's method, beyond its simplicity is that it is able to extract directly from QED-Lagrangian the physical (finite) behavior of α(μ) and m(μ), bypassing hard problems of divergences which normally appear in the conventional renormalisation schemes applied to field theories like QED. Quantum Chromodynamics (QCD) is also treated by the present method in order to obtain the quark condensate value. Besides this, the method is also able to evaluate the vacuum pressure at the boundary of the nucleon. This is done by assuming a step function behavior for the running coupling constant of the QCD, which fits nicely to some quantities related to the strong interaction evaluated through the MIT-bag model. (author)
Introduction to non-perturbative quantum chromodynamics
International Nuclear Information System (INIS)
Pene, O.
1995-01-01
Quantum chromodynamics is considered to be the theory of strong interaction. The main peculiarity of this theory is that its asymptotic states (hadrons) are different from its elementary fields (quarks and gluons). This property plays a great part in any physical process involving small momentum-energy transfers. In such a range perturbative methods are no longer allowed. This work focuses on other tools such as QCD symmetry, the quark model, Green functions and the sum rules. To get hadron characteristics numerically, QCD on lattices is used but only in the case of simple process involving no more than one hadron in the initial and final states because of the complexity of the Green function. Some examples using a Monte-Carlo simulation are given. (A.C.)
Charm photoproduction and quantum chromodynamics
International Nuclear Information System (INIS)
Novikov, V.A.; Shifman, M.A.; Vainshtein, A.I.; Zakharov, V.I.
1977-01-01
It is shown that charm photoproduction can be consistently described within asymptotically free field theory. Quantum chromodynamics is used to derive sum rules for the total cross section sigmasub(c)sup(γ) which includes both production of mesons with hidden charm (J/PIS, PIS' and so on) and of charmed particles (pairs DantiD, FantiF and so on). An estimate of sigmasub(c)sup(γ) as a function of energy is given and fast growth is discovered up to energies approximately 1000 GeV. In this energy range sigmasub(c)sup(γ) turns out to be equal to several microbarns. It is argued that measurements of charm photoproduction would give the most direct information on the gluon distribution within a nucleon. All the results are generalized to production of heavier particles containing new quarks. In particular, a simple rescaling law is derived connecting the cross sections for charm and beauty
Quantum chromodynamic quark model study of hadron and few hadron systems
International Nuclear Information System (INIS)
Ji, Chueng-Ryong.
1991-05-01
This report details research progress and results obtained during the one year period December 1, 1990 to November 30, 1991. 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. In compliance with grant requirements the principal investigator, Professor Chueng-Ryong Ji, has conducted a research program addressing theoretical investigations of hadron structure and reactions using quantum chromodynamic quark models. This principal investigator has devoted 50% of his time during the academic year and 100% of his time in the summer. This percent effort will continue for the remaining period of the grant. The new, significant research results are briefly summarized in the following sections. Recent progress has been reported in the renewal/continuation grant proposal just submitted to the Department of Energy. Finally, full, detailed descriptions of completed work can be found in the project publications which are listed at the end of this progress report
Nuclear chromodynamics: applications of QCD to relativistic multiquark systems
International Nuclear Information System (INIS)
Brodsky, S.J.; Ji, C.R.
1984-07-01
We review the applications of quantum chromodynamics to nuclear multiquark systems. In particular, predictions are given for the deuteron reduced form factor in the high momentum transfer region, hidden color components in nuclear wavefunctions, and the short distance effective force between nucleons. A new antisymmetrization technique is presented which allows a basis for relativistic multiquark wavefunctions and solutions to their evolution to short distances. Areas in which conventional nuclear theory conflicts with QCD are also briefly reviewed. 48 references
Nuclear chromodynamics is not the colorization of nuclear physics
International Nuclear Information System (INIS)
Sivers, D.
1988-01-01
The successful description of nuclei in terms of nucleons, deltas and mesons provides an enormous challenge to QCD. It compels us to pursue our theoretical understanding of chromodynamics into the realm of multiple color singlets in order to examine the concept of color saturation. To pursue this theme, we examine the idea of nuclear transparency in the light of models for confinement and describe the formulation of lattice simulations sensitive to exchange forces. 22 refs., 7 figs
Introduction to quantum chromodynamics (QCD) and the physics of jets
International Nuclear Information System (INIS)
Billoire, Alain; Napoly, Olivier.
1980-12-01
These lecture notes constitute an introduction to Quantum Chromodynamics (QCD), theory of strong interactions. After an elementary presentation of the essential theoretical tools (Lagrangian, renormalization group) and of their consequences for QCD (asymptotic freedom, scaling invariance), we use these to study jets in e + e - annihilation. We thus deal with the problem of infrared divergences and, finally, with the one of the indirect experimental detection of the gluon [fr
Signatures of chromodynamics in hadron collisions
International Nuclear Information System (INIS)
Halzen, F.
1979-01-01
The quantum chromodynamics (QCD) describes the interaction of the parton constituents of hadrons (quarks and gluons) via eight colored photons (gluons) interacting with the quarks, and unlike the photons, with each other. The simple picture of Drell-Yan model has made surprising success. The marriage of the old fashion Drell-Yan parton model with QCD has not only made its phenomenological success in the study of lepton pair production, but has allowed to study quantitatively the gluon correction to the model. Information from beam dump and emulsion experiments on charm production is compared with the typical QCD diagram. The results indicate some possible non-perturbative contribution to the photon- and hadron-production of heavy quarks. The definite features of dilepton as well as large transverse momentum data are direct signature of gluons. (Kato, T.)
Is quantum chromodynamics effectively perturbative everywhere
International Nuclear Information System (INIS)
Misra, S.P.; Pati, J.C.
1980-07-01
We have examined the possibility that QCD processes may be well represented effectively by the Born terms even in the infra-red regime. This appears to be possible if we take not only the running coupling constant but also the running quark and gluon masses in the liberated version of quantum chromodynamics. These running masses appear to suppress the higher order loop corrections compared to the Born diagram even when the running coupling constant increases in the infra-red regime. An explicit interpolating form of the running coupling constant from the ultraviolet to the infra-red regime proposed recently is examined in the context of renormalization group equation. The corresponding β function has an essential singularity at g=0, which suggests the non-perturbative nature of the solutions. (author)
Scalar quantum chromodynamics in two dimensions and parton model
International Nuclear Information System (INIS)
Shei, S.S.; Tsao, H.S.
1977-05-01
The SU(N) scalar quantum chromodynamics in two space-time dimensions in the large N limit are studied. This is the model of color gauge fields interacting with scalar quarks. It is found that the consensual properties of the four dimensional QCD, i.e., the infrared slavery, quark confinement, the charmonium picture etc. are all realized. Moreover, the current in this model mimics nicely the behaviors of current in the four dimensional QCD, in contrast to the original model of 't Hooft
Lattice gauge theory approach to quantum chromodynamics
International Nuclear Information System (INIS)
Kogut, J.B.
1983-01-01
The author reviews in a pedagogical fashion some of the recent developments in lattice quantum chromodynamics. This review emphasizes explicit examples and illustrations rather than general proofs and analyses. It begins with a discussion of the heavy-quark potential in continuum quantum chromodynamics. Asymptotic freedom and renormalization-group improved perturbation theory are discussed. A simple dielectric model of confinement is considered as an intuitive guide to the vacuum of non-Abelian gauge theories. Next, the Euclidean form of lattice gauge theory is introduced, and an assortment of calculational methods are reviewed. These include high-temperature expansions, duality, Monte Carlo computer simulations, and weak coupling expansions. A #betta#-parameter calculation for asymptotically free-spin models is presented. The Hamiltonian formulation of lattice gauge theory is presented and is illustrated in the context of flux tube dynamics. Roughening transitions, Casimir forces, and the restoration of rotational symmetry are discussed. Mechanisms of confinement in lattice theories are illustrated in the two-dimensional electrodynamics of the planar model and the U(1) gauge theory in four dimensions. Generalized actions for SU(2) gauge theories and the relevance of monopoles and strings to crossover phenomena are considered. A brief discussion of the continuity of fields and topologial charge in asymptotically free lattice models is presented. The final major topic of this review concerns lattice fermions. The species doubling problem and its relation to chiral symmetry are illustrated. Staggered Euclidean fermion methods are discussed in detail, with an emphasis on species counting, remnants of chiral symmetry, Block spin variables, and the axial anomaly. Numerical methods for including fermions in computer simulations are considered. Jacobi and Gauss-Siedel inversion methods to obtain the fermion propagator in a background gauge field are reviewed
Appropriate definition of the scale parameter Λ in quantum chromodynamics
International Nuclear Information System (INIS)
Monsay, E.; Rosenzweig, C.
1981-01-01
Even after we have chosen a specific definition of the quantum-chromodynamic coupling constant (e.g., modified minimal subtraction or momentum-space subtraction) we are free to choose a definition of Λ when we expand the coupling constant in powers of (lnQ 2 /Λ 2 ) -1 . We discuss in detail a particular definition suggested by Abbott and argue that this definition does seem to provide an attractive means of fixing Λ
Workshop on nuclear chromodynamics: Quarks and gluons in particles and nuclei
International Nuclear Information System (INIS)
Brodsky, S.; Moniz, E.
1985-01-01
The assertion that quantum chromodynamics (QCD) is the correct theory describing strong interaction phenomena has, largely by repetition, become rather non-controversial. It is likely even true. However, whether or not it is correct in detail, the experimentally supported realization that colored quarks and gluons are the elementary degrees of freedom, that asymptotic freedom makes short distance phenomena rather ''simple'' to understand, and that color is confined on the hadronic length scale of -- 1 fm has led to a profound change in the character of our attempts to understand the structure and interactions of both hadrons and nuclei. Many of the most important issued in particle physics and in nuclear physics are now seen to be intimately connected. An understanding of the validity and limits of effective theories based upon hadron degrees of freedom, so phenomenologically successful in describing a host of low energy phenomena, is coming into focus. The existence of new forms of matter grounded in the hidden color degree of freedom is predicted. These considerations form the subject of nuclear chromodynamics (NCD). The subject is far from mature and is developing rapidly
Foundations of quantum chromodynamics: Perturbative methods in gauge theories
International Nuclear Information System (INIS)
Muta, T.
1986-01-01
This volume develops the techniques of perturbative QCD in great detail starting with field theory. Aside from extensive treatments of the renormalization group technique, the operator product expansion formalism and their applications to short-distance reactions, this book provides a comprehensive introduction to gauge field theories. Examples and exercises are provided to amplify the discussions on important topics. Contents: Introduction; Elements of Quantum Chromodynamics; The Renormalization Group Method; Asymptotic Freedom; Operator Product Expansion Formalism; Applications; Renormalization Scheme Dependence; Factorization Theorem; Further Applications; Power Corrections; Infrared Problem. Power Correlations; Infrared Problem
Quantum chromodynamics: A theory of the nuclear force
International Nuclear Information System (INIS)
Craigie, N.S.
1980-06-01
A brief outline is given of a possible theory of the nuclear force and the strong interactions between elementary particles, which is supposed responsible for nuclear matter. The theory is known as quantum chromodynamics because of its association with a new kind of nuclear charge called colour and its resemblance to quantum electrodynamics. Early ideas on the nuclear force and the emergence of the quark model and the QCD Lagrangian are described first. Then properties of this theory and the problem of quark confinement, the perturbative phase of QCD, and the non-perturbative or confinement phase of QCD and the description of hadrons and their interactions are discussed
Spectral function sum rules in quantum chromodynamics. I. Charged currents sector
International Nuclear Information System (INIS)
Floratos, E.G.; Narison, Stephan; Rafael, Eduardo de.
1978-07-01
The Weinberg sum rules of the algebra of currents are reconsidered in the light of quantum chromodynamics (QCD). The authors derive new finite energy sum rules which replace the old Weinberg sum rules. The new sum rules are convergent and the rate of convergence is explicitly calculated in perturbative QCD at the one loop approximation. Phenomenological applications of these sum rules in the charged current sector are also discussed
Novel nuclear phenomena in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1987-08-01
Many of the key issues in understanding quantum chromodynamics involve processes in nuclear targets at intermediate energies. A range of hadronic and nuclear phenomena-exclusive processes, color transparency, hidden color degrees of freedom in nuclei, reduced nuclear amplitudes, jet coalescence, formation zone effects, hadron helicity selection rules, spin correlations, higher twist effects, and nuclear diffraction were discussed as tools for probing hadron structure and the propagation of quark and gluon jets in nuclei. Several areas were also reviewed where there has been significant theoretical progress determining the form of hadron and nuclear wave functions, including QCD sum rules, lattice gauge theory, and discretized light-cone quantization. A possible interpretation was also discussed of the large spin correlation A/sub NN/ in proton-proton scattering, and how relate this effect to an energy and angular dependence of color transparency in nuclei. 76 refs., 24 figs
Scalar quantum chromodynamics in two dimensions and the parton model
International Nuclear Information System (INIS)
Shei, S.S.; Tsao, H.-S.
1978-01-01
SU(N) scalar quantum chromodynamics is studied in two space-time dimensions in the large-N limit. This is the model of color gauge fields interacting with scalar quarks. It is found that the consensual properties of four-dimensional QCD, i.e. infrared slavery, quark confinement, the charmonium picture. etc, are all realized. Moreover, the current in this model mimics nicely the behaviour of the current in four-dimensional QCD, in contrast to the original model of 't Hooft. (Auth.)
Quasi-particles and quantum condensate in the Quantum Chromodynamics
International Nuclear Information System (INIS)
Herrmann, J.
1987-01-01
The non-perturbative structure of Quantum Chromodynamics is investigated with the help of a generalisation of the formalism of Green's functions according to Gorkow and Nambu's studies in the theory of superconductivity methods. Taking into account the existence of the gluon condensation, the self-energy of the gluon-quasi-particles in the form of integral-equations is calculated with the help of modified rules for Feynman diagrams. The form of these equations implies the existence of particular solutions with an energy gap in the spectrum of the quasi-particles and a phase transition at a critical momentum. (author)
Quantum chromodynamics in few-nucleon systems
International Nuclear Information System (INIS)
Brodsky, S.J.
1983-10-01
One of the most important implications of quantum chromodynamics (QCD) is that nuclear systems and forces can be described at a fundamental level. The theory provides natural explanations for the basic features of hadronic physics: the meson and baryon spectra, quark statistics, the structure of the weak and electromagnetic currents of hadrons, the scale-invariance of hadronic interactions at short distances, and evidently, color (i.e., quark and gluon) confinement at large distances. Many different and diverse tests have confirmed the basic predictions of QCD; however, since tests of quark and gluon interactions must be done within the confines of hadrons there have been few truly quantitative checks. Nevertheless, it appears likely that QCD is the fundamental theory of hadronic and nuclear interactions in the same sense that QED gives a precise description of electrodynamic interctions. Topics discussed include exclusive processes in QCD, the deuteron in QCD, reduced nuclear amplitudes, and limitations of traditional nuclear physics. 32 references
Parton densities in quantum chromodynamics gauge invariance, path-dependence and Wilson lines
Cherednikov, Igor O
2016-01-01
The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and loops in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), ab initio techniques are developed and practical tools for their implementation presented. An emphasis is put on their renormalization and on implications on processes observable at experimental facilities.
Quantum chromodynamics and the derivation of a microscopic theory of the nucleus
International Nuclear Information System (INIS)
Sliv, L.A.; Strikman, M.I.; Frankfurt, L.L.
1985-01-01
The progress which has already been made in the construction of a microscopic theory of the nucleus on the basis of quantum chromodynamics, the problems remaining, and the outlook for future progress are analyzed. The problem of nuclear forces, the role played by a high-momentum component in the nuclear wave function, and the role played by relativistic effects in various hard nuclear processes are discussed
Energy correlations in perturbative quantum chromodynamics: a conjecture for all orders
International Nuclear Information System (INIS)
Basham, C.L.; Brown, L.S.; Ellis, S.D.; Love, S.T.
1979-01-01
The hadronic energy produced in high-energy electron-positron annihilation has an angular correlation which can be computed by the asymptotically free perturbation theory of quantum chromodynamics. In finite orders, the correlation is not well behaved as the detectors become anti-collinear. The leading behaviour has been calculated to fourth order and an exponential expression for the sum of all orders is discussed. This expression obeys a non-trivial sum rule which lends support for its validity. (Auth.)
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
Quarks and gluons in the phase diagram of quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Welzbacher, Christian Andreas
2016-07-14
In this dissertation we study the phase diagram of strongly interacting matter by approaching the theory of quantum chromodynamics in the functional approach of Dyson-Schwinger equations. With these quantum (field) equations of motions we calculate the non-perturbative quark propagator within the Matsubara formalism. We built up on previous works and extend the so-called truncation scheme, which is necessary to render the infinite tower of Dyson-Schwinger equations finite and study phase transitions of chiral symmetry and the confinement/deconfinement transition. In the first part of this thesis we discuss general aspects of quantum chromodynamics and introduce the Dyson-Schwinger equations in general and present the quark Dyson-Schwinger equation together with its counterpart for the gluon. The Bethe-Salpeter equation is introduced which is necessary to perform two-body bound state calculations. A view on the phase diagram of quantum chromodynamics is given, including the discussion of order parameter for chiral symmetry and confinement. Here we also discuss the dependence of the phase structure on the masses of the quarks. In the following we present the truncation and our results for an unquenched N{sub f} = 2+1 calculation and compare it to previous studies. We highlight some complementary details for the quark and gluon propagator and discus the resulting phase diagram, which is in agreement with previous work. Results for an equivalent of the Columbia plot and the critical surface are discussed. A systematically improved truncation, where the charm quark as a dynamical quark flavour is added, will be presented in Ch. 4. An important aspect in this investigation is the proper adjustment of the scales. This is done by matching vacuum properties of the relevant pseudoscalar mesons separately for N{sub f} = 2+1 and N f = 2+1+1 via a solution of the Bethe-Salpeter equation. A comparison of the resulting N{sub f} = 2+1 and N{sub f} = 2+1+1 phase diagram indicates
Machine learning action parameters in lattice quantum chromodynamics
Shanahan, Phiala E.; Trewartha, Daniel; Detmold, William
2018-05-01
Numerical lattice quantum chromodynamics studies of the strong interaction are important in many aspects of particle and nuclear physics. Such studies require significant computing resources to undertake. A number of proposed methods promise improved efficiency of lattice calculations, and access to regions of parameter space that are currently computationally intractable, via multi-scale action-matching approaches that necessitate parametric regression of generated lattice datasets. The applicability of machine learning to this regression task is investigated, with deep neural networks found to provide an efficient solution even in cases where approaches such as principal component analysis fail. The high information content and complex symmetries inherent in lattice QCD datasets require custom neural network layers to be introduced and present opportunities for further development.
Cavity quantum chromodynamics in the presence of a classical background field
International Nuclear Information System (INIS)
Gavin, E.J.O.; Viollier, R.D.
1988-01-01
The QCD (quantum chromodynamics) Lagrange density is constructed in which the gluon field has a classical part, using the background field gauge. The conserved currents deriving from the symmetries of this theory are given and used to define boundary conditions on the field operators on the surface of a spherical, static cavity. The field operators are expanded in terms of a complete set of cavity modes that satisfy the boundary conditions and the field equations in the Dirac picture. 13 refs
Quantum electrical and chromodynamics treated through Thompson's approach
Energy Technology Data Exchange (ETDEWEB)
Nassif, Claudio [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mails: cnassifCBPF@yahoo.com.br; Silva, P.R. [Minas Gerais Univ. (UFMG), Belo Horizonte, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Fisica]. E-mail: prsilva@fisica.ufmg.br
2006-09-15
In this work we apply Thompson's method (of the dimensions and scales) to study some features of the Quantum Electro and Chromodynamics. This heuristic method can be considered as a simple and alternative way to the Renormalisation Group (R.G.) approach and when applied to QED-Lagrangian is able to obtain in a first approximation both the running coupling constant behavior of {alpha}({mu}) and the mass m({mu}). The calculations are evaluated just at d{sub c} = 4, where d{sub c} is the upper critical dimension of the problem, so that we obtain the logarithmic behavior both for the coupling {alpha} and the excess of mass {delta}m on the energy scale {mu}. Although our results are well-known in the vast literature of field theories, the advantage of Thompson's method, beyond its simplicity is that it is able to extract directly from QED-Lagrangian the physical (finite) behavior of {alpha}({mu}) and m({mu}), bypassing hard problems of divergences which normally appear in the conventional renormalisation schemes applied to field theories like QED. Quantum Chromodynamics (QCD) is also treated by the present method in order to obtain the quark condensate value. Besides this, the method is also able to evaluate the vacuum pressure at the boundary of the nucleon. This is done by assuming a step function behavior for the running coupling constant of the QCD, which fits nicely to some quantities related to the strong interaction evaluated through the MIT-bag model. (author)
Some views about chromodynamics; Quelques elements de chromodynamique
Energy Technology Data Exchange (ETDEWEB)
Pilon, E. [Ecole Nationale Superieure Agronomique, 31 - Toulouse (France)]|[Ecole Nationale Superieure, LAPP, 74 - Annecy-le-Vieux (France)
1995-12-31
The first lesson recalls some basis of quantum chromodynamics (QCD). Particularly the Lagrangian density and the Feynman laws are described. The second lesson presents the problem of renormalization and the notion of efficient coupling. The important property of asymptotic freedom of QCD is detailed. The third lesson gives a schematic classification of processes involved in hadronic physics with high energy-momentum transfer. Scale invariance and its breakdown by using leading log method is presented and leads to the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi equations. The fourth and last lesson paves the way to use the factorization method beyond the leading logs in the case of hadron-hadron collision within the frame of leading twist. Some ideas about comparisons between semi-analytical calculations and Monte-Carlo simulations are given. (A.C.) 55 refs.
Current-Current Interactions, Dynamical Symmetry - and Quantum Chromodynamics.
Neuenschwander, Dwight Edward, Jr.
Quantum Chromodynamics with massive gluons (gluon mass (TBOND) xm(,p)) in a contact-interaction limit called CQCD (strong coupling g (--->) (INFIN); x (--->) (INFIN)), despite its non-renormalizability and lack of hope of confinement, is nevertheless interesting for at least two reasons. (1) Some authors have suggested a relation between 4-Fermi and Yang-Mills theories. If g/x('2) slavery, perturbative evaluation of QCD in the infrared is a dubious practice. However, if g('2)/x('2) << 1 in CQCD, then the simplest 4-Fermi interaction is dominant, and CQCD admits perturbative treatment, but only in the infrared. With the dominant interaction, a dynamical Nambu-Goldstone realization of chiral symmetry -breaking (XSB) is found. Although in QCD the relation between confinement and XSB is controversial, XSB occurs in CQCD provided confinement is sacrificed.
Simulations of non-relativistic quantum chromodynamics at strong and weak coupling
Shakespeare, Norman Harold
In this thesis heavy quarks are investigated using lattice nonrelativistic quantum chromodynamics (NRQCD). Two major research works are presented. In the first major work, simulations are done for the three quarkonium systems cc¯, bc¯, and bb¯. The hyperfine splittings are computed at both leading and next-to-leading order in the relativistic expansion, using a large number of lattice spacings. A detailed comparison between mean-link and average plaquette tadpole renormalization schemes is undertaken with a number of features favouring the use of mean-links. These include much better scaling behavior of the hyperfine splittings and smaller relativistic corrections to the spin splittings. Signs of a breakdown in the NRQCD expansion are seen when the bare quark mass, in lattice units, falls below about one. In the second work, coefficients for the perturbative expansion of the static quark self energy are extracted from Monte Carlo simulations in the perturbative region of lattice quantum chromodynamics (QCD). A very large systematic study resulted in a major extension of existing methods. Twisted boundary conditions are used to eliminate the effects of zero modes and to suppress tunneling between the degenerate Z3 vacua. The Monte Carlo results are in excellent agreement with analytic perturbation theory, which is known through second order. New results for the third order coefficient are reported. Preliminary work is reported on quark propagators which will be used to measure second order mass renormalizations for NRQCD fermions.
Radiative E1-decay of charmonium 1P1 level within sum rules of quantum chromodynamics
International Nuclear Information System (INIS)
Martynenko, A.P.
1991-01-01
Analysis of radiative decay of 1 P 1 → 1 S 0 + γ charmonium within sum rules of quantum chromodynamics was conducted. The sum rule, taking account of gluon exponential correction, was obtained, and width of Χ → η c + γ decay was calculated
Quarks, QCD [quantum chromodynamics] and the real world of experimental data
International Nuclear Information System (INIS)
Lipkin, H.J.
1987-07-01
The experimental evidence that supports quantum chromodynamics as the theory that describes how the quarks interact is briefly discussed. The indications of the existence of quarks are reviewed, and calculation of hadron masses is discussed. Additional evidence of hadron substructure as seen in the antiproton is reviewed. Arguments for the existence of color as the ''charge'' carried by quarks by which they interact are given. Hadron masses and the hyperfine interaction are presented, followed by more exotic quark systems and a study of multiquark systems. Weak interactions in the quark model are discussed
Solving quantum chromodynamics by discretized light-cone quantization
International Nuclear Information System (INIS)
Pauli, H.C.
1996-01-01
An effective theory for quantum chromodynamics (QCD) is derived analytically and nonperturbatively from the canonical Lagrangian for QCD in three space and one time dimension. The full light-cone QCD-Hamiltonian is mapped identically onto an effective Hamiltonian which acts only in the q anti q-space. A vertex coupling function is resumed to all orders and after renormalization should become the running coupling constant. The final equations are of surprizing simplicity, and are numerically solvable on a small computer. The prescription is given how to derive from these solutions the probability amplitudes for arbitrary gluon and quark-anti-quark composition by quadratures. The method is based on discretized light-cone quantization and the new method of iterated resolvents. The procedure is applicable also to other many-body theories, but the present work specializes to the general aspects of QCD. (orig.)
Measuring the scale parameter of quantum chromodynamics at CHEER
International Nuclear Information System (INIS)
Krauss, L.M.
1981-01-01
The possibility of measuring the scale parameter of quantum chromodynamics, Λsub(s), at CHEER is discussed. Rationale for the measurement of this quantity are given, along with a discussion of the theoretical difficulties involved. The meaurement of the Q 2 dependence of structure functions and their moments, and methods of measuring αsub(s) and its Q 2 evolution, are discussed, and arguments are given for the advantages and disadvantages of going to high Q 2 values at CHEER. It is concluded that while sensitivity to Λ is lowered at high Q 2 , CHEER will, in principle, be able to provide the first clean measurements of Λ, free from almost all the theoretical confusion involved in interpretations of present data
Hadronic distributions and correlations at 'small x' in quantum chromodynamics
International Nuclear Information System (INIS)
Perez Ramos, R.
2006-09-01
We exactly calculate the double and simple inclusive transverse momentum (kt) distributions and the 2-particle momentum correlations inside high energy hadronic jets at the Modified Leading Logarithmic Approximation (MLLA) of Quantum Chromodynamics. We first obtain the exact solution of the evolution equations at 'small x', which we calculate at the so called 'limiting spectrum'. We then generalize this approximation by performing the steepest descent evaluation. Our predictions are in good agreement with data from Tevatron and improve those which have been obtained in the past. The comparison with forthcoming data (Tevatron, LHC) will further test the hypothesis of Local Hadron Parton Duality, and the eventual need to incorporate next-MLLA corrections. (authors)
Strong interactions and quantum chromodynamics at the leading logarithm approximation
International Nuclear Information System (INIS)
Mantrach, A.
1982-11-01
This thesis is a contribution to the study of Quantum Chromodynamics (QCD) at the leading logarithm approximation (LLA). We have used the interpretation of the LLA in terms of the generalized parton model to propose tests of elementary processes of QCD in large transverse momentum photoproduction reactions. We have used the LLA to sum gluon radiation effects induced in high energy hadronic reactions. We have obtained this way a rise of the nucleon-nucleon total cross section of 15 mb from 60 GeV to 540 GeV. We have exploited the existence of a preconfinement transition in the LLA to study scaling violations in the framework of the dual parton model [fr
Strong coupling 1/Nsub(c) expansion in the gluonic sector of lattice quantum chromodynamics
International Nuclear Information System (INIS)
Engels, J.; Montvay, I.
1980-01-01
The vacuum state of gluonic quantum chromodynamics on the lattice is determined up to fifth order in a 1/Nsub(c) expansion (Nsub(c) = number of colours). The vacuum expectation value of the gluon field squared Fsub(aμv)Fsub(a)sup(μv) is deduced. The quark-antiquark and gluon-gluon potential is calculated in the same limit up to the 1/N 3 sub(c) order. (orig.)
Decoupling of heavy quarks in quantum chromodynamics
International Nuclear Information System (INIS)
Bernreuther, W.
1983-01-01
Decoupling of heavy quarks in quantum chromodynamics (QCD) defined by mass-independent renormalization is investigated. The structure of the relations between the parameters of f flavour QCD below a heavy-quark threshold is discussed to all orders in the loop expansion, and the relations are computed to two-loop approximation for the minimal subtraction schemes (MS) and to one-loop approximation for some Weinberg schemes. These matching relations can be used to systematically determine the renormalization group (RG)-invariant parameters of the effective theory in terms of the RG-invariant parameters of the theory which includes the heavy quark, or vice versa. For MS scheme the connection between Λ/sub f/-1 and Λ/sub f/ to two and three loops is given as well as the two-loop connection between the RG-invariant mass parameters of the f-1 and f flavour theory. The effect of heavy quarks on the evolution of the QCQ coupling is of significance for present QCD phenomenology based on next-to-leading-order perturbation theory. This is illustrated with a few examples within the MS scheme
Small parameters in infrared quantum chromodynamics
Peláez, Marcela; Reinosa, Urko; Serreau, Julien; Tissier, Matthieu; Wschebor, Nicolás
2017-12-01
We study the long-distance properties of quantum chromodynamics in the Landau gauge in an expansion in powers of the three-gluon, four-gluon, and ghost-gluon couplings, but without expanding in the quark-gluon coupling. This is motivated by two observations. First, the gauge sector is well described by perturbation theory in the context of a phenomenological model with a massive gluon. Second, the quark-gluon coupling is significantly larger than those in the gauge sector at large distances. In order to resum the contributions of the remaining infinite set of QED-like diagrams, we further expand the theory in 1 /Nc, where Nc is the number of colors. At leading order, this double expansion leads to the well-known rainbow approximation for the quark propagator. We take advantage of the systematic expansion to get a renormalization-group improvement of the rainbow resummation. A simple numerical solution of the resulting coupled set of equations reproduces the phenomenology of the spontaneous chiral symmetry breaking: for sufficiently large quark-gluon coupling constant, the constituent quark mass saturates when its valence mass approaches zero. We find very good agreement with lattice data for the scalar part of the propagator and explain why the vectorial part is poorly reproduced.
Parton densities in quantum chromodynamics. Gauge invariance, path-dependence, and Wilson lines
International Nuclear Information System (INIS)
Cherednikov, Igor O.
2017-01-01
The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and gauge-invariant correlation functions in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), an ab initio methodology is developed and practical tools for its implementation are presented. Emphasis is put on the implications of gauge invariance and path-dependence properties of transverse-momentum dependent parton density functions. The latter are associated with the QCD factorization approach to semi-inclusive hadronic processes, studied at currently operating and planned experimental facilities.
Parton densities in quantum chromodynamics. Gauge invariance, path-dependence, and Wilson lines
Energy Technology Data Exchange (ETDEWEB)
Cherednikov, Igor O. [Antwerpen Univ. (Belgium). Dept. Fysica; Veken, Frederik F. van der [CERN, Geneva (Switzerland)
2017-05-01
The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and gauge-invariant correlation functions in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), an ab initio methodology is developed and practical tools for its implementation are presented. Emphasis is put on the implications of gauge invariance and path-dependence properties of transverse-momentum dependent parton density functions. The latter are associated with the QCD factorization approach to semi-inclusive hadronic processes, studied at currently operating and planned experimental facilities.
International Nuclear Information System (INIS)
Botelho, Luiz C.L.
2004-01-01
We analyze the triviality-quantum decoherence of Euclidean quantum chromodynamics in the gauge invariant quark current sector in the presence of a very strong external white-noise electromagnetic (strength) field within the context of QCD in the 't Hooft limit of a large number of colors
Condensates in quantum chromodynamics and the cosmological constant
Brodsky, Stanley J.; Shrock, Robert
2011-01-01
Casher and Susskind [Casher A, Susskind L (1974) Phys Rev 9:436–460] have noted that in the light-front description, spontaneous chiral symmetry breaking is a property of hadronic wavefunctions and not of the vacuum. Here we show from several physical perspectives that, because of color confinement, quark and gluon condensates in quantum chromodynamics (QCD) are associated with the internal dynamics of hadrons. We discuss condensates using condensed matter analogues, the Anti de Sitter/conformal field theory correspondence, and the Bethe–Salpeter–Dyson–Schwinger approach for bound states. Our analysis is in agreement with the Casher and Susskind model and the explicit demonstration of “in-hadron” condensates by Roberts and coworkers [Maris P, Roberts CD, Tandy PC (1998) Phys Lett B 420:267–273], using the Bethe–Salpeter–Dyson–Schwinger formalism for QCD-bound states. These results imply that QCD condensates give zero contribution to the cosmological constant, because all of the gravitational effects of the in-hadron condensates are already included in the normal contribution from hadron masses.
International Nuclear Information System (INIS)
Botelho, Luiz C.L.
2008-01-01
We analyze the triviality-quantum decoherence of Euclidean quantum chromodynamics in the gauge invariant quark current sector in the presence of an external U (∞) flavor constant charged white noise reservoir. (author)
High energy deep inelastic scattering in perturbative quantum chromodynamics
International Nuclear Information System (INIS)
Wallon, S.
1996-01-01
In this PhD thesis, we deal with high energy Deep Inelastic Scattering in Perturbative Quantum Chromodynamics (QCD). In this work, two main topics are emphasized: The first one deals with dynamics based on perturbative renormalization group, and on perturbative Regge approaches. We discuss the applicability of these predictions, the possibility of distinguishing them in the HERA experiments, and their unification. We prove that the perturbative Regge dynamic can be successfully applied to describe the HERA data. Different observables are proposed for distinguishing these two approaches. We show that these two predictions can be unified in a system of equations. In the second one, unitarization and saturation problems in high energy QCD are discussed. In the multi-Regge approach, equivalent to the integrable one-dimensional XXX Heisenberg spin chain, we develop methods in order to solve this system, based on the Functional Bethe Ansatz. In the dipole model context, we propose a new formulation of unitarity and saturation effects, using Wilson loops. (author)
Current-current interactions, dynamical symmetry-breaking, and quantum chromodynamics
International Nuclear Information System (INIS)
Neuenschwander, D.E. Jr.
1983-01-01
Quantum Chromodynamics with massive gluons (gluon mass triple bond xm/sub p/) in a contact-interaction limit called CQCD (strong coupling g→infinity; x→infinity), despite its non-renormalizability and lack of hope of confinement, is nevertheless interesting for at least two reasons. Some authors have suggested a relation between 4-Fermi and Yang-Mills theories. If g/x 2 much less than 1, then CQCD is not merely a 4-Fermi interaction, but includes 4,6,8 etc-Fermi non-Abelian contact interactions. With possibility of infrared slavery, perturbative evaluation of QCD in the infrared is a dubious practice. However, if g 2 /x 2 much less than 1 in CQCD, then the simplest 4-Fermi interaction is dominant, and CQCD admits perturbative treatment, but only in the infrared. With the dominant interaction, a dynamical Nambu-Goldstone realization of chiral symmetry-breaking (XSB) is found. Although in QCD the relation between confinement and XSB is controversial, XSB occurs in CQCD provided confinement is sacrificed
Introduction to non-perturbative quantum chromodynamics; Introduction a QCD non perturbatif
Energy Technology Data Exchange (ETDEWEB)
Pene, O. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique et Hautes Energies
1995-12-31
Quantum chromodynamics is considered to be the theory of strong interaction. The main peculiarity of this theory is that its asymptotic states (hadrons) are different from its elementary fields (quarks and gluons). This property plays a great part in any physical process involving small momentum-energy transfers. In such a range perturbative methods are no longer allowed. This work focuses on other tools such as QCD symmetry, the quark model, Green functions and the sum rules. To get hadron characteristics numerically, QCD on lattices is used but only in the case of simple process involving no more than one hadron in the initial and final states because of the complexity of the Green function. Some examples using a Monte-Carlo simulation are given. (A.C.) 39 refs.
Discussion of Various Susceptibilities within Thermal and Dense Quantum Chromodynamics
International Nuclear Information System (INIS)
Xu Shu-Sheng; Shi Yuan-Mei; Yang You-Chang; Cui Zhu-Fang; Zong Hong-Shi
2015-01-01
It is commonly accepted that the system undergoes a crossover at high temperature and low chemical potential beyond the chiral limit case, and the properties of the crossover region are important for researchers to understand the nature of strong interacting matters of quantum chromodynamics (QCD). Since at present there is no exact order of parameters of the phase transitions beyond the chiral limit, QCD susceptibilities are widely used as indicators. In this work various susceptibilities are discussed in the framework of Dyson–Schwinger equations. The results show that different kinds of susceptibilities give the same critical end point, which is the bifurcation point of the crossover region and the first order phase transition line of QCD. Nevertheless, different pseudocritical points are found in the temperature axis. We think that defining a critical band is more suitable in the crossover region. (paper)
Current-current interactions, dynamical symmetry-breaking, and quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Neuenschwander, D.E. Jr.
1983-01-01
Quantum Chromodynamics with massive gluons (gluon mass triple bond xm/sub p/) in a contact-interaction limit called CQCD (strong coupling g..-->..infinity; x..-->..infinity), despite its non-renormalizability and lack of hope of confinement, is nevertheless interesting for at least two reasons. Some authors have suggested a relation between 4-Fermi and Yang-Mills theories. If g/x/sup 2/ much less than 1, then CQCD is not merely a 4-Fermi interaction, but includes 4,6,8 etc-Fermi non-Abelian contact interactions. With possibility of infrared slavery, perturbative evaluation of QCD in the infrared is a dubious practice. However, if g/sup 2//x/sup 2/ much less than 1 in CQCD, then the simplest 4-Fermi interaction is dominant, and CQCD admits perturbative treatment, but only in the infrared. With the dominant interaction, a dynamical Nambu-Goldstone realization of chiral symmetry-breaking (XSB) is found. Although in QCD the relation between confinement and XSB is controversial, XSB occurs in CQCD provided confinement is sacrificed.
Functional renormalization group methods in quantum chromodynamics
International Nuclear Information System (INIS)
Braun, J.
2006-01-01
We apply functional Renormalization Group methods to Quantum Chromodynamics (QCD). First we calculate the mass shift for the pion in a finite volume in the framework of the quark-meson model. In particular, we investigate the importance of quark effects. As in lattice gauge theory, we find that the choice of quark boundary conditions has a noticeable effect on the pion mass shift in small volumes. A comparison of our results to chiral perturbation theory and lattice QCD suggests that lattice QCD has not yet reached volume sizes for which chiral perturbation theory can be applied to extrapolate lattice results for low-energy observables. Phase transitions in QCD at finite temperature and density are currently very actively researched. We study the chiral phase transition at finite temperature with two approaches. First, we compute the phase transition temperature in infinite and in finite volume with the quark-meson model. Though qualitatively correct, our results suggest that the model does not describe the dynamics of QCD near the finite-temperature phase boundary accurately. Second, we study the approach to chiral symmetry breaking in terms of quarks and gluons. We compute the running QCD coupling for all temperatures and scales. We use this result to determine quantitatively the phase boundary in the plane of temperature and number of quark flavors and find good agreement with lattice results. (orig.)
Functional renormalization group methods in quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Braun, J.
2006-12-18
We apply functional Renormalization Group methods to Quantum Chromodynamics (QCD). First we calculate the mass shift for the pion in a finite volume in the framework of the quark-meson model. In particular, we investigate the importance of quark effects. As in lattice gauge theory, we find that the choice of quark boundary conditions has a noticeable effect on the pion mass shift in small volumes. A comparison of our results to chiral perturbation theory and lattice QCD suggests that lattice QCD has not yet reached volume sizes for which chiral perturbation theory can be applied to extrapolate lattice results for low-energy observables. Phase transitions in QCD at finite temperature and density are currently very actively researched. We study the chiral phase transition at finite temperature with two approaches. First, we compute the phase transition temperature in infinite and in finite volume with the quark-meson model. Though qualitatively correct, our results suggest that the model does not describe the dynamics of QCD near the finite-temperature phase boundary accurately. Second, we study the approach to chiral symmetry breaking in terms of quarks and gluons. We compute the running QCD coupling for all temperatures and scales. We use this result to determine quantitatively the phase boundary in the plane of temperature and number of quark flavors and find good agreement with lattice results. (orig.)
Chromodynamics of cooperation in finite populations.
Directory of Open Access Journals (Sweden)
Arne Traulsen
2007-03-01
Full Text Available The basic idea of tag-based models for cooperation is that individuals recognize each other via arbitrary signals, so-called tags. If there are tags of different colors, then cooperators can always establish new signals of recognition. The resulting "chromodynamics" is a mechanism for the evolution of cooperation. Cooperators use a secret tag until they are discovered by defectors who then destroy cooperation based on this tag. Subsequently, a fraction of the population manages to establish cooperation based on a new tag.We derive a mathematical description of stochastic evolutionary dynamics of tag-based cooperation in populations of finite size. Benefit and cost of cooperation are given by b and c. We find that cooperators are more abundant than defectors if b/c > 1+2u/v, where u is the mutation rate changing only the strategy and v is the mutation rate changing strategy and tag. We study specific assumptions for u and v in two genetic models and one cultural model.In a genetic model, tag-based cooperation only evolves if a gene encodes both strategy and tag. In a cultural model with equal mutation rates between all possible phenotypes (tags and behaviors, the crucial condition is b/c > (K+1/(K-1, where K is the number of tags. A larger number of tags requires a smaller benefit-to-cost ratio. In the limit of many different tags, the condition for cooperators to have a higher average abundance than defectors becomes b > c.
Detailed quantum-chromodynamic predictions for high-p/sub T/ processes
Owens, J F; Reya, E
1978-01-01
High-p/sub T/ single-particle inclusive cross section calculations are presented for the CERN ISR and ISABELLE energy ranges, taking into account all lowest-order hard-scattering subprocesses required by quantum chromodynamics (QCD). The input quark and gluon distribution and fragmentation functions were determined from analyses of deep- inelastic lepton data and were subject to various theoretical constraints such as sum rules and SU(3) symmetry. The authors thoroughly discuss the effects of the individual contributions from fermionic and gluonic subprocesses, as well as those effects stemming from QCD scaling violations in parton distributions and/or fragmentation functions. In particular, the inclusion of the large elastic gluon-gluon and gluon-quark scattering terms has a profound effect on both the normalization and the p/sub T/ dependence of the predictions. The p/sub T/ and theta dependences of single- pi /sup 0/ production are shown to be in good agreement with available data in the region p/sub T/>or...
Perturbative quantum chromodynamic analysis of deep inelastic scattering
International Nuclear Information System (INIS)
Herrod, R.T.
1982-01-01
This is an account of the field theoretic description of the deep inelastic scattering of leptons from nucleons. Starting from simple parton model description, using the assumption of an SU(3) colour confining field theory, for the quarks comprising hadronic matter, the well known prediction of Bjorken scaling is obtained. Field theoretic predictions for deviations from Bjorken scaling are formally introduced, with particular reference to quantum chromodynamics (QCD). This treatment is purely perturbative, although the renormalisation group is used to improve convergence. Scaling violations at both leading order, and next-to-leading order are discussed, and it is shown how these lead to predictions regarding the dependence of the moments of observable structure functions, on the square of the 4-momentum transferred (Q 2 ). Evolution equations for the moments of structure functions are then derived. The intuitive approach of Altarelli and Parisi (AP), which leads to predictions for the Q 2 dependence of the structure functions themselves, is introduced. The corresponding equations are derived to next-to-leading order. The results of an extensive analysis of current data are presented.. Both weak and electromagnetic structure functions are compared with the predictions of leading order, and higher order formulae. Methods for incorporating heavy quark flavours into the AP equations are discussed. (author)
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
Interactions of heavy quarks in quantum chromodynamics
International Nuclear Information System (INIS)
Dine, M.
1978-01-01
The interactions of heavy quarks in quantum chromodynamics (QCD) are analyzed in detail. The problem of extracting instantaneous interaction potentials from quantum field theory is first reviewed, in the context of simple models. How such a potential for a fermion-antifermion system may be extracted is indicated. After a review of the quantization of non-Abelian gauge theories in Coulomb gauge, the interaction of a heavy quark-antiquark (Q anti Q) pair is considered. A Ward identity relating the Coulomb-gluon-fermion vertex to the fermion self-energy is derived. This identity is used to prove the mass independence of the static potential. The potential is shown to be infrared finite through two loops, and its general structure in perturbation theory is indicated. At three loops, divergences associated with long-lived intermediate states appear. A method to resolve this problem for static sources is given, but the result cannot readily be identified as a potential appropriate to the description of a Q anti Q bound state. This problem is discussed in detail. Then the spin-dependent interactions in these systems are analyzed. It is shown that the spin-dependent potentials depend in a nontrivial way on the quark mass. The phenomenological implications of these results are considered. In conclusion, the implications of the results for nonperturbative attacks on the potential problem are discussed. The importance of source-field correlations is stressed. The limitations of schemes introduced recently to compute spin-dependent forces due to instantons are illustrated
Lattice analysis of SU(2) chromodynamics with light quarks
International Nuclear Information System (INIS)
Laermann, E.
1986-01-01
I report on the Monte-Carlo simulation of a SU(2) lattice gauge theory which includes dynamical Kogut-Susskind quarks. On a 16*8 3 lattice the masses of ρ and π mesons are studied, the condensate measuring the chiral symmetry breaking determined, and the potential between static quarks measured. Extrapolations to vanishing quark mass yield a finite ρ mass but a value for the π mass which is compatible with zero, as well as a result different from zero for the quark condensate in accordance with the spontaneous breaking of the chiral symmetry of massless non-Abelian gauge theories. The shape of the q-anti q potential equals the pure gauge potential for small to intermediate distances. However at large distances (σ(fm)) deviations from the linear increase are indicated as they are expected due to the breakup of the flux tube between heavy quarks because of spontaneous quark-pair production. For all numerical calculations it is common that they favor a value for the scale parameter Λsub(anti Manti S)(N F =4) of quantum chromodynamics which is smaller than in the pure gauge field theory. (orig.) [de
Statistical mechanics view of quantum chromodynamics: Lattice gauge theory
International Nuclear Information System (INIS)
Kogut, J.B.
1984-01-01
Recent developments in lattice gauge theory are discussed from a statistial mechanics viewpoint. The basic physics problems of quantum chromodynamics (QCD) are reviewed for an audience of critical phenomena theorists. The idea of local gauge symmetry and color, the connection between statistical mechanics and field theory, asymptotic freedom and the continuum limit of lattice gauge theories, and the order parameters (confinement and chiral symmetry) of QCD are reviewed. Then recent developments in the field are discussed. These include the proof of confinement in the lattice theory, numerical evidence for confinement in the continuum limit of lattice gauge theory, and perturbative improvement programs for lattice actions. Next, we turn to the new challenges facing the subject. These include the need for a better understanding of the lattice Dirac equation and recent progress in the development of numerical methods for fermions (the pseudofermion stochastic algorithm and the microcanonical, molecular dynamics equation of motion approach). Finally, some of the applications of lattice gauge theory to QCD spectrum calculations and the thermodynamics of QCD will be discussed and a few remarks concerning future directions of the field will be made
An equation-of-state-meter of quantum chromodynamics transition from deep learning.
Pang, Long-Gang; Zhou, Kai; Su, Nan; Petersen, Hannah; Stöcker, Horst; Wang, Xin-Nian
2018-01-15
A primordial state of matter consisting of free quarks and gluons that existed in the early universe a few microseconds after the Big Bang is also expected to form in high-energy heavy-ion collisions. Determining the equation of state (EoS) of such a primordial matter is the ultimate goal of high-energy heavy-ion experiments. Here we use supervised learning with a deep convolutional neural network to identify the EoS employed in the relativistic hydrodynamic simulations of heavy ion collisions. High-level correlations of particle spectra in transverse momentum and azimuthal angle learned by the network act as an effective EoS-meter in deciphering the nature of the phase transition in quantum chromodynamics. Such EoS-meter is model-independent and insensitive to other simulation inputs including the initial conditions for hydrodynamic simulations.
International Nuclear Information System (INIS)
Hagiwara, K.
1982-01-01
It is argued that the 't Hooft transformation of the running coupling constant, in which the two-loop renormalization group (RG) function becomes exact, will be useful in the framework of perturbative quantum chromodynamics at least to three-loop order. On the other hand, the coupling constant expansion obtained by the Adler transformation, in which the RG equation takes its one-loop form, may suffer from large corrections in a finite order. (orig.)
Boku, Taisuke; Ishikawa, Ken-Ichi; Kuramashi, Yoshinobu; Meadows, Lawrence
2017-01-01
Lattice Quantum Chromodynamics (Lattice QCD) is a quantum field theory on a finite discretized space-time box so as to numerically compute the dynamics of quarks and gluons to explore the nature of subatomic world. Solving the equation of motion of quarks (quark solver) is the most compute-intensive part of the lattice QCD simulations and is one of the legacy HPC applications. We have developed a mixed-precision quark solver for a large Intel Xeon Phi (KNL) system named "Oakforest-PACS", empl...
The black book of quantum chromodynamics a primer for the LHC era
Campbell, John; Krauss, Frank
2018-01-01
The Black Book of Quantum Chromodynamics is an in-depth introduction to the particle physics of current and future experiments at particle accelerators. The book offers the reader an overview of practically all aspects of the strong interaction necessary to understand and appreciate modern particle phenomenology at the energy frontier. It assumes a working knowledge of quantum field theory at the level of introductory textbooks used for advanced undergraduate or in standard postgraduate lectures. The book expands this knowledge with an intuitive understanding of relevant physical concepts, an introduction to modern techniques, and their application to the phenomenology of the strong interaction at the highest energies. Aimed at graduate students and researchers, it also serves as a comprehensive reference for LHC experimenters and theorists. This book offers an exhaustive presentation of the technologies developed and used by practitioners in the field of fixed-order perturbation theory and an overview of re...
International Nuclear Information System (INIS)
Ji, C.R.
1999-01-01
This report details research progress and results obtained during the entire period of the research project. In compliance with grant requirements the Principal Investigator, Professor Chueng-Ryong Ji, has conducted a research program addressing theoretical investigations of hadron structure and reactions using quantum chromodynamic quark models. This Principal Investigator has devoted 50% of his time during the academic year and 100% of his time in the summer. This percent effort has continued during the entire period of the grant. The new, significant research results are briefly summarized in this report. Finally, full, detailed descriptions of completed work can be found in the project publications which are listed at the end of this technical report
International Nuclear Information System (INIS)
Frishman, Y.; Zakrewski, W.J.
1989-07-01
We derive explicit expressions for the masses and the binding energies of k-baryons states in two dimensional (one space and one time) Quantum Chromodynamics (QCD(2)). The expressions are given using the parameters n 1 ,n 2 ,...,nN f -1 which characterize the representation of SU(N f ), where N f is the number of flavours, in terms of its Young tableau description. We find that the difference between the mass of the k-baryon state and the sum of masses of any combination of its constituents, is independent of the value N f (ie the number of flavors). These results hold within a certain bosonized form of QCD(2) and within the strong coupling limit of (G/m) → ∞, where G is the gauge coupling constant and m the quark mass. (authors)
International Nuclear Information System (INIS)
Muzinich, I.J.
1980-01-01
The quark model of hadrons, when all constituents and gluons are included, has the possibility of accommodating not only what are conventionally accepted quark model states but also exotics of various kinds and eventually nuclei themselves. Recently, a considerable theoretical framework has evolved around quarks and gluons known as quantum chromodynamics. This theory is still at a primitive level as far as our ability to perform calculations. However, it is the only possible field theory that contains any hope of understanding both quark freedom at high energies and their strong binding within hadrons. I present a possible viewpoint on how both features could be true without apparent conflict. I also make some speculation on the nature of the perturbation expansion in such a world. What these speculations lack in originally I hope is compensated for by clarity
Parallelizing the QUDA Library for Multi-GPU Calculations in Lattice Quantum Chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Ronald Babich, Michael Clark, Balint Joo
2010-11-01
Graphics Processing Units (GPUs) are having a transformational effect on numerical lattice quantum chromodynamics (LQCD) calculations of importance in nuclear and particle physics. The QUDA library provides a package of mixed precision sparse matrix linear solvers for LQCD applications, supporting single GPUs based on NVIDIA's Compute Unified Device Architecture (CUDA). This library, interfaced to the QDP++/Chroma framework for LQCD calculations, is currently in production use on the "9g" cluster at the Jefferson Laboratory, enabling unprecedented price/performance for a range of problems in LQCD. Nevertheless, memory constraints on current GPU devices limit the problem sizes that can be tackled. In this contribution we describe the parallelization of the QUDA library onto multiple GPUs using MPI, including strategies for the overlapping of communication and computation. We report on both weak and strong scaling for up to 32 GPUs interconnected by InfiniBand, on which we sustain in excess of 4 Tflops.
Parallelizing the QUDA Library for Multi-GPU Calculations in Lattice Quantum Chromodynamics
International Nuclear Information System (INIS)
Babich, Ronald; Clark, Michael; Joo, Balint
2010-01-01
Graphics Processing Units (GPUs) are having a transformational effect on numerical lattice quantum chromodynamics (LQCD) calculations of importance in nuclear and particle physics. The QUDA library provides a package of mixed precision sparse matrix linear solvers for LQCD applications, supporting single GPUs based on NVIDIA's Compute Unified Device Architecture (CUDA). This library, interfaced to the QDP++/Chroma framework for LQCD calculations, is currently in production use on the '9g' cluster at the Jefferson Laboratory, enabling unprecedented price/performance for a range of problems in LQCD. Nevertheless, memory constraints on current GPU devices limit the problem sizes that can be tackled. In this contribution we describe the parallelization of the QUDA library onto multiple GPUs using MPI, including strategies for the overlapping of communication and computation. We report on both weak and strong scaling for up to 32 GPUs interconnected by InfiniBand, on which we sustain in excess of 4 Tflops.
Spectral functions in quantum chromodynamics and applications
International Nuclear Information System (INIS)
Tran, M.D.
1981-01-01
The longitudinal and transverse spectral functions for arbitrary conserved and non-conserved vector and axial vector currents of massive quarks are calculated to first order in α/sub s/ and exact analytical expressions are given. As an intermediate step the form factors to the same order in α/sub s/ are determined. A remarkably simple result for the combination of the spectral functions corresponding to the Weinberg's first sum rule is derived. It behaves asymptotically like α/sub s/s 2 thus ensuring the convergence of the sum rule. The Weinberg's second sum rule is shown to fail to hold, a new sum rule is then proposed to replace the original one. The current algebra calculation of the pion electromagnetic mass difference is reexamined in the light of quantum chromodynamics. The old analysis cannot be upheld because of the failure of the Weinberg's second sum rule. After a modification based on Dashen's theorem, the proposed sum rule then can be used to obtain a mass difference close to experimental value. Using the derived QCD corrected spectral functions on finite Q 2 sum rules, the current couplings of the five low-lying mesons π, rho, K, K*, A 1 are computed. For values of quark masses m/sub u/ = m/sub d/ = 0.25 GeV, m/sub s/ = 0.4 GeV and of the QCD scale parameter Λ = 0.5 GeV, a striking agreement with experiment is obtained. We investigate decay properties of the intermediate vector bosons Z, W. Gluonic corrections to hadronic decay modes are calculated with the account of quark mass effect. Implications of the results for decay widths, branching ratios are examined. The ratio R of reaction e + e - → hadrons is calculated to first order in α/sub s/, the quark mass effect is shown to be important
Searching for new physics at the frontiers with lattice quantum chromodynamics.
Van de Water, Ruth S
2012-07-01
Numerical lattice-quantum chromodynamics (QCD) simulations, when combined with experimental measurements, allow the determination of fundamental parameters of the particle-physics Standard Model and enable searches for physics beyond-the-Standard Model. We present the current status of lattice-QCD weak matrix element calculations needed to obtain the elements and phase of the Cabibbo-Kobayashi-Maskawa (CKM) matrix and to test the Standard Model in the quark-flavor sector. We then discuss evidence that may hint at the presence of new physics beyond the Standard Model CKM framework. Finally, we discuss two opportunities where we expect lattice QCD to play a pivotal role in searching for, and possibly discovery of, new physics at upcoming high-intensity experiments: rare decays and the muon anomalous magnetic moment. The next several years may witness the discovery of new elementary particles at the Large Hadron Collider (LHC). The interplay between lattice QCD, high-energy experiments at the LHC, and high-intensity experiments will be needed to determine the underlying structure of whatever physics beyond-the-Standard Model is realized in nature. © 2012 New York Academy of Sciences.
Factorization of exclusive processes in perturbative quantum-chromodynamics
International Nuclear Information System (INIS)
Segond, M.
2007-12-01
The work carried out in this thesis presents various theoretical and phenomenological studies of the exclusive production of longitudinally polarized neutral vector rho mesons in virtual photons collisions, within the framework of quantum-chromodynamics (QCD). The virtuality of the photons makes it possible to locate our approach in the perturbative area of the theory. The kinematical regimes considered allow the use of varied theoretical tools which reveal various properties of factorization of the scattering amplitude: two types of collinear factorization (at short distance) for this process are discussed in chapter 1, revealing - according to the polarization of the virtual photons and the kinematical limit considered- Generalized Distribution Amplitudes (GDA) or Transition Distribution Amplitudes (TDA), tools commonly used in the description of exclusive processes. We introduce into the Chapter 2 in a self-consistent way, the foundations of the BFKL (Balitskii, Fadin, Kuraev and Lipatov) formalism valid within the high energy limit (Regge limit) of QCD, for its phenomenological use detailed in Chapter 3: the scattering amplitude of the process is described in this formalism by exploiting the factorization in the two-dimensional transverse momentum space, or kT-factorization. We predict the value of the cross section of the process at Born order of the BFKL resummation and we discuss its possible observation at the future international linear collider (ILC). We consider also the differential cross sections of the process without momentum transfer with complete BFKL evolution at the order of the leading logarithms (Leading-Order) and also at the Next-to-Leading-Order to establish a fine test of this process with hard BFKL Pomeron exchange, observable at the future ILC. (author)
International Nuclear Information System (INIS)
Randriamisy, H.D.E.
2014-01-01
Nowadays, the study of scattering and production of particles occupies an important place in subatomic physics research. The main ongoing experiments concern high-energy scattering in the colliders, the scattering theory based on quantum field theory is used for the theoretical study. The work presented in this thesis is located in this framework, in fact it concerns a study on the scattering theory and Perturbative Quantum Chromodynamics. We used the path integral formalism of quantum field theory and perturbation theory. As we considered the higher order corrections in perturbative developments, the renormalization theory with the method of dimensional regularization was also used. As an application, the case of the Top quark production was considered. As main results, we can quote the obtention of the cross section of quark-antiquark top pair production up to second order. [fr
Energy Technology Data Exchange (ETDEWEB)
Deta, U. A., E-mail: utamaalan@yahoo.co.id [Theoretical Physics Group, Physics Department of Post Graduate Program, Sebelas Maret University, Jl. Ir. Sutami 36A, Surakarta 57126, Indonesia and Physics Department, State University of Surabaya, Jl. Ketintang, Surabaya 60231 (Indonesia); Suparmi,; Cari,; Husein, A. S.; Yuliani, H.; Khaled, I. K. A.; Luqman, H.; Supriyanto [Theoretical Physics Group, Physics Department of Post Graduate Program, Sebelas Maret University, Jl. Ir. Sutami 36A, Surakarta 57126 (Indonesia)
2014-09-30
The Energy Spectra and Wave Function of Schrodinger equation in D-Dimensions for trigonometric Rosen-Morse potential were investigated analytically using Nikiforov-Uvarov method. This potential captures the essential traits of the quark-gluon dynamics of Quantum Chromodynamics. The approximate energy spectra are given in the close form and the corresponding approximate wave function for arbitrary l-state (l ≠ 0) in D-dimensions are formulated in the form of differential polynomials. The wave function of this potential unnormalizable for general case. The wave function of this potential unnormalizable for general case. The existence of extra dimensions (centrifugal factor) and this potential increase the energy spectra of system.
Properties of quark matter governed by quantum chromodynamics. Pt. 2
International Nuclear Information System (INIS)
Soni, V.
1983-01-01
Renormalization schemes are examined (in the Coulomb gauge) for quantum chromodynamics in the presence of quark matter. We demand that the effective coupling constant for all schemes become congruent with the vacuum QCD running coupling constant as the matter chemical potential, μ, goes to zero. Also, to enable us to standardize with the vacuum QCD running coupling constant at some asymptotic momentum transfer, vertical strokep 0 vertical stroke, we keep μ 0 vertical stroke, to ensure that the matter contribution is negligible at this point. This means all schemes merge with vacuum QCD at vertical strokep 0 vertical stroke and beyond. Two renormalization group invariants are shown to emerge: (I) the effective or invariant charge, gsub(inv) 2 , which is, however, scheme dependent and (II) g 2 (M)/S(M), where S(M) - 1 is the Coulomb propagator, which is scheme independent. The only scheme in which gsub(inv) 2 is scheme independent and identical to g 2 (M)/S(M) is the screened charged scheme (previous paper) characterised by the normalization of the entire Green function, S - 1 , to unity. We conclude that this is the scheme to be used if one wants to identify with the experimental effective coupling in perturbation theory. However, if we do not restrict to perturbation theory all schemes should be allowed. Although we discuss matter QCD in the Coulomb gauge, the above considerations are quite general to gauge theories in the presence of matter. (orig.)
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
Multi-Hadron Observables from Lattice Quantum Chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Hansen, Maxwell [Univ. of Washington, Seattle, WA (United States)
2014-01-01
We describe formal work that relates the nite-volume spectrum in a quantum eld theory to scattering and decay amplitudes. This is of particular relevance to numerical calculations performed using Lattice Quantum Chromodynamics (LQCD). Correlators calculated using LQCD can only be determined on the Euclidean time axis. For this reason the standard method of determining scattering amplitudes via the Lehmann-Symanzik-Zimmermann reduction formula cannot be employed. By contrast, the nite-volume spectrum is directly accessible in LQCD calculations. Formalism for relating the spectrum to physical scattering observables is thus highly desirable. In this thesis we develop tools for extracting physical information from LQCD for four types of observables. First we analyze systems with multiple, strongly-coupled two-scalar channels. Here we accommodate both identical and nonidentical scalars, and in the latter case allow for degenerate as well as nondegenerate particle masses. Using relativistic eld theory, and summing to all orders in perturbation theory, we derive a result relating the nite-volume spectrum to the two-to-two scattering amplitudes of the coupled-channel theory. This generalizes the formalism of Martin L uscher for the case of single-channel scattering. Second we consider the weak decay of a single particle into multiple, coupled two-scalar channels. We show how the nite-volume matrix element extracted in LQCD is related to matrix elements of asymptotic two-particle states, and thus to decay amplitudes. This generalizes work by Laurent Lellouch and Martin L uscher. Third we extend the method for extracting matrix elements by considering currents which insert energy, momentum and angular momentum. This allows one to extract transition matrix elements and form factors from LQCD. Finally we look beyond two-particle systems to those with three-particles in asymptotic states. Working again to all orders in relativistic eld theory, we derive a relation between the
International Nuclear Information System (INIS)
Hazarika, Bhaskar Jyoti; Choudhury, D.K.
2015-01-01
We use variationally improved perturbation theory (VIPT) for calculating the elastic form factors and charge radii of D, D s , B, B s and B c mesons in a quantum chromodynamics (QCD)-inspired potential model. For that, we use linear-cum-Coulombic potential and opt the Coulombic part first as parent and then the linear part as parent. The results show that charge radii and form factors are quite small for the Coulombic parent compared to the linear parent. Also, the analysis leads to a lower as well as upper bounds on the four-momentum transfer Q 2 , hinting at a workable range of Q 2 within this approach, which may be useful in future experimental analyses. Comparison of both the options shows that the linear parent is the better option. (author)
Lattice quantum chromodynamics and properties of the nucleon
International Nuclear Information System (INIS)
Baron, R.
2009-09-01
The goal of this thesis is to compute from first principles nucleon properties, starting from the microscopic theory of strong interaction, quantum chromodynamics (QCD). This theory, whose degrees of freedom are quarks and gluons, has been well tested in high energy experiments thanks to asymptotic freedom, the fact that interaction cancels at short distances, which allows the use of the perturbative theory. To predict properties which involve long distances, like masses or current distributions, one needs an exact treatment of the theory. It uses a four-dimensional lattice on which the theory is discretized and quantum observables are computed through path integral techniques, as explained in chapters 2 and 3. In chapter 4 we discuss problems faced when fermions are taken into account and we present the choice for our computations: a discretization in a 'Wilson' manner plus an additional twisted mass. Its advantage is to remove discretization effects of the order of the lattice spacing provided one parameter is tuned. The numerical evaluation of path integrals is done by Monte Carlo methods with importance sampling. The 'Hybrid Monte Carlo' algorithm, based on molecular dynamics, is presented in chapter 5 together with a method to solve large sparse linear systems necessary to compute observables. This chapter also describes computer science details of the problem which are the use of massive parallel processing and some characteristics of computers used. In chapter 6 we explain how the production of representative samples of gauge configuration is performed. This step and its control is an important part of the work done during this thesis. The last two chapters are devoted to the computation of observables and to the presentation of results. The main technical difficulty which is to solve for quark propagators has been performed by using available processor farms at their best. A good part of this work has been focused on this. To conclude we comment on the
Gauge invariant description of heavy quark bound states in quantum chromodynamics
International Nuclear Information System (INIS)
Moore, S.E.
1980-08-01
A model for a heavy quark meson is proposed in the framework of a gauge-invariant version of quantum chromodynamics. The field operators in this formulation are taken to be Wilson loops and strings with quark-antiquark ends. The fundamental differential equations of point-like Q.C.D. are expressed as variational equations of the extended loops and strings. The 1/N expansion is described, and it is assumed that nonleading effects such as intermediate quark pairs and nonplanar gluonic terms can be neglected. The action of the Hamiltonian in the A 0 = 0 gauge on a string operator is derived. A trial meson wave functional is constructed consisting of a path-averaged string operator applied to the full vacuum. A Gaussian in the derivative of the path location is assumed for the minimal form of the measure over paths. A variational parameter is incorporated in the measure as the exponentiated coefficient of the squared path location. The expectation value of the Hamiltonian in the trial state is evaluated for the assumption that the negative logarithm of the expectation value of a Wilson loop is proportional to the loop area. The energy is then minimized by deriving the equivalent quantum mechanical Schroedinger's equation and using the quantum mechanical 1/n expansion to estimate the effective eigenvalues. It is found that the area law behavior of the Wilson loop implies a nonzero best value of the variational parameter corresponding to a quantum broadening of the flux tube
Quantum chromodynamics on the lattice
International Nuclear Information System (INIS)
Kovacs, T.G.; Pittler, F.
2012-01-01
Complete text of publication follows. Quantum chromodynamics (QCD) is the generally accepted theory of the strong interactions that bind quarks into hadrons like the proton and the neutron. The only systematic way of computing low-energy observables starting from the theory is to discretize it on a space-time lattice and perform large-scale Monte Carlo numerical simulations. In the past years lattice QCD did not only provide more and more precise numerical data to be compared to experimental data but also contributed to a better intuitive understanding of the phenomena occurring in strongly interacting systems. One of the most interesting of these phenomena is the transition of ordinary strongly interacting matter to the so called quark-gluon plasma phase occurring at high temperature and already observed in heavy ion collisions. Quarks that are all confined into hadrons at low temperature become liberated above the critical temperature characterizing the transition. At the same time the chiral symmetry that is spontaneously broken at low temperatures also gets restored. Chiral symmetry is intimately connected to the density of low-lying quark states. At low temperature these states are known to follow Wigner-Dyson random matrix statistics. This has been successfully exploited to compute the parameters of the effective chiral Lagrangian describing strongly interacting systems in the low energy limit. In contrast, up to a few years ago there was no generally accepted understanding of the statistical properties of lowlying quark states above the critical temperature. We showed that in simplified models of QCD the low quark eigenmodes obey Poisson statistics that gradually crosses over to Wigner-Dyson statistics higher up in the spectrum. This also implies that the low modes are highly localized which can have significant physical consequences. In this year, for the first time we could verify Poisson statistics for the low quark modes in full dynamical QCD without any
Temperature dependence of the CP/sup N-1/ model and the analogy with quantum chromodynamics
International Nuclear Information System (INIS)
Actor, A.
1985-01-01
The two-dimensional CP/sup N-1/ model - a simple field-theoretic analogue of four-dimensional quantum chromodynamics (QCD) - is analysed and reviewed. The major themes are the temperature dependence of the CP/sup N-1/ model, and the analogy between CP/sup N-1/ and QCD. A detailed treatment of the 1/N approximation of the CP/sup N-1/ model is given. The main results emerging from this approximation are discussed at length. These are: asymptotic freedom, dimensional transmutation, confinement and topological charge nonquantization at zero temperature T = 0, screening and topological charge quantization at finite temperature T. The analogy with QCD is explained in detail. A new, qualitative, analysis of the CP/sup N-1/ model at finite temperature is introduced. This approach exploits the conformal invariance of the model to 'heat' an arbitrary CP/sup N-1/ field from T = 0 to finite temperature. This is achieved by conformal-transforming the flat Euclidean space-time of the T = 0 theory to the cylindrical space-time of the finite temperature theory. (author)
Topics in nuclear chromodynamics: Color transparency and hadronization in the nucleus
International Nuclear Information System (INIS)
Brodsky, S.J.
1988-03-01
The nucleus plays two complimentary roles in quantum chromodynamics: (1) A nuclear target can be used as a control medium or background field to modify or probe quark and gluon subprocesses. Some novel examples are color transparency, the predicted transparency of the nucleus to hadrons participating in high momentum transfer exclusive reactions, and formation zone phenomena, the absence of hard, collinear, target-induced radiation by a quark or gluon interacting in a high momentum transfer inclusive reaction if its energy is large compared to a scale proportional to the length of the target. (Soft radiation and elastic initial state interactions in the nucleus still occur.) Coalescence with co-moving spectators is discussed as a mechanism which can lead to increased open charm hadroproduction, but which also suppresses forward charmonium production (relative to lepton pairs) in heavy ion collisions. Also discussed are some novel features of nuclear diffractive amplitudes--high energy hadronic or electromagnetic reactions which leave the entire nucleus intact and give nonadditive contributions to the nuclear structure function at low /kappa cur//sub Bj/. (2) Conversely, the nucleus can be studied as a QCD structure. At short distances, nuclear wave functions and nuclear interactions necessarily involve hidden color, degrees of freedom orthogonal to the channels described by the usual nucleon or isobar degrees of freedom. At asymptotic momentum transfer, the deuteron form factor and distribution amplitude are rigorously calculable. One can also derive new types of testable scaling laws for exclusive nuclear amplitudes in terms of the reduced amplitude formalism
Chiral chains for lattice quantum chromodynamics at N/sub c/=infinity
International Nuclear Information System (INIS)
Brower, R.C.; Rossi, P.; Tan, C.
1981-01-01
We study chiral fields [U/sub i/ in the group U(N)] on a periodic lattice (U/sub i/=U/sub i/+L), with action S1/=(g-italic 2 )Σ/sup L//sub l/=1Tr(U/sub l/U/sup //sub l/+1+ U/sup //sub l/U/sub l/+1), as prototypes for lattice gauge theories [quantum chromodynamics (QCD)] at N/sub c/=infinity. Indeed, these chiral chains are equivalent to gauge theories on the surface of an L-faced polyhedron (e.g., L=4 is a tetrahedron, L=6 is the cube, and L=infinity is two-dimensional QCD). The one-link Schwinger-Dyson equation of Brower and Nauenberg, which gives the square of the transfer matrix, is solved exactly for all N. From the large-N solution, we solve exactly the finite chains for L=2, 3, 4, and infinity, on the weak-coupling side of the Gross-Witten singularity, which occurs at β=(g-italic 2 N) -1 =1/4, 1/3, π/8, and 1/2, respectively. We carry out weak and strong perturbation expansions at N/sub c/=infinity to estimate the singular part for all L, and to show confinement (as g 2 N→infinity) and asymptotic freedom (g 2 N→0) in the Migdal β function for QCD. The stability of the location of the Gross-Witten singularity for different-size lattices (L) suggests that QCD at N/sub c/=infinity enjoys this singularity in the transition region from strong to weak coupling
Hülsing, Tobias
Quantum chromodynamics, QCD, the theory of the strong interaction is split into two regimes. Scattering processes of the proton constituents, the partons, with a high momentum transfer $Q^2$ can be calculated and predicted with perturbative calculations. At low momentum transfers between the scattering particles perturbation theory is not applicable anymore, and phenomenological methods are used to describe the physics in this regime. The ATLAS experiment at the Large Hadron Collider, LHC, provides the possibility to analyze QCD processes at both ends of the momentum scale. Two measurements are presented in this thesis, emphasizing one of the two regimes each: The measurement of charged-particle event shape variables in inelastic proton–proton collisions at a center-of-mass energy of $\\sqrt{s}$ = 7 TeV analyses the transverse momentum flow and structure of hadronic events. Due to the, on average, low momentum transfer, predictions of these events are mainly driven by non-perturbative models. Three event sha...
Phenomenology of the proton and the nucleus through hard processes in quantum chromodynamics
International Nuclear Information System (INIS)
Gousset, T.
2005-01-01
My scientific domain is the phenomenology of the non-perturbative quantum chromodynamics (QCD). In the introduction I quickly present the history of QCD since its establishing in the seventies. The first chapter is dedicated to the achievements of the last decade concerning first the hard electroproduction at low impulse transfer in electron-proton reactions and secondly the search for the quark-gluon plasma in ultra-relativistic heavy ion reactions with the help of hard probes. In the second chapter I detail the hard electroproduction reactions with the aim of explaining their factorization in a sub-process including partons and whose amplitude can be computed in the theory of perturbations. Generalized parton distributions, that describe the transition from hadrons to partons could be useful to get more information on hadronic wave functions. Experimental implications are reviewed. The third chapter is dedicated to the J/ψ production in proton-nucleus collisions. J/ψ and the quarkonium family offer, thanks to their easy identification a useful tool to shed light on different sides of QCD such as the production of heavy quarks or the existence of the quark-gluon plasma. In the last chapter I present my last works that concern first the nuclear effects that appear in proton-nucleus collisions when we want to describe the relationship between the production cross-section of a particle and the value of the transverse momentum of the particle, and secondly the observation through radio-detection of big showers due to the interaction with the atmosphere of an ultra-high energy cosmic ray [fr
The application of light-cone quantization to quantum chromodynamics in one-plus-one dimensions
International Nuclear Information System (INIS)
Hornbostel, K.J.
1988-12-01
Formal and computational aspects of light cone quantization are studied by application to quantum chromodynamics (QCD) in one spatial plus one temporal dimension. This quantization scheme, which has been extensively applied to perturbative calculations, is shown to provide an intuitively appealing and numerically tractable approach to non-perturbative computations as well. In the initial section, a light-cone quantization procedure is developed which incorporates fields on the boundaries. This allows for the consistent treatment of massless fermions and the construction of explicitly conserved momentum and charge operators. The next section, which comprises the majority of this work, focuses on the numerical solution of the light-cone Schrodinger equation for bound states. The state space is constructed and the Hamiltonian is evaluated and diagonalized by computer for arbitrary number of colors, baryon number and coupling constant strength. As a result, the full spectrum of mesons and baryons and their associated wavefunctions are determined. These results are compared with those which exist from other approaches to test the reliability of the method. The program also provides a preliminary test for the feasibility of, and an opportunity to develop approximation schemes for, an attack on three-plus-one dimensional QCD. Finally, analytic results are presented which include a discussion of integral equations for wavefunctions and their endpoint behavior. Solutions for hadronic masses and wavefunctions in the limits of both large and small quark mass are discussed. 49 refs., 32 figs., 10 tabs
Stochastic methods for the fermion determinant in lattice quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Finkenrath, Jacob Friedrich
2015-02-17
In this thesis, algorithms in lattice quantum chromodynamics are presented by developing and using stochastic methods for fermion determinant ratios. For that an integral representation is proved which can be used also for non hermitian matrices. The stochastic estimation or the Monte Carlo integration of this integral representation introduces stochastic fluctuations which are controlled by using Domain Decomposition of the Dirac operator and introducing interpolation techniques. Determinant ratios of the lattice fermion operator, here the Wilson Dirac operator, are needed for corrections of the Boltzmann weight. These corrections have interesting applications e.g. in the mass by using mass reweighting. It will be shown that mass reweighting can be used e.g. to improve extrapolation in the light quark mass towards the chiral or physical point or to introduce an isospin breaking by splitting up the mass of the light quark. Furthermore the extraction of the light quark masses will be shown by using dynamical 2 flavor CLS ensembles. Stochastic estimation of determinant ratios can be used in Monte Carlo algorithms, e.g. in the Partial Stochastic Multi Step algorithm which can sample two mass-degenerate quarks. The idea is to propose a new configuration weighted by the pure gauge weight and including afterwards the fermion weight by using Metropolis accept-reject steps. It is shown by using an adequate interpolation with relative gauge fixing and a hierarchical filter structure that it is possible to simulate moderate lattices up to (2.1 fm){sup 4}. Furthermore the iteration of the pure gauge update can be increased which can decouple long autocorrelation times from the weighting with the fermions. Moreover a novel Hybrid Monte Carlo algorithm based on Domain Decomposition and combined with mass reweighting is presented. By using Domain Decomposition it is possible to split up the mass term in the Schur complement and the block operators. By introducing a higher mass
Study of the meson mass spectroscopy with a potential model inspired in the quantum chromodynamics
International Nuclear Information System (INIS)
Bernardini, Alex Eduardo de
2001-01-01
Since the discovery of QCD (Quantum Chromodynamics), there have been remarkable technical achievements in perturbative calculations applied to hadrons. However, it is difficult to use QCD directly to compute hadronic properties. In this context, phenomenological potential models have provided extremely satisfactory results on description of ordinary hadrons, more specifically about quark-antiquark bound states (mesons). In this work we propose and study the main aspects in the construction of a potential model and search a generalized description of meson spectroscopy, with emphasis in heavy quark bound states. We analyze important aspects in the choice of the treatment in good agreement with the dynamics of interacting particles, attempting to relativistic aspects as well as to the possibilities of nonrelativistic approximation analysis. Initially the 'soft QCD' is employed to determine effective potential terms establishing the asymptotic Coulomb term from one gluon exchange approximation. At the same time, a linear confinement term is introduced in accordance with QCD and phenomenological prescription. We perform the calculations of mass spectroscopy for particular sets of mesons and we verify whether the potential model could be extended to calculating the electronic transition rate (Γ(q q-bar → e - e + )). Finishing, we discuss the real physical possibilities of development of a generalized potential model (all quark flavors), its possible advantages relative to experimental parametrization, complexity in numerical calculations and in the description of physical reality in agreement with a quantum field theory (QCD). (author)
Energy Technology Data Exchange (ETDEWEB)
Perez Ramos, R
2006-09-15
We exactly calculate the double and simple inclusive transverse momentum (kt) distributions and the 2-particle momentum correlations inside high energy hadronic jets at the Modified Leading Logarithmic Approximation (MLLA) of Quantum Chromodynamics. We first obtain the exact solution of the evolution equations at 'small x', which we calculate at the so called 'limiting spectrum'. We then generalize this approximation by performing the steepest descent evaluation. Our predictions are in good agreement with data from Tevatron and improve those which have been obtained in the past. The comparison with forthcoming data (Tevatron, LHC) will further test the hypothesis of Local Hadron Parton Duality, and the eventual need to incorporate next-MLLA corrections. (authors)
Measurement of the lepton τ spectral functions and applications to quantum chromodynamic
International Nuclear Information System (INIS)
Hoecker, A.
1997-01-01
This thesis presents measurements of the τ vector (V) and axial-vector (A) hadronic spectral functions and phenomenological studies in the framework of quantum chromodynamics (QCD). Using the hypothesis of conserved vector currents (CVC), the dominant two- and four-pion vector spectral functions are compared to the corresponding cross sections from e + e - annihilation. A combined fit of the pion form factor from τ decays and e + e - data is performed using different parametrizations. The mass and the width of the ρ ± (770) and the ρ 0 (770) are separately determined in order to extract possible isospin violating effects. The mass and width differences are measured to be M ρ ± (770) - M ρ 0 (770) =(0.0±1.0) MeV/c 2 and Γ ρ ± (770) - Γ ρ 0 (770) =(0.1 ± 1.9) MeV/c 2 . Several QCD chiral sum rules involving the difference (V - A) of the spectral functions are compared to their measurements. The Borel-transformed Das-Mathur-Okubo sum rule is used to measure the pion polarizability to be α E =(2.68±0.91) x 10 -4 fm 3 . The τ vector and axial-vector hadronic widths and certain spectral moments are exploited to measure α s and non-perturbative contributions at the τ mass scale. The best, and experimentally and theoretically most robust, determination of α s (M τ ) is obtained from the inclusive (V + A) fit that yields α s (M τ )= 0.348±0.017 giving α s (M Z )=0.1211 ± 0.0021 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 τ hadronic width to masses smaller that the τ mass. Using the difference (V - A) of the spectral functions allows one to directly measure the dominant non-perturbative OPE dimension to be D=6.9±0.5. The vector spectral functions are used to improve the precision of the experimental determination of the hadronic contribution to the anomalous magnetic moment of the muon a μ =(g - 2)/2 and to the running of the QED
International Nuclear Information System (INIS)
Ellis, J.
1978-05-01
A review is given of reliable quantum chromodynamics predictions which either have or soon can be verified by experiment. Included are a discussion of the classic application of quantum chromodynamics perturbation theory and asymptotic freedom to predict scaling violations in deep inelastic leptoproduction experiments, with emphasis on the first direct experimental confirmation of the numerical values of the anomalous dimensions; a review of recent advances in developing and justifying quantum chromodynamics perturbation theory predictions for a number of physical applications not underwritten by the operator product expansion and renormalization group arguments; and mention of attempts to consider the reliability of quantum chromodynamics perturbation theory predictions, given the fact that nonperturbative effects are presumably crucial in quantum chromodynamics. 100 references
Martinelli, Guido
1994-01-01
1, Hadrons as bound states of quarks and gluons. 2, Quark models, confinement and asymptotic freedom. 3, The parton model; Deep Inelastic Scattering (DIS) process. 4, The parton model and QCD. 5) Phenomenology of the parton model; muon and neutrino DIS, structure functions and parton distributions. 6) W and Z production at Colliders. 7) Weak decays and strong interactions. 8) Heavy flavours effective theories and QCD. 9) Non-perturbative QCD.
International Nuclear Information System (INIS)
Brodsky, S.J.
1983-11-01
A number of novel features of QCD are reviewed, including the consequences of formation zone and color transparency phenomena in hadronic collisions, the use of automatic scale setting for perturbative predictions, null-zone phenomena as a fundamental test of gauge theory, and the relationship of intrinsic heavy colored particle Fock state components to new particle production. We conclude with a review of the applications of QCD to nuclear multiquark systems. 74 references
International Nuclear Information System (INIS)
Mosher, A.
1980-01-01
The symposium included lectures covering both the elements and the experimental tests of the theory of quantum chromdynamics. A three day topical conference was included which included the first results from PETRA as well as the latest reports from CERN, Fermilab, and SPEAR experiments. Twenty-one items from the symposium were prepared separately for the data base
Leutwyler, Heinrich
1995-01-01
1: Hadrons as bound states of quarks.Flavour and colour. 2: Gauge fields and the forces they generate. 3: Perturbation theory,asymptotic freedom,stength of the strong interaction. 4: Lattice formulation,confinement,flavour symmetries,anomalies. 5: Spontaneous symmetry breakdown,quark masses.
Energy Technology Data Exchange (ETDEWEB)
Marquet, C
2006-09-15
When probing small distances inside a hadron, one can resolve its partonic constituents: quarks and gluons that obey the laws of perturbative Quantum Chromodynamics (QCD). This substructure reveals itself in hadronic collisions characterized by a large momentum transfer: in such collisions, a hadron acts like a collection of partons whose interactions can be described in QCD. In a collision at moderate energy, a hadron looks dilute and the partons interact incoherently. As the collision energy increases, the parton density inside the hadron grows. Eventually, at some energy much bigger than the momentum transfer, one enters the saturation regime of QCD: the gluon density has become so large that collective effects are important. We introduce a formalism suitable to study hadronic collisions in the high-energy limit in QCD, and the transition to the saturation regime. In this framework, we derive known results that are needed to present our personal contributions and we compute different cross-sections in the context of hard diffraction and particle production. We study the transition to the saturation regime as given by the Balitsky-Kovchegov equation. In particular we derive properties of its solutions.We apply our results to deep inelastic scattering and show that, in the energy range of the HERA collider, the predictions of high-energy QCD are in good agreement with the data. We also consider jet production in hadronic collisions and discuss the possibility to test saturation at the Large Hadron Collider. (author)
Lattice Quantum Chromodynamics
Sachrajda, C T
2016-01-01
I review the the application of the lattice formulation of QCD and large-scale numerical simulations to the evaluation of non-perturbative hadronic effects in Standard Model Phenomenology. I present an introduction to the elements of the calculations and discuss the limitations both in the range of quantities which can be studied and in the precision of the results. I focus particularly on the extraction of the QCD parameters, i.e. the quark masses and the strong coupling constant, and on important quantities in flavour physics. Lattice QCD is playing a central role in quantifying the hadronic effects necessary for the development of precision flavour physics and its use in exploring the limits of the Standard Model and in searches for inconsistencies which would signal the presence of new physics.
Lattice quantum chromodynamics
International Nuclear Information System (INIS)
Hassenfratz, P.
1983-01-01
It is generally accepted that relativistic field theory is relevant in high energy physics. It is also recognized that even in QCD, which is asymptotically free, the scope of perturbation theory is very limited. Despite the tremendous theoretical and experimental effort to study scaling, scaling violations, e + e - , lepton pair creation, jets, etc., the answer to the question whether and to what extent is QCD the theory of strong interactions is vague. At present-day energies it is difficult to disentangle perturbative and non-perturbative effects. The author states that QCD must be understood and that quantitative non-perturbative methods are needed. He states that the lattice formulation of field theories is a promising approach to meeting this need and discusses the formulation in detail in this paper
Perturbative quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1979-12-01
The application of QCD to hadron dynamics at short distances, where asymptotic freedom allows a systematic perturbative approach, is addressed. The main theme of the approach is to incorporate systematically the effects of the hadronic wave function in large momentum transfer exclusive and inclusive reactions. Although it is conventional to treat the hadron as a classical source of on-shell quarks, there are important dynamical effects due to hadronic constituent structure which lead to a broader testing ground for QCD. QCD predictions are discussed for exclusive processes and form factors at large momentum transfer in which the short-distance behavior and the finite compositeness of the hadronic wave functions play crucial roles. Many of the standard tests of QCD are reviewed including the predictions for R = sigma/sub e + e - →had//sigma/sub e + e - →μ + μ - /, the structure functions of hadrons and photons, jet phenomena, and the QCD corrections to deep inelastic processes. The exclusive-inclusive connection in QCD, the effects of power-law scale-breaking contributions, and the important role of the available energy in controlling logarithmic scale violations are also discussed. 150 references, 44 figures
Testing quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1982-09-01
The difficulties in isolating specific QCD mechanisms which control hadronic phenomena, and the complications in obtaining quantitative tests of QCD are discussed. A number of novel QCD effects are reviewed, including heavy quark and higher twist phenomena, initial and final state interactions, direct processes, multiparticle collisions, color filtering, and nuclear target effects. The importance of understanding hadron production at the amplitude level is stressed
Using field theory in hadron physics
International Nuclear Information System (INIS)
Abarbanel, H.D.I.
1978-03-01
Topics are covered on the connection of field theory and hadron physics. The renormalization group and infrared and ultraviolet limits of field theory, in particular quantum chromodynamics, spontaneous mass generation, color confinement, instantons, and the vacuum state in quantum chromodynamics are treated. 21 references
Expectations for ultra-high energy interactions
International Nuclear Information System (INIS)
Feynman, R.P.
1978-01-01
Strong interactions at ultra-high energies are discussed with emphasis on the hadrons produced in high energy collisions. Evidence is considered that quantum chromodynamics might be the right theory, and also some estimates are given of quantum chromodynamics asymptotic-freedom phenomena, the work under discussion being very preliminary. 6 references
Quantum Chromodynamics (abstract only)
Hooft, G. 't
2000-01-01
The strong interactions were the last of the fundamental forces in the twentieth century to be fully understood in terms of basic and fundamental equations. Shortly after the discovery of the renormalizable non-Abelian gauge theories that unified the electroweak forces, it was realized that the
Beyond standard quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1995-09-01
Despite the many empirical successes of QCD, there are a number of intriguing experimental anomalies that have been observed in heavy flavor hadroproduction, in measurements of azimuthal correlations in deep inelastic processes, and in measurements of spin correlations in hadronic reactions. Such phenomena point to color coherence and multiparton correlations in the hadron wavefunctions and physics beyond standard leading twist factorization. Two new high precision tests of QCD and the Standard Model are discussed: classical polarized photoabsorption sum rules, which are sensitive to anomalous couplings and composite structure, and commensurate scale relations, which relate physical observables to each other without scale or scheme ambiguity. The relationship of anomalous couplings to composite structure is also discussed
Signatures for axial chromodynamics
International Nuclear Information System (INIS)
Pati, J.C.
1978-07-01
Within the context of basic left-right symmetry and the hypothesis of unification of weak, electromagnetic and strong forces at a mass level approximately equal to 10 4 -10 6 GeV, relatively light ''mass'' axial gluons, confined or liberated, must be postulated. The authors remark that the existence of such ''light'' axial gluons supplementing the familiar vector octet preserves the successes of QCD, both for deep inelastic processes and charmonium physics. Through the characteristic spin-spin force, generated by their exchange, they may even help resolve some of the discrepancies between vector QCD predictions and charmonium physics. The main remark of this note is that if colour is liberated, not only vector but also axial-vector gluons are produced in high-energy e - e + experiments, e.g. at PETRA and PEP, with fairly large cross-section. Distinctive decay modes of such liberated axial gluons are noted
Poincaré invariance in low-energy EFTs for QCD
Directory of Open Access Journals (Sweden)
Hwang Sungmin
2017-01-01
Full Text Available We present the calculations on deriving constraints between the Wilson coefficients in non-relativistic quantum chromodynamics and potential non-relativistic quantum chromodynamics by exploiting the symmetry of its fundamental theory, Poincaré invariance in particular. Implications of the constraints are briefly discussed in the context of the effective string theory.
Energy Technology Data Exchange (ETDEWEB)
Bernardini, Alex Eduardo de
2001-07-01
Since the discovery of QCD (Quantum Chromodynamics), there have been remarkable technical achievements in perturbative calculations applied to hadrons. However, it is difficult to use QCD directly to compute hadronic properties. In this context, phenomenological potential models have provided extremely satisfactory results on description of ordinary hadrons, more specifically about quark-antiquark bound states (mesons). In this work we propose and study the main aspects in the construction of a potential model and search a generalized description of meson spectroscopy, with emphasis in heavy quark bound states. We analyze important aspects in the choice of the treatment in good agreement with the dynamics of interacting particles, attempting to relativistic aspects as well as to the possibilities of nonrelativistic approximation analysis. Initially the 'soft QCD' is employed to determine effective potential terms establishing the asymptotic Coulomb term from one gluon exchange approximation. At the same time, a linear confinement term is introduced in accordance with QCD and phenomenological prescription. We perform the calculations of mass spectroscopy for particular sets of mesons and we verify whether the potential model could be extended to calculating the electronic transition rate ({gamma}(q q-bar {yields} e{sup -}e{sup +})). Finishing, we discuss the real physical possibilities of development of a generalized potential model (all quark flavors), its possible advantages relative to experimental parametrization, complexity in numerical calculations and in the description of physical reality in agreement with a quantum field theory (QCD). (author)
Energy Technology Data Exchange (ETDEWEB)
Bernardini, Alex Eduardo de
2001-07-01
Since the discovery of QCD (Quantum Chromodynamics), there have been remarkable technical achievements in perturbative calculations applied to hadrons. However, it is difficult to use QCD directly to compute hadronic properties. In this context, phenomenological potential models have provided extremely satisfactory results on description of ordinary hadrons, more specifically about quark-antiquark bound states (mesons). In this work we propose and study the main aspects in the construction of a potential model and search a generalized description of meson spectroscopy, with emphasis in heavy quark bound states. We analyze important aspects in the choice of the treatment in good agreement with the dynamics of interacting particles, attempting to relativistic aspects as well as to the possibilities of nonrelativistic approximation analysis. Initially the 'soft QCD' is employed to determine effective potential terms establishing the asymptotic Coulomb term from one gluon exchange approximation. At the same time, a linear confinement term is introduced in accordance with QCD and phenomenological prescription. We perform the calculations of mass spectroscopy for particular sets of mesons and we verify whether the potential model could be extended to calculating the electronic transition rate ({gamma}(q q-bar {yields} e{sup -}e{sup +})). Finishing, we discuss the real physical possibilities of development of a generalized potential model (all quark flavors), its possible advantages relative to experimental parametrization, complexity in numerical calculations and in the description of physical reality in agreement with a quantum field theory (QCD). (author)
The origin of mass and experiments on high-energy particle accelerators
International Nuclear Information System (INIS)
Ioffe, B.L.
2006-01-01
The visible world is one consisting of nucleons and electrons. The mass of nucleon arises from chiral symmetry breaking in quantum chromodynamics, so high energy accelerator experiments cannot give a clue to the nature of mass of matter in the visible world. The origin of the mass of the matter will be clarified when the mechanism of chiral symmetry breaking in quantum chromodynamics is established [ru
Using field theory in hadron physics
International Nuclear Information System (INIS)
Abarbanel, H.D.I.
1979-01-01
The author gives an introductory review about the development of applications of quantum field theory in hadron physics. Especially he discusses the renormalization group and the use of this group for the selection of a field theory. In this framework he compares quantum chromodynamics with quantum electrodynamics. Finally he discusses dynamic mass generation and quark confinement in the framework of quantum chromodynamics. (HSI) [de
Quantum Simulation of the Hubbard Model Using Ultra-Cold Atoms
2008-11-01
Hubbard model. The SU(3) Hubbard model has been proposed as a model system for studying different phases of matter expected to occur in quantum...chromodynamics (QCD): the color superconducting phase and the formation of baryons . Our initial investigations have focused on understanding three-body...density quark matter described by quantum chromodynamics . We have been investigating the stability of the 3-state Fermi gas with respect to decay due
Polarization phenomena in quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Brodsky, S.J. [Stanford Univ., CA (United States)
1994-12-01
The author discusses a number of interrelated hadronic spin effects which test fundamental features of perturbative and nonperturbative QCD. For example, the anomalous magnetic moment of the proton and the axial coupling g{sub A} on the nucleon are shown to be related to each other for fixed proton radius, independent of the form of the underlying three-quark relativistic quark wavefunction. The renormalization scale and scheme ambiguities for the radiative corrections to the Bjorken sum rule for the polarized structure functions can be eliminated by using commensurate scale relations with other observables. Other examples include (a) new constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton at large and small x{sub bj}; (b) consequences of the principle of hadron retention in high x{sub F} inclusive reactions; (c) applications of hadron helicity conservation to high momentum transfer exclusive reactions; and (d) the dependence of nuclear structure functions and shadowing on virtual photon polarization. The author also discusses the implications of a number of measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A{sub NN} observed in large angle proton-proton scattering, the anomalously large {rho}{pi} branching ratio of the J/{psi}, and the rapidly changing polarization dependence of both J/{psi} and continuum lepton pair hadroproduction observed at large x{sub F}. The azimuthal angular dependence of the Drell-Yan process is shown to be highly sensitive to the projectile distribution amplitude, the fundamental valence light-cone wavefunction of the hadron.
Exclusive processes in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.; Lepage, G.P.
1981-06-01
Large momentum transfer exclusive processes and the short distance structure of hadronic wave functions can be systematically analyzed within the context of perturbative QCD. Predictions for meson form factors, two-photon processes γγ → M anti M, hadronic decays of heavy quark systems, and a number of other related QCD phenomena are reviewed
Novel features of nuclear chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J. [Stanford University, SLAC National Accelerator Laboratory, Stanford, CA (United States)
2017-03-15
I review a number of QCD topics where the nuclear environment provides new insights into fundamental aspects of the strong interactions. The topics include novel perspectives for nuclear physics, such as the hidden color of nuclear form factors, the relation of the nuclear force at short distances to quark interchange interactions, the effects of ''color transparency'' on the baryon-to-meson anomaly in hard heavy-ion collisions, flavor-dependent antishadowing, novel exotic multiquark states, the anomalous nuclear dependence of quarkonium hadroproduction, flavor-dependent antishadowing, and the breakdown of sum rules for nuclear structure functions. I also briefly discuss the insights into hadron physics and color confinement that one obtains from light-front holography, including supersymmetric features of the hadron spectrum. I also note that the virtual Compton amplitude on a proton (or nucleus) can be measured for two spacelike photons q{sup 2}{sub 1}, q{sup 2}{sub 2} < 0 using positronium-proton scattering [e{sup +}e{sup -}]p → e{sup +}e{sup -}p{sup '}. (orig.)
Working group report: Quantum chromodynamics
Indian Academy of Sciences (India)
3NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam, The Netherlands. 4Harish-Chandra Research Institute, Chhatnag Road, Jhusi, Allahabad 211 ... tant to extend the resummation framework to polarised process to look at polarised.
Working Group Report: Quantum Chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Campbell, J. M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
2013-10-18
This is the summary report of the energy frontier QCD working group prepared for Snowmass 2013. We review the status of tools, both theoretical and experimental, for understanding the strong interactions at colliders. We attempt to prioritize important directions that future developments should take. Most of the efforts of the QCD working group concentrate on proton-proton colliders, at 14 TeV as planned for the next run of the LHC, and for 33 and 100 TeV, possible energies of the colliders that will be necessary to carry on the physics program started at 14 TeV. We also examine QCD predictions and measurements at lepton-lepton and lepton-hadron colliders, and in particular their ability to improve our knowledge of strong coupling constant and parton distribution functions.
Glueball masses in quantum chromodynamics
International Nuclear Information System (INIS)
Luo Xiangqian; Zhongshan Univ., Guangzhou, GD; Zhongshan Univ., Guangzhou; Chen Qizhou; Zhongshan Univ., Guangzhou, GD; Zhongshan Univ., Guangzhou; Guo Shuohong; Zhongshan Univ., Guangzhou, GD; Zhongshan Univ., Guangzhou; Fang Xiyan; Zhongshan Univ., Guangzhou, GD; Zhongshan Univ., Guangzhou; Liu Jinming; Zhongshan Univ., Guangzhou, GD; Zhongshan Univ., Guangzhou
1996-01-01
We review the recent glueball mass calculations using an efficient method for solving the Schroedinger equation order by order with a scheme preserving the continuum limit. The reliability of the method is further supported by new accurate results for (1+1)-dimensional σ models and (2+1)-dimensional non-abelian models. We present first and encouraging data for the glueball masses in 3+1 dimensional QCD. (orig.)
Quantum chromodynamics at large distances
International Nuclear Information System (INIS)
Arbuzov, B.A.
1987-01-01
Properties of QCD at large distances are considered in the framework of traditional quantum field theory. An investigation of asymptotic behaviour of lower Green functions in QCD is the starting point of the approach. The recent works are reviewed which confirm the singular infrared behaviour of gluon propagator M 2 /(k 2 ) 2 at least under some gauge conditions. A special covariant gauge comes out to be the most suitable for description of infrared region due to absence of ghost contributions to infrared asymptotics of Green functions. Solutions of Schwinger-Dyson equation for quark propagator are obtained in this special gauge and are shown to possess desirable properties: spontaneous breaking of chiral invariance and nonperturbative character. The infrared asymptotics of lower Green functions are used for calculation of vacuum expectation values of gluon and quark fields. These vacuum expectation values are obtained in a good agreement with the corresponding phenomenological values which are needed in the method of sum rules in QCD, that confirms adequacy of the infrared region description. The consideration of a behaviour of QCD at large distances leads to the conclusion that at contemporary stage of theory development one may consider two possibilities. The first one is the well-known confinement hypothesis and the second one is called incomplete confinement and stipulates for open color to be observable. Possible manifestations of incomplete confinement are discussed
Polarization phenomena in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1994-03-01
The author discusses a number of interrelated hadronic spin effects which test fundamental features of perturbative and non-perturbative QCD. For example, the anomalous magnetic moment of the proton and the axial coupling g A on the nucleon are shown to be related to each other for fixed proton radius, independent of the form of the underlying three-quark relativistic quark wavefunction. The renormalization scale and scheme ambiguities for the radiative corrections to the Bjorken sum rule for the polarized structure functions can be eliminated by using commensurate scale relations with other observables. Other examples include (a) new constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton at large and small x bj ; (b) consequences of the principle of hadron helicity retention in high x F inclusive reactions; (c) applications of hadron helicity conservation to high momentum transfer exclusive reactions; and (d) the dependence of nuclear structure functions and shadowing on virtual photon polarization. He also discusses the implications of a number of measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A NN observed in large angle proton-proton scattering, the anomalously large ρπ branching ratio of the J/ψ, and the rapidly changing polarization dependence of both J/ψ and continuum lepton pair hadroproduction observed at large x F . The azimuthal angular dependence of the Drell-Yan process is shown to be highly sensitive to the projectile distribution amplitude, the fundamental valence light-cone wavefunction of the hadron
Quantum chromodynamics at hadron colliders
Indian Academy of Sciences (India)
From a theoretical point of view, it is a gauge field theory featuring asymptotic ... pQCD tenets are the universality of the infrared (IR) behaviour, the cancellation of ... investigation is being planned also through the Drell–Yan production of vector.
Testing quantum chromodynamics in electroproduction
International Nuclear Information System (INIS)
Brodsky, S.J.
1987-05-01
The exclusive channels in electroproduction are discussed. The study of color transparency, the formation zone, and other novel aspects of QCD by measuring exclusive reactions inside nuclear targets is covered. Diffractive electroproduction channels are discussed, and exclusive nuclear processes in QCD are examined. Non-additivity of nuclear structure functions (EMC effect) is also discussed, as well as jet coalescence in electroproduction
New results in quantum chromodynamics
International Nuclear Information System (INIS)
Gustafson, Goesta.
1990-01-01
Recent developments in QCD are discussed in particular how the dipole formalism and a recently proposed multiplicity measure can be used as efficient tools to study the properties of the QCD shower evolution. The focus is on applications to e + e - -annihilation into hadrons
Lattice Methods for Quantum Chromodynamics
DeGrand, Thomas
2006-01-01
Numerical simulation of lattice-regulated QCD has become an important source of information about strong interactions. In the last few years there has been an explosion of techniques for performing ever more accurate studies on the properties of strongly interacting particles. Lattice predictions directly impact many areas of particle and nuclear physics theory and phenomenology. This book provides a thorough introduction to the specialized techniques needed to carry out numerical simulations of QCD: a description of lattice discretizations of fermions and gauge fields, methods for actually do
Quantum chromodynamics at high energy
Kovchegov, Yuri V
2012-01-01
Filling a gap in the current literature, this book is the first entirely dedicated to high energy QCD including parton saturation. It presents groundbreaking progress on the subject and describes many of the problems at the forefront of research, bringing postgraduate students, theorists and advanced experimentalists up to date with the current status of the field. A broad range of topics in high energy QCD are covered, most notably on the physics of parton saturation and the Color Glass Condensate (CGC). The material is presented in a pedagogical way, with numerous examples and exercises. Discussion ranges from the quasi-classical McLerran–Venugopalan model to the linear and non-linear BFKL/BK/JIMWLK small-x evolution equations. The authors adopt both a theoretical and experimental outlook and present the physics of strong interactions in a universal way, making it useful to physicists from various sub-communities and applicable to processes studied at high energy accelerators around the world.
Lattice quantum chromodynamics: Some topics
Indian Academy of Sciences (India)
I will begin with a lightning quick overview of the basic lattice gauge theory and then go on to .... The Monte Carlo technique to evaluate C(t), or the expectation value of any other observable ... x }occurs with a probability proportional to. 890.
Working group report: Quantum chromodynamics
Indian Academy of Sciences (India)
variance, mass factorisation and Sudakov resummation of QCD amplitudes as the guiding principles. ... The symbol 'C' means convolution. Here we .... As colliders cross new energy and luminosity frontiers, there will be opportunity to test the ...
Testing Quantum Chromodynamics with Antiprotons
Energy Technology Data Exchange (ETDEWEB)
Brodsky, S.
2004-10-21
The antiproton storage ring HESR to be constructed at GSI will open up a new range of perturbative and nonperturbative tests of QCD in exclusive and inclusive reactions. I discuss 21 tests of QCD using antiproton beams which can illuminate novel features of QCD. The proposed experiments include the formation of exotic hadrons, measurements of timelike generalized parton distributions, the production of charm at threshold, transversity measurements in Drell-Yan reactions, and searches for single-spin asymmetries. The interactions of antiprotons in nuclear targets will allow tests of exotic nuclear phenomena such as color transparency, hidden color, reduced nuclear amplitudes, and the non-universality of nuclear antishadowing. The central tool used in these lectures are light-front Fock state wavefunctions which encode the bound-state properties of hadrons in terms of their quark and gluon degrees of freedom at the amplitude level. The freedom to choose the light-like quantization four-vector provides an explicitly covariant formulation of light-front quantization and can be used to determine the analytic structure of light-front wave functions. QCD becomes scale free and conformally symmetric in the analytic limit of zero quark mass and zero {beta} function. This ''conformal correspondence principle'' determines the form of the expansion polynomials for distribution amplitudes and the behavior of non-perturbative wavefunctions which control hard exclusive processes at leading twist. The conformal template also can be used to derive commensurate scale relations which connect observables in QCD without scale or scheme ambiguity. The AdS/CFT correspondence of large N{sub C} supergravity theory in higher-dimensional anti-de Sitter space with supersymmetric QCD in 4-dimensional space-time has important implications for hadron phenomenology in the conformal limit, including the nonperturbative derivation of counting rules for exclusive processes and the behavior of structure functions at large x{sub bj}. String/gauge duality also predicts the QCD power-law fall-off of light-front Fock-state hadronic wavefunctions with arbitrary orbital angular momentum at high momentum transfer. I also review recent work which shows that the diffractive component of deep inelastic scattering, single spin asymmetries, as well as nuclear shadowing and antishadowing, cannot be computed from the LFWFs of hadrons in isolation.
Two topics in quantum chromodynamics
International Nuclear Information System (INIS)
Bjorken, J.D.
1989-12-01
The two topics are (1) estimates of perturbation theory coefficients for R(e + e - → hadrons), and (2) the virtual-photon structure function, with emphasis on the analytic behavior in its squared mass. 20 refs., 4 figs., 2 tabs
QCD development in the early universe
Energy Technology Data Exchange (ETDEWEB)
Gromov, N. A., E-mail: gromov@dm.komisc.ru [Komi Science Center of the Ural Division of the Russian Academy of Sciences, Department of Mathematics (Russian Federation)
2017-03-15
The high-energy limit of Quantum Chromodynamics is generated by the contraction of its gauge groups. Contraction parameters are taken identical with those of the Electroweak Model and tend to zero when energy increases. At the infinite energy limit all quarks lose masses and have only one color degree of freedom. The limit model represents the development of Quantum Chromodynamics in the early Universe from the Big Bang up to the end of several milliseconds.
7th CERN - Latin-American School of High-Energy Physics
Mulders, M; CLASHEP 2013; CLASHEP2013
2015-01-01
The CERN–Latin-American School of High-Energy Physics is intended to give young physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lecture notes on the Standard Model of electroweak interactions, quantum chromodynamics, flavour physics, quantum chromodynamics under extreme conditions, cosmic-ray physics, cosmology, recent highlights of LHC results, practical statistics for particle physicists and a short introduction to the principles of particle physics instrumentation.
International Nuclear Information System (INIS)
Preparata, G.
1983-01-01
In this paper the necessity of going beyond Quantum chromodynamics is argued, and a new theory of Isotropic Chromodynamics (ICD) is introduced. The basic theoretical notions behind QCD--quarks, colors, and gauge theory are retained, but the conclusion that QCD must be the theory of hadrions is questioned. Two points of QCD are reviewed, gluons (including glueballs), and asymptotic freedom. It is suggested that much of this theory is wishful thinking. Beyond QCD, aspects which are puzzling in hadrodynamics are well understood in two-dimensional gauge theories (confinement, freedom at short distances etc). Anisotropic chromodynamics is proposed in the attempt to conjugate the basic pillars of hadrodynamics with the peculiar characteristics of two-dimensional gauge dynamics. In order to construct a gauge dynamics for the color field which is isomorphic to a two-dimensional gauge-theory base space must be enlarged to a seven dimension space-time structure, to be called Anisotropic Space-Time (AST). The ideas and present achievements of ICD are then reviewed
Case studies in perturbative quantum chromodynamics
International Nuclear Information System (INIS)
Berger, E.L.
1979-09-01
A few aspects of QCD are discussed, beginning with a discussion of the ingredients of QCD and their observational basis. A pedagogical treatment of scaling violations is presented and the argument is presented that while entirely consistent with QCD, the phenomenological situation is clouded by the potentially crucial role of higher twist effects in the theory. Some explicit calculations of higher twist effects are presented
Quantum chromodynamics studies at LEP2
Indian Academy of Sciences (India)
swaban swaban
Studies of the annihilation process at LEP2 have given rise to results on jet rate, event ..... The electroweak theory explain the data at all these energies. .... like (a) smooth suppression of hadron-like and point-like 7 interaction, (b) dual parton.
Quantum chromodynamics as dynamics of loops
International Nuclear Information System (INIS)
Makeenko, Yu.M.; Migdal, A.A.
1981-01-01
QCD is entirely reformulated in terms of white composite fields - the traces of the loop products. The 1/N expansion turns out to be the WKB (Hartree-Fock) approximation for these fields. The 'classical' equation describing the N = infinite case is reduced tp a bootstrap form. New, manifestly gauge-invariant perturbation theory in the loop space, reproducing asymptotic freedom, is developed by iterations of this equation. The area law appears to be a self-consistent solution at large loops. (orig.)
Heavy quark production in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1986-09-01
For very heavy quark masses, the inclusive hadronic production of hadron pairs containing heavy quarks is predicted to be governed by QCD fusion subprocesses. For intermediate mass scales other QCD mechanisms can be important including higher-twist intrinsic contributions and low relative velocity enchancements, possibly accounting for the anomalies observed in charm hadroproduction, such as the nuclear number dependence, the longitudinal momentum distributions, and beam flavor dependence. We also discuss scaling laws for exclusive processes involving heavy quarks and diffractive excitation into heavy quark systems
Dynamical fermions in lattice quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Szabo, Kalman
2007-07-01
The thesis presentS results in Quantum Chromo Dynamics (QCD) with dynamical lattice fermions. The topological susceptibilty in QCD is determined, the calculations are carried out with dynamical overlap fermions. The most important properties of the quark-gluon plasma phase of QCD are studied, for which dynamical staggered fermions are used. (orig.)
Dynamical fermions in lattice quantum chromodynamics
International Nuclear Information System (INIS)
Szabo, Kalman
2007-01-01
The thesis presentS results in Quantum Chromo Dynamics (QCD) with dynamical lattice fermions. The topological susceptibilty in QCD is determined, the calculations are carried out with dynamical overlap fermions. The most important properties of the quark-gluon plasma phase of QCD are studied, for which dynamical staggered fermions are used. (orig.)
Connections between quantum chromodynamics and condensed
Indian Academy of Sciences (India)
Using examples we discuss some of the connections between the two fields and show how progress can be made by exploiting this connection. Some of the challenges that remain in ... Current Issue : Vol. 90, Issue 6. Current Issue Volume 90 ...
Spin effects in perturbative quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.; Lepage, G.P.
1980-12-01
The spin dependence of large momentum transfer exclusive and inclusive reactions can be used to test the gluon spin and other basic elements of QCD. In particular, exclusive processes including hadronic decays of heavy quark resonances have the potential of isolating QCD hard scattering subprocesses in situations where the helicities of all the interacting constituents are controlled. The predictions can be summarized in terms of QCD spin selection rules. The calculation of magnetic moment and other hadronic properties in QCD are mentioned
High-density limit of quantum chromodynamics
International Nuclear Information System (INIS)
Alvarez, E.
1983-01-01
By means of a formal expansion of the partition function presumably valid at large baryon densities, the propagator of the quarks is expressed in terms of the gluon propagator. This result is interpreted as implying that correlations between quarks and gluons are unimportant at high enough density, so that a kind of mean-field approximation gives a very accurate description of the physical system
Heavy-quark physics in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1991-04-01
Heavy quarks can expose new symmetries and novel phenomena in QCD not apparent in ordinary hadronic systems. In these lectures I discuss the use of effective-Lagrangian and light-cone Fock methods to analyze exclusive heavy hadron decays such as Υ → p bar p and B → ππ, and also to derive effective Schroedinger and Dirac equations for heavy quark systems. Two contributions to the heavy quark structure functions of the proton and other light hadrons are identified: an ''extrinsic'' contribution associated with leading twist QCD evolution of the gluon distribution, and a higher twist ''intrinsic'' contribution due to the hardness of high-mass fluctuations of multi-gluon correlations in hadronic wavefunctions. A non-perturbative calculation of the heavy quark distribution of a meson in QCD in one space and one time is presented. The intrinsic higher twist contributions to the pion and proton structure functions can dominate the hadronic production of heavy quark systems at large longitudinal momentum fraction x F and give anomalous contributions to the quark structure functions of ordinary hadrons at large x bj . I also discuss a number of ways in which heavy quark production in nuclear targets can test fundamental QCD phenomena and provide constraints on hadronic wavefunctions. The topics include color transparency, finite formation time, and predictions for charm production at threshold, including nuclear-bound quarkonium. I also discuss a number of QCD mechanisms for the suppression of J/ψ and Υ production in nuclear collisions, including gluon shadowing, the peripheral excitation of intrinsic heavy quark components at large x F , and the coalescence of heavy quarks with co-moving spectators at low x F
On de-globalization in quantum chromodynamics
Indian Academy of Sciences (India)
classic Sterman-Weinberg jet definition to currently studied event shapes and rapidity gap observables. ... shapes, rapidity gap observables, jet fractions defined through cone-type algorithms, .... area of research in QCD. Reference. [1] We use ...
Light-cone quantization of quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.; Pauli, H.C.
1991-06-01
We discuss the light-cone quantization of gauge theories from two perspectives: as a calculational tool for representing hadrons as QCD bound-states of relativistic quarks and gluons, and also as a novel method for simulating quantum field theory on a computer. The light-cone Fock state expansion of wavefunctions at fixed light cone time provides a precise definition of the parton model and a general calculus for hadronic matrix elements. We present several new applications of light-cone Fock methods, including calculations of exclusive weak decays of heavy hadrons, and intrinsic heavy-quark contributions to structure functions. A general nonperturbative method for numerically solving quantum field theories, ''discretized light-cone quantization,'' is outlined and applied to several gauge theories, including QCD in one space and one time dimension, and quantum electrodynamics in physical space-time at large coupling strength. The DLCQ method is invariant under the large class of light-cone Lorentz transformations, and it can be formulated such at ultraviolet regularization is independent of the momentum space discretization. Both the bound-state spectrum and the corresponding relativistic light-cone wavefunctions can be obtained by matrix diagonalization and related techniques. We also discuss the construction of the light-cone Fock basis, the structure of the light-cone vacuum, and outline the renormalization techniques required for solving gauge theories within the light-cone Hamiltonian formalism
Light-cone quantization of quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Brodsky, S.J. (Stanford Linear Accelerator Center, Menlo Park, CA (USA)); Pauli, H.C. (Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany, F.R.))
1991-06-01
We discuss the light-cone quantization of gauge theories from two perspectives: as a calculational tool for representing hadrons as QCD bound-states of relativistic quarks and gluons, and also as a novel method for simulating quantum field theory on a computer. The light-cone Fock state expansion of wavefunctions at fixed light cone time provides a precise definition of the parton model and a general calculus for hadronic matrix elements. We present several new applications of light-cone Fock methods, including calculations of exclusive weak decays of heavy hadrons, and intrinsic heavy-quark contributions to structure functions. A general nonperturbative method for numerically solving quantum field theories, discretized light-cone quantization,'' is outlined and applied to several gauge theories, including QCD in one space and one time dimension, and quantum electrodynamics in physical space-time at large coupling strength. The DLCQ method is invariant under the large class of light-cone Lorentz transformations, and it can be formulated such at ultraviolet regularization is independent of the momentum space discretization. Both the bound-state spectrum and the corresponding relativistic light-cone wavefunctions can be obtained by matrix diagonalization and related techniques. We also discuss the construction of the light-cone Fock basis, the structure of the light-cone vacuum, and outline the renormalization techniques required for solving gauge theories within the light-cone Hamiltonian formalism.
Novel spin effects in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1993-02-01
This report discusses a number of interesting hadronic spin effects which test fundamental features of perturbative and non-perturbative QCD. These include constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton; the principle of hadron helicity retention in high x F inclusive reactions; predictions based on total hadron helicity conservation in high momentum transfer exclusive reactions; the dependence of nuclear structure functions and shadowing on virtual photon polarization; and general constraints on the magnetic moment of hadrons. I also will discuss the implications of several measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A NN observed in large angle proton-proton scattering, the anomalously large ρπ branching ratio of the J/ψ, and the rapidly changing polarization dependence of both J/ψ and continuum lepton pair hadroproduction observed at large x F
Quantum chromodynamics (QCD) and collider physics
International Nuclear Information System (INIS)
Ellis, R.K.; Stirling, W.J.
1990-01-01
This report discusses: fundamentals of perturbative QCD; QCD in e + e - → hadrons; deep inelastic scattering and parton distributions; the QCD parton model in hadron-hadron collisions; large p T jet production in hadron-hadron collisions; the production of vector bosons in hadronic collisions; and the production of heavy quarks
Scaling violations and perturbative quantum chromodynamics
International Nuclear Information System (INIS)
Barbieri, R.; d'Emilio, E.; Caneschi, L.; Curci, G.
1979-01-01
The authors try to understand the meaning of the recent data on scaling violations of the moments of the structure function F 3 measured in γ and anti γ deep inelastic scattering, and their relevance as a test of QCD. This is done by reducing to the minimum the theoretical machinery and prejudices and stressing the perturbative nature of the problem. This leads to a definition of the perturbation coupling constant αsub(s) (Q = 2.5 GeV) = 0.61 +- 0.06, in terms of which the corrective terms for all quantities computed so far turn out to be relatively small. (Auth.)
Quantum chromodynamics near the confinement limit
International Nuclear Information System (INIS)
Quigg, C.
1985-09-01
These nine lectures deal at an elementary level with the strong interaction between quarks and its implications for the structure of hadrons. Quarkonium systems are studied as a means for measuring the interquark interaction. This is presumably (part of) the answer a solution to QCD must yield, if it is indeed the correct theory of the strong interactions. Some elements of QCD are reviewed, and metaphors for QCD as a confining theory are introduced. The 1/N expansion is summarized as a way of guessing the consequences of QCD for hadron physics. Lattice gauge theory is developed as a means for going beyond perturbation theory in the solution of QCD. The correspondence between statistical mechanics, quantum mechanics, and field theory is made, and simple spin systems are formulated on the lattice. The lattice analog of local gauge invariance is developed, and analytic methods for solving lattice gauge theory are considered. The strong-coupling expansion indicates the existence of a confining phase, and the renormalization group provides a means for recovering the consequences of continuum field theory. Finally, Monte Carlo simulations of lattice theories give evidence for the phase structure of gauge theories, yield an estimate for the string tension characterizing the interquark force, and provide an approximate description of the quarkonium potential in encouraging good agreement with what is known from experiment
Pramana – Journal of Physics | Indian Academy of Sciences
Indian Academy of Sciences (India)
Keywords. Perturbative quantum chromodynamics; hard thermal loop; gluon condensate; quark–gluon plasma; dispersion relation; collective modes; van Hove singularity; relativistic heavy-ion collisions.
Energy Technology Data Exchange (ETDEWEB)
Hoecker, A [Paris-11 Univ., 91 - Orsay (France). Lab. de l' Accelerateur Lineaire; [Universite de Paris Sud, 91 - Orsay (France)
1997-04-18
This thesis presents measurements of the {tau} vector (V) and axial-vector (A) hadronic spectral functions and phenomenological studies in the framework of quantum chromodynamics (QCD). Using the hypothesis of conserved vector currents (CVC), the dominant two- and four-pion vector spectral functions are compared to the corresponding cross sections from e{sup +}e{sup -} annihilation. A combined fit of the pion form factor from {tau} decays and e{sup +}e{sup -} data is performed using different parametrizations. The mass and the width of the {rho}{sup {+-}}(770) and the {rho}{sup 0}(770) are separately determined in order to extract possible isospin violating effects. The mass and width differences are measured to be M{sub {rho}{sup {+-}}{sub (770)} - M{sub {rho}{sup 0}}{sub (770)}=(0.0{+-}1.0) MeV/c{sup 2} and {gamma}{sub {rho}{sup {+-}}{sub (770)} - {gamma}{sub {rho}{sup 0}}{sub (770)}=(0.1 {+-} 1.9) MeV/c{sup 2}. Several QCD chiral sum rules involving the difference (V - A) of the spectral functions are compared to their measurements. The Borel-transformed Das-Mathur-Okubo sum rule is used to measure the pion polarizability to be {alpha}{sub E}=(2.68{+-}0.91) x 10{sup -4} fm{sup 3}. The {tau} vector and axial-vector hadronic widths and certain spectral moments are exploited to measure {alpha}{sub s} and non-perturbative contributions at the {tau} mass scale. The best, and experimentally and theoretically most robust, determination of {alpha}{sub s}(M{sub {tau}}) is obtained from the inclusive (V + A) fit that yields {alpha}{sub s}(M{sub {tau}})= 0.348{+-}0.017 giving {alpha}{sub s}(M{sub Z})=0.1211 {+-} 0.0021 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 {tau} hadronic width to masses smaller that the {tau} mass. Using the difference (V - A) of the spectral functions allows one to directly measure the dominant non-perturbative OPE dimension to be D=6
Two-photon exclusive processes in quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Brodsky, S.J.
1986-07-01
QCD predictions for ..gamma gamma.. annihilation into single mesons, meson pairs, and baryon pairs are reviewed. Two-photon exclusive processes provide the most sensitive and practical measure of the distribution amplitudes, and thus a critical confrontation between QCD and experiment. Both the angular distribution and virtual photon mass dependence of these amplitudes are sensitive to the shapes of the phi (chi, Q). Novel effects involving the production of qq anti q anti q states at threshold are also discussed, and a new method is presented for systematically incorporating higher-order QCD corrections in ..gamma gamma.. reactions.
Large-Nc quantum chromodynamics and harmonic sums
Indian Academy of Sciences (India)
2012-06-08
Jun 8, 2012 ... This has led us to consider a class of analytic number theory .... The self-energy function LR(Q2) in the chiral limit vanishes order by order in QCD ... the 1/Nc expansion, the Goldstone loop corrections are subleading and, ...
Gauge field condensation in geometric quantum chromodynamics
International Nuclear Information System (INIS)
Guendelman, E.I.
1991-09-01
In odd number of dimensions, it is possible to construct general covariant gauge theories, where the metric is not an independent variable, but local function of the gauge fields. Starting from standardly defined gauge theory, upon functional integration of some variables, we could end up with such moodels. For models with SU(2) and SU(3) symmetry in three dimensions, gauge field condensation take place in the vacuum, which is nevertheless homogeneous and isotropic up to a gauge transformation, provided the space is flat. Introducing Higgs fields that spontaneously break the gauge symmetry, we get a breakdown of the homogenity and isotropy of the vacuum. Finally, we discuss how some of this ideas can be generalized to four and other even dimensions. (author)
Experimental studies of the quantum chromodynamics phase ...
Indian Academy of Sciences (India)
2015-05-06
BES) ... Experimental studies of the QCD phase diagram at the STAR experiment .... However, the observed difference between v2 of particles and antiparticles could .... The grey band at the right corresponds to systematic.
Phenomenology of heavy quarkonia and quantum chromodynamics
International Nuclear Information System (INIS)
Schmitz, S.J.A.
1986-01-01
Heavy quarkonia, the c anti c, b anti b, and soon to be discovered t anti t families of states, are studied in the framework of potential theory. The earlier proposed, flavor independent Riverside potential is fit to masses of c anti c and b anti b states and their electronic widths are calculated. An unusual feature of the potential is the use of a parameter b which controls the small r or asymptotic freedom behavior and which can be related to the QCD scale parameters Λ/MS. This parameter b is virtually undetermined by the c anti c and b anti b spectra, merely excluding the range b < 4 or Λ/MS ≤ 120 MeV and slightly favoring Λ/MS ≅ 250 MeV. It is shown how even minimal information on the t anti t states will restrict the Λ/MS value to a range of the order of 50 MeV. A recent Lattice Gauge potential shows a remarkable closeness to the phenomenological approach. In view of the approximations involved, the difference between the two potentials is small. This difference is investigated in terms of the strong coupling constant α which can be extracted from both potentials. In the main r regime the Lattice Gauge α is markedly smaller than the phenomenological one. It is shown that the absence of intermediate, virtual quark loops in the Lattice Gauge calculation, i.e. the so-called quenched approximation, accounts for at least some and possibly most of that difference. Overall, the phenomenology of heavy quarkonia as studied in this work is in no conflict with QCD
Advancements in simulations of lattice quantum chromodynamics
International Nuclear Information System (INIS)
Lippert, T.
2008-01-01
An introduction to lattice QCD with emphasis on advanced fermion formulations and their simulation is given. In particular, overlap fermions will be presented, a quite novel fermionic discretization scheme that is able to exactly preserve chiral symmetry on the lattice. I will discuss efficiencies of state-of-the-art algorithms on highly scalable supercomputers and I will show that, due to many algorithmic improvements, overlap simulations will soon become feasible for realistic physical lattice sizes. Finally I am going to sketch the status of some current large scale lattice QCD simulations. (author)
Working group report: Quantum chromodynamics sub-group
Indian Academy of Sciences (India)
with some exercises can be found in [1]. Another main ... be found in [2]. There were two plenary talks: (1) Non-collinearity in high energy scattering .... Soft gluon effects can be controlled at the perturbative level through resumma- tions, and ...
Masses of light quarks in quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Hubschmid, W; Mallik, S [Bern Univ. (Switzerland). Inst. fuer Theoretische Physik
1982-12-28
We try to determine light quark masses by considering sum rules for the vacuum expectation value of the time-ordered correlation function of two divergences of the axial vector current. The evaluation is carried out at momenta high enough for the non-perturbative contributions to be negligible. We find that the average mass of the up and down quark at a momentum of 1 GeV lies between 3.3 and 7.9 MeV while that for the strange quark lies between 84 and 212 MeV. The ranges of values reflect predominantly the uncertainty in the absorptive part in the low energy region (approx. <= 1.7 GeV).
Two-photon exclusive processes in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1986-07-01
QCD predictions for γγ annihilation into single mesons, meson pairs, and baryon pairs are reviewed. Two-photon exclusive processes provide the most sensitive and practical measure of the distribution amplitudes, and thus a critical confrontation between QCD and experiment. Both the angular distribution and virtual photon mass dependence of these amplitudes are sensitive to the shapes of the phi (chi, Q). Novel effects involving the production of qq anti q anti q states at threshold are also discussed, and a new method is presented for systematically incorporating higher-order QCD corrections in γγ reactions
Quantum chromodynamics results from HERA and JLAB
Indian Academy of Sciences (India)
coverage of various experiments in the x−Q2 plane is indicated in figure 1. ... Recent measurements of electron–proton and electron–nucleus collisions at high ener- gies are ... corresponding to a centre-of-mass energy per nucleon of 7.2 GeV.
Covariance problem in two-dimensional quantum chromodynamics
International Nuclear Information System (INIS)
Hagen, C.R.
1979-01-01
The problem of covariance in the field theory of a two-dimensional non-Abelian gauge field is considered. Since earlier work has shown that covariance fails (in charged sectors) for the Schwinger model, particular attention is given to an evaluation of the role played by the non-Abelian nature of the fields. In contrast to all earlier attempts at this problem, it is found that the potential covariance-breaking terms are identical to those found in the Abelian theory provided that one expresses them in terms of the total (i.e., conserved) current operator. The question of covariance is thus seen to reduce in all cases to a determination as to whether there exists a conserved global charge in the theory. Since the charge operator in the Schwinger model is conserved only in neutral sectors, one is thereby led to infer a probable failure of covariance in the non-Abelian theory, but one which is identical to that found for the U(1) case
From moments to functions in quantum chromodynamics
International Nuclear Information System (INIS)
Bluemlein, Johannes; Klein, Sebastian; Kauers, Manuel; Schneider, Carsten
2009-02-01
Single-scale quantities, like the QCD anomalous dimensions andWilson coefficients, obey difference equations. Therefore their analytic form can be determined from a finite number of moments. We demonstrate this in an explicit calculation by establishing and solving large scale recursions by means of computer algebra for the anomalous dimensions and Wilson coefficients in unpolarized deeply inelastic scattering from their Mellin moments to 3-loop order. (orig.)
Large-Nc quantum chromodynamics and harmonic sums
Indian Academy of Sciences (India)
In the large- limit of QCD, two-point functions of local operators become harmonic sums. I review some properties which follow from this fact and which are relevant for phenomenological applications. This has led us to consider a class of analytic number theory functions as toy models of large- QCD which also is ...
Lattice quantum chromodynamics with approximately chiral fermions
International Nuclear Information System (INIS)
Hierl, Dieter
2008-05-01
In this work we present Lattice QCD results obtained by approximately chiral fermions. We use the CI fermions in the quenched approximation to investigate the excited baryon spectrum and to search for the Θ + pentaquark on the lattice. Furthermore we developed an algorithm for dynamical simulations using the FP action. Using FP fermions we calculate some LECs of chiral perturbation theory applying the epsilon expansion. (orig.)
Canonical ensembles and nonzero density quantum chromodynamics
International Nuclear Information System (INIS)
Hasenfratz, A.; Toussaint, D.
1992-01-01
We study QCD with nonzero chemical potential on 4 4 lattices by averaging over the canonical partition functions, or sectors with fixed quark number. We derive a condensed matrix of size 2x3xL 3 whose eigenvalues can be used to find the canonical partition functions. We also experiment with a weight for configuration generation which respects the Z(3) symmetry which forces the canonical partition function to be zero for quark numbers that are not multiples of three. (orig.)
Conformally covariant composite operators in quantum chromodynamics
International Nuclear Information System (INIS)
Craigie, N.S.; Dobrev, V.K.; Todorov, I.T.
1983-03-01
Conformal covariance is shown to determine renormalization properties of composite operators in QCD and in the C 6 3 -model at the one-loop level. Its relevance to higher order (renormalization group improved) perturbative calculations in the short distance limit is also discussed. Light cone operator product expansions and spectral representations for wave functions in QCD are derived. (author)
Lattice quantum chromodynamics with approximately chiral fermions
Energy Technology Data Exchange (ETDEWEB)
Hierl, Dieter
2008-05-15
In this work we present Lattice QCD results obtained by approximately chiral fermions. We use the CI fermions in the quenched approximation to investigate the excited baryon spectrum and to search for the {theta}{sup +} pentaquark on the lattice. Furthermore we developed an algorithm for dynamical simulations using the FP action. Using FP fermions we calculate some LECs of chiral perturbation theory applying the epsilon expansion. (orig.)
Calculations in external fields in quantum chromodynamics
International Nuclear Information System (INIS)
Novikov, V.A.; Shifman, M.A.; Vairshtejn, A.I.; Zakharov, V.I.
1983-01-01
The technique of calculation of operator expansion coefficients is reviewed. The main emphasis is put on gluon operators which appear in expansion of n-point functions induced by colourless quark currents. Two convenient schemes are discussed in detail: the abstract operator method and the method based on the Fock-Schwinger gauge for the vacuum gluon field. A large number of instructive examples important from the point of view of physical applications is considered
Quarks-bags phase transition in quantum chromodynamics
International Nuclear Information System (INIS)
Gorenshtejn, M.I.
1981-01-01
Phase transitions in the quark-gluon plasma are considered at finite temperatures and chemical potentials. A phenomenological account for a complicated structure of the QCD vacuum results in the necessity to use the formalism of isobaric ensembles to describe the system. The phase transition curve separating the regions of the quark-gluon plasma and the hadronic bag phase in the μT plane is calculated [ru
Testing quantum chromodynamics in anti-proton reactions
International Nuclear Information System (INIS)
Brodsky, S.J.
1987-10-01
An experimental program with anti-protons at intermediate energy can serve as an important testing ground for QCD. Detailed predictions for exclusive cross sections at large momentum transfer based on perturbative QCD and the QCD sum rule form of the proton distribution amplitude are available for anti p p → γγ for both real and virtual photons. Meson-pair and lepton-pair final states also give sensitive tests of the theory. The production of charmed hadrons in exclusive anti p p channels may have a non-negligible cross section. Anti-proton interactions in a nucleus, particularly J/psi production, can play an important role in clarifying fundamental QCD issues, such as color transparency, critical length phenomena, and the validity of the reduced nuclear amplitude phenomenology
Constraining neutron star matter with Quantum Chromodynamics
Kurkela, Aleksi; Schaffner-Bielich, Jurgen; Vuorinen, Aleksi
2014-01-01
In recent years, there have been several successful attempts to constrain the equation of state of neutron star matter using input from low-energy nuclear physics and observational data. We demonstrate that significant further restrictions can be placed by additionally requiring the pressure to approach that of deconfined quark matter at high densities. Remarkably, the new constraints turn out to be highly insensitive to the amount --- or even presence --- of quark matter inside the stars.
Bose form of two-dimensional quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Baluni, V [Institute for Advanced Study, Princeton, NJ (USA); Stanford Linear Accelerator Center, CA (USA))
1980-03-01
By means of a special choice of gauge QCD/sub 2/(SU(N)) with one flavor of quarks is recast into the Bose form. Weak (g < m) and strong (g > m) coupling regimes are studied. The former is shown to be the SU(N)-symmetric confining phase in which bound states possess stringlike configurations with strings being represented by electric vortex lines; the ordinary mesons and baryons appear as longitudinal modes of electric strings. The strong coupling regime describes the Higgs phase with the residual symmetry (U(1))/sup N-1/ S/sub N/ where the left and right factors are the maximal abelian subgroup of SU(N) and the permutation group of N quarks, respectively; the particle spectrum consists of S/sub N/ multiplets adn the (U(1))/sup N-1/ charges are trapped.
From moments to functions in quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Bluemlein, Johannes; Klein, Sebastian [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Kauers, Manuel; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation
2009-02-15
Single-scale quantities, like the QCD anomalous dimensions andWilson coefficients, obey difference equations. Therefore their analytic form can be determined from a finite number of moments. We demonstrate this in an explicit calculation by establishing and solving large scale recursions by means of computer algebra for the anomalous dimensions and Wilson coefficients in unpolarized deeply inelastic scattering from their Mellin moments to 3-loop order. (orig.)
Radiative transitions in quarkonjum and quantum chromodynamics
International Nuclear Information System (INIS)
Khodjamirian, A.Yu.
1980-01-01
A new approach to the radiative transitions in quarkonium (c, anti c, b anti b, ...) based on the asymptotic freedom of QCD and on the analyticity is proposed. This approach consists in derivation of dispersion sum rules relating the transition amplitudes with triangle quark diagrams. In this way, a possibility emerges to estimate these amplitudes in a model-independent way. The sum rules are obtained in zeroth order of QCD for transitions between C-even levels 0 ++ , 1 ++ , 2 ++ , 0 -+ and vector (1 -- ) levels. The influence of gluon corrections is discussed and the optimum moments of sum rules are chosen for which these corrections are expected to be at the level of O(αsub(s)) approximately 20%. The widths of radiative transitions in charmonium calculated by means of sum rules turn out to be in agreement with available experimental data. The estimates for analogous transitions in b-quarkonium are also presented. The suggested approach is compared with nonrelativistic models of radiative transitions [ru
[Experimental and theoretical basic research in high energy physics
International Nuclear Information System (INIS)
1991-01-01
This report discusses the measurement of charm and b decays via hadronic production in a hybrid emulsion spectrometer, quantum chromodynamics, quantum electrodynamics, weak interactions, and cosmological applications
International Nuclear Information System (INIS)
Marciano, W.J.
1984-12-01
The present state of the art in elementary particle theory is reviewed. Topics include quantum electrodynamics, weak interactions, electroweak unification, quantum chromodynamics, and grand unified theories. 113 references
International Nuclear Information System (INIS)
Abramov, V.V.; Baldin, V.Yu.; Buzulutskov, A.F.
1981-01-01
The process of pion pair production is studied in the 70 GeV pp collisions. The invariant cross section slope of the pp → π + π - + X process as a function of transverse mompsub(T)entum is found to have a break near 1 GeV/c. Fitting the cross section by a sum of two exponents gives the values of powers (12.3+-0.9) (GeV/c) -1 and (8.7+-0.6) (GeV/c) -1 . The experimental points at psub(T)>=1 GeV/c are significantly higher than predictions based on hard scattering models such as quantum chromodynamics and constituent interchange model. The largest disagreement is discovered for calculations of the cross section in the framework of quantum chromodynamics [ru
International Nuclear Information System (INIS)
Haxton, W.
1990-01-01
This report discusses research in nuclear physics. Topics covered in this paper are: symmetry principles; nuclear astrophysics; nuclear structure; quark-gluon plasma; quantum chromodynamics; symmetry breaking; nuclear deformation; and cold fusion
Intriguing solutions of the Bethe-Salpeter equation for radially excited pseudoscalar charmonia
Czech Academy of Sciences Publication Activity Database
Šauli, Vladimír
2014-01-01
Roč. 90, č. 1 (2014), 016005 ISSN 1550-7998 Institutional support: RVO:61389005 Keywords : quantum chromodynamics * confinement * quarks * gluons Subject RIV: BE - Theoretical Physics Impact factor: 4.643, year: 2014
Pramana – Journal of Physics | Indian Academy of Sciences
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics; Volume 75; Issue 3 ... Chemical potential and internal energy of the noninteracting Fermi gas in ... improved perturbation theory in a quantum chromodynamics inspired potential model.
The iterative hopping expansion algorithm for Monte Carlo calculations with very light fermions
International Nuclear Information System (INIS)
Montvay, I.
1985-03-01
The number of numerical operations necessary for a Monte Carlo simulation with very light fermions (like u- and d-quarks in quantum chromodynamics) is estimated within the iterative hopping expansion method. (orig.)
Spin-isospin mixing without spontaneous symmetry breakdown
International Nuclear Information System (INIS)
Mukherjee, A.; Roy, P.
1983-01-01
The phenomenon advertised in the title is demonstrated in an exactly symmetric SU(2) classical gauge theory with a scalar isodoublet of matter fields. Possible implications for chromodynamics are discussed briefly. (orig.)
Moments of unpolarized nucleon structure functions in chirally improved lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Goeckeler, Meinulf; Maurer, Thilo; Schaefer, Andreas [University of Regensburg (Germany); Lang, Christian B.; Limmer, Markus [University of Graz (Austria)
2008-07-01
We present our results for the lowest moments of unpolarized nucleon structure functions at leading twist. We employ lattice quantum chromodynamics using chirally improved fermions in quenched as well as dynamical simulations.
W+jets in pp collisions at 7 TeV with ATLAS
Indian Academy of Sciences (India)
2012-10-05
Oct 5, 2012 ... energy proton–proton (pp) environment also leads to increased contributions of qg and ... calculations in perturbative quantum chromodynamics (pQCD). ... from multiparton matrix element generators ALPGEN [11] and ...
Research in high energy physics
International Nuclear Information System (INIS)
1992-01-01
This report discusses research being conducted in high energy physics in the following areas; quantum chromodynamics; drift chambers; proton-antiproton interactions; particle decays; particle production; polarimeters; quark-gluon plasma; and conformed field theory
Phase diagram of two-color quark matter at nonzero baryon and isospin density
Czech Academy of Sciences Publication Activity Database
Andersen, J. O.; Brauner, Tomáš
2010-01-01
Roč. 81, č. 9 (2010), 096004/1-096004/14 ISSN 0556-2821 Institutional research plan: CEZ:AV0Z10480505 Keywords : COLOR SUPERCONDUCTIVITY * QUANTUM CHROMODYNAMICS * PERTURBATION-THEORY Subject RIV: BE - Theoretical Physics
Indian Academy of Sciences (India)
Synchronization enhancement via an oscillatory bath in a network of self-excited cells. B R Nana ... Particle Physics. Form factors and charge radii in a quantum chromodynamics-inspired potential .... Geophysics, Astronomy and Astrophysics.
Strong interaction at finite temperature
Indian Academy of Sciences (India)
Quantum chromodynamics; finite temperature; chiral perturbation theory; QCD sum rules. PACS Nos 11.10. ..... at finite temperature. The self-energy diagrams of figure 2 modify it to ..... method of determination at present. Acknowledgement.
Research in high energy physics
International Nuclear Information System (INIS)
1992-01-01
This report discusses research being conducted in high energy physics in the following areas: quantum chromodynamics; drift chambers; proton-antiproton interactions; particle decays; particle production; polarimeters; quark-gluon plasma; and conformed field theory
Dijet physics with CMS detector at the Large Hadron Collider
Indian Academy of Sciences (India)
2012-10-06
Oct 6, 2012 ... Hadron Collider, at a proton–proton collision energy of. √ ... generator predicts less azimuthal decorrelation than observed in data [8]. ... The dijet mass spectrum predicted by quantum chromodynamics (QCD) falls smoothly.
Quarks and numerical simulation
International Nuclear Information System (INIS)
Weingarten, D.
1996-01-01
This work deals with the quantum chromodynamics and the theory of quarks's behaviour. The experimentation supports this theory but until now no computation have prove it. The resolution of the mathematic equations were far beyond the capability of human or the quickest computer of the seventies. A dedicated computer was built: the GF11. The mass of eight hadrons was computed in 91. In 95, a new particle was found by computation. The author explains the mathematical modeling of chromodynamics and the methods to solve it. It requires 10 17 arithmetic operations. So specific computer is needed. GF11 uses 566 processors in parallel. New machines hundred of times more efficient will be needed to go further. That will be a new tool for theorician physicists. (O.M.). 9 refs., 2 figs., 1 tab
Testing strong interaction theories
International Nuclear Information System (INIS)
Ellis, J.
1979-01-01
The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)
Heavy-quark QCD vacuum polarisation function. Analytical results at four loops
International Nuclear Information System (INIS)
Kniehl, B.A.; Kotikov, A.V.
2006-07-01
The first two moments of the heavy-quark vacuum polarisation function at four loops in quantum chromo-dynamics are found in fully analytical form by evaluating the missing massive four-loop tadpole master integrals. (orig.)
Top physics with 0.70–1.08 fb of pp collisions with the ATLAS ...
Indian Academy of Sciences (India)
With data collected during the first half of the 2011 pp run of the Large Hadron ... Top quarks; quantum chromodynamics experimental tests; Kaluza–Klein excitations. ... background from fake leptons are estimated using data-driven methods.
EMC effect: asymptotic freedom with nuclear targets
International Nuclear Information System (INIS)
West, G.B.
1984-01-01
General features of the EMC effect are discussed within the framework of quantum chromodynamics as expressed via the operator product expansion and asymptotic freedom. These techniques are reviewed with emphasis on the target dependence. 22 references
Measurement of the production cross-section of pairs of isolated ...
Indian Academy of Sciences (India)
2012-10-06
Oct 6, 2012 ... a valuable test of perturbative quantum chromodynamics (pQCD), and this represents a major background to ... Photons are reconstructed by clustering the energy deposited in the ECAL. The trigger ... generator. The diphoton ...
Nuclear theory progress report, April 1991--April 1992
International Nuclear Information System (INIS)
1992-01-01
This report discusses research in nuclear theory on the following topics: nuclear astrophysics; quantum chromodynamics; quark matter; symmetry breaking; heavy ion reactions; hadronic form factors; neutrino processes; nuclear structure; weak interaction physics; and other related topics
Theory and phenomenology of strong and weak interaction high energy physics
International Nuclear Information System (INIS)
1989-01-01
This paper reviews research done on theoretical high energy physics. Areas of discussion are: chiral symmetry; quantum chromodynamics; quark-gluon plasma; particle decay of kaons; photonuclear reactions from cosmic ray showers; symmetry breaking and other related topics
Indian Academy of Sciences (India)
Harvesting solar energy through dye-sensitized and quantum dot solar cell · View presentation. 10.30, Amol ... Exploring quantum chromodynamics phase transitions at RHIC and LHC · View presentation. 15.30-16.00 ... Math and Finance ...
Analysis of hard inclusive processes in quantum chromodynamics
International Nuclear Information System (INIS)
Radyushkin, A.V.
1983-01-01
An approach to the investigation of hard processes in QCD based on a regular usage of α-representation analysis of Feynman diagram asymptotics is described. Analysis is examplified by two simplest inclusive processes: E + e - annihilation into hadrons and deep inelastic lepton-hadron scattering. The separation procedure of factorization of contributions stipulated by short- and long-range particle interactions is reported. The relation between expansion operators and methods based on direct analysis of diagrams as well as between theoretical field approaches and the parton model is discussed. Specific features of factorization of short- and long-range contributions in non-Abelian gauge theories are investigated
Quantum chromodynamics as the sequential fragmenting with inactivation
International Nuclear Information System (INIS)
Botet, R.
1996-01-01
We investigate the relation between the modified leading log approximation of the perturbative QCD and the sequential binary fragmentation process. We will show that in the absence of inactivation, this process is equivalent to the QCD gluodynamics. The inactivation term yields a precise prescription of how to include the hadronization in the QCD equations. (authors)
Quantum chromodynamics as the sequential fragmenting with inactivation
Energy Technology Data Exchange (ETDEWEB)
Botet, R. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique des Solides; Ploszajczak, M. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France)
1996-12-31
We investigate the relation between the modified leading log approximation of the perturbative QCD and the sequential binary fragmentation process. We will show that in the absence of inactivation, this process is equivalent to the QCD gluodynamics. The inactivation term yields a precise prescription of how to include the hadronization in the QCD equations. (authors). 15 refs.
Quantum chromodynamics effects in electroweak and Higgs physics
Indian Academy of Sciences (India)
background, and instead an excess of events over SM predictions in the tail of a .... bin, this division allows each exclusive jet bin to be optimized independently to ... cross-section and the 1-jet inclusive cross-section have independent per-.
Operator expansion in quantum chromodynamics beyond perturbation theory
International Nuclear Information System (INIS)
Novikov, V.A.; Shifman, M.A.; Vainshtejn, A.I.; Zakharov, V.I.
1980-01-01
The status of operator expansion at short distances is descussed within the frameworks of nonperturbatue QCD. The question of instanton effects is investigated in various aspects. Two-point functions induced by the gluonic currents are considered. It is shown that certain gluonic correlations vanish in the field of definite duality. It is proved that there does exist a very special relation between the expansion coefficients required by consistancy between instanton calculations and the general operator expansion. At last a certain modification of the naive version of operator expansion is proposed, which allows one to go beyond the critical power and construct, if necessary, an infinite series
Quantum chromodynamics and hadronic interactions at short distances
International Nuclear Information System (INIS)
Brodsky, S.J.; Huang, T.; Lepage, G.P.
1982-01-01
The main purpose of this lecture is to begin to extend QCD phenomenology by taking into account the physics of hadronic wavefunctions. The eventual goal is to obtain a parametrization of the wavefunctions which will bridge the gap between the non-perturbative and perturbative aspects of QCD. The lack of knowledge of hadronic matrix elements is the main difficulty in computing and normalizing dynamical higher twist contributions for many processes
Quantum chromodynamics with infinite number of vector mesons
International Nuclear Information System (INIS)
Geshkenbejn, B.V.
1988-01-01
Families of vector mesons Ρ,Ψ,Υ, contain an infinite number of resonances with gradually increasing widths are considered. The asymptotic freedom requirement involves a relationship between the electric width of k-th resonance and its mass M k derivative over the number k. It is shown that for the families of Ψ and Υ mesons the moment from experimental function R(s) is equal to the sum of the moment from a bare quark loop and the edge term which stems from replacing of summation by integration. These equalities are fulfilled up to 1% for 60 moments in the Ψ-meson family and up to 2% for 96 moments in the Υ-meson family. The electronic widths of the resonances and the Ρ-meson mass are calculated. 7 refs
Mechanical analog for a quantum-chromodynamic phase transition
International Nuclear Information System (INIS)
Salomone, A.; Schechter, J.
1982-01-01
A simple mechanical model involving a pendulum and a spring is shown to give the same phase-transition behavior as that of either the effective chiral Lagrangian for one-flavor QCD or the massive Schwinger model. This model, which also has been studied in catastrophe theory, permits us to get a nice understanding of what at first appears to be a complicated system. We also construct and analyze a mechanical analog model for the two-flavor case. The latter has a similar behavior, in general, but does present some interesting new features. With this experience under our belts we are able to straightforwardly analyze the situation with an arbitrary number of flavors. We also discuss what the zero-flavor (i.e., pure QCD) limit of the effective Lagrangian should look like and give a formula for the ground-state energy as a function of the instanton angle theta. A number of other questions related to the QCD effective Lagrangian are investigated
Strangeness of the nucleon from lattice quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Alexandrou, Constantia [The Cyprus Institute, Nicosia (Cyprus). Computation-based Science and Technology Research Center (CaSToRC); Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Constantinou, Martha; Hadjiyiannakou, Kyriakos [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Dinter, Simon; Drach, Vincent [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Jansen, Karl [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Koutsou, Giannis; Vaquero, Alejandro [The Cyprus Institute, Nicosia (Cyprus). Computation-based Science and Technology Research Center (CaSToRC); Collaboration: ETM Collaboration
2013-10-15
We present a non-perturbative calculation of the strangeness of the nucleon y{sub N} within the framework of lattice QCD. This observable is known to be an important cornerstone to interpret results from direct dark matter detection experiments. We perform a lattice computation for y{sub N} with an analysis of systematic effects originating from discretization, finite size, chiral extrapolation and excited state effects leading to a value of y{sub N}=0.135(46) which turns out to be rather small. As a main result of our work, we demonstrate that the error for y{sub N} is dominated by systematic uncertainties.
Studies of quantum chromodynamics with the ALEPH detector
Barate, R; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Odier, P; Pietrzyk, B; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Delfino, M C; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Orteu, S; Padilla, C; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; 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; Alemany, R; Bazarko, A O; Bright-Thomas, P G; Cattaneo, M; Cerutti, F; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Lohse, T; Lutters, G; Mato, P; Minten, Adolf G; Miquel, R; Mir, L M; Moneta, L; Oest, T; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rizzo, G; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schmitt, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Ferdi, C; Gay, P; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J B; 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; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, E; Thomson, F; Turnbull, R M; Becker, U; Buchmüller, O L; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Moutoussi, A; Nash, J; Sedgbeer, J K; Stacey, A M; Williams, M D; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Williams, M I; Barczewski, T; Galla, A; Giehl, I; Greene, A M; Hoffmann, C; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Schmidt, H; Steeg, F; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Coyle, P; Diaconu, C A; Etienne, F; Konstantinidis, N P; Leroy, O; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Ragusa, F; Berlich, R; Blum, Walter; Büscher, V; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; 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; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Park, H J; Schune, M H; Simion, S; Veillet, J J; Videau, I; Zerwas, 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; Palla, Fabrizio; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Verdini, P G; Blair, G A; Bryant, L M; Chambers, J T; Gao, Y; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Bertin, V; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; 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; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Dawson, I; Kelly, M S; Lehto, M H; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Minguet-Rodríguez, J A; Rivera, F; 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; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Greening, T C; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G
1998-01-01
Previously published and as yet unpublished QCD results obtained with the ALEPH detector at LEP1 are presented. The unprecedented statistics allows detailed studies of both perturbative and non-perturbative aspects of strong interactions to be carried out using hadronic Z and tau decays. The studies presented include precise determinations of the strong coupling constant, tests of its flavour independence, tests of the SU(3) gauge structure of QCD, study of coherence effects, and measurements of single-particle inclusive distributions and two-particle correlations for many identified baryons and mesons.
V = 1 super quantum chromodynamics and fractional branes
Indian Academy of Sciences (India)
The orbifold group acts on the directions x4,...,x9 transverse to the world-volume of the stack of the N D3-branes. The Z2 group is characterized by two elements 1, h , with h2 = 1, hence the four elements of the tensor product Z2 ¢Z2 are easily obtained. The non-trivial elements act on the complex vector z = (z1 = x4 + ix5, ...
Chiral phase transitions in quantum chromodynamics at finite ...
Indian Academy of Sciences (India)
at finite temperature: Hard-thermal-loop resummed ... (ii) To closely estimate the dominant temperature effects, we focus on studying the DS equation being .... method is useful so long as the convergence of the iteration is guaranteed. At each ...
Double-beta decay processes from lattice quantum chromodynamics
Davoudi, Zohreh; Tiburzi, Brian; Wagman, Michael; Winter, Frank; Chang, Emmanuel; Detmold, William; Orginos, Kostas; Savage, Martin; Shanahan, Phiala; Nplqcd Collaboration
2017-09-01
While an observation of neutrinoless double-beta decay in upcoming experiments will establish that the neutrinos are Majorana particles, the underlying new physics responsible for this decay can only be constrained if the theoretical predictions of the rate are substantially refined. This talk demonstrates the roadmap in connecting the underlying high-scale theory to the corresponding nuclear matrix elements, focusing mainly on the nucleonic matrix elements in the simplest extension of Standard Model in which a light Majorana neutrino is mediating the process. The role of lattice QCD and effective field theory in this program, in particular, the prospect of a direct matching of the nn to pp amplitude to lattice QCD will be discussed. As a first step towards this goal, the results of the first lattice QCD calculation of the relevant matrix element for neutrinofull double-beta decay will be presented, albeit with unphysical quark masses, along with important lessons that could impact the calculations of nuclear matrix elements involved in double-beta decays of realistic nuclei.
Photon pairs: Quantum chromodynamics continuum and the Higgs ...
Indian Academy of Sciences (India)
Resummation is needed to obtain reliable predictions in the range of transverse momentum where the cross-section is the largest. Results are compared with data from the Fermilab Tevatron and predictions are made for the large hadron collider. The QCD continuum is shown to have a softer spectrum than the Higgs boson ...
Fermions in light front transverse lattice quantum chromodynamics
Indian Academy of Sciences (India)
Ur(x-aˆr)]}. (3). After eliminating the constraint fields we arrive at the transverse lattice Hamiltonian. P. =P. 1 +P. 2 ,. (4) where P. 1 arises from the elimination of ψ (hence sensitive to how fermions are put on the transverse lattice) and P. 2 contains Wilson plaquette term and the terms arising from the elimination of A . Explicitly.
Nuclear chromodynamics: Novel nuclear phenomena predicted by QCD
Bakker, B.L.G.; Ji, C.R.
2014-01-01
With the acceptance of QCD as the fundamental theory of strong interactions, one of the basic problems in the analysis of nuclear phenomena became how to consistently account for the effects of the underlying quark/gluon structure of nucleons and nuclei. Besides providing more detailed understanding
Sum rules and exclusive processes in quantum chromodynamics
International Nuclear Information System (INIS)
Radyushkin, A.V.
1983-01-01
A brief review of results of analyzing hadron form factors is presented. The analysis of hardron form factors was conducted by the method of QCD sum rules. The method is based on the concept of quark-hadron duality. Correlation of calculation results with available experimental data was performed. The conclusion is made that it is sufficient to consider only the contribution of the simplest diagrams which don't contain gluon exchanges in order to describe experimental data on pion, proton and neutron form factors
Quantum chromodynamics phase transition in the early Universe ...
Indian Academy of Sciences (India)
... quark nuggets have been calculated and it has been found that there are sizeable number of quark nuggets in the stable sector. The nuggets can clump and form bigger objects in the mass range of 0.0003 M ⊙ to 0.12 M ⊙ . It has been discussed that these bigger objects can be possible candidates for cold dark matter.
Results on nucleon structure functions in quantum chromodynamics
International Nuclear Information System (INIS)
Martin, F.
1979-01-01
Gluon bremsstrahlung processes inside the nucleon are investigated using the standard renormalization-group analysis. A new method of inverting the moments is applied which leads to analytic results for the parton distributions near x = 1 and x = 0. The nucleon is considered as a bound state of three quarks subsequently ''renormalized'' by gluon bremsstrahlung and quark-antiquark pair production. An ''unrenormalized'' valance quark distribution peaked at x = 1/3, with a width related to the nucleon radius, leads to good agreement with deep-inelastic data. However, the gluon distribution obtained seems too steep near x = 0
Vector current scattering in two dimensional quantum chromodynamics
International Nuclear Information System (INIS)
Fleishon, N.L.
1979-04-01
The interaction of vector currents with hadrons is considered in a two dimensional SU(N) color gauge theory coupled to fermions in leading order in an N -1 expansion. After giving a detailed review of the model, various transition matrix elements of one and two vector currents between hadronic states were considered. A pattern is established whereby the low mass currents interact via meson dominance and the highly virtual currents interact via bare quark-current couplings. This pattern is especially evident in the hadronic contribution to inelastic Compton scattering, M/sub μν/ = ∫ dx e/sup iq.x/ , which is investigated in various kinematic limits. It is shown that in the dual Regge region of soft processes the currents interact as purely hadronic systems. Modification of dimensional counting rules is indicated by a study of a large angle scattering analog. In several hard inclusive nonlight cone processes, parton model ideas are confirmed. The impulse approximation is valid in a Bjorken--Paschos-like limit with very virtual currents. A Drell--Yan type annihilation mechanism is found in photoproduction of massive lepton pairs, leading to identification of a parton wave function for the current. 56 references
AdS gravity and the scalar glueball spectrum
Energy Technology Data Exchange (ETDEWEB)
Vento, Vicente [Departament de Fisica Teorica, Universitat de Valencia y Institut de Fisica Corpuscular, Consejo Superior de Investigaciones Cientificas, Burjassot (Valencia) (Spain)
2017-09-15
The scalar glueball spectrum has attracted much attention since the formulation of Quantum Chromodynamics. Different approaches give very different results for the glueball masses. We revisit the problem from the perspective of the AdS/CFT correspondence. (orig.)
The properties of C-parameter and coupling constants
Indian Academy of Sciences (India)
2016-12-03
Dec 3, 2016 ... We present the properties of the C-parameter as an event-shape variable. We calculate the ... ideal testing ground to study quantum chromodynam- ics (QCD) and these ... soid with orthogonal axes named minor, semimajor. 1 ...
The three loop two-mass contribution to the gluon vacuum polarization
Energy Technology Data Exchange (ETDEWEB)
Bluemlein, J.; Freitas, A. de; Schoenwald, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC)
2017-10-15
We calculate the two-mass contribution to the 3-loop vacuum polarization of the gluon in Quantum Chromodynamics at virtuality p{sup 2}=0 for general masses and also present the analogous result for the photon in Quantum Electrodynamics.
Deep inelastic lepton scattering
International Nuclear Information System (INIS)
Nachtmann, O.
1977-01-01
Deep inelastic electron (muon) nucleon and neutrino nucleon scattering as well as electron positron annihilation into hadrons are reviewed from a theoretical point of view. The emphasis is placed on comparisons of quantum chromodynamics with the data. (orig.) [de
Asymptotic freedom without guilt
International Nuclear Information System (INIS)
Ma, E.
1979-01-01
The notion of asymptotic freedom in quantum chromodynamics is explained on general physical grounds, without invoking the formal arguments of renormalizable quantum field theory. The related concept of quark confinement is also discussed along the same line. 5 references
Analytical solution for the correlator with Gribov propagators
Czech Academy of Sciences Publication Activity Database
Šauli, Vladimír
2016-01-01
Roč. 14, č. 1 (2016), s. 570-578 E-ISSN 2391-5471 Institutional support: RVO:61389005 Keywords : confinement * Gribov propagator * Quantum Chromodynamics * dispersion relations * quantum field theory * Green's functions Subject RIV: BE - Theoretical Physics Impact factor: 0.745, year: 2016
Jet fragmentation and predictions of the resummed perturbative QCD
Energy Technology Data Exchange (ETDEWEB)
Safonov, Alexei Nikolayevich [Univ. of Florida, Gainesville, FL (United States)
2001-01-01
This dissertation is dedicated to the experimental analysis of jet fragmentation, the process of formation of jets of particles produced in high-energy collisions, and to the comparison of the results to the predictions of resummed perturbative calculations within Quantum Chromodynamics.
Two-dimensional models in statistical mechanics and field theory
International Nuclear Information System (INIS)
Koberle, R.
1980-01-01
Several features of two-dimensional models in statistical mechanics and Field theory, such as, lattice quantum chromodynamics, Z(N), Gross-Neveu and CP N-1 are discussed. The problems of confinement and dynamical mass generation are also analyzed. (L.C.) [pt
Problems of high energy physics
International Nuclear Information System (INIS)
Kadyshevskij, V.G.
1989-01-01
Some problems of high energy physics are discussed. The main attention is paid to describibg the standard model. The model comprises quantum chromodynamics and electroweak interaction theory. The problem of CP breaking is considered as well. 8 refs.; 1 tab
International Nuclear Information System (INIS)
Khoze, V.A.
1983-10-01
We discuss the results accumulated during the last five years in heavy quark physics and try to draw a simple general picture of the present situation. The survey is based on a unified point of view resulting from quantum chromodynamics. (orig.)
International Nuclear Information System (INIS)
Ajduk, Z.
1985-01-01
These proceedings contain 47 lectures held at the symposium. They deal with pbar-p collider results, phenomenology of electroweak effects, high energy lepton interactions, high energy hadron interactions, quantum chromodynamics, bag model, grand unification, supersymmetry and superstring theory. (M.F.W.)
International Nuclear Information System (INIS)
Landshoff, P.V.
1983-01-01
The author describes the application of quantum chromodynamics to deep inelastic lepton scattering, the Drell-Yan process, e + e - -annihilation, #betta##betta#-physics, large psub(T) processes, and wide angle quark-quark scattering. Furthermore higher order terms are considered. (HSI)
Probing the neutron star interior and the Equation of State of cold dense matter with the SKA
Watts, A.; Xu, R.; Espinoza, C.; Andersson, N.; Antoniadis, J.; Antonopoulou, D.; Buchner, S.; Dai, S.; Demorest, P.; Freire, P.; Hessels, J.; Margueron, J.; Oertel, M.; Patruno, A.; Possenti, A.; Ransom, S.; Stairs, I.; Stappers, B.
2015-01-01
With an average density higher than the nuclear density, neutron stars (NS) provide a unique testground for nuclear physics, quantum chromodynamics (QCD), and nuclear superfluidity. Determination of the fundamental interactions that govern matter under such extreme conditions is one of the major
Nuclear physics studies with medium energy probes. Progress report and renewal proposal
International Nuclear Information System (INIS)
Seth, K.K.
1986-01-01
Research is concerned with nuclear reactions, nuclear structure, pion production in elementary collisions, symmetry tests, and searches for dibaryon structures. Increasing emphasis is being placed on fundamental problems relating to quantum chromodynamics. A list of publications is provided. 43 refs., 12 figs
A variational approach to bag formation and the quark-antiquark potential
International Nuclear Information System (INIS)
Akiba, T.; Takagi, F.
1983-01-01
A variational approach is used to the Adler problem which is to obtain the color confinement region and the q-anti q static potential from approxiamte effective potentials of quantum chromodynamics. It yields fairly good fits to the Adler-Piran numerical results. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Pendlebooth, G. (Edinburgh Univ. (UK). Dept. of Physics)
1991-01-05
The use of supercomputers to generate lattice Monte Carlo simulations of the Standard Model in quantum mechanics is described. Researchers in the field of quantum chromodynamics need this method of testing theory against observation as paper calculation are too complex and difficult. (UK).
International Nuclear Information System (INIS)
Aubert, J.J.
1982-01-01
Deep inelastic lepton-nucleon interaction experiments are renewed. Singlet and non-singlet structure functions are measured and the consistency of the different results is checked. A detailed analysis of the scaling violation is performed in terms of the quantum chromodynamics predictions [fr
Czech Academy of Sciences Publication Activity Database
Aaboud, M.; Aad, G.; Abbott, B.; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Penc, Ondřej; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2016-01-01
Roč. 762, Nov (2016), 1-22 ISSN 0370-2693 Institutional support: RVO:68378271 Keywords : ATLAS * quantum chromodynamics * perturbation theory * charge dependence * CERN LHC Coll * phase space Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.807, year: 2016
Indian Academy of Sciences (India)
Bedangadas Ph.D. (IoP, Bhubaneswar), FNA, FNASc. Date of birth: 8 April 1973. Specialization: Dark Matter, Experimental High Energy Physics, Phase Diagram of Quantum Chromodynamics Address: School of Physical Sciences, National Institute of Science Education & Research, Jatni, Khordha 752 050, Orissa Contact:
Pramana – Journal of Physics | Indian Academy of Sciences
Indian Academy of Sciences (India)
We describe the calculation of inclusive Higgs boson production at hadronic colliders at next-to-next-to-leading order (NNLO) in perturbative quantum chromodynamics. We have used the technique developed in ref. [4]. Our results agree with those published earlier in the literature.
Thermodynamic Study for Conformal Phase in Large Nf Gauge Theory
Miura, Kohtaroh; Lombardo, Maria Paola; Pallante, Elisabetta
2011-01-01
We investigate the chiral phase transition at finite temperature (T) in colour SU(3) Quantum Chromodynamics (QCD) with six species of fermions (Nf = 6) in the fundamental representation. The simulations have been performed by using lattice QCD with improved staggered fermions. The critical couplings
Theoretical high energy physics
International Nuclear Information System (INIS)
Lee, T.D.
1992-01-01
This progress report discusses research by Columbia University staff in high energy physics. Some of the topics discussed are as follows: lattice gauge theory; quantum chromodynamics; parity doublets; solitons; baryon number violation; black holes; magnetic monopoles; gluon plasma; Chern-Simons theory; and the inflationary universe
International Nuclear Information System (INIS)
Drell, S.D.
1978-01-01
The concept of elementary constituents or ultimate building blocks of nature in recent years is reviewed. The quark hypothesis, neutrinos, color, hard collisions, psi and other recent resonances, flavor, quantum chromodynamics, the tau particle, and particle structure are among the ideas considered. 22 references
Monte Carlo simulations in theoretical physic
International Nuclear Information System (INIS)
Billoire, A.
1991-01-01
After a presentation of the MONTE CARLO method principle, the method is applied, first to the critical exponents calculations in the three dimensions ISING model, and secondly to the discrete quantum chromodynamic with calculation times in function of computer power. 28 refs., 4 tabs
Study of event shape variables at LEP
Sarkar, Subir
1997-01-01
We present the LEP results on the study of the hadronic event shape variables. Excellent detector performance and improved theoretical calculations make it possible to study quantum chromodynamics with small experimental and theoretical uncertainties. QCD predictions describe data well at energies above the Z peak.
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Penc, Ondřej; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2016-01-01
Roč. 754, Mar (2016), 302-322 ISSN 0370-2693 Institutional support: RVO:68378271 Keywords : ATLAS * angular distribution * quantum chromodynamics * perturbation theory * contact interaction * new interaction * CERN LHC Coll Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.807, year: 2016
Techniques in meson spectroscopy
International Nuclear Information System (INIS)
Longacre, R.S.
1991-01-01
This report contains lectures on the following topics: the quark model and beyond using quantum chromodynamics; analysis of formation reactions; energy dependence of the partial wave amplitudes; where the data for the t-matrix analysis comes from; and coupled channel analysis of isoscalar mesons
International Nuclear Information System (INIS)
Lee, T.S.H.
1988-01-01
A πNN model inspired by Quantum Chromodynamics is presented. The model gives an accurate fit to the most recent Arndt NN phase shifts up to 1 GeV and can be applied to study intermediate- and high-energy nuclear reactions. 20 refs., 2 figs
Weak decays of stable particles
International Nuclear Information System (INIS)
Brown, R.M.
1988-09-01
In this article we review recent advances in the field of weak decays and consider their implications for quantum chromodynamics (the theory of strong interactions) and electroweak theory (the combined theory of electromagnetic and weak interactions), which together form the ''Standard Model'' of elementary particles. (author)
Indian Academy of Sciences (India)
Anuradha Misra. Articles written in Pramana – Journal of Physics. Volume 63 Issue 6 December 2004 pp 1367-1379. Working group report: Quantum chromodynamics · Prakash Mathewes Rahul Basu D Indumathi E Laenen Swapan Majhi Anuradha Misra Asmita Mukherjee W Vogelsang · More Details Abstract Fulltext PDF.
Weak decay amplitudes in large N/sub c/ QCD
International Nuclear Information System (INIS)
Bardeen, W.A.
1988-10-01
A systematic analysis of nonleptonic decay amplitudes is presented using the large N/sub c/ expansion of quantum chromodynamics. In the K-meson system, this analysis is applied to the calculation of the weak decay amplitudes, weak mixing and CP violation. 10 refs., 5 figs., 2 tabs
13. international QCD conference (QCD 06)
International Nuclear Information System (INIS)
2006-01-01
This conference was organized around 5 sessions: 1) quantum chromodynamics (QCD) at colliders, 2) CP-violation, Kaon decays and Chiral symmetry, 3) perturbative QCD, 4) physics of light and heavy hadrons, 5) confinement, thermodynamics QCD and axion searches. This document gathers only the slides of the presentations
International Nuclear Information System (INIS)
Becher, P.; Joos, H.
1977-07-01
It is the aim of the main part of these lectures to show how most of the expected dynamical properties of quantum chromodynamics are realised in 1+1 dimensional quantum electrodynamics. Asymptotic freedom, the infrared limit, quark confinement and bag approximation are discussed in detail. (BJ) [de
Electromagnetic structure of nuclei
International Nuclear Information System (INIS)
Arnold, R.G.
1986-07-01
A brief review is given of selected topics in the electromagnetic structure of nucleons and nuclei, including nucleon form factors from both quantum chromodynamics and electron scattering data, measurements of the deuteron and triton form factors, quasi-elastic scattering, and the EMC effect. 47 refs., 13 figs
Pramana – Journal of Physics | Indian Academy of Sciences
Indian Academy of Sciences (India)
The next-to-leading order (NLO) gluon distribution from DGLAP equation and the logarithmic derivatives of the proton structure function 2 (, ) at low · D K Choudhury ... Slope and curvature of Isgur–Wise function using variationally improved perturbation theory in a quantum chromodynamics inspired potential model.
Pramana – Journal of Physics | Indian Academy of Sciences
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics; Volume 75; Issue 3. Slope and curvature of Isgur–Wise function using variationally improved perturbation theory in a quantum chromodynamics inspired potential model. Bhaskar Jyoti Hazarika D K Choudhury. Research Articles Volume 75 Issue 3 September 2010 pp 423- ...
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.
13. international QCD conference (QCD 06)
Energy Technology Data Exchange (ETDEWEB)
NONE
2006-07-01
This conference was organized around 5 sessions: 1) quantum chromodynamics (QCD) at colliders, 2) CP-violation, Kaon decays and Chiral symmetry, 3) perturbative QCD, 4) physics of light and heavy hadrons, 5) confinement, thermodynamics QCD and axion searches. This document gathers only the slides of the presentations.
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2016-01-01
Roč. 907, Jun (2016), s. 717-763 ISSN 0550-3213 Institutional support: RVO:68378271 Keywords : ATLAS * differential cross section * measured * quantum chromodynamics * perturbation theory * total cross section * CERN LHC Coll Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.678, year: 2016
Indian Academy of Sciences (India)
Probing physics at extreme energies with cosmic ultra-high energy radiation ... Photons from quark gluon plasma and hot hadronic matter ... Quantum chromodynamics phase transition in the early Universe and quark ... A first look at Au+Au collisions at RHIC energies using the PHOBOS de- .... Condensed Matter Physics.
Introduction to the nuclear physics at very high energy
International Nuclear Information System (INIS)
Kodama, T.
1985-01-01
An introduction to the nuclear physics at very high energies on the basis of relativistic nucleus-nucleus, hadron-nucleus and hadron-hadron collisions is made. Some theoretical models used nowadays to explain the experimental data, such as Quantum Chromodynamics, String Model, etc... are presented. (L.C.) [pt
Indian Academy of Sciences (India)
Maji Kaushik. A time-dependent. Fourier grid. Hamiltonian-based formulation of time- dependent multi-configuration Hartree method. L983. Majumdar A S ... N = 1 super quantum chromodynamics and fractional branes. 721. Philip J see Alex A V. 87. Pokorski Stefan. Electroweak breaking and supersymme- try breaking. 369.
Heavy-flavor production and medium properties in high-energy nuclear collisions --What next?
Aarts, G.; Aichelin, J.; Allton, C.; Arnaldi, R.; Bass, S. A.; Bedda, C.; Brambilla, N.; Bratkovskaya, E.; Braun-Munzinger, P.; Bruno, G. E.; Dahms, T.; Das, S. K.; Dembinski, H.; Djordjevic, M.; Ferreiro, E. G.; Frawley, A.; Gossiaux, P. B.; Granier de Cassagnac, R.; Grelli, A.; He, Ming; Horowitz, W. A.; Innocenti, G. M.; Jo, M.; Kaczmarek, O.; Kuijer, P; Laine, M.; Lombardo, M. P.; Mischke, A.; Munhoz, M. G.; Nahrgang, M.; Nguyen, Mai; Oliveira da Silva, A. C.; Petreczky, P.; Rothkopf, A.; Schmelling, M.; Scomparin, E.; Song, Ting; Stachel, J.; Suaide, A. A P; Tolos, L.; Trzeciak, B.; Uras, A.; van Doremalen, L.; Vermunt, L.; Vigolo, S.; Xu, N.; Ye, Z.; Zanoli, H.J.C.; Zhuang, P.
2017-01-01
Open and hidden heavy-flavor physics in high-energy nuclear collisions are entering a new and exciting stage towards reaching a clearer understanding of the new experimental results with the possibility to link them directly to the advancement in lattice Quantum Chromo-Dynamics (QCD). Recent results
Theory explaining it all doesn't quite
2004-01-01
A history of string theory since the first announcement at Aspen by Michael Green and John Schwartz. Among its triumphs are explanations of quantum gravity and the study of black holes but experimental evidence in particle physics supports an alternative theory - that of quantum chromodynamics (2 pages)
Lemon : An MPI parallel I/O library for data encapsulation using LIME
Deuzeman, Albert; Reker, Siebren; Urbach, Carsten
We introduce Lemon, an MPI parallel I/O library that provides efficient parallel I/O of both binary and metadata on massively parallel architectures. Motivated by the demands of the lattice Quantum Chromodynamics community, the data is stored in the SciDAC Lattice QCD Interchange Message
To flow or not to flow : a study of elliptic flow and nonflow in proton-proton collisions in ALICE
van der Kolk, N.
2012-01-01
The standard model of particle physics describes all known elementary particles and the forces between them. The strong force, which binds quarks inside hadrons and nucleons inside nuclei, is described by the theory of Quantum Chromodynamics. This theory predicts a new state of matter at extreme
Pramana – Journal of Physics | Indian Academy of Sciences
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics. Bhaskar Jyoti Hazarika. Articles written in Pramana – Journal of Physics. Volume 75 Issue 3 September 2010 pp 423-438 Research Articles. Slope and curvature of Isgur–Wise function using variationally improved perturbation theory in a quantum chromodynamics inspired ...
Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions
Adam, J.; Adamov, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Prado, C. Alves Garcia; Janssen, M M; Andrei, C.; Andrews, H. A.; Andronic, A.; Anguelov, V.; Anticic, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Balasubramanian, S.; Baldisseri, A.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnafldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Camejo, A. Batista; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Martinez, H. Bello; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Beltran, L. G. E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielcík, J.; Bielcíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Bjelogrlic, S.; Blair, J. T.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Bonora, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caarri, D.; Cai, X.; Caines, H.; Diaz, L. Calero; Caliva, A.; Villar, E. Calvo; Camerini, P.; Carena, F.; Carena, W.; Carnesecchi, F.; Castellanos, J. Castillo; Castro, A. J.; Casula, E. A R; Sanchez, C. Ceballos; Cepila, J.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Barroso, V. Chibante; Chinellato, D. D.; Cho, Sukhee; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Balbastre, G. Conesa; Del Valle, Z. Conesa; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Morales, Y. Corrales; Maldonado, I. Cortés; Cortese, P.; Cosentino, M. R.; Costa, F.; Crkovska, J.; Crochet, P.; Albino, R. Cruz; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; Dasgupta, S. S.; De Caro, A.; De Cataldo, G.; De Conti, C.; De Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Souza, R. Derradi; Deisting, A.; Delo, A.; Dénes, E.; Deplano, C.; Dhankher, P.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Di Ruzza, B.; Corchero, M. A Diaz; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, O.; Dobrin, A.; Gimenez, D. Domenicis; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erdemir, I.; Erhardt, F.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Téllez, A. Fernández; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A S; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; De Francisco, A.; Frankenfeld, U.; Fronze, G. G.; Fuchs, U.; Furget, C.; Furs, A.; Girard, M. Fusco; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gajdosova, K.; Gallio, M.; Galvan, C. D.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Garg, K.; Gargiulo, C.; Gasik, P.; Gauger, E. F.; Germain, M.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Coral, D. M.Goméz; Ramirez, A. Gomez; Gonzalez, A. S.; Gonzalez, V; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Grachov, O. A.; Graczykowski, L. K.; Graham, K. L.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gronefeld, J. M.; Grosse-Oetringhaus, J. F.; Grosso, R.; Gruber, L.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hamon, J. C.; Harris, J. W.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Hellbär, E.; Helstrup, H.; Herghelegiu, A.; Corral, G. Herrera; Herrmann, F.; Hess, B. A.; Hetland, K. F.; Hillemanns, H.; Hippolyte, B.; Horak, D.; Hosokawa, R.; Hristov, P.; Hughes, C.W.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Inaba, M.; Incani, E.; Ippolitov, M.; Irfan, M.; Isakov, V.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacak, B.; Jacazio, N.; Jacobs, P. M.; Jadhav, M. B.; Jadlovska, S.; Jadlovsky, J.; Jahnke, C.; Jakubowska, M. J.; Janik, M. A.; Jayarathna, P. H S Y; Jena, C.; Jena, S.; Bustamante, R. T Jimenez; Jones, P. G.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kang, J. H.; Kaplin, V.; Kar, S.; Uysal, A. Karasu; Karavichev, O.; Karavicheva, T.; Karayan, L.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L.D.; Keil, M.; Khan, M. Mohisin; Khan, P.M.; Khan, Shfaqat A.; Khanzadeev, A.; Kharlov, Y.; Khatun, A.; Kileng, B.; Kim, D. W.; Kim, D. J.; Kim, D.-S.; Kim, H.; Kim, J. S.; Kim, J.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C; Klein, J.; Klein-Bösing, C.; Klewin, S.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kopcik, M.; Kour, M.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.L.; Meethaleveedu, G. Koyithatta; Králik, I.; Kravcáková, A.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kucera, V.; Kuhn, C.; Kuijer, P. G.; Kumar, A.; Kumar, J.; Kumar, L.; Kumar, S.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; De Guevara, P. Ladron; Fernandes, C. Lagana; Lakomov, I.; Langoy, R.; Lapidus, K.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lea, R.; Leardini, L.; Lee, S.; Lehas, F.; Strunz-Lehner, Christine; Lemmon, R. C.; Lenti, V.; Leogrande, E.; Monzón, I. León; Vargas, H. León; Leoncino, M.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Lopez, X.; Torres, E. López; Lowe, A.; Luettig, P.; Lunardon, M.; Luparello, G.; Lupi, M.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Cervantes, I. Maldonado; Malinina, L.; Mal'kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, Alicia; Markert, C.; Marquard, M.; Martin, N. A.; Martinengo, P.; Martínez, Isabel M.; García, G. Martínez; Pedreira, M. Martinez; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Mastroserio, A.; Matyja, A.; mayer, C.; Mazer, J.; Mazzilli, M.; Mazzoni, M. A.; McDonald, D.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Pérez, J. Mercado; Meres, M.; Mhlanga, S.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Mishra, T.; Miskowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Zetina, L. Montaño; Montes, E.; De Godoy, D. A Moreira; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Münning, K.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Naik, B.; Nair, Rajiv; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Da Luz, Natal H.; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; De Oliveira, R. A.Negrao; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Ohlson, A.; Okatan, A.; Okubo, T.; Oleniacz, J.; Da Silva, A. C.Oliveira; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Oravec, M.; Velasquez, A. Ortiz; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pagano, D.; Pagano, P.; Paic, G.; Pal, S. K.; Palni, P.; Pan, J.; Pandey, A. K.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, J.-W.; Parmar, S.; Passfeld, A.; Paticchio, V.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.; Peng, X.; Da Costa, H. Pereira; Peresunko, D.; Lezama, E. Perez; Peskov, V.; Pestov, Y.; Petrácek, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Paoskon, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L M; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Poppenborg, H.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Raniwala, R.; Raniwala, S.; Räsänen, S.; Rascanu, B. T.; Rathee, D.; Ravasenga, I.; Read, K. F.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Cahuantzi, M. Rodríguez; Manso, A. Rodriguez; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Montero, A. J Rubio; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Saarinen, S.; Sadhu, S.; Sadovsky, S.; Safarík, K.; Sahlmuller, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Šándor, L.; Sandoval, A.; Sano, M.; Sarkar, D.; Sarkar, N.; Sarma, P.; Scapparone, E.; Scarlassara, F.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schmidt, M.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Šefcík, M.; Seger, J. E.; Sekiguchi, Y.; Sekihata, D.; Selyuzhenkov, I.; Senosi, K.; Senyukov, S.; Serradilla, E.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, M.; Sharma, M.; Sharma, N.; Sheikh, A. I.; Shigaki, K.; Shou, Q. Y.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R; Singhal, V.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J.M.; Snellman, T. W.; Song, J.; Song, M.; Song, Z.; Soramel, F.; Sorensen, S.; Sozzi, F.; Spiriti, E.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Stachel, J.; Stan, I.; Stankus, P.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A P; Sugitate, T.; Suire, C.; Suleymanov, M.; Suljic, M.; Sultanov, R.; Šumbera, M.; Sumowidagdo, S.; Swain, S.; Szabo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Tabassam, U.; Takahashi, J.; Tambave, G. J.; Tanaka, N.; Tarhini, M.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Muñoz, G. Tejeda; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thäder, J.; Thakur, D.; Thomas, D.; Tieulent, R.; Tikhonov, A.; Timmins, A. R.; Toia, A.; Trogolo, S.; Trombetta, G.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vala, M.; Palomo, L. Valencia; Van Der Maarel, J.; Van Hoorne, J. W.; van Leeuwen, Marco; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Doce, O. Vázquez; Vechernin, V.; Veen, A. M.; Velure, A.; Vercellin, E.; Limón, S. Vergara; Vernet, R.; Vickovic, L.; Viinikainen, J.; Vilakazi, Z.; Baillie, O. Villalobos; Tello, A. Villatoro; Vinogradov, A.; Vinogradov, L.; Virgili, T.; Vislavicius, V.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Watanabe, D.; Watanabe, Y.; Weber, M.; Weber, S. G.; Weiser, D. F.; Wessels, J. P.; Westerho, U.; Whitehead, A. M.; Wiechula, J.; Wikne, J.; Wilk, G.; Wilkinson, J.; Willems, G. A.; Williams, M. C S; Windelband, B.; Winn, M.; Yalcin, S.; Yang, P.; Yano, S.; Yin, Z.; Yokoyama, H.; Yoo, I. K.; Yoon, J. H.; Yurchenko, V.; Zaborowska, A.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zardoshti, N.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhang, C.; Zhang, Z.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zyzak, M.
2017-01-01
At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark-gluon plasma (QGP). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei
Substructure of Highly Boosted Massive Jets
Energy Technology Data Exchange (ETDEWEB)
Alon, Raz [Weizmann Inst. of Science, Rehovot (Israel)
2012-10-01
Modern particle accelerators enable researchers to study new high energy frontiers which have never been explored before. This realm opens possibilities to further examine known fields such as Quantum Chromodynamics. In addition, it allows searching for new physics and setting new limits on the existence of such. This study examined the substructure of highly boosted massive jets measured by the CDF II detector. Events from 1.96 TeV proton-antiproton collisions at the Fermilab Tevatron Collider were collected out of a total integrated luminosity of 5.95 fb$^{-1}$. They were selected to have at least one jet with transverse momentum above 400 GeV/c. The jet mass, angularity, and planar flow were measured and compared with predictions of perturbative Quantum Chromodynamics, and were found to be consistent with the theory. A search for boosted top quarks was conducted and resulted in an upper limit on the production cross section of such top quarks.
Nuclear Theory Group, University of Washington recent and planned research
International Nuclear Information System (INIS)
1993-01-01
The work of the five staff members is presented individually in turn. (1) Nonperturbative aspects of quantum chromodynamics and its implication for phenomena involving nucleon structure, nuclear structure, and relativistic heavy-ion collisions. (2) Symmetries and the connection of the quark-gluon description of nucleons and nuclei with the nucleon-meson degrees of freedom-parity nonconservation, time reversal invariance, chiral symmetry and charge symmetry, QCD sum rules. (3) The relation between nuclear physics and quantum chromodynamics-physics of color transparency, fundamental symmetries, physics of confinement and hadronic form factors, EMC effect. (4) Chirally invariant chromo-dielectric soliton model, many-nucleon system in models of QCD, flux tube dynamics, anti p-p to anti Λ-Λ and anti Λ-Σ collisions, isotopic effects in atomic parity nonconservation, quantum molecular dynamics. (5) Numerical work related to lattice QCD simulations, and analytical work related to model studies of hadronic phenomenology and the development and understanding of new methods
$\\mathrm{\\Lambda_{c}^{+}}$ baryon production measurements with the ALICE experiment at the LHC
AUTHOR|(INSPIRE)INSPIRE-00416828; Dainton, John; Lemmon, Roy
Quantum chromodynamics, the quantum field theory that describes the strong interaction, demonstrates a property known as asymptotic freedom which weakens the strong coupling constant $\\alpha_s$ at high energies or short distances. The measurement of particles containing heavy quarks, i.e. charm and beauty, in high-energy particle collisions is a stringent test of the theory of quantum chromodynamics in the regime where $\\alpha_s$ is small. In addition, asymptotic freedom leads to a phase transition of nuclear matter at high temperatures or energy densities to a phase known as the Quark-Gluon Plasma, where quarks and gluons are deconfined, and this state of matter can be studied in relativistic heavy-ion collisions. Particles containing heavy quarks, i.e. charm and beauty, have been proposed as probes of the properties of the Quark Gluon Plasma, where the measurement of mesons and baryons can offer insight into the transport properties of the medium and mechanisms related to the formation of hadrons during the...
The BlueGene/L Supercomputer and Quantum ChromoDynamics
International Nuclear Information System (INIS)
Vranas, P; Soltz, R
2006-01-01
In summary our update contains: (1) Perfect speedup sustaining 19.3% of peak for the Wilson D D-slash Dirac operator. (2) Measurements of the full Conjugate Gradient (CG) inverter that inverts the Dirac operator. The CG inverter contains two global sums over the entire machine. Nevertheless, our measurements retain perfect speedup scaling demonstrating the robustness of our methods. (3) We ran on the largest BG/L system, the LLNL 64 rack BG/L supercomputer, and obtained a sustained speed of 59.1 TFlops. Furthermore, the speedup scaling of the Dirac operator and of the CG inverter are perfect all the way up to the full size of the machine, 131,072 cores (please see Figure II). The local lattice is rather small (4 x 4 x 4 x 16) while the total lattice has been a lattice QCD vision for thermodynamic studies (a total of 128 x 128 x 256 x 32 lattice sites). This speed is about five times larger compared to the speed we quoted in our submission. As we have pointed out in our paper QCD is notoriously sensitive to network and memory latencies, has a relatively high communication to computation ratio which can not be overlapped in BGL in virtual node mode, and as an application is in a class of its own. The above results are thrilling to us and a 30 year long dream for lattice QCD
Precision tests of quantum chromodynamics and the standard model
International Nuclear Information System (INIS)
Brodsky, S.J.; Lu, H.J.
1995-06-01
The authors discuss three topics relevant to testing the Standard Model to high precision: commensurate scale relations, which relate observables to each other in perturbation theory without renormalization scale or scheme ambiguity, the relationship of compositeness to anomalous moments, and new methods for measuring the anomalous magnetic and quadrupole moments of the W and Z
Processes with large Psub(T) in the quantum chromodynamics
International Nuclear Information System (INIS)
Slepchenko, L.A.
1981-01-01
Necessary data on deep inelastic processes and processes of hard collision of hadrons and their interpretation in QCD are stated. Low of power reduction of exclusive and inclusive cross sections at large transverse momenta, electromagnetic and inelastic (structural functions) formfactors of hadrons have been discussed. When searching for a method of taking account of QCD effects scaling disturbance was considered. It is shown that for the large transverse momenta the deep inelastic l-h scatterina is represented as the scattering with a compound system (hadron) in the pulse approximation. In an assumption of a parton model obtained was a hadron cross section calculated through a renormalized structural parton function was obtained. Proof of the factorization in the principal logarithmic approximation of QCD has been obtained by means of a quark-gluon diagram technique. The cross section of the hadron reaction in the factorized form, which is analogous to the l-h scattering, has been calculated. It is shown that a) the diagram summing with the gluon emission generates the scaling disturbance in renormalized structural functions (SF) of quarks and gluons and a running coupling constant arises simultaneously; b) the disturbance character of the Bjorken scaling of SF is the same as in the deep inelasic lepton scattering. QCD problems which can not be solved within the framework of the perturbation theory, are discussed. The evolution of SF describing the bound state of a hadron and the hadron light cone have been studied. Radiation corrections arising in two-loop and higher approximations have been evaluated. QCD corrections for point-similar power asymptotes of processes with high energies and transfers of momenta have been studied on the example of the inclusive production of quark and gluon jets. Rules of the quark counting of anomalous dimensionalities of QCD have been obtained. It is concluded that the considered limit of the inclusive cross sections is close to conditions of cosmic ray experiments at psub(T) [ru
Quantum Chromodynamics and nuclear physics at extreme energy density
International Nuclear Information System (INIS)
Mueller, B.
1993-01-01
This report discusses research in the following topics: Hadron structure physics; relativistic heavy ion collisions; finite- temperature QCD; real-time lattice gauge theory; and studies in quantum field theory
The Conformal Template and New Perspectives for Quantum Chromodynamics
International Nuclear Information System (INIS)
Brodsky, Stanley J.
2007-01-01
Conformal symmetry provides a systematic approximation to QCD in both its perturbative and nonperturbative domains. One can use the AdS/CFT correspondence between Anti-de Sitter space and conformal gauge theories to obtain an analytically tractable approximation to QCD in the regime where the QCD coupling is large and constant. For example, there is an exact correspondence between the fifth-dimensional coordinate of AdS space and a specific impact variable which measures the separation of the quark constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions of mesons and baryons, the fundamental entities which encode hadron properties and allow the computation of exclusive scattering amplitudes. One can also use conformal symmetry as a template for perturbative QCD predictions where the effects of the nonzero beta function can be systematically included in the scale of the QCD coupling. This leads to fixing of the renormalization scale and commensurate scale relations which relate observables without scale or scheme ambiguity. The results are consistent with the renormalization group and the analytic connection of QCD to Abelian theory at N C → 0. I also discuss a number of novel phenomenological features of QCD. Initial- and .nal-state interactions from gluon-exchange, normally neglected in the parton model, have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, di.ractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss tests of hidden color in nuclear wavefunctions, the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency, nonperturbative antisymmetric sea quark distributions, anomalous heavy quark e.ects, and the unexpected effects of direct higher-twist processes
The Conformal Template and New Perspectives for Quantum Chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J.; /SLAC
2007-03-06
Conformal symmetry provides a systematic approximation to QCD in both its perturbative and nonperturbative domains. One can use the AdS/CFT correspondence between Anti-de Sitter space and conformal gauge theories to obtain an analytically tractable approximation to QCD in the regime where the QCD coupling is large and constant. For example, there is an exact correspondence between the fifth-dimensional coordinate of AdS space and a specific impact variable which measures the separation of the quark constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions of mesons and baryons, the fundamental entities which encode hadron properties and allow the computation of exclusive scattering amplitudes. One can also use conformal symmetry as a template for perturbative QCD predictions where the effects of the nonzero beta function can be systematically included in the scale of the QCD coupling. This leads to fixing of the renormalization scale and commensurate scale relations which relate observables without scale or scheme ambiguity. The results are consistent with the renormalization group and the analytic connection of QCD to Abelian theory at N{sub C} {yields} 0. I also discuss a number of novel phenomenological features of QCD. Initial- and .nal-state interactions from gluon-exchange, normally neglected in the parton model, have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, di.ractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss tests of hidden color in nuclear wavefunctions, the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency, nonperturbative antisymmetric sea quark distributions, anomalous heavy quark e.ects, and the unexpected effects of direct higher-twist processes.
A statistical model of structure functions and quantum chromodynamics
International Nuclear Information System (INIS)
Mac, E.; Ugaz, E.; Universidad Nacional de Ingenieria, Lima
1989-01-01
We consider a model for the x-dependence of the quark distributions in the proton. Within the context of simple statistical assumptions, we obtain the parton densities in the infinite momentum frame. In a second step lowest order QCD corrections are incorporated to these distributions. Crude, but reasonable, agreement with experiment is found for the F 2 , valence and q, anti q distributions for x> or approx.0.2. (orig.)
Numerical calculation of hadron masses in lattice quantum chromodynamics
International Nuclear Information System (INIS)
Montvay, I.
1985-07-01
Recent numerical Monte Carlo simulations of the hadron spectrum are reviewed. After a general introduction, different ways of calculating the hadron masses in the ''quenched approximation'' (i.e. neglecting virtual quark loops) are described and the latest results are summarized. The pseudofermion method and the iterative hopping expansion method for the introduction of dynamical quarks is discussed, and the first results about the hadron spectrum including the effect of virtual quark loops are reviewed. A separate section is devoted to the discussion of the questions related to scaling with dynamical quarks. (orig./HSI)
Unusual initial and final state effects in quantum chromodynamics
International Nuclear Information System (INIS)
Nelson, C.A.
1990-12-01
We have constructed fundamental test which can be used to probe discrete symmetries, and their possible violations, in the required ''new physics'' beyond the standard model. In a recent paper for applications at an e + e - collider, we have proposed a simple test for ''maximal P -- maximal C'' violation in the Z degree → τ 1 - τ 1 + coupling. For τ minus-plus → π minus-plus ν, for example, this test is based on an azimuthal correlation function I(φ e , φ) where the azimuthal angles are defined relative to the final π 1 - . For e - e + collisions in the Γ or J/Ψ regions, I(φ e , φ) can be used to test for a complex phase in the γ* → τ - τ + coupling. In other research programs, we are continuing to investigate our proposal that partons be identified with nearly degenerate, coherent quark-gluon ''jet'' states, and have proven a completeness relation for the q-analogue of the unusual coherent states
The critical point of quantum chromodynamics through lattice and ...
Indian Academy of Sciences (India)
The Padé approximants are the rational functions. PL. M (z) = .... Deviations from a smooth behaviour near the critical point are visible in these extrap- ... see that there is evidence, albeit statistically not very significant, that the kurtosis changes.
Form factors and charge radii in a quantum chromodynamics ...
Indian Academy of Sciences (India)
... parent compared to the linear parent. Also, the analysis leads to a lower as well as upper bounds on the four-momentum transfer 2, hinting at a workable range of 2 within this approach, which may be useful in future experimental analyses. Comparison of both the options shows that the linear parent is the better option.
Equation of motion for string operators in quantum chromodynamics
International Nuclear Information System (INIS)
Suura, H.
1979-04-01
I derive from the QCD Lagrangian differential laws describing motions and interactions of an infinite set of string operators - locally gaugeinvariant color-singlet operators. By truncating the set, I obtain a q-anti q wave equation with a confinement potential, and also a jet-fragmentation equation which describes splitting of a q-anti q string and creation of I = O vector mesons. I argue for the validity of the perturbative treatment of the string operators. (orig.) [de
Bag-model quantum chromodynamics for hyperons at low energy
International Nuclear Information System (INIS)
Weber, H.J.; Maslow, J.N.
1980-01-01
In a non-perturbative bag model framework, gluon exchange which mediates quark exchange scattering in conjunction with quark interchange is shown to be the basis of the OBE interactions of hyperons at low energy. (orig.)
Tests of perturbative quantum chromodynamics in photon-photon collisions
International Nuclear Information System (INIS)
Brodsky, S.J.
1979-01-01
The production of hadrons in the collision of two photons via the process e + e - → e + e - X can provide an ideal laboratory for testing many of the features of the photon's hadronic interactions, especially its short-distance aspects. That part of two-photon physics which is particularly relevant to tests of perturbative QCD is reviewed here. 6 figures
Form factors and charge radii in a quantum chromodynamics ...
Indian Academy of Sciences (India)
Author Affiliations. Bhaskar Jyoti Hazarika1 D K choudhury1 2. Centre for Theoretical Studies, Pandu College, Guwahati 781 012, India; Department of Physics, Gauhati University, Guwahati 781 014, India ...
Quantum Theory of Fields. Progress Report
International Nuclear Information System (INIS)
Gupta, S. N.
1996-01-01
During the period covered by this progress report, they have published the following three research papers: (1) B c spectroscopy in a quantum-chromodynamic potential model; (2) Gauge-boson scattering signals at the CERN LHC; and (3) Relativistic two-photon and two-gluon decay rates of heavy quarkonia
International Nuclear Information System (INIS)
Taylor, J.C.
1983-01-01
The author introduces quantum chromodynamics as a SU(3)-Yang-Mills theory describing the interactions between the quarks. After a general introduction the Feynman rules are discussed. Then the Ward identity is considered. Thereafter the renormalization is described. Finally the beta function and asymptotic freedom are considered. (HSI)
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.).
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Penc, Ondřej; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2016-01-01
Roč. 76, č. 5 (2016), s. 1-61, č. článku 291. ISSN 1434-6044 Institutional support: RVO:68378271 Keywords : ATLAS * quantum chromodynamics * perturbation theory * Drell-Yan process * CERN LHC Coll Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.331, year: 2016
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Penc, Ondřej; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2016-01-01
Roč. 2016, č. 8 (2016), s. 1-61, č. článku 104. ISSN 1029-8479 Institutional support: RVO:68378271 Keywords : hadron-hadron scattering * ATLAS * quantum chromodynamics * perturbation theory * CERN LHC Coll Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 6.063, year: 2016
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Böhm, Jan; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Penc, Ondřej; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2016-01-01
Roč. 93, č. 3 (2016), s. 1-28, č. článku 034914. ISSN 2469-9985 Institutional support: RVO:68378271 Keywords : ATLAS * transverse momentum dependence * quantum chromodynamics * perturbation theory * CERN LHC Coll Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.820, year: 2016
Quark-gluon plasma: Status of heavy ion physics
Indian Academy of Sciences (India)
Lattice quantum chromodynamics (QCD), defined on a discrete space–time lattice, leads to a spectacular non-perturbative prediction of a new state of matter, called quark-gluon plasma (QGP), at sufficiently high temperatures or equivalently large energy densities. The experimental programs of CERN, Geneva and BNL, ...
Analytic continuation and perturbative expansions in QCD
Czech Academy of Sciences Publication Activity Database
Caprini, I.; Fischer, Jan
2002-01-01
Roč. 24, - (2002), s. 127-135 ISSN 1434-6044 R&D Projects: GA MPO RP-4210/69 Institutional research plan: CEZ:AV0Z1010920 Keywords : perturbative expansion * quantum chromodynamics * infrared ambiguity * essential singularities Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 6.162, year: 2002
Brookhaven: Spin result underlined
Energy Technology Data Exchange (ETDEWEB)
Anon.
1990-09-15
A recent experiment looking at violent proton-proton elastic scattering confirms, with high precision, earlier data which puzzled many theorists. Most pictures of strong interactions based on perturbative quark-gluon field theory (Quantum Chromodynamics, QCD) suggested that spin effects should disappear with energy and as the collisions become more violent.
Technicolor Higgs boson in the light of LHC data
DEFF Research Database (Denmark)
Belyaev, Alexander; S. Brown, Matthew; Foadi, Roshan
2014-01-01
We consider scenarios in which the 125 GeV resonance observed at the Large Hadron Collider is a Technicolor (TC) isosinglet scalar, the TC Higgs. By comparison with quantum chromodynamics, we argue that the couplings of the TC Higgs to the massive weak bosons are very close to the Standard Model...
Anisotropic Flow and flow fluctuations at the Large Hadron Collider
Zhou, Y.
2016-01-01
One of the fundamental questions in the phenomenology of Quantum Chromodynamics (QCD) is what the properties of matter are at the extreme densities and temperatures where quarks and gluons are in a new state of matter, the so-called Quark Gluon Plasma (QGP). Collisions of high-energy heavy-ions at
Summing logs: the saga continues...
International Nuclear Information System (INIS)
Ellis, S.D.
1982-01-01
The structure of perturbative Quantum Chromodynamics in kinematic regimes characterized by two large but very different mass scales is discussed. The status of the sequence of approximations employed to theoretically study these regimes is reviewed along with some discussion of the present phenomenology. Various important outstanding questions are noted. 22 references
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
Theoretical high energy physics: Progress report, May 1, 1987-April 30, 1988
International Nuclear Information System (INIS)
Lee, T.D.
1988-05-01
This paper discusses the progress on High Energy Physics projects by the facility of Columbia University. Short discussions are given on the use of parallel computers for numerical simulation of lattice quantum chromodynamics; Soliton condensation; High Temperature superconductivity; New calculations techniques for non-Abelian gauge theories and other related topics
Accurate conjugate gradient methods for families of shifted systems
Eshof, J. van den; Sleijpen, G.L.G.
2003-01-01
We consider the solution of the linear system (ATA + σI)xσ = ATb, for various real values of σ. This family of shifted systems arises, for example, in Tikhonov regularization and computations in lattice quantum chromodynamics. For each single shift σ this system can be solved using the conjugate
Pulse pile-up recovery for the front-end electronics of the PANDA Electromagnetic Calorimeter
Tambave, G.; Kavatsyuk, M.; Guliyev, E.; Schreuder, F.; Moeini, H.; Löhner, H.
2012-01-01
At the future Facility for Antiproton and Ion Research near Darmstadt in Germany the PANDA detector will be employed to study the charmonium spectrum and to search for narrow exotic hadronic states, predicted by Quantum Chromodynamics. In the PANDA experiment, 1.5 to 15GeV/c anti-protons will
2012 European School of High-Energy Physics
Mulders, M; ESHEP 2012
2014-01-01
The European School of High-Energy Physics is intended to give young physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lecture notes on the Standard Model of electroweak interactions, quantum chromodynamics, flavour physics, physics beyond the Standard Model, neutrino physics, and cosmology.
Quantization of physical parameters
International Nuclear Information System (INIS)
Jackiw, R.; Massachusetts Inst. of Tech., Cambridge; Massachusetts Inst. of Tech., Cambridge
1984-01-01
Dynamical models are described with parameters (mass, coupling strengths) which must be quantized for quantum mechanical consistency. These and related topological ideas have physical application to phenomenological descriptions of high temperature and low energy quantum chromodynamics, to the nonrelativistic dynamics of magnetic monopoles, and to the quantum Hall effect. (author)
Pulse pile-up recovery for the front-end electronics of the PANDA Electromagnetic Calorimeter
Tambave, G.; Kavatsyuk, M.; Guliyev, E.; Schreuder, F.; Moeini, H.; Löhner, H.
At the future Facility for Antiproton and Ion Research near Darmstadt in Germany the PANDA detector will be employed to study the charmonium spectrum and to search for narrow exotic hadronic states, predicted by Quantum Chromodynamics. In the PANDA experiment, 1.5 to 15GeV/c anti-protons will
Pulse pile-up recovery for the front-end electronics of the PANDA Electromagnetic Calorimeter
Tambave, G.; Guliyev, E.; Kavatsyuk, M.; Schreuder, F.; Löhner, H.
2011-01-01
To study the Charmonium spectrum and search for narrow exotic hadronic states, predicted by Quantum Chromodynamics, the PANDA detector will be employed at the future Facility for Antiproton and Ion Research near Darmstadt in Germany. In the PANDA experiment, 1.5 to 15 GeV/c anti-protons will collide
Czech Academy of Sciences Publication Activity Database
Abazov, V. M.; Abbott, B.; Acharya, B.S.; Kupčo, Alexander; Lokajíček, Miloš
2015-01-01
Roč. 91, č. 3 (2015), "032007-1"-"032007-26" ISSN 1550-7998 Institutional support: RVO:68378271 Keywords : D0 * quantum chromodynamics * Batavia TEVATRON Coll * p anti-p --> W * W --> electron neutrino * 1960 GeV-cms Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014
International Nuclear Information System (INIS)
Glashow, S.L.
1979-01-01
The author states his views regarding the importance of the experiments made possible if LEP is built. The main contribution of the LEP will be to understanding the physics of leptons, quarks and quantum chromodynamics. The author suggests the directions in which the new results might lead. (W.D.L.)
International Nuclear Information System (INIS)
Povinec, Pavel
1991-01-01
With the Standard Model of particle physics currently looking impregnable, physicists are eager to look inside it to see what makes it work. The Standard Model uses the electroweak synthesis of electromagnetism and the weak nuclear force, loosely coupled with quantum chromodynamics - QCD - the contender field theory of quark interactions
International Nuclear Information System (INIS)
Gross, F.; Williamson, C.
1987-10-01
This report contains papers from the CEBAF accelerator facility summer workshop. Some topics covered are: baryon-baryon interactions, deuteron form factors; neutron detection; high resolution spectrometers; nuclear strangeness; parity violation; photon-deuteron interactions; chemical reactions in ion sources; quantum chromodynamics; hypernuclear magnetic moments; and photoproduction of π + from 14 N
Spin-polarized versus chiral condensate in quark matter at finite temperature and density
DEFF Research Database (Denmark)
Matsuoka, Hiroaki; Tsue, Yasuhiko; da Providencia, Joao
2016-01-01
It is shown that the spin-polarized condensate appears in quark matter at high baryon density and low temperature due to the tensor-type four-point interaction in the Nambu-Jona-Lasiniotype model as a low-energy effective theory of quantum chromodynamics. It is indicated within this low-energy ef...
Brookhaven: Spin result underlined
International Nuclear Information System (INIS)
Anon.
1990-01-01
A recent experiment looking at violent proton-proton elastic scattering confirms, with high precision, earlier data which puzzled many theorists. Most pictures of strong interactions based on perturbative quark-gluon field theory (Quantum Chromodynamics, QCD) suggested that spin effects should disappear with energy and as the collisions become more violent
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics. D K CHOUDHURY. Articles written in Pramana – Journal of Physics. Volume 87 Issue 4 October 2016 pp 52 Regular. Root mean square radii of heavy flavoured mesons in a quantum chromodynamics potential model · D K CHOUDHURY TAPASHI DAS · More Details ...
Pole masses of quarks in dimensional reduction
International Nuclear Information System (INIS)
Avdeev, L.V.; Kalmykov, M.Yu.
1997-01-01
Pole masses of quarks in quantum chromodynamics are calculated to the two-loop order in the framework of the regularization by dimensional reduction. For the diagram with a light quark loop, the non-Euclidean asymptotic expansion is constructed with the external momentum on the mass shell of a heavy quark
Numerical study of the lattice meson form factor
International Nuclear Information System (INIS)
Woloshyn, R.M.; Kobos, A.M.
1986-01-01
The electric form factor of the pseudo-Goldstone meson (the generic pion) is calculated in quenched lattice quantum chromodynamics with SU(2) color. Charge radii are calculated for different values of the bare-quark mass. The results are in agreement with the physically reasonable expectation that heavier quarks have distributions of smaller radius
The problem of electric sources in Einstein's Hermite-symmetric field theory
International Nuclear Information System (INIS)
Kreisel, E.
1986-01-01
The possibility is investigated to introduce a geometric source without A-invariance and Hermite-symmetry breaking of Einstein's Hermitian relativity. It would be very meaningful to interpret a source of this kind as electric current. With this extension Einstein's unitary field theory contains Einstein's gravitation, electromagnetism and the gluonic vacuum of chromodynamics. (author)
Parity violation workshop: CEBAF [Continuous Electron Beam Accelerator Facility
International Nuclear Information System (INIS)
Walecka, J.D.
1986-01-01
This paper discusses the use of electron scattering experiments for exploring parity violation in the nuclear domain. It is shown how such experiments can test the structure of strong interactions, the local gauge theory quantum chromodynamics based on color, and the unified gauge theory of electroweak interactions. 14 refs., 13 figs., 1 tab
Kvarky s barvou a vůní a co dál?
Czech Academy of Sciences Publication Activity Database
Chýla, Jiří
2006-01-01
Roč. 100, č. 12 (2006), s. 1055-1067 ISSN 0009-2770 R&D Projects: GA MŠk LC527 Institutional research plan: CEZ:AV0Z10100502 Keywords : standard model * quarks * leptons * quantum chromodynamics * supersymmetry * strings Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 0.431, year: 2006
Two-loop matching coefficients for heavy quark currents
International Nuclear Information System (INIS)
Kniehl, B.A.; Onishchenko, A.; Petersburg Nuclear Physics Institute, Gatchina; Piclum, J.H.; Karlsruhe Univ.; Steinhauser, M.
2006-04-01
In this paper we consider the matching coefficients up to two loops between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) for the vector, axial-vector, scalar and pseudo-scalar currents. The structure of the effective theory is discussed and analytical results are presented. Particular emphasis is put on the singlet diagrams. (Orig.)
Squeezed colour states in gluon jet
Kilin, S. YA.; Kuvshinov, V. I.; Firago, S. A.
1993-01-01
The possibility of the formation of squeezed states of gluon fields in quantum chromodynamics due to nonlinear nonperturbative self interaction during jet evolution in the process of e(+)e(-) annihilation into hadrons, which are analogous to the quantum photon squeezed states in quantum electrodynamics, is demonstrated. Additionally, the squeezing parameters are calculated.
Indian Academy of Sciences (India)
473–480. Erratum to: An integral transform of Green's function, off-shell Jost solution and. T-matrix for ... Study of neutron-rich Mo isotopes by the projected shell model approach ... 695–704. Net-proton measurements at RHIC and the quantum chromodynamics phase diagram ... 729–737. Electron scattering for exotic nuclei.
International Nuclear Information System (INIS)
Radyushkin, A.V.; Slepchenko, L.A.
1983-01-01
Analysis of experimental status of quantum chromodynamics (QCD) has been carried out. A short introduction into QCD is given. QCD sum rules are considered. Jets in e + e - annihilation and inclusive processes of lepton-hadron and hadron-hadron scattering are considered. Effect of QCD corrections to perturbation theory on quark count is analyzed
[Theoretical studies in high energy physics]: Final technical report
International Nuclear Information System (INIS)
Braaten, E.
1988-01-01
The research activities that were supported by this grant were focused primarily on low energy quantum chromodynamics. Significant progress was made in the Skyrme model for baryons, string models for color flux tubes, hadronic decays of the /tau/ lepton, technicolor models of the electroweak interactions, and meson form factors in perturbative QCD
Chiral symmetry in perturbative QCD
International Nuclear Information System (INIS)
Trueman, T.L.
1979-04-01
The chiral symmetry of quantum chromodynamics with massless quarks is unbroken in perturbation theory. Dimensional regularization is used. The ratio of the vector and axial vector renormalization constante is shown to be independent of the renormalization mass. The general results are explicitly verified to fourth order in g, the QCD coupling constant
Czech Academy of Sciences Publication Activity Database
Caprini, I.; Fischer, Jan
2011-01-01
Roč. 84, č. 5 (2011), 054019/1-054019/15 ISSN 1550-7998 R&D Projects: GA MŠk LA08015 Institutional research plan: CEZ:AV0Z10100502 Keywords : quantum chromodynamics, * conformal mapping * tau lepton decay Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.558, year: 2011
Czech Academy of Sciences Publication Activity Database
Aaltonen, T.; Abazov, V. M.; Abbott, B.; Kupčo, Alexander; Lokajíček, Miloš; Lysák, Roman
2014-01-01
Roč. 89, č. 7 (2014), "072001-1"-"072001-16" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG12006 Institutional support: RVO:68378271 Keywords : Batavia TEVATRON Coll * quantum chromodynamics * perturbation theory * statistical analysis * CDF * DZERO Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Böhm, Jan; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Myška, M.; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2014-01-01
Roč. 2014, č. 9 (2014), s. 1-55 ISSN 1029-8479 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : rapidity * ATLAS * differential cross section * quantum chromodynamics * CERN LHC Coll * Monte Carlo Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 6.111, year: 2014
Quark sea and the. delta. I=1/2 rule
Energy Technology Data Exchange (ETDEWEB)
Donoghue, J F [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics; Golowich, E [Massachusetts Univ., Amherst (USA)
1977-08-29
The effect on nonleptonic processes of quark-antiquark pairs due to quantum chromodynamics is studied. Their presence improves agreement between theory and experiment for hyperon decays. In kaon decays a new ..delta..I=1/2 contribution is found, but ..delta..I=3/2 effects are still too large to be in agreement.
International Nuclear Information System (INIS)
Collins, J.C.
1985-01-01
Progress in quantum chromodynamics in the past year is reviewed in these specific areas: proof of factorization for hadron-hadron collisions, fast calculation of higher order graphs, perturbative Monte Carlo calculations for hadron-hadron scattering, applicability of perturbative methods to heavy quark production, and understanding of the small-x problem. 22 refs
International Nuclear Information System (INIS)
Scharre, D.L.
1982-01-01
It is expected from quantum chromodynamics (QCD) that glueballs, bound states which contain gluons but no valence quarks, should exist. To date, no conclusive evidence for glueballs has been presented. After a brief review of the expected properties and experimental signatures of glueballs the status of some glueball candidate states are discussed
Tests of Local Position Invariance Using Continuously Running Atomic Clocks
2013-01-22
of the difference in anomalous redshift parameters, β = β1 − β2. (a) Dark data points are previous measurements: (i) neutral strontium optical...and the ratio of the light quark mass to the quantum chromodynamics length scale, mq/ QCD, where mq is the average of the up and down quark masses [17
QCD analysis of jets in e/sup +/e/sup -/ annihilation
Energy Technology Data Exchange (ETDEWEB)
Ali, A
1980-10-01
Jets in e/sup +/e/sup -/ annihilation are discussed in the context of perturbative Quantum Chromodynamics. Topics discussed include higher twist contribution, effects of quark masses and fragmentation on the 3 and 4 jet rates and some distributions bearing on the experimental verification of 4 jet events at the PETRA/PEP energies.
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Böhm, Jan; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2014-01-01
Roč. 10, Oct (2014), 1-49 ISSN 1029-8479 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : quantum chromodynamics * perturbation the ory * higher-order 1 * rapidity * ATLAS * CERN LHC Coll * electron Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 6.111, year: 2014
International Nuclear Information System (INIS)
Veltman, M.
1979-01-01
The theory of strong interactions is supposedly quantum chromodynamics, an unbroken gauge theory based on the group SU(3). The theory of weak and e.m. interactions is believed to be described by the Weinberg-GIM model, based on the spontaneously broken symmetry SU(2) x U(1). There are many uncertainties around these theories. Quantum chromodynamics has met with many successes, but the most important feature, quark confinement, has not been proven. Also other things, such as PCAC, have not yet been understood. And we have no reasonable calculation of particle masses (pion, proton, etc.). Nevertheless we consider quantum chromodynamics a reasonably respectable theory, and in this talk we will take that theory for granted. The situation with respect to the SU(2) x U(1) theory is much more difficult. No vector bosons have yet been observed, and the Higgs system is more obscure than ever. Glashow's model has been turned into a renormalizable model by Weinberg through the use of the Higgs system, but up to now no radiative corrections of the appropriate type have been measured. The only thing we know is that at low energies this Glashow model reduces to a four-fermion theory involving certain currents, and this has been checked reasonably well. Also, the discovery of charm (and hopefully the discovery of a top quark) fits beautifully into the picture along the lines of the GIM mechanism. CP violation could be due to complex quark masses according to the Kobayashi-Maskawa scheme. The point of view is taken that the existence of vector bosons is not evident, and the Higgs mechanism is a possibility at best. It is the purpose of this talk to outline and clarify this view
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Penc, Ondřej; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2015-01-01
Roč. 750, Nov (2015), s. 427-447 ISSN 0370-2693 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : ATLAS * quantum chromodynamics * perturbation theory * precision measurement * correlation function * momentum transfer * CERN LHC Coll Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.787, year: 2015
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Gallus, Petr; Gunther, Jaroslav; Jakoubek, Tomáš; Juránek, Vojtěch; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Růžička, Pavel; Schovancová, Jaroslava; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Tic, Tomáš; Valenta, J.; Vrba, Václav
2013-01-01
Roč. 73, č. 8 (2013), s. 1-56 ISSN 1434-6044 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : ATLAS * CERN * higher-order jet * rapidity * quantum chromodynamics * perturbation theory * parton * distribution function * scattering Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 5.436, year: 2013
International Nuclear Information System (INIS)
Salati, Pierre.
1980-01-01
The purpose of this work is to analyse the structure functions produced by a deep inelastic scattering experiment of muons upon a hadronic target. A non perturbative model is tested. In order to chek the quantum chromodynamics, the moments and the Altarelli-Parisi equations are used. The main result is the scaling parameter lambda [fr
Gauge boson production at colliders – Predictions for precision studies
Indian Academy of Sciences (India)
2012-10-03
Oct 3, 2012 ... Next-to-leading order; quantum chromodynamics; gauge bosons. PACS Nos 12.38.−t; 12.15.−y. 1. .... to-leading logarithms (NNLL), transverse momentum resummation [11] and soft gluon resummation have been ..... From the figure it is clear that if only the three hardest jets are included in the definition of.
Indian Academy of Sciences (India)
Vol. 55, Nos 1 & 2. — journal of. July & August 2000 physics pp. 327–333. Quantum chromodynamics: Working group report. Coordinators: SOURENDU GUPTA. ½ and D INDUMATHI. ¾. Contributors: S Banerjee. ½. , R Basu ..... 97), Jerusalem, Israel, 19–26 Aug. 1997. [18] P Chiappetta, G J Gounaris, J Layssac and F M ...
Recent tests of QCD with the ATLAS detector
Callea, Giuseppe; The ATLAS collaboration
2018-01-01
A summary of the recent ATLAS results in Quantum Chromodynamics is given, covering a number of areas that reflect the work of the collaboration on the Bose-Einstein correlations in multi-particle events, the inclusive jet production, the measurements of jet substructure quantities in di-jet events and the photon-photon scattering exclusive processes.
Czech Academy of Sciences Publication Activity Database
Adamczyk, L.; Agakishiev, G.; Barnovská, Zuzana; Bielčík, J.; Bielčíková, Jana; Chaloupka, P.; Chung, Paul; Kapitán, Jan; Hajková, O.; Pachr, M.; Rusňák, Jan; Šumbera, Michal; Tlustý, David
2012-01-01
Roč. 85, č. 9 (2012), č. článku 092010. ISSN 2470-0010 R&D Projects: GA MŠk LA09013 Institutional support: RVO:61389005 Keywords : leptonic decay * RHIC * quantum chromodynamics Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 4.691, year: 2012
The QCD phase transitions: From mechanism to observables
Energy Technology Data Exchange (ETDEWEB)
Shuryak, E.V.
1997-09-22
This paper contains viewgraphs on quantum chromodynamic phase transformations during heavy ion collisions. Some topics briefly described are: finite T transitions of I molecule pairs; finite density transitions of diquarks polymers; and the softtest point of the equation of state as a source of discontinuous behavior as a function of collision energy or centrality.
Measurements of Jets and αs at HERA
International Nuclear Information System (INIS)
Bunyatyan, Armen
2009-01-01
Jet production in electron-proton scattering at HERA provides an important testing ground for Quantum Chromodynamics and allows improved determinations of the strong coupling, α s . A review of recent measurements of jet cross sections in photoproduction and neutral current DIS (NC DIS) at HERA is presented, and the latest determinations of α s are shown.
Solution of the gauge identities in the axial gauge
International Nuclear Information System (INIS)
Delbourgo, R.
1981-01-01
Starting from the spectral representation of the two-point functions in the axial gauge, the gauge identities are solved so as to express the higher-point Green functions linearly in terms of the two-point spectral function. The four-point functions are an important input for investigations of scalar electrodynamics and vector chromodynamics based on the gauge technique. (author)
First measurement of jet mass in Pb–Pb and p–Pb collisions at the LHC
Acharya, S.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altsybeev, I.; Alves Garcia Prado, C.; Janssen, M M; Andrei, C.; Andrews, H. A.; Andronic, A.; Anguelov, V.; Anson, C. D.; Antičić, T.; Antinori, F.; Antonioli, P.; Anwar, R.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Ball, M.C.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barioglio, L.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.|info:eu-repo/dai/nl/411263188; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Beltran, L. G. E.; Belyaev, V.; Bencedi, G.; Beole, S.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.|info:eu-repo/dai/nl/371577810; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.|info:eu-repo/dai/nl/371578248; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Blair, J. T.; Blau, D.; Blume, C.; Boca, G.; Bock, F.; Bogdanov, A.; Boldizsár, L.; Bombara, M.; Bonomi, G.; Bonora, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buhler, P.; Iga Buitron, S. A.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caffarri, D.; Caines, H.; Caliva, A.|info:eu-repo/dai/nl/411885812; Calvo Villar, E.; Camerini, P.; Capon, A. A.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A R; Ceballos Sanchez, C.; Cerello, P.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Cho, Sukhee; Chochula, P.; Choi, K.; Chojnacki, M.|info:eu-repo/dai/nl/411888056; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Concas, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Costanza, S.; Crkovská, J.; Crochet, P.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; Dasgupta, S. S.; De Caro, A.; De Cataldo, G.; De Conti, C.; De Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Souza, R. Derradi; Degenhardt, H. F.; Deisting, A.; Deloff, A.; Deplano, C.; Dhankher, P.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Di Ruzza, B.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, O.; Dobrin, A.|info:eu-repo/dai/nl/372618715; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.|info:eu-repo/dai/nl/355502488; Ducroux, L.; Duggal, A. K.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erhardt, F.; Espagnon, B.; Esumi, S.; Eulisse, G.; Eum, J.; Evans, D.; Evdokimov, S.; Fabbietti, L.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A S; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; De Francisco, A.; Frankenfeld, U.; Fronze, G. G.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gajdosova, K.; Gallio, M.; Galvan, C. D.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Garg, K.; Garg, P.; Gargiulo, C.; Gasik, P.; Gauger, E. F.; Gay Ducati, M. B.; Germain, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; Gonzalez, A. S.; Gonzalez, V; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Graham, K. L.; Greiner, L. C.; Grelli, A.|info:eu-repo/dai/nl/326052577; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grion, N.; Gronefeld, J. M.; Grosa, F.; Grosse-Oetringhaus, J. F.; Grosso, R.; Gruber, L.; Grull, F. R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Guzman, I. B.; Haake, R.; Hadjidakis, C.; Hamagaki, H.; Hamar, G.; Hamon, J. C.; Harris, J. W.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Hellbär, E.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Herrmann, F.; Hess, B. A.; Hetland, K. F.; Hillemanns, H.; Hippolyte, B.; Hladky, J.; Hohlweger, B.; Horak, D.; Sorkine-Hornung, Olga; Hosokawa, R.; Hristov, P.; Hughes, C.W.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Inaba, M.; Ippolitov, M.; Irfan, M.; Isakov, V.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacak, B.; Jacazio, N.; Jacobs, P. M.; Jadhav, M. B.; Jadlovska, S.; Jadlovsky, J.; Jaelani, S.; Jahnke, C.; Jakubowska, M. J.; Janik, M. A.; Jayarathna, P. H S Y; Jena, C.; Jena, S.; Jercic, M.; Jimenez Bustamante, R. T.; Jones, P. G.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karayan, L.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L.D.|info:eu-repo/dai/nl/370530780; Keil, M.; Ketzer, B.; Khan, P.M.; Khan, Shfaqat A.; Khanzadeev, A.; Kharlov, Y.; Khatun, A.; Khuntia, A.; Kielbowicz, M. M.; Kileng, B.; Kim, D.-S.; Kim, D. W.; Kim, D. J.; Kim, H.; Kim, J. S.; Kim, J.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C; Klein, J.; Klein-Bösing, C.; Klewin, S.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.|info:eu-repo/dai/nl/371571227; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kopcik, M.; Kour, M.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.L.; Koyithatta Meethaleveedu, G.; Králik, I.; Kravčáková, A.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.|info:eu-repo/dai/nl/362845670; Kubera, A. M.; Kučera, V.; Kuhn, C.; Kuijer, P. G.|info:eu-repo/dai/nl/074064975; Kumar, A.; Kumar, J.; Kumar, L.; Kumar, S.; Kundu, Seema; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.|info:eu-repo/dai/nl/355080192; La Rocca, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lapidus, K.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lavicka, R.; Lazaridis, L.; Lea, R.; Leardini, L.; Lee, S.; Lehas, F.|info:eu-repo/dai/nl/411295721; Strunz-Lehner, Christine; Lehrbach, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Litichevskyi, V.; Ljunggren, H. M.; Llope, W. J.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Loncar, P.; Lopez, X.; López Torres, E.; Lowe, A.; Luettig, P.; Lunardon, M.; Luparello, G.|info:eu-repo/dai/nl/355080400; Lupi, M.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.|info:eu-repo/dai/nl/412461684; Marín, Alicia; Markert, C.; Marquard, M.; Martin, N. A.; Martinengo, P.; Martinez, J. A. L.; Martínez, Isabel M.; Martínez García, G.; Martinez Pedreira, M.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Mastroserio, A.; Mathis, A. M.; Matyja, A.; mayer, C.; Mazer, J.; Mazzilli, M.; Mazzoni, M. A.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Mhlanga, S.; Miake, Y.; Mieskolainen, M. M.; Mihaylov, D. L.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.|info:eu-repo/dai/nl/325781435; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.|info:eu-repo/dai/nl/369405870; Mohanty, B.; Mohisin Khan, M.; Montes, E.; Moreira De Godoy, D. A.; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Münning, K.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Myers, C. J.; Naik, B.; Nair, Rajiv; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Natal Da Luz, H.; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Negrao De Oliveira, R. A.; Nellen, L.; Nesbo, S. V.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.|info:eu-repo/dai/nl/07051349X; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Ohlson, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.|info:eu-repo/dai/nl/323375618; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Oravec, M.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Pachmayer, Y.; Pacik, V.; Pagano, D.; Pagano, P.; Paić, G.; Palni, P.; Pan, J.; Pandey, A. K.; Panebianco, S.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, J.; Park, J.-W.; Parmar, S.; Passfeld, A.; Pathak, S. P.; Paticchio, V.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.|info:eu-repo/dai/nl/304833959; Peng, X.; Pereira, L. G.; Pereira Da Costa, H.; Peresunko, D.; Perez Lezama, E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Pezzi, R. P.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L M; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Poppenborg, H.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Pozdniakov, V.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Rana, D. B.; Raniwala, R.; Raniwala, S.; Räsänen, S.; Rascanu, B. T.; Rathee, D.; Ratza, V.; Ravasenga, I.; Read, K. F.; Redlich, K.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.|info:eu-repo/dai/nl/413319628; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rodríguez Cahuantzi, M.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Rokita, P. S.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Rotondi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rueda, O. V.; Rui, R.; Russo, R.; Rustamov, A.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Saarinen, S.; Sadhu, S.; Sadovsky, S.; Šafařík, K.; Saha, S. K.; Sahlmuller, B.; Sahoo, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sandoval, A.; Sarkar, D.; Sarkar, N.; Sarma, P.; Sas, M. H.P.|info:eu-repo/dai/nl/413332993; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Scheid, H. S.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schmidt, M. O.; Schmidt, M.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Šefčík, M.; Seger, J. E.; Sekiguchi, Y.; Sekihata, D.; Selyuzhenkov, I.; Senosi, K.; Senyukov, S.; Serradilla, E.; Sett, P.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, A.; Sharma, M.; Sharma, M.; Sharma, N.; Sheikh, A. I.; Shigaki, K.; Shou, Q. Y.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R; Singhal, V.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J.M.|info:eu-repo/dai/nl/165585781; Snellman, T. W.; Song, J.; Song, M.; Soramel, F.; Sorensen, S.; Sozzi, F.; Spiriti, E.; Sputowska, I.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stankus, P.; Stenlund, E.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A P; Sugitate, T.; Suire, C.; Suleymanov, M.; Suljic, M.; Sultanov, R.; Šumbera, M.; Sumowidagdo, S.; Suzuki, K.; Swain, S.; Szabo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Tabassam, U.; Takahashi, J.; Tambave, G. J.; Tanaka, N.; Tarhini, M.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thakur, D.; Thakur, J. S.; Thomas, D.; Tieulent, R.; Tikhonov, A.; Timmins, A. R.; Toia, A.; tripathy, S.; Trogolo, S.; Trombetta, G.; Trubnikov, V.; Trzaska, W. H.; Trzeciak, B. A.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Umaka, E. N.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vala, M.; Van Der Maarel, J.|info:eu-repo/dai/nl/412860996; Van Hoorne, J. W.; van Leeuwen, M.|info:eu-repo/dai/nl/250599171; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vázquez Doce, O.; Vechernin, V.; Veen, A. M.|info:eu-repo/dai/nl/413533751; Velure, A.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Vértesi, R.; Verweij, M.|info:eu-repo/dai/nl/330542133; Vickovic, L.; Vigolo, S.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Villatoro Tello, A.; Vinogradov, A.; Vinogradov, L.; Virgili, T.; Vislavicius, V.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; Haller, B.; Vorobyev, I.; Voscek, D.; Vranic, D.; Vrláková, J.; Wagner, B.; Wagner, J.; Wang, H.|info:eu-repo/dai/nl/369509307; Wang, M.; Watanabe, D.; Watanabe, Y.; Weber, M.; Weber, S. G.; Weiser, D. F.; Wessels, J. P.; Westerhoff, U.; Whitehead, A. M.; Wiechula, J.; Wikne, J.; Wilk, G.; Wilkinson, J.; Willems, G. A.; Williams, M. C S; Windelband, B.; Witt, W. E.; Yalcin, S.; Yang, P.; Yano, S.; Yin, Z.; Yokoyama, H.; Yoo, I. K.; Yoon, J. H.; Yurchenko, V.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zardoshti, N.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhang, C.; Zhang, Z.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zimmermann, S.; Zinovjev, G.; Zmeskal, J.
2018-01-01
This letter presents the first measurement of jet mass in Pb–Pb and p–Pb collisions at √SNN = 2.76 TeV and √SNN =5.02 TeV, respectively. Both the jet energy and the jet mass are expected to be sensitive to jet quenching in the hot Quantum Chromodynamics (QCD) matter created in nuclear collisions at
Confinement in Yang-Mills: Elements of a Big Picture
International Nuclear Information System (INIS)
Shifman, M.; Unsal, Mithat
2009-01-01
This is a combined and slightly expanded version of talks delivered at 14th International QCD Conference 'QCD 08,' 7-12th July 2008, Montpellier, France, the International Conference 'Quark Confinement and the Hadron Spectrum,' Mainz, Germany, September 1-6, 2008 (Confinement 08), and the International Conference 'Approaches to Quantum Chromodynamics,' Oberwoelz, Austria, September 7-13, 2008
Research program in elementary particle theory: Progress report, January 1, 1987-December 1987
International Nuclear Information System (INIS)
Sudarshan, E.C.G.; Dicus, D.A.
1987-08-01
Progress is reported in the areas of: strings and gauge theories, mathematical physics and quantum optics, high energy physics phenomenology, quantum chromodynamic sum rules, and application of particle physics to astrophysics. Titles of DOE reports resulting from this research are listed, and the research histories of the scientific staff of the Center for Particle Theory are given
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2014-01-01
Roč. 2014, č. 6 (2014), s. 1-46 ISSN 1029-8479 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : quantum chromodynamics * ATLAS * Drell-Yan process * CERN LHC Coll * experimental results * 7000 GeV-cms Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 6.111, year: 2014
Story of the string theory. From hadrons to Planck scale
International Nuclear Information System (INIS)
Petropoulos, P.M.
2010-01-01
Originally the string theory was devised to describe the scattering between hadron particles but was quickly put aside by the success of the quantum chromodynamics. Now string theory appears in the quantum gravity theory and has been involved in almost all attempts to define a physics beyond the standard model and to unify basic interactions. (A.C.)
International Nuclear Information System (INIS)
Dainton, J.B.
1987-01-01
Four lecture courses were presented to PhD graduate students in their first year of work at British Universities. The lecture courses were entitled: Introduction to Quantum Electrodynamics, Introduction to Quantum Chromodynamics, Quantum Field Theory, Symmetries and Gauge Theories, and Topics in Modern Phenomenology. The first three lecture courses were selected for INIS and indexed separately. (U.K.)
Random walks and a simple chirally invariant lattice Hamiltonian without fermion doubling
International Nuclear Information System (INIS)
Belyea, C.I.
1992-01-01
It is shown that there is a simple chirally-invariant lattice Hamiltonian for fermions which is doubling-free but non-Hermitian and which may be valuable in lattice Hamiltonian studies of quantum chromodynamics. A connection is established between the existence of random walk representations of spinor propagators and this doubling-free formulation, in analogy with Wilson fermions. 15 refs
Czech Academy of Sciences Publication Activity Database
Adare, A.; Aidala, C.; Ajitanand, N.N.; Tomášek, Lukáš; Vrba, Václav
2017-01-01
Roč. 95, č. 7 (2017), s. 1-19, č. článku 072002. ISSN 2470-0010 Institutional support: RVO:68378271 Keywords : Drell-Yan process * fragmentation * quantum chromodynamics * factorization * violation * PYTHIA * PHENIX * 510 GeV-cms Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 4.568, year: 2016
Czech Academy of Sciences Publication Activity Database
Aaboud, M.; Aad, G.; Abbott, B.; Chudoba, Jiří; Hejbal, Jiří; Hladík, Ondřej; Jakoubek, Tomáš; Kepka, Oldřich; Kroll, Jiří; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Penc, Ondřej; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek
2017-01-01
Roč. 95, č. 11 (2017), s. 1-27, č. článku 112005. ISSN 2470-0010 Institutional support: RVO:68378271 Keywords : ATLAS * CERN LHC Coll * differential cross section * quantum chromodynamics * perturbation theory * perturbation theory * higher-order Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 4.568, year: 2016
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Růžička, Pavel; Schovancová, Jaroslava; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Tic, Tomáš; Vrba, Václav
2013-01-01
Roč. 2013, č. 7 (2013), s. 1-35 ISSN 1029-8479 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : ATLAS * CERN * scattering * higher-order * jet * multiple production * parton * showers * associated production * leptonic decay * quantum chromodynamics Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 6.220, year: 2013
High energy physics at Tufts University. Progress report, July 16, 1985-July 15, 1986
International Nuclear Information System (INIS)
1986-01-01
Experimental projects in high energy physics that are reported include the Soudan-II Nucleon Decay Project, neutrino physics, pion and kaon production of charm and charm-strange states, and multiparticle spectrometer studies at Fermilab. Theoretical efforts include general kinematic description of polarization in scattering processes and spin phenomenology, as well as applications of quantum chromodynamic perturbation theory
Measurement of beauty production at HERA using events with muons and jets
Czech Academy of Sciences Publication Activity Database
Aktas, A.; Andreev, V.; Anthonis, T.; Cvach, Jaroslav; Herynek, Ivan; Reimer, Petr; Sedlák, Kamil; Zálešák, Jaroslav
2005-01-01
Roč. 41, - (2005), s. 453-467 ISSN 1434-6044 R&D Projects: GA MŠk(CZ) LA 116; GA MŠk(CZ) LN00A006 Institutional research plan: CEZ:AV0Z10100502 Keywords : HI experiment * ep scattering * quantum chromodynamics * cross section Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.209, year: 2005
Dynamical breakdown of chiral symmetry in vectorial theories: QED and QCD
International Nuclear Information System (INIS)
Garcia, J.C.M.
1987-01-01
Using a variational approach for the Effective Potential for composite operators we dicuss the dynamical breakdown of chiral symmetry in two vectorial theories: Quantum Electrodynamics (QED) and Quantum Chromodynamics (QCD). We study the energetic aspects of the problem calculating the Effective Potential with the asymptotic nonperturbative solutions of the Schwinger-Dyson equation for the fermion selfenergy. (author) [pt
International Nuclear Information System (INIS)
Anon.
1979-01-01
Is quantum chromodynamics (QCD) the ultimate theory of hadronic phenomena? Or, put more sceptically, can one tell QCD from a hole in the ground? This is the title of a new theory roadshow, which after a successful premiere at CERN went on to attract a large audience at Erice, Sicily, during the recent international school of subnuclear physics
2013 European School of High-Energy Physics
Perez, G; ESHEP 2013
2015-01-01
The European School of High-Energy Physics is intended to give young physicists an introduction to the the- oretical aspects of recent advances in elementary particle physics. These proceedings contain lecture notes on the Standard Model of electroweak interactions, quantum chromodynamics, Higgs physics, physics beyond the Standard Model, flavour physics, and practical statistics for particle physicists.
Energy Technology Data Exchange (ETDEWEB)
Anon.
1979-10-15
Is quantum chromodynamics (QCD) the ultimate theory of hadronic phenomena? Or, put more sceptically, can one tell QCD from a hole in the ground? This is the title of a new theory roadshow, which after a successful premiere at CERN went on to attract a large audience at Erice, Sicily, during the recent international school of subnuclear physics.
WWNPQFT-2010 - Slides of the presentations
International Nuclear Information System (INIS)
Fried, H.M.; Huber, M.Q.; Grandou, T.; Bianchi, E.; Gracey, J.; Reys, V.; Jevicki, A.; Ferrante, D.; Bouakaz, K.; Spielmann, D.; Cucchieri, A.; Culetu, H.; Gelis, F.; Zwanziger, D.; Candelpergher, B.; Bender, C.
2013-01-01
This document is made up of the slides of the presentations. The object of this workshop is to consolidate and publicize new efforts in non-perturbative field theories. The main topics are quantum chromodynamics, Yang-Mills theory, effective locality, the Gribov-Zwanziger Lagrangian, and renormalization. A presentation is dedicated to the initial stages of high energy nucleus-nucleus collisions
Czech Academy of Sciences Publication Activity Database
Abazov, V. M.; Abbott, B.; Acharya, B.S.; Kupčo, Alexander; Lokajíček, Miloš
2013-01-01
Roč. 88, č. 7 (2013), "072008-1"-"072008-22" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG12006 Institutional support: RVO:68378271 Keywords : D0 * Fermilab * hadroproduction * parton * distribution function * photon * associated production * jet * rapidity * higher-order 1 * quantum chromodynamics Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.864, year: 2013
Energy Technology Data Exchange (ETDEWEB)
Anon.
1987-10-15
The 'Standard Model' of modern particle physics, with the quantum chromodynamics (QCD) theory of inter-quark forces superimposed on the unified electroweak picture, is still unchallenged, but it is not the end of physics. This was the message at the big International Symposium on Lepton and Photon Interactions at High Energies, held in Hamburg from 27-31 July.
On QCD sum rules of the Laplace transform type and light quark masses
International Nuclear Information System (INIS)
Narison, S.
1981-04-01
We discuss the relation between the usual dispersion relation sum rules and the Laplace transform type sum rules in quantum chromodynamics. Two specific examples corresponding to the S-coupling constant sum rule and the light quark masses sum rules are considered. An interpretation, within QCD, of Leutwyler's formula for the current algebra quark masses is also given
Where are we in particle physics
International Nuclear Information System (INIS)
Treiman, S.B.
1981-01-01
The author gives a brief description of the current status of high energy physics regarding quantum chromodynamics and the unified theory of weak and electromagnetic interactions. In this connection the mass generation of leptons and quarks by spontaneous symmetry breaking is considered. Finally an outlook is given to grand unification with special regards to the proton decay. (HSI).
Obe approximation of NN scattering in bag-model QCD
International Nuclear Information System (INIS)
Bakker, B.L.G.; Maslow, J.N.; Weber, H.J.
1981-01-01
A partial-wave helicity-state analysis of nucleon-nucleon scattering is carried out in momentum space. Its basis is a one-boson and two-pion exchange amplitude from bag-model quantum chromodynamics. The resulting phase shifts and bound-state parameters of the deuteron are compared with data up to laboratory energies of approx. equal to 350 MeV. (orig.)
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Růžička, Pavel; Schovancová, Jaroslava; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Tic, Tomáš; Vrba, Václav
2013-01-01
Roč. 725, 4-5 (2013), 223-242 ISSN 0370-2693 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : ATLAS * scattering * quantum chromodynamics * perturbation the ory * higher-order 2 * differential cross section * measured * electron * pair production Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 6.019, year: 2013
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2014-01-01
Roč. 2014, č. 5 (2014), s. 1-67 ISSN 1029-8479 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : differential cross section * measured * quantum chromodynamics * perturbation the ory * higher-order 1 * experimental results * ATLAS * CERN LHC Coll Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 6.111, year: 2014
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Gunther, Jaroslav; Jakoubek, Tomáš; Juránek, Vojtěch; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Růžička, Pavel; Schovancová, Jaroslava; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Tic, Tomáš; Vrba, Václav
2013-01-01
Roč. 720, 1-3 (2013), s. 32-51 ISSN 0370-2693 R&D Projects: GA MŠk LA08032 Institutional support: RVO:68378271 Keywords : ATLAS * CERN * vector boson * transverse momentum * quantum chromodynamics * perturbation the ory * resummation * Monte Carlo * angular correlation * dilepton Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 6.019, year: 2013
Phase transitions: the lattice QCD approach
International Nuclear Information System (INIS)
Gavai, R.V.
1986-01-01
Recent results in the field of finite temperature lattice quantum chromodynamics (QCD) are presented with special emphasis on comparison of the different methods used to incorporate the dynamical fermions. Attempts to obtain a nonperturbative estimate of the velocity of sound in both the hadronic and quark-gluon phase are summarized along with the results. 15 refs., 7 figs
Nonperturbative confinement in quantum chromodynamics : II. Mandelstam’s gluon propagator
Atkinson, D.; Johnson, P. W.; Stam, K.
It is shown that Mandelstam’s approximate equation for the gluon propagator has a solution with very singular infrared behavior. At the origin in the squared momentum variable there are a double pole, a branch‐point, and an accumulation of complex first‐sheet branch‐points. Although the double pole
Self-consistence equations for extended Feynman rules in quantum chromodynamics
International Nuclear Information System (INIS)
Wielenberg, A.
2005-01-01
In this thesis improved solutions for Green's functions are obtained. First the for this thesis essential techniques and concepts of QCD as euclidean field theory are presented. After a discussion of the foundations of the extended approach for the Feynman rules of QCD with a systematic approach for the 4-gluon vertex a modified renormalization scheme for the extended approach is developed. Thereafter the resummation of the Dyson-Schwinger equations (DSE) by the appropriately modified Bethe-Salpeter equation is discussed. Then the leading divergences for the 1-loop graphs of the resummed DSE are determined. Thereafter the equation-of-motion condensate is defined as result of an operator-product expansion. Then the self-consistency equations for the extended approaches are defined and numerically solved. (HSI)
Two aspects of the quantum chromodynamics' transition at finite temperature
International Nuclear Information System (INIS)
Zhang, Bo
2011-01-01
This thesis concerns two aspects of the relation between chiral symmetry breaking and confinement. The first aspect is the relations between different topological objects. The relation between monopoles and center vortices and the relation between instantons and monopoles are well established, in this thesis, we explore the relation between instantons (of finite temperature, called calorons) and center vortices in SU(2) and SU(3) gauge theory in Chapter 3 and Chapter 4, respectively. The second aspect is about the order parameters. The dual condensate introduced by E. Bilgici et al. is a novel observable that relates the order parameter of chiral symmetry breaking (chiral condensate) and confinement (Polyakov loop). In this thesis, we investigate the dual condensate on dynamical staggered fermions and explore a new dual operator: the dual quark density in Chapter 5.
Renormalization scheme-dependence of perturbative quantum chromodynamics corrections to quarkonia
International Nuclear Information System (INIS)
Dentamaro, A.V.
1985-05-01
QCD radiative corrections to physical quantities are studied using Stevenson's principle of minimal sensitivity (PMS) to define the renormalization. We examine several naive potentials (Cornell group, power law and logarithmic), as well as the more sophisticated Richardson model in order to determine the spectra for the non-relativistic heavy charmonium and bottomonium systems. Predictions are made for the values of hyperfine splittings, leptonic and hadronic decay widths and E1 transition rates for these families of mesons. It is shown that good agreement with experimental data may be achieved by using a constant value of Λ/sub QCD/, which is determined by the PMS scheme and the potential model
Problems at the interface between perturbative and nonperturbative quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.; Bodwin, G.T.; Lepage, G.P.
1983-06-01
Predictions based on perturbative QCD rest on three premises: (1) that hadronic interactions become weak in strength at small invariant separation; (2) that the perturbative expansion in α/sub s/(Q) is well-defined; and (3) factorization: all effects of collinear singularities, confinement, nonperturbative interactions, and bound state dynamics can be isolated at large momentum transfer in terms of structure functions, fragmentation functions, or in the case of exclusive processes, distribution amplitudes. The assumption that the perturbative expansion for hard scattering amplitudes converges has certainly not been demonstrated; in addition, there are serious ambiguities concerning the choice of renormalization scheme and scale choice Q 2 for the expansion in α/sub s/(Q 2 ). We will discuss a new procedure to at least partly rectify the latter problem. In the case of exclusive processes, the factorization of hadronic amplitudes at large momentum transfer in the form of distribution amplitudes convoluted with hard scattering quark-gluon subprocess amplitudes can be demonstrated systematically to all orders in α/sub s/(Q 2 ). In the case of inclusive reactions, factorization remains an ansatz; general all-orders proofs do not exist because of the complications of soft initial state interactions for hadron-induced processes; thus far factorization has only been verified to two loops beyond lowest order in a regime where the applicability of perturbation theory is in doubt. However, we shall show that a necessary condition for the validity of factorization in inclusive reactions is that the momentum transfer must be large compared to the (rest frame) length of the target. We review the present status of the factorization ansatz. 52 references
Meson bound states and inclusive hardon scattering in quantum chromodynamics
International Nuclear Information System (INIS)
Beavis, D.R.
1980-01-01
In the first part we study the charmonium and UPSILON systems with a simple Coulomb plus linear potential. The parameters of the potential are determined by the charmonium states other than 1 S 0 states. We successfully predict that the states X(2830) and x(3450) are not the 1 S 0 partners of J/psi and psi'. The same effective potential also gives a good description of the UPSILON system. The Lorentz nature of the confinement potential is determined to be an equal mixture of vector and scalar. In the second part we extend a method for obtaining bound states and wavefunctions for relativistic confined systems. The important aspect of this treatment is the input of the asymptotic expansion of the two-point functions. We test the bound state approximation for a system defined by an equivalent potential V(r) = lambda 2 tanh 2 (g 2 r/lambda). Excellent results are obtained, even though a threshold is present. Finally, in the third section, we analyze the 100 GeV/c π - p→π 0 X data of Barnes et al. for moderate t, 1.5 less than or equal to -t less than or equal to 4.0 (GeV/c) 2 with the constituent scattering models. We obtain very good agreement in normalization and the x and t behavior of dsigma/dtdx using the FF1 model. The analysis of π - p→etaX gives additional support to this interpretation. The predictions of perturbative QCD and FF1 for π - p→π 0 X are given
Experimental results on QCD [Quantum Chromodynamics] from e+e- annihilation
International Nuclear Information System (INIS)
de Boer, W.
1987-09-01
A review is given on QCD results from studying e + e - annihilation with the PEP and PETRA storage rings with special emphasis on jet physics and the determination of the strong coupling constant α/sub s/. 92 refs., 28 figs., 3 tabs
A model of unified quantum chromodynamics and Yang-Mills gravity
International Nuclear Information System (INIS)
HSU Jongping
2012-01-01
Based on a generalized Yang-Mills framework, gravitational and strong interactions can be unified in analogy with the unification in the electroweak theory. By gauging T(4) × [SU(3)] color in flat space-time, we have a unified model of chromo-gravity with a new tensor gauge field, which couples universally to all gluons, quarks and anti-quarks. The space-time translational gauge symmetry assures that all wave equations of quarks and gluons reduce to a Hamilton-Jacobi equation with the same 'effective Riemann metric tensors’ in the geometric-optics (or classical) limit. The emergence of effective metric tensors in the classical limit is essential for the unified model to agree with experiments. The unified model suggests that all gravitational, strong and electroweak interactions appear to be dictated by gauge symmetries in the generalized Yang-Mills framework. (author)
A model of unified quantum chromodynamics and Yang-Mills gravity
Institute of Scientific and Technical Information of China (English)
HSU Jong-Ping
2012-01-01
Based on a generalized Yang-Mills framework,gravitational and strong interactions can be unified in analogy with the unification in the clectroweak theory.By gauging T(4) × [SU(3)]color in fiat space-time,we have a unified model of chromo-gravity with a new tensor gauge field,which couples universally to all gluons,quarks and anti-quarks.The space-time translational gauge symmetry assures that all wave equations of quarks and gluons reduce to a Hamilton-Jacobi equation with the same ‘effective Riemann metric tensors' in the geometric-optics (or classical) limit.The emergence of effective metric tensors in the classical limit is essential for the unified model to agree with experiments.The unified model suggests that all gravitational,strong and electroweak interactions appear to be dictated by gauge symmetries in the generalized Yang-Mills framework.
Infrared structure and large Psub(T) behavior of quantum chromodynamics
International Nuclear Information System (INIS)
Rafael, Eduardo de.
1977-09-01
The study of the infrared structure of QCD in perturbation theory is an interesting problem per se regardless of its relationship to the confinement problem. The ultimate motivation for the study of the large transverse momentum behavior of QCD is to provide a field theoretic framework to the large Psub(T)-phenomena in hadronic interactions. As a first step towards that aim it is of interest to explore the possibility that the QCD Green's functions in 'some' regions of exceptional momenta, like the large-Psub(T) regime, may still obey some kind of renormalization group type equations
Chromodynamics of hadronic and nuclear reactions in the perturbative vacuum
International Nuclear Information System (INIS)
Cohen-Tannoudji, G.; Navelet, H.
1983-09-01
In this report we discuss two topics which can be considered as positive practical tests of QCD: an estimate of the rise of total hadronic cross sections by means of QCD at the leading logarithm approximation and an estimate of the dependence in the atomic number of structure functions of nuclei (the so called EMC effect also by means of QCD)
Renormalizable Abelian-projected effective gauge theory derived from quantum chromodynamics
International Nuclear Information System (INIS)
Kondo, Kei-ichi; Shinohara, Toru
2001-01-01
We show that an effective Abelian gauge theory can be obtained as a renormalizable theory from QCD in the maximal Abelian gauge. The derivation improves in a systematic manner the previous version that was obtained by one of the authors and was referred to as the Abelian-projected effective gauge theory. This result supports the view that we can construct an effective Abelian gauge theory from QCD without losing characteristic features of the original non-Abelian gauge theory. In fact, it is shown that the effective coupling constant in the resulting renormalizable theory has a renormalization-scale dependence governed by the β-function that is exactly the same as that of the original Yang-Mills theory, irrespective of the choice of gauge fixing parameters of the maximal Abelian gauge and the parameters used for identifying the dual variables. Moreover, we evaluate the anomalous dimensions of the fields and parameters in the resultant theory. By choosing the renormalized parameters appropriately, we can switch the theory into an electric or a magnetic theory. (author)
Quantum chromodynamics as effective theory of quarks and composite gluons
International Nuclear Information System (INIS)
Fuss, T.
2004-01-01
The dynamics of quarks is described by a nonperturbatively regularized NJL model which is canonically quantized and fulfil a probability interpretation. The quantum field theory of this model is formulated in a functional space. The wave functions of the quarks and gluons are calculated as eigenstates of Hard-Core equations and the gluons are considered as relativistic bound states of colored quark-antiquark pairs. The effective dynamics of the quarks and gluons is derived from weak mapping in functional space. This leads to the functional formulation of the phenomenological SU(3) local gauge invariant quark-gluon equations in temporal gauge. This means that the local gauge symmetry is a dynamical effect resulting from the quark model
Quantum chromodynamics and deep inelastic e - N scattering at TRISTAN
International Nuclear Information System (INIS)
Muta, Taizo
1979-04-01
An introductory survey is given on the formulation of QCD in deep inelastic lepton-hadron scatterings. Typical predictions of QCD are presented in the kinematical region of TRISTAN, including detailed descriptions of the scaling violation, QCD correction to the current algebra sum rules, problem of quark masses and higher order effects. Some suggestions for experiments at TRISTAN are made. (author)
Rapporteur talks at Singapore (deep inelastic scattering) and at Hadron 90 (conference summary)
International Nuclear Information System (INIS)
Close, F.E.
1990-11-01
This talk begins by reviewing the early years of deep inelastic scattering with particular reference to some theoretical work. Current highlights include an agreed uniform set of structure functions, polarised structure functions, possible violations of the Gottfried sum rule, deep inelastic scattering off nuclei and anticipated breakdown of naive perturbative quantum chromodynamics QCD as x → 0 at HERA. (author)
Chiral condensates and QCD vacuum in two dimensions
International Nuclear Information System (INIS)
Christiansen, H.R.
1997-04-01
We analyze the chiral symmetries of flavored quantum chromodynamics in two dimensions and show the existence of the chiral condensates within the path-integral approach. The massless and massive cases are discussed as well,for arbitrary finite and infinite number of colors. Our results put forward the question of topological issues when matter is in the fundamental representation of the gauge group. (author)
Energy Technology Data Exchange (ETDEWEB)
Ecker, Gerhard [Wien Univ. (Austria). Fakultaet fuer Physik
2017-07-01
The following topics are dealt with: Physics around 1900, the way to quantum mechanics, quantum field theory with quantum electrodynamics as prototype, the crisis of quantum field theory, from the beta decay to the electroweak gauge theory, quantum chromodynamics as quantum field theory of the strong nuclear force, the standard model of the fundamental interactions, physics beyond the standard model. (HSI)
Further studies of Fermi-motion effects in lepton scattering from nuclear targets
International Nuclear Information System (INIS)
Bodek, A.; Ritchie, J.L.
1981-01-01
We have calculated the ratio of deep-inelastic structure functions of nuclear targets to the sum of free-neutron and -proton structure functions. The calculations incorporate structure-function fits which are based on quantum-chromodynamic considerations. This paper is an addendum to an earlier publication in which we calculated the Fermi-motion corrections using other fits to the nucleon structure functions
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Gallus, Petr; Gunther, Jaroslav; Havránek, Miroslav; Hruška, I.; Juránek, Vojtěch; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Kvasnička, Jiří; Lipinský, L.; Lokajíček, Miloš; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Panušková, M.; Růžička, Pavel; Schovancová, Jaroslava; Šícho, Petr; Staroba, Pavel; Taševský, Marek; Tic, Tomáš; Valenta, J.; Vrba, Václav
2011-01-01
Roč. 83, č. 5 (2011), "052005-1"-"052005-33" ISSN 1550-7998 R&D Projects: GA MŠk LA08015; GA MŠk LA08032 Institutional research plan: CEZ:AV0Z10100502 Keywords : photon: direct production * higher-order: 1 * quantum chromodynamics: perturbation theory * ATLAS * LHC Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.558, year: 2011
Czech Academy of Sciences Publication Activity Database
Abdallah, J.; Abreu, A.; Adam, W.; Mašík, Jiří; Němeček, Stanislav; Řídký, Jan; Todorovová, Šárka; Trávníček, Petr; Vrba, Václav
2011-01-01
Roč. 71, č. 2 (2011), 1-50 ISSN 1434-6044 R&D Projects: GA MŠk LA08015 Institutional research plan: CEZ:AV0Z10100502 Keywords : parton: shower s * bottom: fragmentation function * jet: hadronization * CERN * LEP * DELPHI * quantum chromodynamics * PYTHIA * ALEPH * OPAL * SLD Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.631, year: 2011
Theoretical aspects of electroweak and other interactions in medium energy nuclear physics
International Nuclear Information System (INIS)
Mukhopadhyay, N.C.
1989-01-01
In the project year 1989--1990, progress has been made towards the theoretical modeling of the photoproduction of eta mesons off nucleons and in complex nuclei. Exploration of hadron models has produced interesting perspectives on the violation of gauge invariance due to truncation of the quark model space. New projects in perturbative quantum chromodynamics and spectrum generating algebras for hadrons have been started
Concept for an Electron Ion Collider (EIC) detector built around the BaBar solenoid
PHENIX Collaboration; Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Alfred, M.; Apadula, N.; Aramaki, Y.; Asano, H.; Atomssa, E. T.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.
2014-01-01
The PHENIX collaboration presents here a concept for a detector at a future Electron Ion Collider (EIC). The EIC detector proposed here, referred to as ePHENIX, will have excellent performance for a broad range of exciting EIC physics measurements, providing powerful investigations not currently available that will dramatically advance our understanding of how quantum chromodynamics binds the proton and forms nuclear matter.
Gauge theory and elementary particles
International Nuclear Information System (INIS)
Zwirn, H.
1982-01-01
The present orientation of particle physics, founded on local gauge invariance theories and spontaneous symmetry breaking is described in a simple formalism. The application of these ideas to the latest theories describing electromagnetic and weak interactions (Glashow, Weinberg, Salam models) and strong interactions, quantum chromodynamics, is presented so as to give a general picture of the mechanisms subtending these theories [fr
Forward jet production in deep inelastic scattering at HERA
Czech Academy of Sciences Publication Activity Database
Aktas, A.; Andreev, V.; Anthonis, A.; Cvach, Jaroslav; Reimer, Petr; Sedlák, Jaroslav; Zálešák, Jaroslav
2006-01-01
Roč. 46, - (2006), s. 27-42 ISSN 1434-6044 R&D Projects: GA MŠk(CZ) LC527; GA MŠk(CZ) 1P05LA259 Institutional research plan: CEZ:AV0Z10100502 Keywords : HI experiment * ep scattering * deep inelastic * cross section * quantum chromodynamics Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.251, year: 2006
A determination of electroweak parameters at HERA
Czech Academy of Sciences Publication Activity Database
Aktas, A.; Andreev, V.; Anthonis, A.; Cvach, Jaroslav; Reimer, Petr; Sedlák, Jaroslav; Zálešák, Jaroslav
2006-01-01
Roč. 632, - (2006), s. 35-42 ISSN 0370-2693 R&D Projects: GA MŠk(CZ) LA 116; GA MŠk(CZ) LN00A006 Grant - others:GAUK(CZ) 175/2000 Institutional research plan: CEZ:AV0Z10100502 Keywords : HI experiment * ep scattering * quantum chromodynamics Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.043, year: 2006
International Nuclear Information System (INIS)
Anon.
1987-01-01
The 'Standard Model' of modern particle physics, with the quantum chromodynamics (QCD) theory of inter-quark forces superimposed on the unified electroweak picture, is still unchallenged, but it is not the end of physics. This was the message at the big International Symposium on Lepton and Photon Interactions at High Energies, held in Hamburg from 27-31 July
Color-dielectric model as an explanation of the Nolen-Schiffer anomaly
International Nuclear Information System (INIS)
Williams, A.G.; Thomas, A.W.
1986-01-01
We discuss the quantum chromodynamically motivated color-dielectric model originally proposed by Nielsen and Patkos and show, using some straightforward approximations, that it can lead to charge-symmetry breaking effects in nuclei. We then show, using a local density approximation and standard nuclear structure properties, that for suitable choices of parameters this color-dielectric model can explain the Nolen-Schiffer anomaly
Inclusive jet cross section at D0
International Nuclear Information System (INIS)
Bhattacharjee, M.
1996-09-01
Preliminary measurement of the central (|η| ≤ 0.5) inclusive jet cross sections for jet cone sizes of 1.0, 0.7, and 0.5 at D null based on the 1992-1993 (13.7 pb -1 ) and 1994-1995 (90 pb -1 ) data samples are presented. Comparisons to Next-to-Leading Order (NLO) Quantum Chromodynamics (QCD) calculations are made
QCD and Fermi gas model interpretations of the E.M.C. effect
International Nuclear Information System (INIS)
Close, F.E.
1986-07-01
It is suggested that there is a correspondence between the quantum chromo-dynamic (QCD) approach and the conventional model of nucleon binding which leads to nuclear properties being related to the anomalous dimensions of QCD. This in turn may lead to a 'unified' approach to nuclear and quark-gluon physics. A discussion is given with respect to the EMC effect. (UK)
Twisted mass lattice QCD with non-degenerate quark masses
International Nuclear Information System (INIS)
Muenster, Gernot; Sudmann, Tobias
2006-01-01
Quantum Chromodynamics on a lattice with Wilson fermions and a chirally twisted mass term is considered in the framework of chiral perturbation theory. For two and three numbers of quark flavours, respectively, with non-degenerate quark masses the pseudoscalar meson masses and decay constants are calculated in next-to-leading order including lattice effects quadratic in the lattice spacing a
Energy Technology Data Exchange (ETDEWEB)
Diefenthaler, Markus
2010-08-15
Intention of the present thesis was the study of transverse-momentum dependent quark distribution functions. In the focus stood the Fourier analysis of azimutal single-spin asymmetries of pions and charged kaons performed within the HERMES experiment. These asymmetries were reconstructed from deep-inelastic scattering events on a transversely polarized proton target and decomposed in Fourier components. In the framework of quantum chromodynamics such components can be interpreted as folding of quark distribution and fragmentation functions. By the analysis of the transverse-momentum dependent quark distribution functions the study of spin-orbit correlations in the internal of the nucleon was made possible. By this conclusions on the orbital angular momentum of the quarks can be drawn. The extracted Fourier components extend the hitherto available informations on the transverse-momentum dependent quark distribution functions remarkably. The presented Fourier analysis made not only a detection of the Collins and Sivers effects possible, but beyond the extraction of the signals of the pretzelosity and worm-gear distributions. The so obtained results will conclusively contribute to the understanding of future measurements in this field and furthermore make possible a test of fundamental predictions of quantum chromodynamics.
tmLQCD: a program suite to simulate Wilson twisted mass lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Urbach, Carsten [Institut fuer Physik, Humboldt-Universitaet, Berlin (Germany)
2009-05-15
We discuss a program suite for simulating Quantum Chromodynamics on a 4-dimensional space-time lattice. The basic Hybrid Monte Carlo algorithm is introduced and a number of algorithmic improvements are explained. We then discuss the implementations of these concepts as well as our parallelisation strategy in the actual simulation code. Finally, we provide a user guide to compile and run the program. (orig.)
Antiquark distributions in pion and nucleon
International Nuclear Information System (INIS)
Arakelian, G.G.; Boreskov, K.G.; Kaidalov, A.B.
1980-01-01
Relation between the antiquark distributions in pion and nucleon, based on the π-exchange hypothesis, is derived. The antiquark distributions in proton are calculated with the data on the valence antiquark distribution in pion as input. Results of the calculation agree with the experimental data. The role of the peripheral mechanism in formulation of the initial conditions for the chromodynamical evolution equations is discussed
Using anti pp annihilation to find exotic mesons
International Nuclear Information System (INIS)
Sharpe, S.R.
1987-10-01
Present data suggests that a number of mesons have been found which cannot be accommodated in standard anti qq multiplets. Theory suggests that such exotic mesons should exist in the spectrum of Quantum Chromodynamics, but provides little guide to their properties. It is argued that a high luminosity, low energy anti pp machine would be a powerful tool with which to search for such exotics
Some remarks on chiral symmetry in dense matter
International Nuclear Information System (INIS)
Kaellman, C.G.; Montonen, C.
1982-01-01
The restoration of chiral symmetry in quantum chromodynamics as the temperature T and the chemical potential vertical stroke μ vertical stroke are increased is discussed qualitatively and using effective field theories. The latter are shown not to give reliable quantitative estimates. It is argued that a dilute gas of instantons cannot be the main dynamical agent responsible for the breakdown of chiral symmetry. (orig.)
tmLQCD: a program suite to simulate Wilson twisted mass lattice QCD
International Nuclear Information System (INIS)
Jansen, Karl; Urbach, Carsten
2009-05-01
We discuss a program suite for simulating Quantum Chromodynamics on a 4-dimensional space-time lattice. The basic Hybrid Monte Carlo algorithm is introduced and a number of algorithmic improvements are explained. We then discuss the implementations of these concepts as well as our parallelisation strategy in the actual simulation code. Finally, we provide a user guide to compile and run the program. (orig.)
Phenomenology of cosmic phase transitions
International Nuclear Information System (INIS)
Kaempfer, B.; Lukacs, B.; Paal, G.
1989-11-01
The evolution of the cosmic matter from Planck temperature to the atomic combination temperature is considered from a phenomenological point of view. Particular emphasis is devoted to the sequence of cosmic phase transitions. The inflationary era at the temperature of the order of the grand unification energy scale and the quantum chromodynamic confinement transition are dealt with in detail. (author) 131 refs.; 26 figs
International Nuclear Information System (INIS)
Harari, H.
1978-10-01
A general overview is given in this high energy physics conference summary. Quantum chromodynamics as a theory of strong interactions and studied by experimental tests, SU(2) x U(1) theory of weak and electromagnetic interactions and its experimental tests, weak interactions above 100 GeV, simple unification of weak and electromagnetic interactions, and the grand and the ultimate unifications with extended supergravity are discussed. 28 references
Strangeness production at low Q.sup.2./sup. in deep-inelastic ep scattering at HERA
Czech Academy of Sciences Publication Activity Database
Aaron, F.D.; Alexa, C.; Andreev, V.; Cvach, Jaroslav; Reimer, Petr; Zálešák, Jaroslav
2009-01-01
Roč. 61, č. 2 (2009), s. 185-205 ISSN 1434-6044 R&D Projects: GA MŠk LC527 Grant - others:GA MŠk(CZ) 1P05LA259 Institutional research plan: CEZ:AV0Z10100502 Keywords : H1 experimen * ep scattering, * cross section * quantum chromodynamics Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 2.746, year: 2009
Quark-antiquark potentials from QCD and quarkonium spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Laschka, Alexander
2012-12-11
This work examines the interaction between a heavy quark and its antiquark. By combining perturbative and non-perturbative methods, interaction potentials with an extended range of validity are derived from quantum chromodynamics. Using these potentials the spectra of the quarkonium bound states are calculated and compared with experimental results. This provides a new approach for determining the masses of the charm and bottom quark.
Identified charged hadron production in p+p collisions at sqrt{s}=200 and 62.4 GeV
Czech Academy of Sciences Publication Activity Database
Adare, A.; Afanasiev, S.; Aidala, C.; Kubart, J.; Mašek, L.; Mikeš, P.; Růžička, Pavel; Tomášek, Lukáš; Vrba, Václav
2011-01-01
Roč. 83, č. 6 (2011), "064903-1"-"064903-29" ISSN 0556-2813 Institutional research plan: CEZ:AV0Z10100502 Keywords : transverse momentum: momentum spectrum * hadron: yield * higher-order: 1 * RHIC * PHENIX * quantum chromodynamics: perturbation theory Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.308, year: 2011 http://link.aps.org/doi/10.1103/PhysRevC.83.064903
Feynman integrals and difference equations
International Nuclear Information System (INIS)
Moch, S.; Schneider, C.
2007-09-01
We report on the calculation of multi-loop Feynman integrals for single-scale problems by means of difference equations in Mellin space. The solution to these difference equations in terms of harmonic sums can be constructed algorithmically over difference fields, the so-called ΠΣ * -fields. We test the implementation of the Mathematica package Sigma on examples from recent higher order perturbative calculations in Quantum Chromodynamics. (orig.)
Analytic stochastic regularization and gauge theories
International Nuclear Information System (INIS)
Abdalla, E.; Gomes, M.; Lima-Santos, A.
1987-04-01
We prove that analytic stochatic regularization braks gauge invariance. This is done by an explicit one loop calculation of the two three and four point vertex functions of the gluon field in scalar chromodynamics, which turns out not to be geuge invariant. We analyse the counter term structure, Langevin equations and the construction of composite operators in the general framework of stochastic quantization. (author) [pt
1997 European School of high-energy physics. Proceedings
International Nuclear Information System (INIS)
Ellis, N.; Neubert, M.
1998-01-01
The European School of High-Energy Physics is intended to give young experimental physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lectures on Field Theory, the Standard Model, Quantum Chromodynamics, Flavour Physics, Physics at LEP II and Heavy Ion physics, as well as reports on Cosmology, Dark Matter and a Quantum Theory of two-dimensional space-time. (orig.)
International Nuclear Information System (INIS)
Nachtmann, O.
1992-01-01
The modern theory of strong interactions - Quantum Chromodynamics (QCD), where quarks and gluons carrying the 'colour' quantum number play the essential role, is twenty years old. This birthday was duly celebrated at RWTH Aachen from 9-13 June, where recurring themes were - what has been achieved in the past twenty years?, where do we stand?, and what are the perspectives for the future?
Latest Minimum Bias and Underlying Event measurements with the ATLAS Detector
Cairo, Valentina Maria; The ATLAS collaboration
2018-01-01
The modeling of Minimum Bias and Underlying Event is a crucial component in the description of soft Quantum Chromodynamics processes. They are both described by multi-parton interaction models, the result of proton collisions containing more than one partonic interaction due to collective and beam remnant effects. Recent ATLAS studies aimed at measuring Charged-Particle distributions and the properties of the Underlying Event are presented.
Super-hypernuclei in the quark-shell model, 2
International Nuclear Information System (INIS)
Terazawa, Hidezumi.
1989-07-01
By following the previous paper, where the quark-shell model of nuclei in quantum chromodynamics is briefly reviewed, a short review of the MIT bag model of nuclei is presented for comparison and a simple estimate of the Hλ ('hexalambda') mass is also made for illustration. Furthermore, an even shorter review of the 'nucleon cluster model' of nuclei is presented for further comparison. (J.P.N.)
1997 European School of high-energy physics. Proceedings
Energy Technology Data Exchange (ETDEWEB)
Ellis, N; Neubert, M [eds.
1998-05-20
The European School of High-Energy Physics is intended to give young experimental physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lectures on Field Theory, the Standard Model, Quantum Chromodynamics, Flavour Physics, Physics at LEP II and Heavy Ion physics, as well as reports on Cosmology, Dark Matter and a Quantum Theory of two-dimensional space-time. (orig.)
Measurements of the Deuteron Elastic Structure Function A(Q2) for 0.7
International Nuclear Information System (INIS)
L. C. Alexa; B. D. Anderson; K. A. Aniol; K. Arundell; L. Auerbach; F. T. Baker; J. Berthot; P. Y. Bertin; W. Bertozzi; L. Bimbot; W. U. Boeglin; E. J. Brash; V. Breton; H. Breuer; E. Burtin; J. R. Calarco; L. S. Cardman; C. Cavata; C.-C. Chang; J.-P. Chen; E. Chudakov; E. Cisbani; D. S. Dale; N. Degrande; R. De Leo; A. Deur; N. d'Hose; B. Diederich; J. J. Domingo; M. B. Epstein; L. A. Ewell; J. M. Finn; K. G. Fissum; H. Fonvieille; B. Frois; S. Frullani; H. Gao; J. Gao; F. Garibaldi; A. Gasparian,; S. Gilad; R. Gilman; A. Glamazdin; C. Glashausser; J. Gomez; V. Gorbenko; J.-O. Hansen; R. Holmes; M. Holtrop; C. Howell; G. M. Huber; C. Hyde-Wright; M. Iodice; C. W. de Jager; S. Jaminion; J. Jardillier; M. K. Jones; C. Jutier,; W. Kahl; S. Kato; A. T. Katramatou; J. J. Kelly; S. Kerhoas; A. Ketikyan; M. Khayat; K. Kino; L. H. Kramer; K. S. Kumar; G. Kumbartzki; M. Kuss; G. Lavessiere; A. Leone; J. J. LeRose; M. Liang; R. A. Lindgren; N. Liyanage; G. J. Lolos; R. W. Lourie; R. Madey,; K. Maeda; S. Malov; D. M. Manley; D. J. Margaziotis; P. Markowitz; J. Marroncle; J. Martino; C. J. Martoff; K. McCormick; J. McIntyre; R. L. J. van der Meer; S. Mehrabyan; Z.-E. Meziani; R. Michaels; G. W. Miller; J. Y. Mougey; S. K. Nanda; D. Neyret; E. A. J. M. Offermann; Z. Papandreou; C. F. Perdrisat; R. Perrino; G. G. Petratos; S. Platchkov; R. Pomatsalyuk; D. L. Prout; V. A. Punjabi; T. Pussieux; G. Quemener; R. D. Ransome; O. Ravel; Y. Roblin; D. Rowntree; G. Rutledge; P. M. Rutt; A. Saha; T. Saito; A. J. Sarty; A. Serdarevic,; T. Smith; K. Soldi; P. Sorokin; P. A. Souder; R. Suleiman; J. A. Templon; T. Terasawa; L. Todor; H. Tsubota; H. Ueno; P. E. Ulmer; G. M. Urciuoli; L. Van Hoorebeke; P. Vernin; B. Vlahovic; H. Voskanyan; J. W. Watson; L. B. Weinstein; K. Wijesooriya; R. Wilson; B. B. Wojtsekhowski; D. G. Zainea; W-M. Zhang; J. Zhao; Z.-L. Zhou
1999-01-01
The deuteron elastic structure function A(Q 2 ) has been extracted in the range 0.7 2 2 from cross section measurements of elastic electron-deuteron scattering in coincidence using the Hall A Facility of Jefferson Laboratory. The data are compared to theoretical models, based on the impulse approximation with the inclusion of meson-exchange currents, and to predictions of quark dimensional scaling and perturbative quantum chromodynamics
Computing Properties of Hadrons, Nuclei and Nuclear Matter from Quantum Chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Savage, Martin J. [Univ. of Washington, Seattle, WA (United States)
2017-03-24
This project was part of a coordinated software development effort which the nuclear physics lattice QCD community pursues in order to ensure that lattice calculations can make optimal use of present, and forthcoming leadership-class and dedicated hardware, including those of the national laboratories, and prepares for the exploitation of future computational resources in the exascale era. The UW team improved and extended software libraries used in lattice QCD calculations related to multi-nucleon systems, enhanced production running codes related to load balancing multi-nucleon production on large-scale computing platforms, and developed SQLite (addressable database) interfaces to efficiently archive and analyze multi-nucleon data and developed a Mathematica interface for the SQLite databases.
Spontaneous chiral symmetry breaking and effective quark masses in quantum chromodynamics
International Nuclear Information System (INIS)
Miransky, V.A.
1982-01-01
The ultraviolet asymptotics of the dynamical effective quark mass is determined directly from the equation for the fermion mass function. The indications about the character of the dynamics of the spontaneous chiral symmetry breaking in QCD are obtained
Microcanonical and hybrid simulations of lattice quantum chromodynamics with dynamical fermions
International Nuclear Information System (INIS)
Sinclair, D.K.
1986-10-01
Lattice QCD is simulated using Microcanonical and Hybrid (Micro-canonical/Langevin) methods to facilitate the inclusion of dynamical fermions (quarks). We report on simulations with 4 flavors of light dynamical quarks on a 10 3 x 6 lattice to study the finite temperature deconfinement/chiral transition which should be observable in relativistic heavy ion collisions, as a function of quark mass. A first order transition is observed at large mass, weakens at intermediate mass and strengthens for very small quark mass
Challenges to quantum chromodynamics: Anomalous spin, heavy quark, and nuclear phenomena
International Nuclear Information System (INIS)
Brodsky, S.J.
1989-11-01
The general structure of QCD meshes remarkably well with the facts of the hadronic world, especially quark-based spectroscopy, current algebra, the approximate point-like structure of large momentum transfer inclusive reactions, and the logarithmic violation of scale invariance in deep inelastic lepton-hadron reactions. QCD has been successful in predicting the features of electron-positron and photon-photon annihilation into hadrons, including the magnitude and scaling of the cross sections, the shape of the photon structure function, the production of hadronic jets with patterns conforming to elementary quark and gluon subprocesses. The experimental measurements appear to be consistent with basic postulates of QCD, that the charge and weak currents within hadrons are carried by fractionally-charged quarks, and that the strength of the interactions between the quarks, and gluons becomes weak at short distances, consistent with asymptotic freedom. Nevertheless in some cases, the predictions of QCD appear to be in dramatic conflict with experiment. The anomalies suggest that the proton itself as a much more complex object than suggested by simple non-relativistic quark models. Recent analyses of the proton distribution amplitude using QCD sum rules points to highly-nontrival proton structure. Solutions to QCD in one-space and one-time dimension suggest that the momentum distributions of non-valence quarks in the hadrons have a non-trival oscillatory structure. The data seems also to be suggesting that the ''intrinsic'' bound state structure of the proton has a non- negligible strange and charm quark content, in addition to the ''extrinsic'' sources of heavy quarks created in the collision itself. 144 refs., 46 figs., 2 tabs
A model of confinement for quantum chromodynamics in 2+1 dimensions
International Nuclear Information System (INIS)
Silva Filho, A.C. da.
1986-01-01
A dieletric mechanism of QCD in 2 + 1 dimensions is studied. This model yields confinement of two opposite color charges which are infinitely massive, via a linear potential. A functional expression for the dielectric parameter ε and studied analitical and numerical the resulting constitutive equations is obtained. A perturbative approach of these yields the non-leading contributions to the asymptotic potential as well for the boundary of the confinement domain. The results obtained for the transversal width of the confinement domain, considering large separations R of color charges, indicate that increases like R 2/3 , behavior which differs from the one suggested by the string models. (author) [pt
Color transparency and the structure of the proton in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.
1989-06-01
Many anomalies suggest that the proton itself is a much more complex object than suggested by simple non-relativistic quark models. Recent analyses of the proton distribution amplitude using QCD sum rules points to highly-nontrivial proton structure. Solutions to QCD in one-space and one-time dimension suggest that the momentum distributions of non-valence quarks in the hadrons have a non-trivial oscillatory structure. The data seems also to be suggesting that the ''intrinsic'' bound state structure of the proton has a non-negligible strange and charm quark content, in addition to the ''extrinsic'' sources of heavy quarks created in the collision itself. As we shall see in this lecture, the apparent discrepancies with experiment are not so much a failure of QCD, but rather symptoms of the complexity and richness of the theory. An important tool for analyzing this complexity is the light-cone Fock state representation of hadron wavefunctions, which provides a consistent but convenient framework for encoding the features of relativistic many-body systems in quantum field theory. 121 refs., 44 figs., 1 tab
Hadronic wave functions and high momentum transfer interactions in quantum chromodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.; Huang, T.; Lepage, G.P.
1983-01-01
This chapter emphasizes the utility of a Fock state representation of the meson and baryon wave functions as a means not only to parametrize the effects of bound state dynamics in QCD phenomena, but also to interrelate exclusive, inclusive, and higher twist processes. Discusses hadronic wave functions in QCD, measures of hadronic wave functions (form factors of composite systems, form factors of mesons, the meson distribution amplitude); large momentum transfer exclusive processes (two-photon processes); deep inelastic lepton scattering; and the phenomenology of hadronic wave functions (measures of hadron wave functions, constraints on the pion and proton valence wave function, quark jet diffraction excitation, the ''unveiling'' of the hadronic wave function and intrinsic charm). Finds that the testing ground of perturbative QCD where rigorous, definitive tests of the theory can be made can now be extended throughout a large domain of large momentum transfer exclusive and inclusive lepton, photon, and hadron reactions
International Nuclear Information System (INIS)
Kharzeev, D.
2004-01-01
In this talk I discuss recent advances in Quantum Chromo-Dynamics, in particular the progress in understanding the collective dynamics of the theory. I emphasise the significance of the RHIC program for establishing the properties of hot and dense QCD matter and for understanding the dynamics of the theory at the high parton density, strong color field frontier. Hopes and expectations for the future are discussed as well
Self-consistent areas law in QCD
International Nuclear Information System (INIS)
Makeenko, Yu.M.; Migdal, A.A.
1980-01-01
The problem of obtaining the self-consistent areas law in quantum chromodynamics (QCD) is considered from the point of view of the quark confinement. The exact equation for the loop average in multicolor QCD is reduced to a bootstrap form. Its iterations yield new manifestly gauge invariant perturbation theory in the loop space, reproducing asymptotic freedom. For large loops, the areas law apprears to be a self-consistent solution
Czech Academy of Sciences Publication Activity Database
Abazov, V. M.; Abbott, B.; Acharya, B.S.; Kupčo, Alexander; Lokajíček, Miloš
2013-01-01
Roč. 719, 4-5 (2013), s. 354-361 ISSN 0370-2693 R&D Projects: GA MŠk(CZ) LG12006 Institutional support: RVO:68378271 Keywords : D0 * harm * associated production * bottom * associated production * parton * distribution function * quantum chromodynamics * perturbation theory * anti-p p Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 6.019, year: 2013 http://www.sciencedirect.com/science/article/pii/S0370269313000580
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Gallus, Petr; Gunther, Jaroslav; Hruška, I.; Juránek, Vojtěch; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lipinský, L.; Lokajíček, Miloš; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Panušková, M.; Růžička, Pavel; Schovancová, Jaroslava; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Tic, Tomáš; Valenta, J.; Vrba, Václav; Zeman, Martin
2012-01-01
Roč. 706, 4-5 (2012), s. 295-313 ISSN 0370-2693 R&D Projects: GA MŠk LA08032 Institutional research plan: CEZ:AV0Z10100502 Keywords : jet: bottom * channel cross section * quantum chromodynamics * perturbation theory * ATLAS * lepton transverse momentum * dilepton mass spectrum Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.569, year: 2012 http://www.sciencedirect.com/science/article/pii/S0370269311014389
Measurement of the ratio of three-jet to two-jet cross sections in ppˉ collisions at √s=1.96 TeV
Czech Academy of Sciences Publication Activity Database
Abazov, V. M.; Abbott, B.; Acharya, B.S.; Kupčo, Alexander; Lokajíček, Miloš
2013-01-01
Roč. 720, 1-3 (2013), s. 6-12 ISSN 0370-2693 R&D Projects: GA MŠk(CZ) LG12006 Institutional support: RVO:68378271 Keywords : D0 * Fermilab * jet * multiple production * cross section * ratio * measured * quantum chromodynamics * perturbation theory * jet * transverse momentum * anti-p p Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 6.019, year: 2013 http://www.sciencedirect.com/science/article/pii/S0370269313000890
Feynman graphs and gauge theories for experimental physicists. 2. rev. ed.
International Nuclear Information System (INIS)
Schmueser, P.
1995-01-01
This book is an introduction to the foundations of quantum field theory with special regards to gauge theory. After a general introduction to relativistic wave equations the concept of Feynman graphs is introduced. Then after an introduction to the phenomenology of weak interactions and the principle of gauge invariance the standard model of the electroweak interaction is presented. Finally quantum chromodynamics is described. Every chapter contains exercise problems. (HSI)
Heavy quark fragmentation into polarized quarkonium in the heavy quark effective theory
International Nuclear Information System (INIS)
Martynenko, A.P.; Saleev, V.A.
1996-01-01
Fragmentation of b-antiquark into polarized B* c -mesons is investigated within the framework of effective theory of heavy quarks. Functions of b fragmentation into longitudinally polarized and transversely polarized S-wave states of b c are calculated with an exact regard tot he first order corrections by 1/m b . Agreement of the results obtained with the corresponding calculations, performed in the quantum chromodynamics, is shown. 17 refs.; 2 figs
Mulders, Martijn
2017-01-01
The Asia–Europe–Pacific School of High-Energy Physics is intended to give young physicists an introductionto the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lecturenotes on quantum field theory and the electroweak Standard Model, the theory of quantum chromodynamics,flavour physics and CP violation, neutrino physics, heavy-ion physics, cosmology and a brief introduction tothe principles of instrumentation and detectors for particle physics.
Evidence for longitudinal photon polarization in muon-pair production by pions
International Nuclear Information System (INIS)
Anderson, K.J.; Coleman, R.N.; Karhi, K.P.; Newman, C.B.; Pilcher, J.E.; Rosenberg, E.I.; Thaler, J.J.; Hogan, G.E.; McDonald, K.T.; Sanders, G.H.; Smith, A.J.S.
1979-01-01
Data on μ-pair production by pions are examined as a function of x and P/sub T/ for longitudinal photon polarization. Evidence in the form of a sin 2 theta* term in the helicity angular distribution is observed for x near 1. This is conclusive evidence that production in this region is not predominantly through on-shell quark annihilation. The result is consistent with a calculation based on quantum chromodynamics
Effects of the fragmentation models on the determination of αsub(S) in e+e- annihilation
International Nuclear Information System (INIS)
Lavagne, Y.
1982-06-01
Jet phenomenology is presented and quantum chromodynamic notions necessary to this study comprehension are given. Device is described, together with data acquisition and different steps of hadronic event selection. Three jet topology events are selected from presented variables and methods. Two models with different fragmentation processes are used to determine αsub(S). Results for each model are gathered and display the fragmentation process influence on αsub(S) value [fr
LHC Detectors and Early Physics
Dissertori, Guenther
2010-01-01
In this review I sketch the basic criteria and boundary conditions which have guided the design of the LHC detectors. The discussion will concentrate on the so-called general-purpose experiments, ATLAS and CMS. After an overview of the detector's characteristics and performance, I will elaborate on the expected measurements of hard processes, with emphasis on jet and vector boson production, i.e., tests of Quantum Chromodynamics (QCD) and Electroweak Physics.
A confining and asymptotically free solution for the renormalization group invariant charge
International Nuclear Information System (INIS)
Kellett, B.H.
1978-01-01
The central role of the invariant charge in applications of the renormalization group to quantum chromodynamics is discussed. The general structure of the invariant charge is examined, and it is shown to be a non-singular function of q 2 for all finite non-zero q 2 . At q 2 = 0 and q 2 = +or- infinity shows that QCD is asymptotically free. Some applications of these general results are discussed
International Nuclear Information System (INIS)
Ammosov, V.V.; Usubov, Z.U.; Zhigunov, V.P.
1990-01-01
A problem of parametric analysis of the scaling violation in deep inelastic lepton-nucleon interactions in the framework of quantum chromodynamics (QCD) is considered. For a correct consideration of the experimental resolution we use the χ 2 -method, which is demonstrated by numeric experiments and analysis of the 15-foot bubble chamber neutrino experimental data. The model parameters obtained in this approach differ noticeably from those obtained earlier. (orig.)
The transition matrix element Agq(N) of the variable flavor number scheme at O(α3s)
International Nuclear Information System (INIS)
Ablinger, J.; Hasselhuhn, A.; Schneider, C.; Manteuffel, A. von
2014-01-01
We calculate the massive operator matrix element A (3) gq (N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This is the first complete transition function needed in the variable flavor number scheme obtained at O(α 3 s ). A fist independent recalculation is performed for the contributions ∝ N F of the 3-loop anomalous dimension γ (2) gq (N).
International Nuclear Information System (INIS)
DeGrand, T.
1997-01-01
These lectures provide an introduction to lattice methods for nonperturbative studies of Quantum Chromodynamics. Lecture 1: Basic techniques for QCD and results for hadron spectroscopy using the simplest discretizations; lecture 2: Improved actions--what they are and how well they work; lecture 3: SLAC physics from the lattice-structure functions, the mass of the glueball, heavy quarks and α s (M z ), and B-anti B mixing. 67 refs., 36 figs
International Nuclear Information System (INIS)
Heusch, C.A.
1985-01-01
The postulated existence of hadrons with no quark content, implied by the non-Abelian nature of quantum chromodynamics, has been the object of much experimental activity. Recent data from radiative psi decay permit a confrontation of available evidence with the most simple-minded criteria for their appearance. In the absence of compellingly positive evidence we give a rating of the relative merits of several possible candidates. 36 references, 17 figures
International Nuclear Information System (INIS)
Matveev, V.A.; Tavkhelidze, A.N.
2006-01-01
A brief review is given of the priority works which were mainly carried out at the Laboratory of Theoretical Physics, JINR, and devoted to the introduction to hadron physics of the concept of color and colored quarks, and to the description of hadrons in the framework of the model of quasi-free quarks. These ideas play a key role in the modern theory of strong interactions - quantum chromodynamics
1988-03-01
In quantum flavordynamics the nonzero expectation values of the vacuum Higgs field produces the spontaneous symmetry breaking that gives rise to the...mas- sive intermediate vector bosons that mediate the weak interactions.’ In quan- tum chromodynamics the vacuum polarization leads to the concepts of...be associated with massive gauge bosons that are connected with the excited states of the internal phases of bulk matter, i.e., internal spin waves of
International Nuclear Information System (INIS)
Roberts, L.E.
1988-01-01
For colliding beams of several species of ions we compare thermal to perturbative quantum chromodynamic contributions for inclusive large mass muon pair production by using a hydrodynamic model to estimate the temperatures of the quark-gluon plasma produced by each species. The production of high energy dimuons with M ≅-4 GeV, will be favored energetically by the quark-gluon plasma. 10 refs., 4 figs., 2 tabs
Unambiguity of renormalization group calculations in QCD
International Nuclear Information System (INIS)
Vladimirov, A.A.
1979-01-01
A detailed analysis of the reduction of ambiguities determined by an arbitrary renormalization scheme is presented for the renormalization group calculations of physical quantities in quantum chromodynamics (QCD). Some basic formulas concerning the renormalization-scheme dependence of Green's and renormalization group functions are given. A massless asymptotically free theory with one coupling constant g is considered. In conclusion, several rules for renormalization group calculations in QCD are formulated
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Gallus, Petr; Gunther, Jaroslav; Hruška, I.; Juránek, Vojtěch; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lipinský, L.; Lokajíček, Miloš; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Panušková, M.; Růžička, Pavel; Schovancová, Jaroslava; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Tic, Tomáš; Valenta, J.; Vrba, Václav; Zeman, Martin
2012-01-01
Roč. 707, č. 5 (2012), 418-437 ISSN 0370-2693 R&D Projects: GA MŠk LA08032 Institutional research plan: CEZ:AV0Z10100502 Keywords : jet: bottom * ATLAS * quantum chromodynamics * perturbation the ory * jet: transverse momentum * CERN LHC Coll * jet: rapidity * p p interaction Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.569, year: 2012 http://www.sciencedirect.com/science/article/pii/S0370269311015036
5th CERN - Latin-American School of High-Energy Physics
Grojean, C; Spiropulu, M
2010-01-01
The CERN-Latin-American School of High-Energy Physics is intended to give young physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lectures on quantum field theory, quantum chromodynamics, physics beyond the Standard Model, neutrino physics, flavour physics and CP violation, particle cosmology, high-energy astro-particle physics, and heavy-ion physics, as well as trigger and data acquisition, and commissioning and...