WorldWideScience

Sample records for chromodynamics

  1. Classical chromodynamics

    International Nuclear Information System (INIS)

    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)

  2. Quantum chromodynamics

    International Nuclear Information System (INIS)

    These proceedings mark the fourth workshop on Quantum Chromodynamics held at the American University of Paris during the week of 1-6 june 1998. 8 half-day sessions, each dealing with a distinct theme within the general QCD framework. The different topics treated are: 1) diffractive production and the pomeron, 2) high energy scattering and the pomeron, 3) thermal and other fluctuations, 4) hadrons physics, 5) strings, branes and duality, 6) conventional and unconventional QCD, 7) media effects in scattering, 7) media effects, statistics and spin correlations in QCD, 8) lattice methods, 9) lattice methods and QCD theory, and 10) new and gauge-invariant methods in QCD/Quantum field theory

  3. Complementarity in Wormhole Chromodynamics

    OpenAIRE

    Lo, Hoi-Kwong; Lee, Kai-Ming; Preskill, John

    1993-01-01

    The electric charge of a wormhole mouth and the magnetic flux ``linked'' by the wormhole are non-commuting observables, and so cannot be simultaneously diagonalized. We use this observation to resolve some puzzles in wormhole electrodynamics and chromodynamics. Specifically, we analyze the color electric field that results when a colored object traverses a wormhole, and we discuss the measurement of the wormhole charge and flux using Aharonov-Bohm interference effects. We suggest that wormhol...

  4. Perturbative quantum chromodynamics

    CERN Document Server

    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

  5. Topological Aspects of Quantum Chromodynamics

    NARCIS (Netherlands)

    Hooft, G. 't

    2000-01-01

    Absolute confinement of its color charges is a natural property of gauge theories such as quantum chromodynamics. On the one hand, it can be attributed to the existence of color-magnetic monopoles, a topological feature of the theory, but one can also maintain that all non-Abelian gauge theories con

  6. Quantum chromodynamics and hadron jets

    International Nuclear Information System (INIS)

    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.)

  7. Parallel computing and quantum chromodynamics

    CERN Document Server

    Bowler, K C

    1999-01-01

    The study of Quantum Chromodynamics (QCD) remains one of the most challenging topics in elementary particle physics. The lattice formulation of QCD, in which space-time is treated as a four- dimensional hypercubic grid of points, provides the means for a numerical solution from first principles but makes extreme demands upon computational performance. High Performance Computing (HPC) offers us the tantalising prospect of a verification of QCD through the precise reproduction of the known masses of the strongly interacting particles. It is also leading to the development of a phenomenological tool capable of disentangling strong interaction effects from weak interaction effects in the decays of one kind of quark into another, crucial for determining parameters of the standard model of particle physics. The 1980s saw the first attempts to apply parallel architecture computers to lattice QCD. The SIMD and MIMD machines used in these pioneering efforts were the ICL DAP and the Cosmic Cube, respectively. These wer...

  8. Multiparticle production and quantum chromodynamics

    CERN Document Server

    Dremin, I M

    2002-01-01

    The theory of strong interactions, quantum chromodynamics (QCD), is quite successful in the prediction and description of main features of multiparticle production processes at high energies. The general perturbative QCD approach to these processes (mainly to e+e- -annihilation) is briefly formulated and its problems are discussed. It is shown that the analytical calculations at the parton level with the low-momentum cut-off reproduce experimental data on the hadronic final state in multiparticle production processes at high energies surprisingly accurately even though the perturbative expansion parameter is not very small. Moreover, it is important that the perturbative QCD has been able not only to describe the existing data but also to predict many bright qualitatively new phenomena.

  9. Quantum chromodynamics at large distances

    International Nuclear Information System (INIS)

    The properties of quantum chromodynamics (QCD)at large distances are considered in the framework of traditional quantum field theory. The parameters that determine the infrared region are determined self-consistently by means of the renormalization-group method. Recent studies that confirm a singular infrared asymptotic behavior M2 /(k2 )2 of the gluon propagator are reviewed. Solutions of the Schwinger--Dyson equation for the quark propagator are found with the necessary properties: spontaneous breaking of the chiral invariance and a nonperturbative nature. The infrared behaviors of the lowest Green's functions are used to calculate the vacuum expectation values of the gluon and quark fields. Good agreement between the calculated vacuum expectation values and their phenomenological values is obtained. The study of the behavior of QCD at large distances leads to the conclusion that at the present level of development of the theory two possibilities can be discussed. The first is the well-known confinement hypothesis; the second has been called incomplete confinement and necessarily implies that open color can be observed. It is shown that the second possibility does not contradict existing experiments. Experimental data on anomalous nuclear fragments and ultra-high-energy radiation from the galactic source Cygnus X-3 are considered as evidence for incomplete confinement. The importance of searches for states with open color is emphasized

  10. Studies of Quantum Chromodynamics at the LHC

    CERN Document Server

    Carli, Tancredi; Schumann, Steffen

    2015-01-01

    A successful description of hadron-hadron collision data demands a profound understanding of quantum chromodynamics. Inevitably, the complexity of strong-interaction phenomena requires the use of a large variety of theoretical techniques -- from perturbative cross-section calculations up to the modelling of exclusive hadronic final states. Together with the unprecedented precision of the data provided by the experiments in the first running period of the LHC, a solid foundation of hadron-hadron collision physics at the TeV scale could be established that allowed the discovery of the Higgs boson and that is vital for estimating the background in searches for new phenomena. This chapter on studies of quantum chromodynamics at the LHC is part of a recent book on the results of LHC Run 1 and presents the advances in theoretical methods side-by-side with related key measurements in an integrated approach.

  11. Color-charge algebras in Adler's chromodynamics

    International Nuclear Information System (INIS)

    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

  12. Quark sector of Coulomb gauge Quantum Chromodynamics

    CERN Document Server

    Popovici, Carina

    2011-01-01

    The quark sector of Coulomb gauge quantum chromodynamics is considered within the functional integral approach. The quark contributions to the Dyson-Schwinger equations are derived and one-loop perturbative results for the two-point functions are presented. The problem of confinement is addressed in the heavy quark limit, by rewriting the generating functional of quantum chromodynamics in terms of a heavy quark mass expansion. By restricting to leading order in this expansion and considering only the two-point functions of the Yang-Mills sector, the rainbow-ladder approximation to the gap and Bethe-Salpeter equations is shown to be exact. Analytic nonperturbative solutions to the Bethe-Salpeter equation for quark-antiquark bound states and Faddeev equation for three-quark bound states, in the case of equal quark separations, are presented. The quark-antiquark and three-quark confining potentials are derived and a direct connection between the temporal gluon propagator and the corresponding string tensions is ...

  13. Quark-Quark Forces in Quantum Chromodynamics

    CERN Document Server

    Arkhipov, A A

    2014-01-01

    By single-time reduction technique of Bethe-Salpeter formalism for two-fermion systems analytical expressions for the quasipotential of quark-quark interactions in QCD have been obtained in one-gluon exchange approximation. The influence of infrared singularities of gluon Green`s functions on the character of quark-quark forces in QCD has been investigated. The way the asymptotic freedom manifests itself in terms of two-quark interaction quasipotential in quantum chromodynamics is shown. Consistent relativistic consideration of quark interaction problem by single-time reduction technique in QFT allows one to establish a nontrivial energy dependence of the two-quark interaction quasipotential. As a result of the energy dependence of the interaction quasipotential, the character of the forces changes qualitatively during the transition from the discrete spectrum (the region of the negative values of the binding energy) to the continuous spectrum (that of the positive values of the binding energy): the smooth be...

  14. Massive quark polarization in Quantum Chromodynamics subprocesses

    International Nuclear Information System (INIS)

    It is well known that the single polarization asymmetries are large in hyperon production in contrast with naive Quantum Chromodynamics predictions. We have explored the possibility of polarization of quarks in QCD subprocesses, assuming that the quark mass can be significant at energies of interest. The fourth order contribution to the single spin asymmetry in each important subprocess for strange quark production is calculated. Mass dependence and the kinematical properties of the polarization of the strange quark in the partons' center-of-mass frame are discussed. The s-quark polarization in the hadrons' center-of-mass frame is obtained by performing the convolution integrations with the initial state parton distribution functions. A fit to the hyperon polarization is presented that reproduces the unique and striking kinematic dependence of the data. This is evidence that the ''seed'' of the polarization is in the basic scattering process and it is dominated by the gluon fusion subprocess. 31 figs

  15. Random Matrix Theory and Quantum Chromodynamics

    CERN Document Server

    Akemann, Gernot

    2016-01-01

    These notes are based on the lectures delivered at the Les Houches Summer School in July 2015. They are addressed at a mixed audience of physicists and mathematicians with some basic working knowledge of random matrix theory. The first part is devoted to the solution of the chiral Gaussian Unitary Ensemble in the presence of characteristic polynomials, using orthogonal polynomial techniques. This includes all eigenvalue density correlation functions, smallest eigenvalue distributions and their microscopic limit at the origin. These quantities are relevant for the description of the Dirac operator spectrum in Quantum Chromodynamics with three colours in four Euclidean space-time dimensions. In the second part these two theories are related based on symmetries, and the random matrix approximation is explained. In the last part recent developments are covered including the effect of finite chemical potential and finite space-time lattice spacing, and their corresponding orthogonal polynomials. We also give some ...

  16. Calculation of baryon masses in quantum chromodynamics

    International Nuclear Information System (INIS)

    The polarization operator of quark currents with the baryon quantum numbers is considered in quantum chromodynamics. The non-zero mean vacuum of the field operator products are taken into account. The sum rules are obtained assuming that in the virtuality region approximately 1 GeV, among the mean vacuum values violating the chiral invariance, the most important is . Saturating these sum rules by the lowest baryonic states one is able to calculate the masses of the isobar Δ and nucleon N, Msub(Δ) 1.4 GeV, Msub(N) = 1 GeV, up to 15 % through the known value . The mass splitting in the baryonic decuplet Msub(Σ*) - Msub(Δ) = 125 MeV is calculated in the first order in the current strange quark mass msub(s) = 150 MeV. Certain results for that baryonic resonances have been obtained

  17. Nuclear Physics from Lattice Quantum Chromodynamics

    CERN Document Server

    Savage, Martin J

    2015-01-01

    Quantum Chromodynamics and Quantum Electrodynamics, both renormalizable quantum field theories with a small number of precisely constrained input parameters, dominate the dynamics of the quarks and gluons - the underlying building blocks of protons, neutrons, and nuclei. While the analytic techniques of quantum field theory have played a key role in understanding the dynamics of matter in high energy processes, they encounter difficulties when applied to low-energy nuclear structure and reactions, and dense systems. Expected increases in computational resources into the exascale during the next decade will provide the ability to determine a range of important strong interaction processes directly from QCD using the numerical technique of Lattice QCD. This will complement the nuclear physics experimental program, and in partnership with new thrusts in nuclear many-body theory, will enable unprecedented understanding and refinement of nuclear forces and, more generally, the visible matter in our universe. In th...

  18. Novel nuclear phenomena in quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Hadronic and nuclear phenomena in quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1987-06-01

    Many of the key issues in understanding quantum chromodynamics involves processes at intermediate energies. We discuss 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 - as tools for probing hadron structure and the propagation of quark and gluon jets in nuclei. Many of these processes can be studied in electroproduction, utilizing internal targets in storage rings. We also review several areas where there has been significant theoretical progress in determining the form of hadron and nuclear wavefunctions, including QCD sum rules, lattice gauge theory, and discretized light-cone quantization. 98 refs., 40 figs., 2 tabs.

  20. Effective action approach to quantum chromodynamics

    International Nuclear Information System (INIS)

    Though the Lagrangian of quantum chromodynamics is well known, it has proven extremely difficult to derive precisely all its consequences to compare with experiment. Approximations based on physical reasoning must be made. One method is to calculate the effective action for some particularly simple configuration of gluons and use this to analyze an arbitrary system of interacting quarks. In the first chapter, the one-loop correction to the gluon propagator is computed in two different ways - dimensional regularization and Schwinger's proper time method. The renormalization mass parameters appearing in the two treatments can then be related and the exact one-loop effective action of a constant gluon field can be expressed in terms of the experimentally determinable Λ/sub MS/. In the following chapter, the interaction of a heavy quark-antiquark pair governed by this action is considered and it is shown how the spectrum, and, in particular, the spin splittings of the bound states can be found. Due to asymptotic freedom, a massive quarkonium is analogous to a non-relativistic electromagnetic system. At short distances, the results are the same as those derived from perturbation theory though, for example, the hyperfine structure arises in a different way. At large distances, the analysis is qualitative but our results agree with the predictions of strong coupling lattice gauge theories

  1. 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.

  2. Quantum chromodynamics effects in electroweak and Higgs physics

    Indian Academy of Sciences (India)

    Frank Petriello

    2012-10-01

    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 effects and experimental cuts, and to the use of scale variations as estimates of theoretical uncertainties.

  3. Quantum Chromodynamics and Nuclear Physics at Extreme Energy Density

    International Nuclear Information System (INIS)

    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.

  4. U matrix construction for Quantum Chromodynamics through Dirac brackets

    International Nuclear Information System (INIS)

    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.)

  5. Simple model of the ground state of quantum chromodynamics

    International Nuclear Information System (INIS)

    A proposal for the form of the ground-state wave function of quantum chromodynamics is made. It is shown to lead to the phenomenology of the MIT Bag Model. The parameters of this model are related to the fundamental scale parameter of QCD. 2 tables

  6. Automated Code Generation for Lattice Quantum Chromodynamics and beyond

    CERN Document Server

    Barthou, Denis; Dolbeau, Romain; Grosdidier, Gilbert; Eisenbeis, Christina; Kruse, Michael; Pene, Olivier; Petrov, Konstantin; Tadonki, Claude

    2014-01-01

    We present here our ongoing work on a Domain Specific Language which aims to simplify Monte-Carlo simulations and measurements in the domain of Lattice Quantum Chromodynamics. The tool-chain, called Qiral, is used to produce high-performance OpenMP C code from LaTeX sources. We discuss conceptual issues and details of implementation and optimization. The comparison of the performance of the generated code to the well-established simulation software is also made.

  7. Clothed Particles in Quantum Electrodynamics and Quantum Chromodynamics

    Science.gov (United States)

    Shebeko, Alexander

    2016-03-01

    The notion of clothing in quantum field theory (QFT), put forward by Greenberg and Schweber and developed by M. Shirokov, is applied in quantum electrodynamics (QED) and quantum chromodynamics (QCD). Along the guideline we have derived a novel analytic expression for the QED Hamiltonian in the clothed particle representation (CPR). In addition, we are trying to realize this notion in QCD (to be definite for the gauge group SU(3)) when drawing parallels between QCD and QED.

  8. 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.

  9. Progress toward the effective Quantum Chromodynamic Lagrangian from symmetry considerations

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Foundations of quantum chromodynamics: Perturbative methods in gauge theories

    International Nuclear Information System (INIS)

    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

  11. Quantum chromodynamics: A theory of the nuclear force

    International Nuclear Information System (INIS)

    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

  12. Local gauge symmetry and confinement in quantum chromodynamics

    International Nuclear Information System (INIS)

    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

  13. Hadronic correlations in quantum chromodynamics on the lattice

    International Nuclear Information System (INIS)

    The quantum chromodynamics (QCD), the quantum field theory of strong interactions cannot be solved in the case of small momentum transfer by the usual perturbative methods. To this non-perturbative regime belong especially bound matter states, hadrons. A procedure for the calculation of their properties directly from the fundamental fields of QCD is the numerical evaluation of euclidean path integrals in discretized space-time. For this QCD is formulated as lattice gauge theory. In the present study the author presents an extensive didactical look into this methodics and explains the concrete realization by means of the calculation of hadronic correlations

  14. Chiral Relaxation Time at the Chiral Crossover of Quantum Chromodynamics

    CERN Document Server

    Ruggieri, M; Chernodub, M

    2016-01-01

    We study microscopic processes responsible for chirality flips in the thermal bath of Quantum Chromodynamics at finite temperature and zero baryon chemical potential. We focus on the temperature range where the crossover from chirally broken phase to quark-gluon plasma takes place, namely $T \\simeq (150, 200)$ MeV. The processes we consider are quark-quark scatterings mediated by collective excitations with the quantum number of pions and $\\sigma$-meson, hence we refer to these processes simply as \\sugg{to} one-pion (one-$\\sigma$) exchange\\sugg{s}. We use a Nambu-Jona-Lasinio model to compute equilibrium properties of the thermal bath, as well as the relevant scattering kernel to be used in the collision integral to estimate the chiral relaxation time $\\tau$. We find $\\tau\\simeq 0.1 \\div 1$ fm/c around the chiral crossover.

  15. Resolution issues of nucleon spin in quantum chromodynamics

    International Nuclear Information System (INIS)

    Lively discussions have been exchanged around the question whether it was possible to completely resolve nucleon spin to the contribution of the intrinsic spin of quarks/gluons and orbital angular momentum, without a contradiction to the color gauge invariance of quantum chromodynamics. This paper firstly showed what performs an essential role in the resolution issues of gauge invariance of nucleon spin, especially in its uniqueness issues, is the invariance toward Lorentz boost in the direction of the momentum of nucleon. What plays a crucial role in the resolution issues of nucleon spin is Lorentz symmetry, and gauge symmetry plays only a minor role. This paper next compared the advantages of two nucleon spin resolutions that are physically non-equivalent, namely, the resolution of canonical. (A.O.)

  16. Quantum chromodynamics at high energy and statistical physics

    CERN Document Server

    Munier, S

    2009-01-01

    When hadrons are scattered at high energies, strong color fields, whose dynamics is described by quantum chromodynamics (QCD), are generated at the interaction point. If one represents these fields in terms of partons (quarks and gluons), the average number densities of the latter saturate at ultrahigh energies. At that point, nonlinear effects become predominant in the dynamical equations. The hadronic states that one gets in this regime of QCD are generically called ``color glass condensates''. Our understanding of scattering in QCD has benefited from recent progress in statistical and mathematical physics. The evolution of hadronic scattering amplitudes at fixed impact parameter in the regime where nonlinear parton saturation effects become sizable was shown to be similar to the time evolution of a system of classical particles undergoing reaction-diffusion processes. The dynamics of such a system is essentially governed by equations in the universality class of the stochastic Fisher-Kolmogorov-Petrovsky-P...

  17. Quantum chromodynamics at high energy and noisy traveling waves

    CERN Document Server

    Munier, S

    2012-01-01

    When hadrons scatter at high energies, strong color fields, whose dynamics is described by quantum chromodynamics (QCD), are generated at the interaction point. If one represents these fields in terms of partons (quarks and gluons), the average number densities of the latter saturate at ultrahigh energies. At that point, nonlinear effects become predominant in the dynamical equations. The hadronic states that one gets in this regime of QCD are generically called "color glass condensates". Our understanding of scattering in QCD has benefited from recent progress in statistical and mathematical physics. The evolution of hadronic scattering amplitudes at fixed impact parameter in the regime where nonlinear parton saturation effects become sizable was shown to be similar to the time evolution of a system of classical particles undergoing reaction-diffusion processes. The dynamics of such a system is essentially governed by equations in the universality class of the stochastic Fisher-Kolmogorov-Petrovsky-Piscounov...

  18. The CT14 Global Analysis of Quantum Chromodynamics

    CERN Document Server

    Dulat, Sayipjamal; Gao, Jun; Guzzi, Marco; Huston, Joey; Nadolsky, Pavel; Pumplin, Jon; Schmidt, Carl; Stump, Daniel; Yuan, C P

    2015-01-01

    We present new parton distribution functions (PDFs) up to next-to-next-to-leading order (NNLO) from the CTEQ-TEA global analysis of quantum chromodynamics. These differ from previous CT PDFs in several respects, including the use of data from LHC experiments and the new D0 charged lepton rapidity asymmetry data, as well as the use of more flexible parametrization of PDFs that, in particular, allows a better fit to different combinations of quark flavors. Predictions for important LHC processes, especially Higgs boson production at 13 TeV, are presented. These CT14 PDFs include a central set and error sets in the Hessian representation. For completeness, we also present the CT14 PDFs determined at the leading order (LO) and the next-to-leading order (NLO) in QCD. Besides these general-purpose PDF sets, we provide a series of (N)NLO sets with various $\\alpha_s$ values and additional sets in heavy-quark scheme with up to 3, 4, and 6 active flavors.

  19. 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

  20. Lattice quantum chromodynamics and properties of the nucleon

    International Nuclear Information System (INIS)

    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

  1. Topological Visualisation techniques for the understanding of Lattice Quantum Chromodynamics (LQCD) simulations

    CERN Document Server

    Thomas, Dean P; Hands, Simon

    2016-01-01

    The use of topology for visualisation applications has become increasingly popular due to its ability to summarise data at a high level. Criticalities in scalar field data are used by visualisation methods such as the Reeb graph and contour trees to present topological structure in simple graph based formats. These techniques can be used to segment the input field, recognising the boundaries between multiple objects, allowing whole contour meshes to be seeded as separate objects. In this paper we demonstrate the use of topology based techniques when applied to theoretical physics data generated from Quantum Chromodynamics simulations, which due to its structure complicates their use. We also discuss how the output of algorithms involved in topological visualisation can be used by physicists to further their understanding of Quantum Chromodynamics.

  2. Parton densities in quantum chromodynamics gauge invariance, path-dependence and Wilson lines

    CERN Document Server

    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.

  3. Verifying Unmatter by Experiments, More Types of Unmatter, and a Quantum Chromodynamics Formula

    Directory of Open Access Journals (Sweden)

    Smarandache F.

    2005-07-01

    Full Text Available As shown, experiments registered unmatter: a new kind of matter whose atoms include both nucleons and anti-nucleons, while their life span was very short, no more than 10^−20 sec. Stable states of unmatter can be built on quarks and anti-quarks: applying the unmatter principle here it is obtained a quantum chromodynamics formula that gives many combinations of unmatter built on quarks and anti-quarks.

  4. Light-Front Quantum Chromodynamics: A framework for the analysis of hadron physics

    CERN Document Server

    Bakker, B L G; Brodsky, S J; Broniowski, W; Dalley, S; Frederico, T; Glazek, S D; Hiller, J R; Ji, C -R; Karmanov, V; Kulshreshtha, D; Mathiot, J -F; Melnitchouk, W; Miller, G A; Papavassiliou, J; Polyzou, W N; Stefanis, N G; Vary, J P; Ilderton, A; Heinzl, T

    2013-01-01

    An outstanding goal of physics is to find solutions that describe hadrons in the theory of strong interactions, Quantum Chromodynamics (QCD). For this goal, the light-front Hamiltonian formulation of QCD (LFQCD) is a complementary approach to the well-established lattice gauge method. LFQCD offers access to the hadrons' nonperturbative quark and gluon amplitudes, which are directly testable in experiments at existing and future facilities. We present an overview of the promises and challenges of LFQCD in the context of unsolved issues in QCD that require broadened and accelerated investigation. We identify specific goals of this approach and address its quantifiable uncertainties.

  5. Scalar quantum chromodynamics in two dimensions and parton model. [Scalar quarks, SU(N) groups

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Quantum chromodynamics

    International Nuclear Information System (INIS)

    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

  7. Quantum Chromodynamics

    Science.gov (United States)

    Fried, H. M.; Müller, B.; Gabellini, Y.

    2000-11-01

    The Table of Contents for the full book PDF is as follows: * Preface * Basic Concepts and Consequences of a Stochastic Vacuum Model * The Role of the QCD Vacuum in the Heavy-Quark Bound State Dynamics * Stochastic Vacuum Model and High Energy Scattering * Variational Approximations for Correlation Functions in Quantum Field Theories * Long-Range Vacuum Correlations? * Unitary Gauge Theories in Singlet Coordinates * SU(2) Gauge Theory in Covariant (Maximal) Abelian Gauges * Dynamics and Topology of the Gauge-Invariant Gauge Field in Two-Color QCD * The Vacuum Wave Function in Supersymmetric Matrix Theory * Analytic Models for the Forward Scattering Amplitude at High Energies * Extending the Frontiers -- Reconciling Accelerator and Cosmic Ray p - p Cross Sections * HERA Results on Elastic Hadronic and Sub-Hadronic Diffraction * Small-x Structure Functions and QCD Pomeron * AdS/CFT Correspondence for QCD and Pomeron Intercept at Strong Coupling * Short Introduction to QGP Dynamics * Effective Theories for Hot Non-Abelian Dynamics * Non-Perturbative Gluodynamics of High Enerry Heavy-Ion Collisions * Deriving Effective Transport Equations for Non-Abelian Plasmas * Ergodic Properties of Non-Abelian Gauge Theories * String from Large Nc Gauge Fields via Graph Summation on a P+ - x+ Lattice * Aspects of Non-Commutativity in ADS/CFT * Eikonal Scattering of Monopoles and Dyons in Dual QED * Gluon Reggeization and Sudakov Suppression via The Fock-Feynman-Schwinger Approach to QCD * Nonperturbative Gluon Radiation and Energy Dependence of Elastic Scattering * Thermal Field Theory in Equilibrium * Puzzling Aspects of Hot Quantum Fields * Color Superconductivity in Cold, Dense Quark Matter * DIS Results from HERA * Electroproduction of Vector Mesons * Probing the QED and QCD Vacua * New Developments in Cosmology * Duality and SU(1,1) coherent states in the Calogero-Moser Model * pp Elastic scattering at LHC and Signature of Chiral Phase Transition at Large |t| * A New Basis Function Approach to 't Hooft Equation * The Heavy Hadron Spectrum and mb from Lattice QCD * Heavy-Light Physics from Lattice NRQCD * Quarkonium Decays and Production in NRQCD * Polarization of Prompt J/ψ at the Tevatron * Non-Relativistic Effective Field Theory for Perturbative Heavy Quark-Antiquark Systems * Accelerating, Storing and Scattering Polarized Protons * Phenomenology of Tlansverse Single Spin Asymmetries in Inclusive Processes * The Spin Dependence of Swift Proton Collisions * Numerical Investigation of Domain-Wall QCD on CP-PACS * New Results for the Spin-Dependent Total Cross Section Difference ΔσL (np) Over the GeV Energy Region * When is it Possible to Use Perturbation Technique in Field Theory? * List of Participants

  8. 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.

  9. Parallelizing the QUDA Library for Multi-GPU Calculations in Lattice Quantum Chromodynamics

    CERN Document Server

    Babich, Ronald; Joó, Bálint

    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.

  10. Particle Formation and Ordering in Strongly Correlated Fermionic Systems: Solving a Model of Quantum Chromodynamics

    CERN Document Server

    Azaria, P; Lecheminant, Ph; Palmai, T; Takacs, G; Tsvelik, A M

    2016-01-01

    In this paper we study a (1+1)-dimensional version of the famous Nambu-Jona-Lasinio model of Quantum Chromodynamics (QCD2) both at zero and finite matter density. We use non-perturbative techniques (non-Abelian bosonization and Truncated Conformal Space Approach). At zero density we describe a formation of fermion three-quark (nucleons and $\\Delta$-baryons) and boson (two-quark mesons, six-quark deuterons) bound states and also a formation of a topologically nontrivial phase. At finite matter density, the model has a rich phase diagram which includes phases with density wave and superfluid quasi-long-range (QLR) order and also a phase of a baryon Tomonaga-Luttinger liquid (strange metal). The QLR order results as a condensation of scalar mesons (the density wave) or six-quark bound states (deuterons).

  11. Quantum Chromodynamics, Antiferromagnets and XY Models from a Unified Point of View

    CERN Document Server

    Hofmann, Christoph P

    2016-01-01

    Antiferromagnets and quantum XY magnets in three space dimensions are described by an effective Lagrangian that exhibits the same structure as the effective Lagrangian of quantum chromodynamics with two light flavors. These systems all share a spontaneously broken internal symmetry O($N$) $\\to$ O($N$-1). Although the respective scales differ by many orders of magnitude, the general structure of the low-temperature expansion of the partition function is the same. In the nonabelian case, logarithmic terms of the form $T^8 \\ln T$ emerge at three-loop order, while for $N$=2 the series only involves powers of $T^2$. The manifestation of the Goldstone boson interaction in the pressure, order parameter, and susceptibility is explored in presence of an external field.

  12. Resonant π^{+}γ→π^{+}π^{0} Amplitude from Quantum Chromodynamics.

    Science.gov (United States)

    Briceño, Raúl A; Dudek, Jozef J; Edwards, Robert G; Shultz, Christian J; Thomas, Christopher E; Wilson, David J

    2015-12-11

    We present the first ab initio calculation of a radiative transition of a hadronic resonance within quantum chromodynamics (QCD). We compute the amplitude for ππ→πγ^{⋆}, as a function of the energy of the ππ pair and the virtuality of the photon, in the kinematic regime where ππ couples strongly to the unstable ρ resonance. This exploratory calculation is performed using a lattice discretization of QCD with quark masses corresponding to m_{π}≈400  MeV. We obtain a description of the energy dependence of the transition amplitude, constrained at 48 kinematic points, that we can analytically continue to the ρ pole and identify from its residue the ρ→πγ^{⋆} form factor. PMID:26705626

  13. Particle formation and ordering in strongly correlated fermionic systems: Solving a model of quantum chromodynamics

    Science.gov (United States)

    Azaria, P.; Konik, R. M.; Lecheminant, P.; Pálmai, T.; Takács, G.; Tsvelik, A. M.

    2016-08-01

    In this paper we study a (1 +1 )-dimensional version of the famous Nambu-Jona-Lasinio model of quantum chromodynamics (QCD2) both at zero and at finite baryon density. We use nonperturbative techniques (non-Abelian bosonization and the truncated conformal spectrum approach). When the baryon chemical potential, μ , is zero, we describe the formation of fermion three-quark (nucleons and Δ baryons) and boson (two-quark mesons, six-quark deuterons) bound states. We also study at μ =0 the formation of a topologically nontrivial phase. When the chemical potential exceeds the critical value and a finite baryon density appears, the model has a rich phase diagram which includes phases with a density wave and superfluid quasi-long-range (QLR) order, as well as a phase of a baryon Tomonaga-Luttinger liquid (strange metal). The QLR order results in either a condensation of scalar mesons (the density wave) or six-quark bound states (deuterons).

  14. Quantum field theory in a magnetic field: From quantum chromodynamics to graphene and Dirac semimetals

    Energy Technology Data Exchange (ETDEWEB)

    Miransky, Vladimir A., E-mail: vmiransk@uwo.ca [Department of Applied Mathematics, Western University, London, Ontario N6A 5B7 (Canada); Shovkovy, Igor A., E-mail: igor.shovkovy@asu.edu [College of Letters and Sciences, Arizona State University, Mesa, AZ 85212 (United States)

    2015-04-30

    A range of quantum field theoretical phenomena driven by external magnetic fields and their applications in relativistic systems and quasirelativistic condensed matter ones, such as graphene and Dirac/Weyl semimetals, are reviewed. We start by introducing the underlying physics of the magnetic catalysis. The dimensional reduction of the low-energy dynamics of relativistic fermions in an external magnetic field is explained and its role in catalyzing spontaneous symmetry breaking is emphasized. The general theoretical consideration is supplemented by the analysis of the magnetic catalysis in quantum electrodynamics, chromodynamics and quasirelativistic models relevant for condensed matter physics. By generalizing the ideas of the magnetic catalysis to the case of nonzero density and temperature, we argue that other interesting phenomena take place. The chiral magnetic and chiral separation effects are perhaps the most interesting among them. In addition to the general discussion of the physics underlying chiral magnetic and separation effects, we also review their possible phenomenological implications in heavy-ion collisions and compact stars. We also discuss the application of the magnetic catalysis ideas for the description of the quantum Hall effect in monolayer and bilayer graphene, and conclude that the generalized magnetic catalysis, including both the magnetic catalysis condensates and the quantum Hall ferromagnetic ones, lies at the basis of this phenomenon. We also consider how an external magnetic field affects the underlying physics in a class of three-dimensional quasirelativistic condensed matter systems, Dirac semimetals. While at sufficiently low temperatures and zero density of charge carriers, such semimetals are expected to reveal the regime of the magnetic catalysis, the regime of Weyl semimetals with chiral asymmetry is realized at nonzero density. Finally, we discuss the interplay between relativistic quantum field theories (including quantum

  15. On the usefulness of the 't Hooft and Adler transformations of the running coupling constant in perturbative quantum chromodynamics

    International Nuclear Information System (INIS)

    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.)

  16. Demonstration of string breaking in quantum chromodynamics by large-scale eigenvalue computations

    Science.gov (United States)

    Attig, N.; Bali, G. S.; Düssel, Th.; Lippert, Th.; Neff, H.; Prkaçin, Z.; Schilling, K.

    2005-07-01

    We present results of our ongoing determination of "string breaking" in quantum chromodynamics (QCD) including two dynamical light quarks. Our investigation of the fission of the string between a heavy (static) quark and a corresponding antiquark into a meson-antimeson system is based on dynamical configurations of size 24×40. The all-to-all light quark propagators occurring in the transition element are computed from a set of 200 low-lying eigenmodes of the Hermitian Wilson-Dirac matrix which encodes the effect of the dynamical quarks. These eigenmodes are calculated on the 1312-node IBM p690 system at the John von Neumann Institute in Jülich. Combining the eigenvalue computations with a variety of ground state enhancing optimization methods we determine the matrix elements of the two-by-two system with so far unprecedented accuracy. We observe—for the first time ever in a simulation of 4-dimensional lattice-QCD— level-splitting as the perfect signature for dynamical string breaking between ground state and excited potential.

  17. Net-proton measurements at RHIC and the quantum chromodynamics phase diagram

    Indian Academy of Sciences (India)

    Bedangadas Mohanty

    2014-11-01

    Two measurements related to the proton and antiproton production near midrapidity in $\\sqrt{s_{NN}}$ = 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV Au+Au collisions using the STAR detector at the Relativistic Heavy Ion Collider (RHIC) are discussed. At intermediate impact parameters, the net-proton midrapidity d$v_1$/d, where $v_1$ and are directed flow and rapidity, respectively, shows non-monotonic variation as a function of beam energy. This non-monotonic variation is characterized by the presence of a minimum in d$v_1$/d between $\\sqrt{s_{NN}}$ = 11.5 and 19.6 GeV and a change in the sign of d$v_1$/d twice between $\\sqrt{s_{NN}}$ = 7.7 and 39 GeV. At small impact parameters the product of the moments of net-proton distribution, kurtosis × variance ( 2) and skewness × standard deviation ($S$) are observed to be significantly below the corresponding measurements at large impact parameter collisions for $\\sqrt{s_{NN}}$ = 19.6 and 27 GeV. The 2 and $S$ values at these beam energies deviate from the expectations from Poisson statistics and that from a hadron resonance gas model. Both these measurements have implications towards understanding the quantum chromodynamics (QCD) phase structures, the first-order phase transition and the critical point in the high baryonic chemical potential region of the phase diagram.

  18. 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.

  19. Strongly correlated quantum fluids: ultracold quantum gases, quantum chromodynamic plasmas and holographic duality

    Science.gov (United States)

    Adams, Allan; Carr, Lincoln D.; Schäfer, Thomas; Steinberg, Peter; Thomas, John E.

    2012-11-01

    Strongly correlated quantum fluids are phases of matter that are intrinsically quantum mechanical and that do not have a simple description in terms of weakly interacting quasiparticles. Two systems that have recently attracted a great deal of interest are the quark-gluon plasma, a plasma of strongly interacting quarks and gluons produced in relativistic heavy ion collisions, and ultracold atomic Fermi gases, very dilute clouds of atomic gases confined in optical or magnetic traps. These systems differ by 19 orders of magnitude in temperature, but were shown to exhibit very similar hydrodynamic flows. In particular, both fluids exhibit a robustly low shear viscosity to entropy density ratio, which is characteristic of quantum fluids described by holographic duality, a mapping from strongly correlated quantum field theories to weakly curved higher dimensional classical gravity. This review explores the connection between these fields, and also serves as an introduction to the focus issue of New Journal of Physics on ‘Strongly Correlated Quantum Fluids: From Ultracold Quantum Gases to Quantum Chromodynamic Plasmas’. The presentation is accessible to the general physics reader and includes discussions of the latest research developments in all three areas.

  20. Simulation of quantum chromodynamics on the lattice with exactly chiral lattice fermions

    Science.gov (United States)

    Aoki, Sinya; Chiu, Ting-Wai; Cossu, Guido; Feng, Xu; Fukaya, Hidenori; Hashimoto, Shoji; Hsieh, Tung-Han; Kaneko, Takashi; Matsufuru, Hideo; Noaki, Jun-Ichi; Onogi, Tetsuya; Shintani, Eigo; Takeda, Kouhei

    2012-09-01

    Numerical simulation of the low-energy dynamics of quarks and gluons is now feasible based on the fundamental theory of strong interaction, i.e. quantum chromodynamics (QCD). With QCD formulated on a 4D hypercubic lattice (called lattice QCD or LQCD), one can simulate the QCD vacuum and hadronic excitations on the vacuum using teraflop-scale supercomputers, which have become available in the last decade. A great deal of work has been done on this subject by many groups around the world; in this article we summarize the work done by the JLQCD and TWQCD collaborations since 2006. These collaborations employ Neuberger's overlap fermion formulation, which preserves the exact chiral and flavor symmetries on the lattice, unlike other lattice fermion formulations. Because of this beautiful property, numerical simulation of the formulation can address fundamental questions on the QCD vacuum, such as the microscopic structure of the quark-antiquark condensate in the chirally broken phase of QCD and its relation to SU(3) gauge field topology. Tests of the chiral effective theory, which is based on the assumption that the chiral symmetry is spontaneously broken in the QCD vacuum, can be performed, including the pion-loop effect test. For many other phenomenological applications, we adopt the all-to-all quark propagator technique, which allows us to compute various correlation functions without substantial extra cost. The benefit of this is not only that the statistical signal is improved but that disconnected quark-loop diagrams can be calculated. Using this method combined with the overlap fermion formulation, we study a wide range of physical quantities that are of both theoretical and phenomenological interest.

  1. Form factors and charge radii in a quantum chromodynamics-inspired potential model using variationally improved perturbation theory

    International Nuclear Information System (INIS)

    We use variationally improved perturbation theory (VIPT) for calculating the elastic form factors and charge radii of D, Ds, B, Bs and Bc 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 Q2, hinting at a workable range of Q2 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)

  2. Probing Quantum Chromodynamics with the ATLAS Detector: Charged-Particle Event Shape Variables and the Dijet Cross-Section

    CERN Document Server

    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...

  3. Form factors and charge radii in a quantum chromodynamics-inspired potential model using variationally improved perturbation theory

    Indian Academy of Sciences (India)

    Bhaskar Jyoti Hazarika; D K choudhury

    2015-01-01

    We use variationally improved perturbation theory (VIPT) for calculating the elastic form factors and charge radii of , $D_{s}$, $B$, $B_{s}$ 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 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.

  4. High energy deep inelastic scattering in perturbative quantum chromodynamics; Diffusion profondement inelastique a grande energie en chromodynamique quantique perturbative

    Energy Technology Data Exchange (ETDEWEB)

    Wallon, S.

    1996-09-17

    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). 120 refs.

  5. Study Of Spin-dependent Masses And Configuration Mixings In Heavy Quarkonia And Hybrids Using Lattice Nonrelativistic Quantum Chromodynamics

    CERN Document Server

    Burch, T

    2003-01-01

    While we may know the overall quantum numbers of a given meson state and that such a state is necessarily a color singlet, we do not know a priori the relative spin and color alignments of the constituents: the quarks, antiquarks, and gluons. The overall meson wavefunction may have contributions from different spin- color configurations: one where the quark and antiquark alone account for the spin of the meson; or another where a gluon excitation also contributes to the total spin (a hybrid state), while helping to form the color singlet. The determination of the relative contributions of each these configurations to the overall meson state is the focus of this work. We use the lattice formulation of quantum chromodynamics (QCD) and we restrict our analysis to the limit of heavy quark masses. We are therefore able to use a non- relativistic approximation for the quark and antiquark Hamiltonians (NRQCD). This provides the additional separation of the spin- and orbital-angular-momentum degrees of freedom of the...

  6. Perturbative quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    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/sup +/e/sup -/..-->..had//sigma/sub e/sup +/e/sup -/..--> mu../sup +/..mu../sup -//, 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. (RWR)

  7. Perturbative quantum chromodynamics

    International Nuclear Information System (INIS)

    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

  8. Beyond standard quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Lattice Quantum Chromodynamics

    Science.gov (United States)

    Sachrajda, C. T.

    2016-10-01

    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.

  10. Quantum Chromodynamics: Computational Aspects

    CERN Document Server

    Schaefer, Thomas

    2016-01-01

    We present a brief introduction to QCD, the QCD phase diagram, and non-equilibrium phenomena in QCD. We emphasize aspects of the theory that can be addressed using computational methods, in particular euclidean path integral Monte Carlo, fluid dynamics, kinetic theory, classical field theory and holographic duality.

  11. Quantum Chromodynamics (abstract only)

    NARCIS (Netherlands)

    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 stro

  12. Lattice Quantum Chromodynamics

    CERN Document Server

    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.

  13. Testing quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Testing quantum chromodynamics

    International Nuclear Information System (INIS)

    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

  15. Probing quantum chromodynamics with the ATLAS detector. Charged-particle event shape variables and the dijet cross-section

    Energy Technology Data Exchange (ETDEWEB)

    Huelsing, Tobias

    2015-01-22

    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{sup 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 √(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 shapes are studied: The transverse thrust, the thrust minor and the transverse sphericity. Data recorded during low pile-up beam conditions in early 2010, corresponding to an integrated luminosity of 168 μb, is analyzed. Charged particles with a transverse momentum above 500 MeV are used to compute the event shape variables. In addition to differential event shape distributions in p{sub T} of the highest-transverse-momentum particle, the evolution of each event shape variable as a function of charged particle multiplicity and summed transverse momentum is presented. Predictions from different Monte Carlo models are compared with data and they show significant deviations from data. Using the results to tune the free parameters of the phenomenological models can improve future Monte Carlo predictions and give additional insight to the non-perturbative part of the QCD. The measurement of the double-differential dijet cross section as function of the dijet mass and

  16. Quantum chromodynamics at high energy, theory and phenomenology at hadron colliders; Chromodynamique quantique a haute energie, theorie et phenomenologie appliquee aux collisions de hadrons

    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)

  17. Chiral and deconfinement phase transitions in N{sub f}=2 and N{sub f}=2+1 quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Luecker, Jan

    2013-07-15

    In this thesis, we investigate the phase structure of quantum chromodynamics (QCD) in the framework of Dyson-Schwinger equations (DSEs). The aim is to study the chiral and deconfinement phase transitions at finite chemical potential. To this end, we employ and test a novel truncation scheme for the quark and gluon Dyson-Schwinger equations. We develop our truncation in three steps. To begin with, we use a quenched gluon propagator from lattice Yang-Mills theory. To account for unquenching, we then add the quark loop in the gluon DSE, firstly with bare quarks and in the final version of our truncation with fully dressed quarks. In the last step it is also possible to take into account the coupling of light and strange quarks. In effective models, fermionic fluctuations have been shown to move the critical end-point to large densities. We confirm this finding within our truncation for the unquenched gluon. However, this effect is suppressed once the full non-perturbative quark in the quark loop is taken into account. For the confinement/deconfinement transition we investigate three order parameters that are accessible from the quark and gluon propagators. These are the dressed Polyakov loop, the Polyakov-loop potential and positivity violations in the quark propagator. From both Polyakov-loop related order parameters, we find that the deconfinement transition can always be found in vicinity of the chiral transition. Especially at the critical end-point the phase transitions coincide. We also find that signals of positivity violations in the quark propagator vanish at the chiral transition for the two-flavour case. However, with 2+1 flavours, we find a region at large density where chiral symmetry is restored but positivity is violated. This requires further investigations. Finally, we improve our truncation by considering the back-reaction of pions in a model that has been developed in previous work. Within this model we find only a small impact on the phase

  18. Exclusive processes in quantum chromodynamics

    International Nuclear Information System (INIS)

    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

  19. Quantum chromodynamics at hadron colliders

    Indian Academy of Sciences (India)

    Vittorio Del Duca

    2006-11-01

    QCD is an extensively developed and tested gauge theory, which models the strong interactions in the high-energy regime. In this talk, I shall review the considerable progress which has been achieved in the last few years in the most actively studied QCD topics: Monte Carlo models, higher-order corrections, and parton distribution functions. Thanks to that, QCD in the high-energy regime is becoming more and more an essential precision tool kit to analyse Higgs and new physics scenarios at the LHC.

  20. Polarization phenomena in quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    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{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 helicity 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. 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{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.

  1. Working group report: Quantum chromodynamics

    Indian Academy of Sciences (India)

    V Ravindra; Pankaj Agrawal; Rahul Basu; Satyaki Bhattacharya; J Blümlein; V Del Duca; R Harlander; D Kosower; Prakash Mathews; Anurag Tripathi

    2006-11-01

    This is the report of the subgroup QCD of Working Group-4 at WHEPP-9. We present the activities that had taken place in the subgroup and report some of the partial results arrived at following the discussion at the working group meetings.

  2. Quantum chromodynamics at high energy

    CERN Document Server

    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.

  3. Phase transitions in quantum chromodynamics

    CERN Document Server

    Meyer-Ortmanns, H

    1996-01-01

    The current understanding of finite temperature phase transitions in QCD is reviewed. A critical discussion of refined phase transition criteria in numerical lattice simulations and of analytical tools going beyond the mean-field level in effective continuum models for QCD is presented. Theoretical predictions about the order of the transitions are compared with possible experimental manifestations in heavy-ion collisions. Various places in phenomenological descriptions are pointed out, where more reliable data for QCD's equation of state would help in selecting the most realistic scenario among those proposed. Unanswered questions are raised about the relevance of calculations which assume thermodynamic equilibrium. Promising new approaches to implement nonequilibrium aspects in the thermodynamics of heavy-ion collisions are described.

  4. Measurement of the lepton {tau} spectral functions and applications to quantum chromodynamic; Mesure des fonctions spectrales du lepton {tau} et applications a la chromodynamique quantique

    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

  5. Hadronic distributions and correlations at 'small x' in quantum chromodynamics; Distributions et correlations hadroniques en chromodynamique quantique dans l'approximation des 'petit X'

    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)

  6. Study of the meson mass spectroscopy with a potential model inspired in the quantum chromodynamics; Estudo da espectroscopia de massas de mesons segundo um modelo de potencial inspirado em cromodinamica quantica

    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)

  7. 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.)

  8. Light-cone quantization of quantum chromodynamics

    International Nuclear Information System (INIS)

    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

  9. Introduction to quantum chromodynamics at hadron colliders

    Indian Academy of Sciences (India)

    William B Kilgore

    2011-05-01

    A basic introduction to the application of QCD at hadron colliders is presented. I briefly review the phenomenological and theoretical origins of QCD, and then discuss factorization and infrared safety, parton distributions, the computation of hard scattering amplitudes and applications of perturbative QCD.

  10. On de-globalization in quantum chromodynamics

    Indian Academy of Sciences (India)

    Mrinal Dasgupta

    2004-03-01

    The recent discovery and resummation of a class of single logarithmic effects (non-global logs), has a significant impact on several QCD observables ranging from the classic Sterman-Weinberg jet definition to currently studied event shapes and rapidity gap observables. The discovery of the above effects overturns, for example, the common wisdom that hadronic energy flow in limited inter-jet regions is dictated primarily by the colour flow of the underlying hard partonic subprocess. We discuss some features of non-global logs and the rapid progress being made in estimating and controlling such corrections.

  11. On de-globalization in quantum chromodynamics

    International Nuclear Information System (INIS)

    The recent discovery and resummation of a class of single logarithmic effects (non-global logs), has a significant impact on several QCD observables ranging from the classic Sterman-Weinberg jet definition to currently studied event shapes and rapidity gap observables. The discovery of the above effects overturns, for example, the common wisdom that hadronic energy flow in limited inter-jet regions is dictated primarily by the colour flow of the underlying hard partonic subprocess. We discuss some features of non-global logs and the rapid progress being made in estimating and controlling such corrections. (author)

  12. Quantum chromodynamics results from HERA and JLAB

    Indian Academy of Sciences (India)

    Katja Krüger

    2012-10-01

    Recent QCD results from electron–proton interactions at HERA and JLAB are presented. Inclusive cross-section measurements as well as studies of the hadronic final state like jet production or the production of heavy quarks are discussed. The results are compared with perturbative QCD predictions and their impact on the determination of the parton density functions of the proton as well as of the strong coupling α s is discussed.

  13. Calculations in external fields in quantum chromodynamics

    International Nuclear Information System (INIS)

    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

  14. Quantum Chromodynamics and Deep Inelastic Scattering

    Science.gov (United States)

    Ellis, R. Keith

    2016-10-01

    This article first describes the parton model which was the precursor of the QCD description of hard scattering processes. After the discovery of QCD and asymptotic freedom, the first successful applications were to Deep Inelastic lepton-hadron scattering. The subsequent application of QCD to processes with two initial state hadrons required the understanding and proof of factorization. To take the fledgling theory and turn it into the robust calculational engine it has become today, required a number of technical and conceptual developments which will be described. Prospects for higher loop calculations are also reviewed.

  15. Quantum Chromodynamics and Deep Inelastic Scattering

    CERN Document Server

    Keith Ellis, R

    2016-01-01

    This article first describes the parton model which was the precursor of the QCD description of hard scattering processes. After the discovery of QCD and asymptotic freedom, the first successful applications were to Deep Inelastic lepton-hadron scattering. The subsequent application of QCD to processes with two initial state hadrons required the understanding and proof of factorization. To take the fledgling theory and turn it into the robust calculational engine it has become today, required a number of technical and conceptual developments which will be described. Prospects for higher loop calculations are also reviewed.

  16. 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.

  17. Quantum chromodynamics (QCD) and collider physics

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, R.K. (Fermi National Accelerator Lab., Batavia, IL (USA)); Stirling, W.J. (Durham Univ. (UK))

    1990-08-14

    This report discusses: fundamentals of perturbative QCD; QCD in e{sup +}e{sup {minus}} {yields} hadrons; deep inelastic scattering and parton distributions; the QCD parton model in hadron-hadron collisions; large p{sub T} jet production in hadron-hadron collisions; the production of vector bosons in hadronic collisions; and the production of heavy quarks.

  18. Meson spectroscopy, quark mixing and quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Filippov, A.T.

    1979-04-01

    A semiphenomenological theory of the quark-antiquark meson mass spectrum is presented. Relativistic kinematic effects due to unequal quark masses and SU (3) -breaking effects in the slopes of Regge trajectories and in radially excited states are taken into account. Violation of the OZI rule is accounted for by means of a mixing matrix for the quark wave functions, which is given by QCD. To describe the dependence of the mixing parameters on the meson masses, a simple extrapolation of the QCD expressions is proposed from the ''asymptotic-freedom'' region to the ''infrared-slavery'' region. To calculate the masses and mixing angles of the pseudoscalar mesons, the condition for a minimal pion mass is proposed. The eta-meson mass is then shown to be close to its maximum. The predictions of the theory for meson masses and mixing angles are in good agreement with experiment.

  19. Quantum chromodynamics near the confinement limit

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. 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.)

  1. Case studies in perturbative quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. From Moments to Functions in Quantum Chromodynamics

    CERN Document Server

    Blümlein, J; Klein, S; Schneider, C

    2009-01-01

    Single-scale quantities, like the QCD anomalous dimensions and Wilson 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.

  3. On de-globalization in quantum chromodynamics

    CERN Document Server

    Das-Gupta, M

    2004-01-01

    The recent discovery and resummation of a class of single-logarithmic effects (non-global logs), has a significant impact on several QCD observables ranging from the classic Sterman-Weinberg jet definition to currently studied event shapes and rapidity gap observables. The discovery of the above effects overturns, for example, the common wisdom that hadronic energy flow in limited interjet regions is dictated primarily by the colour flow in the underlying hard partonic subprocess. We discuss some features of non-global logs and the rapid progress being made in estimating and controlling such corrections.

  4. Lattice quantum chromodynamics with approximately chiral fermions

    International Nuclear Information System (INIS)

    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.)

  5. Quark Confinement Physics from Quantum Chromodynamics

    CERN Document Server

    Suganuma, H; Tanaka, A; Ichie, H

    2016-01-01

    We show the construction of the dual superconducting theory for the confinement mechanism from QCD in the maximally abelian (MA) gauge using the lattice QCD Monte Carlo simulation. We find that essence of infrared abelian dominance is naturally understood with the off-diagonal gluon mass $m_{\\rm off} \\simeq 1.2 {\\rm GeV}$ induced by the MA gauge fixing. In the MA gauge, the off-diagonal gluon amplitude is forced to be small, and the off-diagonal gluon phase tends to be random. As the mathematical origin of abelian dominance for confinement, we demonstrate that the strong randomness of the off-diagonal gluon phase leads to abelian dominance for the string tension. In the MA gauge, there appears the macroscopic network of the monopole world-line covering the whole system. We investigate the monopole-current system in the MA gauge by analyzing the dual gluon field $B_\\mu$. We evaluate the dual gluon mass as $m_B = 0.4 \\sim$ 0.5GeV in the infrared region, which is the lattice-QCD evidence of the dual Higgs mechan...

  6. Quantum chromodynamics studies at LEP2

    Indian Academy of Sciences (India)

    Sunanda Banerjee

    2000-07-01

    Several studies have been made to the hadronic final states in +- collisions at LEP. Studies of the annihilation process at LEP2 have given rise to results on jet rate, event shape, heavy flavour production, inclusive momentum spectra, Bose–Einstein correlation and colour reconnection effects. Event shape studies have given rise to accurate determination of the strong coupling constant s using $\\mathcal{O}(^{2}_{s})$ with resummed leading and next-to-leading log calculation and also with power law corrections. Studies of 2-photon processes have yielded results on cross-section, heavy flavour production, photon structure function and ** scattering.

  7. Understanding QCD [Quantum Chromodynamics] at colliders

    International Nuclear Information System (INIS)

    We examine Drell-Yan μ-pair production and heavy quark pair production, and demonstrate how to implement precise comparisons between the theoretical predictions of QCD and the experimental observables. Specifically, we have dealt with theoretical uncertainties arising from higher order corrections, unknown small-χ behavior, and the unknown gluon distribution. We indicate how the above processes can provide discriminating tests of the theory in the kinematic regimes which will soon be investigated by the Tevatron I and HERA facilities. 8 refs., 6 figs

  8. Large- quantum chromodynamics and harmonic sums

    Indian Academy of Sciences (India)

    Eduardo De Rafael

    2012-06-01

    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 discussed.

  9. Higher order corrections in perturbative quantum chromodynamics

    Indian Academy of Sciences (India)

    W L Van Neerven

    2000-07-01

    We present some techniques which have been developed recently or in the recent past to compute Feynman graphs beyond one-loop order. These techniques are useful to compute the three-loop splitting functions in QCD and to obtain the complete second order QED corrections to Bhabha scattering.

  10. Quantum chromodynamics near the confinement limit

    International Nuclear Information System (INIS)

    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

  11. 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.)

  12. Quantum chromodynamics in hadron collider experiments: towards automated one-loop calculations for multi-particle processes. Application to the production of 2 photons and 1 jet; Chromodynamique quantique aux collisionneurs hadroniques: vers une automatisation du calcul des processus multi-particules a l'ordre d'une boucle. Application a la production de deux photons et un jet

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoudi, F

    2004-06-01

    The future CERN collider (LHC) has a fantastic potential of discovery, provided quantum chromodynamics can be quantitatively predicted. To do so, it is necessary to work at NLO approximation in order to reduce the dependence of the -cross-section on- the non-physical scales. To obtain results in this approximation, one has to calculate the cross-sections of the partonic subprocesses contributing to the studied reaction at the lowest order, and also the virtual corrections (loop corrections) and the real corrections. The calculation of the virtual corrections remains very complicated if the number of external particles is greater than four or if the external (internal) particles are massive. in this thesis, an automatic method which enables to calculate one loop diagrams with five external legs and which can be generalized to the case of massive particles is presented. In a first part, we describe different tools and methods necessary to such calculations. We then apply -them to the calculation of the gg {yields}{gamma}{gamma} g reaction, which interests the ATLAS and CMS experimentalists as the background for the Higgs boson search. We also give the explicit result for this amplitude for each helicity configuration in a compact form and a clearly gauge invariant representation. We finally present a phenomenological study of this reaction. (author)

  13. Photon pairs: Quantum chromodynamics continuum and the Higgs boson

    Indian Academy of Sciences (India)

    Edmond L Berger

    2007-11-01

    A new QCD calculation is summarized for the transverse momentum distribution of photon pairs produced by QCD subprocesses, including all-orders soft-gluon resummation valid at next-to-next-to-leading logarithmic accuracy. 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 signal at the LHC.

  14. The critical point of quantum chromodynamics through lattice and experiment

    Indian Academy of Sciences (India)

    Sourendu Gupta

    2011-05-01

    This talk discusses methods of extending lattice computations at finite temperature into regions of finite chemical potential, and the conditions under which such results from the lattice may be compared to experiments. Such comparisons away from a critical point are absolutely essential for quantitative use of lattice QCD in heavy-ion physics. An outline of various arguments which can then be used to locate the critical point is also presented.

  15. Dual Higgs Theory for Color Confinement in Quantum Chromodynamics

    CERN Document Server

    Ichie, H; Ichie, Hiroko; Suganuma, Hideo

    1999-01-01

    Based on the dual superconductor picture, we study the confinement phenomena systematically, using the lattice QCD, the monopole-current dynamics and the dual Ginzburg-Landau (DGL) theory. (1) We study the origin of abelian dominance for the confinement force in the maximally abelian (MA) gauge in terms of the gluon-field properties using the lattice QCD. In the MA gauge, the off-diagonal gluon amplitude is strongly suppressed, and the off-diagonal gluon phase tends to be random, according to the weakness of the constraint from the QCD action. Within the random-variable approximation for the off-diagonal gluon phase, we show the perimeter law of the off-diagonal gluon contribution to the Wilson loop, i.e. abelian dominance for the string tension, in the semi-analytical manner. (2) We study the QCD-monopole structure in terms of the gluon field, using the lattice QCD in the MA gauge. Around the monopole, both abelian and off-diagonal parts of the QCD action become large, however, due to the cancellation betwee...

  16. Inclusive and Exclusive Compton Processes in Quantum Chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Psaker, Ales [Old Dominion Univ., Norfolk, VA (United States)

    2005-12-01

    In our work, we describe two types of Compton processes. As an example of an inclusive process, we consider the high-energy photoproduction of massive muon pairs off the nucleon. We analyze the process in the framework of the QCD parton model, in which the usual parton distributions emerge as a tool to describe the nucleon in terms of quark and gluonic degrees of freedom. To study its exclusive version, a new class of phenomenological functions is required, namely, generalized parton distributions. They can be considered as a generalization of the usual parton distributions measured in deeply inelastic lepton-nucleon scattering. Generalized parton distributions (GPDs) may be observed in hard exclusive reactions such as deeply virtual Compton scattering. We develop an extension of this particular process into the weak interaction sector. We also investigate a possible application of the GPD formalism to wide-angle real Compton scattering.

  17. Connections between quantum chromodynamics and condensed matter physics

    Indian Academy of Sciences (India)

    Shailesh Chandrasekharan

    2003-11-01

    Features of QCD can be seen qualitatively in certain condensed matter systems. Recently some of the analyses that originated in condensed matter physics have found applications in QCD. 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 the two fields are quite similar. We argue that recent algorithmic developments call for optimism in both fields.

  18. Inclusive and Exclusive Compton Processes in Quantum Chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Ales Psaker

    2005-12-31

    In our work, we describe two types of Compton processes. As an example of an inclusive process, we consider the high-energy photoproduction of massive muon pairs off the nucleon. We analyze the process in the framework of the QCD parton model, in which the usual parton distributions emerge as a tool to describe the nucleon in terms of quark and gluonic degrees of freedom. To study its exclusive version, a new class of phenomenological functions is required, namely, generalized parton distributions. They can be considered as a generalization of the usual parton distributions measured in deeply inelastic lepton-nucleon scattering. Generalized parton distributions (GPDs) may be observed in hard exclusive reactions such as deeply virtual Compton scattering. We develop an extension of this particular process into the weak interaction sector. We also investigate a possible application of the GPD formalism to wide-angle real Compton scattering.

  19. Fermions in light front transverse lattice quantum chromodynamics

    Indian Academy of Sciences (India)

    Dipankar Chakrabarti; Asit K De; A Harindranath

    2003-11-01

    We briefly describe motivations for studying transverse lattice QCD. Presence of constraint equation for fermion field on the light front allows different methods to put fermions on a transverse lattice. We summarize our numerical investigation of two approaches using (a) forward and backward derivatives and (b) symmetric derivatives.

  20. Mechanical analog for a quantum-chromodynamic phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Salomone, A.; Schechter, J.

    1982-07-15

    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.

  1. Sign-posting the phase diagram of quantum chromodynamics

    Indian Academy of Sciences (India)

    Sourendu Gupta

    2012-10-01

    The good agreement between lattice predictions and data for the shape of the distribution of event-by-event fluctuations of the baryon number is discussed. Such comparisons can give fine probes of thermalization, and can be used to provide a direct determination of the cross-over temperature c QCD. The logic of these comparisons and the systematics involved are discussed. The same methods can be used to further explore the phase diagram.

  2. Testing quantum chromodynamics in anti-proton reactions

    International Nuclear Information System (INIS)

    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

  3. Quantum chromodynamics and hadronic interactions at short distances

    International Nuclear Information System (INIS)

    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

  4. Quantum chromodynamics with infinite number of vector mesons

    International Nuclear Information System (INIS)

    It is supposed that families of vector mesons ρ, ψ, Υ contain an infinite number of resonances with gradually increasing widths. The asymptotic freedom requirement involves a relationship between the electronic width of a resonance and its mass derivative over the number. Using of this relationship it is shown that for the families of ψ and Υ mesons the moment from experimental function R(s)is egual to the sum of the moment from a bare quark loop and the edge term which arised 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 considered resonances and the ρ-meson mass are calculated

  5. 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.

  6. Quantum Chromodynamics and nuclear physics at extreme energy density

    International Nuclear Information System (INIS)

    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

  7. Quantum Chromodynamics and Other Field Theories on the Light Cone

    OpenAIRE

    Brodsky, S.; Pauli, H-C; Pinsky, S.

    1997-01-01

    We discuss the light-cone quantization of gauge theories 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 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 we...

  8. Lattice quantum chromodynamics equation of state: A better differential method

    Indian Academy of Sciences (India)

    Rajiv V Gavai; Sourendu Gupta; Swagato Mukherjee

    2008-09-01

    We propose a better differential method for the computation of the equation of state of QCD from lattice simulations. In contrast to the earlier differential method, our technique yields positive pressure for all temperatures including the temperatures in the transition region. Employing it on temporal lattices of 8, 10 and 12 sites and by extrapolating to zero lattice spacing we obtained the pressure, energy density, entropy density, specific heat and speed of sound in quenched QCD for 0.9 ≤ /c ≤ 3. At high temperatures comparisons of our results are made with those from the dimensional reduction approach and also with those from a conformal symmetric theory.

  9. Topological String in Quantum-Chromodynamical Chiral Phase Transitions

    Institute of Scientific and Technical Information of China (English)

    LI Yun-De

    2005-01-01

    @@ It is pointed out that if in heavy ion collision processes, the quark-gluon plasma SU(2) chiral phase transition really takes place and the phase transition is a second order. Then the topological string, i.e., the π string, will be formed. The main effect of this phenomenon is that there will be a number of pions produced by decay of the π string in the final state. The pions from the decay of the π string lead to the same effect of decreasing the Hanbury-Brown-Twiss peak in two-pion spectra which is just as that of the long-lived hadronic resonances.At relativistic heavy-ion collision and large hadron collision energies, it is expected that the factors are about α~ 0.7 - 0.9 and α~ 0.6 - 0.85, respectively.

  10. Precision tests of quantum chromodynamics and the standard model

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Transverse spin and momentum correlations in quantum chromodynamics

    Indian Academy of Sciences (India)

    Leonard P Gamberg

    2009-01-01

    The naive time reversal odd (`T-odd') parton distribution and fragmentation functions are explored. We use the spectator model framework to study flavour dependence of the Boer–Mulders $(h_{1}^{⊥})$ and Sivers $(f_{1\\text{T}}^{⊥})$ functions as well as the `T-even' but chiral odd function $h_{1\\text{L}}^{⊥}$. These transverse momentum-dependent parton distribution functions are of significance for the analysis of azimuthal asymmetries in semi-inclusive deep inelastic scattering, as well as for the overall physical understanding of the distribution of transversely polarized quarks in unpolarized hadrons. In this context we also consider the Collins mechanism and the fragmentation function $H_{1}^{⊥}$. As a by-product of this analysis we calculate the leading twist unpolarized cos(2) asymmetry, and sin(2) single spin asymmetry for a longitudinally polarized target in semi-inclusive deep inelastic scattering.

  12. Open flavour charmed mesons in a quantum chromodynamics potential model

    Indian Academy of Sciences (India)

    Krishna Kingkar Pathak; D K Choudhury

    2012-12-01

    We modify the mesonic wave function by using a short distance scale 0 in analogy with hydrogen atom and estimate the values of masses and decay constants of the open flavour charm mesons , $D_{s}$ and $B_{c}$ within the framework of a QCD potential model. We also calculate leptonic decay widths of these mesons to study branching ratios and lifetime. The results are in good agreement with experimental and other theoretical values.

  13. Bag-model quantum chromodynamics for hyperons at low energy

    International Nuclear Information System (INIS)

    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.)

  14. Bag-model quantum chromodynamics for hyperons at low energy

    Science.gov (United States)

    Weber, H. J.; Maslow, J. N.

    1980-09-01

    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.

  15. Quantum chromodynamics and deep inelastic e - N scattering at TRISTAN

    International Nuclear Information System (INIS)

    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)

  16. 19th High-Energy Physics International Conference in Quantum Chromodynamics (QCD)

    CERN Document Server

    2016-01-01

    Experimental and Theoretical Issues on: Perturbative and Non-Perturbative QCD QCD at colliders Tau, Kaon and B decays, CP-violation Exotic Hadrons Spectroscopy Precision Tests of the Standard Model Physics Beyond the Standard Model.

  17. Quenched Chiral Logarithm Diverge in Very Light Quark Region from the Overlap Lattice Quantum Chromodynamics

    Institute of Scientific and Technical Information of China (English)

    应和平; 董绍静; 张剑波

    2003-01-01

    With an exact chiral symmetry, overlap fermions allow us to reach very light quark region. In the minimummps = 179 MeV, the quenched chiral logarithm diverge is examined. The chiral logarithm parameter δ is calculatedfrom both the pseudo-scalar meson mass mp2s diverge channel and the pseudo-scalar decay constant f p channel.In both the cases, we obtain δ = 0.25 ± 0.03. We also observe that the quenchedchiral logarithm diverge occursonly in the mps ≤400 MeV region.

  18. Quantum chromodynamics phase transition in the early Universe and quark nuggets

    Indian Academy of Sciences (India)

    Abhijit Bhattacharyya; Shibaji Banerjee; Sanjay K Ghosh; Sibaji Raha; Bikash Sinha; Hiroshi Toki

    2003-05-01

    A first-order quark hadron phase transition in the early Universe may lead to the formation of quark nuggets. The baryon number distribution of these 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$M_{\\odot}$ to 0.12$M_{\\odot}$. It has been discussed that these bigger objects can be possible candidates for cold dark matter.

  19. Strongly Correlated Quantum Fluids: Ultracold Quantum Gases, Quantum Chromodynamic Plasmas, and Holographic Duality

    CERN Document Server

    Adams, Allan; Schaefer, Thomas; Steinberg, Peter; Thomas, John E

    2012-01-01

    Strongly correlated quantum fluids are phases of matter that are intrinsically quantum mechanical, and that do not have a simple description in terms of weakly interacting quasi-particles. Two systems that have recently attracted a great deal of interest are the quark-gluon plasma, a plasma of strongly interacting quarks and gluons produced in relativistic heavy ion collisions, and ultracold atomic Fermi gases, very dilute clouds of atomic gases confined in optical or magnetic traps. These systems differ by more than 20 orders of magnitude in temperature, but they were shown to exhibit very similar hydrodynamic flow. In particular, both fluids exhibit a robustly low shear viscosity to entropy density ratio which is characteristic of quantum fluids described by holographic duality, a mapping from strongly correlated quantum field theories to weakly curved higher dimensional classical gravity. This review explores the connection between these fields, and it also serves as an introduction to the Focus Issue of N...

  20. Polyakov loop and the color-flavor locked phase of Quantum Chromodynamics

    CERN Document Server

    Ciminale, M; Ruggieri, M; Gatto, R

    2007-01-01

    We consider the Polyakov Nambu Jona Lasinio model with three massless quarks at high density and moderate temperature in the superconductive color flavor locking phase. We compute the critical temperature $T_c$ as a function of the baryonic chemical potential for the phase transition from the superconductive state to the normal phase. We find that $T_c$ is higher by a factor 1.5 -2 in comparison to the model containing no Polyakov loop. We also compute the specific heat $C_v$ near the second order phase transition and we show that the inclusion of the Polyakov loop does not change the value of the critical exponent.

  1. Tests of quantum chromodynamics in exclusive e sup + e sup minus and. gamma. gamma. processes

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1989-09-01

    This paper discusses the following topics: Factorization theorem for exclusive processes; Electromagnetic form factors of baryons; Suppression of final state interactions; The {gamma}{pi}{sub 0} Transition form factor; Exclusive charmonium decays; The {pi}-{rho} puzzle; Time-like compton processes; Multi-hadron production; Heavy Quark exclusive states and form factor zeros in QCD; Exclusive {gamma}{gamma} reactions; Higher twist effects; and Tauonium and threshold {tau}{sup +}{tau}{sup {minus}} production. 41 refs., 15 figs. (LSP)

  2. Computation of quark mass anomalous dimension at $O(1/N_{f}^{2})$ in quantum chromodynamics

    CERN Document Server

    Ciuchini, M; Gracey, J A; Manashov, A N

    2000-01-01

    We present the formalism to calculate d-dimensional critical exponents in QCD in the large N_f expansion where N_f is the number of quark flavours. It relies in part on demonstrating that at the d-dimensional fixed point of QCD the critical theory is equivalent to a non-abelian version of the Thirring model. We describe the techniques used to compute critical two and three loop Feynman diagrams and as an application determine the quark wave function, eta, and mass renormalization critical exponents at O(1/N_f^2) in d-dimensions. Their values when expressed in relation to four dimensional perturbation theory are in exact agreement with the known four loop MSbar results. Moreover, new coefficients in these renormalization group functions are determined to six loops and O(1/N_f^2). The computation of the exponents in the Schwinger Dyson approach is also provided and an expression for eta in arbitrary covariant gauge is given.

  3. A model of unified quantum chromodynamics and Yang-Mills gravity

    CERN Document Server

    Hsu, Jong-Ping

    2011-01-01

    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) \\times [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.

  4. Developments in lattice quantum chromodynamics for matter at high temperature and density

    Indian Academy of Sciences (India)

    Gert Aarts

    2015-05-01

    A brief overview of the QCD phase diagram at nonzero temperature and density is provided. It is explained why standard lattice QCD techniques are not immediately applicable for its determination, due to the sign problem. A selection of recent lattice approaches that attempt to evade the sign problem are then discussed and classified according to the underlying principle: constrained simulations (density of states, histograms), holomorphicity (complex Langevin, Lefschetz thimbles), partial summations (clusters, subsets, bags) and change in integration order (strong coupling, dual formulations).

  5. The SLUGGS survey: chromo-dynamical modelling of the lenticular galaxy NGC 1023

    CERN Document Server

    Cortesi, Arianna; Pota, Vincenzo; Foster, Caroline; Coccato, Lodovico; de Oliveira, Claudia Mendes; Forbes, Duncan A; Merrifield, Michael M; Bamford, Steven P; Romanowsky, Aaron J; Brodie, Jean P; Kartha, Sreeja S; Alabi, Adebusola B; Proctor, Robert N; Almeida, Andres

    2015-01-01

    Globular clusters (GCs) can be considered discrete, long-lived, dynamical tracers that retain crucial information about the assembly history of their parent galaxy. In this paper, we present a new catalogue of GC velocities and colours for the lenticular galaxy NGC 1023, we study their kinematics and spatial distribution, in comparison with the underlying stellar kinematics and surface brightness profile, and we test a new method for studying GC properties. Specifically, we decompose the galaxy light into its spheroid (assumed to represent the bulge + halo components) and disk components and use it to assign to each GC a probability of belonging to one of the two components. Then we model the galaxy kinematics, assuming a disk and spheroidal component, using planetary nebulae (PNe) and integrated stellar light. We use this kinematic model and the probability previously obtained from the photometry to recalculate for each GC its likelihood of being associated with the disk, the spheroid, or neither. We find th...

  6. High energy collisions of dense hadrons in quantum chromodynamics: LHC phenomenology and universality of parton distributions

    International Nuclear Information System (INIS)

    As the value of the longitudinal momentum carried by partons in a ultra-relativistic hadron becomes small, one observes a growth of their density. When the parton density becomes close to a value of order 1/αs, it does not grow any longer, it saturates. These high density effects seem to be well described by the Color Glass Condensate effective field theory. On the experimental side, the LHC provides the best tool ever for reaching the saturated phase of hadronic matter. For this reason saturation physics is a very active branch of QCD during these past and coming years since saturation theories and experimental data can be compared. I first deal with the phenomenology of the proton-lead collisions performed in winter 2013 at the LHC and whose data are about to be available. I compute the di-gluon production cross-section which provides the simplest observable for funding quantitative evidences of saturation in the kinematic range of the LHC. I also discuss the limit of the strongly correlated final state at large transverse momenta and by the way, generalize parton distribution to dense regime. The second main topic is the quantum evolution of the quark and gluon spectra in nucleus-nucleus collisions having in mind the proof of its universal character. This result is already known for gluons and here I detail the calculation carefully. For quarks universality has not been proved yet but I derive an intermediate leading order to next-to leading order recursion relation which is a crucial step for extracting the quantum evolution. Finally I briefly present an independent work in group theory. I detail a method I used for computing traces involving an arbitrary number of group generators, a situation often encountered in QCD calculations. (author)

  7. A survey of lattice results on finite temperature quantum chromodynamics

    Indian Academy of Sciences (India)

    E Laermann

    2003-04-01

    The talk summarizes some new results of lattice investigations of QCD at finite temperature. The topics discussed cover the flavor dependence of the critical temperature and the equation-of-state as well as hadronic correlation functions.

  8. The road towards the international linear collider: Higgs, top/quantum chromodynamics, loops

    Indian Academy of Sciences (India)

    S Heinemeyer

    2007-11-01

    The international linear +− collider (ILC) could go into operation in the second half of the upcoming decade. Experimental analyses and theory calculations for the physics at the ILC are currently performed. We review recent progress, as presented at the LCWS06 in Bangalore, India, in the fields of Higgs boson physics and top/QCD. Also the area of loop calculations, necessary to achieve the required theory precision, is included.

  9. Asymptotic freedom in the front-form Hamiltonian for quantum chromodynamics of gluons

    Science.gov (United States)

    Gómez-Rocha, María; Głazek, Stanisław D.

    2015-09-01

    Asymptotic freedom of gluons in pure-gauge QCD is obtained in the leading terms of their renormalized Hamiltonian in the Fock space, instead of considering virtual Green's functions or scattering amplitudes. Namely, we calculate the three-gluon interaction term in the effective front-form Hamiltonian for gluons in the Minkowski space-time using the renormalization group procedure for effective particles (RGPEP), with a new generator. The resulting three-gluon vertex is a function of the scale parameter, s , that has an interpretation of the size of effective gluons. The corresponding Hamiltonian running coupling constant, gλ, depending on the associated momentum scale λ =1 /s , is calculated in the series expansion in powers of g0=gλ 0 up to the terms of third order, assuming some small value for g0 at some large λ0. The result exhibits the same finite sensitivity to small-x regularization as the one obtained in an earlier RGPEP calculation, but the new calculation is simpler than the earlier one because of a simpler generator. This result establishes a degree of universality for pure-gauge QCD in the RGPEP.

  10. Asymptotic freedom in the front-form Hamiltonian for quantum chromodynamics of gluons

    CERN Document Server

    Gomez-Rocha, Maria

    2015-01-01

    Asymptotic freedom of gluons in QCD is obtained in the leading terms of their renormalized Hamiltonian in the Fock space, instead of considering virtual Green's functions or scattering amplitudes. Namely, we calculate the three-gluon interaction term in the front-form Hamiltonian for effective gluons in the Minkowski space-time using the renormalization group procedure for effective particles (RGPEP), with a new generator. The resulting three-gluon vertex is a function of the scale parameter, $s$, that has an interpretation of the size of effective gluons. The corresponding Hamiltonian running coupling constant, $g_\\lambda$, depending on the associated momentum scale $\\lambda = 1/s$, is calculated in the series expansion in powers of $g_0 = g_{\\lambda_0}$ up to the terms of third order, assuming some small value for $g_0$ at some large $\\lambda_0$. The result exhibits the same finite sensitivity to small-$x$ regularization as the one obtained in an earlier RGPEP calculation, but the new calculation is simpler...

  11. Theoretical studies of phenomenological models of nuclear chromodynamics: Progress report, January 1, 1988-December 31, 1988

    International Nuclear Information System (INIS)

    During the first year of our renewed research program significant progress has been made on the following research problems: in computing both elastic and inelastic pion-nucleon scattering phase shifts in the (1,1) and (3,3) channels within our pionic nontopological soliton model; in developing a new method for computing quantum soliton states and energies for all momenta in relativistic quantum field theory; and in applying the subsidiary condition theorem to soliton quantization in relativistic quantum field theory. These topics are discussed in this paper

  12. Commensurate scale relations: Precise tests of quantum chromodynamics without scale or scheme ambiguity

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Lu, H.J. [Maryland Univ., College Park, MD (United States). Dept. of Physics

    1994-10-01

    We derive commensurate scale relations which relate perturbatively calculable QCD observables to each other, including the annihilation ratio R{sub e+}e{sup {minus}}, the heavy quark potential, {tau} decay, and radiative corrections to structure function sum rules. For each such observable one can define an effective charge, such as {alpha}{sub R}({radical}s)/{pi} {equivalent_to} R {sub e+}e{sup {minus}}({radical}s)/(3{Sigma}e{sub q}{sup 2}){minus}1. The commensurate scale relation connecting the effective charges for observables A and B has the form {alpha}{sub A}(Q{sub A}) {alpha}{sub B}(Q{sub B})(1 + r {sub A/B}{sub {pi}}/{sup {alpha}B} + {hor_ellipsis}), where the coefficient r{sub A/B} is independent of the number of flavors {integral} contributing to coupling renormalization, as in BLM scale-fixing. The ratio of scales Q{sub A}/Q{sub B} is unique at leading order and guarantees that the observables A and B pass through new quark thresholds at the same physical scale. In higher orders a different renormalization scale Q{sup n*} is assigned for each order n in the perturbative series such that the coefficients of the series are identical to that of a invariant theory. The commensurate scale relations and scales satisfy the renormalization group transitivity rule which ensures that predictions in PQCD are independent of the choice of an intermediate renormalization scheme C. In particular, scale-fixed predictions can be made without reference to theoretically constructed singular renormalization schemes such as MS. QCD can thus be tested in a new and precise way by checking that the effective charges of observables track both in their relative normalization and in their commensurate scale dependence. The commensurate scale relations which relate the radiative corrections to the annihilation ratio R{sub e{sup +}e{sup {minus}}} to the radiative corrections for the Bjorken and Gross-Llewellyn Smith sum rules are particularly elegant and interesting.

  13. Root mean square radii of heavy flavoured mesons in a quantum chromodynamics potential model

    Indian Academy of Sciences (India)

    D K CHOUDHURY; TAPASHI DAS

    2016-10-01

    We report the results of root mean square (r.m.s.) radii of heavy flavoured mesons in a QCD model with the potential $V (r) = −(4\\alpha_{s}/3r) + br + c$. As the potential is not analytically solvable, we first obtain the results in the absence of confinement and Coulomb terms respectively. Confinement and Coulomb effects are then introduced successively in the approach using the Dalgarno’s method of perturbation. We explicitly consider the following two quantum mechanical aspects in the analysis: (a) The scale factor $c$ in the potential should not effect the wave function of the system even while applying the perturbation theory. (b) Choice of perturbative piece of the Hamiltonian (confinement or linear) should determine the effective radial separation between the quarks and antiquarks. The results are then compared with the available theoretical values of r.m.s. radii.

  14. 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.

  15. Realistic calculation of observables of the deep inelastic muon-proton scattering in perturbative quantum chromodynamics

    International Nuclear Information System (INIS)

    A model for deep inelastic lepton-hadron scattering is presented that includes non-perturbative effects as intrinsic transverse momentum, target, quark masses and hadronization, in QCD-perturbation theory in a way consistent with factorization. It allows realistic predictions for the Q2-evolution of structure functions as well as in combination with a semi-classical fragmentation model using a Monte-Carlo simulation for any measurable quantity in deep-inelastic scattering. The model is applied to various observables in muon-proton-reactions. The numerical results which are in good agreement with experimental data for a mean intrinsic transverse momentum of =0.7 GeV, differ from those of pure perturbation theory. (orig.)

  16. Experimental results on QCD [Quantum Chromodynamics] from e+e- annihilation

    International Nuclear Information System (INIS)

    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

  17. Experimental results on QCD (Quantum Chromodynamics) from e/sup +/e/sup -/ annihilation

    Energy Technology Data Exchange (ETDEWEB)

    de Boer, W.

    1987-09-01

    A review is given on QCD results from studying e/sup +/e/sup -/ annihilation with the PEP and PETRA storage rings with special emphasis on jet physics and the determination of the strong coupling constant ..cap alpha../sub s/. 92 refs., 28 figs., 3 tabs.

  18. Polyakov loop and the color-flavor locked phase of Quantum Chromodynamics

    OpenAIRE

    Ciminale, M.; Nardulli, G.; Ruggieri, M.; Gatto, R.

    2007-01-01

    We consider the Polyakov Nambu Jona Lasinio model with three massless quarks at high density and moderate temperature in the superconductive color flavor locking phase. We compute the critical temperature $T_c$ as a function of the baryonic chemical potential for the phase transition from the superconductive state to the normal phase. We find that $T_c$ is higher by a factor 1.5 -2 in comparison to the model containing no Polyakov loop. We also compute the specific heat $C_v$ near the second ...

  19. Low-energy effective models for two-flavor quantum chromodynamics and the universality hypothesis

    International Nuclear Information System (INIS)

    Our thesis is centered around the question of which order the chiral phase transition of two-flavor QCD is. First of all we outline several general aspects of phase transitions which are of central importance for the understanding of the RG approach towards them. Our focus lies on reviewing the universality hypothesis, a crucial ingredient when it comes to the construction of effective theories for order parameters, the credibility of which often heavily depends on universality arguments. We finish the chapter with an attempt to formulate the latter more precisely than usually done. The next chapter discusses the chiral phase transition from a general point of view. We supplement well-known facts with a detailed discussion of the so-called O(4) conjecture. Thereafter we introduce the nonperturbative method we use, the FRG method. Furthermore, we discuss the relation between effective models for QCD and the underlying fundamental theory making use of the FRG perspective. The next chapter is concerned with a mathematical subject indispensable for our approach towards the study of phase transitions, namely the systematic construction of polynomial invariants characterizing a given symmetry. With this thesis we point out its relevance in the context of high-energy physics. We present a simple, but novel, brute-force algorithm to effectively construct invariants of a given polynomial order. The next chapter is devoted to RG studies of several dimensionally reduced theories which are capable to either predict or to rule out the possible existence of a second-order phase transition. Of main interest for us is the linear sigma model, particularly in presence of the axial anomaly. It turns out that the fixed-point structure of the latter is rather complicated, requiring a deeper understanding of the underlying method and its preconditions. This leads us to a careful analysis of the fixed-point structure of several models, which is of great benefit for our review of the universality hypothesis and has several spin-off effects. For example, in the course of studying the influence of vector and axial-vector mesons we encounter a new universality class, which might be more relevant in other areas where chirality plays a role. Some important questions, however, cannot be addressed in the framework of dimensionally reduced theories where the explicit dependence of temperature has been eliminated. We are therefore pushed towards FRG studies where the temperature is kept as an explicit variable. We note that a great part of our work consisted in finding our own implementations of suitable algorithms to solve the encountered partial differential equations numerically. Then our main goal, the application to effective models for QCD, is discussed.

  20. A model of unified quantum chromodynamics and Yang-Mills gravity

    OpenAIRE

    Hsu, Jong-Ping

    2011-01-01

    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) \\times [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 t...

  1. Color transparency and the structure of the proton in quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Quantum Chromodynamics and nuclear physics at extreme energy density. Progress report, May 1992--April 1993

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, B.

    1993-05-15

    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.

  3. Unusual initial and final state effects in quantum chromodynamics: Progress report, July 15, 1987-March 1, 1988

    International Nuclear Information System (INIS)

    We have constructed fundamental tests which can be used to probe discrete symmetries, and their possible violations, in the required ''new physics'' beyond the standard model. For spin 0 decay into tau+tau- yielding an observable lepton pair l2l2 we have obtained analytically the full sequential decay correlation function I(E1, E2, cos psi12) = S + γ/sub CP/D in the Higgstechnipion rest frame. For fixed psi12, contour plots of this E1 energy-E2 energy correlation function have been made for M/sub H/ = 9 GeV and 70 GeV to show the difference between γ/sub CP/ = +-. We are continuing to investigate our proposal that partons be identified with nearly degenerate, coherent quark-gluon ''jet'' states in order to settle whether the associated ''jet based factorization'' is a natural property of QCD and whether it maintains the universality of mass singularities and the factorization of QCD processes into short-distance and long-distance parts. 4 figs

  4. A study on the determination of the scale parameter ΛMS of quantum chromodynamics at LEP I energies

    International Nuclear Information System (INIS)

    A method of measuring independently of jet rates the scale parameter Λsub(anti Manti S) for the determination of the running coupling constant αs of QCD is investigated. Using the LUND-program with exact matrix elements, the method is based on the energy dependence of observables like reduced thrust, jet masses and integrated asymmetry of energy-energy correlation (IAEEC). Only the IAEEC is able to reproduce the input scale parameter, Λsub(anti Manti S)=0.500 GeV, whereas the other variables yield smaller results than predicted. If the three jet cross section is, however, formulated with ERT-matrix elements, which are not included in the standard LUND code, it is possible to reproduce Λsub(anti Manti S) also from reduced thrust and jet masses. (orig.)

  5. Slope and curvature of Isgur–Wise function using variationally improved perturbation theory in a quantum chromodynamics inspired potential model

    Indian Academy of Sciences (India)

    Bhaskar Jyoti Hazarika; D K Choudhury

    2010-09-01

    We used variationally improved perturbation theory (VIPT) in calculating the slope and curvature of Isgur–Wise (I–W) function with the Cornell potential $− \\dfrac{4_{s}}{3r} br + c$ instead of the usual stationary state perturbation theory as done earlier. We used $−(4_{s} /3r)$, i.e. the Coulombic potential, as the parent and the linear one, i.e. $br +c$ as the perturbed potential in the theory and calculated the slope and curvature of Isgur–Wise function including three states in the summation involved in the first-order correction to wave function in the method.

  6. Reggeon, Pomeron and Glueball, Odderon-Hadron-Hadron Interaction at High Energies--From Regge Theory to Quantum Chromodynamics

    Institute of Scientific and Technical Information of China (English)

    XIONG Wen-Yuan; HU Zhao-Hui; WANG Xin-Wen; ZHOU Li-Juan; XIA Li-Xin; MA Wei-Xing

    2008-01-01

    Based on analysis of scattering matrix S, and its properties such as analyticity, unitarity, Lorentz invariance, and crossing symmetry relation, the Regge theory was proposed to describe hadron-hadron scattering at high energies before the advent of QCD, and correspondingly a Reggeon concept was born as a mediator of strongly interaction. This theory serves as a successful approach and has explained a great number of experimental data successfully, which proves that the Regge theory can be regarded as a basic theory of hadron interaction at high energies and its validity in many applications. However, as new experimental data come out, we have some difficulties in explaining the data. The new experimental total cross section violates the predictions of Regge theory, which shows that Regge formalism is limited in its applications to high energy data. To understand new experimental measurements, a new exchange theory was consequently born and its mediator is called Pomeron, which has vacuum quantum numbers. The new theory named as Pomeron exchange theory which reproduces the new experimental data of diffractive processes successfully. There are two exchange mediators: Reggeon and Pomeron. Reggeon exchange theory can only produce data at the relatively lower energy region, while Pomeron exchange theory fits the data only at higher-energy region, separately. In order to explain the data in the whole energy region, we propose a Reggeon-Pomeron model to describe high-energy hadron-hadron scattering and other diffractive processes. Although the Reggeon-Pomeron model is successful in describing high-energy hadron-hadron interaction in the whole energy region, it is a phenomenological model After the advent of QCD, people try to reveal the mystery of the phenomenological theory from QCD since hadron-hadron processes is a strong interaction, which is believed to be described by QCD. According to this point of view, we study the QCD nature of Reggeon and Pomeron. We claim that the Reggeon exchange is an exchange of multigluon, the color singlet gluon bound state. In particular, the Pomeron could be a Reggeized tensor glueba11 ξ(2230) with mass of 2.23 GeV, quantum numbers IG, JPC = 0+, 2++ and decay width of about 100 MeV. The glueball exchange theory reproduces data quite well. Accordingly, we believe that the Odderon, consisting of three Reggeized gluons, and predicted by QCD, should also contribute to hadron-hadron scattering and many other diffractive processes. We search for the Odderon by studying pp and pp elastic scatterings at high energies. Our investigations on the differential cross section da / dt of hadron-hadron scattering at various energies and comparisons with experimental data show that the Odderon plays an essential role in fitting to data. Therefore, we suggest that the measurements should be urgently done in order to confirm the existences of the Odderon and to test QCD.

  7. Quantum chromodynamics and nuclear physics at extreme energy density. Progress report, May 15, 1993--May 14, 1994

    International Nuclear Information System (INIS)

    This report briefly discusses the following topics: quark-gluon plasma and high-energy collisions; hadron structure and chiral dynamics; nonperturbative studies and nonabelian gauge theories; and studies in quantum field theory

  8. Review of the theory and phenomenology of lepton pair production. [Review Drell-Yan mechanism, parton distribution, gluon radiation, quantum chromodynamics, transverse momentum

    Energy Technology Data Exchange (ETDEWEB)

    Hwa, R. C.

    1978-05-01

    Recent experimental data and theoretical developments on the production of lepton pairs in hadron collisions are reviewed. With emphasis on the interplay between theory and experiment, the relevance of theoretical calculations to the data available at present energies is critically examined. The Drell--Yan mechanism is found to be phenomenologically dominant provided that the parton distribution functions contain effects of gluon radiation in a narrow cone. Explicit QCD perturbative calculations of the non-Drell--Yan type yield results that are apparently important at large transverse momenta, but are contradicated by subsequent data at 400 GeV and below. A consistent picture in the parton model is sketched. Further experiments to probe the basic mechanism are suggested. 83 references.

  9. Chiral phase transitions in quantum chromodynamics at finite temperature: Hard-thermal-loop resummed Dyson–Schwinger equation in the real time formalism

    Indian Academy of Sciences (India)

    Hisao Nakkagawa; Hiroshi Yokota; Koji Yoshida; Yuko Fueki

    2003-05-01

    Chiral phase transition in thermal QCD is studied by using the Dyson–Schwinger (DS) equation in the real time hard thermal loop approximation. Our results on the critical temperature and the critical coupling are significantly different from those in the preceding analyses in the ladder DS equation, showing the importance of properly taking into account the essential thermal effects, namely the Landau damping and the unstable nature of thermal quasiparticles.

  10. Inclusive results at 900, at I.S.R., favourable to a diquark under-structure of the proton, and estimations of quantum chromodynamics

    International Nuclear Information System (INIS)

    Inclusive measurements of protons and antiprotons, at ninety degrees, generated in proton-antiproton or proton-proton interactions, give different information. After an improvement in the particles' identification as a result of the association of silicagel detectors and the time of flight, the following results were achieved: the global test of the CR and CP invariances in strong proton-antiproton, and the need of a proton scalar diquark under-structure to explain the anomalous level of protons, either in agreement to other similar experiments or very different. The name of covalon or coquark for this bound state is proposed. In ultra-relativistic heavy ions interactions, the covalons' suppression would be a new and strong identification sign for quarks and gluons plasma

  11. (Experimental and theoretical basic research in high energy physics)

    Energy Technology Data Exchange (ETDEWEB)

    1991-04-01

    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. (LSP)

  12. Expectations for ultra-high energy interactions

    International Nuclear Information System (INIS)

    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

  13. Theory and phenomenology of strong and weak interaction high energy physics

    International Nuclear Information System (INIS)

    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

  14. Heavy-quark QCD vacuum polarisation function. Analytical results at four loops

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, B.A.; Kotikov, A.V. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2006-07-15

    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.)

  15. Research in high energy physics

    International Nuclear Information System (INIS)

    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 conformal field theory. (LSP)

  16. Spin-isospin mixing without spontaneous symmetry breakdown

    Science.gov (United States)

    Mukhrejee, A.; Roy, Probir

    1983-06-01

    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.

  17. Spectroscopy of mesonic states containing light quarks (u,d,s) or gluons

    International Nuclear Information System (INIS)

    In this thesis the description of meson spectra in the framework of quantum chromodynamics is reviewed. Particularly considered are quarkonium states, glueballs, hermaphrodites, and four-quark states. (HSI)

  18. The relativity of Colour

    CERN Document Server

    Stack, Paul D

    2015-01-01

    By attaching three anticommuting Lorentz scalar (colour) property coordinates to space-time, with an appropriate extended metric, we unify gravity with chromodynamics: gauge transformations then just correspond to coordinate transformations in the enlarged spacetime-property space.

  19. From gauge-string duality to strong interactions: a Pedestrian's Guide

    CERN Document Server

    Gubser, Steven S

    2009-01-01

    We survey recent progress in understanding the relation of string theory to quantum chromodynamics, focusing on holographic models of gauge theories similar to QCD and applications to heavy-ion collisions.

  20. Theory and phenomenology of strong and weak interaction high energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Carruthers, P.; Thews, R.L.

    1990-08-29

    This paper deals with research being conducted at the University of Arizona in the theory of strong and weak interactions. Topics in Quantum chromodynamics, quantum electrodynamics, symmetry principle, hadronic structure of the photon and other are discussed. (LSP)

  1. QCD Multipole Expansion and Hadronic Transitions in Heavy Quarkonium Systems

    Institute of Scientific and Technical Information of China (English)

    KUANG Yu-ping

    2006-01-01

    We review the developments of the multipole expansion approach in quantum chromodynamics and its applications to hadronic transitions and some radiative decays of heavy quarkonia.Theoretical predictions are compared with updated experimental results.

  2. EMC effect: asymptotic freedom with nuclear targets

    International Nuclear Information System (INIS)

    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

  3. Cross sections for five jet production above the W+W- threshold in e+e- annihilation

    International Nuclear Information System (INIS)

    We describe the calculation of five jet production from the W+W- intermediate state in e+e- annihilation in lowest order quantum chromodynamics. Some results for integrated Cross-sections are presented. (author)

  4. An empirical approach to the theory of particle and nuclear phenomena: Review and some new ideas

    Indian Academy of Sciences (India)

    Raja Ramanna; Sudhir R Jain

    2001-08-01

    Experimental data on masses and lifetimes of unstable particles falls into a pattern, a brief review of some interesting consequences is presented here. From the experience in semiclassical methods and recent advances in quantum chromodynamics, it is proposed that an appropriate generalization of the Gutzwiller trace formula for field theories may lead to a systematic semiclassical chromodynamics theory. The theory can be developed to get appropriate dynamics leading to an explanation of pattern discovered in the empirical data.

  5. 7th CERN - Latin-American School of High-Energy Physics

    CERN Document Server

    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.

  6. Proceedings of the 2013 CERN - Latin-American School of High-Energy Physics (CLASHEP 2013), Arequipa, Peru, 6-19 Mar 2013

    OpenAIRE

    Mulders, M; Perez, G

    2016-01-01

    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 introdu...

  7. Finite temperature corrections to a NLO Nambu-Jona-Lasinio model

    CERN Document Server

    Frasca, Marco

    2016-01-01

    We derive the next-to-leading order correction to the Nambu-Jona-Lasinio model starting from quantum chromodynamics. So, we are able to fix the constants of the Nambu-Jona-Lasinio model from quantum chromodynamics and analyze the behavior of strong interactions at low energies. The technique is to expand in powers of currents the generating functional. We apply it to a simple Yukawa model with self-interaction showing how this has a Nambu-Jona-Lasinio model and its higher order corrections as a low-energy limit. The same is shown to happen for quantum chromodynamics in the chiral limit with two quarks. We prove that a consistent thermodynamic behaviour is obtained as expected for the given parameters.

  8. Electric dipole moment of the neutron in a gauge theory

    International Nuclear Information System (INIS)

    The problem of calculation of the electric dipole moment (EDM) of the neutron in a gauge theory is discussed. The consideration is carried out in the Kobayashi and Maskawa model of complex couplings, models with spontaneous CP violation and in the framework of quantum chromodynamics. The EDM of the neutron induced by the theta term of quantum chromodynamics is of order of (10-15-10-16) | theta | e cm. The mechanism of the spontaneous CP violation predicts the value of EDM coinciding practically with experimental data. The mechanism of CP violation due to complex couplings predicts the value of EDM of approximately 10-32 e cm

  9. From enemies to friends chiral symmetry on the lattice

    CERN Document Server

    Hernández, Pilar; Lellouch, L P; Hernandez, Pilar; Jansen, Karl; Lellouch, Laurent

    2002-01-01

    The physics of strong interactions is invariant under the exchange of left-handed and right-handed quarks, at least in the massless limit. This invariance is reflected in the chiral symmetry of quantum chromodynamics. Surprisingly, it has become clear only recently how to implement this important symmetry in lattice formulations of quantum field theories. We will discuss realizations of exact lattice chiral symmetry and give an example of the computation of a physical observable in quantum chromodynamics where chiral symmetry is important. This calculation is performed by relying on finite size scaling methods as predicted by chiral perturbation theory.

  10. Parallel supercomputers for lattice gauge theory.

    Science.gov (United States)

    Brown, F R; Christ, N H

    1988-03-18

    During the past 10 years, particle physicists have increasingly employed numerical simulation to answer fundamental theoretical questions about the properties of quarks and gluons. The enormous computer resources required by quantum chromodynamic calculations have inspired the design and construction of very powerful, highly parallel, dedicated computers optimized for this work. This article gives a brief description of the numerical structure and current status of these large-scale lattice gauge theory calculations, with emphasis on the computational demands they make. The architecture, present state, and potential of these special-purpose supercomputers is described. It is argued that a numerical solution of low energy quantum chromodynamics may well be achieved by these machines.

  11. Classical Hamiltonian Dynamics and Lie Group Algebras

    CERN Document Server

    Aycock, B; Silverberg, J L; Widom, A

    2008-01-01

    The classical Hamilton equations of motion yield a structure sufficiently general to handle an almost arbitrary set of ordinary differential equations. Employing elementary algebraic methods, it is possible within the Hamiltonian structure to describe many physical systems exhibiting Lie group symmetries. Elementary examples include magnetic moment precession and the mechanical orbits of color charged particles in classical non-abelian chromodynamics.

  12. CEBAF/SURA [Continuous Electron Beam Accelerator Facility]/[Southeastern Universities Research Association] 1987 summer workshop

    International Nuclear Information System (INIS)

    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 14N

  13. From surface roughening to QCD string theory

    Energy Technology Data Exchange (ETDEWEB)

    Keisuke Jimmy Juge et al.

    2001-05-23

    Surface critical phenomena and the related onset of Goldstone modes represent fundamental properties of the confining flux in Quantum Chromodynamics. New ideas on surface roughening and their implications for lattice studies of quark confinement and string formation are presented. Problems with a simple string description of the large Wilson surface are discussed.

  14. The Origin of Mass

    CERN Document Server

    Raya, Alfredo

    2009-01-01

    Dynamical chiral symmetry breaking and confinement are two crucial features of Quantum Chromodynamics responsible for the nature of the hadron spectrum. These phenomena, presumably coincidental, can account for 98% of the mass of our visible universe. In this set of lectures, I shall present an introductory review of them in the light of the Schwinger-Dyson equations.

  15. Lattice QCD and the CKM matrix

    CERN Document Server

    De Grand, T

    2001-01-01

    These lectures (given at TASI 2000) provide an introduction to lattice methods for nonperturbative studies of Quantum Chromodynamics. Lecture 1 (Ch. 2) is a very vanilla introduction to lattice QCD. Lecture 2 (Ch. 3) describes examples of recent lattice calculations relevant to fixing the parameters of the CKM matrix.

  16. 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...

  17. Anisotropic Flow and flow fluctuations at the Large Hadron Collider

    NARCIS (Netherlands)

    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 t

  18. Investigation of Dilaton-Gluon Coupling Potential in Charmonium Family

    Institute of Scientific and Technical Information of China (English)

    PING Rong-Gang; CHEN Hong; PING Rong-Xiang

    2006-01-01

    The behaviour of dilaton-gluon coupling (DGC) potential is investigated by studying charmonium spectra,annihilation rates and E1 transition rates systematically.We find that in the non-relativistic quantum chromodynamics approximation,the charmonium properties can be described by the DGC potential.

  19. Higgs production at next-to-next-to-leading order

    Indian Academy of Sciences (India)

    V Ravindran; J Smith; W L Van Neerven

    2004-03-01

    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.

  20. QCD with dynamical fermions on the connection machine

    International Nuclear Information System (INIS)

    Our collaboration has implemented Quantum Chromo-Dynamics (QCD) on the massively-parallel Connection Machine, in *Lisp. The code uses dynamical Wilson fermions and the Hybrid Monte Carlo Algorithm (HMCA) to update the lattice. We describe our program, and give performance measurements for it. With no tuning or optimization, the code runs at approximately 100 Mflops on a 64K CM-2. (orig.)

  1. Proceedings of the 2010 European School of High-energy Physics, Raseborg, Finland, 20 Jun - 3 Jul 2010

    OpenAIRE

    C. Grojean; Spiropulu, M.

    2012-01-01

    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, heavy ion physics, physics beyond the Standard Model, neutrino physics, and cosmology.

  2. Proceedings of the 2012 European School of High-Energy Physics (ESHEP 2012), La Pommeraye, Anjou, France, 06-19 Jun 2012

    OpenAIRE

    C. Grojean; Mulders, M

    2015-01-01

    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.

  3. Theory explaining it all doesn't quite

    CERN Document Server

    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)

  4. Path integral approach to two-dimensional QCD in the light-front frame

    Energy Technology Data Exchange (ETDEWEB)

    Gaete, P. (Instituto de Fisica, Universidade Federal do Rio de Janeiro, C.P. 68528, BR-21945, Rio de Janeiro (Brazil)); Gamboa, J. (Fachbereich 7 Physik, Universitaet Siegen, Siegen, D-57068 (Germany)); Schmidt, I. (Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile))

    1994-05-15

    Two-dimensional quantum chromodynamics in the light-front frame is studied following Hamiltonian methods. The theory is quantized using the path integral formalism and an effective theory similar to the Nambu--Jona-Lasinio model is obtained. Confinement in two dimensions is derived by analyzing directly the constraints in the path integral.

  5. Unitary quantum gases: from cold atoms to quark-gluon plasmas

    NARCIS (Netherlands)

    van Heugten, J. J. R. M.

    2013-01-01

    We investigate the many-body properties of two distinct degenerate systems with strong interactions, namely that of a quark-gluon plasma and of an atomic Bose gas. In the first part of this thesis, the temperature dependence of the thermodynamic potential of quantum chromodynamics is studied. In par

  6. Research in elementary particle physics

    Science.gov (United States)

    Kirsch, L. E.; Schnitzer, H. J.

    Research in theoretical and experimental properties of elementary particles is described. This includes measurements made at the multiparticle spectrometer facility at Brookhaven, studies of baryonium production, inclusive hyperon production, and E(0) production. Theoretical work included extended field theories, subconstituent models, finite temperature quatum chromodynamics, grad unified theories, and calculational techniques in gauge theories.

  7. Potts Flux Tube Model at Nonzero Chemical Potential

    CERN Document Server

    Condella, J; Condella, Jac; Tar, Carleton De

    2000-01-01

    We model the deconfinement phase transition in quantum chromodynamics at nonzero baryon number density and large quark mass by extending the flux tube model (three-state, three-dimensional Potts model) to nonzero chemical potential. In a direct numerical simulation we confirm mean-field-theory predictions that the deconfinement transition does not occur in a baryon-rich environment.

  8. Introduction to the physics of the quark-gluon plasma and how it might be produced in hadronic collisions

    International Nuclear Information System (INIS)

    Strong interactions and the structure of Quantum Chromodynamics are most easily studied in systems involving one, two or an infinite number of particles. High energy density hadronic matter offers many possibilities for studying infinite particle systems. Topics which may be addressed are the confinement-deconfinement phase transition, chiral symmetry breaking and the applicability of cascade and hydrodynamic models to nucleus-nucleus collisions

  9. Theoretical aspects of electroweak and other interactions in medium energy nuclear physics

    International Nuclear Information System (INIS)

    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

  10. Scenarios for physics at LEP

    International Nuclear Information System (INIS)

    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.)

  11. Lemon : An MPI parallel I/O library for data encapsulation using LIME

    NARCIS (Netherlands)

    Deuzeman, Albert; Reker, Siebren; Urbach, Carsten

    2012-01-01

    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 Encapsulati

  12. The structure of the proton: The CT14 QCD global analysis

    Science.gov (United States)

    Dulat, S.; Hou, T.-J.; Gao, J.; Guzzi, M.; Huston, J.; Nadolsky, P.; Pumplin, J.; Schmidt, C.; Stump, D.; Yuan, C.-P.

    2016-07-01

    A brief description of the CT14 global analysis of quantum chromodynamics at next-to-next-to leading order (NNLO) from the CTEQ-TEAgroup is given. Predictions for standard candle processes at the LHC are illustrated together with the main features of the CT14 parton distribution functions

  13. Parity violation workshop: CEBAF [Continuous Electron Beam Accelerator Facility

    International Nuclear Information System (INIS)

    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

  14. QCD in the infrared with exact angular integrations

    NARCIS (Netherlands)

    Atkinson, D; Bloch, J.C R

    1998-01-01

    In a previous paper we have shown that in quantum chromodynamics the gluon propagator vanishes in the infrared limit, while the ghost propagator is more singular than a simple pole. These results were obtained after angular averaging, but here we go beyond this approximation and perform an exact cal

  15. Running coupling in nonperturbative QCD : Bare vertices and y-max approximation

    NARCIS (Netherlands)

    Atkinson, D; Bloch, JCR

    1998-01-01

    A recent claim that in quantum chromodynamics tin the Landau gauge) the gluon propagator Vanishes in the infrared limit, while the ghost propagator is more singular than a simple pole, is investigated analytically and numerically. This picture is shown to be supported even at the level in which the

  16. Quarks and gluons in low-p/sub T/ physics

    International Nuclear Information System (INIS)

    Review and comment are given on some of the existing approaches to low-p/sub T/ particle production based on ideas of quantum chromodynamics. The relationships between the various theories are emphasized and, the points of overlap between them are noted. Constraints upon the models coming from deep inelastic and e+e- annihilation data are discussed

  17. Analytic stochastic regularization and gauge theories

    International Nuclear Information System (INIS)

    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)

  18. 2009 European School of High-energy Physics

    OpenAIRE

    Grojean, C.; Spiropulu, M.

    2010-01-01

    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 quantum field theory, quantum chromodynamics, physics beyond the Standard Model, flavour physics, effective field theory, cosmology, as well as statistical data analysis.

  19. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1988-07-01

    Highlights of the VIIIth International Workshop on Photon-Photon Collisions are reviewed. New experimental and theoretical results were reported in virtually every area of ..gamma gamma.. physics, particularly in exotic resonance production and tests of quantum chromodynamics where asymptotic freedom and factorization theorems provide predictions for both inclusive and exclusive ..gamma gamma.. reactions at high momentum transfer. 73 refs., 12 figs.

  20. Brookhaven: Spin result underlined

    International Nuclear Information System (INIS)

    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

  1. Pulse pile-up recovery for the front-end electronics of the PANDA Electromagnetic Calorimeter

    NARCIS (Netherlands)

    Tambave, G.; Guliyev, E.; Kavatsyuk, M.; Schreuder, F.; Lohner, 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

  2. Pulse pile-up recovery for the front-end electronics of the PANDA Electromagnetic Calorimeter

    NARCIS (Netherlands)

    Tambave, G.; Kavatsyuk, M.; Guliyev, E.; Schreuder, F.; Moeini, H.; Lohner, 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 annihi

  3. Strong interactions in air showers

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, Dennis D. [Arnold Sommerfeld Center, Ludwig-Maximilians-Universität, Theresienstraße, München (Germany); Institut für Theoretische Physik, Goethe-Universität, Max-von-Laue-Straße, Frankfurt am Main (Germany)

    2015-03-02

    We study the role new gauge interactions in extensions of the standard model play in air showers initiated by ultrahigh-energy cosmic rays. Hadron-hadron events remain dominated by quantum chromodynamics, while projectiles and/or targets from beyond the standard model permit us to see qualitative differences arising due to the new interactions.

  4. Heavy quarks

    International Nuclear Information System (INIS)

    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.)

  5. Theoretical high energy physics: Progress report, May 1, 1987-April 30, 1988

    International Nuclear Information System (INIS)

    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

  6. Theoretical high energy physics

    International Nuclear Information System (INIS)

    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

  7. The SIRI stochastic model with creation and annihilation operators

    OpenAIRE

    Stollenwerk, Nico; Aguiar, Maira

    2008-01-01

    We generalize the well known formulation of the susceptibles, infected, susceptibles (SIS) spatial epidemics with creation and annihilation operators to the reinfection model including recovered which can be reinfected, the SIRI model, using ladder operators constructed from the Gell-Mann matrices known in quantum chromodynamics.

  8. High energy physics at Tufts University. Progress report, July 16, 1985-July 15, 1986

    International Nuclear Information System (INIS)

    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

  9. On the Confinement of Quarks without Applying the Bag Pressure

    OpenAIRE

    Sharifi, Mohammad

    2014-01-01

    We explain a fatal error in quantum chromodynamics. By applying a correction to the dynamics of quarks, we can confine quarks in hadrons. We will show why quarks do not obey the Pauli exclusion principle and why we cannot observe free quarks. In addition, we obtain correct hadron sizes.

  10. Research program in elementary particle theory: Progress report, January 1, 1987-December 1987

    International Nuclear Information System (INIS)

    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

  11. Monte Carlo simulations in theoretical physic; Simulations Monte Carlo en physique theorique

    Energy Technology Data Exchange (ETDEWEB)

    Billoire, A.

    1991-12-31

    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.

  12. 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.

  13. Nuclear physics studies with medium energy probes. Progress report and renewal proposal

    International Nuclear Information System (INIS)

    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

  14. WWNPQFT-2010 - Slides of the presentations

    International Nuclear Information System (INIS)

    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

  15. The structure of the proton: The CT14 QCD global analysis

    Directory of Open Access Journals (Sweden)

    Dulat S.

    2016-01-01

    Full Text Available A brief description of the CT14 global analysis of quantum chromodynamics at next-to-next-to leading order (NNLO from the CTEQ-TEAgroup is given. Predictions for standard candle processes at the LHC are illustrated together with the main features of the CT14 parton distribution functions

  16. Early steps towards quarks and their interactions using neutrino beams in CERN bubble chamber experiments

    Science.gov (United States)

    Perkins, Don H.

    2016-06-01

    Results from neutrino experiments at CERN in the1970's, using bubble chamber detectors filled with heavy liquids, gave early evidence for the existence of quarks and gluons as real dynamical objects. In detail, the measured moments of the non-singlet structure functions provided crucial support for the validity of the present theory of the strong inter-quark interactions, quantum chromodynamics.

  17. Chiral condensates and QCD vacuum in two dimensions

    CERN Document Server

    Christiansen, H R

    1997-01-01

    We analyze the chiral symmetries of flavored quantum chromodynamics in two dimensions and show the existence of 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.

  18. Topological contributions to fermionic correlators and nonperturbative aspects of QCD in two dimensions

    CERN Document Server

    Christiansen, H

    1999-01-01

    We analyze the formation of fermionic condensates in two dimensional quantum chromodynamics for matter in the fundamental representation of the gauge group. We show that a topological regular instanton background is crucial in order to obtain nontrivial correlators. We discuss both massless and massive cases.

  19. The NLO QCD Corrections to $B_c$ Meson Production in $Z^0$ Decays

    CERN Document Server

    Qiao, Cong-Feng; Zhu, Rui-Lin

    2011-01-01

    The decay width of $Z^0$ to $B_c$ meson is evaluated at the next-to-leading order(NLO) accuracy in strong interaction. Numerical calculation shows that the NLO correction to this process is remarkable. The quantum chromodynamics(QCD)renormalization scale dependence of the results is obviously depressed, and hence the uncertainties lying in the leading order calculation are reduced.

  20. Proceedings of the 8 Warsaw symposium on elementary particle physics, Kazimierz, Poland, May 26 - June 1, 1985

    International Nuclear Information System (INIS)

    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.)

  1. Phenomenology of cosmic phase transitions

    International Nuclear Information System (INIS)

    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

  2. Concept for an Electron Ion Collider (EIC) detector built around the BaBar solenoid

    CERN Document Server

    Adare, A; 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; Bandara, N S; Bannier, B; Barish, K N; Bathe, S; Baublis, V; Bazilevsky, A; Beaumier, M; Beckman, S; Belmont, R; Berdnikov, A; Berdnikov, Y; Black, D; Bok, J; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Campbell, S; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Chujo, T; Citron, Z; Csanád, M; Csörgő, T; Datta, A; Daugherity, M S; David, G; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Ding, L; Dion, A; Do, J H; Drees, A; Drees, K A; Durham, J M; Durum, A; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fokin, S L; Frantz, J E; Franz, A; Frawley, A D; Gal, C; Gallus, P; Garg, P; Ge, H; Giordano, F; Glenn, A; Goto, Y; Grau, N; Greene, S V; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guragain, H; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Han, S Y; Hanks, J; Hasegawa, S; He, X; Hemmick, T K; Hill, J C; Hollis, R S; Homma, K; Hong, B; Hoshino, T; Huang, J; Huang, S; Ikeda, Y; Imai, K; Imazu, Y; Inaba, M; Iordanova, A; Isenhower, D; Ivanishchev, D; Jacak, B V; Jeon, S J; Jezghani, M; Jia, J; Jiang, X; Johnson, B M; Joo, E; Joo, K S; Jouan, D; Jumper, D S; Kang, J H; Kang, J S; Kawall, D; Kazantsev, A V; Key, J A; Khachatryan, V; Khanzadeev, A; Kihara, K; Kim, C; Kim, D H; Kim, D J; Kim, E -J; Kim, H -J; Kim, M; Kim, Y K; Kistenev, E; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Kofarago, M; Koster, J; Kotov, D; Kurita, K; Kurosawa, M; Kwon, Y; Lacey, R; Lajoie, J G; Lebedev, A; Lee, K B; Lee, S H; Leitch, M J; Leitgab, M; Lim, S H; Liu, M X; Lynch, D; Makdisi, Y I; Makek, M; Manion, A; Manko, V I; Mannel, E; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mignerey, A C; Miller, A; Milov, A; Mishra, D K; Mitchell, J T; Miyasaka, S; Mizuno, S; Montuenga, P; Moon, T; Morrison, D P; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagle, J L; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakano, K; Nattrass, C; Netrakanti, P K; Nihashi, M; Niida, T; Nouicer, R; Novitzky, N; Nyanin, A S; O'Brien, E; Ogilvie, C A; Koop, J D Orjuela; Osborn, J; Oskarsson, A; Ozaki, H; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, S; Pate, S F; Patel, L; Patel, M; Peng, J -C; Perepelitsa, D; Perera, G D N; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Purschke, M L; Rak, J; Ravinovich, I; Read, K F; Reynolds, R; Riabov, V; Riabov, Y; Riveli, N; Roach, D; Rolnick, S D; Rosati, M; Rowan, Z; Rubin, J; Saito, N; Sakaguchi, T; Sako, H; Samsonov, V; Sarsour, M; Sato, S; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Singh, B K; Singh, C P; Slunečka, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Stepanov, M; Stoll, S P; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Takahara, A; Taketani, A; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Timilsina, A; Todoroki, T; Tomášek, M; Torii, H; Towell, M; Towell, R; Towell, R S; Tserruya, I; van Hecke, H W; Vargyas, M; Velkovska, J; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, Y; Watanabe, Y S; Wei, F; Whitaker, S; Wolin, S; Woody, C L; Wysocki, M; Xia, B; Xue, L; Yalcin, S; Yamaguchi, Y L; Yanovich, A; Yoon, I; Younus, I; Yushmanov, I E; Zajc, W A; Zelenski, A

    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.

  3. When is a particle

    International Nuclear Information System (INIS)

    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

  4. Jet and photon physics in pp collisions at the LHC

    CERN Document Server

    Ciulli, Vitaliano

    2016-01-01

    Jets and photons production in proton-proton collisions at the Large Hadron Collider at CERN are key processes to test predictions of Quantum Chromodynamics and constraint the parton distribution functions of the proton. In this paper the most recent measurements from the LHC Collaborations are reviewed.

  5. Eta'-meson as pseudoscalar gluonium

    International Nuclear Information System (INIS)

    It is proved the sum rules of quantum chromodynamics for a current constructed of the gluon field operators are saturated by the eta'-meson. The meson mass is estimated and its residue in the gluon current. There is a considerable difference between the eta'-meson as gluon and the classical quark states such as the delta-meson. (orig.)

  6. Lectures on the foundations of QCD

    OpenAIRE

    Smilga, A. V.

    1999-01-01

    The paper is withdrawn by the author. This was an embryon of the book which has now been published with World Scientific under the title "Lectures on Quantum Chromodynamics". See http://www.wspc.com.sg/books/physics/4443.html, where the beginning of the book will soon be available in the pdf format.

  7. Comparison of Inclusive Charm and Beauty Cross Sections in Deep-inelastic Scattering at HERA with Theoretical Predictions

    CERN Document Server

    Thompson, P D

    2007-01-01

    The measurements of inclusive charm and beauty cross sections in deep-inelastic scattering $ep$ collisions at HERA are compared with the predictions of perturbative quantum chromodynamics from the CTEQ and MRST fitting groups, employing a range of theoretical schemes. The differences in the theoretical predictions are discussed and the theoretical uncertainties investigated.

  8. The Structure of the Nucleon, Three Decades of Investigation (1967-2004)

    Science.gov (United States)

    Bodek, Arie

    2005-02-01

    A personal historical account of three decades of experiments that led to a detailed understanding of the structure of the nucleon and the theory of Quantum Chromodynamics. (Panofsky Prize 2004 Talk, Presented at NuInt04, Mar. 2004, Laboratori Nazionali del Gran Sasso - INFN - Assergi, Italy [ http://nuint04.lngs.infn.it/])

  9. Proceedings of the school for young high energy physicists, Rutherford Appleton Laboratory, September 8-20 1986

    International Nuclear Information System (INIS)

    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.)

  10. OBE approximation of NN scattering in bag-model QCD

    Science.gov (United States)

    Bakker, B. L. G.; Maslow, J. N.; Weber, H. J.

    1981-09-01

    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 ≈350 MeV.

  11. 2010 European School of High-energy Physics

    CERN Document Server

    Spiropulu, M

    2012-01-01

    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, heavy ion physics, physics beyond the Standard Model, neutrino physics, and cosmology.

  12. Multi-baryons in QCD(2)

    Energy Technology Data Exchange (ETDEWEB)

    Frishman, Y. (Weizmann Inst. of Science, Rehovoth (Israel). Dept. of Physics); Zakrzewski, W.J. (Durham Univ. (UK). Dept. of Mathematical Siences)

    1989-12-18

    We find multi-baryon states in two-dimensional quantum chromodynamics. We show that to bind two baryons the model must involve at least seven flavours. All calculations are performed in the strong coupling limit and the semiclassical approximation is employed in the derivation of the results. We briefly comment on the properties of the derived states. (orig.).

  13. Meson Electro-/Photo-Production from QCD

    Science.gov (United States)

    Briceño, Raúl A.

    2016-10-01

    I present the calculation of the π ^+γ ^star → π ^+π ^0 transition amplitude from quantum chromodynamics performed by the Hadron Spectrum Collaboration. The amplitude is determined for a range of values of the photon virtuality and the final state energy. One observes a clear dynamical enhancement due to the presence of the ρ resonance. By fitting the transition amplitude and analytically continuing it onto the ρ -pole, the ρ → π γ ^star form factor is obtained. This exploratory calculation, performed using lattice quantum chromodynamics, constitutes the very first determination of an electroweak decay of a hadronic resonance directly from the fundamental theory of quarks and gluons. In this talk, I highlight some of the necessary steps that made this calculation possible, placing emphasis on recently developed formalism. Finally, I discuss the status and outlook of the field for the study of Nγ ^star → N^star → Nπ transitions.

  14. Quarks and numerical simulation

    International Nuclear Information System (INIS)

    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 1017 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

  15. 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......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 effective model that the chiral symmetry is broken again by the spin-polarized condensate on increasing the quark number density, while chiral symmetry restoration occurs, in which the chiral condensate disappears at a certain density....

  16. Nonperturbative light-front QCD

    CERN Document Server

    Wilson, K G; Harindranath, A; Zhang, W M; Perry, R J; Glazek, S D

    1994-01-01

    In this work the determination of low-energy bound states in Quantum Chromodynamics is recast so that it is linked to a weak-coupling problem. This allows one to approach the solution with the same techniques which solve Quantum Electrodynamics: namely, a combination of weak-coupling diagrams and many-body quantum mechanics. The key to eliminating necessarily nonperturbative effects is the use of a bare Hamiltonian in which quarks and gluons have nonzero constituent masses rather than the zero masses of the current picture. The use of constituent masses cuts off the growth of the running coupling constant and makes it possible that the running coupling never leaves the perturbative domain. For stabilization purposes an artificial potential is added to the Hamiltonian, but with a coefficient that vanishes at the physical value of the coupling constant. The weak-coupling approach potentially reconciles the simplicity of the Constituent Quark Model with the complexities of Quantum Chromodynamics. The penalty for...

  17. ''Asymptotic freedom'' in quantum mechanics

    International Nuclear Information System (INIS)

    Sum rules in quantum mechanics true for nonsingular potentials are considered. The physical content of sum rules is reduced to the fact that at small distances the interaction energy is small as compared with kinetic energy and the interaction may be considered as perturbation. In this sense there exists a direct analogy with quantum chromodynamics sum rules, previously discussed in detail. The common character of the situation found for the first time in the case of quantum chromodynamics: if the interaction grows fast with the distance increase one may obtain sum rules which on the one hand use Born approximation of interaction, on the other - they are saturated by one-two low levels

  18. Nonperturbative light-front Hamiltonian methods

    Science.gov (United States)

    Hiller, J. R.

    2016-09-01

    We examine the current state-of-the-art in nonperturbative calculations done with Hamiltonians constructed in light-front quantization of various field theories. The language of light-front quantization is introduced, and important (numerical) techniques, such as Pauli-Villars regularization, discrete light-cone quantization, basis light-front quantization, the light-front coupled-cluster method, the renormalization group procedure for effective particles, sector-dependent renormalization, and the Lanczos diagonalization method, are surveyed. Specific applications are discussed for quenched scalar Yukawa theory, ϕ4 theory, ordinary Yukawa theory, supersymmetric Yang-Mills theory, quantum electrodynamics, and quantum chromodynamics. The content should serve as an introduction to these methods for anyone interested in doing such calculations and as a rallying point for those who wish to solve quantum chromodynamics in terms of wave functions rather than random samplings of Euclidean field configurations.

  19. Nonperturbative light-front Hamiltonian methods

    CERN Document Server

    Hiller, J R

    2016-01-01

    We examine the current state-of-the-art in nonperturbative calculations done with Hamiltonians constructed in light-front quantization of various field theories. The language of light-front quantization is introduced, and important (numerical) techniques, such as Pauli--Villars regularization, discrete light-cone quantization, basis light-front quantization, the light-front coupled-cluster method, the renormalization group procedure for effective particles, sector-dependent renormalization, and the Lanczos diagonalization method, are surveyed. Specific applications are discussed for quenched scalar Yukawa theory, $\\phi^4$ theory, ordinary Yukawa theory, supersymmetric Yang--Mills theory, quantum electrodynamics, and quantum chromodynamics. The content should serve as an introduction to these methods for anyone interested in doing such calculations and as a rallying point for those who wish to solve quantum chromodynamics in terms of wave functions rather than random samplings of Euclidean field configurations...

  20. Nondissipative currents link graphene and heavy ion physics

    CERN Document Server

    Mizher, Ana Julia; Villavicencio, Cristian

    2013-01-01

    Monolayer graphite films, or graphene, have quasiparticle excitations that can be effectively described by (2+1)-dimensional quantum electrodynamics. Such a theory resembles more to quantum chromodynamics in some aspects, in particular, allowing for a non-trivial topological term in the gauge sector of the corresponding Lagrangian, the Chern-Simons term. In analogy to the chiral magnetic effect, proposed for quantum chromodynamics, we show that the presence of such topological gauge configurations associated to an external -in plane -magnetic field in a planar quantum elecrodynamical system, generates an electrical current along the magnetic field direction. This result is unexpected from the point of view of Maxwell equations and is uniquely due to the interaction of the gauge sector with the fermions.

  1. Towards an explanation of transverse single-spin asymmetries in proton-proton collisions: the role of fragmentation in collinear factorization

    CERN Document Server

    Kanazawa, K; Metz, A; Pitonyak, D

    2014-01-01

    We study the transverse single-spin asymmetry for single-hadron production in proton-proton collisions within the framework of collinear twist-3 factorization in Quantum Chromodynamics. By taking into account the contribution due to parton fragmentation we obtain a very good description of all high transverse-momentum data for neutral and charged pion production from the Relativistic Heavy Ion Collider. Our study may provide the crucial step towards a final solution to the longstanding problem of what causes transverse single-spin asymmetries in hadronic collisions within Quantum Chromodynamics. We show for the first time that, in a conceptually satisfactory framework, it is possible to simultaneously describe spin/azimuthal asymmetries in proton-proton collisions, semi-inclusive deep-inelastic scattering, and electron-positron annihilation.

  2. Meson electro-/photo-production from QCD

    CERN Document Server

    Briceño, Raúl A

    2016-01-01

    I present the calculation of the $\\pi^+\\gamma^\\star\\to\\pi^+\\pi^0$ transition amplitude from quantum chromodynamics performed by the Hadron Spectrum Collaboration. The amplitude is determined for a range of values of the photon virtuality and the final state energy. One observes a clear dynamical enhancement due to the presence of the $\\rho$ resonance. By fitting the transition amplitude and analytically continuing it onto the $\\rho$-pole, the $\\rho\\to\\pi\\gamma^\\star$ form factor is obtained. This exploratory calculation, performed using lattice quantum chromodynamics, constitutes the very first determination of an electroweak decay of a hadronic resonance directly from the fundamental theory of quarks and gluons. In this talk, I highlight some of the necessary steps that made this calculation possible, placing emphasis on recently developed formalism. Finally, I discuss the status and outlook of the field for the study of $N\\gamma^\\star\\to N^\\star\\to N\\pi$ transitions.

  3. Overview of recent results from the STAR experiment

    OpenAIRE

    Mustafa, Mustafa

    2015-01-01

    The Solenoidal Tracker at RHIC (STAR) experiment utilizes its excellent mid-rapidity tracking and particle identification capabilities to study the emergent properties of Quantum Chromodynamics (QCD). The STAR heavy-ion program at vanishingly small baryon density is aimed to address questions about the quantitative properties of the strongly-interacting Quark Gluon Plasma (QGP) matter created in high energy collisions ($\\eta/s$, $\\hat{q}$, chirality, transport parameters, heavy quark diffusio...

  4. Inclusive jet cross section at D0

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, M. [Delhi Univ. (India). Dept. of Physics and Astrophysics

    1996-09-01

    Preliminary measurement of the central ({vert_bar}{eta}{vert_bar} {<=} 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 {ital pb}{sup -1}) and 1994-1995 (90 {ital pb}{sup -1}) data samples are presented. Comparisons to Next-to-Leading Order (NLO) Quantum Chromodynamics (QCD) calculations are made.

  5. Bilocal bosonization of QCD and electroweak properties of light pseudoscalar mesons

    International Nuclear Information System (INIS)

    Quantum chromodynamic based analysis of the low energy electroweak properties of light pseudo-scalars is studied using an approximate bilocal bosonization technique. Particular attention is given to the problem of maintaining electroweak gauge invariance, and a bilocal Wilson-line technique is introduced to address this problem. The decay constants FK and Fπ and the π± charge radius are discussed in detail. 29 refs., 9 figs

  6. Isgur–Wise function in a quantum chromodynamicsinspired potential model with confinement as parent in the variationally improved perturbation theory

    Indian Academy of Sciences (India)

    Bhaskar Jyoti Hazarika; D K Choudhury

    2012-04-01

    We have recently reported the calculation of slope and curvature of Isgur–Wise function based on variationally improved perturbation theory (VIPT) in a quantum chromodynamics (QCD)-inspired potential model. In that work, Coulombic potential was taken as the parent while the linear one as the perturbation. In this work, we choose the linear one as the parent with Coulombic one as the perturbation and see the consequences.

  7. Vacuum quark condensate, chiral Lagrangian, and Bose-Einstein statistics

    International Nuclear Information System (INIS)

    In a series of articles it was recently claimed that the quantum chromodynamic (QCD) condensates are not the properties of the vacuum but of the hadrons and are confined inside them. We point out that this claim is incompatible with the chiral Lagrangian and Bose-Einstein statistics of the Goldstone bosons (pions) in chiral limit and conclude that the quark condensate must be the property of the QCD vacuum.

  8. 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.)

  9. Baryonium and non-exotic hadron trajectories from a color dependent potential

    International Nuclear Information System (INIS)

    A natural explanation is presented for the apparent increase in Regge slope with number of quarks in a bound state. The framework used is that of a non-relativistic harmonic oscillator potential with a color dependence suggested by quantum chromodynamics. The ratios of modes of orbital excitations in baryonium, baryon and meson states which are in good agreement with experiment are derived, and the modes of excitation within the baryonium states discussed

  10. 1997 European School of high-energy physics. Proceedings

    International Nuclear Information System (INIS)

    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.)

  11. Recherche d'un boson de Higgs chargé avec le détecteur ATLAS : de la théorie à l'expérience

    OpenAIRE

    Weydert, Carole

    2011-01-01

    This thesis is intended as a bridge between the two highly specialised domains of phenomenology and experimental particle physics. The first part describes in detail a higher order cross section calculation and implementation into a Monte Carlo event generator. We present the calculation of the next-to-leading order (NLO) quantum chromodynamic corrections for charged Higgs boson production in association with a top quark at the LHC, using the Catani-Seymour dipole subtraction method. Building...

  12. Improved Nucleon Properties in the Extended Quark Sigma Model

    CERN Document Server

    Abu-Shady, M

    2013-01-01

    The quark sigma model describes the quarks interacting via exchange the pions and sigma meson fields. A new version of mesonic potential is suggested in the frame of some aspects of the quantum chromodynamics (QCD). The field equations have been solved in the mean-field approximation for the hedgehog baryon state. The obtained results are compared with previous works and other models. We conclude that the suggested mesonic potential successfully calculates nucleon properties.

  13. QCD with dynamical fermions on the Connection Machine

    International Nuclear Information System (INIS)

    The authors implemented Quantum Chromo-Dynamics (QCD) on the massively parallel Connection Machine in *Lisp. The code used dynamical Wilson fermions and the Hybrid Monte Carlo Algorithm (HMCA) to update the lattice. This paper describes the authors' program and give performance measurements for it. With no tuning or optimization, the code runs at approximately 500 to 1000 MFLOPS on a 64K Connection Machine, model CM-s, depending on the VP ratio

  14. chi_{c1} and chi_{c2} decay angular distributions at the Fermilab Tevatron

    CERN Document Server

    Kniehl, Bernd A; Palisoc, C P

    2003-01-01

    We consider the hadroproduction of chi_{c1} and chi_{c2} mesons and their subsequent radiative decays to J/psi mesons and photons in the factorization formalism of nonrelativistic quantum chromodynamics, and study the decay angular distributions, by means of helicity density matrices, in view of their sensitivity to color-octet processes. We present numerical results appropriate for the Fermilab Tevatron.

  15. Correct approach to consideration of experimental resolution in parametric analysis of scaling violation in deep inelastic lepton-nucleon interaction

    International Nuclear Information System (INIS)

    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 χ2-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.)

  16. Exploring and testing the Standard Model and beyond

    International Nuclear Information System (INIS)

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The goal of this project was to extend and develop the predictions of the Standard Model of particle physics in several different directions. This includes various aspects of the strong nuclear interactions in quantum chromodynamics (QCD), electroweak interactions and the origin of baryon asymmetry in the universe, as well as gravitational physics

  17. The many faces of strange matter: compact stars, cosmic rays, and dark matter

    CERN Document Server

    Xu, Renxin

    2015-01-01

    The state of cold bulk matter at around nuclear density depends on the fundamental strong interaction between quarks at low-energy scale, so-called non-perturbative quantum chromo-dynamics. Such kind of matter is conjectured to be condensed matter of 3-flavour (u, d and s) quark clusters in this note, being manifested in the form of compact stars, cosmic rays, and even dark matter.

  18. Proceedings, 2011 European School of High-Energy Physics (ESHEP 2011): Cheile Gradistei, Romania, September 7-20, 2011

    OpenAIRE

    Grojean; C; Van, Mulders, P.; M

    2015-01-01

    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 quantum field theory and the Standard Model, quantum chromodynamics, flavour physics, neutrino physics, physics beyond the Standard Model, cosmology, heavy ion physics, statistical data analysis, as well as an account for the physics results with the data accumulated during the f...

  19. Perspectives in nuclear physics

    Science.gov (United States)

    Thomas, A. W.

    2011-09-01

    We discuss some of the many important questions in modern subatomic physics that have been addressed over the past two decades at Mainz. These achievements range from precision studies of nucleon form factors, to nucleon spectroscopy, novel probes of nucleon structure such as virtual Compton scattering and fundamental tests of quantum chromodynamics. In the future one may expect to see this effort expanded to precision tests of physics beyond the Standard Model.

  20. Proceedings of the 1st Asia-Europe-Pacific School of High-Energy Physics (AEPSHEP 12), Fukuoka, Japan, 14 - 27 Oct 2012

    OpenAIRE

    K. Kawagoe; Mulders, M

    2014-01-01

    The Asia-Europe-Pacific 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, flavour physics and CP-violation, physics beyond the Standard Model, neutrino physics, particle cosmology, heavy-ion physics, as well as a presentation of recent results from the Large Hadron Collider (LHC), practical statistics...

  1. 5th CERN - Latin-American School of High-Energy Physics

    OpenAIRE

    C. Grojean; 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...

  2. To flow or not to flow : a study of elliptic flow and nonflow in proton-proton collisions in ALICE

    OpenAIRE

    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 temperatures and densities: the Quark Gluon plasma. The ALICE experiment at the Large Hadron Collider near Geneva was build to study this QGP by looking at collisions of the most heavy stable ions: le...

  3. On the calculation of soft phase space integral

    OpenAIRE

    Zhu, Hua

    2014-01-01

    The recent discovery of the Higgs boson at the LHC attracts much attention to the precise calculation of its production cross section in quantum chromodynamics. In this work, we discuss the calculation of soft triple-emission phase space integral, which is an essential ingredient in the recently calculated soft-virtual corrections to Higgs boson production at next-to-next-to-next-to-leading order. The main techniques used this calculation are method of differential equation for Feynman integr...

  4. Hamiltonian Light-Front Field Theory: Recent Progress and Tantalizing Prospects

    OpenAIRE

    Vary, James P.

    2011-01-01

    Fundamental theories, such as Quantum Electrodynamics (QED) and Quantum Chromodynamics (QCD) promise great predictive power addressing phenomena over vast scales from the microscopic to cosmic scales. However, new non-perturbative tools are required for physics to span from one scale to the next. I outline recent theoretical and computational progress to build these bridges and provide illustrative results for Hamiltonian Light Front Field Theory. One key area is our development of basis func...

  5. Properties of scalar gluonium

    Energy Technology Data Exchange (ETDEWEB)

    Salomone, A.; Schechter, J.; Tudron, T.

    1981-03-01

    We examine the properties of a scalar glueball in a simple effective-Lagrangian model which satisfies both the axial-vector and trace anomaly equations of quantum chromodynamics. The scalar-glueball decay pattern can be predicted if its mass is specified and may present some unusual features. In this approach a characteristic mass scale is directly related to the vacuum energy density which automatically comes out to be of a nonperturbative type.

  6. Unresolved theoretical problems

    International Nuclear Information System (INIS)

    A summary is given of nuclear physics ideas which form the perspective within which the spin excitations in nuclei should be considered. Past work on the nuclear shell model, nuclear collective motion, cluster degrees of freedom and isobaric analogic resonances is reviewed. Indications of the future directions physicists should be taking are discussed. The importance of joining quantum chromodynamics with study of atomic nuclei, and in particular the GT resonance, is highlighted

  7. Proceedings of the 2009 CERN-Latin-American School of High-Energy Physics, Recinto Quirama, Colombia, 15 - 28 March 2009

    OpenAIRE

    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...

  8. Nuclear enhanced power corrections to DIS structure functions

    OpenAIRE

    Guo, Xiaofeng; Qiu, Jianwei; Zhu, Wei

    2001-01-01

    We calculate nuclear enhanced power corrections to structure functions measured in deeply inelastic lepton-nucleus scattering in Quantum Chromodynamics (QCD). We find that the nuclear medium enhanced power corrections at order of $O(\\alpha_s/Q^2)$ enhance the longitudinal structure function $F_L$, and suppress the transverse structure function $F_1$. We demonstrate that strong nuclear effects in $\\sigma_A/\\sigma_D$ and $R_A/R_D$, recently observed by HERMES Collaboration, can be explained in ...

  9. Spectral Properties of the Wilson Dirac Operator and random matrix theory

    OpenAIRE

    Kieburg, Mario; Verbaarschot, Jacobus J. M.; Zafeiropoulos, Savvas

    2013-01-01

    Random Matrix Theory has been successfully applied to lattice Quantum Chromodynamics. In particular, a great deal of progress has been made on the understanding, numerically as well as analytically, of the spectral properties of the Wilson Dirac operator. In this paper, we study the infra-red spectrum of the Wilson Dirac operator via Random Matrix Theory including the three leading order $a^2$ correction terms that appear in the corresponding chiral Lagrangian. A derivation of the joint proba...

  10. New twists to QCD at large-N

    International Nuclear Information System (INIS)

    The recently discovered reduced models of Quantum Chromodynamics in the limit of a large number (N) of colors are discussed, in particular the version that employs appropriate Z(N) twists. Some preliminary numerical data are presented, together with some new analytic results (saddle-points). This may be of some help for understanding the mechanism of confinement, which presumably is the same for all N. Also, the reduced chiral model in two dimensions is discussed

  11. Twenty-five Years of Lattice Gauge Theory: Consequences of the QCD Lagrangian

    CERN Document Server

    Kronfeld, Andreas S

    2010-01-01

    When the Lake Louise Winter Institute started twenty-five years ago, many properties of quantum chromodynamics (QCD) were believed to be true, but had not been demonstrated to be true. This talk surveys a variety of results that have been established with lattice gauge theory, directly from the QCD Lagrangian, shedding light on the origin of (your) mass and its interplay with dynamical symmetry breaking, as well as some further intriguing features of the natural world.

  12. Gluonia

    International Nuclear Information System (INIS)

    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

  13. Impacts of the Soft-Gluon Exchanges on B→ππ Decays

    Institute of Scientific and Technical Information of China (English)

    吴向尧; 李作宏; 崔建营; 黄涛

    2002-01-01

    We have investigated the role of soft-gluon exchanges in B →ππ, using the light-cone sum rules in quantum chromodynamics. The calculations are carried out not only for the tree operators but also for the penguin operators. We conclude that soft-gluon exchanges contribute to the decay amplitudes, noticeably on some decay channels, and thus cannot be neglected.

  14. Accelerating dark-matter axion searches with quantum measurement technology

    OpenAIRE

    Zheng, Huaixiu; Silveri, Matti; Brierley, R. T.; Girvin, S. M.; Lehnert, K. W.

    2016-01-01

    The axion particle, a consequence of an elegant hypothesis that resolves the strong-CP problem of quantum chromodynamics, is a plausible origin for cosmological dark matter. In searches for axionic dark matter that detect the conversion of axions to microwave photons, the quantum noise associated with microwave vacuum fluctuations will soon limit the rate at which parameter space is searched. Here we show that this noise can be partially overcome either by squeezing the quantum vacuum using r...

  15. The physics of the theta-angle for composite extensions of the standard model

    DEFF Research Database (Denmark)

    di Vecchia, Paolo; Sannino, Francesco

    2014-01-01

    We analyse the θ-angle physics associated to extensions of the standard model of particle interactions featuring new strongly coupled sectors. We start by providing a pedagogical review of the θ-angle physics for Quantum Chromodynamics (QCD) including also the axion properties. We then move to an...... representations. Our analysis is of immediate use for different models of composite Higgs dynamics, composite dark matter and inflation....

  16. 1993 European school of high-energy physics. Proceedings

    International Nuclear Information System (INIS)

    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 quantum field theory, quantum chromodynamics, CP violation, radiative corrections, cosmology, particle detectors and e+e- accelerators, as well as reports on results from HERA and LEP and accounts of particle physics research at CERN and in Poland and Russia. (orig.)

  17. Possible interpretation on the origin of four-fermion interaction

    CERN Document Server

    Kohyama, Hiroaki

    2016-01-01

    We present a possible interpretation on the origin of the four-fermion interaction used in effective field theories. Inspired by the sharp momentum peak seen in Bose-Einstein condensate state, we incorporate the special gluon condensate effect into the gluon propagator. We then find that, if one considers hypothetic situation with the condensed gluon, the four-fermion contact interaction can arise from the first principle theory of quantum chromodynamics.

  18. Aspects of Hadron Physics

    OpenAIRE

    Roberts, C. D.; Bhagwat, M. S.; Wright, S. V.; Holl, A

    2008-01-01

    Detailed investigations of the structure of hadrons are essential for understanding how matter is constructed from the quarks and gluons of Quantum chromodynamics (QCD), and amongst the questions posed to modern hadron physics, three stand out. What is the rigorous, quantitative mechanism responsible for confinement? What is the connection between confinement and dynamical chiral symmetry breaking? And are these phenomena together sufficient to explain the origin of more than 98% of the mass ...

  19. 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.

  20. Lattice gauge theory for QCD

    Energy Technology Data Exchange (ETDEWEB)

    DeGrand, T. [Univ. of Colorado, Boulder, CO (United States). Dept. of Physics

    1997-06-01

    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 {alpha}{sub s} (M{sub z}), and B-{anti B} mixing. 67 refs., 36 figs.

  1. Centrality dependence of direct photon production in (square root)S(NN) = 200 GeV Au + Au collisions.

    Science.gov (United States)

    Adler, S S; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Amirikas, R; Aphecetche, L; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, R; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bazilevsky, A; Belikov, S; Berdnikov, Y; Bhagavatula, S; Boissevain, J G; Borel, H; Borenstein, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Camard, X; Chai, J-S; Chand, P; Chang, W C; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J; Choudhury, R K; Chujo, T; Cianciolo, V; Cobigo, Y; Cole, B A; Constantin, P; d'Enterria, D; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Devismes, A; Dietzsch, O; Drapier, O; Drees, A; du Rietz, R; Durum, A; Dutta, D; Efremenko, Y V; El Chenawi, K; Enokizono, A; En'yo, H; Esumi, S; Ewell, L; Fields, D E; Fleuret, F; Fokin, S L; Fox, B D; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Gogiberidze, G; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Perdekamp, M Grosse; Guryn, W; Gustafsson, H-A; Hachiya, T; Haggerty, J S; Hamagaki, H; Hansen, A G; Hartouni, E P; Harvey, M; Hayano, R; Hayashi, N; He, X; Heffner, M; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Holzmann, W; Homma, K; Hong, B; Hoover, A; Ichihara, T; Ikonnikov, V V; Imai, K; Isenhower, D; Ishihara, M; Issah, M; Isupov, A; Jacak, B V; Jang, W Y; Jeong, Y; Jia, J; Jinnouchi, O; Johnson, B M; Johnson, S C; Joo, K S; Jouan, D; Kametani, S; Kamihara, N; Kang, J H; Kapoor, S S; Katou, K; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, D W; Kim, E; Kim, G-B; Kim, H J; Kistenev, E; Kiyomichi, A; Kiyoyama, K; Klein-Boesing, C; Kobayashi, H; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kopytine, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kuberg, C H; Kurita, K; Kuroki, Y; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Ladygin, V; Lajoie, J G; Lebedev, A; Leckey, S; Lee, D M; Lee, S; Leitch, M J; Li, X H; Lim, H; Litvinenko, A; Liu, M X; Liu, Y; Maguire, C F; Makdisi, Y I; Malakhov, A; Manko, V I; Mao, Y; Martinez, G; Marx, M D; Masui, H; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Messer, F; Miake, Y; Milan, J; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagle, J L; Nakamura, T; Nandi, B K; Nara, M; Newby, J; Nilsson, P; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, K; Ono, M; Onuchin, V; Oskarsson, A; Otterlund, I; Oyama, K; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Parmar, A; Pate, S F; Peitzmann, T; Peng, J-C; Peresedov, V; Pinkenburg, C; Pisani, R P; Plasil, F; Purschke, M L; Purwar, A K; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosnet, P; Ryu, S S; Sadler, M E; Saito, N; Sakaguchi, T; Sakai, M; Sakai, S; Samsonov, V; Sanfratello, L; Santo, R; Sato, H D; Sato, S; Sawada, S; Schutz, Y; Semenov, V; Seto, R; Shaw, M R; Shea, T K; Shibata, T-A; Shigaki, K; Shiina, T; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Sullivan, J P; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarján, P; Tepe, J D; Thomas, T L; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tuli, S K; Tydesjö, H; Tyurin, N; van Hecke, H W; Velkovska, J; Velkovsky, M; Veszprémi, V; Villatte, L; Vinogradov, A A; Volkov, M A; Vznuzdaev, E; Wang, X R; Watanabe, Y; White, S N; Wohn, F K; Woody, C L; Xie, W; Yang, Y; Yanovich, A; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zhou, S J; Zolin, L

    2005-06-17

    The first measurement of direct photons in Au + Au collisions at (square root)S(NN) = 200 GeV is presented. The direct photon signal is extracted as a function of the Au + Au collision centrality and compared to next-to-leading order perturbative quantum chromodynamics calculations. The direct photon yield is shown to scale with the number of nucleon-nucleon collisions for all centralities. PMID:16090462

  2. Centrality Dependence of Direct Photon Production in √(SNN)=200 GeV Au+Au Collisions

    International Nuclear Information System (INIS)

    The first measurement of direct photons in Au+Au collisions at √(sNN)=200 GeV is presented. The direct photon signal is extracted as a function of the Au+Au collision centrality and compared to next-to-leading order perturbative quantum chromodynamics calculations. The direct photon yield is shown to scale with the number of nucleon-nucleon collisions for all centralities

  3. Constraints imposed by CP conservation in the presence of pseudoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Peccei, R.D.; Quinn, H.R.

    1977-09-15

    We elaborate on an earlier discussion of CP conservation of strong interactions which includes the effect of pseudoparticles. We discuss what happens in theories of the quantum-chromodynamics type when we include weak and electromagnetic interactions. We find that strong CP conservation remains a natural symmetry if the full Lagrangian possesses a chiral U(1) invariance. We illustrate our results by considering in detail a recent model of (weak) CP nonconservation.

  4. Hadron Physics from Lattice QCD

    CERN Document Server

    Bietenholz, Wolfgang

    2016-01-01

    We sketch the basic ideas of the lattice regularization in Quantum Field Theory, the corresponding Monte Carlo simulations, and applications to Quantum Chromodynamics (QCD). This approach enables the numerical measurement of observables at the non-perturbative level. We comment on selected results, with a focus on hadron masses and the link to Chiral Perturbation Theory. At last we address two outstanding issues: topological freezing and the sign problem.

  5. Fluctuations and correlations introduction and overview

    CERN Document Server

    Kittel, E W

    2005-01-01

    Higher-order correlations have been observed as particle-density fluctuations. Approximate scaling with improving resolution provides evidence for a self-similar correlation effect. Quantum- Chromodynamics branching is a good candidate for a dynamical explanation of these correlations in e **+e**- collisions at CERN/LEP and, as expected, also of those in pp collisions at future CERN/LHC energies. However, also other sources such as identical-particle Bose-Einstein interference effects contribute.

  6. Highlights from LHC experiments and future perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Campana, P. [INFN - Laboratori Nazionali di Frascati, 00044 Frascati (Italy)

    2016-01-22

    The experiments at LHC are collecting a large amount of data in a kinematic of the (x, Q{sup 2}) variables never accessed before. Boosted by LHC analyses, Quantum Chromodynamics (QCD) is experiencing an impressive progress in the last few years, and even brighter perspectives can be foreseen for the future data taking. A subset of the most recent results from the LHC experiments in the area of QCD (both perturbative and soft) are reviewed.

  7. Theoretical studies in weak, electromagnetic and strong interactions. Attachments

    International Nuclear Information System (INIS)

    The project covered a wide area of current research in theoretical high-energy physics. This included Standard Model (SM) as well as physics beyond the Standard Model. Specific topics included supersymmetry (SUSY), perturbative quantum chromodynamics (QCD), a new weak interaction for the third family (called topflavor), neutrino masses and mixings, topcolor model, Pade approximation, and its application to perturbative QCD and other physical processes

  8. The Next-to-Leading Order Corrections to Top Quark Decays to Heavy Quarkonia

    CERN Document Server

    Sun, Peng; Qiao, Cong-Feng

    2010-01-01

    The decay widths of top quark to S-wave $b\\bar{c}$ and $b\\bar{b}$ bound states are evaluated at the next-to-leading(NLO) accuracy in strong interaction. Numerical calculation shows that the NLO corrections to these processes are remarkable. The quantum chromodynamics(QCD) renormalization scale dependence of the results are obviously depressed, and hence the uncertainties lying in the leading order calculation are reduced.

  9. Jet modification in 200 AGeV Au-Au collisions

    OpenAIRE

    Renk, Thorsten

    2008-01-01

    The computation of hard processes in hadronic collisions is a major success of perturbative Quantum Chromodynamics. The environment of heavy-ion collisions offers the opportunity to embed such hard processes into a soft medium which is created simultaneously and study the medium-induced modifications. On the level of single high transverse momentum hadrons, a reduction in yield, the so-called quenching is observed. However, on the level of jets, the energy-momentum flux carried by hadrons is ...

  10. Lattice gauge theory for QCD

    International Nuclear Information System (INIS)

    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 αs (Mz), and B-anti B mixing. 67 refs., 36 figs

  11. Scheme variations of the QCD coupling and hadronic $\\tau$ decays

    OpenAIRE

    Boito, Diogo; Jamin, Matthias; Miravitllas, Ramon

    2016-01-01

    The Quantum Chromodynamics (QCD) coupling, $\\alpha_s$, is not a physical observable of the theory since it depends on conventions related to the renormalization procedure. We introduce a definition of the QCD coupling, denoted by $\\widehat\\alpha_s$, whose running is explicitly renormalization scheme invariant. The scheme dependence of the new coupling $\\widehat\\alpha_s$ is parameterized by a single parameter $C$, related to transformations of the QCD scale $\\Lambda$. It is demonstrated that a...

  12. Regge behaviour of distribution functions and evolution of gluon distribution function in next-to-leading order at low-x

    Indian Academy of Sciences (India)

    U Jamil; J K Sarma

    2008-09-01

    Evolution of gluon distribution function from Dokshitzer–Gribov–Lipatov–Altarelli–Parisi (DGLAP) evolution equation in next-to-leading order (NLO) at low- is presented assuming the Regge behaviour of quark and gluon at this limit. We compare our results of gluon distribution function with MRST2004, GRV98LO and GRV98NLO parametrizations and show the compatibility of Regge behaviour of quark and gluon distribution functions with perturbative quantum chromodynamics (PQCD) at low-.

  13. Staggered domain wall fermions

    CERN Document Server

    Hoelbling, Christian

    2016-01-01

    We construct domain wall fermions with a staggered kernel and investigate their spectral and chiral properties numerically in the Schwinger model. In some relevant cases we see an improvement of chirality by more than an order of magnitude as compared to usual domain wall fermions. Moreover, we present first results for four-dimensional quantum chromodynamics, where we also observe significant reductions of chiral symmetry violations for staggered domain wall fermions.

  14. Convergences

    International Nuclear Information System (INIS)

    These are scattered remarks concerning what is happening to (not in) elementary particle physics. New developments are unfolding with unprecedented speed, so that one does not even attempt to give a comprehensive review at this time. Mostly charm is discussed, both its phenomenology and its impact on belief in quarks, chromodynamics, and unified theories. Beneath the newsworthy experimental discoveries of the last two years lies a quieter and more profound theoretical development: the emergence of a theory of particle physics

  15. 3. Theoretical Physics Division

    International Nuclear Information System (INIS)

    For the period September 1980 - Aug 1981, the studies in theoretical physics divisions have been compiled under the following headings: in nuclear physics, nuclear structure, nuclear reactions and intermediate energies; in particle physics, NN and NantiN interactions, dual topological unitarization, quark model and quantum chromodynamics, classical and quantum field theories, non linear integrable equations and topological preons and Grand unified theories. A list of publications, lectures and meetings is included

  16. Nuclear Forces and High-Performance Computing: The Perfect Match

    Energy Technology Data Exchange (ETDEWEB)

    Luu, T; Walker-Loud, A

    2009-06-12

    High-performance computing is now enabling the calculation of certain nuclear interaction parameters directly from Quantum Chromodynamics, the quantum field theory that governs the behavior of quarks and gluons and is ultimately responsible for the nuclear strong force. We briefly describe the state of the field and describe how progress in this field will impact the greater nuclear physics community. We give estimates of computational requirements needed to obtain certain milestones and describe the scientific and computational challenges of this field.

  17. Effective Field Theory for Lattice Nuclei

    OpenAIRE

    Barnea, N.; Contessi, L.; Gazit, D.; Pederiva, F.; van Kolck, U.

    2013-01-01

    We show how nuclear effective field theory (EFT) and ab initio nuclear-structure methods can turn input from lattice quantum chromodynamics (LQCD) into predictions for the properties of nuclei. We argue that pionless EFT is the appropriate theory to describe the light nuclei obtained in recent LQCD simulations carried out at pion masses much heavier than the physical pion mass. We solve the EFT using the effective-interaction hyperspherical harmonics and auxiliary-field diffusion Monte Carlo ...

  18. Quantifying truncation errors in effective field theory

    OpenAIRE

    Furnstahl, R. J.; Klco, N.; D. R. Phillips; Wesolowski, S.

    2015-01-01

    Bayesian procedures designed to quantify truncation errors in perturbative calculations of quantum chromodynamics observables are adapted to expansions in effective field theory (EFT). In the Bayesian approach, such truncation errors are derived from degree-of-belief (DOB) intervals for EFT predictions. Computation of these intervals requires specification of prior probability distributions ("priors") for the expansion coefficients. By encoding expectations about the naturalness of these coef...

  19. Exploring and testing the Standard Model and beyond

    Energy Technology Data Exchange (ETDEWEB)

    West, G.; Cooper, F.; Ginsparg, P.; Habib, S.; Gupta, R.; Mottola, E.; Nieto, M.; Mattis, M.

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The goal of this project was to extend and develop the predictions of the Standard Model of particle physics in several different directions. This includes various aspects of the strong nuclear interactions in quantum chromodynamics (QCD), electroweak interactions and the origin of baryon asymmetry in the universe, as well as gravitational physics.

  20. 1994 European school of high-energy physics. Proceedings

    International Nuclear Information System (INIS)

    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, physics beyond the Standard Model, Quantum Chromodynamics and CP violation, as well as reports on the search for gravitational waves, stellar death and accounts of particle physics at CERN and JINR. Two local subjects are also treated: Pompeii and Mount Vesuvius. (orig.)

  1. Obe approximation of NN scattering in bag-model QCD

    International Nuclear Information System (INIS)

    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.)

  2. Strong Gravity Approach to QCD and General Relativity

    OpenAIRE

    Akinto, O. F.; Tahir, Farida

    2016-01-01

    A systematic study of the Weyl-type / Yang-Mills-type action possessing local conformal invariance and quadratic curvature is undertaken. The dynamical breaking of this conformal invariance / scale invariance induces general relativity (GR) as an effective long distance limit of the theory. We prove that the corresponding field equations of the theory have the linearly rising potential, which naturally possesses asymptotic freedom and color confinement properties of quantum chromodynamics (QC...

  3. Axion Research at CAPP/IBS

    Science.gov (United States)

    Youn, Sungwoo

    2016-07-01

    The axion, a hypothetical fundamental particle, was postulated as an attractive solution to the CP problem in quantum chromodynamics and believed to be an ideal candidate for the cold dark matter. The Center for Axion and Precision Physics Research of the Institute for Basic Science has launched a state of the art experiment to search for the hypothesised new particle using microwave resonant cavities. I will discuss R&D efforts at our center and plans for the experiment.

  4. Effective quantum field theories

    International Nuclear Information System (INIS)

    Certain dimensional parameters play a crucial role in the understanding of weak and strong interactions based on SU(2) x U(1) and SU(3) symmetry group theories and of grand unified theories (GUT's) based on SU(5). These parameters are the confinement scale of quantum chromodynamics and the breaking scales of SU(2) x U(1) and SU(5). The concepts of effective quantum field theories and renormalisability are discussed with reference to the economics and ethics of research. (U.K.)

  5. Recent results from STAR experiment in Au+Au collisions at $\\sqrt{s_{NN}}$ = 9.2 GeV

    OpenAIRE

    Das, Debasish; Collaboration, for the STAR

    2009-01-01

    Theoretical models suggest that the Quantum Chromo-Dynamics (QCD) phase diagram has a critical point demarcating the order of transition between the two phases: the hadron gas, in which the quarks are confined and the Quark-Gluon Plasma (QGP). The central goal of the experiments with relativistic heavy-ion collisions is to create and study such form of matter called the QGP and understand the QCD phase diagram. The STAR (Solenoidal Tracker At RHIC) detector is pertinent for the RHIC (Relativi...

  6. Hadron production in deuteron-gold collisions and nuclear parton distributions

    Science.gov (United States)

    Adeluyi, Adeola; Fai, George

    2007-11-01

    We calculate nuclear modification factors RdAu, central-to-peripheral ratios, RCP, and pseudorapidity asymmetries YAsym in deuteron-gold collisions at s=200 GeV in the framework of leading-order (LO) perturbative quantum chromodynamics. We use the Eskola-Kolhinen-Salgado (EKS), the Frankfurt-Guzey-Strikman (FGS), and the Hirai-Kumano-Nagai (HKN) nuclear parton distribution functions and the Albino-Kramer-Kniehl (AKK) fragmentation functions in our calculations. Results are compared to experimental data from the BRAHMS and STAR collaborations.

  7. Nuclear Shadowing and Select d+Au Observables

    Science.gov (United States)

    Adeluyi, Adeola; Fai, George

    2007-04-01

    Much of the complexity of the description of d+Au collisions in the framework of perturbative Quantum Chromodynamics (pQCD) derives from effects of the nuclear environment. Here we investigate the effects of the most recent available nuclear shadowing parametrization, the Hirai-Kumano-Nagai (HKN) nuclear parton distribution functions (nPDFs) and the updated Albino-Kniehl-Kramer (AKK) fragmentation functions on three select d+Au collision observables. We compare our results to available experimental data from the STAR and BRAHMS collaborations.

  8. High-energy limit of quantum electrodynamics beyond Sudakov approximation

    Directory of Open Access Journals (Sweden)

    Alexander A. Penin

    2015-05-01

    Full Text Available We study the high-energy behavior of the scattering amplitudes in quantum electrodynamics beyond the leading order of the small electron mass expansion in the leading logarithmic approximation. In contrast to the Sudakov logarithms, the mass-suppressed double-logarithmic radiative corrections are induced by a soft electron pair exchange and result in enhancement of the power-suppressed contribution, which dominates the amplitudes at extremely high energies. Possible applications of our result to the analysis of the high-energy processes in quantum chromodynamics is also discussed.

  9. High-energy limit of quantum electrodynamics beyond Sudakov approximation

    Energy Technology Data Exchange (ETDEWEB)

    Penin, Alexander A., E-mail: penin@ualberta.ca [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Institut für Theoretische Teilchenphysik, Karlsruhe Institute of Technology, 76128 Karlsruhe (Germany)

    2015-05-18

    We study the high-energy behavior of the scattering amplitudes in quantum electrodynamics beyond the leading order of the small electron mass expansion in the leading logarithmic approximation. In contrast to the Sudakov logarithms, the mass-suppressed double-logarithmic radiative corrections are induced by a soft electron pair exchange and result in enhancement of the power-suppressed contribution, which dominates the amplitudes at extremely high energies. Possible applications of our result to the analysis of the high-energy processes in quantum chromodynamics is also discussed.

  10. Higgs Boson Mass in Supersymmetry to Three Loops

    International Nuclear Information System (INIS)

    Within the minimal supersymmetric extension of the standard model, the mass of the light CP-even Higgs boson is computed to three-loop accuracy, taking into account the next-to-next-to-leading order effects from supersymmetric quantum chromodynamics. We consider two different scenarios for the mass hierarchies of the supersymmetric spectrum. Our numerical results amount to corrections of about 500 MeV, which is of the same order as the experimental accuracy expected at the CERN Large Hadron Collider

  11. QCD emergent from spontaneous breakdown of relativity

    CERN Document Server

    Nishimura, Kimihide

    2016-01-01

    Spontaneous violation of relativistic invariance of the vacuum can derive quantum chromodynamics from an U(1) Higgs model including fermions, if the emergent theory is Lorentz invariant. In this model, the vacuum becomes anisotropic, and a fermion created on a triplet of spin-one vacua acquires degeneracy analogous to the color degrees of freedom. The Nambu-Goldstone bosons originating from the breakdown of rotational symmetry provide the quasi fermions with SU(3)$\\times$U(1) effective interactions, which are interpretable as mediated by gluons and photons. The confinement of quasi quarks as well as that of Nambu-Goldstone gluons follow from the Lorentz invariance of the emergent theory.

  12. Uncertainty quantification in lattice QCD calculations for nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Beane, Silas R. [Univ. of Washington, Seattle, WA (United States); Detmold, William [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Orginos, Kostas [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Savage, Martin J. [Institute for Nuclear Theory, Seattle, WA (United States)

    2015-02-05

    The numerical technique of Lattice QCD holds the promise of connecting the nuclear forces, nuclei, the spectrum and structure of hadrons, and the properties of matter under extreme conditions with the underlying theory of the strong interactions, quantum chromodynamics. A distinguishing, and thus far unique, feature of this formulation is that all of the associated uncertainties, both statistical and systematic can, in principle, be systematically reduced to any desired precision with sufficient computational and human resources. As a result, we review the sources of uncertainty inherent in Lattice QCD calculations for nuclear physics, and discuss how each is quantified in current efforts.

  13. The Crystal Barrel: Meson Spectroscopy at LEAR with a 4$\\pi$ Detector

    CERN Multimedia

    2002-01-01

    % PS197 \\\\ \\\\The Crystal Barrel is a 4$\\pi$ spectrometer designed to provide complete and precise information on practically every final state produced in $\\bar{p} p $ and $\\bar{p}d $ annihilations at low energy and to collect high statistics data samples. Selective triggers can be applied when necessary. \\\\ \\\\The physics goal is to identify all light mesons in the mass range from 0.14 to 2.3~GeV/c$^{2}$, to determine their quantum numbers and decay properties and to study the annihilation dynamics. The main interest is to find the glueball and hybrid degrees of freedom predicted in the framework of Quantum Chromodynamics. \\\\ \\\\\

  14. The GF11 supercomputer

    Science.gov (United States)

    Beetem, J.; Denneau, M.; Weingarten, D.

    1987-01-01

    GF11 is a parallel computer currently under construction at the IBM Yorktown Research Center. The machine incorporates 576 floating-point processors arranged in a modified SIMD architecture. Each has space for 2 Mbytes of memory and is capable of 20 Mflops, giving the total machine a peak of 1.125 Gbytes of memory and 11.52 Gflops. The floating-point processors are interconnected by a dynamically reconfigurable non-blocking switching network. At each machine cycle any of 1024 pre-selected permutations of data can be realized among the processors. The main intended application of GF11 is a class of calculations arising from quantum chromodynamics.

  15. Probing QCD at Medium Q^2

    CERN Document Server

    Hoyer, P

    2002-01-01

    Quantum Chromodynamics (QCD) is a firmly established part of the Standard Model, yet its long distance properties remain challenging at a conceptual level. In recent years significant experimental and theoretical progress has been made towards a field theoretic understanding of hadrons as QCD bound states, addressing the complex properties of relativistic bound states in a gluon condensate with spontaneously broken chiral symmetry. In this introductory talk I give a personal view of some of the issues involved: Measuring hadron matrix elements, understanding their QCD dynamics and explaining the apparently close relationship between hard and soft processes.

  16. Gluonic hadrons

    International Nuclear Information System (INIS)

    The standard theory of colour forces (Quantum Chromodynamics) suggests that in addition to the familiar hadrons made of quarks, there should exist new states where coloured gluons play an essential dynamical role. The author reviews the theoretical predictions for the properties of these ''glueballs'' and of states containing resonating quarks and gluons. Attempts are made to highlight those features which are common to several models in the literature. Experimental candidates are confronted with the models. No clear cut signal for a gluonic hadron yet exists; consequently what future data are required to determine the constituency of some popular candidates is considered. (author)

  17. Measurement of bottom versus charm as a function of transverse momentum with electron-hadron correlations in p + p collisions at square root of s = 200 GeV.

    Science.gov (United States)

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Aoki, K; Aphecetche, L; Armendariz, R; Aronson, S H; Asai, J; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Chang, B S; Chang, W C; Charvet, J-L; Chernichenko, S; Chiba, J; Chi, C Y; Chiu, M; Choi, I J; Choudhury, R K; Chujo, T; Chung, P; Churyn, A; Cianciolo, V; Citron, Z; Cleven, C R; Cole, B A; Comets, M P; Constantin, P; Csanád, M; Csörgo, T; Dahms, T; Dairaku, S; Das, K; David, G; Deaton, M B; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durum, A; Dutta, D; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Gustafsson, H-A; Hachiya, T; Henni, A Hadj; Haegemann, C; Haggerty, J S; Hamagaki, H; Han, R; Harada, H; Hartouni, E P; Haruna, K; Haslum, E; Hayano, R; Heffner, M; Hemmick, T K; Hester, T; He, X; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Inoue, Y; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Jacak, B V; Jia, J; Jin, J; Jinnouchi, O; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneta, M; Kang, J H; Kanou, H; Kapustinsky, J; Kawall, D; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, B I; Kim, D H; Kim, D J; Kim, E; Kim, S H; Kinney, E; Kiriluk, K; Kiss, A; Kistenev, E; Kiyomichi, A; Klay, J; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kozlov, A; Král, A; Kravitz, A; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y-S; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, D M; Lee, K B; Lee, M K; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Liebing, P; Liska, T; Litvinenko, A; Liu, H; Liu, M X; Li, X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mannel, E; Mao, Y; Masek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; Means, N; Meredith, B; Miake, Y; Mikes, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, M; Mitchell, J T; Mitrovski, M; Mohanty, A K; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Niita, T; Norman, B E; Nouicer, R; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Okada, H; Okada, K; Oka, M; Omiwade, O O; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roach, D; Roche, G; Rolnick, S D; Romana, A; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ruzicka, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Sakata, H; Samsonov, V; Sato, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Semenov, V; Seto, R; Sharma, D; Shein, I; Shevel, A; Shibata, T-A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skutnik, S; Slunecka, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarján, P; Themann, H; Thomas, T L; Togawa, M; Toia, A; Tojo, J; Tomásek, L; Tomita, Y; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Veicht, A; Velkovska, J; Vertesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D

    2009-08-21

    The momentum distribution of electrons from semileptonic decays of charm and bottom quarks for midrapidity |y|e(+/-)K(-/+)X (K unidentified) reconstruction. It is found that the yield of electrons from bottom becomes significant above 4 GeV/c in pT. A fixed-order-plus-next-to-leading-log perturbative quantum chromodynamics calculation agrees with the data within the theoretical and experimental uncertainties. The extracted total bottom production cross section at this energy is sigma(bb)=3.2(-1.1)(+1.2)(stat)(-1.3)(+1.4)(syst)mub.

  18. Measurement of Inclusive $\\omega$ and $\\eta$' Production in Hadronic Z Decays

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alpat, B; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Antreasyan, D; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banicz, K; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Borgia, B; Boucham, A; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Buytenhuijs, A O; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Caria, M; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chan, A; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Choi, M T; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; De Boeck, H; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dorne, I; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Fernández, D; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Janssen, H; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kuijten, H; Kunin, A; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee Jae Sik; Lee, K Y; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lieb, E H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Morganti, S; Moulik, T; Mount, R; Müller, S; Muheim, F; Nagy, E; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nippe, A; Nisati, A; Nowak, H; Opitz, H; Organtini, G; Ostonen, R; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Rahal-Callot, G; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riemers, B C; Riles, K; Rind, O; Ro, S; Robohm, A; Rodin, J; Rodríguez-Calonge, F J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Rykaczewski, H; Salicio, J; Sánchez, E; Santocchia, A; Sarakinos, M E; Sarkar, S; Sassowsky, M; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Sens, Johannes C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F

    1997-01-01

    We present a study of the inclusive $\\omega$ and $\\eta^{\\prime}$ production based on 3.1 million hadronic Z decays recorded with the L3 detector at LEP during 1991--1994. The production rates per hadronic Z decay have been measured to be $1.17 \\pm 0.17 $ $\\omega$ mesons and $0.25 \\pm 0.04 $ $\\eta^{\\prime}$ mesons. The production rates and the differential cross sections have been compared with predictions of the JETSET and the HERWIG Monte Carlo models. We have observed that the differential cross sections can be described by an analytical quantum chromodynamics calculation. \\end{document}

  19. Topology in dynamical lattice QCD simulations

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, Florian

    2012-08-20

    Lattice simulations of Quantum Chromodynamics (QCD), the quantum field theory which describes the interaction between quarks and gluons, have reached a point were contact to experimental data can be made. The underlying mechanisms, like chiral symmetry breaking or the confinement of quarks, are however still not understood. This thesis focuses on topological structures in the QCD vacuum. Those are not only mathematically interesting but also closely related to chiral symmetry and confinement. We consider methods to identify these objects in lattice QCD simulations. Based on this, we explore the structures resulting from different discretizations and investigate the effect of a very strong electromagnetic field on the QCD vacuum.

  20. Review of physics results from the Tevatron: QCD physics

    Energy Technology Data Exchange (ETDEWEB)

    Mesropian, Christina [Rockefeller U.; Bandurin, Dmitry [Virginia U.

    2015-02-17

    We present a summary of results from studies of quantum chromodynamics at the Fermilab Tevatron collider by the CDF and the D0 experiments. These include Run II results for the time period up to the end of Summer 2014. A brief description of Run I results is also given. This review covers a wide spectrum of topics, and includes measurements with jet and vector boson final states in the hard (perturbative) energy regime, as well as studies of soft physics such as diffractive and elastic scatterings, underlying and minimum bias events, hadron fragmentation, and multiple parton interactions.

  1. The 3-loop non-singlet heavy flavor contributions to the structure function g1(x,Q2 at large momentum transfer

    Directory of Open Access Journals (Sweden)

    A. Behring

    2015-08-01

    Full Text Available We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the polarized structure function g1(x,Q2 in the asymptotic region Q2≫m2 to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N and the momentum fraction x, and derive heavy flavor corrections to the Bjorken sum-rule. Numerical results are presented for the charm quark contribution. Results on the structure function g2(x,Q2 in the twist-2 approximation are also given.

  2. Single quark entropy and the Polyakov loop

    CERN Document Server

    Weber, Johannes Heinrich

    2016-01-01

    We study Quantum Chromodynamics (QCD) with 2+1 flavors with almost physical quark masses using the highly improved staggered quark action (HISQ). We calculate the Polyakov loop in a wide temperature range, obtain the free energy and the entropy of a single static quark and discuss the QCD crossover region in detail. We show that the entropy has a peak close to the chiral crossover and consider the consequences for the deconfinement aspects of the crossover phenomena. We study the renormalized Polyakov loop susceptibilities and place them into the context of the crossover. We also obtain a quantitative result for the onset of weak coupling behavior at high temperatures.

  3. Hot Quark Matter with an Axial Chemical Potential

    CERN Document Server

    Gatto, Raoul

    2011-01-01

    We analyze the phase diagram of hot quark matter in presence of an axial chemical potential, $\\mu_5$. The latter is introduced to mimic the chirality transitions induced, in hot Quantum Chromodynamics, by the strong sphaleron configurations. In particular, we study the curvature of the critical line at small $\\mu_5$, the effects of a finite quark mass and of a vector interaction. Moreover, we build the mixed phase at the first order phase transition line, and draw the phase diagram in the chiral density and temperature plane. We finally compute the full topological susceptibility in presence of a background of topological charge.

  4. Quarks, leptons, and beyond

    International Nuclear Information System (INIS)

    This volume is a compilation of the papers presented at the September 1983 NATO ASI Conference on Quarks and Leptons. Subjects covered include: physics results of the UAl collaboration at the CERN proton-antiproton collider, charged current mixing and CP-violation, lattice quantum chromodynamics, lattice gauge theory with matter, left-right symmetric models of weak interactions, extensions of the standard model, supersymmetry in particle physics, quasi nambu-Goldstone fermions, cosmology and particle physics, low energy theorem for the Goldstino, superstrings, different formulations of N=1 supergravity and model building, and supersymmetric GUTS

  5. Overview of nuclear structure with electrons

    Energy Technology Data Exchange (ETDEWEB)

    Geesaman, D. F.

    1999-12-03

    Following a broad summary of the author's view of nuclear structure in 1974, he will discuss the key elements they have learned in the past 25 years from the research at the M.I.T. Bates Linear Accelerator center and its sister electron accelerator laboratories. Electron scattering has provided the essential measurements for most of the progress. The future is bright for nuclear structure research as their ability to realistically calculate nuclear structure observables has dramatically advanced and they are increasingly able to incorporate an understanding of quantum chromodynamics into their picture of the nucleus.

  6. Quark-Gluon Plasma: from accelerator experiments to early Universe

    CERN Document Server

    Rosnet, P

    2015-01-01

    In the Big Bang scenario, the early Universe is characterized by the {\\it particle era}, i.e. a Universe made of particles. This period connects both scales of fundamental physics: infinitesimally small and infinitely large. So, particle physics and in particular experimental programs at accelerators can bring valuable inputs for the understanding of the early Universe and its evolution. These proceedings discuss the impact of the Quantum ChromoDynamics phase transition experienced by the {\\it particle era} in the expanding Universe, which is connected to the study of the Quark-Gluon Plasma produced in heavy-ion physics experiments.

  7. Double parton scattering in proton-proton collisions

    OpenAIRE

    Gaunt, Jonathan

    2012-01-01

    Double hard parton-parton interactions are expected to occur frequently in proton-proton (p-p) collisions at the LHC. They can give rise to significant backgrounds to certain rare single scattering (SPS) signals, and are an interesting signal process in their own right. In this thesis, we discuss the theoretical description of the double parton scattering (DPS) cross section in the context of Quantum ChromoDynamics (QCD). After an overview of QCD and an introduction to DPS in Chapter 1, w...

  8. NEW RESULTS FROM THE MUON G - 2 EXPERIMENT.

    Energy Technology Data Exchange (ETDEWEB)

    SICHTERMANN,E.P.BENNETT,G.W.BOUSQUET,B.BROWN,H.N.BUNCE,G.CAREY,R.M.ET ALMUON G - 2 COLLABORATION

    2002-09-09

    The Muon g-2 collaboration has measured the anomalous magnetic g value, a = (g-2)/2, of the positive muon with an unprecedented uncertainty of O.7parts per million. The result a{sub {mu}{sup +}}(expt) = 11 659 204(7)(5) x 10{sup -10}, based on data collected in the year 2000 at Brookhaven National Laboratory, is in good agreement with the preceding data on a{sub {mu}{sup +}} and a{sub {mu}{sup -}}. The measurement tests standard model theory, which at the level of the current experimental uncertainty involves quantum electrodynamics, quantum chromodynamics, and electroweak interaction in a significant way.

  9. Which Chiral Symmetry is Restored in High Temperature QCD?

    CERN Document Server

    Bernard, C W; DeTar, C E; Gottlieb, S; Heller, U M; Hetrick, J E; Rummukainen, K; Sugar, R; Toussaint, D; Wingate, M; Bernard, Claude; Blum, Tom; Tar, Carleton De; Gottlieb, Steven; Heller, Urs M.; Hetrick, James E.; Wingate, Matthew

    1996-01-01

    Sigma models for the high temperature phase transition in quantum chromodynamics (QCD) suggest that at high temperature the SU(N_f) x SU(N_f) chiral symmetry becomes exact, but the anomalous axial U(1) symmetry need not be restored. In numerical lattice simulations, traditional methods for detecting symmetry restoration have sought multiplets in the screening mass spectrum. However, these methods were imprecise and the results, so far, incomplete. With improved statistics and methodology, we are now able to offer evidence for a restoration of the SU(2) x SU(2) chiral symmetry just above the crossover, but not of the axial U(1) chiral symmetry.

  10. Critical Behavior in Nt = 4 Staggered Fermion Thermodynamics

    CERN Document Server

    Bernard, C W; Gottlieb, S; Heller, U M; Hetrick, J E; Rummukainen, K; Sugar, R L; Toussaint, D

    2000-01-01

    Quantum chromodynamics with two zero-mass flavors is expected to exhibit a phase transition with O(4) critical behavior. Fixing the universality class is important for phenomenology and for facilitating the extrapolation of simulation data to physical quark mass values. Other groups have reported results from lattice QCD simulations with dynamical staggered quarks at Nt = 4, which suggest a departure from the expected critical behavior. We have pushed simulations to the largest volumes and smallest quark mass to date. Strong discrepancies in critical exponents and the scaling equation of state persist.

  11. Critical Behavior at the Chiral Phase Transition

    CERN Document Server

    Bernard, C W; DeTar, C E; Gottlieb, S; Heller, U M; Hetrick, J E; Jegerlehner, B; Rummukainen, K; Sugar, R L; Toussaint, D; Wingate, M; Jegerlehner, Beat

    1998-01-01

    Quantum chromodynamics with two zero mass flavors is expected to exhibit a phase transition with O(4) critical behavior. Fixing the universality class is important for phenomenology and for facilitating the extrapolation of simulation data to physical quark mass values. At Lattice '96 the Tsukuba and Bielefeld groups reported results from new simulations with dynamical staggered quarks at $N_t = 4$, which suggested a departure from the expected critical behavior. We report observations of similar deviations and discuss efforts in progress to understand this phenomenon.

  12. Spin Polarized versus Chiral Condensate in Quark Matter at Finite Temperature and Density

    CERN Document Server

    Matsuoka, H; da Providencia, J; Providencia, C; Yamamura, M; Bohr, H

    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-Lasinio-type model as a low energy effective theory of quantum chromodynamics. It is indicated within this low energy effective model that the chiral symmetry is broken again by the spin polarized condensate as increasing the quark number density, while the chiral symmetry restoration occurs in which the chiral condensate disappears at a certain density.

  13. Relativistic corrections to the pair Bc-meson production in e+e- annihilation

    Science.gov (United States)

    Karyasov, A. A.; Martynenko, A. P.; Martynenko, F. A.

    2016-10-01

    Relativistic corrections to the pair Bc-meson production in e+e--annihilation are calculated. We investigate a production of pair pseudoscalar, vector and pseudoscalar+vector Bc-mesons in the leading order perturbative quantum chromodynamics and relativistic quark model. Relativistic expressions of the pair production cross sections are obtained. Their numerical evaluation shows that relativistic effects in the production amplitudes and bound state wave functions three times reduce nonrelativistic results at the center-of-mass energy s = 22 GeV.

  14. Quark Virtuality and QCD Vacuum Condensates

    Institute of Scientific and Technical Information of China (English)

    ZHOU Li-Juan; MA Wei-Xing

    2004-01-01

    @@ Based on the Dyson-Schwinger equations (DSEs) in the ‘rainbow' approximation, we investigate the quark virtuality in the vacuum state and quantum-chromodynamics (QCD) vacuum condensates. In particular, we calculate the local quark vacuum condensate and quark-gluon mixed condensates, and then the virtuality of quark. The calculated quark virtualities are λ2u,d = 0.7 GeV2 for u, d quarks, and 2s 1.6 GeV2 for s quark.Our theoretical predictions are consistent with empirical values used in QCD sum rules, and also fit to lattice QCD predictions.

  15. Top quark forward-backward asymmetry in e+ e- annihilation at next-to-next-to-leading order in QCD.

    Science.gov (United States)

    Gao, Jun; Zhu, Hua Xing

    2014-12-31

    We report on a complete calculation of electroweak production of top-quark pairs in e+ e- annihilation at next-to-next-to-leading order in quantum chromodynamics. Our setup is fully differential in phase space and can be used to calculate any infrared-safe observable. Especially we calculated the next-to-next-to-leading-order corrections to the top-quark forward-backward asymmetry and found sizable effects. Our results show a large reduction of the theoretical uncertainties in predictions of the forward-backward asymmetry, and allow for a precision determination of the top-quark electroweak couplings at future e+ e- colliders.

  16. Charm-Quark Production in Deep-Inelastic Neutrino Scattering at Next-to-Next-to-Leading Order in QCD.

    Science.gov (United States)

    Berger, Edmond L; Gao, Jun; Li, Chong Sheng; Liu, Ze Long; Zhu, Hua Xing

    2016-05-27

    We present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. We compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. Our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon.

  17. Top-quark pair production at next-to-next-to-leading order QCD in electron positron collisions

    CERN Document Server

    Chen, Long; Heisler, Dennis; Bernreuther, Werner; Si, Zong-Guo

    2016-01-01

    We set up a formalism, within the antenna subtraction framework, for computing the production of a massive quark-antiquark pair in electron positron collisions at next-to-next-to-leading order in the coupling $\\alpha_s$ of quantum chromodynamics at the differential level. Our formalism applies to the calculation of any infrared-safe observable. We apply this set-up to the production of top-quark top antiquark pairs in the continuum. We compute the production cross section and several distributions. We determine, in particular, the top-quark forward-backward asymmetry at order $\\alpha_s^2$. Our result agrees with previous computations of this observable.

  18. Fragmentation properties of jets produced in proton-antiproton collisions at √S = 1.8 TeV

    International Nuclear Information System (INIS)

    Jet fragmentation properties have been studied in collisions of protons and antiprotons at a center-of-mass energy of 1.8 TeV, using the Collider Detector at Fermilab (CDF). The fractional momentum distribution of charged particles within jets is presented and compared with Monte-Carlo predictions. With increasing di-jet invariant mass from 60 to 200 GeV/c2 the fragmentation is observed to soften as predicted by scale breaking effects in Quantum Chromodynamics (QCD). The charged multiplicity in the jet core is observed to rise with di-jet invariant mass. 57 refs

  19. Searching for the rules that govern hadron construction.

    Science.gov (United States)

    Shepherd, Matthew R; Dudek, Jozef J; Mitchell, Ryan E

    2016-06-23

    Just as quantum electrodynamics describes how electrons are bound in atoms by the electromagnetic force, mediated by the exchange of photons, quantum chromodynamics (QCD) describes how quarks are bound inside hadrons by the strong force, mediated by the exchange of gluons. QCD seems to allow hadrons constructed from increasingly many quarks to exist, just as atoms with increasing numbers of electrons exist, yet such complex constructions seemed, until recently, not to be present in nature. Here we describe advances in the spectroscopy of mesons that are refining our understanding of the rules for predicting hadron structure from QCD.

  20. Measurement of the Associated $\\gamma + \\mu^{\\pm}$ Production Cross Section in $p\\overline{p}$ Collisions at $\\sqrt{s} = 1.8 TeV$

    CERN Document Server

    Abe, F; Amendolia, S R; Amidei, D; Antos, J; Anway-Wiese, C; Apollinari, G; Areti, H; Atac, M; Auchincloss, P S; Azfar, F; Azzi, P; Bacchetta, N; Badgett, W; Bailey, M W; Bao, J; De Barbaro, P; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Bartalini, P; Bauer, G; Baumann, T; Bedeschi, F; Behrends, S; Belforte, S; Bellettini, G; Bellinger, J; Benjamin, D; Benlloch, J M; Bensinger, J; Benton, D; Beretvas, A; Bergé, J P; Bertolucci, Sergio; Bhatti, A A; Biery, K; Binkley, M; Bird, F; Bisello, D; Blair, R E; Blocker, C; Bodek, A; Bokhari, W; Bolognesi, V; Bortoletto, D; Boswell, C; Boulos, T; Brandenburg, G; Bromberg, C; Buckley-Geer, E; Budd, H S; Burkett, K; Busetto, G; Byon-Wagner, A; Byrum, K L; Cammerata, J; Campagnari, C; Campbell, M; Caner, A; Carithers, W; Carlsmith, D; Castro, A; Cen, Y; Cervelli, F; Chao, H Y; Chapman, J; Cheng, M T; Chiarelli, G; Chikamatsu, T; Chiou, C N; Christofek, L; Cihangir, S; Clark, A G; Cobal, M; Contreras, M; Conway, J; Cooper, J; Cordelli, M; Couyoumtzelis, C; Crane, D; Cunningham, J D; Daniels, T; De Jongh, F; Delchamps, S; Dell'Agnello, S; Dell'Orso, Mauro; Demortier, L; Denby, B; Deninno, M; Derwent, P F; Devlin, T; Dickson, M; Dittmann, J R; Donati, S; Drucker, R B; Dunn, A; Einsweiler, Kevin F; Elias, J E; Ely, R; Engels, E; Eno, S; Errede, D; Errede, S; Fan, Q; Farhat, B; Fiori, I; Flaugher, B; Foster, G W; Franklin, M; Frautschi, M; Freeman, J; Friedman, J; Frisch, H; Fry, A; Fuess, T A; Fukui, Y; Funaki, S; Gagliardi, G; Galeotti, S; Gallinaro, M; Garfinkel, A F; Geer, S; Gerdes, D W; Giannetti, P; Giokaris, N; Giromini, P; Gladney, L; Glenzinski, D A; Gold, M; González, J; Gordon, A; Goshaw, A T; Goulianos, K; Grassmann, H; Grewal, A; Groer, L; Grosso-Pilcher, C; Haber, C; Hahn, S R; Hamilton, R; Handler, R; Hans, R M; Hara, K; Harral, B; Harris, R M; Hauger, S A; Hauser, J; Hawk, C; Heinrich, J; Cronin-Hennessy, D; Hollebeek, R; Holloway, L; Hölscher, A; Hong, S; Houk, G; Hu, P; Huffman, B T; Hughes, R; Hurst, P; Huston, J; Huth, J; Hylen, J; Incagli, M; Incandela, J R; Iso, H; Jensen, H; Jessop, C P; Joshi, U; Kadel, R W; Kajfasz, E; Kamon, T; Kaneko, T; Kardelis, D A; Kasha, H; Kato, Y; Keeble, L; Kennedy, R D; Kephart, R; Kesten, P; Kestenbaum, David S; Keup, R M; Keutelian, H; Keyvan, F; Kim, D H; Kim, H S; Kim, S B; Kim, S H; Kim, Y K; Kirsch, L; Koehn, P; Kondo, K; Konigsberg, J; Kopp, S; Kordas, K; Koska, W; Kovács, E; Kowald, W; Krasberg, M; Kroll, J; Kruse, M; Kuhlmann, S E; Kuns, E; Laasanen, A T; Labanca, N; Lammel, S; Lamoureux, J I; LeCompte, T; Leone, S; Lewis, J D; Limon, P; Lindgren, M; Liss, T M; Lockyer, N; Loomis, C; Long, O; Loreti, M; Low, E H; Lü, J; Lucchesi, D; Luchini, C B; Lukens, P; Lys, J; Maas, P; Maeshima, K; Maghakian, A; Maksimovic, P; Mangano, Michelangelo L; Mansour, J; Mariotti, M; Marriner, J P; Martin, A; Matthews, J A J; Mattingly, R; McIntyre, P; Mélèse, P; Menzione, A; Meschi, E; Michail, G; Mikamo, S; Miller, M; Miller, R; Mimashi, T; Miscetti, S; Mishina, M; Mitsushio, H; Miyashita, S; Morita, Y; Moulding, S; Müller, J; Mukherjee, A; Müller, T; Musgrave, P; Nakae, L F; Nakano, I; Nelson, C; Neuberger, D; Newman-Holmes, C; Nodulman, L; Ogawa, S; Oh, S H; Ohl, K E; Oishi, R; Okusawa, T; Pagliarone, C; Paoletti, R; Papadimitriou, V; Pappas, S P; Park, S; Patrick, J; Pauletta, G; Paulini, M; Pescara, L; Peters, M D; Phillips, T J; Piacentino, G; Pillai, M; Plunkett, R; Pondrom, L; Produit, N; Proudfoot, J; Ptohos, F; Punzi, G; Ragan, K; Rimondi, F; Ristori, L; Roach-Bellino, M; Robertson, W J; Rodrigo, T; Romano, J; Rosenson, L; Sakumoto, W K; Saltzberg, D; Sansoni, A; Scarpine, V; Schindler, A; Schlabach, P; Schmidt, E E; Schmidt, M P; Schneider, O; Sciacca, G F; Scribano, A; Segler, S; Seidel, S; Seiya, Y; Sganos, G; Sgolacchia, A; Shapiro, M; Shaw, N M; Shen, Q; Shepard, P F; Shimojima, M; Shochet, M; Siegrist, J; Sill, A; Sinervo, P; Singh, P; Skarha, J E; Sliwa, K; Smith, D A; Snider, F D; Song, L; Song, T; Spalding, J; Spiegel, L; Sphicas, Paris; Stanco, L; Steele, J; Stefanini, A; Strahl, K; Strait, J B; Stuart, D; Sullivan, G; Sumorok, K; Swartz, R L; Takahashi, T; Takikawa, K; Tartarelli, F; Taylor, W; Teng, P K; Teramoto, Y; Tether, S; Theriot, D; Thomas, J; Thomas, T L; Thun, R; Timko, M; Tipton, P; Titov, A; Tkaczyk, S; Tollefson, K; Tollestrup, Alvin V; Tonnison, J; De Trocóniz, J F; Tseng, J; Turcotte, M; Turini, N; Uemura, N; Ukegawa, F; Unal, G; van den Brink, S C; Vejcik, S; Vidal, R; Vondracek, M; Vucinic, D; Wagner, R G; Wagner, R L; Wainer, N; Walker, R C; Wang, C; Wang, C H; Wang, G; Wang, J; Wang, M J; Wang, Q F; Warburton, A; Watts, G; Watts, T; Webb, R; Wei, C; Wendt, C; Wenzel, H; Wester, W C; Westhusing, T; Wicklund, A B; Wicklund, E; Wilkinson, R; Williams, H H; Wilson, P; Winer, B L; Wolinski, J; Wu, D Y; Wu, X; Wyss, J; Yagil, A; Yao, W; Yasuoka, K; Ye, Y; Yeh, G P; Yeh, P; Yin, M; Yoh, J; Yosef, C; Yoshida, T; Yovanovitch, D; Yu, I; Yun, J C; Zanetti, A; Zetti, F; Zhang, L; Zhang, S; Zhang, W; Zucchelli, S

    1999-01-01

    We present the first measurement of associated direct photon + muon production in hadronic collisions, from a sample of 1.8 TeV $p \\bar p$ collisions recorded with the Collider Detector at Fermilab. Quantum chromodynamics (QCD) predicts that these events are primarily from the Compton scattering process $cg \\to c\\gamma$, with the final state charm quark producing a muon. Hence this measurement is sensitive to the charm quark content of the proton. The measured cross section of $29\\pm 9 pb^{-1}$ is compared to a leading-order QCD parton shower model as well as a next-to-leading-order QCD calculation.

  1. Annihilation physics of exotic galactic dark matter particles

    Science.gov (United States)

    Stecker, F. W.

    1990-01-01

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

  2. Massive Photons: An Infrared Regularization Scheme for Lattice QCD +QED

    Science.gov (United States)

    Endres, Michael G.; Shindler, Andrea; Tiburzi, Brian C.; Walker-Loud, André

    2016-08-01

    Standard methods for including electromagnetic interactions in lattice quantum chromodynamics calculations result in power-law finite-volume corrections to physical quantities. Removing these by extrapolation requires costly computations at multiple volumes. We introduce a photon mass to alternatively regulate the infrared, and rely on effective field theory to remove its unphysical effects. Electromagnetic modifications to the hadron spectrum are reliably estimated with a precision and cost comparable to conventional approaches that utilize multiple larger volumes. A significant overall cost advantage emerges when accounting for ensemble generation. The proposed method may benefit lattice calculations involving multiple charged hadrons, as well as quantum many-body computations with long-range Coulomb interactions.

  3. Study of hadronic event-shape variables in multijet final states in pp collisions at $\\sqrt{s}$ = 7 TeV

    CERN Document Server

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Knünz, Valentin; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Bansal, Monika; Bansal, Sunil; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Luyckx, Sten; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Daci, Nadir; Heracleous, Natalie; Kalogeropoulos, Alexis; Keaveney, James; Kim, Tae Jeong; Lowette, Steven; Maes, Michael; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Dobur, Didar; Favart, Laurent; Gay, Arnaud; Grebenyuk, Anastasia; Léonard, Alexandre; Mohammadi, Abdollah; Perniè, Luca; Reis, Thomas; Seva, Tomislav; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wang, Jian; Adler, Volker; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Costantini, Silvia; Crucy, Shannon; Dildick, Sven; Fagot, Alexis; Garcia, Guillaume; Klein, Benjamin; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bruno, Giacomo; Castello, Roberto; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Liao, Junhui; Nuttens, Claude; Pagano, Davide; Perrini, Lucia; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Vizan Garcia, Jesus Manuel; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Hammad, Gregory Habib; Aldá Júnior, Walter Luiz; Alves, Gilvan; Correa Martins Junior, Marcos; Dos Reis Martins, Thiago; Pol, Maria Elena; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Da Costa, Eliza Melo; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Malbouisson, Helena; Malek, Magdalena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santaolalla, Javier; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Bernardes, Cesar Augusto; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Aleksandrov, Aleksandar; Genchev, Vladimir; Iaydjiev, Plamen; Marinov, Andrey; Piperov, Stefan; Rodozov, Mircho; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Du, Ran; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Plestina, Roko; Tao, Junquan; Wang, Xianyou; Wang, Zheng; Asawatangtrakuldee, Chayanit; Ban, Yong; Guo, Yifei; Li, Qiang; Li, Wenbo; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Zhang, Linlin; Zou, Wei; Avila, Carlos; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Mekterovic, Darko; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Ellithi Kamel, Ali; Mahmoud, Mohammed; Radi, Amr; Kadastik, Mario; Murumaa, Marion; Raidal, Martti; Tiko, Andres; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Rander, John; Rosowsky, André; Titov, Maksym; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Charlot, Claude; Dahms, Torsten; Dalchenko, Mykhailo; Dobrzynski, Ludwik; Filipovic, Nicolas; Florent, Alice; Granier de Cassagnac, Raphael; Mastrolorenzo, Luca; Miné, Philippe; Mironov, Camelia; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Paganini, Pascal; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Veelken, Christian; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Goetzmann, Christophe; Le Bihan, Anne-Catherine; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Beaupere, Nicolas; Boudoul, Gaelle; Brochet, Sébastien; Carrillo Montoya, Camilo Andres; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Kurca, Tibor; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Ruiz Alvarez, José David; Sabes, David; Sgandurra, Louis; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Xiao, Hong; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Bontenackels, Michael; Edelhoff, Matthias; Feld, Lutz; Hindrichs, Otto; Klein, Katja; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Dietz-Laursonn, Erik; Duchardt, Deborah; Erdmann, Martin; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Knutzen, Simon; Kreuzer, Peter; Merschmeyer, Markus; Meyer, Arnd; Olschewski, Mark; Padeken, Klaas; Papacz, Paul; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Weber, Martin; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Haj Ahmad, Wael; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Lingemann, Joschka; Nowack, Andreas; Nugent, Ian Michael; Perchalla, Lars; Pooth, Oliver; Stahl, Achim; Asin, Ivan; Bartosik, Nazar; Behr, Joerg; Behrenhoff, Wolf; Behrens, Ulf; Bell, Alan James; Bergholz, Matthias; Bethani, Agni; Borras, Kerstin; Burgmeier, Armin; Cakir, Altan; Calligaris, Luigi; Campbell, Alan; Choudhury, Somnath; Costanza, Francesco; Diez Pardos, Carmen; Dooling, Samantha; Dorland, Tyler; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Flucke, Gero; Garay Garcia, Jasone; Geiser, Achim; Gunnellini, Paolo; Hauk, Johannes; Hellwig, Gregor; Hempel, Maria; Horton, Dean; Jung, Hannes; Kasemann, Matthias; Katsas, Panagiotis; Kieseler, Jan; Kleinwort, Claus; Krücker, Dirk; Lange, Wolfgang; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Lutz, Benjamin; Mankel, Rainer; Marfin, Ihar; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Nayak, Aruna; Novgorodova, Olga; Nowak, Friederike; Ntomari, Eleni; Perrey, Hanno; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Ribeiro Cipriano, Pedro M; Ron, Elias; Sahin, Mehmet Özgür; Salfeld-Nebgen, Jakob; Saxena, Pooja; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Schröder, Matthias; Spannagel, Simon; Vargas Trevino, Andrea Del Rocio; Walsh, Roberval; Wissing, Christoph; Aldaya Martin, Maria; Blobel, Volker; Centis Vignali, Matteo; Erfle, Joachim; Garutti, Erika; Goebel, Kristin; Görner, Martin; Gosselink, Martijn; Haller, Johannes; Hoffmann, Malte; Höing, Rebekka Sophie; Kirschenmann, Henning; Klanner, Robert; Kogler, Roman; Lange, Jörn; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Ott, Jochen; Peiffer, Thomas; Pietsch, Niklas; Rathjens, Denis; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Seidel, Markus; Poehlsen, Jennifer; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Barth, Christian; Baus, Colin; Berger, Joram; Böser, Christian; Butz, Erik; Chwalek, Thorsten; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Feindt, Michael; Frensch, Felix; Giffels, Manuel; Hartmann, Frank; Hauth, Thomas; Husemann, Ulrich; Katkov, Igor; Kornmayer, Andreas; Kuznetsova, Ekaterina; Lobelle Pardo, Patricia; Mozer, Matthias Ulrich; Müller, Thomas; Nürnberg, Andreas; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Röcker, Steffen; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weiler, Thomas; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Markou, Athanasios; Markou, Christos; Psallidas, Andreas; Topsis-Giotis, Iasonas; Panagiotou, Apostolos; Saoulidou, Niki; Stiliaris, Efstathios; Aslanoglou, Xenofon; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Bencze, Gyorgy; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Swain, Sanjay Kumar; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Gupta, Ruchi; Kalsi, Amandeep Kaur; Kaur, Manjit; Mittal, Monika; Nishu, Nishu; Singh, Jasbir; Kumar, Ashok; Kumar, Arun; Ahuja, Sudha; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Varun; Banerjee, Sunanda; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dutta, Suchandra; Gomber, Bhawna; Jain, Sandhya; Jain, Shilpi; Khurana, Raman; Modak, Atanu; Mukherjee, Swagata; Roy, Debarati; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Dutta, Dipanwita; Kailas, Swaminathan; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Banerjee, Sudeshna; Bhowmik, Sandeep; Chatterjee, Rajdeep Mohan; Dewanjee, Ram Krishna; Dugad, Shashikant; Ganguly, Sanmay; Ghosh, Saranya; Guchait, Monoranjan; Gurtu, Atul; Kole, Gouranga; Kumar, Sanjeev; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Parida, Bibhuti; Sudhakar, Katta; Wickramage, Nadeesha; Bakhshiansohi, Hamed; Behnamian, Hadi; Etesami, Seyed Mohsen; Fahim, Ali; Goldouzian, Reza; Jafari, Abideh; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Chhibra, Simranjit Singh; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Selvaggi, Giovanna; Silvestris, Lucia; Singh, Gurpreet; Venditti, Rosamaria; Verwilligen, Piet; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gallo, Elisabetta; Gonzi, Sandro; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Ferro, Fabrizio; Lo Vetere, Maurizio; Robutti, Enrico; Tosi, Silvano; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Gerosa, Raffaele; Ghezzi, Alessio; Govoni, Pietro; Lucchini, Marco Toliman; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Martelli, Arabella; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Biasotto, Massimo; Branca, Antonio; Dall'Osso, Martino; Dorigo, Tommaso; Dosselli, Umberto; Fanzago, Federica; Galanti, Mario; Gasparini, Fabrizio; Giubilato, Piero; Gonella, Franco; Gozzelino, Andrea; Kanishchev, Konstantin; Lacaprara, Stefano; Margoni, Martino; Montecassiano, Fabio; Passaseo, Marina; Pazzini, Jacopo; Pegoraro, Matteo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Zotto, Pierluigi; Zucchetta, Alberto; Ratti, Sergio P; Riccardi, Cristina; Salvini, Paola; Vitulo, Paolo; Biasini, Maurizio; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Romeo, Francesco; Saha, Anirban; Santocchia, Attilio; Spiezia, Aniello; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Moon, Chang-Seong; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Serban, Alin Titus; Spagnolo, Paolo; Squillacioti, Paola; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Vernieri, Caterina; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Diemoz, Marcella; Grassi, Marco; Jorda, Clara; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Micheli, Francesco; Nourbakhsh, Shervin; Organtini, Giovanni; Paramatti, Riccardo; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Soffi, Livia; Traczyk, Piotr; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Casasso, Stefano; Costa, Marco; Degano, Alessandro; Demaria, Natale; Finco, Linda; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Ortona, Giacomo; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Potenza, Alberto; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Tamponi, Umberto; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; La Licata, Chiara; Marone, Matteo; Montanino, Damiana; Schizzi, Andrea; Umer, Tomo; Zanetti, Anna; Chang, Sunghyun; Kropivnitskaya, Anna; Nam, Soon-Kwon; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Kong, Dae Jung; Lee, Sangeun; Oh, Young Do; Park, Hyangkyu; Sakharov, Alexandre; Son, Dong-Chul; Kim, Jae Yool; Song, Sanghyeon; Choi, Suyong; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Yongsun; Lee, Byounghoon; Lee, Kyong Sei; Park, Sung Keun; Roh, Youn; Choi, Minkyoo; Kim, Ji Hyun; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Ryu, Min Sang; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kwon, Eunhyang; Lee, Jongseok; Seo, Hyunkwan; Yu, Intae; Juodagalvis, Andrius; Komaragiri, Jyothsna Rani; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-de La Cruz, Ivan; Lopez-Fernandez, Ricardo; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Reucroft, Steve; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khalid, Shoaib; Khan, Wajid Ali; Khurshid, Taimoor; Shah, Mehar Ali; Shoaib, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michał; Wolszczak, Weronika; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Varela, Joao; Vischia, Pietro; Golutvin, Igor; Karjavin, Vladimir; Konoplyanikov, Viktor; Korenkov, Vladimir; Kozlov, Guennady; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Mitsyn, Valeri Valentinovitch; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Tikhonenko, Elena; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Safronov, Grigory; Semenov, Sergey; Spiridonov, Alexander; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Vinogradov, Alexey; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Snigirev, Alexander; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Dordevic, Milos; Ekmedzic, Marko; Milosevic, Jovan; Alcaraz Maestre, Juan; Battilana, Carlo; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Merino, Gonzalo; Navarro De Martino, Eduardo; Pérez Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Soares, Mara Senghi; Albajar, Carmen; de Trocóniz, Jorge F; Missiroli, Marino; Brun, Hugues; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Duarte Campderros, Jordi; Fernandez, Marcos; Gomez, Gervasio; Graziano, Alberto; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benaglia, Andrea; Bendavid, Joshua; Benhabib, Lamia; Benitez, Jose F; Bernet, Colin; Bianchi, Giovanni; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Bondu, Olivier; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Cerminara, Gianluca; Colafranceschi, Stefano; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; David Tinoco Mendes, Andre; De Guio, Federico; De Roeck, Albert; De Visscher, Simon; Dobson, Marc; Dupont-Sagorin, Niels; Elliott-Peisert, Anna; Eugster, Jürg; Franzoni, Giovanni; Funk, Wolfgang; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Girone, Maria; Glege, Frank; Guida, Roberto; Gundacker, Stefan; Guthoff, Moritz; Hammer, Josef; Hansen, Magnus; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Kousouris, Konstantinos; Krajczar, Krisztian; Lecoq, Paul; Lourenco, Carlos; Magini, Nicolo; Malgeri, Luca; Mannelli, Marcello; Marrouche, Jad; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moortgat, Filip; Morovic, Srecko; Mulders, Martijn; Musella, Pasquale; Orsini, Luciano; Pape, Luc; Perez, Emmanuelle; Perrozzi, Luca; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Piparo, Danilo; Plagge, Michael; Racz, Attila; Rolandi, Gigi; Rovere, Marco; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Sekmen, Sezen; Sharma, Archana; Siegrist, Patrice; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Steggemann, Jan; Stieger, Benjamin; Stoye, Markus; Treille, Daniel; Tsirou, Andromachi; Veres, Gabor Istvan; Vlimant, Jean-Roch; Wardle, Nicholas; Wöhri, Hermine Katharina; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Renker, Dieter; Rohe, Tilman; Bachmair, Felix; Bäni, Lukas; Bianchini, Lorenzo; Bortignon, Pierluigi; Buchmann, Marco-Andrea; Casal, Bruno; Chanon, Nicolas; Deisher, Amanda; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Dünser, Marc; Eller, Philipp; Grab, Christoph; Hits, Dmitry; Lustermann, Werner; Mangano, Boris; Marini, Andrea Carlo; Martinez Ruiz del Arbol, Pablo; Meister, Daniel; Mohr, Niklas; Nägeli, Christoph; Nef, Pascal; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pauss, Felicitas; Peruzzi, Marco; Quittnat, Milena; Rebane, Liis; Ronga, Frederic Jean; Rossini, Marco; Starodumov, Andrei; Takahashi, Maiko; Theofilatos, Konstantinos; Wallny, Rainer; Weber, Hannsjoerg Artur; Amsler, Claude; Canelli, Maria Florencia; Chiochia, Vincenzo; De Cosa, Annapaola; Hinzmann, Andreas; Hreus, Tomas; Ivova Rikova, Mirena; Kilminster, Benjamin; Millan Mejias, Barbara; Ngadiuba, Jennifer; Robmann, Peter; Snoek, Hella; Taroni, Silvia; Verzetti, Mauro; Yang, Yong; Cardaci, Marco; Chen, Kuan-Hsin; Ferro, Cristina; Kuo, Chia-Ming; Lin, Willis; Lu, Yun-Ju; Volpe, Roberta; Yu, Shin-Shan; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Chen, Po-Hsun; Dietz, Charles; Grundler, Ulysses; Hou, George Wei-Shu; Kao, Kai-Yi; Lei, Yeong-Jyi; Liu, Yueh-Feng; Lu, Rong-Shyang; Majumder, Devdatta; Petrakou, Eleni; Tzeng, Yeng-Ming; Wilken, Rachel; Asavapibhop, Burin; Srimanobhas, Norraphat; Suwonjandee, Narumon; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Kayis Topaksu, Aysel; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sogut, Kenan; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Vergili, Mehmet; Akin, Ilina Vasileva; Bilin, Bugra; Bilmis, Selcuk; Gamsizkan, Halil; Karapinar, Guler; Ocalan, Kadir; Surat, Ugur Emrah; Yalvac, Metin; Zeyrek, Mehmet; Gülmez, Erhan; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Bahtiyar, Hüseyin; Barlas, Esra; Cankocak, Kerem; Vardarlı, Fuat Ilkehan; Yücel, Mete; Levchuk, Leonid; Sorokin, Pavel; Brooke, James John; Clement, Emyr; Cussans, David; Flacher, Henning; Frazier, Robert; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Jacob, Jeson; Kreczko, Lukasz; Lucas, Chris; Meng, Zhaoxia; Newbold, Dave M; Paramesvaran, Sudarshan; Poll, Anthony; Senkin, Sergey; Smith, Vincent J; Williams, Thomas; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Olaiya, Emmanuel; Petyt, David; Shepherd-Themistocleous, Claire; Thea, Alessandro; Tomalin, Ian R; Womersley, William John; Worm, Steven; Baber, Mark; Bainbridge, Robert; Buchmuller, Oliver; Burton, Darren; Colling, David; Cripps, Nicholas; Cutajar, Michael; Dauncey, Paul; Davies, Gavin; Della Negra, Michel; Dunne, Patrick; Ferguson, William; Fulcher, Jonathan; Futyan, David; Gilbert, Andrew; Hall, Geoffrey; Iles, Gregory; Jarvis, Martyn; Karapostoli, Georgia; Kenzie, Matthew; Lane, Rebecca; Lucas, Robyn; Lyons, Louis; Magnan, Anne-Marie; Malik, Sarah; Mathias, Bryn; Nash, Jordan; Nikitenko, Alexander; Pela, Joao; Pesaresi, Mark; Petridis, Konstantinos; Raymond, David Mark; Rogerson, Samuel; Rose, Andrew; Seez, Christopher; Sharp, Peter; Tapper, Alexander; Vazquez Acosta, Monica; Virdee, Tejinder; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Leggat, Duncan; Leslie, Dawn; Martin, William; Reid, Ivan; Symonds, Philip; Teodorescu, Liliana; Turner, Mark; Dittmann, Jay; Hatakeyama, Kenichi; Kasmi, Azeddine; Liu, Hongxuan; Scarborough, Tara; Charaf, Otman; Cooper, Seth; Henderson, Conor; Rumerio, Paolo; Avetisyan, Aram; Bose, Tulika; Fantasia, Cory; Heister, Arno; Lawson, Philip; Richardson, Clint; Rohlf, James; Sperka, David; St John, Jason; Sulak, Lawrence; Alimena, Juliette; Bhattacharya, Saptaparna; Christopher, Grant; Cutts, David; Demiragli, Zeynep; Ferapontov, Alexey; Garabedian, Alex; Heintz, Ulrich; Jabeen, Shabnam; Kukartsev, Gennadiy; Laird, Edward; Landsberg, Greg; Luk, Michael; Narain, Meenakshi; Segala, Michael; Sinthuprasith, Tutanon; Speer, Thomas; Swanson, Joshua; Breedon, Richard; Breto, Guillermo; Calderon De La Barca Sanchez, Manuel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Erbacher, Robin; Gardner, Michael; Ko, Winston; Lander, Richard; Miceli, Tia; Mulhearn, Michael; Pellett, Dave; Pilot, Justin; Ricci-Tam, Francesca; Searle, Matthew; Shalhout, Shalhout; Smith, John; Squires, Michael; Stolp, Dustin; Tripathi, Mani; Wilbur, Scott; Yohay, Rachel; Cousins, Robert; Everaerts, Pieter; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Rakness, Gregory; Takasugi, Eric; Valuev, Vyacheslav; Weber, Matthias; Babb, John; Clare, Robert; Ellison, John Anthony; Gary, J William; Hanson, Gail; Heilman, Jesse; Jandir, Pawandeep; Kennedy, Elizabeth; Lacroix, Florent; Liu, Hongliang; Long, Owen Rosser; Luthra, Arun; Malberti, Martina; Nguyen, Harold; Shrinivas, Amithabh; Sumowidagdo, Suharyo; Wimpenny, Stephen; Andrews, Warren; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; D'Agnolo, Raffaele Tito; Evans, David; Holzner, André; Kelley, Ryan; Klein, Daniel; Lebourgeois, Matthew; Letts, James; Macneill, Ian; Olivito, Dominick; Padhi, Sanjay; Palmer, Christopher; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Sudano, Elizabeth; Tadel, Matevz; Tu, Yanjun; Vartak, Adish; Welke, Charles; Würthwein, Frank; Yagil, Avraham; Yoo, Jaehyeok; Barge, Derek; Bradmiller-Feld, John; Campagnari, Claudio; Danielson, Thomas; Dishaw, Adam; Flowers, Kristen; Franco Sevilla, Manuel; Geffert, Paul; George, Christopher; Golf, Frank; Gouskos, Loukas; Incandela, Joe; Justus, Christopher; Mccoll, Nickolas; Richman, Jeffrey; Stuart, David; To, Wing; West, Christopher; Apresyan, Artur; Bornheim, Adolf; Bunn, Julian; Chen, Yi; Di Marco, Emanuele; Duarte, Javier; Mott, Alexander; Newman, Harvey B; Pena, Cristian; Rogan, Christopher; Spiropulu, Maria; Timciuc, Vladlen; Wilkinson, Richard; Xie, Si; Zhu, Ren-Yuan; Azzolini, Virginia; Calamba, Aristotle; Ferguson, Thomas; Iiyama, Yutaro; Paulini, Manfred; Russ, James; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Drell, Brian Robert; Ford, William T; Gaz, Alessandro; Luiggi Lopez, Eduardo; Nauenberg, Uriel; Smith, James; Stenson, Kevin; Ulmer, Keith; Wagner, Stephen Robert; Alexander, James; Chatterjee, Avishek; Chu, Jennifer; Dittmer, Susan; Eggert, Nicholas; Hopkins, Walter; Mirman, Nathan; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Ryd, Anders; Salvati, Emmanuele; Skinnari, Louise; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Tucker, Jordan; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Burkett, Kevin; Butler, Joel Nathan; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gao, Yanyan; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Hanlon, Jim; Hare, Daryl; Harris, Robert M; Hirschauer, James; Hooberman, Benjamin; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Kaadze, Ketino; Klima, Boaz; Kreis, Benjamin; Kwan, Simon; Linacre, Jacob; Lincoln, Don; Lipton, Ron; Liu, Tiehui; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Martinez Outschoorn, Verena Ingrid; Maruyama, Sho; Mason, David; McBride, Patricia; Mishra, Kalanand; Mrenna, Stephen; Musienko, Yuri; Nahn, Steve; Newman-Holmes, Catherine; O'Dell, Vivian; Prokofyev, Oleg; Sexton-Kennedy, Elizabeth; Sharma, Seema; Soha, Aron; Spalding, William J; Spiegel, Leonard; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitbeck, Andrew; Whitmore, Juliana; Yang, Fan; Acosta, Darin; Avery, Paul; Bourilkov, Dimitri; Carver, Matthew; Cheng, Tongguang; Curry, David; Das, Souvik; De Gruttola, Michele; Di Giovanni, Gian Piero; Field, Richard D; Fisher, Matthew; Furic, Ivan-Kresimir; Hugon, Justin; Konigsberg, Jacobo; Korytov, Andrey; Kypreos, Theodore; Low, Jia Fu; Matchev, Konstantin; Milenovic, Predrag; Mitselmakher, Guenakh; Muniz, Lana; Rinkevicius, Aurelijus; Shchutska, Lesya; Skhirtladze, Nikoloz; Snowball, Matthew; Yelton, John; Zakaria, Mohammed; Gaultney, Vanessa; Hewamanage, Samantha; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Diamond, Brendan; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Prosper, Harrison; Veeraraghavan, Venkatesh; Weinberg, Marc; Baarmand, Marc M; Hohlmann, Marcus; Kalakhety, Himali; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Bazterra, Victor Eduardo; Berry, Douglas; Betts, Russell Richard; Bucinskaite, Inga; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Khalatyan, Samvel; Kurt, Pelin; Moon, Dong Ho; O'Brien, Christine; Silkworth, Christopher; Turner, Paul; Varelas, Nikos; Albayrak, Elif Asli; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Duru, Firdevs; Haytmyradov, Maksat; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Rahmat, Rahmat; Sen, Sercan; Tan, Ping; Tiras, Emrah; Wetzel, James; Yetkin, Taylan; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bolognesi, Sara; Fehling, David; Gritsan, Andrei; Maksimovic, Petar; Martin, Christopher; Swartz, Morris; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Bruner, Christopher; Gray, Julia; Kenny III, Raymond Patrick; Murray, Michael; Noonan, Daniel; Sanders, Stephen; Sekaric, Jadranka; Stringer, Robert; Wang, Quan; Wood, Jeffrey Scott; Barfuss, Anne-Fleur; Chakaberia, Irakli; Ivanov, Andrew; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Saini, Lovedeep Kaur; Shrestha, Shruti; Svintradze, Irakli; Gronberg, Jeffrey; Lange, David; Rebassoo, Finn; Wright, Douglas; Baden, Drew; Calvert, Brian; Eno, Sarah Catherine; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G; Kolberg, Ted; Lu, Ying; Marionneau, Matthieu; Mignerey, Alice; Pedro, Kevin; Skuja, Andris; Tonjes, Marguerite; Tonwar, Suresh C; Apyan, Aram; Barbieri, Richard; Bauer, Gerry; Busza, Wit; Cali, Ivan Amos; Chan, Matthew; Di Matteo, Leonardo; Dutta, Valentina; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Gulhan, Doga; Klute, Markus; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Ma, Teng; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Stephans, George; Stöckli, Fabian; Sumorok, Konstanty; Velicanu, Dragos; Veverka, Jan; Wyslouch, Bolek; Yang, Mingming; Zanetti, Marco; Zhukova, Victoria; Dahmes, Bryan; De Benedetti, Abraham; Gude, Alexander; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Pastika, Nathaniel; Rusack, Roger; Singovsky, Alexander; Tambe, Norbert; Turkewitz, Jared; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bloom, Kenneth; Bose, Suvadeep; Claes, Daniel R; Dominguez, Aaron; Gonzalez Suarez, Rebeca; Keller, Jason; Knowlton, Dan; Kravchenko, Ilya; Lazo-Flores, Jose; Malik, Sudhir; Meier, Frank; Snow, Gregory R; Dolen, James; Godshalk, Andrew; Iashvili, Ia; Kharchilava, Avto; Kumar, Ashish; Rappoccio, Salvatore; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Haley, Joseph; Massironi, Andrea; Morse, David Michael; Nash, David; Orimoto, Toyoko; Trocino, Daniele; Wang, Ren-Jie; Wood, Darien; Zhang, Jinzhong; Hahn, Kristan Allan; Kubik, Andrew; Mucia, Nicholas; Odell, Nathaniel; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael; Stoynev, Stoyan; Sung, Kevin; Velasco, Mayda; Won, Steven; Brinkerhoff, Andrew; Chan, Kwok Ming; Drozdetskiy, Alexey; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Luo, Wuming; Lynch, Sean; Marinelli, Nancy; Pearson, Tessa; Planer, Michael; Ruchti, Randy; Valls, Nil; Wayne, Mitchell; Wolf, Matthias; Woodard, Anna; Antonelli, Louis; Brinson, Jessica; Bylsma, Ben; Durkin, Lloyd Stanley; Flowers, Sean; Hill, Christopher; Hughes, Richard; Kotov, Khristian; Ling, Ta-Yung; Puigh, Darren; Rodenburg, Marissa; Smith, Geoffrey; Vuosalo, Carl; Winer, Brian L; Wolfe, Homer; Wulsin, Howard Wells; Berry, Edmund; Driga, Olga; Elmer, Peter; Hebda, Philip; Hunt, Adam; Koay, Sue Ann; Lujan, Paul; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zenz, Seth Conrad; Zuranski, Andrzej; Brownson, Eric; Mendez, Hector; Ramirez Vargas, Juan Eduardo; Alagoz, Enver; Barnes, Virgil E; Benedetti, Daniele; Bolla, Gino; Bortoletto, Daniela; De Mattia, Marco; Hu, Zhen; Jha, Manoj; Jones, Matthew; Jung, Kurt; Kress, Matthew; Leonardo, Nuno; Lopes Pegna, David; Maroussov, Vassili; Merkel, Petra; Miller, David Harry; Neumeister, Norbert; Radburn-Smith, Benjamin Charles; Shi, Xin; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Wang, Fuqiang; Xie, Wei; Xu, Lingshan; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Parashar, Neeti; Stupak, John; Adair, Antony; Akgun, Bora; Ecklund, Karl Matthew; Geurts, Frank JM; Li, Wei; Michlin, Benjamin; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Ferbel, Thomas; Garcia-Bellido, Aran; Goldenzweig, Pablo; Han, Jiyeon; Harel, Amnon; Khukhunaishvili, Aleko; Miner, Daniel Carl; Petrillo, Gianluca; Vishnevskiy, Dmitry; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Mesropian, Christina; Arora, Sanjay; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Lath, Amitabh; Panwalkar, Shruti; Park, Michael; Patel, Rishi; Rekovic, Vladimir; Salur, Sevil; Schnetzer, Steve; Seitz, Claudia; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Rose, Keith; Spanier, Stefan; York, Andrew; Bouhali, Othmane; Eusebi, Ricardo; Flanagan, Will; Gilmore, Jason; Kamon, Teruki; Khotilovich, Vadim; Krutelyov, Vyacheslav; Montalvo, Roy; Osipenkov, Ilya; Pakhotin, Yuriy; Perloff, Alexx; Roe, Jeffrey; Rose, Anthony; Safonov, Alexei; Sakuma, Tai; Suarez, Indara; Tatarinov, Aysen; Akchurin, Nural; Cowden, Christopher; Damgov, Jordan; Dragoiu, Cosmin; Dudero, Phillip Russell; Faulkner, James; Kovitanggoon, Kittikul; Kunori, Shuichi; Lee, Sung Won; Libeiro, Terence; Volobouev, Igor; Appelt, Eric; Delannoy, Andrés G; Greene, Senta; Gurrola, Alfredo; Johns, Willard; Maguire, Charles; Mao, Yaxian; Melo, Andrew; Sharma, Monika; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Arenton, Michael Wayne; Boutle, Sarah; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Lin, Chuanzhe; Neu, Christopher; Wood, John; Gollapinni, Sowjanya; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Sturdy, Jared; Belknap, Donald; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Duric, Senka; Friis, Evan; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Lanaro, Armando; Lazaridis, Christos; Levine, Aaron; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Perry, Thomas; Pierro, Giuseppe Antonio; Polese, Giovanni; Ross, Ian; Sarangi, Tapas; Savin, Alexander; Smith, Wesley H; Woods, Nathaniel

    2014-01-01

    Event-shape variables, which are sensitive to perturbative and nonperturbative aspects of quantum chromodynamic (QCD) interactions, are studied in multijet events recorded in proton-proton collisions at $\\sqrt{s}$ = 7 TeV. Events are selected with at least one jet with transverse momentum $p_{\\rm T} > 110$ GeV and pseudorapidity |$\\eta$| $<2.4$, in a data sample corresponding to integrated luminosities of up to 5 fb$^{-1}$. The distributions of five event-shape variables in various leading jet $p_{\\rm T}$ ranges are compared to predictions from different QCD Monte Carlo event generators.

  4. Holographic QCD: Past, Present, and Future

    OpenAIRE

    Kim, Youngman; Shin, Ik Jae; Tsukioka, Takuya

    2012-01-01

    At the dawn of a new theoretical tool based on the AdS/CFT correspondence for nonperturbative aspects of quantum chromodynamics, we give an interim review on the new tool, holographic QCD, with some of its accomplishment. We try to give an A-to-Z picture of the holographic QCD, from string theory to a few selected top-down holographic QCD models with one or two physical applications in each model. We may not attempt to collect diverse results from various holographic QCD model studies.

  5. Strong-coupling constant with flavor thresholds at five loops in the anti M anti S scheme

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, B.A.; Kotikov, A.V.; Onishchenko, A.I.; Veretin, O.L. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2006-07-15

    We present in analytic form the matching conditions for the strong-coupling constant {alpha}{sub s}{sup (n{sub f})}({mu}) at the flavor thresholds to four loops in the modified minimal-subtraction scheme. Taking into account the present knowledge on the coefficient {beta}{sub 4} of the Callan-Symanzik beta function of quantum chromo-dynamics, we thus derive a five-loop formula for {alpha}{sub s}{sup (n{sub f})}({mu}) together with appropriate relationships between the asymptotic scale parameters {lambda}{sup (n{sub f})} for different numbers of flavors n{sub f}. (Orig.)

  6. QCD : the theory of strong interactions Conference MT17

    CERN Multimedia

    2001-01-01

    The theory of strong interactions,Quantum Chromodynamics (QCD), predicts that the strong interaction is transmitted by the exchange of particles called gluons. Unlike the messengers of electromagnetism photons, which are electrically neutral - gluons carry a strong charge associated with the interaction they mediate. QCD predicts that the strength of the interaction between quarks and gluons becomes weaker at higher energies. LEP has measured the evolution of the strong coupling constant up to energies of 200 GeV and has confirmed this prediction.

  7. QCD : the theory of strong interactions Exhibition LEPFest 2000

    CERN Multimedia

    2000-01-01

    The theory of strong interactions,Quantum Chromodynamics (QCD),predicts that the strong interac- tion is transmitted by the exchange of particles called glu- ons.Unlike the messengers of electromagnetism -pho- tons,which are electrically neutral -gluons carry a strong charge associated with the interaction they mediate. QCD predicts that the strength of the interaction between quarks and gluons becomes weaker at higher energies.LEP has measured the evolution of the strong coupling constant up to energies of 200 GeV and has confirmed this prediction.

  8. Vacuum stability problem in QCD

    CERN Document Server

    Kim, Youngman; Pak, D G; Park, Chanyong; Tsukioka, Takuya

    2016-01-01

    The problem of existence of a stable vacuum monopole condensation in a pure quantum chromodynamics (QCD) is revised. Our approach is based on using classical stationary non-linear wave type solutions with intrinsic mass scale parameters. Such solutions can be treated as quantum mechanical wave functions describing massive spinless states in the quantum theory. We verify whether non-linear wave type solutions can form vacuum condensates stable against quantum fluctuations within the effective action formalism. We demonstrate that there is a special class of stationary regular solutions representing a Wu-Yang monopole dressed in gluon field which provides a stable color magnetic condensate in a pure QCD.

  9. Determination of alpha_s from the QCD static energy: an update

    CERN Document Server

    Bazavov, Alexei; Tormo, Xavier Garcia i; Petreczky, Peter; Soto, Joan; Vairo, Antonio

    2014-01-01

    We present an update of our determination of the strong coupling alpha_s from the quantum chromodynamics static energy. This updated analysis includes new lattice data, at smaller lattice spacings and reaching shorter distances, the use of better suited perturbative expressions to compare with data in a wider distance range, and a comprehensive and detailed estimate of the error sources that contribute to the uncertainty of the final result. Our updated value for alpha_s at the Z-mass scale, M_Z, is alpha_s(M_Z)=0.1166^{+0.0012}_{-0.0008}, which supersedes our previous result.

  10. Need for spontaneous breakdown of chiral symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Salomone, A.; Schechter, J.; Tudron, T.

    1981-07-15

    The question of whether the chiral symmetry of the theory of strong interactions (with massless quarks) is required to be spontaneously broken is examined in the framework of a previously discussed effective Lagrangian for quantum chromodynamics. The assumption that physical masses of the theory be finite leads in a very direct way to the necessity of spontaneous breakdown. This result holds for all N/sub F/> or =2, where N/sub F/ is the number of different flavors of light quarks. The atypical cases N/sub F/ = 1,2 are discussed separately.

  11. [Studies of elementary particles and high energy phenomena: [Progress report

    International Nuclear Information System (INIS)

    The scope of work under this contract is unclassified and shall consist of experimental, theoretical, and phenomenological research on the fundamental properties of high energy subnuclear particles at the Fermi National Accelerator Laboratory, the Stanford Linear Accelerator Center, the Los Alamos National Laboratory, the SSC laboratory, and the University of Colorado with emphasis on photon beam experiments, electron-positron interactions, charmed particles, production of new vector bosons, advanced data acquisition systems, two photon physics, particle lifetimes, supergravity, supersymmetry, superstrings, quantum chromodynamics, nonequilibrium statistical mechanics, cosmology, phase transitions, lattice gauge theory, anomaly-free theories, gravity and instrumentation development. These topics are covered in this report

  12. QCD critical point: the race is on

    International Nuclear Information System (INIS)

    A critical point in the phase diagram of quantum chromodynamics (QCD), if established either theoretically or experimentally, would be as profound a discovery as the good-old gas-liquid critical point. Unlike the latter, however, first-principles-based approaches are being employed to locate it theoretically. Due to the short-lived nature of the concerned phases, novel experimental techniques are needed to search for it. The Relativistic Heavy Ion Collider (RHIC) in USA has an experimental programme to do so. This short review is an attempt to provide a glimpse of the race between the theorists and the experimentalists as well as the synergy between them. (author)

  13. Strong Gravity Approach to QCD and General Relativity

    CERN Document Server

    Akinto, O F

    2016-01-01

    A systematic study of the Weyl-type / Yang-Mills-type action possessing local conformal invariance and quadratic curvature is undertaken. The dynamical breaking of this conformal invariance / scale invariance induces general relativity (GR) as an effective long distance limit of the theory. We prove that the corresponding field equations of the theory have the linearly rising potential, which naturally possesses asymptotic freedom and color confinement properties of quantum chromodynamics (QCD). Solutions to the neutrino mass and dark energy problems come as free gifts of this formulation. This approach provides a strong gravity basis for the unification of quantum Yang-Mills theory (QYMT) with Einstein GR.

  14. Accelerating dark-matter axion searches with quantum measurement technology

    CERN Document Server

    Zheng, Huaixiu; Brierley, R T; Girvin, S M; Lehnert, K W

    2016-01-01

    The axion particle, a consequence of an elegant hypothesis that resolves the strong-CP problem of quantum chromodynamics, is a plausible origin for cosmological dark matter. In searches for axionic dark matter that detect the conversion of axions to microwave photons, the quantum noise associated with microwave vacuum fluctuations will soon limit the rate at which parameter space is searched. Here we show that this noise can be partially overcome either by squeezing the quantum vacuum using recently developed Josephson parametric devices, or by using superconducting qubits to count microwave photons.

  15. Hadron spectra, flow and correlations in PbPb collisions at the LHC: interplay between soft and hard physics

    CERN Document Server

    Lokhtin, I P; Malinina, L V; Petrushanko, S V; Rogochaya, E P; Snigirev, A M

    2012-01-01

    The started LHC heavy ion program makes it possible to probe new frontiers of the high temperature Quantum Chromodynamics. It is expected that the role of hard and semi-hard particle production processes may be significant at ultra-high energies even for bulk properties of the created matter. In this paper, the LHC data on multiplicity, hadron spectra, elliptic flow and femtoscopic correlations from PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed in the framework of the HYDJET++ model. The influence of the jet production mechanism on these observables is discussed.

  16. Active helium target: Neutron scalar polarizability extraction via Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Meg, E-mail: mmorris@mta.ca; Hornidge, David [Mount Allison University, Sackville, New Brunswick (Canada); Annand, John; Strandberg, Bruno [University of Glasgow, Scotland (United Kingdom)

    2015-12-31

    Precise measurement of the neutron scalar polarizabilities has been a lasting challenge because of the lack of a free-neutron target. Led by the University of Glasgow and the Mount Allison University groups of the A2 collaboration in Mainz, Germany, preparations have begun to test a recent theoretical model with an active helium target with the hope of determining these elusive quantities with small statistical, systematic, and model-dependent errors. Apparatus testing and background-event simulations have been carried out, with the full experiment projected to run in 2015. Once determined, these values can be applied to help understand quantum chromodynamics in the nonperturbative region.

  17. Implications of Local Chiral Symmetry Breaking

    CERN Document Server

    La, H S

    2003-01-01

    The spontaneous symmetry breaking of a local chiral symmetry to its diagonal vector symmetry naturally realizes a complete geometrical structure more general than that of Yang-Mills (YM) theory, rather similar to that of gravity. A good example is the Quantum Chromodynamics (QCD) with respect to the Chiral Color model. Also, a new anomaly-free particle content for a Chiral Color model is introduced: the Chiral Color can be realized without introducing whole new generations of quarks and leptons, but by simply enlarging each generation with new exotic fermions.

  18. Hadroproduction of massive lepton pairs and QCD

    International Nuclear Information System (INIS)

    A survey is presented of some current issues of interest in attempts to describe the production of massive lepton pairs in hadronic collisions at high energies. I concentrate on the interpretation of data in terms of the parton model and on predictions derived from quantum-chromodynamics (QCD), their reliability and their confrontation with experiment. Among topics treated are the connection with deep-inelastic lepton scattering, universality of structure functions, and the behavior of cross-sections as a function of transverse momentum

  19. Measurement of the forward $Z$ boson production cross-section in $pp$ collisions at $\\sqrt{s}$ = 7 TeV

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; d'Argent, Philippe; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Birnkraut, Alex; Bizzeti, Andrea; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casanova Mohr, Raimon; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Ruscio, Francesco; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gastaldi, Ugo; Gauld, Rhorry; Gavardi, Laura; Gazzoni, Giulio; Geraci, Angelo; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Humair, Thibaud; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Janine; Müller, Katharina; Müller, Vanessa; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Osorio Rodrigues, Bruno; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Poikela, Tuomas; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Sterpka, Christopher Francis; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Tekampe, Tobias; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Todd, Jacob; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wiedner, Dirk; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang

    2015-01-01

    where the uncertainties are due to the sample size, systematic effects, the beam energy and the luminosity. This result is in good agreement with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. The cross-section is also measured differentially as a function of kinematic variables of the $Z$ boson. Ratios of the production cross-sections of electroweak bosons are presented using updated LHCb measurements of $W$ boson production. A precise test of the Standard Model is provided by the measurement of the ratio

  20. The Determination of the Strong Coupling Constant

    Science.gov (United States)

    Dissertori, Günther

    2016-10-01

    The strong coupling constant is one of the fundamental parameters of the Standard Theory of particle physics. In this review I will briefly summarise the theoretical framework, within which the strong coupling constant is defined and how it is connected to measurable observables. Then I will give an historical overview of its experimental determinations and discuss the current status and world average value. Among the many different techniques used to determine this coupling constant in the context of quantum chromodynamics, I will focus in particular on a number of measurements carried out at the Large Electron-Positron Collider (LEP) and the Large Hadron Collider (LHC) at CERN.

  1. 11. international conference on elastic and diffractive scattering: towards high energy frontiers

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This conference is held every 2 years. Every time these conferences on elastic and diffractive scattering adapt their content to the most recent experimental and theoretical results concerning not only quantum chromodynamics (QCD) but also other fields of particle physics where diffractive physics is present. This year, besides classical themes such as: -) forward scattering, -) total cross-sections, -) real parts, and -) pomeron and odderon, the participants have addressed many other subjects such as: -) LHC physics, -) non-perturbative approaches to high-energy scattering, -) the dipole model, -) small-x evolution, -) hard diffraction in QCD, -) nuclear shadowing, -) diffractive Higgs studies, -) spin effects, -) 4-quarks and 5-quarks, or -) B-physics.

  2. Proceedings

    International Nuclear Information System (INIS)

    Invited talks presented at a two-week workshop on pion-nucleon interactions are briefly presented and a summary of the discussions that took place is added. Topics covered include quantum chromodynamics and the weak NNπ vertex, pionic effects in the weak decays of nuclei, the isobar-doorway approach to the pion-nucleus interaction, multiple scattering approaches, the phenomenology of non-elastic reactions within the isobar-doorway picture, a field theory of pion-nucleus interaction, and the quark structure of the nucleon in nuclei. (LL)

  3. Jumping Dynamics

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2013-01-01

    paradigm the physical scale and henceforth also the massive spectrum of the theory jump at the lower boundary of the conformal window. In particular we propose that a theory can suddenly jump from a Quantum Chromodynamics type spectrum, at the lower boundary of the conformal window, to a conformal one...... without particle interpretation. The jumping scenario, therefore, does not support a near-conformal dynamics of walking type. We will also discuss the impact of jumping dynamics on the construction of models of dynamical electroweak symmetry breaking....

  4. Non abelian hydrodynamics and heavy ion collisions

    Science.gov (United States)

    Calzetta, E.

    2014-01-01

    The goal of the relativistic heavy ion collisions (RHIC) program is to create a state of matter where color degrees of freedom are deconfined. The dynamics of matter in this state, in spite of the complexities of quantum chromodynamics, is largely determined by the conservation laws of energy momentum and color currents. Therefore it is possible to describe its main features in hydrodynamic terms, the very short color neutralization time notwithstanding. In this lecture we shall give a simple derivation of the hydrodynamics of a color charged fluid, by generalizing the usual derivation of hydrodynamics from kinetic theory to the non abelian case.

  5. Determination of the pole and MSbar masses of the top quark from the ttbar cross section

    OpenAIRE

    Abazov, V. M. et al. (D0 Collaboration); B. Abbott; Acharya, B. S.; M. Adams; Adams, T.; Alexeev, G.D.; Alkhazov, G.; A. Alton; Alverson, G.; Alves, G. A.; Ancu, L. S.; Aoki, M.; Arov, M.; Askew., A; Åsman, B.(Department of Physics, Stockholm University, Stockholm, Sweden The Oskar Klein Centre, Stockholm, Sweden)

    2011-01-01

    We use higher-order quantum chromodynamics calculations to extract the mass of the top quark from the ttbar cross section measured in the lepton+jets channel in ppbar collisions at sqrt(s)=1.96 TeV using 5.3 fb-1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider. The extracted top quark pole mass and MSbar mass are compared to the current Tevatron average top quark mass obtained from direct measurements.

  6. Significant change of the identified hadron compositions relevant to jet chemistry from p+p to Au+Au collisions at RHIC

    CERN Document Server

    Xu, Yichun

    2010-01-01

    The study of hadron spectra at high $p_{T}$ in p+p collisions provides a good test of perturbative quantum chromo-dynamic calculations (pQCD) and baseline for measurements of nuclear modification factors in Au+Au collisions. Using events triggered by the Barrel Electro-Magnetic Calorimeter, identified charged hadron transverse momentum ($p_T$) spectra are measured up to 15 GeV/$c$ at mid-rapidity ($\\mid y\\mid$ $$ 5.5 GeV/c) for kaon are compared with that of pion in Au + Au collisions at 200 GeV.

  7. Theoretical high energy physics

    International Nuclear Information System (INIS)

    This report discusses theoretical research in high energy physics at Columbia University. Some of the research topics discussed are: quantum chromodynamics with dynamical fermions; lattice gauge theory; scattering of neutrinos by photons; atomic physics constraints on the properties of ultralight-ultraweak gauge bosons; black holes; Chern- Simons physics; S-channel theory of superconductivity; charged boson system; gluon-gluon interactions; high energy scattering in the presence of instantons; anyon physics; causality constraints on primordial magnetic manopoles; charged black holes with scalar hair; properties of Chern-Aimona-Higgs solitons; and extended inflationary universe

  8. The Production Cross Sections of the Weak Vector Bosons in Proton Antiproton Collisions at s**(1/2) = 1.96-TeV and a Measurement of the W Boson Decay Width

    Energy Technology Data Exchange (ETDEWEB)

    Varganov, Alexei Valerievich

    2004-04-01

    The theory that describes the fundamental particle interactions is called the Standard Model, which is a gauge field theory that comprises the Glashow-Weinberg-Salam model [1, 2, 3] of the weak and electromagnetic interactions and quantum chromodynamics (QCD) [4, 5, 6], the theory of the strong interactions. The discovery of the W [7, 8] and Z [9, 10] bosons in 1983 by the UA1 and UA2 collaborations at the CERN p{bar p} collider provided a direct confirmation of the unification of the weak and electromagnetic interactions. Since then, many experiments have refined our understanding of the characteristics of the W and Z bosons.

  9. Nuclear Physics from Lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    William Detmold, Silas Beane, Konstantinos Orginos, Martin Savage

    2011-01-01

    We review recent progress toward establishing lattice Quantum Chromodynamics as a predictive calculational framework for nuclear physics. A survey of the current techniques that are used to extract low-energy hadronic scattering amplitudes and interactions is followed by a review of recent two-body and few-body calculations by the NPLQCD collaboration and others. An outline of the nuclear physics that is expected to be accomplished with Lattice QCD in the next decade, along with estimates of the required computational resources, is presented.

  10. Dynamical gluon mass in QCD processes

    Energy Technology Data Exchange (ETDEWEB)

    Ducati, M.B. Gay; Sauter, W. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Fisica. Grupo de Fenomenologia de Particulas de Altas Energias (GFPAE)

    2007-06-15

    We perform phenomenological applications of modified gluon propagators and running coupling constants in scattering processes in Quantum Chromodynamics (QCD). The modified forms of propagators and running coupling constant are obtained by non-perturbative methods. The processes investigated includes the diffractive ones - proton-proton elastic scattering, light vector meson photo-production and double vector meson production in gamma-gamma scattering - as well as the pion and kaon meson form factors. The results are compared with experimental data (if available), showing a good agreement with a gluon with dynamical mass but do not indicate the correct gluon propagator functional form. (author)

  11. Jirim kuark - mikroskopi elektron attoskala ke atas proton

    CERN Document Server

    Abdullah, Wan Ahmad Tajuddin Wan

    2008-01-01

    We review experiments colliding electrons(/positrons) on protons at high energies at HERA, focussing on the ZEUS experiment. We describe the ZEUS detector, including its data acquisition system, and look at a specific part, namely the electronic system for its calorimeter readout control, in more detail. Data analysis is described, and results pertaining the proton structure is given. It is found that the naive quark model cannot explain the results obtained at small fractional momentum, and this requires quantum chromodynamics. Also it is found that diffractive reactions, with large rapidity gaps, contribute substantially; efforts are being carried out to understand them.

  12. A compilation of data on single prompt photon production in hadron -hadron interactions

    International Nuclear Information System (INIS)

    A compilation of all the available data on Single Prompt Photon Production in Hadron-Hadron Interactions is presented, in both tabular and graphical form. Methods of interpreting these data in terms of a test of quantum chromodynamics (QCD) is also presented to indicate to the reader the scope and general status of the data. All the data in this review can be found in and retrieved from the Durham-RAL HEP Databases (HEPDATA on the RAL and CERN VM systems) together with data on a wide variety of other reactions. (author)

  13. Jets in deep-inelastic scattering at HERA

    International Nuclear Information System (INIS)

    Jet cross sections in deep-inelastic scattering over a wide region of phase space have been measured at HERA. These cross section measurements provide a thorough test of the implementation of quantum chromodynamics in next-to-leading order (NLO) calculations. They also provide the opportunity to test the consistency of the gluon distribution in the proton as extracted from (mainly) inclusive DIS measurements. Comparison of the cross sections with NLO enables accurate extractions of the strong coupling constant, αs, several of which are reported here. (author)

  14. J/Ψ production in deep inelastic electron scattering at HERA

    International Nuclear Information System (INIS)

    J/Ψ production in deep inelastic electron-proton scattering is calculated in the framework of nonrelativistic quantum chromodynamics. All the calculated differential distributions, except for one, turn out to be very sensitive to the colour octet mechanism. The analytical results disagree with previous analyses, both for the colour singlet and colour octet channels. The theoretical predictions agree reasonably well with recent data taken by the H1 Collaboration at DESY HERA, significantly better than those obtained within the colour singlet model. (author)

  15. POLYSHIFT Communications Software for the Connection Machine System CM-200

    Directory of Open Access Journals (Sweden)

    William George

    1994-01-01

    Full Text Available We describe the use and implementation of a polyshift function PSHIFT for circular shifts and end-offs shifts. Polyshift is useful in many scientific codes using regular grids, such as finite difference codes in several dimensions, and multigrid codes, molecular dynamics computations, and in lattice gauge physics computations, such as quantum chromodynamics (QCD calculations. Our implementation of the PSHIFT function on the Connection Machine systems CM-2 and CM-200 offers a speedup of up to a factor of 3–4 compared with CSHIFT when the local data motion within a node is small. The PSHIFT routine is included in the Connection Machine Scientific Software Library (CMSSL.

  16. Collider physics for the late 1980's

    Energy Technology Data Exchange (ETDEWEB)

    Hinchliffe, I.

    1987-02-27

    Topics in the Standard Model of strong and electroweak interactions and how these topics are relevant for the high energy colliders are discussed. Radiative corrections in the Glashow-Weinberg-Salam model are discussed, stressing how these corrections may be measured at LEP and the SLC. CP violation is discussed, followed by a discussion of the Higgs boson and the searches which can be carried out for it. Some features of quantum chromodynamics are discussed which are relevant to hadron colliders. Some of the problems which the Standard Model does not solve are discussed. 115 refs., 53 figs. (LEW)

  17. Collider physics for the late 1980's

    International Nuclear Information System (INIS)

    Topics in the Standard Model of strong and electroweak interactions and how these topics are relevant for the high energy colliders are discussed. Radiative corrections in the Glashow-Weinberg-Salam model are discussed, stressing how these corrections may be measured at LEP and the SLC. CP violation is discussed, followed by a discussion of the Higgs boson and the searches which can be carried out for it. Some features of quantum chromodynamics are discussed which are relevant to hadron colliders. Some of the problems which the Standard Model does not solve are discussed. 115 refs., 53 figs

  18. Can sigma models describe finite temperature chiral transitions?

    CERN Document Server

    Kocic, Aleksandar; Aleksandar KOCIC; John KOGUT

    1995-01-01

    Large-N expansions and computer simulations indicate that the universality class of the finite temperature chiral symmetry restoration transition in the 3D Gross-Neveu model is mean field theory. This is a counterexample to the standard 'sigma model' scenario which predicts the 2D Ising model universality class. We trace the breakdown of the standard scenario (dimensional reduction and universality) to the absence of canonical scalar fields in the model. We point out that our results could be generic for theories with dynamical symmetry breaking, such as Quantum Chromodynamics.

  19. Imaging dynamical chiral-symmetry breaking: pion wave function on the light front.

    Science.gov (United States)

    Chang, Lei; Cloët, I C; Cobos-Martinez, J J; Roberts, C D; Schmidt, S M; Tandy, P C

    2013-03-29

    We project onto the light front the pion's Poincaré-covariant Bethe-Salpeter wave function obtained using two different approximations to the kernels of quantum chromodynamics' Dyson-Schwinger equations. At an hadronic scale, both computed results are concave and significantly broader than the asymptotic distribution amplitude, φ(π)(asy)(x)=6x(1-x); e.g., the integral of φ(π)(x)/φ(π)(asy)(x) is 1.8 using the simplest kernel and 1.5 with the more sophisticated kernel. Independent of the kernels, the emergent phenomenon of dynamical chiral-symmetry breaking is responsible for hardening the amplitude.

  20. Regge behaviour of distribution functions and and -evolutions of gluon distribution function at low-

    Indian Academy of Sciences (India)

    U Jamil; J K Sarma

    2007-08-01

    In this paper, and -evolutions of gluon distribution function from Dokshitzer–Gribov–Lipatov–Altarelli–Parisi (DGLAP) evolution equation in leading order (LO) at low- are presented assuming the Regge behaviour of quarks and gluons at this limit. We compare our results of gluon distribution function with MRST 2001, MRST 2004 and GRV 1998 parametrizations and show the compatibility of Regge behaviour of quark and gluon distribution functions with perturbative quantum chromodynamics (PQCD) at low-. We also discuss the limitations of Taylor series expansion method used earlier to solve DGLAP evolution equations in the Regge behaviour of distribution functions.

  1. Lattice Gauge Theory and the Origin of Mass

    Energy Technology Data Exchange (ETDEWEB)

    Kronfeld, Andreas S.

    2013-08-01

    Most of the mass of everyday objects resides in atomic nuclei/ the total of the electrons' mass adds up to less than one part in a thousand. The nuclei are composed of nucleons---protons and neutrons---whose nuclear binding energy, though tremendous on a human scale, is small compared to their rest energy. The nucleons are, in turn, composites of massless gluons and nearly massless quarks. It is the energy of these confined objects, via $M=E/c^2$, that is responsible for everyday mass. This article discusses the physics of this mechanism and the role of lattice gauge theory in establishing its connection to quantum chromodynamics.

  2. Weak interactions at high energies. [Lectures, review

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, J.

    1978-08-01

    Review lectures are presented on the phenomenological implications of the modern spontaneously broken gauge theories of the weak and electromagnetic interactions, and some observations are made about which high energy experiments probe what aspects of gauge theories. Basic quantum chromodynamics phenomenology is covered including momentum dependent effective quark distributions, the transverse momentum cutoff, search for gluons as sources of hadron jets, the status and prospects for the spectroscopy of fundamental fermions and how fermions may be used to probe aspects of the weak and electromagnetic gauge theory, studies of intermediate vector bosons, and miscellaneous possibilities suggested by gauge theories from the Higgs bosons to speculations about proton decay. 187 references. (JFP)

  3. Charged pion production in fixed target Pb + Pb collisions at 158 GeV per nucleon

    OpenAIRE

    Ambrosini, G; Arsenescu, R.; Baglin, C.; Beringer, J.; C. Böhm; Borer, Kurt; Bussière, A.; B. Dittus, F.; Elsener, Konrad; Gorodetzky, P.; Guillaud, J.P.; O. Hess, P.; Kabana, S.; Klingenberg, R.; Lindén, T.

    1999-01-01

    Changes in pion production as a function of the impact parameter of the collision or the incident energy, may reveal characteristics of a possible first-order phase transition from nuclear to quark matter, as predicted by lattice quantum chromodynamics. In this paper we investigate charged pion production in Pb+Pb collisions at 158 GeV/nucleon near 0° production angle and at forward rapidity $(4.3\\leq y \\leq 6.3)$. The centrality dependence of pion production is shown in the impact parameter ...

  4. Heavy-flavour and quarkonium production in the LHC era: from proton-proton to heavy-ion collisions

    OpenAIRE

    A. Andronic; Arleo, F.; Arnaldi, R.; Beraudo, A.; Bruna, E.; Caffarri, D.; del Valle, Z. Conesa; Contreras, J. G.; T. Dahms; Dainese, A.; Djordjevic, M.(); Ferreiro, E. G.; Fujii, H.; Gossiaux, P. -B.; de Cassagnac, R. Granier

    2015-01-01

    This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark–Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addre...

  5. QCD critical point: The race is on

    Indian Academy of Sciences (India)

    Rajiv V Gavai

    2015-05-01

    A critical point in the phase diagram of quantum chromodynamics (QCD), if established either theoretically or experimentally, would be as profound a discovery as the good-old gas–liquid critical point. Unlike the latter, however, first-principles-based approaches are being employed to locate it theoretically. Due to the short-lived nature of the concerned phases, novel experimental techniques are needed to search for it. The Relativistic Heavy Ion Collider (RHIC) in USA has an experimental programme to do so. This short review is an attempt to provide a glimpse of the race between the theorists and the experimentalists as well as the synergy between them.

  6. The Transverse Momentum and Total Cross Section of $e^{+}e^{-}$ Pairs in the Z-Boson Region from $p\\overline{p}$ collisions at s**(1/2) = 1.8 TeV

    CERN Document Server

    Affolder, T; Akopian, A M; Albrow, Michael G; Amaral, P; Amendolia, S R; Amidei, D; Antos, J; Apollinari, G; Arisawa, T; Asakawa, T; Ashmanskas, W J; Atac, Muzaffer; Azzi-Bacchetta, P; Bacchetta, N; Bailey, M W; Bailey, S; De Barbaro, P; Barbaro-Galtieri, A; Barnes, Virgil E; Barnett, B A; Barone, M; Bauer, G; Bedeschi, F; Belforte, S; Bellettini, Giorgio; Bellinger, J; Benjamin, D; Bensinger, J; Beretvas, A; Bergé, J P; Berryhill, J W; Bertolucci, Sergio; Bevensee, B; Bhatti, A A; Bigongiari, C; Binkley, M; Bisello, D; Blair, R E; Blocker, C A; Bloom, K; Blusk, S R; Bocci, A; Bodek, Arie; Bokhari, W; Bölla, G; Bonushkin, Yu; Bortoletto, Daniela; Boudreau, J; Brandl, A; Van den Brink, J; Bromberg, C; Bruner, N L; Buckley-Geer, E; Budagov, Yu A; Budd, H S; Burkett, K; Busetto, G; Byon-Wagner, A; Byrum, K L; Campbell, M; Caner, A; Carithers, W C; Carlson, J; Carlsmith, D; Cassada, J A; Castro, A; Cauz, D; Cerri, A; Chang, P S; Chang, P T; Chapman, J; Chen, C; Chen, Y C; Cheng, M T; Chertok, M; Chiarelli, G; Chirikov-Zorin, I E; Chlachidze, G; Chlebana, F S; Christofek, L S; Chu, M L; Cihangir, S; Ciobanu, C I; Clark, A G; Cobal, M; Cocca, E; Connolly, A; Conway, J; Cooper, J; Cordelli, M; Guimarães da Costa, J; Costanzo, D; Cronin-Hennessy, D; Cropp, R; Culbertson, R J; Dagenhart, D; De Jongh, F; Dell'Agnello, S; Dell'Orso, Mauro; Demina, R; Demortier, L; Deninno, M M; Derwent, P F; Devlin, T; Dittmann, J R; Donati, S; Done, J; Dorigo, T; Eddy, N; Einsweiler, Kevin F; Elias, J E; Engels, E; Erdmann, W; Errede, D; Errede, S; Fan, Q; Feild, R G; Ferretti, C; Fiori, I; Flaugher, B L; Foster, G W; Franklin, M; Freeman, J; Friedman, J; Fukui, Y; Gadomski, S; Galeotti, S; Gallinaro, M; Gao, T; García-Sciveres, M; Müller, T; Munar, A; Murat, P; Murgia, S; Musy, M; Nachtman, J; Nahn, S; Nakada, H; Nakaya, T; Nakano, I; Nelson, C; Neuberger, D; Newman-Holmes, C; Ngan, C Y P; Nicolaidi, P; Niu, H; Nodulman, L; Nomerotski, A; Oh, S H; Ohmoto, T; Ohsugi, T; Oishi, R; Okusawa, T; Olsen, J; Pagliarone, C; Palmonari, F; Paoletti, R; Papadimitriou, V; Pappas, S P; Parri, A; Partos, D S; Patrick, J; Pauletta, G; Paulini, M; Perazzo, A; Pescara, L; Phillips, T J; Piacentino, G; Pitts, K T; Plunkett, R K; Pompos, A; Pondrom, L; Pope, G; Prokoshin, F; Proudfoot, J; Ptohos, F; Punzi, G; Ragan, K; Reher, D; Ribon, A; Rimondi, F; Ristori, L; Robertson, W J; Robinson, A; Rodrigo, T; Rolli, S; Rosenson, L; Roser, R M; Rossin, R; Sakumoto, W K; Saltzberg, D; Sansoni, A; Santi, L; Sato, H; Savard, P; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Scodellaro, L; Scott, A; Scribano, A; Segler, S L; Seidel, S; Seiya, Y; Semenov, A A; Semeria, F; Shah, T; Shapiro, M D; Shepard, P F; Shibayama, T; Shimojima, M; Shochet, M J; Siegrist, J L; Signorelli, G; Sill, A F; Sinervo, P K; Singh, P; Slaughter, A J; Sliwa, K; Smith, C; Snider, F D; Solodsky, A; Spalding, J; Speer, T; Sphicas, Paris; Spinella, F; Spiropulu, M; Spiegel, L; Stanco, L; Steele, J; Stefanini, A; Strologas, J; Strumia, F; Stuart, D; Sumorok, K; Suzuki, T; Takashima, R; Takikawa, K; Tanaka, M; Takano, T; Tannenbaum, B; Taylor, W; Tecchio, M; Teng, P K; Terashi, K; Tether, S; Theriot, D; Thurman-Keup, R M; Tipton, P; Tkaczyk, S M; Tollefson, K; Tollestrup, Alvin V; Toyoda, H; Trischuk, W; De Trocóniz, J F; Truitt, S; Tseng, J; Turini, N; Ukegawa, F; Valls, J; Vejcik, S; Velev, G V; Vidal, R; Vilar, R; Volobuev, I P; Vucinic, D; Wagner, R G; Wagner, R L; Wahl, J; Wallace, N B; Walsh, A M; Wang, C; Wang, C H; Wang, M J; Watanabe, T; Watts, T; Webb, R; Wenzel, H; Wester, W C; Wicklund, A B; Wicklund, E; Williams, H H; Wilson, P; Winer, B L; Winn, D; Wolbers, S; Wolinski, D; Wolinski, J; Worm, S; Wu, X; Wyss, J; Yagil, A; Yao, W; Yeh, G P; Yeh, P; Yoh, J K; Yosef, C; Yoshida, T; Yu, I; Yu, S; Zanetti, A; Zetti, F; Zucchelli, G C

    2000-01-01

    The transverse momentum and total cross section of e^+e^- pairs in the Z-boson region of 66chromodynamics perturbation theory at high transverse momentum with the gluon resummation formalism at low transverse momentum.

  7. Finite-volume effects on octet-baryon masses in covariant baryon chiral perturbation theory

    OpenAIRE

    Geng, Li-Sheng; Ren, Xiu-Lei; Martin-Camalich, J.; Weise, W.

    2011-01-01

    We study finite-volume effects on the masses of the ground-state octet baryons using covariant baryon chiral perturbation theory (ChPT) up to next-to-leading order by analyzing the latest $n_f=2+1$ lattice Quantum ChromoDynamics (LQCD) results from the NPLQCD collaboration. Contributions of virtual decuplet baryons are taken into account using the "consistent" coupling scheme. We compare our results with those obtained from heavy baryon ChPT and show that, although both approaches can describ...

  8. Exponential Data Fitting and its Applications

    CERN Document Server

    Pereyra, Victor

    2010-01-01

    Real and complex exponential data fitting is an important activity in many different areas of science and engineering, ranging from Nuclear Magnetic Resonance Spectroscopy and Lattice Quantum Chromodynamics to Electrical and Chemical Engineering, Vision and Robotics. The most commonly used norm in the approximation by linear combinations of exponentials is the l2 norm (sum of squares of residuals), in which case one obtains a nonlinear separable least squares problem. A number of different methods have been proposed through the years to solve these types of problems and new applications appear

  9. Nucleonic helicity distributions revisited with an emphasis on their evolutions and twists

    Indian Academy of Sciences (India)

    Rajen Kundu

    2014-12-01

    In this work, we uphold and extend the formalism advocated by us more than a decade ago in order to extract information on various distribution functions describing nucleonic helicity structure and calculate a complete set of splitting functions relevant for their quantum chromodynamics (QCD) evolutions using light-front Hamiltonian perturbation theory in light front gauge + = 0. Twist-two structures of the helicity distributions are self-evident in our calculation. Sum rules associated with these helicity distributions are also verified in a frame-independent way.

  10. Proceedings of the second symposium on science of hadrons under extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, Satoshi [ed.

    2000-08-01

    The second symposium on Science of Hadrons under Extreme Conditions, organized by the Research Group for Hadron Science, Advanced Science Research Center, was held at Tokai Research Establishment of JAERI on January 24 to 26, 2000. The symposium was devoted for discussions and presentations of research results in wide variety of fields such as nuclear matter, high-energy nuclear reactions, quantum chromodynamics, supernovae and nucleosynthesis to understand various aspects of hadrons under extreme conditions. The 26 of the presented papers are indexed individually. (J.P.N.)

  11. B hadron properties at CMS

    CERN Document Server

    Heredia De La Cruz, Ivan

    2016-01-01

    Precise measurements of B hadron properties are crucial to improve or constrain models based on non-perturbative quantum chromodynamics, which provide predictions of mass, lifetime, cross section, polarization, and branching ratios (among several other properties) of B hadrons. Measurements of CP violation in $B^0_s$ and properties of rare B decays also provide many opportunities to search for new physics. This article presents some B hadron property results obtained by CMS using Run~I (2011-2012) data, and prospects for the Run~II (2015-2017) data taking period.

  12. Study of the behavior of the nuclear modification factor in freeze-out state

    International Nuclear Information System (INIS)

    One of the latest trends in the advancement of experimental high-energy physics is to identify the quark gluon plasma (QGP) predicted qualitatively by quantum chromodynamics (QCD). We discuss whether nuclear transparency effect which is considered an important phenomenon, connected with dynamics of hadron-nuclear and nuclear-nuclear interactions could reflect some particular properties of the medium. FASTMC is used for Au-Au collision at RHIC energies. Critical change in the transparency is considered a signal on the appearance of new phases of strongly interacting matter and the QGP. (authors)

  13. 5th CERN - Latin-American School of High-Energy Physics

    CERN Document Server

    Spiropulu, M; CLASHEP 2009; CLASHEP2009

    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 early physics analysis of the ATLAS and CMS experiments. Also included are write-ups of short review projects performed by the student discussions groups.

  14. Quantum Chaos in Physical Systems from Super Conductors to Quarks

    CERN Document Server

    Bittner, E; Pullirsch, R; Bittner, Elmar; Markum, Harald; Pullirsch, Rainer

    2001-01-01

    This article is the written version of a talk delivered at the Bexbach Colloquium of Science 2000 and starts with an introduction into quantum chaos and its relationship to classical chaos. The Bohigas-Giannoni-Schmit conjecture is formulated and evaluated within random-matrix theory. Several examples of physical systems exhibiting quantum chaos ranging from nuclear to solid state physics are presented. The presentation concludes with recent research work on quantum chromodynamics and the quark-gluon plasma. In the case of a chemical potential the eigenvalue spectrum becomes complex and one has to deal with non-Hermitian random-matrix theory.

  15. Measurement of bottom versus charm as a function of transverse momentum with electron-hadron correlations in p + p collisions at square root of s = 200 GeV.

    Science.gov (United States)

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Aoki, K; Aphecetche, L; Armendariz, R; Aronson, S H; Asai, J; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Chang, B S; Chang, W C; Charvet, J-L; Chernichenko, S; Chiba, J; Chi, C Y; Chiu, M; Choi, I J; Choudhury, R K; Chujo, T; Chung, P; Churyn, A; Cianciolo, V; Citron, Z; Cleven, C R; Cole, B A; Comets, M P; Constantin, P; Csanád, M; Csörgo, T; Dahms, T; Dairaku, S; Das, K; David, G; Deaton, M B; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durum, A; Dutta, D; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Gustafsson, H-A; Hachiya, T; Henni, A Hadj; Haegemann, C; Haggerty, J S; Hamagaki, H; Han, R; Harada, H; Hartouni, E P; Haruna, K; Haslum, E; Hayano, R; Heffner, M; Hemmick, T K; Hester, T; He, X; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Inoue, Y; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Jacak, B V; Jia, J; Jin, J; Jinnouchi, O; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneta, M; Kang, J H; Kanou, H; Kapustinsky, J; Kawall, D; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, B I; Kim, D H; Kim, D J; Kim, E; Kim, S H; Kinney, E; Kiriluk, K; Kiss, A; Kistenev, E; Kiyomichi, A; Klay, J; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kozlov, A; Král, A; Kravitz, A; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y-S; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, D M; Lee, K B; Lee, M K; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Liebing, P; Liska, T; Litvinenko, A; Liu, H; Liu, M X; Li, X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mannel, E; Mao, Y; Masek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; Means, N; Meredith, B; Miake, Y; Mikes, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, M; Mitchell, J T; Mitrovski, M; Mohanty, A K; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Niita, T; Norman, B E; Nouicer, R; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Okada, H; Okada, K; Oka, M; Omiwade, O O; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roach, D; Roche, G; Rolnick, S D; Romana, A; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ruzicka, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Sakata, H; Samsonov, V; Sato, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Semenov, V; Seto, R; Sharma, D; Shein, I; Shevel, A; Shibata, T-A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skutnik, S; Slunecka, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarján, P; Themann, H; Thomas, T L; Togawa, M; Toia, A; Tojo, J; Tomásek, L; Tomita, Y; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Veicht, A; Velkovska, J; Vertesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, Y; Wei, F; Wessels, J; White, S N; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zhou, S; Zimányi, J; Zolin, L

    2009-08-21

    The momentum distribution of electrons from semileptonic decays of charm and bottom quarks for midrapidity |y|e(+/-)K(-/+)X (K unidentified) reconstruction. It is found that the yield of electrons from bottom becomes significant above 4 GeV/c in pT. A fixed-order-plus-next-to-leading-log perturbative quantum chromodynamics calculation agrees with the data within the theoretical and experimental uncertainties. The extracted total bottom production cross section at this energy is sigma(bb)=3.2(-1.1)(+1.2)(stat)(-1.3)(+1.4)(syst)mub. PMID:19792719

  16. Nuclear-modification factor for open-heavy-flavor production at forward rapidity in Cu plus Cu collisions at root s(NN)=200 GeV

    OpenAIRE

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y; Al-Bataineh, H.; Alexander, J.; Aoki, K.; Aphecetche, L.; Armendariz, R.; Aronson, S. H.; Asai, J.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.

    2012-01-01

    Background: Heavy-flavor production in p + p collisions is a good test of perturbative-quantum-chromodynamics (pQCD) calculations. Modification of heavy-flavor production in heavy-ion collisions relative to binary-collision scaling from p + p results, quantified with the nuclear-modification factor (R-AA), provides information on both cold-and hot-nuclear-matter effects. Midrapidity heavy-flavor R-AA measurements at the Relativistic Heavy Ion Collider have challenged parton-energy-loss models...

  17. Direct-Photon Production in p+p Collisions at sqrt(s)=200 GeV at Midrapidity

    OpenAIRE

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y; Al-Bataineh, H.; Alexander, J.; Aoki, K.; Aphecetche, L.; Asai, J.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.

    2012-01-01

    The differential cross section for the production of direct photons in p+p collisions at sqrt(s)=200 GeV at midrapidity was measured in the PHENIX detector at the Relativistic Heavy Ion Collider. Inclusive-direct photons were measured in the transverse-momentum range from 5.5--25 GeV/c, extending the range beyond previous measurements. Event structure was studied with an isolation criterion. Next-to-leading-order perturbative-quantum-chromodynamics calculations give a good description of the ...

  18. Structure functions in the chiral bag model

    Energy Technology Data Exchange (ETDEWEB)

    Sanjose, V.; Vento, V.

    1989-07-13

    We calculate the structure functions of an isoscalar nuclear target for the deep inelastic scattering by leptons in an extended version of the chiral bag model which incorporates the qanti q structure of the pions in the cloud. Bjorken scaling and Regge behavior are satisfied. The model calculation reproduces the low-x behavior of the data but fails to explain the medium- to large-x behavior. Evolution of the quark structure functions seem inevitable to attempt a connection between the low-energy models and the high-energy behavior of quantum chromodynamics. (orig.).

  19. The influence of chiral chemical potential, parallel electric and magnetic fields on the critical temperature of QCD

    CERN Document Server

    Ruggieri, M; Peng, G X

    2016-01-01

    We study the influence of external electric, $E$, and magnetic, $B$, fields parallel to each other, and of a chiral chemical potential, $\\mu_5$, on the chiral phase transition of Quantum Chromodynamics. Our theoretical framework is a Nambu-Jona-Lasinio model with a contact interaction. Within this model we compute the critical temperature of chiral symmetry restoration, $T_c$, as a function of the chiral chemical potential and field strengths. We find that the fields inhibit and $\\mu_5$ enhances chiral symmetry breaking, in agreement with previous studies.

  20. The Phase Diagram of QC2D from Functional Methods

    CERN Document Server

    Khan, Naseemuddin; Rennecke, Fabian; Scherer, Michael M

    2015-01-01

    We study the phase diagram of two-color Quantum Chromodynamics at finite temperature and chemical potential. This is done within an effective low-energy description in terms of quarks, mesons and diquarks. Quantum, thermal and density fluctuations are taken into account with the functional renormalisation group approach. In particular, we establish the phenomenon of pre-condensation, affecting the location of the phase boundary to Bose-Einstein condensation. We also discuss the Silver Blaze property in the context of the functional renormalisation group.

  1. Chiral Soliton Lattice and Charged Pion Condensation in Strong Magnetic Fields

    CERN Document Server

    Brauner, Tomas

    2016-01-01

    The Chiral Soliton Lattice (CSL) is a state with a periodic array of topological solitons that spontaneously breaks parity and translational symmetries. Such a state is known to appear in chiral magnets. We show that CSL also appears as a ground state of quantum chromodynamics at nonzero chemical potential in a magnetic field. By analyzing the fluctuations of the CSL, we furthermore demonstrate that in strong but achievable magnetic fields, charged pions undergo Bose-Einstein condensation. Our results, based on a systematic low-energy effective theory, are model-independent and fully analytic.

  2. Simple QED- and QCD-like models at finite density

    Science.gov (United States)

    Pawlowski, Jan M.; Stamatescu, Ion-Olimpiu; Zielinski, Christian

    2015-07-01

    In this paper we discuss one-dimensional models reproducing some features of quantum electrodynamics and quantum chromodynamics at nonzero density and temperature. Since a severe sign problem makes a numerical treatment of QED and QCD at high density difficult, such models help to explore various effects peculiar to the full theory. Studying them gives insights into the large density behavior of the Polyakov loop by taking both bosonic and fermionic degrees of freedom into account, although in one dimension only the implementation of a global gauge symmetry is possible. For these models we evaluate the respective partition functions and discuss several observables as well as the Silver Blaze phenomenon.

  3. Improved Polyakov-loop potential for effective models from functional calculations

    OpenAIRE

    Haas, Lisa M.; Stiele, Rainer; Braun, Jens; Pawlowski, Jan M.; Schaffner-Bielich, Jürgen

    2013-01-01

    We investigate the quark backreaction on the Polyakov loop and its impact on the thermodynamics of quantum chromodynamics. The dynamics of the gluons generating the Polyakov-loop potential is altered by the presence of dynamical quarks. However, this backreaction of the quarks has not yet been taken into account in Polyakov-loop extended model studies. In the present work, we show within a 2+1 flavour Polyakov-quark-meson model that a quark-improved Polyakov-loop potential leads to a smoother...

  4. Multiflavor Correlation Functions in non-Abelian Gauge Theories at Finite Density in two dimensions

    CERN Document Server

    Christiansen, H R; Christiansen, Hugo R.; Schaposnik, Fidel A.

    1996-01-01

    We compute vacuum expectation values of products of fermion bilinears for two-dimensional Quantum Chromodynamics at finite flavored fermion densities. We introduce the chemical potential as an external charge distribution within the path-integral approach and carefully analyse the contribution of different topological sectors to fermion correlators. We show the existence of chiral condensates exhibiting an oscillatory inhomogeneous behavior as a function of a chemical potential matrix. This result is exact and goes in the same direction as the behavior found in QCD$_4$ within the large $N$ approximation.

  5. QCD Physics (CMS)

    CERN Document Server

    Cerci, Salim

    2016-01-01

    Jets which are the signatures of quarks and gluons in the detector can be described by Quantum Chromodynamics (QCD) in terms of parton-parton scattering. Jets are abundantly produced at the LHC's high energy scales. Measurements of inclusive jets, dijets and multijets can be used to test perturbative QCD predictions and to constrain parton distribution functions (PDF), as well as to measure the strong coupling constant $\\alpha_{S}$. The measurements use the samples of proton-proton collisions collected with the CMS detector at the LHC at various center-of-mass energies of 7, 8 and 13 TeV.

  6. Inclusive Jet measurements at 2.76, 7, 8 and 13 TeV from CMS

    CERN Document Server

    Gunnellini, Paolo

    2016-01-01

    Measurements of double-differential inclusive jet cross sections as a function of jet transverse momentum pT and absolute jet rapidity are presented for different collision energies. The analysis are based on proton-proton collisions collected by the CMS experiment. Jets are defined through the anti-kT clustering algorithm for different cone sizes. It is observed that predictions of perturbative quantum chromodynamics at next-to-leading order precision, complemented with nonperturbative corrections, are able to reproduce the measured data for the considered energies with a very good level of agreement. Parton-shower contributions are crucial for the description of jets, reconstructed with smaller cone sizes.

  7. Cornell Potential Parameters for S-wave Heavy Quarkonia

    CERN Document Server

    Chung, Hee Sok; Kang, Daekyoung

    2008-01-01

    We compute derived quantities for various values of the model parameter of the Cornell potential model for the S-wave heavy quarkonia with radial quantum numbers n=1, 2, and 3. Our results can be used to determine leading and relative-order-v^2 nonrelativistic quantum chromodynamics matrix elements for S-wave charmonia and bottomonia such as psi(2S), eta_c(2S), and Upsilon(nS) for n=1, 2, and 3. These matrix elements will be essential ingredients for resumming relativistic corrections to processes involving those S-wave heavy quarkonium states.

  8. Searching for the rules that govern hadron construction.

    Science.gov (United States)

    Shepherd, Matthew R; Dudek, Jozef J; Mitchell, Ryan E

    2016-06-23

    Just as quantum electrodynamics describes how electrons are bound in atoms by the electromagnetic force, mediated by the exchange of photons, quantum chromodynamics (QCD) describes how quarks are bound inside hadrons by the strong force, mediated by the exchange of gluons. QCD seems to allow hadrons constructed from increasingly many quarks to exist, just as atoms with increasing numbers of electrons exist, yet such complex constructions seemed, until recently, not to be present in nature. Here we describe advances in the spectroscopy of mesons that are refining our understanding of the rules for predicting hadron structure from QCD. PMID:27337337

  9. Electroweak production of top-quark pairs in e+e- annihilation at NNLO in QCD: The vector current contributions

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jun [Southern Methodist Univ., Dallas, TX (United States); Zhu, Hua Xing [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2014-12-17

    We report on a calculation of the vector current contributions to the electroweak production of top quark pairs in e+e annihilation at next-to-next-to-leading order in quantum chromodynamics. Our setup is fully differential and can be used to calculate any infrared-safe observable. The real emission contributions are handled by a next-to-next-to-leading order generalization of the phase-space slicing method. As a result, we demonstrate the power of our technique by considering its application to various inclusive and exclusive observables.

  10. Max-Planck-Institute for Nuclear Physics. Annual report 1987

    International Nuclear Information System (INIS)

    This annual report contains short communications and extended abstracts about the work performed at the named institute together with a list of publications and talks. The work concerns technical developments on accelerators and ion sources, developments of detectors and experimental setups, electronics, data processing, target developments, giant resonances, nuclear spectroscopy, nuclear reaction mechanisms, atomic physics, medium- and high-energy physics, statistical models of nuclei and nuclear reactions, nuclear reactions at high energies, many-particle theory, quantum chromodynamics, meteorites, comets, interstellar dust, planetary atmospheres, cosmic radiation, molecular collisions in the earth atmosphere, nuclear geology and geochemistry, as well as archaeology. See hints under the relevant topics. (HSI)

  11. Topology in dynamical lattice QCD simulations

    International Nuclear Information System (INIS)

    Lattice simulations of Quantum Chromodynamics (QCD), the quantum field theory which describes the interaction between quarks and gluons, have reached a point were contact to experimental data can be made. The underlying mechanisms, like chiral symmetry breaking or the confinement of quarks, are however still not understood. This thesis focuses on topological structures in the QCD vacuum. Those are not only mathematically interesting but also closely related to chiral symmetry and confinement. We consider methods to identify these objects in lattice QCD simulations. Based on this, we explore the structures resulting from different discretizations and investigate the effect of a very strong electromagnetic field on the QCD vacuum.

  12. 1995 European school of high-energy physics. Proceedings

    International Nuclear Information System (INIS)

    The European School of High-Energy Physics is intended to give young experimentalists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lectures on Field Theory, the Standard Model, Physics beyond the Standard Model, Quantum Chromodynamics and Deep Inelastic Scattering, B-Physics and CP Violation, Neutrino Oscillations, Dark Matter, Experimental Techniques, as well as reports on Heavy Ions and Collider Physics and an account of particle physics at JINR. Two local subjects are also treated: Conditions for Science in Russia, and Search for Heavy Elements. (orig.)

  13. Search for contact interactions using the inclusive jet p(T) spectrum in pp collisions at root s=7 TeV

    OpenAIRE

    Chatrchyan S.; Khachatryan V.; Sirunyan A.M.; Tumasyan A.; Adam W.; Aguilo E.; Bergauer T.; Dragicevic M.; Ero J.; Fabjan C.

    2013-01-01

    Artículo escrito por muchos autores, sólo se referencian el primero, los autores que firman como Universidad Autónoma de Madrid y el grupo de colaboración en el caso de que aparezca en el artículo Results are reported of a search for a deviation in the jet production cross section from the prediction of perturbative quantum chromodynamics at next-to-leading order. The search is conducted using a 7 TeV proton-proton data sample corresponding to an integrated luminosity of 5.0 fb-1, collecte...

  14. TMD Parton Distributions based on Three-Body Decay Functions in NLL Order of QCD

    CERN Document Server

    Tanaka, Hidekazu

    2014-01-01

    Three-body decay functions in space-like parton branches are implemented to evaluate transverse-momentum-dependent (TMD) parton distribution functions in the next-to-leading logarithmic (NLL) order of quantum chromodynamics (QCD). Interference contributions due to the next-to-leading order contribution are taken into account for the evaluation of the transverse momenta in initial state parton radiations. Some properties of the decay functions are also examined. As an example, we compare our results with an algorithm proposed in Ref.1), in which a transverse momentum distributions are evaluated at the last step of parton evolutions.

  15. Charm-Quark Production in Deep-Inelastic Neutrino Scattering at Next-to-Next-to-Leading Order in QCD.

    Science.gov (United States)

    Berger, Edmond L; Gao, Jun; Li, Chong Sheng; Liu, Ze Long; Zhu, Hua Xing

    2016-05-27

    We present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. We compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. Our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon. PMID:27284650

  16. Measurement of the inclusive jet cross section using the midpoint algorithm in Run II at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Group, Robert Craig; /Florida U.

    2006-12-01

    A measurement is presented of the inclusive jet cross section using the Midpoint jet clustering algorithm in five different rapidity regions. This is the first analysis which measures the inclusive jet cross section using the Midpoint algorithm in the forward region of the detector. The measurement is based on more than 1 fb{sup -1} of integrated luminosity of Run II data taken by the CDF experiment at the Fermi National Accelerator Laboratory. The results are consistent with the predictions of perturbative quantum chromodynamics.

  17. Evidence for the color-octet mechanism from CERN LEP2 gamma gamma --> J/psi + X Data.

    Science.gov (United States)

    Klasen, Michael; Kniehl, Bernd A; Mihaila, Luminiţa N; Steinhauser, Matthias

    2002-07-15

    We present theoretical predictions for the transverse-momentum distribution of J/psi mesons promptly produced in gammagamma collisions within the factorization formalism of nonrelativistic quantum chromodynamics, including the contributions from both direct and resolved photons, and we perform a conservative error analysis. The fraction of J/psi mesons from decays of bottom-flavored hadrons is estimated to be negligibly small. New data taken by the DELPHI Collaboration at LEP2 nicely confirm these predictions, while they disfavor those obtained within the traditional color-singlet model.

  18. Non abelian hydrodynamics and heavy ion collisions

    CERN Document Server

    Calzetta, Esteban

    2013-01-01

    The goal of the relativistic heavy ion collisions (RHIC) program is to create a state of matter where color degrees of freedom are deconfined. The dynamics of matter in this state, in spite of the complexities of quantum chromodynamics, is largely determined by the conservation laws of energy momentum and color currents. Therefore it is possible to describe its main features in hydrodynamic terms, the very short color neutralization time notwithstanding. In this lecture we shall give a simple derivation of the hydrodynamics of a color charged fluid, by generalizing the usual derivation of hydrodynamics from kinetic theory to the non abelian case.

  19. At the frontier of particle physics handbook of QCD : Festschrift Boris Ioffe

    CERN Document Server

    2000-01-01

    This book consists of reviews covering all aspects of quantum chromodynamics as we know it today. The articles have been written by recognized experts in this field, in honor of the 75th birthday of Professor Boris Ioffe. Combining features of a handbook and a textbook, this is the most comprehensive source of information on the present status of QCD. It is intended for students as well as physicists - both theorists and experimentalists.Each review is self-contained and pedagogically structured, providing the general formulation of the problem, telling where it stands with respect to other is

  20. Towards a dynamical preon model

    International Nuclear Information System (INIS)

    We discuss further the recently proposed ''primordial'' quantum chromodynamics, where a massive Fermi-Bose couple of two colour triplets delta and chi of spin 1/2 and 0, respectively, and of equal charge - 1/3 interacts with a colour octet of massless vector gluons. The ''preons'' delta and chi form bound states #betta#sub(e) = delta chi-bar, e=delta(chichi)sub(P) (colour singlets) and u=delta-bar chi-bar, d=delta-bar (chichi)sub(P) (colour triplets). Other preon bound states also exist and are briefly reviewed. (author)

  1. National Computational Infrastructure for Lattice Gauge Theory: Final Report

    International Nuclear Information System (INIS)

    This is the final report of Department of Energy SciDAC Grant ''National Computational Infrastructure for Lattice Gauge Theory''. It describes the software developed under this grant, which enables the effective use of a wide variety of supercomputers for the study of lattice quantum chromodynamics (lattice QCD). It also describes the research on and development of commodity clusters optimized for the study of QCD. Finally, it provides some high lights of research enabled by the infrastructure created under this grant, as well as a full list of the papers resulting from research that made use of this infrastructure

  2. Proceedings of the 2011 CERN - Latin American School of High-Energy Physics

    International Nuclear Information System (INIS)

    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, flavour physics and CP-violation, physics beyond the Standard Model, neutrino physics, particle cosmology, ultrahigh-energy cosmic rays and heavy-ion physics, as well as a presentation of recent results form the Large Hadron Collider (LHC) and short introduction to the principles of particle physics instrumentation

  3. NLO QCD Corrections for $\\chi_{cJ}$ Inclusive Production at $B$ Factories

    CERN Document Server

    Chen, Long-Bin; Qiao, Cong-Feng

    2014-01-01

    The next-to-leading order (NLO) quantum chromodynamics (QCD) corrections for $\\chi_{cJ}(^3P_J^{[1]},^3S_1^{[8]})$, the P-wave charmoniums inclusive production at $B$ factories are calculated utilizing the non-relativistic QCD (NRQCD) factorization formalism. Large NLO corrections are found, especially for $^3P_0^{[1]}$ and $^3S_1^{[8]}$ configurations. Numerical evaluation indicates that the total cross sections of $\\chi_{cJ}+c+\\bar{c}$ processes are about $1\\sim100$fb, which are accessible in the super-B experiment.

  4. Proceedings of the 2011 CERN - Latin American School of High-Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Grojean, C.; Mulders, M.; Spiropulu (eds.)

    2011-07-01

    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, flavour physics and CP-violation, physics beyond the Standard Model, neutrino physics, particle cosmology, ultrahigh-energy cosmic rays and heavy-ion physics, as well as a presentation of recent results form the Large Hadron Collider (LHC) and short introduction to the principles of particle physics instrumentation.

  5. QCD resummation for hadronic final states

    Science.gov (United States)

    Luisoni, Gionata; Marzani, Simone

    2015-10-01

    We review the basic concepts of all-order calculations in quantum chromodynamics (QCD) and their application to collider phenomenology. We start by discussing the factorization properties of QCD amplitudes and cross-sections in the soft and collinear limits and their resulting all-order exponentiation. We then discuss several applications of this formalism to observables which are of great interest at particle colliders. In this context, we describe the all-order resummation of event-shape distributions, as well as observables that probe the internal structure of hadronic jets.

  6. Resummation in QCD

    CERN Document Server

    Luisoni, Gionata

    2015-01-01

    We review the basic concepts of all-order calculations in Quantum Chromodynamics (QCD) and their application to collider phenomenology. We start by discussing the factorization properties of QCD amplitudes and cross-sections in the soft and collinear limits and their resulting all-order exponentiation. We then discuss several applications of this formalism to observables which are of great interest at particle colliders. In this context, we describe the all-order resummation of event-shape distributions, as well as observables that probe the internal structure of hadronic jets.

  7. Non-perturbative effective QCD Hamiltonian

    International Nuclear Information System (INIS)

    A non-relativistic approximation to quantum chromodynamics is used and nonperturbative properties of the vacuum are parameterized by the gluon condensate. We calculate non-perturbative contributions in mesons by extending the basis to also include singlet states formed by octet quark-antiquark states coupled to the background fields. We thereby calculate masses and wave functions of pseudoscalar heavy mesons. Non-perturbative effects are shown to be more important in higher excited states. The background gauge formalism used preserves gauge invariance. (author)

  8. The Electron-Ion Collider Science Case

    CERN Document Server

    Milner, Richard G

    2014-01-01

    For the first time, physicists are in the position to precisely study a fully relativistic quantum field theory: Quantum ChromoDynamics (QCD). QCD is a central element of the Standard Model and provides the theoretical framework for understanding the strong interaction. This demands a powerful new electron microscope to probe the virtual particles of QCD. Ab initio calculations using lattice gauge theory on the world's most powerful supercomputers are essential for comparison with the data. The new accelerator and computing techniques demand aggressive development of challenging, innovative technologies.

  9. Light nuclei from chiral EFT interactions

    International Nuclear Information System (INIS)

    Recent developments in nuclear theory allow us to make a connection between quantum chromodynamics (QCD) and low-energy nuclear physics. First, chiral effective field theory (XEFT) provides a natural hierarchy to define two-nucleon (NN), three-nucleon (NNN), and even four-nucleon interactions. Second, ab-initio methods have been developed capable to test these interactions for light nuclei. In this contribution, we discuss ab-initio no-core shell-model (NCSM) calculations for s-shell and p-shell nuclei with NN and NNN interactions derived within XEFT. Presented at the 20th Few-Body Conference, Pisa, Italy, 10-14 September 2007. (author)

  10. Light nuclei from chiral EFT interactions

    OpenAIRE

    Navratil, P.; Gueorguiev, V. G.; Vary, J. P.; Ormand, W. E.; Nogga, A.; Quaglioni, S.

    2008-01-01

    Recent developments in nuclear theory allow us to make a connection between quantum chromodynamics (QCD) and low-energy nuclear physics. First, chiral effective field theory (chi EFT) provides a natural hierarchy to define two-nucleon (NN), three-nucleon (NNN), and even four-nucleon interactions. Second, ab-initio methods have been developed capable to test these interactions for light nuclei. In this contribution, we discuss ab-initio no-core shell-model (NCSM) calculations for s-shell and p...

  11. Fits of weak annihilation and hard spectator scattering corrections in B u,d \\wideoverrightarrow VV decays

    Science.gov (United States)

    Chang, Qin; Li, Xiao-Nan; Sun, Jun-Feng; Yang, Yue-Ling

    2016-10-01

    In this paper, the contributions of weak annihilation and hard spectator scattering in B\\to ρ {K}* , {K}* {\\bar{K}}* , φ {K}* , ρ ρ and φ φ decays are investigated within the framework of quantum chromodynamics factorization. Using the experimental data available, we perform {χ }2 analyses of end-point parameters in four cases based on the topology-dependent and polarization-dependent parameterization schemes. The fitted results indicate that: (i) in the topology-dependent scheme, the relation ({ρ }Ai,{φ }Ai)\

  12. The first lap in QCD

    International Nuclear Information System (INIS)

    The idea that quantum chromodynamics is Nature's choice for the theory of quark interactions and that desirable phenomena, such as quark confinement, are consequences of it are considered. The lecture is presented under the headings: (1) Why do we believe that quarks have colour. (2) A rapid summary of the parton model in deep inelastic scattering. (3) Non Abelian theories: the vertices. (4) Hyperfine splitting of hadrons: more evidence for colour. (5) Renormalisation. (6) Alpha(Q2). (7) The renormalisation group equations. (8) QCD, the renormalisation group equation and deep inelastic data. (9) Higher order corrections in QCD. (U.K.)

  13. Hadron and photon production at large transverse momentum and the dynamics of QCD jets. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1978-10-01

    The phenomenology of hadron and photon reactions at short distances is discussed in terms of perturbative quantum chromodynamics. In addition to large P/sub T/ hadron reactions, predictions are reviewed for jet production in two photon collisions, the relation of photon and gluon jet production, hadronic production and color separation, upsilon decay into hadrons and photons, leading particle distributions in low P/sub T/ hadron collisions, discriminants of quark and gluon jets, and the effects of coherence on gluon distributions in hadrons. A number of new experimental tests of QCD are discussed.

  14. Light-cone quantized QCD and novel hadron phenomenology

    International Nuclear Information System (INIS)

    The authors reviews progress made in solving gauge theories such as collinear quantum chromodynamics using light-cone Hamiltonian methods. He also shows how the light-cone Fock expansion for hadron wavefunctions can be used to compute operator matrix elements such as decay amplitudes, form factors, distribution amplitudes, and structure functions, and how it provides a tool for exploring novel features of QCD. The author also reviews commensurate scale relations, leading-twist identities which relate physical observables to each other, thus eliminating renormalization scale and scheme ambiguities in perturbative QCD predictions

  15. Implementation of Scientific Computing Applications on the Cell Broadband Engine

    Directory of Open Access Journals (Sweden)

    Guochun Shi

    2009-01-01

    Full Text Available The Cell Broadband Engine architecture is a revolutionary processor architecture well suited for many scientific codes. This paper reports on an effort to implement several traditional high-performance scientific computing applications on the Cell Broadband Engine processor, including molecular dynamics, quantum chromodynamics and quantum chemistry codes. The paper discusses data and code restructuring strategies necessary to adapt the applications to the intrinsic properties of the Cell processor and demonstrates performance improvements achieved on the Cell architecture. It concludes with the lessons learned and provides practical recommendations on optimization techniques that are believed to be most appropriate.

  16. Approximation of the pth Roots of a Matrix by Using Trapezoid Rule

    Directory of Open Access Journals (Sweden)

    Amir Sadeghi

    2012-01-01

    Full Text Available The computation of the roots of positive definite matrices arises in nuclear magnetic resonance, control theory, lattice quantum chromo-dynamics (QCD, and several other areas of applications. The Cauchy integral theorem which arises in complex analysis can be used for computing f(A, in particular the roots of A, where A is a square matrix. The Cauchy integral can be approximated by using the trapezoid rule. In this paper, we aim to give a brief overview of the computation of roots of positive definite matrices by employing integral representation. Some numerical experiments are given to illustrate the theoretical results.

  17. Conjugate gradient solvers on Intel Xeon Phi and NVIDIA GPUs

    CERN Document Server

    Kaczmarek, O; Steinbrecher, P; Wagner, M

    2014-01-01

    Lattice Quantum Chromodynamics simulations typically spend most of the runtime in inversions of the Fermion Matrix. This part is therefore frequently optimized for various HPC architectures. Here we compare the performance of the Intel Xeon Phi to current Kepler-based NVIDIA Tesla GPUs running a conjugate gradient solver. By exposing more parallelism to the accelerator through inverting multiple vectors at the same time, we obtain a performance greater than 300 GFlop/s on both architectures. This more than doubles the performance of the inversions. We also give a short overview of the Knights Corner architecture, discuss some details of the implementation and the effort required to obtain the achieved performance.

  18. Lattice QCD computations: Recent progress with modern Krylov subspace methods

    Energy Technology Data Exchange (ETDEWEB)

    Frommer, A. [Bergische Universitaet GH Wuppertal (Germany)

    1996-12-31

    Quantum chromodynamics (QCD) is the fundamental theory of the strong interaction of matter. In order to compare the theory with results from experimental physics, the theory has to be reformulated as a discrete problem of lattice gauge theory using stochastic simulations. The computational challenge consists in solving several hundreds of very large linear systems with several right hand sides. A considerable part of the world`s supercomputer time is spent in such QCD calculations. This paper presents results on solving systems for the Wilson fermions. Recent progress is reviewed on algorithms obtained in cooperation with partners from theoretical physics.

  19. Improved methods for the study of hadronic physics from lattice QCD

    International Nuclear Information System (INIS)

    The solution of quantum chromodynamics (QCD) on a lattice provides a first-principles method for understanding QCD in the low-energy regime, and is thus an essential tool for nuclear physics. The generation of gauge configurations, the starting point for lattice calculations, requires the most powerful leadership-class computers available. However, to fully exploit such leadership-class computing requires increasingly sophisticated methods for obtaining physics observables from the underlying gauge ensembles. In this paper, we describe a variety of recent methods that have been used to advance our understanding of the spectrum and structure of hadrons through lattice QCD. (paper)

  20. Proceedings of the second symposium on science of hadrons under extreme conditions

    International Nuclear Information System (INIS)

    The second symposium on Science of Hadrons under Extreme Conditions, organized by the Research Group for Hadron Science, Advanced Science Research Center, was held at Tokai Research Establishment of JAERI on January 24 to 26, 2000. The symposium was devoted for discussions and presentations of research results in wide variety of fields such as nuclear matter, high-energy nuclear reactions, quantum chromodynamics, supernovae and nucleosynthesis to understand various aspects of hadrons under extreme conditions. The 26 of the presented papers are indexed individually. (J.P.N.)

  1. Spin dependence of associated production of a prompt photon and a charm quark at next-to-leading order in QCD

    International Nuclear Information System (INIS)

    A second order, O(α2s), calculation in perturbative quantum chromodynamics is presented of the longitudinal spin dependence of the cross section for the two particle inclusive reaction p + p -> γ + c + Χ for large values of the transverse momentum of the prompt photon and charm quark. Differential distributions are provided for the spin-averaged cross section and for the two-spin longitudinal polarization asymmetry ALL at the energy of the Brookhaven Relativistic Heavy Ion Collider. An assessment is given of the prospects for determination of the spin dependence of the charm quark density

  2. On the chiral phase transition in the linear sigma model

    International Nuclear Information System (INIS)

    The Cornwall- Jackiw-Tomboulis (CJT) effective action for composite operators at finite temperature is used to investigate the chiral phase transition within the framework of the linear sigma model as the low-energy effective model of quantum chromodynamics (QCD). A new renormalization prescription for the CJT effective action in the Hartree-Fock (HF) approximation is proposed. A numerical study, which incorporates both thermal and quantum effect, shows that in this approximation the phase transition is of first order. However, taking into account the higher-loop diagrams contribution the order of phase transition is unchanged. (author)

  3. Pion transition form factor through Dyson-Schwinger equations

    CERN Document Server

    Raya, Khépani

    2016-01-01

    In the framework of Dyson-Schwinger equations (DSE), we compute the $\\gamma^*\\gamma\\to\\pi^0$ transition form factor, $G(Q^2)$. For the first time, in a continuum approach to quantun chromodynamics (QCD), it was possible to compute $G(Q^2)$ on the whole domain of space-like momenta. Our result agrees with CELLO, CLEO and Belle collaborations and, with the well-known asymptotic QCD limit, $2f_\\pi$. Our analysis unifies this prediction with that of the pion's valence-quark parton distribution amplitude (PDA) and elastic electromagnetic form factor.

  4. Open and hidden charm production at RHIC and LHC

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, R.

    2005-10-12

    We discuss aspects of open and hidden charm production in hadron-nucleus collisions at RHIC and LHC energies. We first discuss the extraction of the total charm cross section in lower energy collisions and how it compares to next-to-leading order quantum chromodynamics calculations. We then describe calculations of the transverse momentum distributions and their agreement with the shape of the measured STAR transverse momentum distributions. We next explain how shadowing and moderate nuclear absorption can explain the PHENIX J/{psi} dAu/pp ratios.

  5. Collisional energy loss above the critical temperature in QCD

    CERN Document Server

    Lin, Shu; Skokov, Vladimir V

    2013-01-01

    We compute the collisional energy loss for a heavy quark above the critical temperature in Quantum ChromoDynamics (QCD). We work in the semi Quark-Gluon Plasma, which assumes that this region is dominated by the non-trivial holonomy of the thermal Wilson line. Relative to the result to leading order in perturbation theory, at a fixed value of the coupling constant we generically we find that collisional energy loss is suppressed by powers of the Polyakov loop, l < 1. For small values of the loop, this suppression is linear for the scattering off of light quarks, and quadratic for the scattering off of gluons, or for Compton scattering.

  6. Collisional energy loss above the critical temperature in QCD

    Science.gov (United States)

    Lin, Shu; Pisarski, Robert D.; Skokov, Vladimir V.

    2014-03-01

    We compute the collisional energy loss for a heavy quark above the critical temperature in Quantum ChromoDynamics (QCD). We work in the semi Quark-Gluon Plasma, which assumes that this region is dominated by the non-trivial holonomy of the thermal Wilson line. Relative to the result of leading order in perturbation theory, at a fixed value of the coupling constant we generically find that collisional energy loss is suppressed by powers of the Polyakov loop, lsuppression is linear when the heavy quark scatters off of light quarks, and quadratic when the heavy quark scatters off of gluons, or for Compton scattering.

  7. Measurement of the W Plus N Inclusive Jets Cross-Section at CDF Run II

    Energy Technology Data Exchange (ETDEWEB)

    Stentz, Dale James [Northwestern Univ., Evanston, IL (United States)

    2012-01-01

    In this thesis we present the study of the production of the W boson in association with hadronic jets at the Collider Detector at Fermilab (CDF). Along with the electroweak properties the W boson, we examine jet kinematic variables with the aim of studying predictions of perturbative quantum chromodynamics. We derive several di erential crosssections as a function of the inclusive jet multiplicity and the transverse momenta of each jet. In this analysis, we are using 2.8 fb-1 of data and consider both the electron and muon lepton nal states for the W boson decay.

  8. QCD for Collider Physics

    CERN Document Server

    Skands, Peter

    2012-01-01

    These lectures are directed at a level suitable for graduate students in experimental and theoretical High Energy Physics. They are intended to give an introduction to the theory and phenomenology of quantum chromodynamics (QCD) as it is used in collider physics applications. The aim is to bring the reader to a level where informed decisions can be made concerning different approaches and their uncertainties. The material is divided into four main areas: 1) fundamentals, 2) perturbative QCD, 3) soft QCD, and 4) Monte Carlo event generators.

  9. Signals for transversity and transverse-momentum-dependent quark distribution functions studied at the HERMES experiment

    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.

  10. Jets and QCD

    Energy Technology Data Exchange (ETDEWEB)

    Ali, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kramer, G. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

    2010-12-15

    The observation of quark and gluon jets has played a crucial role in establishing Quantum Chromodynamics [QCD] as the theory of the strong interactions within the Standard Model of particle physics. The jets, narrowly collimated bundles of hadrons, reflect configurations of quarks and gluons at short distances. Thus, by analysing energy and angular distributions of the jets experimentally, the properties of the basic constituents of matter and the strong forces acting between them can be explored. In this review we summarise the properties of quark and gluon jets and the impact of their observation on Quantum Chromodynamics, primarily the discovery of the gluons as the carriers of the strong force. Focusing on these basic points, jets in e{sup +}e{sup -} collisions will be in the foreground of the discussion. In addition we will delineate the role of jets as tools for exploring other particle aspects in ep and pp/p anti p collisions - quark and gluon densities in protons, measurements of the QCD coupling, fundamental 2-2 quark/gluon scattering processes, but also the impact of jet decays of top quarks, and W{sup {+-}},Z bosons on the electroweak sector. The presentation to a large extent is formulated in a non-technical language with the intent to recall the significant steps historically and convey the significance of this field also to communities beyond high energy physics. (orig.)

  11. Deep inelastic phenomena

    International Nuclear Information System (INIS)

    Nucleon structure as seen in the context of deep inelastic scattering is discussed. The lectures begin with consideration of the quark-parton model. The model forms the basis of understanding lepton-nucleon inelastic scattering. As improved data in lepton-nucleon scattering at high energies became available, the quark-parton model failed to explain some crucial features of these data. At approximately the same time a candidate theory of strong interactions based on a SU(3) gauge theory of color was being discussed in the literature, and new ideas on the explanation of inelastic scattering data became popular. A new theory of strong interactions, now called quantum chromodynamics provides a new framework for understanding the data, with a much stronger theoretical foundation, and seems to explain well the features of the data. The lectures conclude with a look at some recent experiments which provide new data at very high energies. These lectures are concerned primarily with charged lepton inelastic scattering and to a lesser extent with neutrino results. Furthermore, due to time and space limitations, topics such as final state hadron studies, and multi-muon production are omitted here. The lectures concentrate on the more central issues: the quark-parton model and concepts of scaling, scale breaking and the ideas of quantum chromodynamics, the Q2 dependence of structure function, moments, and the important parameter R

  12. Study of the nature of the confinement in the GlueX experiment

    Energy Technology Data Exchange (ETDEWEB)

    Somov, S. [Moscow Engineering Physics Institute; Berdnikov, Vladmir [Moscow Engineering Physics Institute; Tolstukhin, Ivan [Moscow Engineering Physics Institute; Somov, Alexander S. [Jefferson Lab, Newport News, VA

    2015-11-01

    Confinement is a fundamental property of quantum chromodynamics (QCD) associated with the unique role of the gluonic field responsible for binding quarks in hadrons. Understanding the role of gluons in the confinement of quarks is one of the most tantalizing topics in modern particle physics to be explored. The new experiment GlueX has been recently constructed at Jefferson Lab. The experiment was designed to search for hybrid mesons with exotic quantum numbers using a beam of linearly polarized photons incident on a liquid hydrogen target. The spectrum of these states and their mass splitting from normal mesons may yield information on confinement. In addition, these observations in combination with detailed chromodynamics calculations such as on the Lattice can provide important tests for our understanding of the role of gluons. The production of exotic mesons is expected to be enhanced in p interactions, where the experimental data is very limited. We present the description of the GlueX detector, beam line, and first results of the commissioning with photon beam.

  13. Contribution to the study of the inclusive reactions with high transverse momentum charged particles in the pp interactions (√s = 53 GeV) at the CERN ISR

    International Nuclear Information System (INIS)

    Two theoretical models, model of the partons and chromodynamic approach, are compared with the experimental values of the inclusive invariant cross section of the reaction in the angular areas between 80 and 250. The analysis of these data in terms of partonic model with distribution of the transverse momentum of quarks in the initial hadrons is not satisfactory, if the aim is describe at the same time the existing data with a very large psub(T) (psub(T)> 12. GeVc) (theta* = 900) and remains quite as vulnerable when a charge differential is introduced to account for the nature of the triggering particle. A more elaborate description of the elementary scattering processes based on the introduction of the vectorial gluons from the Lagrangian formulation of the Q.C.D. seems adequate enough to reproduce the low psub(T) and high psub(T) data, not only at 900 but also in the 80 0 angular area. It also retains the transverse moments dependence of the constituants in the initial hadrons, formulated in the partonic model. In conclusion, the Quantum Chromodynamic, which so far has not entered into conflit with any phenomenology of existing strong interactions, appears to provide a theoretical framework appropriate to the description of the hadronic interactions with a great transverse momentum

  14. Measurement of higher cumulants of net-charge multiplicity distributions in Au$+$Au collisions at $\\sqrt{s_{_{NN}}}=7.7-200$ GeV

    CERN Document Server

    Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Al-Ta'ani, H; Angerami, A; Aoki, K; Apadula, N; Aramaki, Y; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Bannier, B; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Baumgart, S; Bazilevsky, A; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Black, D; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Castera, P; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choi, S; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Connors, M; Constantin, P; Cronin, N; Crossette, N; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; Daugherity, M S; David, G; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Ding, L; Dion, A; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gainey, K; Gal, C; Garg, P; Garishvili, A; Garishvili, I; Giordano, F; Glenn, A; Gong, H; Gong, X; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guo, L; Gustafsson, H -Å; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Hanks, J; Hartouni, E P; Hashimoto, K; Haslum, E; Hayano, R; Hayashi, S; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ide, J; Iinuma, H; Ikeda, Y; Imai, K; Imazu, Y; Imrek, J; Inaba, M; Iordanova, A; Isenhower, D; Ishihara, M; Isinhue, A; Isobe, T; Issah, M; Isupov, A; Ivanishchev, D; Jacak, B V; Javani, M; Jia, J; Jiang, X; Jin, J; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khandai, P K; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E -J; Kim, H J; Kim, K -B; Kim, S H; Kim, Y -J; Kim, Y K; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Klatsky, J; Kleinjan, D; Kline, P; Kochenda, L; Komatsu, Y; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Krizek, F; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, B; Lee, D M; Lee, J; Lee, K; Lee, K B; Lee, K S; Lee, S H; Lee, S R; Leitch, M J; Leite, M A L; Leitgab, M; Leitner, E; Lenzi, B; Lewis, B; Li, X; Liebing, P; Lim, S H; Levy, L A Linden; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Luechtenborg, R; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Maruyama, T; Masui, H; Masumoto, S; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Midori, J; Mignerey, A C; Mikeš, P; Miki, K; Milov, A; Mishra, D K; Mishra, M; Mitchell, J T; Miyachi, Y; Miyasaka, S; Mohanty, A K; Mohapatra, S; Moon, H J; Morino, Y; Morreale, A; Morrison, D P; Moskowitz, M; Motschwiller, S; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagae, T; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nattrass, C; Nederlof, A; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nouicer, R; Novitzky, N; Nukariya, A; Nyanin, A S; Obayashi, H; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J; Park, S; Park, S K; Park, W J; Pate, S F; Patel, L; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Peresedov, V; Peressounko, D Yu; Petti, R; Pinkenburg, C; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Riveli, N; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ružička, P; Ryu, M S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Sako, H; Samsonov, V; Sano, M; Sano, S; Sarsour, M; Sato, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Sen, A; Seto, R; Sett, P; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skolnik, M; Slunečka, M; Solano, S; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Sparks, N A; Stankus, P W; Steinberg, P; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Sukhanov, A; Sun, J; Sziklai, J; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Tennant, E; Themann, H; Thomas, T L; Todoroki, T; Togawa, M; Toia, A; Tomášek, L; Tomášek, M; Torii, H; Towell, R S; Tserruya, I; Tsuchimoto, Y; Tsuji, T; Vale, C; Valle, H; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Voas, B; Vossen, A; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; Whitaker, S; White, S N; Winter, D; Wolin, S; Wood, J P; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhang, C; Zhou, S; Zolin, L

    2015-01-01

    We report the measurement of cumulants ($C_n, n=1\\ldots4$) of the net-charge distributions measured within pseudorapidity ($|\\eta|<0.35$) in Au$+$Au collisions at $\\sqrt{s_{_{NN}}}=7.7-200$ GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider. The ratios of cumulants (e.g. $C_1/C_2$, $C_3/C_1$) of the net-charge distributions, which can be related to volume independent susceptibility ratios, are studied as a function of centrality and energy. These quantities are important to understand the quantum-chromodynamics phase diagram and possible existence of a critical end point. The measured values are very well described by expectation from negative binomial distributions. We do not observe any nonmonotonic behavior in the ratios of the cumulants as a function of collision energy. The measured values of $C_1/C_2 = \\mu/\\sigma^2$ and $C_3/C_1 = S\\sigma^3/\\mu$ can be directly compared to lattice quantum-chromodynamics calculations and thus allow extraction of both the chemical freeze-out temperat...

  15. Measurement of higher cumulants of net-charge multiplicity distributions in Au +Au collisions at √{sN N}=7.7 -200 GeV

    Science.gov (United States)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Bataineh, H.; Alexander, J.; Al-Ta'Ani, H.; Angerami, A.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Baublis, V.; Baumann, C.; Baumgart, S.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bickley, A. A.; Black, D.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Castera, P.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Constantin, P.; Cronin, N.; Crossette, N.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; Daugherity, M. S.; David, G.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Ding, L.; Dion, A.; Do, J. H.; Donadelli, M.; D'Orazio, L.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Dutta, D.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Gainey, K.; Gal, C.; Garg, P.; Garishvili, A.; Garishvili, I.; Giordano, F.; Glenn, A.; Gong, H.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Guo, L.; Gustafsson, H.-Å.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Hanks, J.; Hartouni, E. P.; Hashimoto, K.; Haslum, E.; Hayano, R.; Hayashi, S.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hohlmann, M.; Hollis, R. S.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Hornback, D.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imazu, Y.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Ishihara, M.; Isinhue, A.; Isobe, T.; Issah, M.; Isupov, A.; Ivanishchev, D.; Jacak, B. V.; Javani, M.; Jia, J.; Jiang, X.; Jin, J.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Key, J. A.; Khandai, P. K.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, H. J.; Kim, K.-B.; Kim, S. H.; Kim, Y.-J.; Kim, Y. K.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Klatsky, J.; Kleinjan, D.; Kline, P.; Kochenda, L.; Komatsu, Y.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kotov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Krizek, F.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, B.; Lee, D. M.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Leitner, E.; Lenzi, B.; Lewis, B.; Li, X.; Liebing, P.; Lim, S. H.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Malakhov, A.; Malik, M. D.; Manion, A.; Manko, V. I.; Mannel, E.; Mao, Y.; Maruyama, T.; Masui, H.; Masumoto, S.; Matathias, F.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Means, N.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Midori, J.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Milov, A.; Mishra, D. K.; Mishra, M.; Mitchell, J. T.; Miyachi, Y.; Miyasaka, S.; Mohanty, A. K.; Mohapatra, S.; Moon, H. J.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moskowitz, M.; Motschwiller, S.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Nederlof, A.; Netrakanti, P. K.; Newby, J.; Nguyen, M.; Nihashi, M.; Niida, T.; Nouicer, R.; Novitzky, N.; Nukariya, A.; Nyanin, A. S.; Obayashi, H.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Oka, M.; Okada, K.; Onuki, Y.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, J.; Park, S.; Park, S. K.; Park, W. J.; Pate, S. F.; Patel, L.; Pei, H.; Peng, J.-C.; Pereira, H.; Perepelitsa, D. V.; Peresedov, V.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Reygers, K.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Riveli, N.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Ryu, M. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakashita, K.; Sako, H.; Samsonov, V.; Sano, M.; Sano, S.; Sarsour, M.; Sato, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Sen, A.; Seto, R.; Sett, P.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skolnik, M.; Slunečka, M.; Solano, S.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Stankus, P. W.; Steinberg, P.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Tennant, E.; Themann, H.; Thomas, T. L.; Todoroki, T.; Togawa, M.; Toia, A.; Tomášek, L.; Tomášek, M.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Tsuji, T.; Vale, C.; Valle, H.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Voas, B.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; Wessels, J.; Whitaker, S.; White, S. N.; Winter, D.; Wolin, S.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xia, B.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zhang, C.; Zhou, S.; Zolin, L.; Phenix Collaboration

    2016-01-01

    We report the measurement of cumulants (Cn,n =1 ,...,4 ) of the net-charge distributions measured within pseudorapidity (|η |<0.35 ) in Au +Au collisions at √{sNN}=7.7 -200 GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider. The ratios of cumulants (e.g., C1/C2 , C3/C1 ) of the net-charge distributions, which can be related to volume independent susceptibility ratios, are studied as a function of centrality and energy. These quantities are important to understand the quantum-chromodynamics phase diagram and possible existence of a critical end point. The measured values are very well described by expectation from negative binomial distributions. We do not observe any nonmonotonic behavior in the ratios of the cumulants as a function of collision energy. The measured values of C1/C2 and C3/C1 can be directly compared to lattice quantum-chromodynamics calculations and thus allow extraction of both the chemical freeze-out temperature and the baryon chemical potential at each center-of-mass energy. The extracted baryon chemical potentials are in excellent agreement with a thermal-statistical analysis model.

  16. Jets and QCD

    International Nuclear Information System (INIS)

    The observation of quark and gluon jets has played a crucial role in establishing Quantum Chromodynamics [QCD] as the theory of the strong interactions within the Standard Model of particle physics. The jets, narrowly collimated bundles of hadrons, reflect configurations of quarks and gluons at short distances. Thus, by analysing energy and angular distributions of the jets experimentally, the properties of the basic constituents of matter and the strong forces acting between them can be explored. In this review we summarise the properties of quark and gluon jets and the impact of their observation on Quantum Chromodynamics, primarily the discovery of the gluons as the carriers of the strong force. Focusing on these basic points, jets in e+e- collisions will be in the foreground of the discussion. In addition we will delineate the role of jets as tools for exploring other particle aspects in ep and pp/p anti p collisions - quark and gluon densities in protons, measurements of the QCD coupling, fundamental 2-2 quark/gluon scattering processes, but also the impact of jet decays of top quarks, and W±,Z bosons on the electroweak sector. The presentation to a large extent is formulated in a non-technical language with the intent to recall the significant steps historically and convey the significance of this field also to communities beyond high energy physics. (orig.)

  17. Jets and QCD

    CERN Document Server

    Ali, Ahmed

    2010-01-01

    The observation of quark and gluon jets has played a crucial role in establishing Quantum Chromodynamics [QCD] as the theory of the strong interactions within the Standard Model of particle physics. The jets, narrowly collimated bundles of hadrons, reflect configurations of quarks and gluons at short distances. Thus, by analysing energy and angular distributions of the jets experimentally, the properties of the basic constituents of matter and the strong forces acting between them can be explored. In this review we summarise the properties of quark and gluon jets and the impact of their observation on Quantum Chromodynamics, primarily the discovery of the gluons as the carriers of the strong force. Focusing on these basic points, jets in $e^+ e^-$ collisions will be in the foreground of the discussion. In addition we will delineate the role of jets as tools for exploring other particle aspects in $ep$ and $pp/p\\bar{p}$ collisions - quark and gluon densities in protons, measurements of the QCD coupling, fundam...

  18. Nuclear reactions from lattice QCD

    Science.gov (United States)

    Briceño, Raúl A.; Davoudi, Zohreh; Luu, Thomas C.

    2015-02-01

    One of the overarching goals of nuclear physics is to rigorously compute properties of hadronic systems directly from the fundamental theory of strong interactions, quantum chromodynamics (QCD). In particular, the hope is to perform reliable calculations of nuclear reactions which will impact our understanding of environments that occur during big bang nucleosynthesis, the evolution of stars and supernovae, and within nuclear reactors and high energy/density facilities. Such calculations, being truly ab initio, would include all two-nucleon and three-nucleon (and higher) interactions in a consistent manner. Currently, lattice quantum chromodynamics (LQCD) provides the only reliable option for performing calculations of some of the low-energy hadronic observables. With the aim of bridging the gap between LQCD and nuclear many-body physics, the Institute for Nuclear Theory held a workshop on Nuclear Reactions from LQCD on March 2013. In this review article, we report on the topics discussed in this workshop and the path planned to move forward in the upcoming years.

  19. Studies of high-transverse momentum jet substructure and top quarks produced in 1.96 TeV proton-antiproton collisions

    CERN Document Server

    Aaltonen, Timo Antero; Amerio, Silvia; Amidei, Dante E; Anastassov, Anton Iankov; Annovi, Alberto; Antos, Jaroslav; Apollinari, Giorgio; Appel, Jeffrey A; Arisawa, Tetsuo; Artikov, Akram Muzafarovich; Asaadi, Jonathan A; Ashmanskas, William Joseph; Auerbach, Benjamin; Aurisano, Adam J; Azfar, Farrukh A; Badgett, William Farris; Bae, Taegil; Barbaro-Galtieri, Angela; Barnes, Virgil E; Barnett, Bruce Arnold; Barria, Patrizia; Bartos, Pavol; Bauce, Matteo; Bedeschi, Franco; Behari, Satyajit; Bellettini, Giorgio; Bellinger, James Nugent; Benjamin, Douglas P; Beretvas, Andrew F; Bhatti, Anwar Ahmad; Bland, Karen Renee; Blumenfeld, Barry J; Bocci, Andrea; Bodek, Arie; Bortoletto, Daniela; Boudreau, Joseph Francis; Boveia, Antonio; Brigliadori, Luca; Bromberg, Carl Michael; Brucken, Erik; Budagov, Ioulian A; Budd, Howard Scott; Burkett, Kevin Alan; Busetto, Giovanni; Bussey, Peter John; Butti, Pierfrancesco; Buzatu, Adrian; Calamba, Aristotle; Camarda, Stefano; Campanelli, Mario; Canelli, Florencia; Carls, Benjamin; Carlsmith, Duncan L; Carosi, Roberto; Carrillo Moreno, Salvador; Casal Larana, Bruno; Casarsa, Massimo; Castro, Andrea; Catastini, Pierluigi; Cauz, Diego; Cavaliere, Viviana; Cavalli-Sforza, Matteo; Cerri, Alessandro; Cerrito, Lucio; Chen, Yen-Chu; Chertok, Maxwell Benjamin; Chiarelli, Giorgio; Chlachidze, Gouram; Cho, Kihyeon; Chokheli, Davit; Clark, Allan Geoffrey; Clarke, Christopher Joseph; Convery, Mary Elizabeth; Conway, John Stephen; Corbo, Matteo; Cordelli, Marco; Cox, Charles Alexander; Cox, David Jeremy; Cremonesi, Matteo; Cruz Alonso, Daniel; Cuevas Maestro, Javier; Culbertson, Raymond Lloyd; D'Ascenzo, Nicola; Datta, Mousumi; de Barbaro, Pawel; Demortier, Luc M; Deninno, Maria Maddalena; D'Errico, Maria; Devoto, Francesco; Di Canto, Angelo; Di Ruzza, Benedetto; Dittmann, Jay Richard; Donati, Simone; D'Onofrio, Monica; Dorigo, Mirco; Driutti, Anna; Duchovni, Ehud; Ebina, Koji; Edgar, Ryan Christopher; Elagin, Andrey L; Erbacher, Robin D; Errede, Steven Michael; Esham, Benjamin; Farrington, Sinead Marie; Fernández Ramos, Juan Pablo; Field, Richard D; Flanagan, Gene U; Forrest, Robert David; Franklin, Melissa EB; Freeman, John Christian; Frisch, Henry J; Funakoshi, Yujiro; Galloni, Camilla; Garfinkel, Arthur F; Garosi, Paola; Gerberich, Heather Kay; Gerchtein, Elena A; Giagu, Stefano; Giakoumopoulou, Viktoria Athina; Gibson, Karen Ruth; Ginsburg, Camille Marie; Giokaris, Nikos D; Giromini, Paolo; Glagolev, Vladimir; Glenzinski, Douglas Andrew; Gold, Michael S; Goldin, Daniel; Golossanov, Alexander; Gomez, Gervasio; Gomez-Ceballos, Guillelmo; Goncharov, Maxim T; González López, Oscar; Gorelov, Igor V; Goshaw, Alfred T; Goulianos, Konstantin A; Gramellini, Elena; Grinstein, Sebastian; Grosso-Pilcher, Carla; Group, Robert Craig; Guimaraes da Costa, Joao; Hahn, Stephen R; Han, Ji-Yeon; Happacher, Fabio; Hara, Kazuhiko; Hare, Matthew Frederick; Harr, Robert Francis; Harrington-Taber, Timothy; Hatakeyama, Kenichi; Hays, Christopher Paul; Heinrich, Joel G; Herndon, Matthew Fairbanks; Hocker, James Andrew; Hong, Ziqing; Hopkins, Walter Howard; Hou, Suen Ray; Hughes, Richard Edward; Husemann, Ulrich; Hussein, Mohammad; Huston, Joey Walter; Introzzi, Gianluca; Iori, Maurizio; Ivanov, Andrew Gennadievich; James, Eric B; Jang, Dongwook; Jayatilaka, Bodhitha Anjalike; Jeon, Eun-Ju; Jindariani, Sergo Robert; Jones, Matthew T; Joo, Kyung Kwang; Jun, Soon Yung; Junk, Thomas R; Kambeitz, Manuel; Kamon, Teruki; Karchin, Paul Edmund; Kasmi, Azeddine; Kato, Yukihiro; Ketchum, Wesley Robert; Keung, Justin Kien; Kilminster, Benjamin John; Kim, DongHee; Kim, Hyunsoo; Kim, Jieun; Kim, Min Jeong; Kim, Shin-Hong; Kim, Soo Bong; Kim, Young-Jin; Kim, Young-Kee; Kimura, Naoki; Kirby, Michael H; Knoepfel, Kyle James; Kondo, Kunitaka; Kong, Dae Jung; Konigsberg, Jacobo; Kotwal, Ashutosh Vijay; Kreps, Michal; Kroll, IJoseph; Kruse, Mark Charles; Kuhr, Thomas; Kurata, Masakazu; Laasanen, Alvin Toivo; Lammel, Stephan; Lancaster, Mark; Lannon, Kevin Patrick; Latino, Giuseppe; Lee, Hyun Su; Lee, Jaison; Leo, Sabato; Leone, Sandra; Lewis, Jonathan D; Limosani, Antonio; Lipeles, Elliot David; Lister, Alison; Liu, Hao; Liu, Qiuguang; Liu, Tiehui Ted; Lockwitz, Sarah E; Loginov, Andrey Borisovich; Lucchesi, Donatella; Lucà, Alessandra; Lueck, Jan; Lujan, Paul Joseph; Lukens, Patrick Thomas; Lungu, Gheorghe; Lys, Jeremy E; Lysak, Roman; Madrak, Robyn Leigh; Maestro, Paolo; Malik, Sarah Alam; Manca, Giulia; Manousakis-Katsikakis, Arkadios; Marchese, Luigi Marchese; Margaroli, Fabrizio; Marino, Christopher Phillip; Martínez-Perez, Mario; Matera, Keith; Mattson, Mark Edward; Mazzacane, Anna; Mazzanti, Paolo; McNulty, Ronan; Mehta, Andrew; Mehtala, Petteri; Mesropian, Christina; Miao, Ting; Mietlicki, David John; Mitra, Ankush; Miyake, Hideki; Moed, Shulamit; Moggi, Niccolo; Moon, Chang-Seong; Moore, Ronald Scott; Morello, Michael Joseph; Mukherjee, Aseet; Muller, Thomas; Murat, Pavel A; Mussini, Manuel; Nachtman, Jane Marie; Nagai, Yoshikazu; Naganoma, Junji; Nakano, Itsuo; Napier, Austin; Nett, Jason Michael; Neu, Christopher Carl; Nigmanov, Turgun S; Nodulman, Lawrence J; Noh, Seoyoung; Norniella Francisco, Olga; Oakes, Louise Beth; Oh, Seog Hwan; Oh, Young-do; Oksuzian, Iuri Artur; Okusawa, Toru; Orava, Risto Olavi; Ortolan, Lorenzo; Pagliarone, Carmine Elvezio; Palencia, Jose Enrique; Palni, Prabhakar; Papadimitriou, Vaia; Parker, William Chesluk; Pauletta, Giovanni; Paulini, Manfred; Paus, Christoph Maria Ernst; Perez, Gilad; Phillips, Thomas J; Piacentino, Giovanni M; Pianori, Elisabetta; Pilot, Justin Robert; Pitts, Kevin T; Plager, Charles; Pondrom, Lee G; Poprocki, Stephen; Potamianos, Karolos Jozef; Pranko, Aliaksandr Pavlovich; Prokoshin, Fedor; Ptohos, Fotios K; Punzi, Giovanni; Redondo Fernández, Ignacio; Renton, Peter B; Rescigno, Marco; Rimondi, Franco; Ristori, Luciano; Robson, Aidan; Rodriguez, Tatiana Isabel; Rolli, Simona; Ronzani, Manfredi; Roser, Robert Martin; Rosner, Jonathan L; Ruffini, Fabrizio; Ruiz Jimeno, Alberto; Russ, James S; Rusu, Vadim Liviu; Sakumoto, Willis Kazuo; Sakurai, Yuki; Santi, Lorenzo; Sato, Koji; Saveliev, Valeri; Savoy-Navarro, Aurore; Schlabach, Philip; Schmidt, Eugene E; Schwarz, Thomas A; Scodellaro, Luca; Scuri, Fabrizio; Seidel, Sally C; Seiya, Yoshihiro; Semenov, Alexei; Sforza, Federico; Shalhout, Shalhout Zaki; Shears, Tara G; Shepard, Paul F; Shimojima, Makoto; Shochet, Melvyn J; Shreyber-Tecker, Irina; Simonenko, Alexander V; Sinervo, Pekka; Sliwa, Krzysztof Jan; Smith, John Rodgers; Snider, Frederick Douglas; Song, Hao; Sorin, Maria Veronica; St Denis, Richard Dante; Stancari, Michelle Dawn; Stentz, Dale James; Strologas, John; Sudo, Yuji; Sukhanov, Alexander I; Suslov, Igor M; Takemasa, Ken-ichi; Takeuchi, Yuji; Tang, Jian; Tecchio, Monica; Teng, Ping-Kun; Thom, Julia; Thomson, Evelyn Jean; Thukral, Vaikunth; Toback, David A; Tokar, Stanislav; Tollefson, Kirsten Anne; Tomura, Tomonobu; Tonelli, Diego; Torre, Stefano; Torretta, Donatella; Totaro, Pierluigi; Trovato, Marco; Ukegawa, Fumihiko; Uozumi, Satoru; Velev, Gueorgui; Vellidis, Konstantinos; Vernieri, Caterina; Vidal Marono, Miguel; Vilar Cortabitarte, Rocio; Vizán Garcia, Jesus Manuel; Vogel, Marcelo; Volpi, Guido; Vázquez-Valencia, Elsa Fabiola; Wagner, Peter; Wallny, Rainer S; Wang, Song-Ming; Waters, David S; Wester, William Carl; Whiteson, Daniel O; Wicklund, Arthur Barry; Wilbur, Scott; Williams, Hugh H; Wilson, Jonathan Samuel; Wilson, Peter James; Winer, Brian L; Wittich, Peter; Wolbers, Stephen A; Wolfe, Homer; Wright, Thomas Roland; Wu, Xin; Wu, Zhenbin; Yamamoto, Kazuhiro; Yamato, Daisuke; Yang, Tingjun; Yang, Un-Ki; Yang, Yu Chul; Yao, Wei-Ming; Yeh, Gong Ping; Yi, Kai; Yoh, John; Yorita, Kohei; Yoshida, Takuo; Yu, Geum Bong; Yu, Intae; Zanetti, Anna Maria; Zeng, Yu; Zhou, Chen; Zucchelli, Stefano

    2015-01-01

    Results of a study of the substructure of the highest transverse momentum (pT) jets observed by the CDF collaboration are presented. Events containing at least one jet with pT > 400 GeV/c in a sample corresponding to an integrated luminosity of 5.95 inverse fb, collected in 1.96 TeV proton-antiproton collisions at the Fermilab Tevatron collider, are selected. A study of the jet mass, angularity, and planar-flow distributions is presented, and the measurements are compared with predictions of perturbative quantum chromodynamics. A search for boosted top-quark production is also described, leading to a 95% confidence level upper limit of 38 fb on the production cross section of top quarks with pT > 400 GeV/c.

  20. Measurements of W Charge Asymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Holzbauer, J. L. [Mississippi U.

    2015-10-06

    We discuss W boson and lepton charge asymmetry measurements from W decays in the electron channel, which were made using 9.7 fb$^{-1}$ of RunII data collected by the D0 detector at the Fermilab Tevatron Collider. The electron charge asymmetry is presented as a function of pseudo-rapidity out to |$\\eta$| $\\le$ 3.2, in five symmetric and asymmetric kinematic bins of electron transverse momentum and the missing transverse energy of the event. We also give the W charge asymmetry as a function of W boson rapidity. The asymmetries are compared with next-to-leading order perturbative quantum chromodynamics calculations. These charge asymmetry measurements will allow more accurate determinations of the proton parton distribution functions and are the most precise to date.

  1. Identified particle production and freeze-out properties in heavy-ion collisions at RHIC Beam Energy Scan program

    CERN Document Server

    ,

    2014-01-01

    The first phase of Beam Energy Scan (BES) program at the Relativistic Heavy-Ion Collider (RHIC) was started in the year 2010 with the aim to study the several aspects of the quantum chromodynamics (QCD) phase diagram. The Solenoidal Tracker At RHIC (STAR) detector has taken data at $\\sqrt{s_{NN}} = $ 7.7, 11.5, 19.6, 27, and 39 GeV in Au+Au collisions in the years 2010 and 2011 as part of the BES programme. For these beam energies, we present the results on the particle yields, average transverse mass and particle ratios for identified particles in mid-rapidity ($|y|$ < 0.1). The measured particle ratios have been used to study the chemical freeze-out dynamics within the framework of a statistical model.

  2. A primer for chiral perturbation theory

    CERN Document Server

    Scherer, Stefan

    2012-01-01

    Chiral Perturbation Theory, as effective field theory, is a commonly accepted and well established working tool, approximating quantum chromodynamics at energies well below typical hadron masses. This volume, based on a number of lectures and supplemented with additional material, provides a pedagogical introduction for graduate students and newcomers entering the field from related areas of nuclear and particle physics. Starting with the the Lagrangian of the strong interactions and general symmetry principles, the basic concepts of Chiral Perturbation Theory in the mesonic and baryonic sectors are developed. The application of these concepts is then illustrated with a number of examples. A large number of exercises (81, with complete solutions) are included to familiarize the reader with helpful calculational techniques.

  3. Measurement Of The Center-of-mass Energy Dependence Of Isolated Direct Photon Production In Proton-antiproton Collisions

    CERN Document Server

    Partos, D S

    2001-01-01

    We present a measurement of the s dependence of isolated prompt photon production in hadronic collisions. Prompt photon samples from 1.8 TeV and 0.63 TeV pp¯ collisions were recorded with the Collider Detector at Fermilab. Two independent background subtraction methods, shower shape and conversion rates, were calibrated and used to calculate the photon cross sections. The shapes of the measured cross sections as a function of photon transverse momentum were not adequately predicted by current calculations of perturbative Quantum Chromodynamics (QCD). One possible explanation for the disagreement between data and theory, an incorrect parameterization of the proton's parton distribution function, is excluded by a comparison of the cross sections as a function of photon xT, the fraction of the proton's momentum carried by the photon.

  4. Effective Field Theory for Lattice Nuclei

    Science.gov (United States)

    Barnea, N.; Contessi, L.; Gazit, D.; Pederiva, F.; van Kolck, U.

    2015-02-01

    We show how nuclear effective field theory (EFT) and ab initio nuclear-structure methods can turn input from lattice quantum chromodynamics (LQCD) into predictions for the properties of nuclei. We argue that pionless EFT is the appropriate theory to describe the light nuclei obtained in LQCD simulations carried out at pion masses heavier than the physical pion mass. We solve the EFT using the effective-interaction hyperspherical harmonics and auxiliary-field diffusion Monte Carlo methods. Fitting the three leading-order EFT parameters to the deuteron, dineutron, and triton LQCD energies at mπ≈800 MeV , we reproduce the corresponding alpha-particle binding and predict the binding energies of mass-5 and mass-6 ground states.

  5. Effective Field Theory for Lattice Nuclei

    CERN Document Server

    Barnea, N; Gazit, D; Pederiva, F; van Kolck, U

    2013-01-01

    We show how nuclear effective field theory (EFT) and ab initio nuclear-structure methods can turn input from lattice quantum chromodynamics (LQCD) into predictions for the properties of nuclei. We argue that pionless EFT is the appropriate theory to describe the light nuclei obtained in recent LQCD simulations carried out at pion masses much heavier than the physical pion mass. We solve the EFT using the effective-interaction hyperspherical harmonics and auxiliary-field diffusion Monte Carlo methods. Fitting the three leading-order EFT parameters to the deuteron, dineutron and triton LQCD energies at $m_{\\pi}\\approx 800$ MeV, we reproduce the corresponding alpha-particle binding and predict the binding energies of mass-5 and 6 ground states.

  6. Dark matter, Mach's ether and the QCD vacuum

    CERN Document Server

    Cohen-Tannoudji, Gilles

    2015-01-01

    Here is proposed the idea of linking the dark matter issue, (considered as a major problem of contemporary research in physics) with two other open theoretical questions, one, almost centenary about the existence of an unavoidable ether in general relativity agreeing with the Mach's principle, and one more recent about the properties of the quantum vacuum of the quantum field theory of strong interactions, QuantumChromodynamics (QCD). According to this idea, on the one hand, dark matter and dark energy that, according to the current standard model of cosmology represent about 95% of the universe content, can be considered as two distinct forms of the Mach's ether, and, on the other hand, dark matter, as a perfect fluid emerging from the QCD vacuum could be modeled as a Bose Einstein condensate.

  7. A numerical method to compute derivatives of functions of large complex matrices and its application to the overlap Dirac operator at finite chemical potential

    CERN Document Server

    Puhr, Matthias

    2016-01-01

    We present a method for the numerical calculation of derivatives of functions of general complex matrices. The method can be used in combination with any algorithm that evaluates or approximates the desired matrix function, in particular with implicit Krylov-Ritz-type approximations. An important use case for the method is the evaluation of the overlap Dirac operator in lattice Quantum Chromodynamics (QCD) at finite chemical potential, which requires the application of the sign function of a non-Hermitian matrix to some source vector. While the sign function of non-Hermitian matrices in practice can not be efficiently approximated with source-independent polynomials or rational functions, sufficiently good approximating polynomials can still be constructed for each particular source vector. Our method allows for an efficient calculation of the derivatives of such implicit approximations with respect to the gauge field or other external parameters, which is necessary for the calculation of conserved lattice cu...

  8. Topics in modern physics theoretical foundations

    CERN Document Server

    Walecka, John Dirk

    2013-01-01

    While the two previous books entitled Introduction to Modern Physics: Theoretical Foundations and Advanced Modern Physics: Theoretical Foundations exposed the reader to the foundations and frontiers of today's physics, the goal of this third volume is to cover in some detail several topics omitted in the essentially linear progression of the first two. This book is divided into three parts. Part 1 is on quantum mechanics. Analytic solutions to the Schrödinger equation are developed for some basic systems. The analysis is then formalized, concluding with a set of postulates for the theory. Part 2 is on applications of quantum mechanics: approximation methods for bound states, scattering theory, time-dependent perturbation theory, and electromagnetic radiation and quantum electrodynamics. Part 3 covers some selected topics in relativistic quantum field theory: discrete symmetries, the Heisenberg picture, and the Feynman rules for quantum chromodynamics. The three volumes in this series taken together provide ...

  9. Structural aspects of quantum field theory and noncommutative geometry

    CERN Document Server

    Grensing, Gerhard

    2013-01-01

    This book is devoted to the subject of quantum field theory. It is divided into two volumes. The first can serve as a textbook on the main techniques and results of quantum field theory, while the second treats more recent developments, in particular the subject of quantum groups and noncommutative geometry, and their interrelation. The first volume is directed at graduate students who want to learn the basic facts about quantum field theory. It begins with a gentle introduction to classical field theory, including the standard model of particle physics, general relativity, and also supergravity. The transition to quantized fields is performed with path integral techniques, by means of which the one-loop renormalization of a self-interacting scalar quantum field, of quantum electrodynamics, and the asymptotic freedom of quantum chromodynamics is treated. In the last part of the first volume, the application of path integral methods to systems of quantum statistical mechanics is covered. The book ends with a r...

  10. Proceedings of the third symposium on science of hadrons under extreme conditions

    International Nuclear Information System (INIS)

    The third symposium on Science of Hadrons under Extreme Conditions, organized by the Research Group for Hadron Science, Advanced Science Research Center, was held at Tokai Research Establishment of JAERI on January 29 to 31, 2001. The symposium was devoted for discussions and presentations of research results in wide variety of hadron physics such as nuclear matter, high-energy nuclear reactions, quantum chromodynamics, neutron stars, supernovae, nucleosynthesis as well as finite nuclei to understand various aspects of hadrons under extreme conditions. Twenty two papers on these topics presented at the symposium, including a special talk on the present status of JAERI-KEK joint project on high-intensity proton accelerator, aroused lively discussions among approximately 40 participants. The 20 of the presented papers are indexed individually. (J.P.N.)

  11. Quark-gluon plasma: Status of heavy ion physics

    Indian Academy of Sciences (India)

    R V Gavai

    2000-07-01

    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, New York of relativistic heavy ion collisions are expected to produce such energy densities, thereby providing us a chance to test the above prediction. After a brief introduction of the necessary theoretical concepts, I will present a critical review of the experimental results already obtained by the various experiments in order to examine whether QGP has already been observed by them.

  12. Gravitino condensation, supersymmetry breaking and inflation

    CERN Document Server

    Houston, N

    2015-01-01

    Motivated by dualistic considerations of the reality of quark condensation in quantum chromodynamics, and the connections of supergravity to the exotic physics of string and M-theory, in this thesis we investigate the dynamical breaking of local supersymmetry via gravitino condensation. We firstly demonstrate non-perturbative gravitino mass generation via this mechanism in flat spacetime, and from this derive the condensate mode wavefunction renormalisation. By then calculating the full canonically normalised one-loop effective potential for the condensate mode about a de Sitter background, we demonstrate that, contrary to claims in the literature, this process may both occur and function in a phenomenologically viable manner. In particular, we find that outside of certain unfortunate gauge choices, the stability of the condensate is intimately tied via gravitational degrees of freedom to the sign of the tree-level cosmological constant. Furthermore, we find that the energy density liberated may provide the n...

  13. Measurement of F_2^{c\\bar{c}} and F_2^{b\\bar{b}} at Low Q^2 and x using the H1 Vertex Detector at HERA

    CERN Document Server

    Aktas, A; Anthonis, T; Aplin, S; Asmone, A; Astvatsatourov, A; Babaev, A; Backovic, S; Bähr, J; Baghdasaryan, A; Baranov, P; Barrelet, E; Bartel, Wulfrin; Baudrand, S; Baumgartner, S; Becker, J; Beckingham, M; Behnke, O; Behrendt, O; Belousov, A; Berger, C; Berger, N; Bizot, J C; Boenig, M O; Boudry, V; Bracinik, J; Brandt, G; Brisson, V; Brown, D P; Bruncko, Dusan; Büsser, F W; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Caron, S; Cassol-Brunner, F; Cerny, K; Cerny, V; Chekelian, V; Contreras, J G; Coughlan, J A; Cox, B E; Cozzika, G; Cvach, J; Dainton, J B; Dau, W D; Daum, K; De Boer, Y; Delcourt, B; de Roeck, A; Desch, Klaus; De Wolf, E A; Diaconu, C; Dodonov, V; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eichler, R; Eisele, F; Ellerbrock, M; Elsen, E; Erdmann, W; Essenov, S; Falkewicz, A; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Ferencei, J; Finke, L; Fleischer, M; Fleischmann, P; Fleming, Y H; Flucke, G; Fomenko, A; Foresti, I; Franke, G; Frisson, T; Gabathuler, E; Garutti, E; Gayler, J; Gerlich, C; Ghazaryan, S; Ginzburgskaya, S; Glazov, A; Glushkov, I; Görlich, L; Göttlich, M; Gogitidze, N; Gorbounov, S; Goyon, C; Grab, C; Greenshaw, T; Gregori, M; Grell, B R; Grindhammer, G; Gwilliam, C; Haidt, D; Hajduk, L; Hansson, M; Heinzelmann, G; Henderson, R C W; Henschel, H; Henshaw, O; Herrera-Corral, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R P; Hovhannisyan, A; Hreus, T; Hussain, S; Ibbotson, M; Ismail, M; Jacquet, M; Janauschek, L; Janssen, X; Jemanov, V; Jönsson, L B; Johnson, D P; Jung, A W; Jung, H; Kapichine, M; Katzy, J; Keller, N; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Klimkovich, T; Kluge, T; Knies, G; Knutsson, A; Korbel, V; Kostka, P; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Krüger, K; Kuckens, J; Landon, M P J; Lange, W; Lastoviicka, T; Lastoviicka-Medin, G; Laycock, P; Lebedev, A; Leibenguth, G; Lendermann, V; Levonian, S; Lindfeld, L; Lipka, K; Liptaj, A; List, B; Lobodzinska, E; Loktionova, N; López-Fernandez, R; Lubimov, V; Lucaci-Timoce, A I; Lüders, H; Lüke, D; Lux, T; Lytkin, L; Makankine, A; Malden, N; Malinovskii, E I; Mangano, S; Marage, P; Marshall, R; Martisikova, M; Martyn, H U; Maxfield, S J; Meer, D; Mehta, A; Meier, K; Meyer, A B; Meyer, H; Meyer, J; Mikocki, S; Milcewicz-Mika, I; Milstead, D; Mladenov, D M; Mohamed, A; Moreau, F; Morozov, A; Morris, J V; Mozer, M U; Müller, K; Murn, P; Nankov, K; Naroska, Beate; Naumann, T; Newman, P R; Niebuhr, C; Nikiforov, A; Nikitin, D; Nowak, G; Nozicka, M; Oganezov, R; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Palichik, V; Panagoulias, I; Papadopoulou, T D; Pascaud, C; Patel, G D; Peez, M; Pérez, E; Perez-Astudillo, D; Perieanu, A; Petrukhin, A; Pitzl, D; Placakyte, R; Portheault, B; Povh, B; Prideaux, P; Raicevic, N; Reimer, P; Rimmer, A; Risler, C; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rurikova, Z; Rusakov, S; Salvaire, F; Sankey, D P C; Sauvan, E; Schatzel, S; Schilling, F P; Schmidt, S; Schmitt, S; Schmitz, C; Schoeffel, L; Schöning, A; Schultz-Coulon, H C; Sedlak, K; Sefkow, F; Shaw-West, R N; Shevyakov, I; Shtarkov, L N; Sloan, T; Smirnov, P; Soloviev, Yu; South, D; Spaskov, V; Specka, A; Stella, B; Stiewe, J; Strauch, I; Straumann, U; Tchoulakov, V; Thompson, G; Thompson, P D; Tomasz, F; Traynor, D; Truöl, P; Tsakov, I; Tsipolitis, G; Tsurin, I; Turnau, J; Tzamariudaki, E; Urban, M; Usik, A; Utkin, D; Valkár, S; Valkárová, A; Vallée, C; Van Mechelen, P; Vargas1, A; Vazdik, Ya A; Veelken, C; Vest, A; Vinokurova, S; Volchinski, V; Vujicic, B; Wacker, K; Wagner, J; Weber, G; Weber, R; Wegener, D; Werner, C; Werner, N; Wessels, M; Wessling, B; Wigmore, C; Wissing, C; Wolf, R; Wünsch, E; Xella, S M; Yan, W; Yeganov, V; Zaicek, J; Zaleisak, J; Zhang, Z; Zhelezov, A; Zhokin, A; Zhu, Y C; Zimmermann, J; Zimmermann, T; Zohrabyan, H; Zomer, F

    2006-01-01

    Measurements are presented of inclusive charm and beauty cross sections in e^+p collisions at HERA for values of photon virtuality 12 \\le Q^2 \\le 60 GeV^2 and of the Bjorken scaling variable 0.0002 \\le x \\le 0.005. The fractions of events containing charm and beauty quarks are determined using a method based on the impact parameter, in the transverse plane, of tracks to the primary vertex, as measured by the H1 vertex detector. Values for the structure functions F_2^{c\\bar{c}} and F_2^{b\\bar{b}} are obtained. This is the first measurement of F_2^{b\\bar{b}} in this kinematic range. The results are found to be compatible with the predictions of perturbative quantum chromodynamics and withprevious measurements of F_2^{c\\bar{c}}.

  14. Measurement of the differential cross section for top quark pair production in pp collisions at √s=8 TeV

    International Nuclear Information System (INIS)

    The normalized differential cross section for top quark pair (tt-bar) production is measured in pp collisions at a centre-of-mass energy of 8 TeV at the CERN LHC using the CMS detector in data corresponding to an integrated luminosity of 19.7 fb-1. The measurements are performed in the lepton+jets (e/μ+jets) and in the dilepton (e+e-, μ+μ-, and e±μ∓) decay channels. The tt-bar cross section is measured as a function of the kinematic properties of the charged leptons, the jets associated to b quarks, the top quarks, and the tt-bar system. The data are compared with several predictions from perturbative quantum chromodynamic up to approximate next-to-next-to-leading-order precision. No significant deviations are observed relative to the standard model predictions

  15. Proceedings of the third symposium on science of hadrons under extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, Satoshi (ed.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-09-01

    The third symposium on Science of Hadrons under Extreme Conditions, organized by the Research Group for Hadron Science, Advanced Science Research Center, was held at Tokai Research Establishment of JAERI on January 29 to 31, 2001. The symposium was devoted for discussions and presentations of research results in wide variety of hadron physics such as nuclear matter, high-energy nuclear reactions, quantum chromodynamics, neutron stars, supernovae, nucleosynthesis as well as finite nuclei to understand various aspects of hadrons under extreme conditions. Twenty two papers on these topics presented at the symposium, including a special talk on the present status of JAERI-KEK joint project on high-intensity proton accelerator, aroused lively discussions among approximately 40 participants. The 20 of the presented papers are indexed individually. (J.P.N.)

  16. Hadron Physics and QCD: Just the Basic Facts

    CERN Document Server

    Roberts, Craig D

    2015-01-01

    With discovery of the Higgs boson, the Standard Model of Particle Physics became complete. Its formulation is a remarkable story; and the process of verification is continuing, with the most important chapter being the least well understood. Quantum Chromodynamics (QCD) is that part of the Standard Model which is supposed to describe all of nuclear physics and yet, almost fifty years after the discovery of quarks, we are only just beginning to understand how QCD moulds the basic bricks for nuclei: pious, neutrons, protons. QCD is characterized by two emergent phenomena: confinement and dynamical chiral symmetry breaking (DCSB), whose implications are extraordinary. This contribution describes how DCSB, not the Higgs boson, generates more than 98% of the visible mass in the Universe, explains why confinement guarantees that condensates, those quantities that were commonly viewed as constant mass-scales that fill all spacetime, are instead wholly contained within hadrons, and elucidates a range of observable co...

  17. People and things. CERN Courier, May 1981, v. 21(4)

    International Nuclear Information System (INIS)

    The article reports on achievements of various people, staff changes and position opportunities within the CERN organization and contains news updates on upcoming or past events. A summer workshop will be held at Brookhaven from 20 to 31 July, with the primary focus on physics opportunities at ISABELLE. Other topics will include experimental areas and large detectors. Experiments which measure muon lifetimes have a habit of being elegant. One illustration of this is the new result from a Bologna/CERN/ Saclay/TRIUMF collaboration giving a precision value for the muon capture rate in hydrogen. The ninth annual SLAC Summer Institute, to be held from 27 July to 7 August, is to be given over to strong interactions, and quantum chromodynamics in particular. Results from hadron production and spectroscopy experiments will be reviewed with emphasis on heavy quark systems and jet production

  18. A new observable to measure the top-quark mass at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Alioli, S. [Lawrence Berkeley National Lab., CA (United States); California Univ., Berkeley, CA (United States); Fernandez, P.; Fuster, J.; Irles, A.; Vos, M. [Valencia Univ. (Spain). IFIC; CSIC, Paterna (Spain); Moch, S. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Uwer, P. [Humboldt-Universitaet, Berlin (Germany)

    2013-03-15

    A new method to measure the top-quark mass in high energetic hadron collisions is presented. We use theoretical predictions calculated at next-to-leading order accuracy in quantum chromodynamics to study the (normalized) differential distribution of the t anti t+1-jet cross section with respect to its invariant mass {radical}(s{sub t} {sub anti} {sub tj}). The sensitivity of the method to the top-quark mass together with the impact of various theoretical and experimental uncertainties has been investigated and quantified. The new method allows for a complementary measurement of the top-quark mass parameter and has a high potential to become competitive in precision with respect to established approaches. Furthermore we emphasize that in the proposed method the mass parameter is uniquely defined through one-loop renormalization.

  19. QCD and resonance physics. Vector nonet

    International Nuclear Information System (INIS)

    The quantum chromodynamics (QCD) sum rules are applied to evaluate masses and leptonic widths of the ω, γ, K* mesons. The general approach is the same as for the rho meson discussed earlier. The key parameter responsible for the SU(3) breaking is msub(s) where msub(s) is the strange quark mass, q is a quark field. The expected accuracy of the results obtained is about +-10% and the experimental masses fall within these limits. For leptonic widths better experimental accuracy is desired. Sum rules provide an explanation for the ω-rho degeneracy and allow for an estimate of the ω-rho mixing. The smallness of the ω-rho mixing is well understood and a reasonable value for it emerges. Comparison of the QCD sum rules with some other approaches to the resonance physics is presented

  20. Physics of the 1 Teraflop RIKEN-BNL-Columbia QCD project. Proceedings of RIKEN BNL Research Center workshop: Volume 13

    International Nuclear Information System (INIS)

    A workshop was held at the RIKEN-BNL Research Center on October 16, 1998, as part of the first anniversary celebration for the center. This meeting brought together the physicists from RIKEN-BNL, BNL and Columbia who are using the QCDSP (Quantum Chromodynamics on Digital Signal Processors) computer at the RIKEN-BNL Research Center for studies of QCD. Many of the talks in the workshop were devoted to domain wall fermions, a discretization of the continuum description of fermions which preserves the global symmetries of the continuum, even at finite lattice spacing. This formulation has been the subject of analytic investigation for some time and has reached the stage where large-scale simulations in QCD seem very promising. With the computational power available from the QCDSP computers, scientists are looking forward to an exciting time for numerical simulations of QCD