Standard candle central exclusive processes at the Tevatron and LHC
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2010-01-01
Central exclusive production (CEP) processes in high-energy proton -- (anti)proton collisions offer a very promising framework within which to study both novel aspects of QCD and new physics signals. Among the many interesting processes that can be studied in this way, those involving the production of heavy (c,b) quarkonia and gamma gamma states have sufficiently well understood theoretical properties and sufficiently large cross sections that they can serve as `standard candle' processes with which we can benchmark predictions for new physics CEP at the CERN Large Hadron Collider. Motivated by the broad agreement with theoretical predictions of recent CEP measurements at the Fermilab Tevatron, we perform a detailed quantitative study of heavy quarkonia (chi and eta) and gamma gamma production at the Tevatron, RHIC and LHC, paying particular attention to the various uncertainties in the calculations. Our results confirm the rich phenomenology that these production processes offer at present and future high-e...
Central Exclusive Production at LHCb
McNulty, Ronan
2015-01-01
Central Exclusive Production is a unique QCD process in which particles are produced via colourless propagators. Several results have been obtained at LHCb for the production of single charmonia, pairs of charmonia, and single bottomonia.
Generation of central exclusive final states
Lönnblad, Leif
2016-01-01
We present a scheme for the generation of central exclusive final states in the Pythia 8 program. The implementation allows for the investigation of higher order corrections to such exclusive processes as approximated by the initial-state parton shower in Pythia 8. To achieve this, the spin and colour decomposition of the initial-state shower has been worked out, in order to determine the probability that a partonic state generated from an inclusive sub-process followed by a series of initial-state parton splittings can be considered as an approximation of an exclusive colour- and spin-singlet process. We use our implementation to investigate effects of parton showers on some examples of central exclusive processes, and find sizeable effects on di-jet production, while the effects on e.g. central exclusive Higgs production are minor.
Central exclusive production at RHIC
Adamczyk, Leszek; Guryn, Włodek; Turnau, Jacek
2014-11-01
The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment's Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at √ {s} = 200 GeV. The preliminary spectra of two-pion mass reconstructed by STAR TPC in central region of pseudorapidity |η| < 1, are presented. Near future plans to take data with the current system at center-of-mass energy √ {s} = 200 GeV and plans to upgrade the forward proton tagging system are presented. Also a possible addition of the RPs to the sPHENIX detector is discussed.
Central Exclusive Production at LHCb
McNulty, Ronan
2016-01-01
Central Exclusive Production (CEP) is a unique process at hadron machines in which particles are produced via colourless propagators. LHCb have measured the cross-sections for the CEP of vector mesons, $J/\\psi,\\psi(2S),\\Upsilon(1S),\\Upsilon(2S)$ and $\\Upsilon(3S)$, which are photo-produced. In the double pomeron exchange process, preliminary measurements have been made of $\\chi_{c0},\\chi_{c1}, \\chi_{c2}$ meson production while the first observations of the CEP of pairs of charmonia, $J/\\psi J/\\psi$ and $J/\\psi \\psi(2S)$, have been made and limits obtained on the pair production of other charmonia.
Exclusive Processes at Colliders
Szczurek, Antoni
2009-01-01
A few examples of exclusive processes at high energy are discussed. Several mechanisms are presented. The differential distributions are shown. The possibilities to measure the processes are discussed.
Kugler, W.
2007-01-15
Hard exclusive processes in high energy electron proton scattering offer the opportunity to get access to a new generation of parton distributions, the so-called generalized parton distributions (GPDs). This functions provide more detailed informations about the structure of the nucleon than the usual PDFs obtained from DIS. In this work we present a detailed analysis of exclusive processes, especially of hard exclusive meson production. We investigated the influence of exclusive produced mesons on the semi-inclusive production of mesons at fixed target experiments like HERMES. Further we give a detailed analysis of higher order corrections (NLO) for the exclusive production of mesons in a very broad range of kinematics. (orig.)
Central Exclusive Production at the LHC
Forshaw, J R
2009-01-01
After a brief resume of the theory underpinning the central exclusive process (CEP) pp \\to p+H+p, attention is focussed upon Higgs bosons produced in the Standard Model, the MSSM and the NMSSM. In all cases, CEP adds significantly to the physics potential of the LHC and in some scenarios it may be crucial.
A study of Central Exclusive Production
Monk, James; /Manchester U.
2008-09-01
Central exclusive production of a system X in a collision between two hadrons h is defined as hh {yields} h + X + h with no other activity apart from the decay products of X. This thesis presents predictions for the production cross section of a CP violating supersymmetric Higgs boson and the radion of the Randall-Sundrum model. The ExHuME Monte Carlo generator was written to simulate central exclusive processes and is described and explored. A comparison to di-jet observations made by the D0 detector at the Tevatron, Fermilab between January and June 2004 is made and the distributions found support the predictions of ExHuME.
CERN Summer Student Project: Central Exclusive Diffraction and Glueball Searches
van Beest, Marieke
2016-01-01
CERN Summer Student work project report on work conducted in the Diffraction group at the ALICE experiment as well as the obtained results. These include a kinematical calculation with respect to a generic central exclusive process, the selection rules for a centrally produced system with respect to a specific central exclusive diffraction process, and finally a case study of one of the first contributions to the search for glueballs at CERN.
Latest Results in Central Exclusive Production: A Summary
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2013-01-01
Selected new results in central exclusive production (CEP) processes within the pQCD-based Durham model are discussed. Topics covered include the CEP of SM and BSM Higgs-like particles, meson pair CEP and the gap survival probability.
Central exclusive meson pair production in the perturbative regime
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2011-01-01
We present a study of the central exclusive production (CEP) of meson pairs, MMbar, at sufficiently high invariant mass that a perturbative QCD formalism is applicable. Within this framework, MMbar production proceeds via the gg --> MMbar hard scattering sub-process, which can be calculated within the hard exclusive formalism. We present explicit calculations for the gg --> MMbar helicity amplitudes for different meson states and, using these, show results for meson pair CEP in the perturbative regime.
Mini review of Central Exclusive Production at LHC
Brona, Grzegorz
2009-01-01
The LHC experiments provide an unprecedented coverage in pseudo-rapidity. This advantage and the high LHC luminosity allow for broad studies of central exclusive production (CEP) \\mbox{processes} such as exclusive production of $\\Upsilon$, di-leptons, di-photons and di-jets. With the proposed near beam detectors (FP420 and FP220) exclusive Higgs and SUSY states will be also \\mbox{accesible}. The \\mbox{discussion} is focused on the CMS programme, but both CMS and ATLAS have similar \\mbox{kinematical} coverage and may perform similar studies.
Mini review of Central Exclusive Production at LHC
Brona, Grzegorz
2009-01-01
The LHC experiments provide an unprecedented coverage in pseudo-rapidity. This advantage and high LHC luminosity allow for broad studies of central exclusive production (CEP) processes such as exclusive production of ¡, di-leptons, di-photons and di-jets. Finally, with the proposed near beam detectors (FP420 and FP220) the exclusive Higgs and SUSY states will be also accesible. The discussion is focused on the CMS programme, as both CMS and ATLAS have similar kinematical coverage and may perform similar studies.
Central exclusive production within the Durham model: a review
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2014-01-01
We review recent results within the Durham model of central exclusive production. We discuss the theoretical aspects of this approach and consider the phenomenological implications in a variety of processes, comparing to existing collider data and addressing the possibilities for the future.
Central exclusive production within the Durham model: A Review
Harland-Lang, L. A.; Khoze, V. A.; Ryskin, M. G.; Stirling, W. J.
2014-06-01
We review recent results within the Durham model of central exclusive production. We discuss the theoretical aspects of this approach and consider the phenomenological implications in a variety of processes, comparing to existing collider data and addressing the possibilities for the future.
Exclusive processes in quantum chromodynamics
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
Exclusive Photon-Photon Processes
S. J. Brodsky
1997-01-01
Exclusive $\\gamma\\gamma \\to$ hadron pairs are among the most fundamental processes in QCD, providing a detailed examination of Compton scattering in the crossed channel. In the high momentum transfer domain $(s,t, {large},\\theta_{cm}$ for $t/s$ fixed), these processes can be computed from first principles in QCD, yielding important information on the nature of the QCD coupling $\\alpha_s$ and the form of hadron distribution amplitudes. Similarly, the transition form factors $\\gamma^*\\gamma$, $...
Exclusive processes at Jefferson Lab
Haiyan Gao
2003-11-01
Mapping the transition from strongly interacting, non-perturbative quantum chromodynamics, where nucleon–meson degrees of freedom are effective to perturbative QCD of quark and gluon degrees of freedom, is one of the most fundamental, challenging tasks in nuclear and particle physics. Exclusive processes such as proton–proton elastic scattering, meson photoproduction, and deuteron photodisintegration have been pursued extensively at many laboratories over the years in the search for such a transition, particularly at Jefferson Lab in recent years, taking the advantage of the high luminosity capability of the CEBAF facility. In this talk, I review recent results from Jefferson Lab on deuteron photodisintegration and photopion production processes and the future 12 GeV program.
Central exclusive production in the ALICE experiment at the LHC
Schicker, R
2014-01-01
The ALICE experiment at the Large Hadron Collider (LHC) at CERN consists of a central barrel, a muon spectrometer and additional detectors for trigger and event classification purposes. The low transverse momentum threshold of the central barrel gives ALICE a unique opportunity to study the low mass sector of central exclusive production at the LHC.
HERMES Measurements of Hard-Exclusive Processes
Marianski, Bohdan
2008-11-15
Three HERMES measurements of hard-exclusive processes usefull for testing Generalized Parton Distributions (GPDs) are described. Firstly, Spin Density Matrix Elements (SDMEs) are determined from exclusive diffractive {rho}{sup 0} and {phi} electroproduction in the HERMES experiment at 27.5 GeV beam energy. Then, Transverse Target Spin Asymmetry (TTSA) in exclusive {rho}{sup 0} production and in Deeply Virtual Compton Scattering (DVCS) process on a transversally polarized hydrogen target is determined.
Central Exclusive Production in pp collisions at LHCb
McNulty, Ronan
2016-03-01
Central Exclusive Production (CEP) is a unique process at hadron machines in which particles are produced via colourless propagators, and several measurements at the LHC are directly comparable with past and future electron-ion colliders. LHCb have measured the cross-sections for the CEP of vector mesons, J/ψ,ψ (2S),ϒ(1S), ϒ(2S) and ϒ(3S), which are photo-produced. In the double Pomeron exchange process, preliminary measurements have been made of χc0, χc1, χc2 meson production while the first observations of the CEP of pairs of charmonia, J/ψJ/ψ and J/ψψ (2S), have been made and limits obtained on the pair production of other charmonia.
Central Exclusive Production of $\\chi$ Mesons at LHCb
Bjornstad, Pal Marius
The LHCb experiment is a forward spectrometer at the Large Hadron Collider, covering a range of pseudorapidity $1.9<\\eta<4.9$. It has a very precise vertex detector called the VELO, near the interaction point. The monitoring software for the VELO is discussed in this thesis. In proton-proton interactions, Central Exclusive Production (CEP) is a process where the protons remain intact after the interaction, and an additional simple central system is produced. CEP processes are selected experimentally by requiring that there is no activity in the detector apart from the central system. The installation of additional detectors to increase the sensitivity at small angles from the beam axis is discussed. A geometrical description of the region of the LHC up to $100$~m on each side of the LHCb interaction point is developed. Simulated forward shower counters are added to the model, and the efficiencies of the detectors are measured. The main part of this thesis describes an analysis of CEP of $\\chi_c$ mes...
Perspectives on Exclusive Processes in QCD
Brodsky, Stanley J.
2002-01-01
Hard hadronic exclusive processes are now at the forefront of QCD studies, particularly because of their role in the interpretation of exclusive hadronic B decays. Perturbative QCD and its factorization properties at high momentum transfer provide an essential guide to the phenomenology of exclusive amplitudes at large momentum transfer--the leading power fall-off of form factors and fixed-angle cross sections, the dominant helicity structures, and their color transparency properties. The har...
The phenomenology of central exclusive production at hadron colliders
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2012-01-01
Central exclusive production (CEP) processes in high-energy hadron-hadron collisions provide an especially clean environment in which to measure the nature and quantum numbers (in particular, the spin and parity) of new resonance states. Encouraged by the broad agreement between experimental measurements and theoretical predictions based on the Durham approach, we perform a detailed phenomenological analysis of diphoton and meson pair CEP final states, paying particular attention to the theoretical uncertainties in the predictions, including those from parton distribution functions, higher-order perturbative corrections, and non-perturbative and proton dissociation contributions. We present quantitative cross-section predictions for these CEP final states at the RHIC, Tevatron and LHC colliders.
Exclusive processes at high momentum transfer
Radyushkin, Anatoly; Stoker, Paul
2002-01-01
This book focuses on the physics of exclusive processes at high momentum transfer and their description in terms of generalized parton distributions, perturbative QCD, and relativistic quark models. It covers recent developments in the field, both theoretical and experimental.
Imaging partons in exclusive scattering processes
Diehl, Markus
2012-06-15
The spatial distribution of partons in the proton can be probed in suitable exclusive scattering processes. I report on recent performance estimates for parton imaging at a proposed Electron-Ion Collider.
Overview of HERMES Results on Exclusive Processes
Movsisyan Aram
2015-01-01
An overview of HERMES results on measurements of hard exclusive electroproduction of real photons and mesons on hydrogen and deuterium targets is presented. Experimental measurements of hard exclusive processes are commonly described within the formalism of generalized parton distributions (GPDs), which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs) and transverse-position information (form factors). The HERMES experimen...
Exclusive hadronic and nuclear processes in QCD
Hadronic and nuclear processes are covered, in which all final particles are measured at large invariant masses compared with each other, i.e., large momentum transfer exclusive reactions. Hadronic wave functions in QCD and QCD sum rule constraints on hadron wave functions are discussed. The question of the range of applicability of the factorization formula and perturbation theory for exclusive processes is considered. Some consequences of quark and gluon degrees of freedom in nuclei are discussed which are outside the usual domain of traditional nuclear physics. 44 refs., 7 figs
Overview of HERMES Results on Exclusive Processes
Movsisyan, Aram
2015-01-01
An overview of HERMES results on measurements of hard exclusive electroproduction of real photons and mesons on hydrogen and deuterium targets is presented. Experimental measurements of hard exclusive processes are commonly described within the formalism of generalized parton distributions (GPDs), which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs) and transverse-position information (form factors). The HERMES experiment at DESY Hamburg studies hard exclusive processes using polarized electron or positron beams from HERA and internal gas targets. Information about GPDs is gained from the measurements of asymmetries that appear in the azimuthal distributions of produced mesons and photons, together with studies of the azimuthal distribution of the decay products via spin-density matrix elements.
Overview of HERMES Results on Exclusive Processes
Movsisyan Aram
2015-01-01
Full Text Available An overview of HERMES results on measurements of hard exclusive electroproduction of real photons and mesons on hydrogen and deuterium targets is presented. Experimental measurements of hard exclusive processes are commonly described within the formalism of generalized parton distributions (GPDs, which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs and transverse-position information (form factors. The HERMES experiment at DESY Hamburg studies hard exclusive processes using polarized electron or positron beams from HERA and internal gas targets. Information about GPDs is gained from the measurements of asymmetries that appear in the azimuthal distributions of produced mesons and photons, together with studies of the azimuthal distribution of the decay products via spin-density matrix elements.
Perspectives on Exclusive Processes in QCD
Brodsky, S J
2002-01-01
Hard hadronic exclusive processes are now at the forefront of QCD studies, particularly because of their role in the interpretation of exclusive hadronic B decays. Perturbative QCD and its factorization properties at high momentum transfer provide an essential guide to the phenomenology of exclusive amplitudes at large momentum transfer--the leading power fall-off of form factors and fixed-angle cross sections, the dominant helicity structures, and their color transparency properties. The hard scattering subprocess amplitude T_H controlling the leading-twist amplitude is evaluated in the perturbative domain where the propagator virtualities are above the separation scale. A critical question is the momentum transfer required such that leading-twist perturbative QCD contributions dominate. I review some of the contentious theoretical issues and empirical challenges to Perturbative QCD based analyses, such as the magnitude of the leading-twist contributions, the role of soft and higher twist QCD mechanisms, the...
Observation of Central Exclusive Diphoton Production at the Tevatron
Brucken, Jens Erik [Univ. of Helsinki (Finland); Helsinki Inst. of Physics (Finland)
2013-01-01
We have observed exclusive γγ production in proton-antiproton collisions at the Tevatron at √ s = 1.96 TeV. We use data corresponding to 1.11 ± 0.07 fb-1 integrated luminosity taken by the Run II Collider Detector at Fermilab, with a trigger requiring two electromagnetic showers, each with transverse energy ET > 2 GeV, and vetoing on hits in the forward beam shower counters. We select events with two electromagnetic showers, each with transverse energy ET > 2.5 GeV and pseudorapidity |η| < 1.0, with no other particles detected in -7.4 < η < +7.4. The two showers have similar ET and an azimuthal angle separation Δφ ~ π; we find 34 events with exactly two matching charged particle tracks, agreeing with expectations for the QED process p¯p → p+e+e- + ¯p by two photon exchange; and we find 43 events with no tracks. The latter are candidates for the exclusive process p¯p → p + γγ + ¯p by double pomeron exchange. We use the strip and wire chambers at the longitudinal shower maximum position within the calorimeter to measure a possible exclusive background from IP + IP → π0π0, and conclude that it is consistent with zero and is < 15 events at 95% C.L. The measured cross section is σγγ,excl(|η| < 1, ET (γ) > 2.5 GeV) = 2.48 +0.40 -0.35(stat) +0.40 -0.51(syst) pb and in agreement with the theoretical predictions. This process is closely related to exclusive Higgs boson production pp → p + H + p at the Large Hadron Collider. The observation of the exclusive production of diphotons shows that exclusive Higgs production can happen and could be observed with a proper experimental setup.
Dynamics of non-Markovian exclusion processes
Khoromskaia, Diana; Rosemary J. Harris; Grosskinsky, Stefan
2014-01-01
Driven diffusive systems are often used as simple discrete models of collective transport phenomena in physics, biology or social sciences. Restricting attention to one-dimensional geometries, the asymmetric simple exclusion process (ASEP) plays a paradigmatic role to describe noise-activated driven motion of entities subject to an excluded volume interaction and many variants have been studied in recent years. While in the standard ASEP the noise is Poissonian and the process is therefore Ma...
Central exclusive meson pair production in the perturbative regime at hadron colliders
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2011-01-01
The central exclusive production (CEP) of heavy resonance states that subsequently decay into meson pairs, MMbar, is an important signature for such processes at hadron colliders. However there is a potentially important background from the direct QCD production of meson pairs, as mediated for example by the exclusive gg --> MMbar hard scattering subprocess. This is in fact an interesting process in its own right, testing novel aspects of perturbative QCD technology. We explicitly calculate the gg --> MMbar helicity amplitudes for different meson states within the hard exclusive formalism, and comment on the application of MHV techniques to the calculation. Using these results, we describe how meson pair CEP can be calculated in the perturbative regime, and present some sample numerical predictions for a variety of final states. We also briefly consider the dominant non-perturbative contributions, which are expected to be important when the meson transverse momentum is small.
Perspectives on Exclusive Processes in QCD
Brodsky, S. J.
2002-12-01
Hard hadronic exclusive processes are now at the forefront of QCD studies, particularly because of their role in the interpretation of exclusive hadronic B decays, processes which are essential for determining the CKM phases and the physics of CP violation. Perturbative QCD and its factorization properties at high momentum transfer provide an essential guide to the phenomenology of exclusive amplitudes at large momentum transfer--the leading power fall-off of form factors and fixed-angle cross sections, the dominant helicity structures, and their color transparency properties. The reduced amplitude formalism provides an extension of the perturbative QCD predictions to exclusive nuclear amplitudes. The hard scattering subprocess TH controlling the leading-twist amplitude is only evaluated in the QCD perturbative domain where the propagator virtualities are above the separation scale. A critical question is the momentum transfer required such that leading-twist perturbative QCD contributions dominate. I review some of the contentious theoretical issues and empirical challenges to Perturbative QCD based analyses, such as the magnitude of the leading-twist contributions, the role of soft and higher twist QCD mechanisms, the effects of non-zero orbital angular momentum, the possibility of single-spin asymmetries in deeply virtual Compton scattering, the role of hidden color in nuclear wavefunctions, the behavior of the ratio of Pauli and Dirac nucleon form factors, the origin of anomalous J/ψ decays, the apparent breakdown of color transparency in quasi-elastic proton-proton scattering, and the measurement of hadron and photon wavefunctions in diffractive dijet production.
Perspectives on Exclusive Processes in QCD
Hard hadronic exclusive processes are now at the forefront of QCD studies, particularly because of their role in the interpretation of exclusive hadronic B decays, processes which are essential for determining the CKM phases and the physics of CP violation. Perturbative QCD and its factorization properties at high momentum transfer provide an essential guide to the phenomenology of exclusive amplitudes at large momentum transfer---the leading power fall-off of form factors and fixed-angle cross sections, the dominant helicity structures, and their color transparency properties. The reduced amplitude formalism provides an extension of the perturbative QCD predictions to exclusive nuclear amplitudes. The hard scattering subprocess TH controlling the leading-twist amplitude is only evaluated in the QCD perturbative domain where the propagator virtualities are above the separation scale. A critical question is the momentum transfer required such that leading-twist perturbative QCD contributions dominate. I review some of the contentious theoretical issues and empirical challenges to Perturbative QCD based analyses, such as the magnitude of the leading-twist contributions, the role of soft and higher twist QCD mechanisms, the effects of non-zero orbital angular momentum, the possibility of single-spin asymmetries in deeply virtual Compton scattering, the role of hidden color in nuclear wavefunctions, the behavior of the ratio of Pauli and Dirac nucleon form factors, the origin of anomalous J/ψ decays, the apparent breakdown of color transparency in quasi-elastic proton-proton scattering, and the measurement of hadron and photon wavefunctions in diffractive dijet production
Asymptotic behaviour of exclusive processes in QCD
The main ideas, methods and results in the investigation of the asymptotic behaviour of exclusive processes are reviewed. We discuss power behaviour and its dependence on hadron quantum numbers, logarithmic corrections and properties of nonperturbative hadronic wave functions. Applications to meson and baryon form factors, strong, electromagnetic and weak decays of heavy mesons, elastic scattering, threshold behaviour of inclusive structure functions, etc., are described. Comparison of theoretical predictions with experimental data is made whenever possible. The review may be of interest to theoreticians, experimentalists and students specializing in elementary particle physics. The experts in this field can also find new results (nonleading logarithms, higher twist processes, novel applications, etc.). (orig.)
Facilitated exclusion process and Pfaffian Schur processes
Baik, Jinho; Barraquand, Guillaume; Corwin, Ivan; Suidan, Toufic
2016-01-01
We study the Facilitated TASEP, an interacting particle system on the one dimensional integer lattice. We prove that starting from step initial condition, the position of the rightmost particle has Tracy Widom GSE statistics on a cube root time scale, while the statistics in the bulk of the rarefaction fan are GUE. This uses a mapping with last-passage percolation in a half-quadrant, which we study using the formalism of Pfaffian Schur processes. For the model with exponential weights, we pro...
Death to perturbative QCD in exclusive processes?
Eckardt, R.; Hansper, J.; Gari, M.F. [Institut fuer Theoretische Physik, Bochum (Germany)
1994-04-01
The authors discuss the question of whether perturbative QCD is applicable in calculations of exclusive processes at available momentum transfers. They show that the currently used method of determining hadronic quark distribution amplitudes from QCD sum rules yields wave functions which are completely undetermined because the polynomial expansion diverges. Because of the indeterminacy of the wave functions no statement can be made at present as to whether perturbative QCD is valid. The authors emphasize the necessity of a rigorous discussion of the subject and the importance of experimental data in the range of interest.
An exclusion process with dynamic roadblocks
Ning, Guo; Jin-Yong, Chen; Mao-Bin, Hu; Rui, Jiang
2016-06-01
We study an exclusion process with multiple dynamic roadblocks. Each roadblock can move diffusively forward or backward with different rates, as well as unbind from/rebind to a free site. By Monte Carlo simulations, the two moving types are investigated in combination of roadblock number. The case of only diffusive roadblocks shows an asymmetric current-density relation. The case of only long-range jumping roadblocks presents that flux decreases with increasing roadblock number. Project supported by the National Basic Research Program of China (Grant No. 2012CB725404) and the National Natural Science Foundation of China (Grant Nos. 11422221, 71171185, and 71371175).
Exclusion type spatially heterogeneous processes in continuum
Blank, Michael
2011-01-01
We study deterministic discrete time exclusion type spatially heterogeneous particle processes in continuum. A typical example of this sort is a traffic flow model with obstacles: traffic lights, speed bumps, spatially varying local velocities etc. Ergodic averages of particle velocities are obtained and their connections to other statistical quantities, in particular to particle and obstacles densities (the so called Fundamental Diagram) is analyzed rigorously. The main technical tool is a "dynamical" coupling construction applied in a nonstandard fashion: instead of proving the existence of the successful coupling (which even might not hold) we use its presence/absence as an important diagnostic tool.
Central exclusive quarkonium production with tagged forward protons at RHIC
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2010-01-01
We study the Central Exclusive Production (CEP) of chi_cJ and eta_c mesons at RHIC in proton-proton collisions. We consider the chi_cJ --> J/psi + gamma decay channels and, recalling that the J_z=0 suppression of the J=1,2 states can be compensated by their larger branchings to J/psi + gamma, present predictions of rates and distributions for chi_c(0,1,2) production. Particular attention is paid to the impact of p_t cuts applied to the outgoing protons, which can influence the relative rates significantly. The distribution in the azimuthal angle difference between the outgoing protons and the proton p_t^2 is also studied, and shown to depend sensitively on the spin and parity of the centrally produced meson, as well as being affected by the soft survival factors, S^2. Two- and four-body decays, which are particularly relevant for chi_c0 production, are also considered. We show that in the two-body case, backgrounds from `direct' QCD production based on both perturbative and non-perturbative models are expecte...
Generalized parton distributions and exclusive processes
Guzey, Vadim [Hampton U.
2013-10-01
In last fifteen years, GPDs have emerged as a powerful tool to reveal such aspects of the QCD structure of the nucleon as: - 3D parton correlations and distributions; - spin content of the nucleon. Further advances in the field of GPDs and hard exclusive processes rely on: - developments in theory and new methods in phenomenology such as new flexible parameterizations, neural networks, global QCD fits - new high-precision data covering unexplored kinematics: JLab at 6 and 12 GeV, Hermes with recoil detector, Compass, EIC. This slide-show presents: Nucleon structure in QCD, particularly hard processes, factorization and parton distributions; and a brief overview of GPD phenomenology, including basic properties of GPDs, GPDs and QCD structure of the nucleon, and constraining GPDs from experiments.
Asymmetric exclusion processes with shuffled dynamics
The asymmetric simple exclusion process (ASEP) with periodic boundary conditions is investigated for shuffled dynamics. In this type of update, in each discrete timestep the particles are updated in a random sequence. Such an update is important for several applications, e.g., for certain models of pedestrian flow in two dimensions. For the ASEP with shuffled dynamics and a related truncated process exact results are obtained for deterministic motion (p = 1). Since the shuffled dynamics is intrinsically stochastic, also this case is nontrivial. For the case of stochastic motion (0 < p < 1) it is shown that, in contrast to all other updates studied previously, the ASEP with shuffled update does not have a product measure steady state. Approximative formulae for the steady-state distribution and fundamental diagram are derived that are in very good agreement with simulation data
Exclusive central diffractive production of scalar, pseudoscalar and vector mesons
Lebiedowicz P.
2014-01-01
Full Text Available We discuss exclusive central diffractive production of scalar (ƒ0(980, ƒ0(1370, ƒ0(1500, pseudoscalar (η, η′(958, and vector (ρ0 mesons in proton-proton collisions. The amplitudes are formulated in terms of effective vertices required to respect standard rules of Quantum Field Theory and propagators for the exchanged pomeron and reggeons. Different pomeron-pomeron-meson tensorial (vectorial coupling structures are possible in general. In most cases two lowest orbital angular momentum - spin couplings are necessary to describe experimental differential distributions. For the ƒ0(980 and η production the reggeon-pomeron, pomeron-reggeon, and reggeon-reggeon exchanges are included in addition, which seems to be necessary at relatively low energies. The theoretical results are compared with the WA102 experimental data, in order to determine the model parameters. For the ρ0 production the photon-pomeron and pomeron-photon exchanges are considered. The coupling parameters of tensor pomeron and/or reggeon are fixed from the H1 and ZEUS experimental data of the γp → ρ0 p reaction. We present first predictions of this mechanism for pp → ppπ+π− reaction being studied at COMPASS, RHIC, Tevatron, and LHC. Correlation in azimuthal angle between outgoing protons and distribution in pion rapidities at √s = 7 TeV are presented. We show that high-energy central production of mesons could provide crucial information on the spin structure of the soft pomeron.
A Study of Central Exclusive Production at LHCb
AUTHOR|(INSPIRE)INSPIRE-00392718
This thesis presents an analysis of the central exclusive production (CEP) of $\\chi_{\\mathrm{c}}(1\\mathrm{P})$ mesons in proton-proton collisions at a centre-of-mass energy of 8 TeV, using data collected with the LHCb detector corresponding to an effective integrated luminosity of $(126.3 \\pm 4.3)$ pb$^{-1}$. Candidate $\\chi_{\\mathrm{c}}(1\\mathrm{P})$ decays are reconstructed in the $K^+K^-$ and $\\pi^+\\pi^-$ final states, where the final state particles have pseudorapidities between 2.5 and 4.5. The products of the cross sections and branching fractions are measured as \\begin{equation} \\sigma\\times\\mathcal{B}(\\chi_{\\mathrm{c}0}(1\\mathrm{P}) \\rightarrow K^+K^-) = 28.0 \\pm 2.8 \\pm 13.9\\,\\mathrm{pb}, \\end{equation} \\begin{equation} \\sigma\\times\\mathcal{B}(\\chi_{\\mathrm{c}0}(1\\mathrm{P}) \\rightarrow \\pi^+\\pi^-) = 20.3 \\pm 2.4 \\pm 8.1\\,\\mathrm{pb}, \\end{equation} \\begin{equation} \\sigma\\times\\mathcal{B}(\\chi_{\\mathrm{c}2}(1\\mathrm{P}) \\rightarrow K^+K^-) < 12.1\\,\\mathrm{pb}, \\end{equation} \\begin{equation} \\sig...
Dynamics of non-Markovian exclusion processes
Driven diffusive systems are often used as simple discrete models of collective transport phenomena in physics, biology or social sciences. Restricting attention to one-dimensional geometries, the asymmetric simple exclusion process (ASEP) plays a paradigmatic role to describe noise-activated driven motion of entities subject to an excluded volume interaction and many variants have been studied in recent years. While in the standard ASEP the noise is Poissonian and the process is therefore Markovian, in many applications the statistics of the activating noise has a non-standard distribution with possible memory effects resulting from internal degrees of freedom or external sources. This leads to temporal correlations and can significantly affect the shape of the current-density relation as has been studied recently for a number of scenarios. In this paper we report a general framework to derive the fundamental diagram of ASEPs driven by non-Poissonian noise by using effectively only two simple quantities, viz., the mean residual lifetime of the jump distribution and a suitably defined temporal correlation length. We corroborate our results by detailed numerical studies for various noise statistics under periodic boundary conditions and discuss how our approach can be applied to more general driven diffusive systems. (paper)
Dynamics of non-Markovian exclusion processes
Khoromskaia, Diana; Harris, Rosemary J.; Grosskinsky, Stefan
2014-12-01
Driven diffusive systems are often used as simple discrete models of collective transport phenomena in physics, biology or social sciences. Restricting attention to one-dimensional geometries, the asymmetric simple exclusion process (ASEP) plays a paradigmatic role to describe noise-activated driven motion of entities subject to an excluded volume interaction and many variants have been studied in recent years. While in the standard ASEP the noise is Poissonian and the process is therefore Markovian, in many applications the statistics of the activating noise has a non-standard distribution with possible memory effects resulting from internal degrees of freedom or external sources. This leads to temporal correlations and can significantly affect the shape of the current-density relation as has been studied recently for a number of scenarios. In this paper we report a general framework to derive the fundamental diagram of ASEPs driven by non-Poissonian noise by using effectively only two simple quantities, viz., the mean residual lifetime of the jump distribution and a suitably defined temporal correlation length. We corroborate our results by detailed numerical studies for various noise statistics under periodic boundary conditions and discuss how our approach can be applied to more general driven diffusive systems.
Gotsman, E.; Maor, U. [Tel Aviv University, Department of Particle Physics, Raymond and Beverly Sackler Faculty of Exact Science, School of Physics and Astronomy, Tel Aviv (Israel); Levin, E. [Tel Aviv University, Department of Particle Physics, Raymond and Beverly Sackler Faculty of Exact Science, School of Physics and Astronomy, Tel Aviv (Israel); Universidad Tecnica Federico Santa Maria, Departemento de Fisica, Centro Cientifico-Tecnologico de Valparaiso, Valparaiso (Chile)
2016-04-15
We estimate the value of the survival probability for central exclusive production in a model which is based on the CGC/saturation approach. Hard and soft processes are described in the same framework. At LHC energies, we obtain a small value for the survival probability. The source of the small value is the impact parameter dependence of the hard amplitude. Our model has successfully described a large body of soft data: elastic, inelastic and diffractive cross sections, inclusive production and rapidity correlations, as well as the t-dependence of deep inelastic diffractive production of vector mesons. (orig.)
Central Diffractive Processes at the Tevatron, RHIC and LHC
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2011-01-01
Central exclusive production (CEP) processes in high-energy hadron collisions offer a very promising framework for studying both novel aspects of QCD and new physics signals. We report on the results of a theoretical study of the CEP of heavy quarkonia (chi and eta) at the Tevatron, RHIC and LHC. These processes provide important information on the physics of bound states and can probe the current ideas and methods of QCD, such as effective field theories and lattice QCD.
Two-Photon Exclusive Processes in QCD
Brodsky, Stanley J.
2000-01-01
Exclusive two-photon reactions such as Compton scattering at large angles, deeply virtual Compton scattering, and hadron production in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes and skewed parton distributions.
A short review of the theory of hard exclusive processes
Wallon, Samuel
2011-01-01
We first present an introduction to the theory of hard exclusive processes. We then illustrate this theory by a few selected examples. The last part is devoted to the most recent developments in the asymptotical energy limit.
Central Exclusive Production in Proton-Proton Collisions with the STAR Experiment at RHIC
Guryn, Włodek
2016-07-01
We shall describe the physics program with tagged forward protons, focusing on Central Exclusive Production in polarized proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC), with the STAR detector at √s = 200 GeV. Preliminary results in CEP of two oppositely charged pions and kaons produced in the processes pp → ppπ+π- and pp → ppK+K- shall be presented. Those Double Pomeron Exchange (DPE) processes, allow the final states to be dominated by gluonic exchanges. Silicon strip detectors placed in Roman Pots were used for measuring forward protons. The preliminary results are based on the measurement of the recoil system of charged particles in the STAR experiment's Time Projection Chamber (TPC). Ionization energy loss, dE/dx, of charged particles was used for particle identification (PID).
Central exclusive production as a probe of the gluonic component of the eta' and eta mesons
Harland-Lang, L A; Ryskin, M G; Stirling, W J
2013-01-01
Currently, the long-standing issue concerning the size of the gluonic content of the eta' and eta mesons remains unsettled. With this in mind we consider the central exclusive production (CEP) of eta', eta meson pairs in the perturbative regime, applying the Durham pQCD-based model of CEP and the `hard exclusive' formalism to evaluate the meson production subprocess. We calculate for the first time the relevant parton-level processes gg --> qqbar gg and gg --> gggg, where the final-state gg and qqbar pairs form a pseudoscalar flavour-singlet state. We observe that these amplitudes display some non-trivial and interesting theoretical properties, and we comment on how this can be understood in a MHV framework. Finally, we present a phenomenological study, and show that the cross sections for the CEP of eta', eta meson pairs are strongly sensitive to the size of the gluon content of these mesons. The observation of these processes could therefore provide important and novel insight into this problem.
Central exclusive production as a probe of the gluonic component of the η' and η mesons
Harland-Lang, L. A.; Khoze, V. A.; Ryskin, M. G.; Stirling, W. J.
2013-05-01
Currently, the long-standing issue concerning the size of the gluonic content of the η' and η mesons remains unsettled. With this in mind we consider the central exclusive production (CEP) of η', η meson pairs in the perturbative regime, applying the Durham pQCD-based model of CEP and the `hard exclusive' formalism to evaluate the meson production subprocess. We calculate for the first time the relevant leading order parton-level processes gg to qoverline{q}gg and gg→ gggg, where the final-state gg and qoverline{q} pairs form a pseudoscalar flavour-singlet state. We observe that these amplitudes display some non-trivial and interesting theoretical properties, and we comment on their origin. Finally, we present a phenomenological study, and show that the cross sections for the CEP of η', η meson pairs are strongly sensitive to the size of the gluon content of these mesons. The observation of these processes could therefore provide important and novel insight into this problem.
Quark Orbital Angular Momentum and Exclusive Processes at HERMES
A first attempt for a model-dependent extraction of the orbital angular momentum of quarks in the nucleon has been made, based on HERMES data on exclusive processes and their description in terms of generalized parton distributions. An overview of the HERMES data on hard exclusive electroproduction of real photons (Deeply-Virtual Compton Scattering) and mesons is given, focusing on the measurements relevant to the extraction of quark orbital angular momentum
Quark Orbital Angular Momentum and Exclusive Processes at HERMES
Ellinghaus, F.
2006-11-01
A first attempt for a model-dependent extraction of the orbital angular momentum of quarks in the nucleon has been made, based on HERMES data on exclusive processes and their description in terms of generalized parton distributions. An overview of the HERMES data on hard exclusive electroproduction of real photons (Deeply-Virtual Compton Scattering) and mesons is given, focusing on the measurements relevant to the extraction of quark orbital angular momentum.
Trigger strategies for central exclusive $H \\to b\\overline{b}$ studies with the AFP detector
Brown, G J A; Kupco, A; Pilkington, A; Tasevsky, M
2009-01-01
The ATLAS Forward Proton (AFP) upgrade proposes to install proton detectors at 220 m and 420 m either side of the ATLAS interaction point, turning the LHC into a giant magnetic spectrometer. The physics motivation for this upgrade focuses on ﬁnal states in which the colliding protons remain intact, allowing a full reconstruction of the event, even in the forward region. One such process is the production of the Higgs boson in the central exclusive channel and tagging the outgoing protons allows the possible extraction of the Higgs quantum numbers, mass and couplings regardless of the decay channel. Studying this exclusive production channel for the presently favoured low Higgs mass depends on the possibility of efﬁciently triggering, up to the highest luminosities, on a pair of relatively soft jets coming from the decay of b quarks or τ leptons. As jet triggers will inevitably be heavily pre-scaled, even at modest luminosities, it is essential to make a coincidence betweeen information from the tagging d...
Nonperturbative and spin effects in the central exclusive production of tensor \\chi_c(2^+) meson
Pasechnik, R S; Teryaev, O V
2009-01-01
We discuss central exclusive production (CEP) of the tensor $\\chi_c(2^{+})$ meson in proton-(anti)proton collisions at Tevatron, RHIC and LHC energies. The amplitude for the process is derived within the $k_t$-factorisation approach. Differential and total cross sections are calculated for several unintegrated gluon distributions (UGDFs). We compare exclusive production of all charmonium states $\\chi_c(0^+), \\chi_c(1^+)$ and $\\chi_c(2^+)$. Good description of the recent Tevatron data is achieved both with Martin-Ryskin phenomenological UGDF and UGDF based on unified BFKL-DGLAP approach. Unlike for Higgs production, the main contribution to the diffractive amplitude of heavy quarkonia comes from nonperturbative region of gluon transverse momenta $Q_{\\perp}<1 \\GeV$. At $y \\approx$ 0, we predict the contribution of $\\chi_c(1^+,2^+)$ to the $J/\\Psi + \\gamma$ channel to be larger than that of the $\\chi_c(0^+)$ one. This is partially due to a significant contribution from lower polarization states $\\lambda=0$ fo...
Scaling Limits of a Tagged Particle in the Exclusion Process with Variable Diffusion Coefficient
Gonçalves, Patrícia; Jara, Milton
2008-09-01
We prove a law of large numbers and a central limit theorem for a tagged particle in a symmetric simple exclusion process in ℤ with variable diffusion coefficient. The scaling limits are obtained from a similar result for the current through -1/2 for a zero-range process with bond disorder. For the CLT, we prove convergence to a fractional Brownian motion of Hurst exponent 1/4.
Review of central exclusive production of the Higgs boson beyond the Standard Model
Taševský, Marek
2014-01-01
Roč. 29, č. 28 (2014), "1446012-1"-"1446012-21". ISSN 0217-751X R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : LHC * Higgs boson * central exclusive production * beyond Standard Model * forward detectors Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.699, year: 2014
The Processes of Inclusion and Exclusion in Physical Education
Jensen, Mette Munk; Agergaard, Sine
2015-01-01
Existing research on inclusion and exclusion processes in physical education (PE) has particularly focused on exclusion from PE as something being done to students and attributed to specific social categories such as (female) gender, (low) physical skills or (minority) ethnic background. This...... article aims to develop a social-relational perspective on inclusion and exclusion processes defined as students’ participation or non-participation in PE interpreted as a community of practice. In so doing, the article examines how students’ experiences of participation and non-participation in PE are...... influenced by complex interactions within the group of students and in negotiations with teachers about the values and practices of PE. The article is based on an embedded single-case study carried out over the course of 6 months through weekly observations of PE classes in a multi-ethnic school, as well as...
When push comes to shove: Exclusion processes with nonlocal consequences
Almet, Axel A.; Pan, Michael; Hughes, Barry D.; Landman, Kerry A.
2015-11-01
Stochastic agent-based models are useful for modelling collective movement of biological cells. Lattice-based random walk models of interacting agents where each site can be occupied by at most one agent are called simple exclusion processes. An alternative motility mechanism to simple exclusion is formulated, in which agents are granted more freedom to move under the compromise that interactions are no longer necessarily local. This mechanism is termed shoving. A nonlinear diffusion equation is derived for a single population of shoving agents using mean-field continuum approximations. A continuum model is also derived for a multispecies problem with interacting subpopulations, which either obey the shoving rules or the simple exclusion rules. Numerical solutions of the derived partial differential equations compare well with averaged simulation results for both the single species and multispecies processes in two dimensions, while some issues arise in one dimension for the multispecies case.
Dispersion relations and subtractions in hard exclusive processes
Anikin, I V
2007-01-01
We study analytical properties of the hard exclusive processes amplitudes. We found that QCD factorization for deeply virtual Compton scattering and hard exclusive vector meson production results in the subtracted dispersion relation with the subtraction constant determined by the Polyakov-Weiss $D$-term. The relation of this constant to the fixed pole contribution found by Brodsky, Close and Gunion and defined by parton distributions is proved, while its manifestation is spoiled by the small $x$ divergence. The continuation to the real photons limit is considered and the numerical correspondence between lattice simulations of $D$-term and low energy Thomson amplitude is found.
Exclusive processes with a leading neutron in $ep$ collisions
Goncalves, V P; Spiering, D
2015-01-01
In this paper we extend the color dipole formalism to the study of exclusive processes associated with a leading neutron in $ep$ collisions at high energies. The exclusive $\\rho$, $\\phi$ and $J/\\Psi$ production, as well as the Deeply Virtual Compton Scattering, are analysed assuming a diffractive interaction between the color dipole and the pion emitted by the incident proton. We compare our predictions with the HERA data on $\\rho$ production and estimate the magnitude of the absorption corrections. We show that the color dipole formalism is able to describe the current data. Finally, we present our estimate for the exclusive cross sections which can be studied at HERA and in future electron-proton colliders.
Inclusive and Exclusive Compton Processes in Quantum Chromodynamics
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.
Recent progress in some exclusive and semi-exclusive processes in proton-proton collisions
Szczurek, Antoni; Luszczak, Marta; Schafer, Wolfgang
2015-01-01
We present the main results of our recent analyses of exclusive production of vector charmonia ($J/\\psi$ and $\\psi'$) in $k_t$-factorization approach and for $\\gamma \\gamma$ production of charged dilepton pairs in exclusive and semiinclusive processes in a new approach, similar in spirit to $k_t$-factorization. The results for charmonia are compared with recent results of the LHCb collaboration. We include some helicity flip contributions and quantify the effect of absorption correction. The effect of $c \\bar c$ wave function is illustrated. We present uncertainties related to $F_2$ structure function which are the main ingredient of the approach. Our results are compared with recent CMS data for dilepton production with lepton isolation cuts imposed.
Why the Central Dogma: on the nature of the great biological exclusion principle.
Koonin, Eugene V
2015-01-01
The Central Dogma of molecular biology posits that transfer of information from proteins back to nucleic acids does not occur in biological systems. I argue that the impossibility of reverse translation is indeed a major, physical exclusion principle that emerges due to the transition from the digital information carriers, nucleic acids, to analog information carriers, proteins, which involves irreversible suppression of the digital information. PMID:26377089
Exclusive Central Meson Production in Proton Antiproton Collisions at the Tevatron
Swiech Artur
2012-12-01
Full Text Available It has been known since the days of the Intersecting Storage Rings, ISR, at CERN, that one can have pp interactions with more than one pomeron, ℙ, exchanged, known as double pomeron exchange. Exclusive hadronic systems, produced by double pomeron exchange, DℙE, have the potential of opening a rich new window on hadron spectroscopy and the diffraction mechanism. We have studied events of the type p + p¯ $ar p$ → p + X + p¯ $ar p$ where X is a hadron pair (mostly π+π− at √s = 900 GeV and 1960 GeV in the Collider Detector at Fermilab (CDF. The hadron pair is central, y ≈ 0, and between two rapidity gaps Δy ≈ 4. The dominant process is double pomeron exchange, DℙE, with restrictions on the quantum numbers of X: Q = S = 0, C = +1, J = 0 or 2. The mass spectra, with about 300K candidate events assumed to be π+π−, shows strong resonant structures attributed to f0 and f2 states. We give the ratio of cross sections at √s = 900 GeV and 1960 GeV, and compare with Regge expectations.
Progress in the theory of hard exclusive processes
Recent progresses in the theory of hard exclusive processes are reviewed. The hard scattering mechanism and the factorization of perturbative QCD amplitudes from wave-function-like quantities is now well understood. The effects of soft gluon radiation are controlled through Sudakov form factors which protect observables from dangerous end-point contributions. The phenomenology of this mature framework is eagerly waiting for precise experimental data in a domain where transfers are O(10 GeV2). (author). 11 refs., 2 figs
Dispersion relations and subtractions in hard exclusive processes
We study analytical properties of the hard exclusive process amplitudes. We found that QCD factorization for deeply virtual Compton scattering and hard exclusive vector meson production results in the subtracted dispersion relation with the subtraction constant determined by the Polyakov-Weiss D-term. The relation of this constant to the fixed pole contribution found by Brodsky, Close, and Gunion and defined by parton distributions is studied and proved for momentum transfers exceeding the typical hadronic scale. The continuation to the real photon limit is considered, and the numerical correspondence between lattice simulations of the D-term and low energy Thomson amplitude is found. For sufficiently large t the subtraction may be expressed in a form similar to that suggested earlier for real Compton scattering
The AdS/QCD Correspondence and Exclusive Processes
Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; de Teramond, Guy F.; /Costa Rica U.; Deur, Alexandre; /Jefferson Lab
2010-08-25
The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model modified by a positive-sign dilaton metric leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and a Regge spectrum of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n for both mesons and baryons. One also predicts the form of the non-perturbative effective coupling {alpha}{sub s}{sup AdS}(q) and its {beta}-function which agrees with the effective coupling {alpha}{sub ga} extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable {zeta}, allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply virtual Compton scattering, exclusive heavy hadron decays and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for hard exclusive reactions at high momentum transfer. As specific examples we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.
The ADS/QCD correspondence and exclusive processes
The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model, modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and meson and baryon Regge spectra of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n. One also predicts the form of the non-perturbative effective coupling alpha AdS/s (Q) and its Beta-function which agrees with the effective coupling alphag1 extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable zeta, allows one to compute the analytic form of the frame-independent light-front wave functions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply-virtual Compton scattering, exclusive heavy hadron decays, and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for exclusive reactions at high momentum transfer. As specific examples, we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.
The AdS/QCD Correspondence and Exclusive Processes
The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model modified by a positive-sign dilaton metric leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and a Regge spectrum of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n for both mesons and baryons. One also predicts the form of the non-perturbative effective coupling αsAdS(q) and its β-function which agrees with the effective coupling αga extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable ζ, allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply virtual Compton scattering, exclusive heavy hadron decays and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for hard exclusive reactions at high momentum transfer. As specific examples we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.
The Ads/qcd Correspondence and Exclusive Processes
Brodsky, Stanley J.; de Téramond, Guy F.; Deur, Alexandre
2011-02-01
The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model, modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and meson and baryon Regge spectra of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n. One also predicts the form of the non-perturbative effective coupling α sAdS (Q) and its β-function which agrees with the effective coupling αg1 extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable ζ, allows one to compute the analytic form of the frame-independent light-front wave functions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply-virtual Compton scattering, exclusive heavy hadron decays, and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for exclusive reactions at high momentum transfer. As specific examples, we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.
Analytic Properties of DPE Amplitudes or Collinear Factorisation for Central Exclusive Production
Teryaev, O V
2010-01-01
Analytic and crossing properties of amplitudes of the central exclusive production (CEP) are considered using the formalism of collinear Generalised Parton Distributions (GPDs). The analytic continuation from unphysical region is considered which leads to the finite expression. The natural interpretation of the emerging cuts corresponds to double spectral density in overlapping channel due to the instability of produced particle and inapplicability of Steinmann relations. The relations of CEP amplitudes to the exclusive decay rates are discussed. The direct calculation in physical region results in violation of factorisation similar to the discussed recently for pion transition and electromagnetic form-factors. The similarity between Feynman mechanism for form-factor and Durham model is pointed out.
Central Limit Theorem for Nonlinear Hawkes Processes
Zhu, Lingjiong
2012-01-01
Hawkes process is a self-exciting point process with clustering effect whose jump rate depends on its entire past history. It has wide applications in neuroscience, finance and many other fields. Linear Hawkes process has an immigration-birth representation and can be computed more or less explicitly. It has been extensively studied in the past and the limit theorems are well understood. On the contrary, nonlinear Hawkes process lacks the immigration-birth representation and is much harder to analyze. In this paper, we obtain a functional central limit theorem for nonlinear Hawkes process.
Quantum Central Processing Unit and Quantum Algorithm
王安民
2002-01-01
Based on a scalable and universal quantum network, quantum central processing unit, proposed in our previous paper [Chin. Phys. Left. 18 (2001)166], the whole quantum network for the known quantum algorithms,including quantum Fourier transformation, Shor's algorithm and Grover's algorithm, is obtained in a unitied way.
From generalized directed animals to the asymmetric simple exclusion process
Haug, Nils; Nechaev, Sergei; Tamm, Mikhail
2012-01-01
Using the generalized normally ordered form of words in a locally-free group of $n$ generators, we show that in the limit $n\\to\\infty$, the partition function of weighted directed lattice animals on a semi-infinite strip coincides with the partition function of stationary configurations of the asymmetric simple exclusion process (ASEP) with arbitrary entry/escape rates through open boundaries. We relate the features of the ASEP in the different regimes of the phase diagram to the geometric fe...
Hard exclusive processes in the one - and two - nucleon systems
A description of hard exclusive processes in the one-and two-nucleon system is attempted in the quark parton approach. The discussion deals with the large momentum transfer electromagnetic form factors of nucleon and deuteron as well as the wide angle, high energy nucleon-nucleon scattering differential cross-section and spin correlation parameters. We review the perturbative Quantum Chromodynamics approach initiated in recent works. The limitations of the approach are emphasized to motivate the consideration of a phenomenological approach. The core parton model introduced some time ago is discussed in both its spinless and spin versions. The predictions are compared with measurements
Open two-species exclusion processes with integrable boundaries
We give a complete classification of integrable Markovian boundary conditions for the asymmetric simple exclusion process with two species (or classes) of particles. Some of these boundary conditions lead to non-vanishing particle currents for each species. We explain how the stationary state of all these models can be expressed in a matrix product form, starting from two key components, the Zamolodchikov–Faddeev and Ghoshal–Zamolodchikov relations. This statement is illustrated by studying in detail a specific example, for which the matrix ansatz (involving nine generators) is explicitly constructed and physical observables (such as currents, densities) calculated. (paper)
Asymmetric exclusion processes on a closed network with bottlenecks
We study the generic nonequilibrium steady states in asymmetric exclusion processes on a closed network with bottlenecks. To this end we propose and study closed simple networks with multiple-connected non-identical junctions. Depending upon the parameters that define the network junctions and the particle number density, the models display phase transitions with both static and moving density inhomogeneities. The currents in the models can be tuned by the junction parameters. Our models highlight how extended and point defects may affect the density profiles in a closed directed network. Phenomenological implications of our results are discussed. (paper)
A study of exclusive central hadron production at the ISR as a search for gluonium states
We present first results from a study of the exclusive reaction pp->pπ+π-p at √s=63 GeV with π+ and π- produced in the central region. This reaction has been suggested as a method of searching for gluonium states. The π+π- mass distribution shows rapid order of magnitude decreases in cross section at both 1000 MeV/c2 and 1500 MeV/c2. Further structure is observed above 2000 MeV/c2. (orig.)
Spatiotemporally Complete Condensation in a Non-Poissonian Exclusion Process
Concannon, Robert J.; Blythe, Richard A.
2014-02-01
We investigate a non-Poissonian version of the asymmetric simple exclusion process, motivated by the observation that coarse graining the interactions between particles in complex systems generically leads to a stochastic process with a non-Markovian (history-dependent) character. We characterize a large family of one-dimensional hopping processes using a waiting-time distribution for individual particle hops. We find that when its variance is infinite, a real-space condensate forms that is complete in space (involves all particles) and time (exists at almost any given instant) in the thermodynamic limit. The mechanism for the onset and stability of the condensate is rather subtle and depends on the microscopic dynamics subsequent to a failed particle hop attempt.
Optimizing evacuation flow in a two-channel exclusion process
Galla, Tobias
2011-01-01
We use a basic setup of two coupled exclusion processes to model a stylised situation in evacuation dynamics, in which evacuees have to choose between two escape routes. The coupling between the two processes occurs through one common point at which particles are injected, the process can be controlled by directing incoming individuals into either of the two escape routes. Based on a mean-field approach we determine the phase behaviour of the model, and analytically compute optimal control strategies, maximising the total current through the system. Results are confirmed by numerical simulations. We also show that dynamic intervention, exploiting fluctuations about the mean-field stationary state, can lead to a further increase in total current.
Factorization of exclusive processes in perturbative quantum-chromodynamics
The work carried out in this thesis presents various theoretical and phenomenological studies of the exclusive production of longitudinally polarized neutral vector rho mesons in virtual photons collisions, within the framework of quantum-chromodynamics (QCD). The virtuality of the photons makes it possible to locate our approach in the perturbative area of the theory. The kinematical regimes considered allow the use of varied theoretical tools which reveal various properties of factorization of the scattering amplitude: two types of collinear factorization (at short distance) for this process are discussed in chapter 1, revealing - according to the polarization of the virtual photons and the kinematical limit considered- Generalized Distribution Amplitudes (GDA) or Transition Distribution Amplitudes (TDA), tools commonly used in the description of exclusive processes. We introduce into the Chapter 2 in a self-consistent way, the foundations of the BFKL (Balitskii, Fadin, Kuraev and Lipatov) formalism valid within the high energy limit (Regge limit) of QCD, for its phenomenological use detailed in Chapter 3: the scattering amplitude of the process is described in this formalism by exploiting the factorization in the two-dimensional transverse momentum space, or kT-factorization. We predict the value of the cross section of the process at Born order of the BFKL resummation and we discuss its possible observation at the future international linear collider (ILC). We consider also the differential cross sections of the process without momentum transfer with complete BFKL evolution at the order of the leading logarithms (Leading-Order) and also at the Next-to-Leading-Order to establish a fine test of this process with hard BFKL Pomeron exchange, observable at the future ILC. (author)
21 CFR 1305.24 - Central processing of orders.
2010-04-01
... order with all linked records on the central computer system. (b) A company that has central processing... or more registered locations and maintains a central processing computer system in which orders are... the company owns and operates....
Power spectra of a constrained totally asymmetric simple exclusion process
Cook, L. Jonathan; Zia, R. K. P.
2010-07-01
In nature, all biological systems function in a far-from-equilibrium state. Here, we study the process of translation in protein synthesis, using the totally asymmetric simple exclusion process (TASEP) as a model. In particular, we explore the effects of a finite supply of particles for the TASEP, as in a living cell with a finite pool of ribosomes. Specifically, we investigate the power spectrum associated with total occupancy, utilizing both Monte Carlo simulations and theoretical analysis. New features arise, such as large suppressions at low frequencies, due to the added constraint. A theory is formulated based on a Langevin approach with discrete space and time. With good agreement between the simulation and theory, we gain some insights into the effects of finite resources on the TASEP.
Strategy as Central and Peripheral Processes
Juul Andersen, Torben; Fredens, Kjeld
2012-01-01
Corporate entrepreneurship is deemed essential to uncover opportunities that shape the future strategic path and adapt the firm to environmental change (e.g., Covin and Miles, 1999; Wolcott and Lippitz, 2007). At the same time, rational central processes are important to execute strategic actions in a coordinated manner (e.g., Baum and Wally, 2003; Brews and Hunt, 1999; Goll and Rasheed, 1997). That is, the organization’s adaptive responses and dynamic capabilities are embedded...
Central exclusive production as a probe of the gluonic component of the {eta}' and {eta} mesons
Harland-Lang, L.A. [University of Durham, Department of Physics and Institute for Particle Physics Phenomenology, Durham (United Kingdom); Khoze, V.A. [University of Durham, Department of Physics and Institute for Particle Physics Phenomenology, Durham (United Kingdom); NRC Kurchatov Institute, Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation); Ryskin, M.G. [NRC Kurchatov Institute, Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation); Stirling, W.J. [University of Cambridge, Cavendish Laboratory, Cambridge (United Kingdom); Collaboration: The KRYSTHAL Collaboration
2013-05-15
Currently, the long-standing issue concerning the size of the gluonic content of the {eta}' and {eta} mesons remains unsettled. With this in mind we consider the central exclusive production (CEP) of {eta}', {eta} meson pairs in the perturbative regime, applying the Durham pQCD-based model of CEP and the 'hard exclusive' formalism to evaluate the meson production subprocess. We calculate for the first time the relevant leading order parton-level processes gg {yields}qqgg and gg{yields}gggg, where the final-state gg and qq pairs form a pseudoscalar flavour-singlet state. We observe that these amplitudes display some non-trivial and interesting theoretical properties, and we comment on their origin. Finally, we present a phenomenological study, and show that the cross sections for the CEP of {eta}', {eta} meson pairs are strongly sensitive to the size of the gluon content of these mesons. The observation of these processes could therefore provide important and novel insight into this problem. (orig.)
Adam, Michel; Assal, Sophie; Benicourt, Emmanuelle; Bonte, Pierre; Dorier Apprill, Élisabeth; Gillet, Marie; Giordano, Christian; Goedefroit, Sophie; Govoroff, Nicolas; Jacques-Jouvenot, Dominique; Karadimas, Dimitri; Lécrivain, Valérie; Lestage, Françoise; Lévi-Strauss, Claude; Pagès, Alexandre
2005-01-01
Sous le titre «Exclusions» sont réunis, dans ce numéro aux approches diverses, plusieurs sujets communs répondant à cet intitulé général : la pauvreté en milieu rural (France, Brésil, Madagascar) et le point de vue de la Banque mondiale sur cette question, les tensions ethniques et la territorialisation (Balkans, Mexique, Zambèze) enfin, l'importance d'une analyse anthropologique comparative pour comprendre la portée relative de la notion de productivité (C. Lévi-Strauss) et les logiques soci...
From generalized directed animals to the asymmetric simple exclusion process
Using the generalized normally ordered form of words in a locally-free group of n generators, we show that in the limit n → ∞, the partition function of weighted directed lattice animals on a semi-infinite strip coincides with the partition function of stationary configurations of the asymmetric simple exclusion process (ASEP) with arbitrary entry/escape rates through open boundaries. We relate the features of the ASEP in the different regimes of the phase diagram to the geometric features of the associated generalized directed animals by showing the results of numerical simulations. In particular, we show how the presence of shocks at the first order transition line translates into the directed animal picture. Using the evolution equation for generalized, weighted Lukasiewicz paths, we also provide a straightforward calculation of the known ASEP generating function. (paper)
From generalized directed animals to the asymmetric simple exclusion process
Haug, N.; Nechaev, S.; Tamm, M.
2014-10-01
Using the generalized normally ordered form of words in a locally-free group of n generators, we show that in the limit n → ∞, the partition function of weighted directed lattice animals on a semi-infinite strip coincides with the partition function of stationary configurations of the asymmetric simple exclusion process (ASEP) with arbitrary entry/escape rates through open boundaries. We relate the features of the ASEP in the different regimes of the phase diagram to the geometric features of the associated generalized directed animals by showing the results of numerical simulations. In particular, we show how the presence of shocks at the first order transition line translates into the directed animal picture. Using the evolution equation for generalized, weighted Lukasiewicz paths, we also provide a straightforward calculation of the known ASEP generating function.
Totally asymmetric exclusion processes with particles of arbitrary size
Lakatos, G
2003-01-01
The steady-state currents and densities of a one-dimensional totally asymmetric exclusion process (TASEP) with particles that occlude an integer number (d) of lattice sites are computed using various mean-field approximations and Monte Carlo simulations. TASEPs featuring particles of arbitrary size are relevant for modelling systems such as mRNA translation, vesicle locomotion along microtubules and protein sliding along DNA. We conjecture that the nonequilibrium steady-state properties separate into low-density, high-density, and maximal current phases similar to those of the standard (d = 1) TASEP. A simple mean-field approximation for steady-state particle currents and densities is found to be inaccurate. However, we find local equilibrium particle distributions derived from a discrete Tonks gas partition function yield apparently exact currents within the maximal current phase. For the boundary-limited phases, the equilibrium Tonks gas distribution cannot be used to predict currents, phase boundaries, or ...
Ecosystem process interactions between central Chilean habitats
Meredith Root-Bernstein
2015-01-01
Full Text Available Understanding ecosystem processes is vital for developing dynamic adaptive management of human-dominated landscapes. We focus on conservation and management of the central Chilean silvopastoral savanna habitat called “espinal”, which often occurs near matorral, a shrub habitat. Although matorral, espinal and native sclerophyllous forest are linked successionally, they are not jointly managed and conserved. Management goals in “espinal” include increasing woody cover, particularly of the dominant tree Acacia caven, improving herbaceous forage quality, and increasing soil fertility. We asked whether adjacent matorral areas contribute to espinal ecosystem processes related to the three main espinal management goals. We examined input and outcome ecosystem processes related to these goals in matorral and espinal with and without shrub understory. We found that matorral had the largest sets of inputs to ecosystem processes, and espinal with shrub understory had the largest sets of outcomes. Moreover, we found that these outcomes were broadly in the directions preferred by management goals. This supports our prediction that matorral acts as an ecosystem process bank for espinal. We recommend that management plans for landscape resilience consider espinal and matorral as a single landscape cover class that should be maintained as a dynamic mosaic. Joint management of espinal and matorral could create new management and policy opportunities.
Asymmetric exclusion process with a dynamic roadblock and open boundaries
Sahoo, Mamata; Klumpp, Stefan
2016-08-01
Motivated by complex transport processes occurring in nature, we study a totally asymmetric simple exclusion process (TASEP) with a dynamic ‘roadblock’ particle. The roadblock particle blocks the traffic of moving particles while bound to the lattice, but can stochastically unbind or switch off, thus enabling the traffic to pass. We use simulations to study the dependence of the particle flux on the on/off switching dynamics of the roadblock, which exhibits a surprisingly rich dynamic behaviour. In particular, unlike in other studied TASEP variants with defects, here we observe that the particle flux is affected by the roadblock even in the initiation-limited or low density phase if the roadblock dynamics is slow. Rapid switching off the roadblock results in the typical behaviour of a TASEP with a defect/pause with reduced maximal current, but no effect of the roadblock on the flux in the initiation-limited phase. Moreover, in an intermediate range of roadblock rates, the particle current is found to be system-size dependent.
Theoretical analysis and simulation for a facilitated asymmetric exclusion process
Hao, Qing-Yi; Chen, Zhe; Sun, Xiao-Yan; Liu, Bing-Bing; Wu, Chao-Yun
2016-08-01
Driven diffusive systems are important models in nonequilibrium state statistical mechanics. This paper studies an asymmetric exclusion process model with nearest rear neighbor interactions associated with energy. The exact flux expression of the model is obtained by a cluster mean-field method. Based on the flux expression, the properties of the fundamental diagram have been investigated in detail. To probe the energy's influence on the coarsening process of the system, Monte Carlo simulations are carried out to acquire the monotonic phase boundary in energy-density space. Above the phase boundary, the system is inhomogeneous and the normalized residence distribution p (s ) is nonmonotonically decreasing. Under the phase boundary, the system is homogeneous and p (s ) is monotonically decreasing. Further study comparatively shows that the system has turned into a microscopic inhomogeneous state from a homogeneous state before the system current arrives at maximum, if nearest rear neighbor interactions are strong. Our findings offer insights to deeply understand the dynamic features of nonequilibrium state systems.
Hypoxia in the central Arabian Gulf Exclusive Economic Zone (EEZ) of Qatar during summer season
Al-Ansari, Ebrahim M. A. S.; Rowe, G.; Abdel-Moati, M. A. R.; Yigiterhan, O.; Al-Maslamani, I.; Al-Yafei, M. A.; Al-Shaikh, I.; Upstill-Goddard, R.
2015-06-01
One of the most fascinating and unexpected discoveries during the Qatar University Marine Expeditions to the marine Exclusive Economic Zone (EEZ) of Qatar in 2000-2001, was the detection of a hypoxic water layer in the central region of the Arabian Gulf in waters deeper than 50 m. Hypoxia was defined as the region where the concentration of dissolved oxygen was less than 2 mg L-1. This article presents the discovery of hypoxia in the Arabian Gulf, based on samples collected (mainly during evening or night time) from vertical profiles along transects of the EEZ of Qatar and analyzed for physico-chemical properties, nutrients and chlorophyll-a. Hypoxia occurred in the summer months caused by an interaction between physical stratification of the water column that prevents oxygen replenishment, and biological respiration that consumes oxygen. Strong south-westerly winds (the SW monsoon) from June to September drive the relatively low-salinity nutrient-rich surface water from the Arabian Sea/Arabian Gulf (Sea of Oman) through the Strait of Hormuz into the central-Arabian Gulf, and this surface current penetration fertilizes the deep central-Arabian Gulf during the summer period. A strong seasonal pycnocline is formed between deeper waters at an ambient temperature of 20.9 °C and surface waters at 31.9 °C. This prevents the mixing of supersaturated O2 (>100-130%) water from the upper layer that would otherwise raise concentrations of dissolved oxygen below the thermocline, thus resulting in deep water hypoxia, i.e. dissolved oxygen levels of less than 0.86 ml L-1 at 17.3% saturation. These are the lowest values ever recorded for the Arabian Gulf. The calculated area of hypoxia is around 7220 square kilometers, and occurs in a layer about ≥15 m thick above the sea floor which extends toward the deep part of the Qatar Exclusive Economic Zone (EEZ). The biological consequences of this hypoxia on the sea floor are yet to be investigated.
Totally asymmetric exclusion processes with particles of arbitrary size
The steady-state currents and densities of a one-dimensional totally asymmetric exclusion process (TASEP) with particles that occlude an integer number (d) of lattice sites are computed using various mean-field approximations and Monte Carlo simulations. TASEPs featuring particles of arbitrary size are relevant for modelling systems such as mRNA translation, vesicle locomotion along microtubules and protein sliding along DNA. We conjecture that the nonequilibrium steady-state properties separate into low-density, high-density, and maximal current phases similar to those of the standard (d = 1) TASEP. A simple mean-field approximation for steady-state particle currents and densities is found to be inaccurate. However, we find local equilibrium particle distributions derived from a discrete Tonks gas partition function yield apparently exact currents within the maximal current phase. For the boundary-limited phases, the equilibrium Tonks gas distribution cannot be used to predict currents, phase boundaries, or the order of the phase transitions. However, we employ a refined mean-field approach to find apparently exact expressions for the steady-state currents, boundary densities, and phase diagrams of the d ≥ 1 TASEP. Extensive Monte Carlo simulations are performed to support our analytic, mean-field results
Totally asymmetric exclusion processes with particles of arbitrary size
Lakatos, Greg; Chou, Tom [Department of Biomathematics and Institute for Pure and Applied Mathematics, UCLA, Los Angeles, CA 90095 (United States)
2003-02-28
The steady-state currents and densities of a one-dimensional totally asymmetric exclusion process (TASEP) with particles that occlude an integer number (d) of lattice sites are computed using various mean-field approximations and Monte Carlo simulations. TASEPs featuring particles of arbitrary size are relevant for modelling systems such as mRNA translation, vesicle locomotion along microtubules and protein sliding along DNA. We conjecture that the nonequilibrium steady-state properties separate into low-density, high-density, and maximal current phases similar to those of the standard (d = 1) TASEP. A simple mean-field approximation for steady-state particle currents and densities is found to be inaccurate. However, we find local equilibrium particle distributions derived from a discrete Tonks gas partition function yield apparently exact currents within the maximal current phase. For the boundary-limited phases, the equilibrium Tonks gas distribution cannot be used to predict currents, phase boundaries, or the order of the phase transitions. However, we employ a refined mean-field approach to find apparently exact expressions for the steady-state currents, boundary densities, and phase diagrams of the d {>=} 1 TASEP. Extensive Monte Carlo simulations are performed to support our analytic, mean-field results.
QED Radiative Corrections in Processes of Exclusive Pion Electroproduction
Andrei Afanasev; I. Akushevich; Volker Burkert; K. Joo
2002-03-01
Formalism for radiative correction (RC) calculation in exclusive pion electroproduction on the proton is presented. A FORTRAN code EXCLURAD is developed for the RC procedure. The numerical analysis is done in the kinematics of current Jefferson Lab experiments.
Exclusive Central $\\pi^{+}\\pi^{-}$ Production in Proton Antiproton Collisions at the CDF
Zurek, Maria [Julich, Forschungszentrum
2015-01-01
Exclusive $\\pi^{=}\\pi^{-}$ production in proton-antiproton collisions at $\\sqrt{s}$ = 0.9 and 1.96 TeV in the Collider Detector at Fermilab has been measured. We select events with two particles with opposite charge in pseudorapidity region -1.3 < $\\eta$ < 1.3 with no other particles detected in -5.9 < $\\eta$ < 5.9. Particles are assumed to be pions. The $\\pi^{+}\\pi^{-}$system is required to have rapidity -1.0 < $y$ < 1.0. The data are expected to be dominated by the double pomeron exchange mechanism. Therefore, the quantum numbers of the central state are constrained. The data extend up to dipion mass M($\\pi^{+}\\pi^{-}$) = 5000 MeV/$c^2$. Resonance structures consistent with $f_0$ and $f_2$(1270) mesons are visible. The results are valuable for light hadron spectroscopy and for providing information about the nature of the pomeron in a region between non-perturbative and perturbative quantum chromodynamics
Measurement of diffractive and exclusive processes with the ATLAS detector
Gach, Grzegorz
2016-07-01
The ATLAS Collaboration has carried out a study of diffractive dijet production in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the LHC. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region with high diffractive contribution. Prospects for exclusive jet production studies with the forward proton tagging capability of the AFP sub-detector of ATLAS are also discussed. First results based on data taken jointly with the ATLAS and the LHCf detectors in a p+Pb run will also be shown. In addition, the measurement of the cross-section for the exclusive production of di-lepton pairs in pp collisions at √s = 7 TeV is discussed.
Measurement of diffractive and exclusive processes with the ATLAS detector
Gach Grzegorz
2016-01-01
Full Text Available The ATLAS Collaboration has carried out a study of diffractive dijet production in proton–proton collisions at a centre-of-mass energy of √s = 7 TeV at the LHC. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region with high diffractive contribution. Prospects for exclusive jet production studies with the forward proton tagging capability of the AFP sub-detector of ATLAS are also discussed. First results based on data taken jointly with the ATLAS and the LHCf detectors in a p+Pb run will also be shown. In addition, the measurement of the cross-section for the exclusive production of di-lepton pairs in pp collisions at √s = 7 TeV is discussed.
Measurement of diffractive and exclusive processes with the ATLAS detector
Gach, Grzegorz; The ATLAS collaboration
2015-01-01
The ATLAS collaboration has carried out a study diffractive dijet production at 7 TeV pp collisions at the LHC, i.e. events with a hadronic system containing at least two jets in addition to a large region of pseudorapidity devoid of hadronic activity. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region with high diffractive contribution. Prospects for exclusive jet production studies with the forward proton tagging capability of the AFP sub-detector of ATLAS will be discussed. A first look at data taken jointly with the ATLAS and LHCf detectors in a p+Pb run will also be shown. In addition the measurement of the exclusive $\\gamma+\\gamma \\rightarrow ll$ production cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV has been carried out.
FRACTIONAL FICK'S LAW FOR THE BOUNDARY DRIVEN EXCLUSION PROCESS WITH LONG JUMPS
Bernardin, Cédric; Oviedo Jimenez, Byron
2016-01-01
A fractional Fick's law and fractional hydrostatics for the one dimensional exclusion process with long jumps in contact with infinite reservoirs at different densities on the left and on the right are derived.
Exclusive processes at JLab at 6 GeV
Kim, Andrey [Univ. of Connecticut, Storrs, CT (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2015-01-01
Deeply virtual exclusive reactions provide a unique opportunity to probe the complex internal structure of the nucleon. They allow to access information about the correlations between parton transverse spatial and longitudinal momentum distributions from experimental observables. Dedicated experiments to study Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP) have been carried out at Jefferson Lab using continuous electron beam with energies up to 6 GeV. Unpolarized cross sections, beam, target and double spin asymmetries have been measured for DVCS as well as for π^{0} exclusive electroproduction. The data from Hall B provide a wide kinematic coverage with Q^{2}=1-4.5 GeV^{2}, x_{B}=0.1-0.5, and -t up to 2 GeV^{2}. Hall A data have limited kinematic range partially overlapping with Hall B kinematics but provide a high accuracy measurements. Scaling tests of the DVCS cross sections provide solid evidence of twist-2 dominance, which makes chiral-even GPDs accessible even at modest Q^{2}. We will discuss the interpretation of these data in terms of Generalized Parton Distributions (GPDs) model. Successful description of the recent CLAS π^{0} exclusive production data within the framework of the GPD-based model provides a unique opportunity to access the chiral-odd GPDs.
Exclusive processes at JLab at 6 GeV
Deeply virtual exclusive reactions provide a unique opportunity to probe the complex internal structure of the nucleon. They allow to access information about the correlations between parton transverse spatial and longitudinal momentum distributions from experimental observables. Dedicated experiments to study Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP) have been carried out at Jefferson Lab using continuous electron beam with energies up to 6 GeV. Unpolarized cross sections, beam, target and double spin asymmetries have been measured for DVCS as well as for π0 exclusive electroproduction. The data from Hall B provide a wide kinematic coverage with Q2=1-4.5 GeV2, xB=0.1-0.5, and -t up to 2 GeV2. Hall A data have limited kinematic range partially overlapping with Hall B kinematics but provide a high accuracy measurements. Scaling tests of the DVCS cross sections provide solid evidence of twist-2 dominance, which makes chiral-even GPDs accessible even at modest Q2. We will discuss the interpretation of these data in terms of Generalized Parton Distributions (GPDs) model. Successful description of the recent CLAS π0 exclusive production data within the framework of the GPD-based model provides a unique opportunity to access the chiral-odd GPDs.
Exclusive processes at JLab at 6 GeV
Kim Andrey
2015-01-01
Full Text Available Deeply virtual exclusive reactions provide a unique opportunity to probe the complex internal structure of the nucleon. They allow to access information about the correlations between parton transverse spatial and longitudinal momentum distributions from experimental observables. Dedicated experiments to study Deeply Virtual Compton Scattering (DVCS and Deeply Virtual Meson Production (DVMP have been carried out at Jefferson Lab using continuous electron beam with energies up to 6 GeV. Unpolarized cross sections, beam, target and double spin asymmetries have been measured for DVCS as well as for π0 exclusive electroproduction. The data from Hall B provide a wide kinematic coverage with Q2=1-4.5 GeV2, xB=0.1-0.5, and −t up to 2 GeV2. Hall A data have limited kinematic range partially overlapping with Hall B kinematics but provide a high accuracy measurements. Scaling tests of the DVCS cross sections provide solid evidence of twist-2 dominance, which makes chiral-even GPDs accessible even at modest Q2. We will discuss the interpretation of these data in terms of Generalized Parton Distributions (GPDs model. Successful description of the recent CLAS π0 exclusive production data within the framework of the GPD-based model provides a unique opportunity to access the chiral-odd GPDs.
Exclusive diffractive processes at HERA within the dipole picture
We present a simultaneous analysis, within an impact parameter dependent saturated dipole model, of exclusive diffractive vector meson (J/ψ, φ and ρ) production, deeply virtual Compton scattering and the total γ*p cross section data measured at HERA. Various cross sections measured as a function of the kinematic variables Q2, W and t are well described, with little sensitivity to the details of the vector meson wave functions. We determine the properties of the gluon density in the proton in both longitudinal and transverse dimensions, including the impact parameter dependent saturation scale. The overall success of the description indicates universality of the emerging gluon distribution and proton shape. (orig.)
Deeply Virtual Exclusive Processes and Generalized Parton Distributions
,
2011-06-01
The goal of the comprehensive program in Deeply Virtual Exclusive Scattering at Jefferson Laboratory is to create transverse spatial images of quarks and gluons as a function of their longitudinal momentum fraction in the proton, the neutron, and in nuclei. These functions are the Generalized Parton Distributions (GPDs) of the target nucleus. Cross section measurements of the Deeply Virtual Compton Scattering (DVCS) reaction ep {yields} ep{gamma} in Hall A support the QCD factorization of the scattering amplitude for Q^2 {>=} 2 GeV^2. Quasi-free neutron-DVCS measurements on the Deuteron indicate sensitivity to the quark angular momentum sum rule. Fully exclusive H(e, e'p{gamma} ) measurements have been made in a wide kinematic range in CLAS with polarized beam, and with both unpolarized and longitudinally polarized targets. Existing models are qualitatively consistent with the JLab data, but there is a clear need for less constrained models. Deeply virtual vector meson production is studied in CLAS. The 12 GeV upgrade will be essential for for these channels. The {rho} and {omega} channels reactions offer the prospect of flavor sensitivity to the quark GPDs, while the {phi}-production channel is dominated by the gluon distribution.
Harland-Lang, L A; Sakurai, K; Stirling, W J
2011-01-01
We discuss how the mass of new physics particles involved in a pair of short decay chains leading to two invisible particles, for example slepton pair production, followed by the decay into two leptons and two neutralinos, may be measured in central exclusive production (CEP) with forward proton tagging. We show how the existing mass measurement strategies in CEP may be improved by making full use of the mass-shell constraints, and demonstrate that, with around 30 signal events, the masses of the slepton and neutralino can be measured with an accuracy of a few GeV.
Overview of Central Auditory Processing Deficits in Older Adults.
Atcherson, Samuel R; Nagaraj, Naveen K; Kennett, Sarah E W; Levisee, Meredith
2015-08-01
Although there are many reported age-related declines in the human body, the notion that a central auditory processing deficit exists in older adults has not always been clear. Hearing loss and both structural and functional central nervous system changes with advancing age are contributors to how we listen, hear, and process auditory information. Even older adults with normal or near normal hearing sensitivity may exhibit age-related central auditory processing deficits as measured behaviorally and/or electrophysiologically. The purpose of this article is to provide an overview of assessment and rehabilitative approaches for central auditory processing deficits in older adults. It is hoped that the outcome of the information presented here will help clinicians with older adult patients who do not exhibit the typical auditory processing behaviors exhibited by others at the same age and with comparable hearing sensitivity all in the absence of other health-related conditions. PMID:27516715
Centralized processing of contact-handled TRU waste feasibility analysis
This report presents work for the feasibility study of central processing of contact-handled TRU waste. Discussion of scenarios, transportation options, summary of cost estimates, and institutional issues are a few of the subjects discussed
Angelaki, D. E.; Dickman, J. D.
2000-01-01
Spatiotemporal convergence and two-dimensional (2-D) neural tuning have been proposed as a major neural mechanism in the signal processing of linear acceleration. To examine this hypothesis, we studied the firing properties of primary otolith afferents and central otolith neurons that respond exclusively to horizontal linear accelerations of the head (0.16-10 Hz) in alert rhesus monkeys. Unlike primary afferents, the majority of central otolith neurons exhibited 2-D spatial tuning to linear acceleration. As a result, central otolith dynamics vary as a function of movement direction. During movement along the maximum sensitivity direction, the dynamics of all central otolith neurons differed significantly from those observed for the primary afferent population. Specifically at low frequencies (neurons peaked in phase with linear velocity, in contrast to primary afferents that peaked in phase with linear acceleration. At least three different groups of central response dynamics were described according to the properties observed for motion along the maximum sensitivity direction. "High-pass" neurons exhibited increasing gains and phase values as a function of frequency. "Flat" neurons were characterized by relatively flat gains and constant phase lags (approximately 20-55 degrees ). A few neurons ("low-pass") were characterized by decreasing gain and phase as a function of frequency. The response dynamics of central otolith neurons suggest that the approximately 90 degrees phase lags observed at low frequencies are not the result of a neural integration but rather the effect of nonminimum phase behavior, which could arise at least partly through spatiotemporal convergence. Neither afferent nor central otolith neurons discriminated between gravitational and inertial components of linear acceleration. Thus response sensitivity was indistinguishable during 0.5-Hz pitch oscillations and fore-aft movements. The fact that otolith-only central neurons with "high
Production of mesons with any internal orbital angular momentum in exclusive hard processes
Ichola, A.; Houra-Yaou, L.; Kessler, P.; Parisi, J. [College de France, 75 - Paris (France). Lab. de Physique Corpusculaire
1994-12-31
In this paper we present an extension of the computation of exclusive hard processes to the production of (qq) mesons with any orbital angular momentum, as well as of (gg) mesons (``glueballs``). We explicitly compute two examples: tensor-meson par production and glueball plus pion production, both in {gamma} {gamma} collisions. (authors). 16 refs., 7 figs., 1 tab.
Sun, Xiaoyan; Xie, Yanbo; He, Zhiwei; Wang, Binghong
2011-07-01
This Letter investigates a totally asymmetric simple exclusion process (TASEP) with junctions in a one-dimensional transport system. Parallel update rules and periodic boundary condition are adopted. Two cases corresponding to different update rules are studied. The results show that the stationary states of system mainly depend on the selection behavior of particle at the bifurcation point.
Jiang, Rui; Hu, Mao-Bin; Wu, Qing-Song
2008-07-01
Lakatos [Phys. Rev. E 71, 011103 (2005)] have studied a totally asymmetric exclusion process that contains periodically varying movement rates. They have presented a cluster mean-field theory for the problem. We show that their cluster mean-field theory leads to redundant equations. We present a mean-field analysis in which there is no redundant equation.
Non-stationary probabilities for the asymmetric exclusion process on a ring
V B Priezzhev
2005-06-01
A solution of the master equation for a system of interacting particles for finite time and particle density is presented. By using a new form of the Bethe ansatz, the totally asymmetric exclusion process on a ring is solved for arbitrary initial conditions and time intervals.
Baumeister, Roy F; Twenge, Jean M; Nuss, Christopher K
2002-10-01
Three studies examined the effects of randomly assigned messages of social exclusion. In all 3 studies, significant and large decrements in intelligent thought (including IQ and Graduate Record Examination test performance) were found among people told they were likely to end up alone in life. The decline in cognitive performance was found in complex cognitive tasks such as effortful logic and reasoning; simple information processing remained intact despite the social exclusion. The effects were specific to social exclusion, as participants who received predictions of future nonsocial misfortunes (accidents and injuries) performed well on the cognitive tests. The cognitive impairments appeared to involve reductions in both speed (effort) and accuracy. The effect was not mediated by mood. PMID:12374437
Exclusive diffractive processes in electron-ion collisions
Toll, Tobias; Ullrich, Thomas
2012-01-01
We present a new technique to calculate the cross-section for diffractive vector meson production and DVCS in electron-ion collisions based on the dipole model. The measurement of these processes can provide valuable information on non-linear QCD phenomena, such as gluon saturation, and is the the only known way to gain insight into the spatial distribution of gluons in nuclei. We present predictions of differential cross-section distribution $d\\sigma/dQ^2$ and $d\\sigma/dt$ for $J/\\psi$ and $...
INTEGRATION PROCESSES IN CENTRAL ASIA. PROSPECTS FOR A COMMON MARKET
Rakhmatullina, Gulnur
2005-01-01
Globalization processes have a growing effect on the development of individual countries and the world economy, with the Central Asian states, among others, being drawn into their orbit. The advantages of globalization are realized precisely at the integration and regional levels. That is why it is so important today to implement the initiative launched by President Islam Karimov of Uzbekistan for creating a Central Asian Common Market (CACM). The idea is that this market should include Kazak...
Angelaki, D. E.; Dickman, J. D.
2000-01-01
Spatiotemporal convergence and two-dimensional (2-D) neural tuning have been proposed as a major neural mechanism in the signal processing of linear acceleration. To examine this hypothesis, we studied the firing properties of primary otolith afferents and central otolith neurons that respond exclusively to horizontal linear accelerations of the head (0.16-10 Hz) in alert rhesus monkeys. Unlike primary afferents, the majority of central otolith neurons exhibited 2-D spatial tuning to linear acceleration. As a result, central otolith dynamics vary as a function of movement direction. During movement along the maximum sensitivity direction, the dynamics of all central otolith neurons differed significantly from those observed for the primary afferent population. Specifically at low frequencies (frequency. "Flat" neurons were characterized by relatively flat gains and constant phase lags (approximately 20-55 degrees ). A few neurons ("low-pass") were characterized by decreasing gain and phase as a function of frequency. The response dynamics of central otolith neurons suggest that the approximately 90 degrees phase lags observed at low frequencies are not the result of a neural integration but rather the effect of nonminimum phase behavior, which could arise at least partly through spatiotemporal convergence. Neither afferent nor central otolith neurons discriminated between gravitational and inertial components of linear acceleration. Thus response sensitivity was indistinguishable during 0.5-Hz pitch oscillations and fore-aft movements. The fact that otolith-only central neurons with "high-pass" filter properties exhibit semicircular canal-like dynamics during head tilts might have important consequences for the conclusions of previous studies of sensory convergence and sensorimotor transformations in central vestibular neurons.
Gazeley, Louise
2012-01-01
Although a great deal of previous literature has explored the ways in which social class affects parental engagement in educational processes, there has been surprisingly little discussion of the way in which social class shapes the parent-professional interaction that occurs in school exclusion processes specifically. School exclusion processes…
Effective ergodicity breaking in an exclusion process with varying system length
Schultens, Christoph; Schadschneider, Andreas; Arita, Chikashi
2015-09-01
Stochastic processes of interacting particles in systems with varying length are relevant e.g. for several biological applications. We try to explore what kind of new physical effects one can expect in such systems. As an example, we extend the exclusive queueing process that can be viewed as a one-dimensional exclusion process with varying length, by introducing Langmuir kinetics. This process can be interpreted as an effective model for a queue that interacts with other queues by allowing incoming and leaving of customers in the bulk. We find surprising indications for breaking of ergodicity in a certain parameter regime, where the asymptotic growth behavior depends on the initial length. We show that a random walk with site-dependent hopping probabilities exhibits qualitatively the same behavior.
Processes of Inclusion and Exclusion in the Sphere of Prosumerism
Roberta Paltrinieri
2013-01-01
Full Text Available The term prosumer, first introduced by Toffler in the 1980s, has been developed by sociologists in response to Web 2.0 (the set of technologies that has transformed a predominantly static web into the collaborative medium initially envisaged by Tim Berners-Lee. The phenomena is now understood as a process involving the creation of meanings on the part of the consumer, who re-appropriates spaces that were dominated by institutionalized production, and this extends to the exploitation of consumer creativity on the production side. Recent consumption literature can be re-interpreted through the prosumer lens in order to understand whether prosumers are more creative or alienated in their activities. The peculiar typology of prosumption introduced by Web 2.0 leads us to analyze social capital as a key element in value creation, and to investigate its different online and offline forms. Our analysis then discusses the digital divide and critical consumerism as forms of empowerment impairment.
GASTOF: Ultra-fast ToF forward detector for exclusive processes at the LHC
Bonnet, L; Piotrzkowski, K; Rodeghiero, P
2007-01-01
GASTOF (Gas Time-of-Flight) detector is a Cherenkov detector proposed for very precise (10--20 ps) arrival time measurements of forward protons at some 420 m from the central detectors of CMS and ATLAS. Such an excellent time resolution will allow by z-by-timing technique for precise measurement of the z-coordinate of the event vertex in exclusive production at the LHC, when two colliding protons are scattered at very small angles. In the paper we present first GASTOF prototype, simulations of its performance as well as first tests using a cosmic muon telescope.
PROCESSES OF SOCIAL EXCLUSION OF HOMELESSNESS IN THE CITY OF BARCELONA
María Virginia Matulic Domandzic
2013-12-01
Full Text Available Processes of social exclusion of the homeless people in the city of Barcelona are addressed in thisarticle through three sections. First, an approximation to the processes of social exclusion present inEuropean societies is done, then look focuses on the conceptual dimension of homeless people andits root causes, to end with some conclusions on where the issues raised are synthesized as well asthe future challenges that are presented in this phenomenon. This article is part of the research workbeing done on the processes of social inclusion of homeless people in Barcelona. This research islinked to the Doctorate "Education and Society" at the University of Barcelona through the Departmentof Social Work and Social Services. The growing phenomenon of homelessness responds to macroprocessesthat have characterized the post-Fordist societies in recent decades where the fragility ofsupport networks and systems of social protection are crucial.
Effects of serotonin 2A/1A receptor stimulation on social exclusion processing.
Preller, Katrin H; Pokorny, Thomas; Hock, Andreas; Kraehenmann, Rainer; Stämpfli, Philipp; Seifritz, Erich; Scheidegger, Milan; Vollenweider, Franz X
2016-05-01
Social ties are crucial for physical and mental health. However, psychiatric patients frequently encounter social rejection. Moreover, an increased reactivity to social exclusion influences the development, progression, and treatment of various psychiatric disorders. Nevertheless, the neuromodulatory substrates of rejection experiences are largely unknown. The preferential serotonin (5-HT) 2A/1A receptor agonist, psilocybin (Psi), reduces the processing of negative stimuli, but whether 5-HT2A/1A receptor stimulation modulates the processing of negative social interactions remains unclear. Therefore, this double-blind, randomized, counterbalanced, cross-over study assessed the neural response to social exclusion after the acute administration of Psi (0.215 mg/kg) or placebo (Pla) in 21 healthy volunteers by using functional magnetic resonance imaging (fMRI) and resting-state magnetic resonance spectroscopy (MRS). Participants reported a reduced feeling of social exclusion after Psi vs. Pla administration, and the neural response to social exclusion was decreased in the dorsal anterior cingulate cortex (dACC) and the middle frontal gyrus, key regions for social pain processing. The reduced neural response in the dACC was significantly correlated with Psi-induced changes in self-processing and decreased aspartate (Asp) content. In conclusion, 5-HT2A/1A receptor stimulation with psilocybin seems to reduce social pain processing in association with changes in self-experience. These findings may be relevant to the normalization of negative social interaction processing in psychiatric disorders characterized by increased rejection sensitivity. The current results also emphasize the importance of 5-HT2A/1A receptor subtypes and the Asp system in the control of social functioning, and as prospective targets in the treatment of sociocognitive impairments in psychiatric illnesses. PMID:27091970
Insulating process for HT-7U central solenoid model coils
无
2003-01-01
The HT-7U superconducting Tokamak is a whole superconducting magnetically confined fusion device. The insulating system of its central solenoid coils is critical to its properties. In this paper the forming of the insulating system and the vacuum-pressure-impregnating (VPI) are introduced, and the whole insulating process is verified under the superconducting experiment condition.
Test practice and processes of in- and exclusion in school classes
Andreasen, Karen Egedal
Recently national mandatory standardized testing has been implemented in compulsory school in both Norway and Denmark. In Sweden the national school reform from emphasize such pedagogical practice. Assessment has profound impact on processes of marginalization and in- and exclusion in school (Mc......Dermott & Varenne, 1995). Such impact are depending on what can be understood as local test practice, referring to local discourses and ways of using test in specific school contexts. Based on results from a two year study of the implementation of national standardized testing in Denmark in three school classes...... and drawing on the theory of Etienne Wenger (1998) about communities of practice this paper will discuss the impact from testing on processes of in- and exclusion. The empirical study is ethnographically inspired and includes observations, interviews, documents etc. The analysis shows that even it is framed...
Pire, B
2009-01-01
QCD is the theory of strong interactions and non-perturbative methods have been developed to address the confinement property of QCD. Many experimental measurements probe the confining dynamics, and it is well-known that hard scattering processes allow the extraction of non perturbative hadronic matrix elements. To study exclusive hard processes, such as electromagnetic form factors and reactions like gamma* N -> gamma N', gamma* N -> pi N', gamma* gamma -> pi pi, antiproton proton ->gamma* pi in particular kinematics (named as generalized Bjorken regime), one introduces specific non-perturbative objects, namely generalized parton distributions (GPDs), distribution amplitudes (DA) and transition distribution amplitudes (TDA), which are Fourier transformed non-diagonal matrix elements of non-local operators on the light-cone. We review here a selected sample of exclusive amplitudes in which the quark and gluon content of hadrons is probed, and emphasize that much remains to be done to successfully compute thei...
Technical evaluation of proposed Ukrainian Central Radioactive Waste Processing Facility
This technical report is a comprehensive evaluation of the proposal by the Ukrainian State Committee on Nuclear Power Utilization to create a central facility for radioactive waste (not spent fuel) processing. The central facility is intended to process liquid and solid radioactive wastes generated from all of the Ukrainian nuclear power plants and the waste generated as a result of Chernobyl 1, 2 and 3 decommissioning efforts. In addition, this report provides general information on the quantity and total activity of radioactive waste in the 30-km Zone and the Sarcophagus from the Chernobyl accident. Processing options are described that may ultimately be used in the long-term disposal of selected 30-km Zone and Sarcophagus wastes. A detailed report on the issues concerning the construction of a Ukrainian Central Radioactive Waste Processing Facility (CRWPF) from the Ukrainian Scientific Research and Design institute for Industrial Technology was obtained and incorporated into this report. This report outlines various processing options, their associated costs and construction schedules, which can be applied to solving the operating and decommissioning radioactive waste management problems in Ukraine. The costs and schedules are best estimates based upon the most current US industry practice and vendor information. This report focuses primarily on the handling and processing of what is defined in the US as low-level radioactive wastes
Language and central temporal auditory processing in childhood epilepsies.
Boscariol, Mirela; Casali, Raquel L; Amaral, M Isabel R; Lunardi, Luciane L; Matas, Carla G; Collela-Santos, M Francisca; Guerreiro, Marilisa M
2015-12-01
Because of the relationship between rolandic, temporoparietal, and centrotemporal areas and language and auditory processing, the aim of this study was to investigate language and central temporal auditory processing of children with epilepsy (rolandic epilepsy and temporal lobe epilepsy) and compare these with those of children without epilepsy. Thirty-five children aged between eight and 14 years old were studied. Two groups of children participated in this study: a group with childhood epilepsy (n=19), and a control group without epilepsy or linguistic changes (n=16). There was a significant difference between the two groups, with the worst performance in children with epilepsy for the gaps-in-noise test, right ear (preceptive vocabulary (PPVT) (p<0.001) and phonological working memory (nonwords repetition task) tasks (p=0.001). We conclude that the impairment of central temporal auditory processing and language skills may be comorbidities in children with rolandic epilepsy and temporal lobe epilepsy. PMID:26580215
The Braess Paradox in a network of totally asymmetric exclusion processes
Bittihn, Stefan
2016-01-01
We study the Braess paradox in the transport network as originally proposed by Braess with totally asymmetric exclusion processes (TASEPs) on the edges. The Braess paradox describes the counterintuitive situation where adding an additional edge to a road network leads to a user optimum with higher traveltimes for all network users. Traveltimes on the TASEPs are nonlinear in the density and jammed states can occur due to the microscopic exclusion principle. Furthermore the individual edges influence each other. This leads to a much more realistic description of traffic-like transport on the network than in previously studied linear macroscopic mathematical models. Furthermore the stochastic dynamics allows to explore the effects of fluctuations on the network performance. We observe that for low densities the added edge leads to lower traveltimes. For slightly higher densities the Braess paradox in its classical sense occurs in a small density regime. In a large regime of intermediate densities strong fluctuat...
Melanie Bungert
Full Text Available There is a general agreement that physical pain serves as an alarm signal for the prevention of and reaction to physical harm. It has recently been hypothesized that "social pain," as induced by social rejection or abandonment, may rely on comparable, phylogenetically old brain structures. As plausible as this theory may sound, scientific evidence for this idea is sparse. This study therefore attempts to link both types of pain directly. We studied patients with borderline personality disorder (BPD because BPD is characterized by opposing alterations in physical and social pain; hyposensitivity to physical pain is associated with hypersensitivity to social pain, as indicated by an enhanced rejection sensitivity.Twenty unmedicated female BPD patients and 20 healthy participants (HC, matched for age and education played a virtual ball-tossing game (cyberball, with the conditions for exclusion, inclusion, and a control condition with predefined game rules. Each cyberball block was followed by a temperature stimulus (with a subjective pain intensity of 60% in half the cases. The cerebral responses were measured by functional magnetic resonance imaging. The Adult Rejection Sensitivity Questionnaire was used to assess rejection sensitivity.Higher temperature heat stimuli had to be applied to BPD patients relative to HCs to reach a comparable subjective experience of painfulness in both groups, which suggested a general hyposensitivity to pain in BPD patients. Social exclusion led to a subjectively reported hypersensitivity to physical pain in both groups that was accompanied by an enhanced activation in the anterior insula and the thalamus. In BPD, physical pain processing after exclusion was additionally linked to enhanced posterior insula activation. After inclusion, BPD patients showed reduced amygdala activation during pain in comparison with HC. In BPD patients, higher rejection sensitivity was associated with lower activation differences during
Caetano, Marco Antonio Leonel; Yoneyama, Takashi
2015-07-01
This work concerns the study of the effects felt by a network as a whole when a specific node is perturbed. Many real world systems can be described by network models in which the interactions of the various agents can be represented as an edge of a graph. With a graph model in hand, it is possible to evaluate the effect of deleting some of its edges on the architecture and values of nodes of the network. Eventually a node may end up isolated from the rest of the network and an interesting problem is to have a quantitative measure of the impact of such an event. For instance, in the field of finance, the network models are very popular and the proposed methodology allows to carry out "what if" tests in terms of weakening the links between the economic agents, represented as nodes. The two main concepts employed in the proposed methodology are (i) the vibrational IC-Information Centrality, which can provide a measure of the relative importance of a particular node in a network and (ii) autocatalytic networks that can indicate the evolutionary trends of the network. Although these concepts were originally proposed in the context of other fields of knowledge, they were also found to be useful in analyzing financial networks. In order to illustrate the applicability of the proposed methodology, a case of study using the actual data comprising stock market indices of 12 countries is presented.
Effects of sleep deprivation on central auditory processing
Liberalesso Paulo Breno; D’Andrea Karlin Fabianne; Cordeiro Mara L; Zeigelboim Bianca; Marques Jair; Jurkiewicz Ari
2012-01-01
AbstractBackgroundSleep deprivation is extremely common in contemporary society, and is considered to be a frequent cause of behavioral disorders, mood, alertness, and cognitive performance. Although the impacts of sleep deprivation have been studied extensively in various experimental paradigms, very few studies have addressed the impact of sleep deprivation on central auditory processing (CAP). Therefore, we examined the impact of sleep deprivation on CAP, for which there is sparse informat...
A Universal Quantum Network Quantum Central Processing Unit
WANG An-Min
2001-01-01
A new construction scheme of a universal quantum network which is compatible with the known quantum gate- assembly schemes is proposed. Our quantum network is standard, easy-assemble, reusable, scalable and even potentially programmable. Moreover, we can construct a whole quantum network to implement the generalquantum algorithm and quantum simulation procedure. In the above senses, it is a realization of the quantum central processing unit.
Central limit theorem for Fourier transform of stationary processes
Peligrad, Magda
2009-01-01
We consider asymptotic behavior of Fourier transforms of stationary ergodic sequences with finite second moments. We establish the central limit theorem (CLT) for almost all frequencies and also the annealed CLT. The theorems hold for all regular sequences. Our results shed new light on the foundation of spectral analysis and on the asymptotic distribution of periodogram, and it provides a nice blend of harmonic analysis, theory of stationary processes and theory of martingales.
Perceptual weights for loudness reflect central spectral processing
Joshi, Suyash Narendra; Jesteadt, Walt
2011-01-01
Weighting patterns for loudness obtained using the reverse correlation method are thought to reveal the relative contributions of different frequency regions to total loudness, the equivalent of specific loudness. Current models of loudness assume that specific loudness is determined by peripheral...... processes such as compression and masking. Here we test this hypothesis using 20-tone harmonic complexes (200Hz f0, 200 to 4000Hz, 250 ms, 65 dB/Component) added in opposite phase relationships (Schroeder positive and negative). Due to the varying degree of envelope modulations, these time-reversed harmonic...... processes and reflect a central frequency weighting template....
The concepts of exclusion, exemption and clearance have been established in international recommendations and, standards for radiation protection and the management of radioactive waste in recent years. The consistent application of these concepts has given rise to various problems in different spheres of use. This is particularly the case in the mining and minerals processing industries dealing with materials exhibiting elevated concentrations of naturally occurring radionuclides. This paper takes the South African mining industry as an example and highlights some of the issues that have arisen in applying these concepts within a regulatory control regime. (author)
Studies of semi-inclusive and hard exclusive processes at Jlab
The main goal of experiments proposed for the CLAS12 detector in conjunction with the 12-GeV CEBAF accelerator is the study of the nucleon through hard exclusive, semi-inclusive, and inclusive processes. This will provide new insights into nucleon dynamics at the elementary quark and gluon level. In this contribution we provide an overview of ongoing studies of the structure of nucleon in terms of quark and gluon degrees of freedom and future physics program planned with CLAS and CLAS12
Studying the neutron orbital structure by coherent hard exclusive processes off 3He
Hard exclusive processes, such as Deeply Virtual Compton Scattering (DVCS), allows to access generalized parton distributions (GPDs). By means of an Impulse Approximation (IA) calculation, it is shown here how, in the low momentum transfer region, the sum of the GPDs H and E, is dominated by the neutron contribution. Thanks to this property, 3He could open a new way to access the neutron structure information. In this work, a simple and efficient extraction procedure of the neutron GPDs, able to take into account the nuclear effects included in IA analysis, is proposed.
Cube Root Fluctuations for the Corner Growth Model Associated to the Exclusion Process
Balazs, Marton; Cator, Eric; Seppalainen, Timo
2006-01-01
We study the last-passage growth model on the planar integer lattice with exponential weights. With boundary conditions that represent the equilibrium exclusion process as seen from a particle right after its jump we prove that the variance of the last-passage time in a characteristic direction is of order $t^{2/3}$. With more general boundary conditions that include the rarefaction fan case we show that the last-passage time fluctuations are still of order $t^{1/3}$, and also that the transv...
Studies of semi-inclusive and hard exclusive processes at Jlab
Harutyun Avagyan
2008-06-19
The main goal of experiments proposed for the {\\tt CLAS12} detector in conjunction with the 12-GeV CEBAF accelerator is the study of the nucleon through hard exclusive, semi-inclusive, and inclusive processes. This will provide new insights into nucleon dynamics at the elementary quark and gluon level. In this contribution we provide an overview of ongoing studies of the structure of nucleon in terms of quark and gluon degrees of freedom and future physics program planned with CLAS and {\\tt CLAS12}.
Asymmetric Exclusion Process with Constrained Hopping and Parallel Dynamics at a Junction
Liu, Mingzhe; Tuo, Xianguo; Li, Zhe; Yang, Jianbo
In this article totally asymmetric simple exclusion process (TASEP) with constrained hopping and parallel dynamics at a junction is investigated using a mean-field approximation and Monte Carlo simulations. The constrained particle hopping probability r (r ≤ 1) at a junction may correspond to a delay caused by a driver choosing the right direction or a delay waiting for green traffic light in the real world. There are six stationary phases in the system, which can reflect free flow and congested traffic situations. Correlations at the junction point are investigated via simulations. It is observed that small r leads to stronger correlations. The theoretical results are agreement with computer simulations well.
Power Spectra of a Totally Asymmetric Simple Exclusion Process with Finite Resources
Cook, L. Jonathan; Zia, Royce K. P.
2010-03-01
In a cell, a mRNA has only a finite number of ribosomes to use during protein synthesis. We take this constraint into account in the modeling of translation by a totally asymmetric simple exclusion process (TASEP). Through Monte Carlo simulations and analytical methods, we study the power spectrum of the total particle occupancy of the TASEP. New features are found, such as a severe suppression at low frequencies. We formulate a theory based on a linearized Langevin equation with discrete space and time. With good agreement between the theoretical approach and the simulations, we gain some insight in how finite resources affect a TASEP.
Evaluation of the Central Hearing Process in Parkinson Patients
Santos, Rosane Sampaio
2011-04-01
Full Text Available Introduction: Parkinson disease (PD is a degenerating disease with a deceitful character, impairing the central nervous system and causing biological, psychological and social changes. It shows motor signs and symptoms characterized by trembling, postural instability, rigidity and bradykinesia. Objective: To evaluate the central hearing function in PD patients. Method: A descriptive, prospect and transversal study, in which 10 individuals diagnosed of PD named study group (SG and 10 normally hearing individuals named control group (CG were evaluated, age average of 63.8 and (SD 5.96. Both groups went through otorhinolaryngological and ordinary audiological evaluations, and dichotic test of alternate disyllables (SSW. Results: In the quantitative analysis, CG showed 80% normality on competitive right-ear hearing (RC and 60% on the competitive left-ear hearing (LC in comparison with the SG that presented 70% on RC and 40% on LC. In the qualitative analysis, the biggest percentage of errors was evident in the SG in the order effect. The results showed a difficulty in identifying a sound when there is another competitive sound and in the memory ability. Conclusion: A qualitative and quantitative difference was observed in the SSW test between the evaluated groups, although statistical data does not show significant differences. The importance to evaluate the central hearing process is emphasized when contributing to the procedures to be taken at the therapeutic follow-up.
Invalidation: a central process underlying maltreatment of women with disabilities.
Hassouneh-Phillips, Dena; McNeff, Elizabeth; Powers, Laurie; Curry, Mary Ann
2005-01-01
Recent qualitative studies indicate that maltreatment of women with disabilities by health care providers is a serious quality of care issue. To begin to address this problem, we conducted a secondary analysis of data derived from three qualitative studies of abuse of women with disabilities. Findings identified Invalidation as a central process underlying maltreatment. Invalidation was characterized by health care providers Taking Over care, Discounting, Objectifying, and Hurting women with disabilities during health care encounters. These findings highlight the need to educate health care providers about social and interpersonal aspects of disability and address the problem of Invalidation in health care settings. PMID:16048867
Lebiedowicz, Piotr; Szczurek, Antoni
2016-01-01
We consider central exclusive diffractive dipion production in the reactions $pp \\to pp \\pi^{+} \\pi^{-}$ and $p\\bar{p} \\to p\\bar{p} \\pi^{+} \\pi^{-}$ at high energies. We include the dipion continuum, the dominant scalar $f_{0}(500)$, $f_{0}(980)$, and tensor $f_{2}(1270)$ resonances decaying into the $\\pi^{+} \\pi^{-}$ pairs. The calculation is based on a tensor pomeron model and the amplitudes for the processes are formulated in terms of vertices respecting the standard crossing and charge-conjugation relations of Quantum Field Theory. The formulae for the dipion continuum and tensor meson production are given here for the first time. The theoretical results are compared with existing STAR, CDF, CMS experimental data and predictions for planned or being carried out experiments (ALICE, ATLAS) are presented. We show the influence of the experimental cuts on the integrated cross section and on various differential distributions for outgoing particles. Distributions in rapidities and transverse momenta of outgoin...
On the constituent counting rules for hard exclusive processes involving multiquark states
Guo, Feng-Kun; Wang, Wei
2016-01-01
At high energies, the cross section of a hard exclusive process at finite scattering angle falls off as a negative power of the center-of-mass energy $\\sqrt{s}$. If all involved quark-gluon compositions undergo hard momentum transfers, the scaling of the fall-off is determined by the underlying valence structures of the initial and final states, known as the constituent counting rules. It was argued in the literature that the counting rules are a powerful tool to determine the valence degrees of freedom inside multiquark states when applied to exclusive production processes. However, we demonstrate that for hadrons with hidden flavors the naive application of the constituent counting rules is problematic, since it is not mandatory for all components to participate the hard scattering at the scale $\\sqrt{s}$. The correct scaling rules can be obtained easily by using effective field theory. A few examples involving the $Z_c(3900)^\\pm$ and $X(3872)$ are discussed.
The asymmetric simple exclusion process with open boundaries, which is a very simple model of out-of-equilibrium statistical physics, is known to be integrable. In particular, its spectrum can be described in terms of Bethe roots. The large deviation function of the current can be obtained as well by diagonalizing a modified transition matrix, which is still integrable: the spectrum of this new matrix can also be described in terms of Bethe roots for special values of the parameters. However, due to the algebraic framework used to write the Bethe equations in previous works, the nature of the excitations and the full structure of the eigenvectors remained unknown. This paper explains why the eigenvectors of the modified transition matrix are physically relevant, gives an explicit expression for the eigenvectors and applies it to the study of atypical currents. It also shows how the coordinate Bethe ansatz developed for the excitations leads to a simple derivation of the Bethe equations and of the validity conditions of this ansatz. All the results obtained by de Gier and Essler are recovered and the approach gives a physical interpretation of the exceptional points. The overlap of this approach with other tools such as the matrix ansatz is also discussed. The method that is presented here may be not specific to the asymmetric exclusion process and may be applied to other models with open boundaries to find similar exceptional points
Comment on Gauge invariance and kT-factorization of exclusive processes
We point out mistakes made in the one-loop calculation of some diagrams for the process π γ* → γ in the preprint arXiv:0807.0296, and present correct results. Especially, we have difficulty to understand their argument that a highly off-shell gluon generates a light-cone (infrared) singularity. It is shown by means of the Ward identity that the gauge-dependent light-cone singularity found in arXiv:0807.0296 does not exist. It is then shown that a hard kernel derived in the kT factorization of exclusive processes is gauge invariant and free of the light-cone singularity. (orig.)
Corianò, C; Savkli, C; Coriano, Claudio; Li, Hsiang-nan; Savkli, Cetin
1998-01-01
Experiments at CEBAF will scan the intermediate-energy region of the QCD dynamics for the nucleon form factors and for Compton Scattering. These experiments will definitely clarify the role of resummed perturbation theory and of quark-hadron duality (QCD sum rules) in this regime. With this perspective in mind, we review the factorization theorem of perturbative QCD for exclusive processes at intermediate energy scales, which embodies the transverse degrees of freedom of a parton and the Sudakov resummation of the corresponding large logarithms. We concentrate on the pion and proton electromagnetic form factors and on pion Compton scattering. New ingredients, such as the evolution of the pion wave function and the complete two-loop expression of the Sudakov factor, are included. The sensitivity of our predictions to the infrared cutoff for the Sudakov evolution is discussed. We also elaborate on QCD sum rule methods for Compton Scattering, which provide an alternative description of this process. We show that...
Uncovering the scaling laws of hard exclusive hadronic processes in a comprehensive endpoint model
We show that an endpoint-overlap model can explain the scaling laws observed in exclusive hadronic reactions at large momentum transfer. The model assumes one of the valence quarks carries most of the hadron momentum. Hadron form factors and fixed-angle scattering are related directly to the quark wave function, which can be directly extracted from experimental data. A universal linear endpoint behavior explains the proton electromagnetic form factor, proton-proton fixed-angle scattering, and the t-dependence of proton-proton scattering at large s >> t. Endpoint constituent counting rules relate the number of quarks in a hadron to the power-law behavior. All proton reactions surveyed are consistent with three quarks participating. The model is applicable at laboratory energies and does not need assumptions of asymptotically high energy regime. A rich phenomenology of lepton-hadron scattering and hadron-hadron scattering processes is found in remarkably simple relationships between diverse processes. (orig.)
Joanna Rajchert
2015-11-01
Full Text Available The relationship between exclusion or rejection and aggression is already well documented, but there is still a debate about the mechanisms that underlie this effect. In two studies we focused on the propensity to react aggressively (readiness for aggression on the bases of emotional, cognitive or self-enhancement (personality-immanent processes. In both studies we first measured readiness for aggression and then ego-depleted participants. Next, in Study 1 we excluded participants (n = 96 using an online ball throwing game and measured displaced aggressive behavior - intensity and duration of an unpleasant noise administrated to a stranger. In Study 2 participants (n = 140 were rejected by a peer on the basis of an interview that they gave and then could retaliate by reducing peer's chance for getting a job. The results show that exclusion effect on displaced aggression was moderated by cognitive readiness for aggression, while rejection effect on retaliatory aggression was shaped by emotional and personality-immanent readiness for aggression as well as ego-depletion. The results were discussed in light of the strength model of self-control by Baumeister, Vohs, and Tice (2007.
Hydroclimatological Processes in the Central American Dry Corridor
Hidalgo, H. G.; Duran-Quesada, A. M.; Amador, J. A.; Alfaro, E. J.; Mora, G.
2015-12-01
This work studies the hydroclimatological variability and the climatic precursors of drought in the Central American Dry Corridor (CADC), a subregion located in the Pacific coast of Southern Mexico and Central America. Droughts are frequent in the CADC, which is featured by a higher climatological aridity compared to the highlands and Caribbean coast of Central America. The CADC region presents large social vulnerability to hydroclimatological impacts originated from dry conditions, as there is a large part of population that depends on subsistance agriculture. The influence of large-scale climatic precursors such as ENSO, the Caribbean Low-Level Jet (CLLJ), low frequency signals from the Pacific and Caribbean and some intra-seasonal signals such as the MJO are evaluated. Previous work by the authors identified a connection between the CLLJ and CADC precipitation. This connection is more complex than a simple rain-shadow effect, and instead it was suggested that convection at the exit of the jet in the Costa-Rica and Nicaragua Caribbean coasts and consequent subsidence in the Pacific could be playing a role in this connection. During summer, when the CLLJ is stronger than normal, the Inter-Tropical Convergence Zone (located mainly in the Pacific) displaces to a more southern position, and vice-versa, suggesting a connection between these two processes that has not been fully explained yet. The role of the Western Hemisphere Warm Pool also needs more research. All this is important, as it suggest a working hypothesis that during summer, the effect of the Caribbean wind strength may be responsible for the dry climate of the CADC. Another previous analysis by the authors was based on downscaled precipitation and temperature from GCMs and the NCEP/NCAR reanalysis. The data was later used in a hydrological model. Results showed a negative trend in reanalysis' runoff for 1980-2012 in San José (Costa Rica) and Tegucigalpa (Honduras). This highly significant drying trend
Operating The Central Process Systems At Glenn Research Center
Weiler, Carly P.
2004-01-01
As a research facility, the Glenn Research Center (GRC) trusts and expects all the systems, controlling their facilities to run properly and efficiently in order for their research and operations to occur proficiently and on time. While there are many systems necessary for the operations at GRC, one of those most vital systems is the Central Process Systems (CPS). The CPS controls operations used by GRC's wind tunnels, propulsion systems lab, engine components research lab, and compressor, turbine and combustor test cells. Used widely throughout the lab, it operates equipment such as exhausters, chillers, cooling towers, compressors, dehydrators, and other such equipment. Through parameters such as pressure, temperature, speed, flow, etc., it performs its primary operations on the major systems of Electrical Dispatch (ED), Central Air Dispatch (CAD), Central Air Equipment Building (CAEB), and Engine Research Building (ERB). In order for the CPS to continue its operations at Glenn, a new contract must be awarded. Consequently, one of my primary responsibilities was assisting the Source Evaluation Board (SEB) with the process of awarding the recertification contract of the CPS. The job of the SEB was to evaluate the proposals of the contract bidders and then to present their findings to the Source Selecting Official (SSO). Before the evaluations began, the Center Director established the level of the competition. For this contract, the competition was limited to those companies classified as a small, disadvantaged business. After an industry briefing that explained to qualified companies the CPS and type of work required, each of the interested companies then submitted proposals addressing three components: Mission Suitability, Cost, and Past Performance. These proposals were based off the Statement of Work (SOW) written by the SEB. After companies submitted their proposals, the SEB reviewed all three components and then presented their results to the SSO. While the
Zhu, Chen-Ping; Yang, Hui-Jie; Xiong, Shi-Jie; Gu, Zhi-Ming; Shi, Da-Ning; He, Da-Ren; Wang, Bing-Hong
2007-01-01
Competitive exclusion, a key principle of ecology, can be generalized to understand many other complex systems. Individuals under surviving pressure tend to be different from others, and correlations among them change correspondingly to the updating of their states. We show with numerical simulation that these aptitudes can contribute to group formation or speciation in social fields. Moreover, they can lead to power-law topological correlations of complex networks. By coupling updating states of nodes with variation of connections in a network, structural properties with power-laws and functions like multifractality, spontaneous ranking and evolutionary branching of node states can emerge out simultaneously from the present self-organized model of coevolutionary process.
Time-headway distribution for periodic totally asymmetric exclusion process with various updates
Hrabák, P.; Krbálek, M.
2016-03-01
The totally asymmetric exclusion process (TASEP) with periodic boundaries is considered as traffic flow model. The large-L approximation of the stationary state is used for the derivation of the time-headway distribution (an important microscopic characteristic of traffic flow) for the model with generalized update (genTASEP) in both, forward- and backward-sequential representations. The usually used updates, fully-parallel and regular forward- and backward-sequential, are analyzed as special cases of the genTASEP. It is shown that only for those cases, the time-headway distribution is determined by the flow regardless to the density. The qualitative comparison of the results with traffic data demonstrates that the genTASEP with backward order and attractive interaction evinces similar properties of time-headway distribution as the real traffic sample.
Zone inhomogeneity with the random asymmetric simple exclusion process in a one-lane system
Xiao Song; Cai Jiu-Ju; Liu Fei
2009-01-01
In this paper we use theoretical analysis and extensive simulations to study zone inhomogeneity with the random asymmetric simple exclusion process (ASEP). In the inhomogeneous zone, the hopping probability is less than 1. Two typical lattice geometries axe investigated here. In case A, the lattice includes two equal segments. The hopping probability in the left segment is equal to 1, and in the right segment it is equal to p, which is less than 1. In case B, there are three equal segments in the system; the hopping probabilities in the left and right segments are equal to 1, and in the middle segment it is equal to p, which is leas than 1. Through theoretical analysis, we can discover the effect on these systems when p is changed.
Ferrari, Patrik L.; Spohn, Herbert
2006-07-01
The totally asymmetric simple exclusion process (TASEP) on the one-dimensional lattice with the Bernoulli ρ measure as initial conditions, 0GUE Tracy-Widom distribution. The family [InlineMediaObject not available: see fulltext.] of distribution functions have been obtained before by Baik and Rains in the context of the PNG model with boundary sources, which requires the asymptotics of a Riemann-Hilbert problem. In our work we arrive at [InlineMediaObject not available: see fulltext.] through the asymptotics of a Fredholm determinant. [InlineMediaObject not available: see fulltext.] is simply related to the scaling function for the space-time covariance of the stationary TASEP, equivalently to the asymptotic transition probability of a single second class particle.
R Septiana
2014-06-01
Full Text Available Abstrak __________________________________________________________________________________________ Penelitian ini mengkaji model dinamik yaitu Totally Asymmetric Exclusion Process (TASEP khususnya dalam dua dimensi (2D. Selain itu akan dibahas pula mengenai syarat batas dan aturan dinamika yang digunakan dalam pemodelan ini. TASEP telah diaplikasikan dalam berbagai bidang, salah satunya ialah pemodelan lalu lintas kendaraan (traffic flow. Sistem dua dimensi yang akan dikaji adalah sistem yang diskrit, yakni sistem ke kisi dua dimensi. Sistem ini dimodifikasi menjadi bentuk pertigaan (junction yang searah. Lebih jauh lagi, kendaraan yang melalui pertigaan dimodelkan sebagai partikel yang melompat dari satu kisi ke ke kisi yang lain. Nilai kepadatan dan rapat arus partikel dalam sistem tersebut ditentukan secara numerik. Persamaan kontinuitas untuk menggambarkan dinamika partikel dalam TASEP diselesaikan menggunakan metode Euler. Profil kepadatan dan rapat arus partikel dipengaruhi oleh laju masukan (input rate dan laju keluaran (output rate lompatan partikel. Abstract __________________________________________________________________________________________ The research analyzed a dynamic model of Totally Asymmetric Exclusion Process (TASEP, especially in two dimensions (2D and also the boundary and rules dynamic conditions used in this modeling. TASEP has been applied in various fields, one of them is the modeling of vehicle traffic. Two-dimensional system that will be studied is the discrete system of two-dimensional lattice system. The system is modified into the form of unidirectional T-junction . Furthermore, the vehicles that pass the junction are modeled as particles that jump from one lattice to another lattice. The value of the density and current density of particles in the system is determined numerically. The continuity equation to describe the dynamics of particles in TASEP is solved by using Euler's method. The profiles of
2010-01-01
Graphics Processing Units are immensely powerful processors and for variety applications they outperform the Central Processing Unit, CPU. The recent generations of GPU’s have a flexible architecture than older generations and programming interface more user friendly, which makes them better suited for general purpose programming. A high end GPU can give a desktop computer the same computational power as a small cluster of CPU’s. Speedup of applications by using the GPU has been shown in...
Effects of sleep deprivation on central auditory processing
Liberalesso Paulo Breno
2012-07-01
Full Text Available Abstract Background Sleep deprivation is extremely common in contemporary society, and is considered to be a frequent cause of behavioral disorders, mood, alertness, and cognitive performance. Although the impacts of sleep deprivation have been studied extensively in various experimental paradigms, very few studies have addressed the impact of sleep deprivation on central auditory processing (CAP. Therefore, we examined the impact of sleep deprivation on CAP, for which there is sparse information. In the present study, thirty healthy adult volunteers (17 females and 13 males, aged 30.75 ± 7.14 years were subjected to a pure tone audiometry test, a speech recognition threshold test, a speech recognition task, the Staggered Spondaic Word Test (SSWT, and the Random Gap Detection Test (RGDT. Baseline (BSL performance was compared to performance after 24 hours of being sleep deprived (24hSD using the Student’s t test. Results Mean RGDT score was elevated in the 24hSD condition (8.0 ± 2.9 ms relative to the BSL condition for the whole cohort (6.4 ± 2.8 ms; p = 0.0005, for males (p = 0.0066, and for females (p = 0.0208. Sleep deprivation reduced SSWT scores for the whole cohort in both ears [(right: BSL, 98.4 % ± 1.8 % vs. SD, 94.2 % ± 6.3 %. p = 0.0005(left: BSL, 96.7 % ± 3.1 % vs. SD, 92.1 % ± 6.1 %, p Conclusion Sleep deprivation impairs RGDT and SSWT performance. These findings confirm that sleep deprivation has central effects that may impair performance in other areas of life.
Lebiedowicz, Piotr; Nachtmann, Otto; Szczurek, Antoni
2016-03-01
We consider central exclusive diffractive dipion production in the reactions p p →p p π+π- and p p ¯ →p p ¯ π+π- at high energies. We include the dipion continuum, the dominant scalar f0(500 ), f0(980 ) , and tensor f2(1270 ) resonances decaying into the π+π- pairs. The calculation is based on a tensor Pomeron model and the amplitudes for the processes are formulated in terms of vertices respecting the standard crossing and charge-conjugation relations of quantum field theory. The formulas for the dipion continuum and tensor meson production are given here for the first time. The theoretical results are compared with existing STAR, CDF, CMS experimental data and predictions for planned or current experiments (ALICE, ATLAS) are presented. We show the influence of the experimental cuts on the integrated cross section and on various differential distributions for outgoing particles. Distributions in rapidities and transverse momenta of outgoing protons and pions as well as correlations in azimuthal angle between them are presented. We find that the relative contribution of the resonant f2(1270 ) and dipion continuum strongly depends on the cut on proton transverse momenta or four-momentum transfer squared t1 ,2 which may explain some controversial observations made by different ISR experiments in the past. The cuts may play then the role of a π π resonance filter. We suggest some experimental analyses to fix model parameters related to the Pomeron-Pomeron-f2 coupling.
Farm Process (FMP) Parameters used in the Central Valley Hydrologic Model (CVHM)
U.S. Geological Survey, Department of the Interior — This digital dataset defines the farm-process parameters used in the transient hydrologic model of the Central Valley flow system. The Central Valley encompasses an...
Kazuaki ITO; Kazuhiko TANAKA; Jun SAKAMOTO; Kazuya NAGAOKA; Yohichi TAKAYAMA; Takashi KANAHORI; Hiroshi SUNAHARA; Tsuneo HAYASHI; Shinji SATO; Takeshi HIROKAWA
2012-01-01
The analysis of seven aliphatic carboxylic acids ( formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents (benzoic acid,perfluorobutyric acid (PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet (UV) detection.The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column ( TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column ( TSKgel Super IC-A/C ).Good separation was performed on the TSKgel SCX in shorter retention times.For the TSKgel Super IC-A/C,peak shape of the acids was sharp and symmetrical in spite of longer retention times.In addition,the mutual separation of the acids was good except for iso- and n-butyric acids.The better separation and good detection was achieved by using the two columns (TSKgel SCX and TSKgel Super IC-A/C connected in series),lower concentrations of PFBA and sulfuric acid as eluents,non-suppressed conductivity detection and UV detection at 210 nm.This analysis was applied to anaerobic digestion process waters.The chromatograms with conductivity detection were relatively simpler compared with those of UV detection.The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.
Evaluation of the Central Hearing Process in Parkinson Patients
Santos, Rosane Sampaio; Teive, Hélio A. Ghizoni; Gorski, Leslie Palma; Klagenberg, Karlin Fabianne; Muñoz, Monica Barby; Zeigelboim, Bianca Simone
2011-01-01
Introduction: Parkinson disease (PD) is a degenerating disease with a deceitful character, impairing the central nervous system and causing biological, psychological and social changes. It shows motor signs and symptoms characterized by trembling, postural instability, rigidity and bradykinesia. Objective: To evaluate the central hearing function in PD patients. Method: A descriptive, prospect and transversal study, in which 10 individuals diagnosed of PD named study group (SG) and 10 normall...
Extreme fluctuations of current in the symmetric simple exclusion process: a non-stationary setting
We use the macroscopic fluctuation theory (MFT) to evaluate the probability distribution P of extreme values of integrated current J at a specified time t = T in the symmetric simple exclusion process (SSEP) on an infinite line. As shown recently (Meerson and Sasorov 2014 Phys. Rev. E 89 010101), the SSEP belongs to the elliptic universality class. Here, for very large currents, the diffusion terms of the MFT equations can be neglected compared with the terms coming from the shot noise. Using the hodograph transformation and an additional change of variables, we reduce the ‘inviscid’ MFT equations to Laplace’s equation in an extended space. This opens the way to an exact solution. Here we solve the extreme-current problem for a flat deterministic initial density profile with an arbitrary density 0 0 0)J3/T, in agreement with Derrida and Gerschenfeld (2009 J. Stat. Phys. 137 978). We calculate the function Φ(n0) analytically. It is symmetric with respect to the half-filling density n0 = 1/2, diverges at n0 → 0 and n0 → 1 and exhibits a singularity Φ(n0) ∼ |n0−1/2| at the half-filling density n0 = 1/2. (paper)
Phase transition in 2D partially asymmetric simple exclusion process with two species
The dynamics of two species of particles undergoing asymmetric simple exclusion process (ASEP) on the 2D lattice are investigated in this paper. A sharp transition from moving phase to jamming phase was shown under periodic boundary conditions. We have developed a mean field analysis for the moving phase by extending the method of [33] and this produces good agreement with simulation results. Two types of jamming phase were observed. In the first type of jamming phase, some particles at the border of the jamming cluster could move back and forth due to the ASEP rule. The first type of jamming phase reduces to the 1D ASEP with a barrier at the boundary of the lattice. We also have analyzed the average hops for the first type of jamming phase by analyzing the 1D ASEP model. The analytical results agree with the simulation results well. Under open boundary conditions, the system exhibits two phases when forward hopping probability q is larger than 0.5. The particles form a wall at the entrance when q is smaller than 0.5. The dependence of the average velocity, the density and the flow rate on the injection probability in the moving phase have also been obtained through mean field analysis. (paper)
Bi-orthogonal polynomial sequences and the asymmetric simple exclusion process
Brak, R.; Moore, W.
2015-08-01
We state the diffusion algebra equations of the stationary state of the three parameter (α, β and q) asymmetric simple exclusion Process as a linear functional {L}, acting on a tensor algebra. From {L} we construct a pair of sequences, \\{{P}n\\} and \\{{Q}m\\}, of monic polynomials which are bi-orthogonal, that is, they satisfy {L}({P}n{Q}m)={Λ }n{δ }n,m(where {Λ }n is a scalar). The uniqueness and existence of the pair of sequences arises from the determinant of the bi-moment matrix whose elements satisfy a pair of q-recurrence relations. The determinant is evaluated using an LDU-decomposition. If the linear functional is represented as an inner product, {L}(\\cdot )= then the action of the polynomials Qn on the boundary vector | V> generate a basis | {V}n> ={Q}n| V> whose orthogonal dual vectors are given by the action of Pn on the dual boundary vector Salam-Chihara polynomials obtained by Sasamoto.
Hydrodynamic mean-field solutions of 1D exclusion processes with spatially varying hopping rates
Lakatos, Greg; O' Brien, John; Chou, Tom [Department of Biomathematics and Institute for Pure and Applied Mathematics, UCLA, Los Angeles, CA 90095 (United States)
2006-03-10
We analyse the open boundary partially asymmetric exclusion process with smoothly varying internal hopping rates in the infinite-size, mean-field limit. The mean-field equations for particle densities are written in terms of Ricatti equations with the steady-state current J as a parameter. These equations are solved both analytically and numerically. Upon imposing the boundary conditions set by the injection and extraction rates, the currents J are found self-consistently. We find a number of cases where analytic solutions can be found exactly or approximated. Results for J from asymptotic analyses for slowly varying hopping rates agree extremely well with those from extensive Monte Carlo simulations, suggesting that mean-field currents asymptotically approach the exact currents in the hydrodynamic limit, as the hopping rates vary slowly over the lattice. If the forward hopping rate is greater than or less than the backward hopping rate throughout the entire chain, the three standard steady-state phases are preserved. Our analysis reveals the sensitivity of the current to the relative phase between the forward and backward hopping rate functions.
An exclusion process on a tree with constant aggregate hopping rate
We introduce a model of a totally asymmetric simple exclusion process (TASEP) on a tree network where the aggregate hopping rate is constant from level to level. With this choice for hopping rates the model shows the same phase diagram as the one-dimensional case. The potential applications of our model are in the area of distribution networks, where a single large source supplies material to a large number of small sinks via a hierarchical network. We show that mean-field theory (MFT) for our model is identical to that of the one-dimensional TASEP and that this MFT is exact for the TASEP on a tree in the limit of large branching ratio, b (or equivalently large coordination number). We then present an exact solution for the two level tree (or star network) that allows the computation of any correlation function and confirm how mean-field results are recovered as b → ∞. As an example we compute the steady-state current as a function of branching ratio. We present simulation results that confirm these results and indicate that the convergence to MFT with large branching ratio is quite rapid. (paper)
Ciandrini, L.; Stansfield, I; Romano, M. C.
2009-01-01
Messenger RNA translation is often studied by means of statistical-mechanical models based on the Asymmetric Simple Exclusion Process (ASEP), which considers hopping particles (the ribosomes) on a lattice (the polynucleotide chain). In this work we extend this class of models and consider the two fundamental steps of the ribosome’s biochemical cycle following a coarse-grained perspective. In order to achieve a better understanding of the underlying biological processes and compare the theoret...
Jaime A Usma Wilches
2009-01-01
This paper examines the National Bilingual Program in connection with other education and language reforms in Colombia and some of the processes of inclusion, exclusion, and stratification that accompany current school reforms. The author outlines some patterns that have accompanied language innovations in the country and highlights some interconnected processes that seem to be favored in international reform and are reflected in current national policy agendas; namely, the externalization...
2012-08-21
... groundfish of the GOA (77 FR 15194, March 14, 2012). In accordance with Sec. 679.20(d)(2), the Administrator... Central Regulatory Area of the Gulf of Alaska (GOA). This action is necessary because the 2012 total allowable catch of ``other rockfish'' in the Central Regulatory Area of the GOA has been reached....
Nepstad, D. C.; Moutinho, P.; Dias-Filho, M. B.; Davidson, E.; Cardinot, G.; Markewitz, D.; Figueiredo, R.; Vianna, N.; Chambers, J.; Ray, D.; Guerreiros, J. B.; Lefebvre, P.; Sternberg, L.; Moreira, M.; Barros, L.; Ishida, F. Y.; Tohlver, I.; Belk, E.; Kalif, K.; Schwalbe, K.
2002-10-01
Moist tropical forests in Amazonia and elsewhere are subjected to increasingly severe drought episodes through the El Niño-Southern Oscillation (ENSO) and possibly through deforestation-driven reductions in rainfall. The effects of this trend on tropical forest canopy dynamics, emissions of greenhouse gases, and other ecological functions are potentially large but poorly understood. We established a throughfall exclusion experiment in an east-central Amazon forest (Tapajós National Forest, Brazil) to help understand these effects. After 1-year intercalibration period of two 1-ha forest plots, we installed plastic panels and wooden gutters in the understory of one of the plots, thereby excluding ˜890 mm of throughfall during the exclusion period of 2000 (late January to early August) and ˜680 mm thus far in the exclusion period of 2001 (early January to late May). Average daily throughfall reaching the soil during the exclusion period in 2000 was 4.9 and 8.3 mm in the treatment and control plots and was 4.8 and 8.1 mm in 2001, respectively. During the first exclusion period, surface soil water content (0-2 m) declined by ˜100 mm, while deep soil water (2-11 m) was unaffected. During the second exclusion period, which began shortly after the dry season when soil water content was low, surface and deep soil water content declined by ˜140 and 160 mm, respectively. Although this depletion of soil water provoked no detectable increase in leaf drought stress (i.e., no reduction in predawn leaf water potential), photosynthetic capacity declined for some species, the canopy thinned (greater canopy openness and lower leaf area index) during the second exclusion period, stem radial growth of trees litter production) declined by one fourth, from 15.1 to 11.4 Mg ha-1 yr-1, in the treatment plot and decreased slightly, from 11.9 to 11.5 Mg ha-1 yr-1, in the control plot. Stem respiration varied seasonally and was correlated with stem radial growth but showed no treatment
Brando, Paulo; Ray, David; Nepstad, Daniel; Cardinot, Gina; Curran, Lisa M; Oliveira, Rafael
2006-11-01
Severe droughts may alter the reproductive phenology of tropical tree species, but our understanding of these effects has been hampered by confounded variation in drought, light and other factors during natural drought events. We used a large-scale experimental reduction of throughfall in an eastern-central Amazon forest to study the phenological response to drought of an abundant subcanopy tree, Coussarea racemosa. We hypothesized that drought would alter the production and the timing of reproduction, as well as the number of viable fruits. The study system comprised two 1-ha plots in the Tapajos National Forest, Para, Brazil: a dry plot where 50% of incoming precipitation (80% throughfall) was diverted from the soil during the six-month wet season beginning in January 2000, and a wet plot that received natural rainfall inputs. Fruit production of C. racemosa was quantified every 15 days using 100 litter traps (0.5 m(2)) in each plot. The production of new leaves and flowers was recorded monthly for C. racemosa individuals. Soil water, pre-dawn leaf water potential and solar radiation were measured to help interpret phenological patterns. Over the approximately 3.5-year period (April 2000 through December 2003), total fruit production remained similar between plots, declining by 12%. In 2003, production was four times higher in both plots than in previous years. In the dry plot, fruit fall shifted 40 and 60 days later into the dry season in 2002 and 2003, respectively. Total fruit fall dry mass production was variable across the study period. Foliage and flower production coincided with peak irradiance early in the dry season until delays in flowering appeared in the dry plot in 2002 and 2003. Plant water stress, through its influence on leaf developmental processes and, perhaps, inhibition of photosynthesis, appears to have altered both the timing of fruit fall and the quality and number of seeds produced. PMID:16955290
Establishing a central waste processing and storage facility in Ghana
regulations. About 50 delegates from various ministries and establishment participated in the seminar. The final outcome of the draft regulation was sent to the Attorney General's office for the necessary legal review before been presented to Parliament through the Ministry of Environment, Science and Technology. A radiation sources and radioactive waste inventory have been established using the Regulatory Authority Information System (RAIS) and the Sealed Radiation Sources Registry System (SRS). A central waste processing and storage facility was constructed in the mid sixties to handle waste from a 2MW reactor that was never installed. The facility consists of a decontamination unit, two concrete vaults (about 5x15 m and 4m deep) intended for low and intermediate level waste storage and 60 wells (about 0.5m diameter x 4.6m) for storage of spent fuel. This Facility will require significant rehabilitation. Safety and performance assessment studies have been carried out with the help of three IAEA experts. The recommendations from the assessment indicate that the vaults are very old and deteriorated to be considered for any future waste storage. However the decontamination unit and the wells are still in good condition and were earmarked for refurbishment and use as waste processing and storage facilities respectively. The decontamination unit has a surface area of 60m2 and a laboratory of surface area 10m2. The decontamination unit will have four technological areas. An area for cementation of non-compactible solid waste and spent sealed sources. An area for compaction of compactable solid waste and a controlled area for conditioned wastes in 200L drums. Provision has been made to condition liquid waste. There will be a section for receipt and segregation of the waste. The laboratory will be provided with the necessary equipment for quality control. Research to support technological processes will be carried out in the laboratory. A quality assurance and control systems shall
Flores, J C
2016-03-01
This work applies the competitive exclusion principle and the concept of potential competitors as simple axiomatic tools to generalized situations in ecology. These tools enable apparent competition and its dual counterpart to be explicitly evaluated in poorly understood ecological systems. Within this set-theory framework we explore theoretical symmetries and invariances, De Morgan's laws, frozen evolutionary diversity and virtual processes. In particular, we find that the exclusion principle compromises the geometrical growth of the number of species. By theoretical extending this principle, we can describe interspecific depredation in the dual case. This study also briefly considers the debated situation of intraspecific competition. The ecological consequences of our findings are discussed; particularly, the use of our framework to reinterpret coupled mathematical differential equations describing certain ecological processes. PMID:26801920
COST OF PROCESSING CARROT PRODUCTION IN WEST CENTRAL MICHIGAN
Dartt, Barbara; Black, J. Roy; Breinling, Jim; Morrone, Vicki
2002-01-01
This bulletin represents a tool that can help producers, consultants, educators, and agribusinesses working with producers estimate costs of production and expected profit based on "typical" carrot management strategies found in west central Michigan. The budget included in this bulletin will allow users to revise inputs based on their management strategies and calculate their expected cost and profit. This flexibility provides a decision aid to search for systems that generate higher net ret...
Searching saturation effects in inclusive and exclusive eA processes
Goncalves V. P.
2016-01-01
Full Text Available The searching of saturation effects in inclusive and exclusive eA collisions is reviewed. In particular, we present a comparison between the linear and non-linear predictions for the nuclear structure functions as well as for the Deep Virtual Compton Scattering and vector meson production in future eA colliders.
Improving management decision processes through centralized communication linkages
Simanton, D. F.; Garman, J. R.
1985-01-01
Information flow is a critical element to intelligent and timely decision-making. At NASA's Johnson Space Center the flow of information is being automated through the use of a centralized backbone network. The theoretical basis of this network, its implications to the horizontal and vertical flow of information, and the technical challenges involved in its implementation are the focus of this paper. The importance of the use of common tools among programs and some future concerns related to file transfer, graphics transfer, and merging of voice and data are also discussed.
2013-05-13
... established by the final 2013 and 2014 harvest specifications for groundfish of the GOA (78 FR 13162, February... of the Gulf of Alaska (GOA). This action is necessary because the 2013 total allowable catch of big skate in the Central Regulatory Area of the GOA has been reached. DATES: Effective 1200 hrs,...
2010-11-30
... and 2011 harvest specifications for groundfish of the GOA (75 FR 11749, March 12, 2010). In accordance... of the Gulf of Alaska (GOA). This action is necessary because the 2010 total allowable catch (TAC) of big skate in the Central Regulatory Area of the GOA has been reached. DATES: Effective 1200...
2012-12-20
... established by the final 2012 and 2013 harvest specifications for groundfish of the GOA (77 FR 15194, March 14... of the Gulf of Alaska (GOA). This action is necessary because the 2012 total allowable catch of big skate in the Central Regulatory Area of the GOA has been reached. DATES: Effective 1200 hrs,...
2010-07-02
... Economic Zone Off Alaska; Central Gulf of Alaska License Limitation Program; Amendment 86 AGENCY: National... the Gulf of Alaska (FMP) to NMFS for review. If approved, Amendment 86 would add a Pacific cod... of Amendment 86 to the Fishery Management Plan for Groundfish of the Gulf of Alaska, and...
2011-07-28
... Economic Zone Off Alaska; Central Gulf of Alaska Rockfish Program; Amendment 88 AGENCY: National Marine... submitted Amendment 88 to the Fishery Management Plan for Groundfish of the Gulf of Alaska (FMP) for review... gains realized under the Rockfish Pilot Program and viability of the Gulf of Alaska fisheries....
2013-03-04
...NMFS publishes the standard ex-vessel prices and fee percentage for cost recovery under the Central Gulf of Alaska Rockfish Program. This action is intended to provide participants in a rockfish cooperative with the standard prices and fee percentage for the 2012 fishing year, which was authorized from May 1 through November 15. The fee percentage is 1.4 percent. The fee liability payments......
An anti-symmetric exclusion process for two particles on an infinite 1D lattice
A system of two biased, mutually exclusive random walkers on an infinite 1D lattice is studied whereby the intrinsic bias of one particle is equal and opposite to that of the other. The propagator for this system is solved exactly and expressions for the mean displacement and mean square displacement (MSD) are found. Depending on the nature of the intrinsic bias, the system’s behaviour displays two regimes, characterised by (i) the particles moving towards each other and (ii) away from each other, both qualitatively different from the case of no bias. The continuous-space limit of the propagator is found and is shown to solve a Fokker–Planck equation for two biased, mutually exclusive Brownian particles with equal and opposite drift velocity. Connections to territorial dynamics in animal populations are discussed. (paper)
An anti-symmetric exclusion process for two particles on an infinite 1D lattice
Potts, J R; Giuggioli, L [Bristol Centre for Complexity Sciences, University of Bristol, Bristol (United Kingdom); Harris, S, E-mail: jonathan.potts.08@bris.ac.uk [School of Biological Sciences, University of Bristol, Bristol (United Kingdom)
2011-12-02
A system of two biased, mutually exclusive random walkers on an infinite 1D lattice is studied whereby the intrinsic bias of one particle is equal and opposite to that of the other. The propagator for this system is solved exactly and expressions for the mean displacement and mean square displacement (MSD) are found. Depending on the nature of the intrinsic bias, the system's behaviour displays two regimes, characterised by (i) the particles moving towards each other and (ii) away from each other, both qualitatively different from the case of no bias. The continuous-space limit of the propagator is found and is shown to solve a Fokker-Planck equation for two biased, mutually exclusive Brownian particles with equal and opposite drift velocity. Connections to territorial dynamics in animal populations are discussed. (paper)
An anti-symmetric exclusion process for two particles on an infinite 1D lattice
Potts, J. R.; Harris, S.; Giuggioli, L.
2011-12-01
A system of two biased, mutually exclusive random walkers on an infinite 1D lattice is studied whereby the intrinsic bias of one particle is equal and opposite to that of the other. The propagator for this system is solved exactly and expressions for the mean displacement and mean square displacement (MSD) are found. Depending on the nature of the intrinsic bias, the system’s behaviour displays two regimes, characterised by (i) the particles moving towards each other and (ii) away from each other, both qualitatively different from the case of no bias. The continuous-space limit of the propagator is found and is shown to solve a Fokker-Planck equation for two biased, mutually exclusive Brownian particles with equal and opposite drift velocity. Connections to territorial dynamics in animal populations are discussed.
Hoang, Huong
2016-01-01
This thesis documents the process of a centralization project for Maintenance, Repair and Operations (MRO) procurement and the incentives behind the project, as well as discusses the problem attributes, and recommends solutions on how to improve the operational sides of the project in company X. The research questions seek answers for a particular and standardized process to implement the centralization procurement process for MRO items, the reason why MRO items, especially the packaging ...
WANG YUEBAO; YANG YANG; ZHOU HAIYANG
2003-01-01
A random functional central limit theorem is obtained for processes of partial sums andproduct sums of linear processes generated by non-stationary martingale differences. It devel-ops and improves some corresponding results on processes of partial sums of linear processesgenerated by strictly stationary martingale differences, which can be found in [5].
Sawada, Takahiro; Kumano, Shunzo; Peng, Jen-Chieh; Sawada, Shinya; Tanaka, Kazuhiro
2016-01-01
Generalized parton distributions (GPDs) encoding multi-dimensional information of hadron partonic structure appear as the building blocks in a factorized description of hard exclusive reactions. The nucleon GPDs have been accessed by deeply virtual Compton scattering and deeply virtual meson production with lepton beam. A complementary probe with hadron beam is the exclusive pion-induced Drell-Yan process. In this paper, we discuss recent theoretical advances on describing this process in terms of nucleon GPDs and pion distribution amplitudes. Furthermore, we address the feasibility of measuring the exclusive pion-induced Drell-Yan process $\\pi^- p \\to \\mu^+\\mu^- n$ via a spectrometer at the High Momentum Beamline being constructed at J-PARC in Japan. Realization of such measurement at J-PARC will provide a new test of perturbative QCD descriptions of a novel class of hard exclusive reactions. It will also offer the possibility of experimentally accessing nucleon GPDs at large timelike virtuality.
Guiot, B
2002-12-01
The INDRA multidetector allowed us to study the Ni+Ni collisions at 32A MeV and the Ni+Au collisions at 52,4 MeV. Central collisions leading to 'quasi-fused' systems were isolated using multidimensional analysis techniques: the Discriminant Analysis and the Principal Component Analysis. Comparison with a statistical model shows that the selected events are compatible with thermodynamical equilibrium. The average thermal excitation energy is 5A MeV for both systems. Calculations of heat capacities show that the deexcitation of the hot sources are akin to a liquid-gas phase transition of nuclear matter. Indeed heat capacities exhibit a negative branch as expected for a phase transition of a finite system. The dynamics of this phase transition has been investigated by applying the charge correlation method. An enhanced production of events with equal-sized fragments has been evidenced for Ni+Au at 52A MeV. No signal was found for Ni+Ni at 32A MeV. Finally this method was improved by taking into account the total charge conservation. The signal is seen more clearly for Ni+Au at 52A MeV, but is ambiguous for Ni+Ni at 32A MeV. The path followed in the state diagram, or the involved time scales, seem to be different for these systems. (authors)
Perceptual weights for loudness reflect central spectral processing.
Joshi, Suyash Narendra; Jesteadt, Walt
2011-01-01
Weighting patterns for loudness obtained using the reverse correlation method are thought to reveal the relative contributions of different frequency regions to total loudness, the equivalent of specific loudness. Current models of loudness assume that specific loudness is determined by peripheral processes such as compression and masking. Here we test this hypothesisusing 20-tone harmonic complexes (200Hz f0, 200 to 4000Hz, 250 ms, 65 dB/Component) added in opposite phase relationships (Schr...
A Comprehensive Review for Central Processing Unit Scheduling Algorithm
Ryan Richard H. Guadaandntilde;a; Maria Rona Perez; Larry T. Rutaquio Jr.
2013-01-01
This paper describe how does CPU facilitates tasks given by a user through a Scheduling Algorithm. CPU carries out each instruction of the program in sequence then performs the basic arithmetical, logical, and input/output operations of the system while a scheduling algorithm is used by the CPU to handle every process. The authors also tackled different scheduling disciplines and examples were provided in each algorithm in order to know which algorithm is appropriate for various CPU goals.
Connections between exclusive and inclusive electron scattering are explored within the framework of the relativistic plane-wave impulse approximation, beginning with an analysis of the model-independent kinematical constraints to be found in the missing-energy - missing-momentum plane. From the interplay between these constraints and the spectral function basic features of the exclusive and inclusive nuclear responses are seen to arise. In particular, the responses of the relativistic Fermi gas and of a specific hybrid model with bound nucleons in the initial state are compared. The latter facilitates extrapolations from light nuclei to very heavy ones where the former model has some validity. As expected, the exclusive responses are significantly different in the two models, whereas the inclusive ones are rather similar. By extending previous work on the relativistic Fermi gas, a reduced response is introduced for the hybrid model such that it fulfills the Coulomb and the higher-power energy-weighted sum rules. Although incorporating specific classes of off-shellness for the struck nucleons, it is found that the reducing factor required is largely model independent and, as such, yields a reduced response that is useful for studies of scaling and of the Coulomb sum rule. In particular, guided by the difference between the energy-weighted sum rules of the two models a new scaling variable appropriate for heavy nuclei is devised. Finally, a version of the relativistic Fermi gas which has zeroth, first, and second energy-weighted moments of the longitudinal response that agree rather well with those of the hybrid model is constructed: this version thus incorporates a priori the binding effects of the struck nucleons while retaining the simplicity of the original Fermi gas and provides the basis for future extensions of the model. copyright 1997 The American Physical Society
Central Auditory Processing of Temporal and Spectral-Variance Cues in Cochlear Implant Listeners.
Carol Q Pham
Full Text Available Cochlear implant (CI listeners have difficulty understanding speech in complex listening environments. This deficit is thought to be largely due to peripheral encoding problems arising from current spread, which results in wide peripheral filters. In normal hearing (NH listeners, central processing contributes to segregation of speech from competing sounds. We tested the hypothesis that basic central processing abilities are retained in post-lingually deaf CI listeners, but processing is hampered by degraded input from the periphery. In eight CI listeners, we measured auditory nerve compound action potentials to characterize peripheral filters. Then, we measured psychophysical detection thresholds in the presence of multi-electrode maskers placed either inside (peripheral masking or outside (central masking the peripheral filter. This was intended to distinguish peripheral from central contributions to signal detection. Introduction of temporal asynchrony between the signal and masker improved signal detection in both peripheral and central masking conditions for all CI listeners. Randomly varying components of the masker created spectral-variance cues, which seemed to benefit only two out of eight CI listeners. Contrastingly, the spectral-variance cues improved signal detection in all five NH listeners who listened to our CI simulation. Together these results indicate that widened peripheral filters significantly hamper central processing of spectral-variance cues but not of temporal cues in post-lingually deaf CI listeners. As indicated by two CI listeners in our study, however, post-lingually deaf CI listeners may retain some central processing abilities similar to NH listeners.
Exclusive $J/\\psi$ Production in Diffractive Process with AdS/QCD Holographic Wave Function in BLFQ
Xie, Ya-ping; Zhao, Xingbo
2016-01-01
The AdS/QCD holographic wave function of basis light-front quantization (BLFQ) for vector meson $J/\\psi$ is applied in this manuscript. The exclusive production of $J/\\psi$ in diffractive process is computed in dipole model with AdS/QCD holographic wave function. We use IP-Sat and IIM model in the calculation of the differential cross section of the dipole scattering off the proton. The prediction of AdS/QCD holographic wave function in BLFQ gives a good agreement to the experimental data.
Chavez, E.; Landim, C.
2016-06-01
We consider a one-dimensional, weakly asymmetric, boundary driven exclusion process on the interval [0,N]\\cap {Z} in the quasi-static time scale N^2 ɛ ^{-1}_N, where 1≪ ɛ ^{-1}_N ≪ N^{1/4}. We assume that the external field and the chemical potentials, which fix the density at the boundaries, evolve smoothly in the macroscopic time scale. We derive an equation which describes the evolution of the density up to the order ɛ _N.
Stakeholder consultations regarding centralized power procurement processes in Ontario
In 2004, Ontario held 4 Requests for Proposals (RFPs) to encourage the development of new clean renewable combined heat and power generation and the implementation of conservation and demand management programs. Details of a stakeholder consultation related to the RFP process were presented were in this paper. The aim of the consultation was to synthesize stakeholder comments and to provide appropriate recommendations for future RFPs held by the Ontario Power Authority (OPA). The financial burden of bidding was discussed, as well as communications procedures and contract ambiguities. Issues concerning the criteria used for qualifying potential bidders and evaluating project submissions were reviewed. Recommendations for future processes included prequalification, a simplification in collusion requirements, and a fixed time response. It was also recommended that the process should not emphasize financing as lenders do not make firm commitments to bidders prior to a bid being accepted. It was suggested that the amount of bid security should vary with the project size and phase of development, and that the contracts for differences format should be refined to allow participants to propose parameters. Issues concerning audit procedures and performance deviations were reviewed. It was suggested that contract terms should be compatible with gas markets. It was also suggested that the OPA should adopt a more simplified approach to co-generation proposals, where proponents can specify amounts of energy and required prices. The adoption of the Swiss challenge approach of allowing other vendors an opportunity to match or beat terms on an offer was recommended. It was suggested that renewables should be acquired through a targeted and volume limited standard-offer process to be set yearly. Conservation and demand management recommendations were also presented. It was suggested that the OPA should serve as a facilitator of clean development mechanism (CDM) programs. It was
Cassava Processing and Marketing by Rural Women in the Central Region of Cameroon
SHIOYA, Akiyo
2013-01-01
This study examines the development of rural women's commercial activities in Central Cameroon, particularly the Department of Lekié, which is adjacent to Yaoundé, the capital of Cameroon. I focused on cassava processing technologies and the sale of cassavabased processed foods undertaken by women in a suburban farming village. Cassava is one of the main staple foods in central Cameroon, including in urban areas. One of its characteristics is that it keeps for a long period in the ground but ...
Solar augmentation for process heat with central receiver technology
Kotzé, Johannes P.; du Toit, Philip; Bode, Sebastian J.; Larmuth, James N.; Landman, Willem A.; Gauché, Paul
2016-05-01
Coal fired boilers are currently one of the most widespread ways to deliver process heat to industry. John Thompson Boilers (JTB) offer industrial steam supply solutions for industry and utility scale applications in Southern Africa. Transport cost add significant cost to the coal price in locations far from the coal fields in Mpumalanga, Gauteng and Limpopo. The Helio100 project developed a low cost, self-learning, wireless heliostat technology that requires no ground preparation. This is attractive as an augmentation alternative, as it can easily be installed on any open land that a client may have available. This paper explores the techno economic feasibility of solar augmentation for JTB coal fired steam boilers by comparing the fuel savings of a generic 2MW heliostat field at various locations throughout South Africa.
Central pain processing in chronic tension-type headache
Lindelof, Kim; Ellrich, Jens; Jensen, Rigmor;
2009-01-01
OBJECTIVE: Chronic tension-type headache (CTTH) affects 3% of the population. Directly and indirectly it causes high costs and considerable loss of quality of life. The mechanisms of this disorder are poorly understood and the treatment possibilities are therefore limited. The blink reflex (BR) r...... combined homotopic and heterotopic effect of the conditioning pain onto the blink reflex could account for this finding.......) reflects neuronal excitability due to nociceptive input in the brainstem. The aim of this study was to investigate nociceptive processing at the level of the brainstem in an experimental pain model of CTTH symptoms. METHODS: The effect of conditioning pain, 5 min infusion of hypertonic saline into the neck...... muscles, was investigated in 20 patients with CTTH and 20 healthy controls. In addition, a pilot study with isotonic saline was performed with 5 subjects in each group. The BR was elicited by electrical stimuli with an intensity of four times the pain threshold, with a superficial concentric electrode. We...
Exclusive study of Ni+Ni and Ni+Au central collisions: phase coexistence and spinodal decomposition
The INDRA multidetector allowed us to study the Ni+Ni collisions at 32A MeV and the Ni+Au collisions at 52,4 MeV. Central collisions leading to 'quasi-fused' systems were isolated using multidimensional analysis techniques: the Discriminant Analysis and the Principal Component Analysis. Comparison with a statistical model shows that the selected events are compatible with thermodynamical equilibrium. The average thermal excitation energy is 5A MeV for both systems. Calculations of heat capacities show that the deexcitation of the hot sources are akin to a liquid-gas phase transition of nuclear matter. Indeed heat capacities exhibit a negative branch as expected for a phase transition of a finite system. The dynamics of this phase transition has been investigated by applying the charge correlation method. An enhanced production of events with equal-sized fragments has been evidenced for Ni+Au at 52A MeV. No signal was found for Ni+Ni at 32A MeV. Finally this method was improved by taking into account the total charge conservation. The signal is seen more clearly for Ni+Au at 52A MeV, but is ambiguous for Ni+Ni at 32A MeV. The path followed in the state diagram, or the involved time scales, seem to be different for these systems. (authors)
The LHCb Collaboration
2016-01-01
A measurement is made of the central exclusive production of $J/\\psi$ and $\\psi(2S)$ mesons in $pp$ collisions at a centre-of-mass energy of 13 TeV. Backgrounds are significantly reduced compared to previous measurements made at lower energies through the use of new forward shower counters. The cross-section times branching fractions for the decays to dimuons, where both muons are within the pseudorapidity region $2<\\eta<4.5$, are measured to be $$ \\begin{array}{rcl} \\sigma_{J/\\psi\\rightarrow\\mu^+\\mu^-}(2.0<\\eta_{\\mu^+},\\eta{\\mu^-}<4.5)&=&407\\pm 8\\pm 24 \\pm 16 {\\rm \\ pb} \\\\ \\sigma_{\\psi(2S)\\rightarrow\\mu^+\\mu^-}(2.0<\\eta_{\\mu^+},\\eta{\\mu^-}<4.5)&=&9.4\\pm 0.9\\pm 0.6 \\pm 0.4 {\\rm \\ pb.}\\\\ \\end{array} $$ where the first uncertainty is statistical, the second is systematic, and the third is due to the luminosity determination. The cross-sections are also measured differentially in ten bins of pseudorapidity for the $J/\\psi$ meson and in three bins for the $\\psi(2S)$. Good agree...
Exclusive quarkonium production in pp collisions
Central exclusive production (CEP) processes in high-energy proton - (anti)proton collisions offer a very promising framework within which to study both novel aspects of QCD and new physics signals. Among the many interesting processes that can be studied in this way, those involving the production of heavy (c,b) quarkonia states are of particular importance, serving as 'standard candle' processes with which we can benchmark predictions for new physics CEP at the CERN Large Hadron Collider, as well as being of interest in their own right. We report on our recent quantitative studies of exclusive heavy quarkonia (χ and η) production, and make cross section predictions for the LHC, Tevatron and RHIC. We also examine the possibility of observing quarkonium CEP at RHIC with tagged forward protons, for which measurements of the outgoing proton momenta would provide interesting spin-parity information about the centrally produced state.
Central Data Processing System (CDPS) users manual: solar heating and cooling program
1976-09-01
The Central Data Processing System (CDPS) provides the software and data base management system required to assess the performance of solar heating and cooling systems installed at multiple remote sites. The instrumentation data associated with these systems is collected, processed, and presented in a form which supports continuity of performance evaluation across all applications. The CDPS consists of three major elements: communication interface computer, central data processing computer, and performance evaluation data base. The CDPS Users Manual identifies users of the performance data base, procedures for operation, and guidelines for software maintenance. The manual also defines the output capabilities of the CDPS in support of external users of the system.
Central limit theorems for smoothed extreme value estimates of Poisson point processes boundaries
Girard, Stéphane; Menneteau, Ludovic
2011-01-01
In this paper, we give sufficient conditions to establish central limit theorems for boundary estimates of Poisson point processes. The considered estimates are obtained by smoothing some bias corrected extreme values of the point process. We show how the smoothing leads Gaussian asymptotic distributions and therefore pointwise confidence intervals. Some new unidimensional and multidimensional examples are provided.
Central limit theorems for smoothed extreme value estimates of point processes boundaries
Girard, Stéphane; Menneteau, Ludovic
2005-01-01
In this paper, we give sufficient conditions to establish central limit theorems for boundary estimates of Poisson point processes. The considered estimates are obtained by smoothing some bias corrected extreme values of the point process. We show how the smoothing leads Gaussian asymptotic distributions and therefore pointwise confidence intervals. Some new unidimensional and multidimensional examples are provided.
Exclusion, employment and opportunity
Atkinson, Tony; Hills, John
1998-01-01
The relationships between employment, education, opportunity, social exclusion and poverty are central to current policy debates. Atkinson argues that the concepts of poverty, unemployment and social exclusion are closely related, but are not the same. People may be poor without being socially excluded, and vice versa. Unemployment may cause poverty, but this can be prevented. Equally, marginal jobs do not ensure social inclusion. Britton argues that convential economic analysis misses a key ...
Musatov, I V
1997-01-01
We analyze effects due to transverse degrees of freedom in QCD calculations of the fundamental hard exclusive amplitude of $\\gamma^*\\gamma \\to \\pi^0$ transition. A detailed discussion is given of the relation between the modified factorization approach (MFA) of Sterman {\\it et al.} and standard factorization (SFA). Working in Feynman gauge, we construct basic building blocks of MFA from the one-loop coefficient function of the SFA, demonstrating that Sudakov effects are distinctly different from higher-twist corrections. We show also that the handbag-type diagram, contrary to naive expectations, does not contain an infinite chain of $(M^2/Q^2)^n$ corrections: they come only from diagrams with transverse gluons emitted from the hard propagator. A simpler picture emerges within the QCD sum rule approach: the sum over soft $\\bar q G \\ldots G q$ Fock components is dual to $\\bar qq$ states generated by the local axial current. We combine the results based on QCD sum rules with pQCD radiative corrections and observ...
Business process reengineering in the centralization of the industrial enterprises management
N.I. Chukhray
2015-09-01
Full Text Available The aim of the article. One of the important strategic directions of the powerful independent state with a stable economy is the development of the national economy, which requires the use of new upgraded tools that will enable to redesign and improve the production and management activities of the enterprise and make it more productive and competitive, while providing the economy of the financial, labor and other resources. However, this presupposes the use of partial restructuring and in some cases complete restructuring of the business processes. The aim of the article is to study business processes reengineering features at domestic enterprises and the development of business processes centralization algorithm on the example of JSC «Concern-Electron». To achieve this goal, the research identifies the following objectives: to summarize the main approaches to the business processes reengineering on the basis of centralization; to characterize the main stages in the reengineering implementation at industrial enterprise; to propose the selection mechanism of the subsidiary business processes for reengineering; to determine the algorithm of the business processes management centralization. The results of the analysis. The paper summarizes main approaches to business process reengineering based on the centralization; undertakes the characteristic advantages of its use at the industrial enterprises; proposes the stages of reengineering for Ukrainian industrial enterprises. Business process reengineering improves the efficiency of work organization at the JSC «Concern- Electron»: a generalized approach to the centralization of the industrial enterprise management, the algorithm of the business process management centralization that includes identification of the business processes that are duplicated; business process selection for the reengineering using the fuzzy set theory; making managerial decisions on reengineering. Conclusions and
Lämsä, Jerry W
2011-01-01
The ALICE experiment is shown to be well suited for studies of exclusive final states from central diffractive reactions. The gluon-rich environment of the central system allows detailed QCD studies and searches for exotic meson states, such as glueballs, hybrids and new charmonium-like states. It would also provide a good testing ground for detailed studies of heavy quarkonia. Due to its central barrel performance, ALICE can accurately measure the low-mass central systems with good purity. The efficiency of the Forward Multiplicity Detector (FMD) and the Forward Shower Counter (FSC) system for detecting rapidity gaps is shown to be adequate for the proposed studies. With this detector arrangement, valuable new data can be obtained by tagging central diffractive processes.
Laemsae, J W; Orava, R, E-mail: risto.orava@helsinki.fi [Helsinki Insitute of Physics, and Division of Elementary Particle Physics, Department of Physics, PL 64 (Gustaf Haellstroeminkatu 2a), FI-00014 University of Helsinki (Finland)
2011-02-01
The ALICE experiment is shown to be well suited for studies of exclusive final states from central diffractive reactions. The gluon-rich environment of the central system allows detailed QCD studies and searches for exotic meson states, such as glueballs, hybrids and new charmonium-like states. It would also provide a good testing ground for detailed studies of heavy quarkonia. Due to its central barrel performance, ALICE can accurately measure the low-mass central systems with good purity. The efficiency of the Forward Multiplicity Detector (FMD) and the Forward Shower Counter (FSC) system for detecting rapidity gaps is shown to be adequate for the proposed studies. With this detector arrangement, valuable new data can be obtained by tagging central diffractive processes.
Denisov, D V; Miedema, D M; Nienhuis, B; Schall, P
2015-11-01
Using the totally asymmetric simple-exclusion-process and mean-field transport theory, we investigate the transport in closed random networks with simple crossing topology-two incoming, two outgoing segments, as a model for molecular motor motion along biopolymer networks. Inspired by in vitro observation of molecular motor motion, we model the motor behavior at the intersections by introducing different exit rates for the two outgoing segments. Our simulations of this simple network reveal surprisingly rich behavior of the transport current with respect to the global density and exit rate ratio. For asymmetric exit rates, we find a broad current plateau at intermediate motor densities resulting from the competition of two subnetwork populations. This current plateau leads to stabilization of transport properties within such networks. PMID:26651730
Denisov, D. V.; Miedema, D. M.; Nienhuis, B.; Schall, P.
2015-11-01
Using the totally asymmetric simple-exclusion-process and mean-field transport theory, we investigate the transport in closed random networks with simple crossing topology—two incoming, two outgoing segments, as a model for molecular motor motion along biopolymer networks. Inspired by in vitro observation of molecular motor motion, we model the motor behavior at the intersections by introducing different exit rates for the two outgoing segments. Our simulations of this simple network reveal surprisingly rich behavior of the transport current with respect to the global density and exit rate ratio. For asymmetric exit rates, we find a broad current plateau at intermediate motor densities resulting from the competition of two subnetwork populations. This current plateau leads to stabilization of transport properties within such networks.
Ito, Hidetaka
2014-01-01
Interaction between vehicles and pedestrians is seen in many areas such as crosswalks and intersections. In this paper, we study a totally asymmetric simple exclusion process with a bottleneck at a boundary caused by an interaction. Due to the time-dependent effect originating from the speed of pedestrians, the flow of the model varies even if the average hopping probability at the last site is the same. We analyze the phenomenon by using two types of approximations: (2+1)-cluster approximation and isolated rarefaction wave approximation. The approximate results capture intriguing features of the model. Moreover, we discuss the situation where vehicles turn right at the intersection by adding a traffic light at the boundary condition. The result suggests that pedestrian scrambles are valid to eliminate traffic congestion in the right turn lane.
Ito, Hidetaka; Nishinari, Katsuhiro
2014-04-01
Interaction between vehicles and pedestrians is seen in many areas such as crosswalks and intersections. In this paper, we study a totally asymmetric simple exclusion process with a bottleneck at a boundary caused by an interaction. Due to the time-dependent effect originating from the speed of pedestrians, the flow of the model varies even if the average hopping probability at the last site is the same. We analyze the phenomenon by using two types of approximations: extended two-cluster approximation and isolated rarefaction wave approximation. The approximate results capture intriguing features of the model. Moreover, we discuss the situation where vehicles turn right at the intersection by adding a traffic light at the boundary condition. The result suggests that pedestrian scrambles are valid to eliminate traffic congestion in the right-turn lane.
Central limit theorems for multivariate semi-Markov sequences and processes, with applications
Ball, Frank
1999-01-01
In this paper, central limit theorems for multivariate semi-Markov sequences and processes are obtained, both as the number of jumps of the associated Markov chain tends to infinity and, if appropriate, as the time for which the process has been running tends to infinity. The theorems are widely applicable since many functions defined on Markov or semi-Markov processes can be analysed by exploiting appropriate embedded multivariate semi-Markov sequences. An application to a ...
Process as Content in Computer Science Education: Empirical Determination of Central Processes
Zendler, A.; Spannagel, C.; Klaudt, D.
2008-01-01
Computer science education should not be based on short-term developments but on content that is observable in multiple domains of computer science, may be taught at every intellectual level, will be relevant in the longer term, and is related to everyday language and/or thinking. Recently, a catalogue of "central concepts" for computer science…
Central Exclusive π+π− Production in pp̄ Collisions at √s = 0.9 and 1.96 TeV at the Tevatron
Żurek Maria
2014-01-01
Full Text Available Exclusive π+π− production in proton-antiproton collisions at √s = 0.9 and 1.96 TeV in the Collider Detector at Fermilab has been measured. We selected events with exactly two particles with oposite charge, in |η| < 1.3, with no other particles detected in |η| < 5.9. We require the central π+π− to have rapidity |y| < 1. Since these events are dominated by double pomeron exchange, the quantum numbers of the central state are constrained. The data show resonance structures attributed to the f0 and f2 mesons.
Analytic coupling and Sudakov effects in exclusive processes: pion and γ*γ→π0 form factors
We develop and discuss in technical detail an infrared-finite factorization and optimized renormalization scheme for calculating exclusive processes, which enables the inclusion of transverse degrees of freedom without entailing suppression of calculated observables, like form factors. This is achieved by employing an analytic, i.e., infrared stable, running strong-coupling αs(Q2) which removes the Landau singularity at Q2=ΛQCD2 by a minimum power-behaved correction. The ensuing contributions to the cusp anomalous dimension - related to the Sudakov form factor - and to the quark anomalous dimension - which controls evolution - lead to an enhancement at high Q2 of the hard part of exclusive amplitudes, calculated in perturbative QCD, while simultaneously improving its scaling behavior. The phenomenological implications of this framework are analyzed by applying it to the pion's electromagnetic form factor, including the NLO contribution to the hard-scattering amplitude, and also to the pion-photon transition at LO. For the pion wave function, an improved ansatz of the Brodsky-Huang-Lepage type is employed, which includes an effective (constituent-like) quark mass, mq=0.33 GeV. Predictions for both form factors are presented and compared to the experimental data, applying Brodsky-Lepage-Mackenzie commensurate scale setting. We find that the perturbative hard part prevails at momentum transfers above about 20 GeV2, while at lower Q2 values the pion form factor is dominated by Feynman-type contributions. The theoretical prediction for the γ*γ→π0 form factor indicates that the true pion distribution amplitude may be somewhat broader than the asymptotic one. (orig.)
Examining the central and peripheral processes of written word production through meta-analysis
Jeremy ePurcell
2011-10-01
Full Text Available Producing written words requires central cognitive processes (such as orthographic long-term and working memory as well as more peripheral processes responsible for generating the motor actions needed for producing written words in a variety of formats (handwriting, typing, etc.. In recent years, various functional neuroimaging studies have examined the neural substrates underlying the central and peripheral processes of written word production. This study provides the first quantitative meta-analysis of these studies by applying Activation Likelihood Estimation methods (Turkeltaub et al., 2002. For alphabet languages, we identified 11 studies (with a total of 17 experimental contrasts that had been designed to isolate central and/or peripheral processes of word spelling (total number of participants = 146. Three ALE meta-analyses were carried out. One involved the complete set of 17 contrasts; two others were applied to subsets of contrasts to distinguish the neural substrates of central from peripheral processes. These analyses identified a network of brain regions reliably associated with the central and peripheral processes of word spelling. Among the many significant results, is the finding that the regions with the greatest correspondence across studies were in the left inferior temporal/fusiform gyri and left inferior frontal gyrus. Furthermore, although the angular gyrus has traditionally been identified as a key site within the written word production network, none of the meta-analyses found it to be a consistent site of activation, identifying instead a region just superior/medial to the left angular gyrus in the left posterior intraparietal sulcus. In general these meta-analyses and the discussion of results provide a valuable foundation upon which future studies that examine the neural basis of written word production can build.
Herrera, G.; J. C. Davalillo; J. Mulas; Cooksley, G.; O. Monserrat; V. Pancioli
2009-01-01
In this paper the Stable Point Network technique, an established Persistent Scatterer InSAR (PSI) technique, (SPN), has been applied for the first time to the analysis of several geomorphological processes present in the Gállego river basin (Central Pyrenees, Spain). The SPN coherence based approach has been used to process three different SAR images datasets covering two temporal periods: 1995 to 2001 and 2001 to 2007. This approach has permitted the detection of more than 40 000 natural gro...
Preliminary design review package for the solar heating and cooling central data processing system
1976-01-01
The Central Data Processing System (CDPS) is designed to transform the raw data collected at remote sites into performance evaluation information for assessing the performance of solar heating and cooling systems. Software requirements for the CDPS are described. The programming standards to be used in development, documentation, and maintenance of the software are discussed along with the CDPS operations approach in support of daily data collection and processing.
NLO corrections to $\\chi_{bJ}$ two-body exclusive decay processes
Chen, Long-Bin
2014-01-01
The next-to-leading order QCD corrections for $\\chi_{bJ}$, the p-wave bottomonium, to $J/\\psi$ pair decay processes were evaluated utilizing NRQCD factorization formalism. It was determined that the scale dependence was depressed with NLO corrections, and hence the uncertainties in the leading order results were greatly reduced. The total branch ratios were found to be the order of $10^{-5}$ for all three $\\chi_{bJ}\\rightarrow J/\\psi J/\\psi$ processes,indicating that they were observable in the LHC and super-B experiments.
Anthea Vogl
2016-03-01
Full Text Available State-based processes for determining refugee claims are crucial sites of inclusion or exclusion for onshore refugee applicants. This paper argues that cultures of disbelief and exclusion towards onshore refugee applicants are increasingly being enacted indirectly, via procedural reforms to Refugee Status Determination (RSD, which limit the ability of applicants to establish and articulate their claims. Focusing on Australia and Canada, this paper tracks the acceleration and truncation of RSD procedures, which first reflect and then frequently achieve the exclusion of onshore applicants. Two sets of reforms in particular have profoundly limited the terms on which applicants may present their claims. In Canada, this occurred as the result of a major overhaul of RSD that took place in December 2012. In Australia, the policy of ‘enhanced screening’ of applicants achieves the immediate screening-out of certain claims from the Australian determination system. Alongside analysing these reforms as a means of exclusion, this paper argues that the new procedures most disadvantage applicants making claims on the basis of gender-related persecution. Los procesos estatales para resolver las concesiones de asilo son situaciones cruciales para la inclusión o exclusión de los solicitantes de asilo una vez están en el territorio de acogida. Este artículo defiende que cada vez más, se está promulgando indirectamente la cultura de la desconfianza y exclusión hacia los solicitantes de asilo, a través de reformas procesuales de la Determinación del Estatus de Refugiado (DER, lo que limita la capacidad de los solicitantes para establecer y articular sus demandas de asilo. Centrándose en Australia y Canadá, este artículo realiza un seguimiento de la aceleración y el truncamiento de los procedimientos de DER que primero reflejan y después a menudo consiguen la exclusión de los solicitantes en el propio territorio de acogida. Dos grupos de reformas
The Transition Process: Towards Exclusion or Financial Sufficiency. A French-Irish Comparison.
Grelet, Yvette; Mansuy, Michele; Thomas, Gwenaelle
Data from longitudinal school leavers' surveys in France and Ireland were compared to determine types of transition pathways leading to unsuccessful conclusions. Focus was on outcomes of the transition process for school leavers unemployed five years after leaving and for employed young people whose earnings did not allow them to be financially…
Comparison between the fragmentation processes in central Pb + Ag and Pb + Au collisions
Jouault, B.; Royer, G.; Sebille, F.; Haddad, F.; Lecolley, J.F.
1996-12-31
The fragmentation processes of a medium mass system and of a very massive one formed in central collisions are compared within the Landau-Vlasov model taking into account both the isospin dependence and the two-body residual interactions. The simulations predict the formation of a roughly ellipsoidal source in the central Pb + Ag reactions while, for the Pb + Au system, the fragmentation occurs from an hollow source, the configuration of which being intermediate between bubble-like and toroidal shapes. This difference shapes explain and allow to reproduce semi-quantitatively the two different profiles of the experimental kinetic energy spectra. (authors).
Analysis of hard exclusive scattering processes of the HERMES recoil experiment
Deeply virtual Compton Scattering (DVCS), ep → epγ is the simplest reaction giving indication of generalized parton distributions (GPD) of the nucleon. The DVCS process has the same final state as the Bethe-Heitler process (BH). For this reason the access is taken not through the cross-sections directly but through asymmetries between DVCS events depending on charge and polarization of the 27.6 GeV beam. For the first time the azimuthal asymmetry amplitudes according the charge of the lepton beam are extracted using a kinematically complete reconstruction method at the HERMES experiment. The recoil detector installed in 2006 allows the reconstruction of recoiling protons that completes the measurements of the forward detector to cover almost the complete angle range around the vertex. This approach allows suppressing the background processes by almost a complete magnitude compared to the traditional method using only the information of the forward spectrometer. The analysis of the asymmetries was carried out at different values of the kinematic variables tc' xB and Q2 to investigate the dependence of these variables. This work pushes the limits of the readability of data and shows which periods have been found to be unstable in the data acquisition. It points out the impact of this finding to previous HERMES publications.
Analysis of hard exclusive scattering processes of the HERMES recoil experiment
Brodski, Irina
2014-11-15
Deeply virtual Compton Scattering (DVCS), ep → epγ is the simplest reaction giving indication of generalized parton distributions (GPD) of the nucleon. The DVCS process has the same final state as the Bethe-Heitler process (BH). For this reason the access is taken not through the cross-sections directly but through asymmetries between DVCS events depending on charge and polarization of the 27.6 GeV beam. For the first time the azimuthal asymmetry amplitudes according the charge of the lepton beam are extracted using a kinematically complete reconstruction method at the HERMES experiment. The recoil detector installed in 2006 allows the reconstruction of recoiling protons that completes the measurements of the forward detector to cover almost the complete angle range around the vertex. This approach allows suppressing the background processes by almost a complete magnitude compared to the traditional method using only the information of the forward spectrometer. The analysis of the asymmetries was carried out at different values of the kinematic variables t{sub c'} x{sub B} and Q{sup 2} to investigate the dependence of these variables. This work pushes the limits of the readability of data and shows which periods have been found to be unstable in the data acquisition. It points out the impact of this finding to previous HERMES publications.
Exploring the nucleon structure through GPDs and TDAs in hard exclusive processes
Pire, B; Szymanowski, L; Wagner, J
2011-01-01
Generalized Parton Distributions (GPDs) offer a new way to access the quark and gluon nucleon structure. We review recent progress in this domain, emphasizing the need to supplement the experimental study of deeply virtual Compton scattering by its crossed version, timelike Compton scattering. We also describe the extension of the GPD concept to three quark operators and the relevance of their nucleon to meson matrix elements, namely the transition distribution amplitudes (TDAs) which factorize in backward meson electroproduction and related processes. We discuss the main properties of the TDAs. \\
Lopez, Beatriz; Leekam, Susan R.; Arts, Gerda R. J.
2008-01-01
This study aimed to test the assumption drawn from weak central coherence theory that a central cognitive mechanism is responsible for integrating information at both conceptual and perceptual levels. A visual semantic memory task and a face recognition task measuring use of holistic information were administered to 15 children with autism and 16…
Measurements of exclusive dilepton production at 7 and 8 TeV with the ATLAS detector
Rifki, Othmane; The ATLAS collaboration
2016-01-01
In the absence of forward proton tagging, exclusive processes can be distinguished in the central part of the ATLAS detector exploiting the large rapidity gap in the central region and the absence of charged particles reconstructed in the inner tracking detector. This strategy has been exploited to study the exclusive production of dilepton pairs in the data taken at centreofmass energies of 7 and 8 TeV. A measurement of exclusive production of dileptons (ee and mumu) in 7 TeV pp collisions is presented. The results show significant deviations from the pure QED prediction, which can be explained by photon coherence and proton rescattering effects. A new analysis performed at 8 TeV concentrates on the emu final state to search for the exclusive production of WW boson pairs. Furthermore the analysis is reoptimised to search for the exclusive production of the Higgs boson in the WW* decay channel.
Pediatric central auditory processing disorder showing elevated threshold on pure tone audiogram.
Maeda, Yukihide; Nakagawa, Atsuko; Nagayasu, Rie; Sugaya, Akiko; Omichi, Ryotaro; Kariya, Shin; Fukushima, Kunihiro; Nishizaki, Kazunori
2016-10-01
Central auditory processing disorder (CAPD) is a condition in which dysfunction in the central auditory system causes difficulty in listening to conversations, particularly under noisy conditions, despite normal peripheral auditory function. Central auditory testing is generally performed in patients with normal hearing on the pure tone audiogram (PTA). This report shows that diagnosis of CAPD is possible even in the presence of an elevated threshold on the PTA, provided that the normal function of the peripheral auditory pathway was verified by distortion product otoacoustic emission (DPOAE), auditory brainstem response (ABR), and auditory steady state response (ASSR). Three pediatric cases (9- and 10-year-old girls and an 8-year-old boy) of CAPD with elevated thresholds on PTAs are presented. The chief complaint was difficulty in listening to conversations. PTA showed elevated thresholds, but the responses and thresholds for DPOAE, ABR, and ASSR were normal, showing that peripheral auditory function was normal. Significant findings of central auditory testing such as dichotic speech tests, time compression of speech signals, and binaural interaction tests confirmed the diagnosis of CAPD. These threshold shifts in PTA may provide a new concept of a clinical symptom due to central auditory dysfunction in CAPD. PMID:26922127
Kuan, Hui-Shun
2016-01-01
Motor protein motion on biopolymers can be described by models related to the totally asymmetric simple exclusion process (TASEP). Inspired by experiments on the motion of kinesin-4 motors on antiparallel microtubule overlaps, we analyze a model incorporating the TASEP on two antiparallel lanes with binding kinetics and lane switching. We determine the steady-state motor density profiles using phase plane analysis of the steady-state mean field equations and kinetic Monte Carlo simulations. We focus on the the density-density phase plane, where we find an analytic solution to the mean-field model. By studying the phase space flows, we determine the model's fixed points and their changes with parameters. Phases previously identified for the single-lane model occur for low switching rate between lanes. We predict a new multiple coexistence phase due to additional fixed points that appear as the switching rate increases: switching moves motors from the higher-density to the lower-density lane, causing local jamm...
System design package for the solar heating and cooling central data processing system
1978-01-01
The central data processing system provides the resources required to assess the performance of solar heating and cooling systems installed at remote sites. These sites consist of residential, commercial, government, and educational types of buildings, and the solar heating and cooling systems can be hot-water, space heating, cooling, and combinations of these. The instrumentation data associated with these systems will vary according to the application and must be collected, processed, and presented in a form which supports continuity of performance evaluation across all applications. Overall software system requirements were established for use in the central integration facility which transforms raw data collected at remote sites into performance evaluation information for assessing the performance of solar heating and cooling systems.
Gutierrez Ramirez, Ranulfo; Fernandez Montiel, Manuel Francisco [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)
1999-07-01
Some recent experiences of the Management of Thermal Processes of the Instituto de Investigaciones Electricas (IIE) related to the works on generating power stations of electricity, plants of cogeneration and energy saving are presented. [Spanish] Se presentan algunas experiencias recientes de la Gerencia de Procesos Termicos del Instituto de Investigaciones Electricas (IIE) relacionadas con los trabajos sobre centrales generadoras de electricidad, plantas de cogeneracion y ahorro de energia.
Iliadou, V; Iakovides, S
2003-01-01
Background Psychoacoustics is a fascinating developing field concerned with the evaluation of the hearing sensation as an outcome of a sound or speech stimulus. Neuroaudiology with electrophysiologic testing, records the electrical activity of the auditory pathways, extending from the 8th cranial nerve up to the cortical auditory centers as a result of external auditory stimuli. Central Auditory Processing Disorders may co-exist with mental disorders and complicate diagnosis and outcome. Desi...
Exclusive physics at the LHC with SuperChic 2
Harland-Lang, L.A. [University College London, Department of Physics and Astronomy, London (United Kingdom); Khoze, V.A. [University of Durham, Institute for Particle Physics Phenomenology, Durham (United Kingdom); NRC Kurchatov Institute, Gatchina, Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation); Ryskin, M.G. [NRC Kurchatov Institute, Gatchina, Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation)
2016-01-15
We present a range of physics results for central exclusive production processes at the LHC, using the new SuperChic 2 Monte Carlo event generator. This includes significant theoretical improvements and updates, most importantly a fully differential treatment of the soft survival factor, as well as a greater number of generated processes. We provide an overview of the latest theoretical framework, and consider in detail a selection of final states, namely exclusive 2 and 3 jets, photoproduced vector mesons, two-photon initiated muon and W boson pairs and heavy χ{sub c,b} quarkonia. (orig.)
Exclusive physics at the LHC with SuperChic 2
Harland-Lang, L. A., E-mail: l.harland-lang@ucl.ac.uk [Department of Physics and Astronomy, University College London, WC1E 6BT, London (United Kingdom); Khoze, V. A. [Institute for Particle Physics Phenomenology, University of Durham, DH1 3LE, Durham (United Kingdom); Petersburg Nuclear Physics Institute, NRC Kurchatov Institute, Gatchina, 188300, St. Petersburg (Russian Federation); Ryskin, M. G. [Petersburg Nuclear Physics Institute, NRC Kurchatov Institute, Gatchina, 188300, St. Petersburg (Russian Federation)
2016-01-06
We present a range of physics results for central exclusive production processes at the LHC, using the new SuperChic 2 Monte Carlo event generator. This includes significant theoretical improvements and updates, most importantly a fully differential treatment of the soft survival factor, as well as a greater number of generated processes. We provide an overview of the latest theoretical framework, and consider in detail a selection of final states, namely exclusive 2 and 3 jets, photoproduced vector mesons, two-photon initiated muon and W boson pairs and heavy χ{sub c,b} quarkonia.
Central Data Processing System (CDPS) user's manual: Solar heating and cooling program
1976-01-01
The software and data base management system required to assess the performance of solar heating and cooling systems installed at multiple sites is presented. The instrumentation data associated with these systems is collected, processed, and presented in a form which supported continuity of performance evaluation across all applications. The CDPS consisted of three major elements: communication interface computer, central data processing computer, and performance evaluation data base. Users of the performance data base were identified, and procedures for operation, and guidelines for software maintenance were outlined. The manual also defined the output capabilities of the CDPS in support of external users of the system.
Cameron, Sharon; Glyde, Helen; Dillon, Harvey; King, Alison; Gillies, Karin
2015-11-01
This article describes the development and evaluation of a national service to diagnose and remediate central auditory processing disorder (CAPD). Data were gathered from 38 participating Australian Hearing centers over an 18-month period from 666 individuals age 6, 0 (years, months) to 24, 8 (median 9, 0). A total of 408 clients were diagnosed with either a spatial processing disorder (n = 130), a verbal memory deficit (n = 174), or a binaural integration deficit (n = 104). A hierarchical test protocol was used so not all children were assessed on all tests in the battery. One hundred fifty clients decided to proceed with deficit-specific training (LiSN & Learn or Memory Booster) and/or be fitted with a frequency modulation system. Families were provided with communication strategies targeted to a child's specific listening difficulties and goals. Outcomes were measured using repeat assessment of the relevant diagnostic test, as well as the Client Oriented Scale of Improvement measure and Listening Inventories for Education teacher questionnaire. Group analyses revealed significant improvements postremediation for all training/management options. Individual posttraining performance and results of outcome measures also are discussed. PMID:27587910
Bangsø Nielsen, Henrik; Angelidaki, Irini
2008-01-01
The present study focuses on process imbalances in Danish centralized biogas plants treating manure in combination with industrial waste. Collection of process data from various full-scale plants along with a number of interviews showed that imbalances occur frequently. High concentrations of...... conditions) and high fractions of industrial waste in the feedstock was also observed. The process imbalances and suboptimal conditions are mainly allowed to occur due to 1) inadequate knowledge about the waste composition, 2) inadequate knowledge about the waste degradation characteristics, 3) inadequate...... process surveillance, especially with regard to volatile fatty acids, and 4) insufficient pre-storage capacity causing inexpedient mixing and hindering exact dosing of the different waste products....