Wissel, S.
2006-10-15
In this thesis we investigate thermal in-medium modifications of various mesonic correlation functions by lattice simulations of Quantum Chromodynamics for light valence quark masses and vanishing chemical potential. Mesonic properties are typically extracted from spatial correlation functions. The results presented are based on quenched gauge field configurations generated with the standard Wilson plaquette gauge action. Concerning the fermionic part of the action, we use the non-perturbative O(a) improved Sheikholeslami-Wohlert as well as the truncated hypercube perfect action. Furthermore we utilize the maximum entropy method in order to determine physically relevant pole masses and to investigate thermal modifications of physical states and possible lattice artefacts in the interacting case. The analyses of pole and screening masses, dispersion relations, wave functions, decay constants and spectral functions essentially yield no significant modifications of the zero-temperature behavior up to 0.55 T{sub c}. Close to the phase transition in-medium effects seem to appear, which lead inter alia to significant differences between pole and screening masses. The decay constants are in good agreement with the experimental values. We have simulated above T{sub c} at nearly zero quark masses. At 1.24 T{sub c}, the occurrence of topological effects, a sign for the presence of a still broken U(1){sub A} symmetry, prevent a more thorough analyses close to the phase transition. A complete continuum and infinite volume extrapolation of screening masses, guided by free lattice effective masses is done. It shows that the presence of collective phenomena at 1.5 and 3 T{sub c} cannot be explained by pure lattice artefacts. Unlike the vector meson the pion is far from being considered an unbound state. (orig.)
Wissel, S.
2006-10-01
In this thesis we investigate thermal in-medium modifications of various mesonic correlation functions by lattice simulations of Quantum Chromodynamics for light valence quark masses and vanishing chemical potential. Mesonic properties are typically extracted from spatial correlation functions. The results presented are based on quenched gauge field configurations generated with the standard Wilson plaquette gauge action. Concerning the fermionic part of the action, we use the non-perturbative O(a) improved Sheikholeslami-Wohlert as well as the truncated hypercube perfect action. Furthermore we utilize the maximum entropy method in order to determine physically relevant pole masses and to investigate thermal modifications of physical states and possible lattice artefacts in the interacting case. The analyses of pole and screening masses, dispersion relations, wave functions, decay constants and spectral functions essentially yield no significant modifications of the zero-temperature behavior up to 0.55 T c . Close to the phase transition in-medium effects seem to appear, which lead inter alia to significant differences between pole and screening masses. The decay constants are in good agreement with the experimental values. We have simulated above T c at nearly zero quark masses. At 1.24 T c , the occurrence of topological effects, a sign for the presence of a still broken U(1) A symmetry, prevent a more thorough analyses close to the phase transition. A complete continuum and infinite volume extrapolation of screening masses, guided by free lattice effective masses is done. It shows that the presence of collective phenomena at 1.5 and 3 T c cannot be explained by pure lattice artefacts. Unlike the vector meson the pion is far from being considered an unbound state. (orig.)
Meson Correlators in Finite Temperature Lattice QCD
De Forcrand, Philippe; Hashimoto, T; Hioki, S; Matsufuru, H; Miyamura, O; Nakamura, A; Takaishi, T; Umeda, T; Stamatescu, I O; CERN. Geneva; Forcrand, Ph. de
2001-01-01
We analyze temporal and spatial meson correlators in quenched lattice QCD at T>0. Below T_c we observe little change in the meson properties as compared with T=0. Above T_c we observe new features: chiral symmetry restoration and signals of plasma formation, but also indication of persisting mesonic (metastable) states and different temporal and spatial masses in the mesonic channels. This suggests a complex picture of QGP in the region 1 - 1.5 T_c.
Meson spectral functions at finite temperature
Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S.
2001-10-01
The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T c . The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64) 3 x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature. (orig.)
Meson spectral functions at finite temperature
Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S.
2002-01-01
The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T c . The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64) 3 x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature
Meson spectral functions at finite temperature
Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S
2002-03-01
The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T{sub c}. The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64){sup 3} x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature.
Meson spectral functions at finite temperature
Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S. [Bielefeld Univ. (Germany). Fakultaet fuer Physik
2001-10-01
The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T{sub c}. The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64){sup 3} x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature. (orig.)
In-medium meson properties and screening correlators
Bazavov, A; Karsch, F; Mukherjee, Swagato; Petreczky, P; Maezawa, Y
2014-01-01
We study spatial meson correlation functions consisting of strange quarks, strange and charm quarks and charm quarks in (2 + 1)-flavor QCD using the highly improved staggered quark action. We find that the in-medium modification of the meson correlators decreases with increasing charm quark content and decreasing size. In particular, we find strong in-medium modification of φ and D s meson correlators around the chiral transition temperature T c , while J/ψ and η c correlators show strong in-medium modification only at temperatures of 1.4T c .
Meson-induced correlations of nucleons in nuclear Compton scattering
Huett, M.; Milstein, A.I.
1998-01-01
The nonresonant (seagull) contribution to the nuclear Compton amplitude at low energies is strongly influenced by nucleon correlations arising from meson exchange. We study this problem in a modified Fermi gas model, where nuclear correlation functions are obtained with the help of perturbation theory. The dependence of the mesonic seagull amplitude on the nuclear radius is investigated and the influence of a realistic nuclear density on this amplitude is discussed. We found that different form factors appear for the static part (proportional to the enhancement constant κ) of the mesonic seagull amplitude and for the parts, which contain the contribution from electromagnetic polarizabilities. copyright 1998 The American Physical Society
Integral transform technique for meson wave functions
Bakulev, A.P.; Mikhajlov, S.V.
1996-01-01
In a recent paper [1] we proposed a new approach for extracting the wave function of the π-meson φ π (x) and the masses and wave functions of its first resonances from the new QCD sum rules for nondiagonal correlators obtained in [2]. Here, we test our approach using an exactly solvable toy model as an illustrating example. We demonstrate the validity of the method and suggest a pure algebraic procedure for extracting the masses and wave functions relating to the case under investigation. We also explore the stability of the procedure under perturbations of the theoretical part of the sum rule. In application to the pion case, this results not only in the mass and wave function of the first resonance (π'), but also in the estimation of π''-mass. 17 refs., 11 figs
Suppression and Two-Particle Correlations of Heavy Mesons in Heavy-Ion Collisions
Cao, Shanshan [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Qin, Guang-You [Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE), Central China Normal University, Wuhan, 430079 (China); Bass, Steffen A. [Department of Physics, Duke University, Durham, NC 27708 (United States)
2016-12-15
We study the medium modification of heavy quarks produced in heavy-ion collisions. The evolution of heavy quarks inside the QGP is described using a modified Langevin framework that simultaneously incorporates their collisional and radiative energy loss. Within this framework, we provide good descriptions of the heavy meson suppression and predictions for the two-particle correlation functions of heavy meson pairs.
Meson wave functions in 2-dim QCD
Hildebrandt, S.; Visnjic, V.
1977-07-01
We consider the eigenvalue problem of 't Hooft for the meson spectrum in 2-dim QCD by defining some alternative formulations whose equivalence we prove. Hence we are able to prove that the spectrum is discrete and of finite multiplicity and to derive bounds (upper and lower) for the eigenvalues (ground state, with state and n → infinitely state). We prove that the functions are analytic and use this to carry out explicit numerical calculations of the wave functions for various values of the quark masses and to recalculate the meson spectrum. (orig.) [de
Correlation function distributions in rapidity for pairs of π mesons in K-p interactions at 32 GeV/c
Bumazhnov, V.A.; Babintsev, V.V.; Bogolyubskij, M.Yu.
1983-01-01
The inclusive and semiinclusiVe distributions of correlation functions in K - p-interactions at 32 GeV/c are presented as functions of rapidity. The positive short range correlations among rapidities of two charged pions reach maximUm in fragmentation ranges of incoming hadrons. The correlations become central and increase with rising of transverse momentum. Maximum values of correlations in the π + π - and π - π - systems oc in the region of negative and positive values of rasidity
Study of temporal quantum correlations in decohering B and K meson systems
Naikoo, Javid; Alok, Ashutosh Kumar; Banerjee, Subhashish
2018-03-01
In this work we study temporal quantum correlations, quantified by Leggett-Garg (LG) and LG-type inequalities, in the B and K meson systems. We use the tools of open quantum systems to incorporate the effect of decoherence which is quantified by a single phenomenological parameter. The effect of C P violation is also included in our analysis. We find that the LG inequality is violated for both B and K meson systems, the violation being most prominent in the case of K mesons and least for Bs system. Since the systems with no coherence do not violate LGI, incorporating decoherence is expected to decrease the extent of violation of LGI and is clearly brought out in our results. We show that the expression for the LG functions depends upon an additional term, apart from the experimentally measurable meson transition probabilities. This term vanishes in the limit of zero decoherence. On the other hand, the LG-type parameter can be directly expressed in terms of transition probabilities, making it a more appropriate observable for studying temporal quantum correlations in neutral meson systems.
Inclusive rapidity correlations of π- mesons in pp interactions
Golokhvastov, A.I.
1994-01-01
The simple single-parameter approximation of one-particle semi-inclusive rapidity distributions of negative particles (π - mesons) in pp interactions at various multiplicities over the investigated range of primary momenta 6.6 -400 GeV/c is presented. Assuming the lack of any kind of correlations in semi-inclusive events, a good description of experimental data on two-particle inclusive rapidity correlations (pseudocorrelations) is obtained. Data on forward-backward, right-left correlations and multiplicity distributions in rapidity intervals and intervals separated by empty gaps do not contradict independent π - production either. (orig.)
Rapidity resummation for B-meson wave functions
Shen Yue-Long
2014-01-01
Full Text Available Transverse-momentum dependent (TMD hadronic wave functions develop light-cone divergences under QCD corrections, which are commonly regularized by the rapidity ζ of gauge vector defining the non-light-like Wilson lines. The yielding rapidity logarithms from infrared enhancement need to be resummed for both hadronic wave functions and short-distance functions, to achieve scheme-independent calculations of physical quantities. We briefly review the recent progress on the rapidity resummation for B-meson wave functions which are the key ingredients of TMD factorization formulae for radiative-leptonic, semi-leptonic and non-leptonic B-meson decays. The crucial observation is that rapidity resummation induces a strong suppression of B-meson wave functions at small light-quark momentum, strengthening the applicability of TMD factorization in exclusive B-meson decays. The phenomenological consequence of rapidity-resummation improved B-meson wave functions is further discussed in the context of B → π transition form factors at large hadronic recoil.
The effect of meson wave function on heavy-quark fragmentation function
Moosavi Nejad, S.M. [Yazd University, Faculty of Physics (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, Tehran (Iran, Islamic Republic of)
2016-05-15
We calculate the process-independent fragmentation functions (FFs) for a heavy quark to fragment into heavy mesons considering the effects of meson wave function. In all previous works, where the FFs of heavy mesons or heavy baryons were calculated, a delta function form was approximated for the wave function of hadrons. Here, for the first time, we consider a typical mesonic wave function which is different from the delta function and is the nonrelativistic limit of the solution of Bethe-Salpeter equation with the QCD kernel. We present our numerical results for the heavy FFs and show how the proposed wave function improves the previous results. As an example, we focus on the fragmentation function for c-quark to split into S-wave D{sup 0} -meson and compare our results with experimental data from BELLE and CLEO. (orig.)
Subtracted Dispersion Relations for In-medium Meson Correlators in QCD Sum Rules
Florkowski, W; Broniowski, W [The H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland)
1999-01-01
We analyze subtracted dispersion relations for meson correlators at finite baryon density and temperature. Such relations are needed for QCD sum rules. We point out that importance of scattering terms, as well as finite, well-defined subtraction constants. Both are necessary for consistency, in particular for the equality of the longitudinal and transverse correlators in the limit of the vanishing three-momentum of mesons relative to the medium. We present detailed calculations in various mesonic channels of the Fermi gas of nucleons. (author)
Nondiffraction photoproduction of vector mesons and the photon structure function
Badalyan, R.G.; Gulkanyan, H.R.
1988-01-01
In the framework of the recombination model of hadron production a self-consistent description of the available data on the inclusive spectra of the nondiffraction photoproduction of vector mesons in the fragmentation region of photons at high energies is obtained. The parameters of parton distribution in the hadron component of a photon are estimated and its structure is compared with the measurements of the photon structure function in γγ-interactions at low Q 2 . 15 refs.; 2 figs.; 1 tab
Off-shell pairing correlations from meson-exchange theory of nuclear forces
Sedrakian, Armen
2003-01-01
We develop a model of off-mass-shell pairing correlations in nuclear systems, which is based on the meson-exchange picture of nuclear interactions. The temporal retardations in the model are generated by the Fock-exchange diagrams. The kernel of the complex gap equation for baryons is related to the in-medium spectral function of mesons, which is evaluated nonperturbatively in the random phase approximation. The model is applied to the low-density neutron matter in neutron star crusts by separating the interaction into a long-range one-pion-exchange component and a short-range component parametrized in terms of Landau Fermi liquid parameters. The resulting Eliashberg-type coupled nonlinear integral equations are solved by an iterative procedure. We find that the self-energies extend to off-shell energies of the order of several tens of MeV. At low energies the damping of the neutron pair correlations due to the coupling to the pionic modes is small, but becomes increasingly important as the energy is increased. We discuss an improved quasiclassical approximation under which the numerical solutions are obtained
Melting spectral functions of the scalar and vector mesons in a holographic QCD model
Fujita, Mitsutoshi; Kikuchi, Toru; Fukushima, Kenji; Misumi, Tatsuhiro; Murata, Masaki
2010-01-01
We investigate the finite-temperature spectral functions of heavy quarkonia by using the soft-wall anti-de Sitter/QCD model. We discuss the scalar, the pseudoscalar, the vector, and the axial-vector mesons and compare their qualitative features of the melting temperature and growing width. We find that the axial-vector meson melts earlier than the vector meson, while there appears only a slight difference between the scalar and pseudoscalar mesons, which also melt earlier than the vector meson.
Can strong correlations be experimentally revealed for Ҡ -mesons?
Hiesmayr Beatrix C.
2014-01-01
Full Text Available In 1964 the physicists John St. Bell working at CERN took the 1935-idea of Einstein-Podolsky-Rosen seriously and found that all theories based on local realism have to satisfy a certain inequality, nowadays dubbed Bell’s inequality. Experiments with ordinary matter systems or light show violations of Bell’s inequality favouring the quantum theory though a loophole free experiment has not yet been performed. This contribution presents an experimentally feasible Bell inequality for systems at higher energy scales, i.e. entangled neutral Ҡ -meson pairs that are typically produced in Φ -mesons decays or proton-antiproton annihilation processes. Strong requirements have to be overcome in order to achieve a conclusive tests, such a proposal was recently published. Surprisingly, this new Bell inequality reveals new features for weakly decaying particles, in particular, a strong sensitivity to the combined charge-conjugation-parity (CP symmetry. Here-with, a puzzling relation between a symmetry breaking for mesons and Bell’s inequality—which is a necessary and sufficient condition for the security of quantum cryptography protocols— is established. This becomes the more important since CP symmetry is related to the cosmological question why the antimatter disappeared after the Big Bang.
Lifetime of rho meson in correlation with magnetic-dimensional reduction
Kawaguchi, Mamiya [Nagoya University, Department of Physics, Nagoya (Japan); Matsuzaki, Shinya [Nagoya University, Department of Physics, Nagoya (Japan); Nagoya University, Institute for Advanced Research, Nagoya (Japan)
2017-04-15
It is naively expected that in a strong magnetic configuration, the Landau quantization ceases the neutral rho meson to decay to the charged pion pair, so the neutral rho meson will be long-lived. To closely access this naive observation, we explicitly compute the charged pion loop in the magnetic field at the one-loop level, to evaluate the magnetic dependence of the lifetime for the neutral rho meson as well as its mass. Due to the dimensional reduction induced by the magnetic field (violation of the Lorentz invariance), the polarization (spin s{sub z} = 0, ±1) modes of the rho meson, as well as the corresponding pole mass and width, are decomposed in a nontrivial manner compared to the vacuum case. To see the significance of the reduction effect, we simply take the lowest Landau level approximation to analyze the spin-dependent rho masses and widths. We find that the ''fate'' of the rho meson may be more complicated because of the magnetic-dimensional reduction: as the magnetic field increases, the rho width for the spin s{sub z} = 0 starts to develop, reaches a peak, then vanishes at the critical magnetic field to which the folklore refers. On the other side, the decay rates of the other rhos for s{sub z} = ±1 monotonically increase as the magnetic field develops. The correlation between the polarization dependence and the Landau level truncation is also addressed. (orig.)
Inclusive D* Meson Cross Sections and D* Jet Correlations in Photoproduction at HERA
Aktas, A.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J.C.; Boenig, M.O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Caron, S.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J.G.; Coughlan, J.A.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; de Boer, Y.; Delcourt, B.; Del Degan, M.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkewicz, A.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Flucke, G.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerlich, C.; Ghazaryan, Samvel; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B.R.; Grindhammer, G.; Gwilliam, C.; Habib, S.; Haidt, D.; Hansson, M.; Heinzelmann, G.; Henderson, R.C.W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Hussain, S.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, Andreas Werner; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.I.; Lueders, H.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Marage, P.; Marshall, R.; Marti, L.; Martisikova, M.; Martyn, H.U.; Maxfield, S.J.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mladenov, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, T.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Papadopoulou, T.; Pascaud, C.; Patel, G.D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Placakyte, R.; Portheault, B.; Povh, B.; Prideaux, P.; Rahmat, A.J.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D.P.C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.C.; Sefkow, F.; Shaw-West, R.N.; Sheviakov, I.; Shtarkov, L.N.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Steder, M.; Stella, B.; Stiewe, J.; Stoilov, A.; Straumann, U.; Sunar, D.; Tchoulakov, V.; Thompson, G.; Thompson, P.D.; Toll, T.; Tomasz, F.; Traynor, D.; Trinh, T.N.; Truoel, P.; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Urban, Marcel; Usik, A.; Utkin, D.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vinokurova, S.; Volchinski, V.; Wacker, K.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wessling, B.; Wissing, C.; Wolf, R.; Wunsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y.C.; Zimmermann, J.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.
2007-01-01
Differential photoproduction cross sections are measured for events containing D* mesons. The data were taken with the H1 detector at the ep collider HERA and correspond to an integrated luminosity of 51.1 pb-1. The kinematic region covers small photon virtualities Q^2 < 0.01 GeV^2 and photon-proton centre-of-mass energies of 171 < W_gammap < 256 GeV. The details of the heavy quark production process are further investigated in events with one or two jets in addition to the D* meson. Differential cross sections for D* jet production are determined and the correlations between the D* meson and the jet(s) are studied. The results are compared with perturbative QCD predictions applying collinear- or kt -factorisation.
On wave functions of mesons involving the s-, c- and b-quarks
Zhitnitskij, A.R.; Zhitnitskij, I.R.; Chernyak, V.L.
1983-01-01
The wave function components of pseudoscalar and vestor mesons which are antisymmertric with respect to permutation of the quark momenta are studied. The results are as follows: elt xsub(s)-xsub(u) > sub(K) approximately equal to 0.11 for the K meson, sub(K*) approximately equal to 0.15-C.20 for the K* meson, being a mean fraction of the longitudinal momentum transferred by the s(u) quark. The following estimates are obtained: / approximately equal to 0.20-0.25; / approximately equal to 0.8x10 -2 . The asymptotics of the K 0 -meson form factor and the etasub(c) → KK* decay width are found. Properties of the wave functions of mesons which contain a light and a heavy quark (D, B, ...) are considered. For the B 0 meson approximately equal to 0.10 is found. Arguments are given supporting nonenhancement of the amplitudes of the processes involving D mesons compared to similar K-meson amplitudes. A simple way is suggested to determine the asymptotic form of various wave functions
Correlations between D and D-bar mesons in high energy photoproduction
Gottschalk, Erik E.; Link, J.; Reyes, M.; Yager, P.M.; Anjos, J.; Bediaga, I.; Gobel, C.; Magnin, J.; Massafferri, A.; Miranda, J.M. de; Pepe, I.M.; Reis, A.C. dos; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sanchez-Hernandez, A.; Uribe, C.; Vasquez, F.; Agostino, L.; Cinquini, L.; Cumalat, J.P.; O'Reilly, B.; Ramirez, J.E.; Segoni, I.; Butler, J.N.; Cheung, H.W.K.; Chiodini, G.; Gaines, I.; Garbincius, P.H.; Garren, L.A.; Gottschalk, E.E.; Kasper, P.H.; Kreymer, A.E.; Kutschke, R.; Benussi, L.; Bianco, S.; Fabbri, F.L.; Zallo, A.; Cawlfield, C.; Kim, D.Y.; Park, K.S.; Rahimi, A.; Wiss, J.; Gardner, R.; Kryemadhi, A.; Chang, K.H.; Chung, Y.S.; Kang, J.S.; Ko, B.R.; Kwak, J.W.; Lee, K.B.; Cho, K.; Park, H.; Alimonti, G.; Barberis, S.; Cerutti, A.; Boschini, M.; D'Angelo, P.; DiCorato, M.; Dini, P.; Edera, L.; Erba, S.; Giammarchi, M.; Inzani, P.; Leveraro, F.; Malvezzi, S.; Menasce, D.; Mezzadri, M.; Moroni, L.; Pedrini, D.; Pontoglio, C.; Prelz, F.; Rovere, M.; Sala, S.; Davenport, T.F.; Arena, V.; Boca, G.; Bonomi, G.; Gianini, G.; Liguori, G.; Merlo, M.M.; Pantea, D.; Ratti, S.P.; Vitulo, P.; Hernandez, H.; Lopez, A.M.; Mendez, H.; Mendez, L.; Montiel, E.; Olaya, D.; Paris, A.; Quinones, J.; Rivera, C.; Xiong, W.; Zhang, Y.; Wilson, J.R.; Handler, T.; Mitchell, R.; Engh, D.; Hosack, M.; Johns, W.E.; Nehring, M.; Sheldon, P.D.; Stenson, K.; Vaadering, E.W.; Webster, M.; Sheaff, M.
2003-01-01
Over 7000 events containing a fully reconstructed D D-bar pair have been extracted from data recorded by the FOCUS photoproduction experiment at Fermilab. Preliminary results from a study of correlations between D and D-bar mesons are presented. Correlations are used to study perturbative QCD predictions and investigate non-perturbative effects. We also present a preliminary result on the production of Ψ(3770)
Renormalized sum rules for structure functions of heavy meson decays
Grozin, A.G.; Korchemsky, G.P.
1996-01-01
We consider the properties of the structure functions of inclusive heavy meson decays B→X c and treat the c quark mass as a free parameter. We show that in two extreme cases of heavy and light c quarks the structure functions of heavy-heavy and heavy-light transitions are given by a Fourier transform of the matrix elements of Wilson lines containing a timelike and a lightlike segment, correspondingly. Using the renormalization properties of Wilson lines we find the dependence of the structure functions on the factorization scale, the structure function of the heavy-heavy transition is renormalized multiplicatively, while that of the heavy-light transition obeys the GLAP-type evolution equation. We propose a generalization of the sum rules for the moments of the structure functions (Bjorken, Voloshin, and the open-quote open-quote third close-quote close-quote sum rules) with a soft exponential factorization cutoff, which correctly incorporates both perturbative and nonperturbative effects. We analyze nonperturbative corrections by first considering infrared renormalon contributions to the Wilson lines. Uncertainties induced by the leading renormalon pole at u=1/2 are exactly canceled by a similar uncertainty in the heavy quark pole mass. The leading nonperturbative corrections associated with the next renormalon at u=1 are parametrized by the matrix element μ π 2 which is proportional to the heavy quark kinetic energy. copyright 1996 The American Physical Society
Isgur-Wise function for heavy-light mesons in the D-dimensional potential model
Roy, Sabyasachi; Choudhury, D K; Hazarika, B J
2012-01-01
We report the results of a wave function for mesons in D space-time dimension developed by considering the quark-antiquark potential of Nambu-Goto strings. With this wave function, we have studied the Isgur-Wise function for heavy-light mesons and its derivatives such as slope and curvature. The dimensional dependence of our results and a comparative study with the results of three-dimensional QCD are also reported.
Meson and baryon correlation studies using the PEP-TPC/2γ Facility
Ronan, M.T.
1991-03-01
Results on vector meson, and strange and charmed-baryon production are presented for data taken during the period 1982--1986 using the TPC/2γ detector at PEP. Vector mesons (ρ 0 , K * and φ) with 0, 1 and 2 strange quarks are used to obtain redundant measures of strange-quark suppression and of the vector to pseudoscalar ratio in hadronization. Measurements of the production rates of Λ, Ξ - , Ω and Ξ *0 hyperons and for the Λ c and of rapidity correlations between Λ bar Λ pairs provide sensitive tests of baryon production in fragmentation models. In addition, two- and three-particle correlations between like sign pions provide further evidence for the Bose-Einstein effect in e + e - interactions including the relativistic motion of particle sources. 9 refs., 7 figs
Bysted, Tommy Kristensen; Hamila, R.; Gabbouj, M.
1998-01-01
A new correlation function called the Teager correlation function is introduced in this paper. The connection between this function, the Teager energy operator and the conventional correlation function is established. Two applications are presented. The first is the minimization of the Teager error...... norm and the second one is the use of the instantaneous Teager correlation function for simultaneous estimation of TDOA and FDOA (Time and Frequency Difference of Arrivals)....
Soyeur, M.; Brown, G.E.; Rho, M.
1991-01-01
The electromagnetic form factors of nucleons appear dominated by vector mesons at momentum transfers small than ∼ 1 GeV/c. It is therefore expected that measurements of quantities involving the electromagnetic form factors of nucleons embedded in nuclei will be sensitive to changes in vector meson properties arising from their interaction with the medium. Longitudinal and transverse response functions measured in quasi-elastic (e,e'p) reactions provide such data for two very different operators, the charge and the current densities. We show that a decrease of vector meson masses in the medium, consistent with present expectations about chiral symmetry restoration in nuclei, produces the quenching observed in the longitudinal response of light systems ( 3 He, 4 He) and part of this quenching for heavier nuclei 40 Ca where nuclear correlations are expected to generate an additional suppression of the longitudinal response. The transverse response is almost unchanged, in agreement with the data. Difficulties in extrating very quantitative information on the in-medium behaviour of vector mesons from (e,e'p) data are pointed out
Heavy quark fragmentation functions for D-wave quarkonium and charmed beauty mesons
Cheung, K.; Yuan, T.C.
1995-09-01
At the large transverse momentum region, the production of heavy-heavy bound-states such as charmonium, bottomonium, and anti bc mesons in high energy e + e - and hadronic collisions is dominated by parton fragmentation. The authors calculate the heavy quark fragmentation functions into the D-wave quarkonium and anti bc mesons to leading order in the strong coupling constant and in the non-relativistic expansion. In the anti bc meson case, one set of its D-wave states is expected to lie below the open flavor threshold. The total fragmentation probability for a anti b antiquark to split into the D-wave anti bc mesons is about 2 x 10 -5 , which implies that only 2% of the total pseudo-scalar ground state B c comes from the cascades of these orbitally excited states
Baryonic and mesonic 3-point functions with open spin indices
Bali, Gunnar S.; Collins, Sara; Gläßle, Benjamin; Heybrock, Simon; Korcyl, Piotr; Löffler, Marius; Rödl, Rudolf; Schäfer, Andreas
2018-03-01
We have implemented a new way of computing three-point correlation functions. It is based on a factorization of the entire correlation function into two parts which are evaluated with open spin-(and to some extent flavor-) indices. This allows us to estimate the two contributions simultaneously for many different initial and final states and momenta, with little computational overhead. We explain this factorization as well as its efficient implementation in a new library which has been written to provide the necessary functionality on modern parallel architectures and on CPUs, including Intel's Xeon Phi series.
Hot nuclear matter in the modified quark-meson coupling model with quark-quark correlations
Zakout, I.; Jaqaman, H.R.
2000-01-01
Short-range quark-quark correlations in hot nuclear matter are examined within the modified quark-meson coupling (MQMC) model by adding repulsive scalar and vector quark-quark interactions. Without these correlations, the bag radius increases with the baryon density. However, when the correlations are introduced the bag size shrinks as the bags overlap. Also as the strength of the scalar quark-quark correlation is increased, the decrease of the effective nucleon mass M* N with the baryonic density is slowed down and tends to saturate at high densities. Within this model we study the phase transition from the baryon-meson phase to the quark-gluon plasma (QGP) phase with the latter modelled as an ideal gas of quarks and gluons inside a bag. Two models for the QGP bag parameter are considered. In one case, the bag is taken to be medium-independent and the phase transition from the hadron phase to QGP is found to occur at five to eight times ordinary nuclear matter density for temperatures less than 60 MeV. For lower densities, the transition takes place at a higher temperature, reaching up to 130 MeV at zero density. In the second case, the QGP bag parameter is considered to be medium-dependent as in the MQMC model for the hadronic phase. In this case, it is found that the phase transition occurs at much lower densities. (author)
Proton structure function and Bc meson production in γγ collisions
Martynenko, A.P.; Saleev, V.A.
1996-01-01
Using nonrelativistic quark model and perturbative QCD the production of B c (B* c ) mesons via resolved-photon interaction in γγ-collisions is studied. It is shown that the resolved-photon contribution via partionic subprocess cγ→B c (B* c )b is very important both near threshold of the B c (B* c )-meson production, where the hadron-like part of the photon structure function dominates, and at large energies, where only the point-like part of the photon structure function give the contribution increased versus energy. 18 refs., 5 figs
Proper-time resolution function for measurement of time evolution of B mesons at the KEK B-Factory
Tajima, H.; Aihara, H.; Higuchi, T.; Kawai, H.; Nakadaira, T.; Tanaka, J.; Tomura, T.; Yokoyama, M.; Hazumi, M.; Sakai, Y.; Sumisawa, K.; Kawasaki, T.
2004-01-01
The proper-time resolution function for the measurement of the time evolution of B mesons with the Belle detector at KEKB is studied in detail. The obtained resolution function is applied to the measurement of B meson lifetimes, the B0B-bar 0 oscillation frequency and time-dependent CP asymmetries
Pair Correlation Function Integrals
Wedberg, Nils Hejle Rasmus Ingemar; O'Connell, John P.; Peters, Günther H.J.
2011-01-01
We describe a method for extending radial distribution functions obtained from molecular simulations of pure and mixed molecular fluids to arbitrary distances. The method allows total correlation function integrals to be reliably calculated from simulations of relatively small systems. The long......-distance behavior of radial distribution functions is determined by requiring that the corresponding direct correlation functions follow certain approximations at long distances. We have briefly described the method and tested its performance in previous communications [R. Wedberg, J. P. O’Connell, G. H. Peters......, and J. Abildskov, Mol. Simul. 36, 1243 (2010); Fluid Phase Equilib. 302, 32 (2011)], but describe here its theoretical basis more thoroughly and derive long-distance approximations for the direct correlation functions. We describe the numerical implementation of the method in detail, and report...
Lipkin, H. J.
1989-11-01
The Einstein-Podolsky-Rosen effect arises in particle physics when pairs of neutral K, D or B mesons are created in a definite quantum state, and the decays of the two mesons are correlated. Choosing the decay mode to be detected for one of the two mesons creates a 'polarized beam' on the other side which has interesting and usfull properties. Application to nvestigations of CP violation are discussed. (author)
Inclusive D*± meson cross sections and D*±-jet correlations in photoproduction at HERA
Aktas, A.; Andreev, V.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Bruncko, D.; Büsser, F. W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Caron, S.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J. G.; Coughlan, J. A.; Cox, B. E.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Dau, W. D.; Daum, K.; de Boer, Y.; Delcourt, B.; Del Degan, M.; de Roeck, A.; de Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Flucke, G.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerlich, C.; Ghazaryan, S.; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B. R.; Grindhammer, G.; Gwilliam, C.; Habib, S.; Haidt, D.; Hansson, M.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Hussain, S.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Landon, M. P. J.; Lange, W.; Laštovička-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Marage, P.; Marshall, R.; Marti, L.; Martisikova, M.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mladenov, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, T.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Papadopoulou, T.; Pascaud, C.; Patel, G. D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Plačakytė, R.; Portheault, B.; Povh, B.; Prideaux, P.; Rahmat, A. J.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D. P. C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, A.; Steder, M.; Stella, B.; Stiewe, J.; Stoilov, A.; Straumann, U.; Sunar, D.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Toll, T.; Tomasz, F.; Traynor, D.; Trinh, T. N.; Truöl, P.; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Urban, M.; Usik, A.; Utkin, D.; Valkárová, A.; Vallée, C.; van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vinokurova, S.; Volchinski, V.; Wacker, K.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wessling, B.; Wissing, C.; Wolf, R.; Wünsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Žáček, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, J.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.
2007-04-01
Differential photoproduction cross sections are measured for events containing D*± mesons. The data were taken with the H1 detector at the ep collider HERA and correspond to an integrated luminosity of 51.1 pb-1. The kinematic region covers small photon virtualities Q2 < 0.01 GeV2 and photon proton centre-of-mass energies of 171 < Wγ p < 256 GeV. The details of the heavy quark production process are further investigated in events with one or two jets in addition to the D*± meson. Differential cross sections for D*+jet production are determined and the correlations between the D*± meson and the jet(s) are studied. The results are compared with perturbative QCD predictions applying collinear- or kt-factorisation.
The effect of vector meson decays on di-hadron fragmentation functions
Matevosyan, H.H.; Thomas, A.W.; Bentz, W.
2014-01-01
Di-hadron Fragmentation Functions (DFF) provide a vast amount of information on the intricate details of the parton hadronization process. Moreover, they provide a unique access to the 'clean' extraction of nucleon transversity parton distribution functions in semi inclusive deep inelastic two hadron production process with a transversely polarised target. On the example of the u → π + π - we analyse the properties of unpolarized DFFs using their probabilistic interpretation. We use both the NJL-jet hadronization model and PYTHIA 8.1 event generator to explore the effect of the strong decays of the vector mesons produced in the quark hadronization process on the pseudoscalar DFFs. Our study shows that, even though it is less probable to produce vector mesons in the hadronization process than pseudo scalar mesons of the same charge, the products of their strong decays drastically affect the DFFs for pions because of the large combinatorial factors. Thus, an accurate description of both vector meson production and decays are crucial for theoretical understanding of DFFs. (authors)
Azimuthal correlations of D-mesons in p+p and p+Pb collisions at LHC energies
Younus, M.; Sahu, P.K. [Institute of Physics, Bhubaneswar (India); Tripathy, S.K. [Institute of Physics, Bhubaneswar (India); Sambalpur University, Burla (India); Naik, Z. [Sambalpur University, Burla (India)
2017-05-15
We study the correlations of D mesons produced in p+p and p+Pb collisions. These are found to be sensitive to the effects of the cold nuclear medium and the transverse momentum (p{sub T}) regions we are looking into. In order to put this on a quantitative footing, as a first step we analyse the azimuthal correlations of D meson-charged hadron (Dh), and then predict the same for D meson-anti D meson (D anti D) pairs in p+p and p+Pb collisions with strong coupling at leading order O(α{sub s}{sup 2}) and next-to-leading order O(α{sub s}{sup 3}), which includes space-time evolution (in both systems) as well as cold nuclear matter effects (in p+Pb). This also sets the stage and baseline for the identification and study of medium modification of azimuthal correlations in relativistic collision of heavy nuclei at the Large Hadron Collider. (orig.)
Structure functions of the deuteron with allowance for meson exchange currents within QCD-VMD model
Burov, V.V.
1992-01-01
The deuteron structure functions A(q 2 ), B(q 2 ) and tensor polarization T 20 (q 2 ) are studied within the QCD-VMD model. It is shown that the calculation of the structure functions with allowance for meson exchange currents does not allow us to improve the agreement with experiment at large transfer momenta where probably other degrees of freedom are to be taken into account. 24 refs.; 6 figs
On the mesonic-exchange currents in the photomesic reactions
Lazard, C.; Maric, Z.; Zivanovic, D.
1979-02-01
The γd→π 0 d reaction is analysed in the framework of the relativistic many-body theory with mesonic degrees of freedom explicitly present. It is shown that the mesonic correlations can be grouped into transition operators containing vertices of some elementary reactions between photon, nucleons and pions. The wave function corrections due to meson exchange currents are included in the transition operators and the S-matrix is obtained with the non relativistic deuteron wave function
Parity violating nuclear force by meson mixing
Iqbal, M.J.; Niskanen, J.A.
1990-01-01
We study a mechanism for parity violation in the two nucleon meson-exchange interaction by way of the mixing of mesons of opposite parities. This mixing arises from parity violating W ± and Z exchange between the q bar q pair in the meson. Numerically its effect turns out to be as important as vector meson exchange with a weak meson-nucleon vertex and may partly be used to model this vertex. The calculation is performed using both the standard Born approximation adding the amplitude phases by Watson's theorem and also using the exact correlated two-nucleon wave functions. The effect of correlations and form factors is found to be crucially important at intermediate energies
Greben, J.M.
1982-04-01
Nucleon-trinucleon overlap functions in 4 He have been parametrized as a sum of exponentials, and are fitted to the charge form factor of 4 He. We present results with and without taking account of meson-exchange corrections
A thermodynamical analysis of the π and K meson valence structure functions
Angelini, C.; Pazzi, R.
1982-01-01
The π and K meson valance structure functions are analysed in the framework of a thermodynamical model already applied to the nucleon. We obtain a simple expression which reproduces quite well the data for chi > 0.3. The effective temperatures are found to be of the order of 20 MeV for the pion and 65 MeV for the kaon. (orig.)
Mesonic effects in nuclear physics
Johnson, M.
1978-01-01
The relation between mesons and nucleons and the properties of nuclear matter, as presently understood, is considered in these lectures. Feynman diagrams, meson theoretical nucleon-nucleon interactions, mesonic components in nuclear wave functions, direct observation of mesonic components in NN scattering above the pion production threshold, nuclear matter theory, and pion condensation are treated. 120 references
Hexagonalization of correlation functions
Fleury, Thiago [Instituto de Física Teórica, UNESP - University Estadual Paulista,ICTP South American Institute for Fundamental Research,Rua Dr. Bento Teobaldo Ferraz 271, 01140-070, São Paulo, SP (Brazil); Komatsu, Shota [Perimeter Institute for Theoretical Physics,31 Caroline St N Waterloo, Ontario N2L 2Y5 (Canada)
2017-01-30
We propose a nonperturbative framework to study general correlation functions of single-trace operators in N=4 supersymmetric Yang-Mills theory at large N. The basic strategy is to decompose them into fundamental building blocks called the hexagon form factors, which were introduced earlier to study structure constants using integrability. The decomposition is akin to a triangulation of a Riemann surface, and we thus call it hexagonalization. We propose a set of rules to glue the hexagons together based on symmetry, which naturally incorporate the dependence on the conformal and the R-symmetry cross ratios. Our method is conceptually different from the conventional operator product expansion and automatically takes into account multi-trace operators exchanged in OPE channels. To illustrate the idea in simple set-ups, we compute four-point functions of BPS operators of arbitrary lengths and correlation functions of one Konishi operator and three short BPS operators, all at one loop. In all cases, the results are in perfect agreement with the perturbative data. We also suggest that our method can be a useful tool to study conformal integrals, and show it explicitly for the case of ladder integrals.
D meson-hadron angular correlations in pp and p-Pb collisions with ALICE at the LHC
Colamaria, Fabio
2014-01-01
The comparison of angular correlations between charmed mesons and charged hadrons produced in pp, p-Pb and Pb-Pb collisions can give insight into charm quark energy loss mechanisms in hot nuclear medium formed in heavy-ion collisions and can help to spot possible modifications of charm quark hadronization induced by the presence of the medium. The analysis of pp and p-Pb data and the comparison with predictions from pQCD calculations, besides constituting the necessary baseline for the interpretation of Pb-Pb results, can provide relevant information on charm production and fragmentation processes. We present a study of azimuthal correlations between D$^0$ and D$^{\\ast +}$ mesons and charged hadrons measured by the ALICE experiment in pp collisions at $\\sqrt{s} = 7$ TeV and p-Pb collisions at $\\sqrt{s_{\\rm NN}} = 5.02$ TeV. D mesons were reconstructed from their hadronic decays at central rapidity and in the transverse momentum range $2 < p_{_{\\rm T}} < 16$ GeV/$c$, and they were correlated to charged h...
Fiebig, H. Rudolf
2002-01-01
We study various aspects of extracting spectral information from time correlation functions of lattice QCD by means of Bayesian inference with an entropic prior, the maximum entropy method (MEM). Correlator functions of a heavy-light meson-meson system serve as a repository for lattice data with diverse statistical quality. Attention is given to spectral mass density functions, inferred from the data, and their dependence on the parameters of the MEM. We propose to employ simulated annealing, or cooling, to solve the Bayesian inference problem, and discuss the practical issues of the approach
Mesons above the deconfining transition
De Forcrand, P.; Garcia Perez, M.; Hashimoto, T.
1999-01-01
We analyze temporal and spatial meson correlators in quenched lattice QCD at T > 0. Above T c we find different masses and (spatial) 'screening masses', signals of plasma formation, and indication of persisting 'mesonic' excitations. (author)
Meson-baryon-baryon vertex function and the Ward-Takahashi identity
Wang, S.; Banerjee, M.K.
1996-01-01
Ohta proposed a solution for the well-known difficulty of satisfying the Ward-Takahashi identity for a photo-meson-baryon-baryon amplitude (γMBB) when a dressed meson-baryon-baryon (MBB) vertex function is present. He obtained a form for the γMBB amplitude which contained, in addition to the usual pole terms, longitudinal seagull terms which were determined entirely by the MBB vertex function. He arrived at his result by using a Lagrangian which yields the MBB vertex function at tree level. We show that such a Lagrangian can be neither Hermitian nor charge conjugation invariant. We have been able to reproduce Ohta close-quote s result for the γMBB amplitude using the Ward-Takahashi identity and no other assumption, dynamical or otherwise, and the most general form for the MBB and γMBB vertices. However, contrary to Ohta close-quote s finding, we find that the seagull terms are not robust. The seagull terms extracted from the γMBB vertex occur unchanged in tree graphs, such as in an exchange current amplitude. But the seagull terms which appear in a loop graph, as in the calculation of an electromagnetic form factor, are, in general, different. The whole procedure says nothing about the transverse part of the (γMBB) vertex and its contributions to the amplitudes in question. copyright 1996 The American Physical Society
Kneesch, Torben
2010-12-15
We have calculated the single-inclusive production cross section of massive quarks in electron-positron-annihilation with next-to-leading order QCD corrections. With these results we have extracted fragmentation functions for the fragmentation from partons into D{sup 0}, D{sup +} and D{sup *} mesons, where we have used experimental data from the B factories Belle and CLEO and from the ALEPH and OPAL experiments at the LEP collider. In our analysis we have included the masses of c and b quarks and of the D mesons and tested the evolution of fragmentation functions with a global fit spanning the B factories' center-of-mass energy of {radical}(s)=10.5 GeV to LEP's run at the Z boson resonance at M{sub Z}. We have applied this fragmentation functions in deep inelastic scattering for comparisons with HERA data using parton cross sections from the literature available in program form. We have then modified this cross section to calculate predictions for deep inelastic two-photon-scattering. By applying the Weizsaecker-Williams spectrum on the real photon we have calculated predictions for LEP1, LEP2 and the future ILC experiments. For ILC we have also included a beamstrahlung spectrum. Finally we have calculated production cross sections for the planned e{gamma} mode of the ILC with the help of a Compton spectrum. (orig.)
Bayukov, Yu.D.; Vlasov, A.V.; Gavrilov, V.B.
1981-01-01
Hardonic correlations were investigated in reactions with the proton backward production induced by 6.0-GeV/c π - mesons on nuclei Be, C, Al, Cu, Cd, Pb, U. The studied correlations indicate an essential role of multiple interactions of the incident particle in production of cumulative protons [ru
The light scalar mesons as tetraquarks
Gernot Eichmann
2016-02-01
Full Text Available We present a numerical solution of the four-quark Bethe–Salpeter equation for ground-state scalar tetraquarks with JPC=0++. We find that the four-body equation dynamically generates pseudoscalar-meson poles in the Bethe–Salpeter amplitude. The resulting tetraquarks are genuine four-quark states that are dominated by pseudoscalar meson–meson correlations. Diquark–antidiquark contributions are subleading because of their larger mass scale. In the light quark sector, the sensitivity of the tetraquark wave function to the pion poles leads to an isoscalar tetraquark mass Mσ∼350 MeV which is comparable to that of the σ/f0(500. The masses of its multiplet partners κ and a0/f0 follow a similar pattern. This provides support for a tetraquark interpretation of the light scalar meson nonet in terms of ‘meson molecules’.
1996-09-01
We present evidence for charge correlations of B mesons with charged particles produced in p anti p Collisions at 1.8 TeV. Such correlations are expected to arise from pious produced in the fragmentation chain and from B ** decays. We measure the efficiency and purity of this flavor tagging method for both charged and neutral B mesons. We apply these correlations to B mesons reconstructed in 110 pb -1 of data collected with the CDF detector at the Fermilab Tevatron Collider. B mesons are either partially reconstructed, using the semileptonic decays B 0 → l + D (*)- X and B + → l + anti DX, or fully reconstructed, using the decay modes B 0 → J/ΨK *0 and B + → J/ΨK + . Application of this new flavor tagging method to neutral B mesons yields a measurement of the frequency of the oscillation B 0 → anti B 0 . We obtain Δm d = 0.446 ± 0.057 +0.034 -0.031
Correlation Functions and Power Spectra
Larsen, Jan
2006-01-01
The present lecture note is a supplement to the textbook Digital Signal Processing by J. Proakis and D.G. Manolakis used in the IMM/DTU course 02451 Digital Signal Processing and provides an extended discussion of correlation functions and power spectra. The definitions of correlation functions...... and spectra for discrete-time and continuous-time (analog) signals are pretty similar. Consequently, we confine the discussion mainly to real discrete-time signals. The Appendix contains detailed definitions and properties of correlation functions and spectra for analog as well as discrete-time signals....... It is possible to define correlation functions and associated spectra for aperiodic, periodic and random signals although the interpretation is different. Moreover, we will discuss correlation functions when mixing these basic signal types. In addition, the note include several examples for the purpose...
Nuclear correlations and structure functions
Hu Guoju; Irvine, J.M.
1989-01-01
It is argued that the search for a mass number dependence of the nuclear structure function per nucleon is profitably directed to the region of Bjorken scaling variable x > 1. We show that in the convolution model of the nuclear structure function the nuclear momentum distribution and energy spectrum generated by cluster expansion techniques, here realised in the correlated basis function method, invoking tensor correlations and short-range density-dependent repulsions adequately describes the structure function for 12 C in the region x > 1. The results of structure functions for a number of light-, medium- and heavy-mass nuclei are presented. (author)
Oda, Ryuichi; Ishida, Shin; Wada, Hiroaki; Yamada, Kenji; Sekiguchi, Motoo
1999-01-01
We examine mass spectra and wave functions of the nn-bar, cc-bar and bb-bar meson systems within the framework of the covariant oscillator quark model with the boosted LS-coupling scheme. We solve nonperturbatively an eigenvalue problem for the squared-mass operator, which incorporates the four-dimensional color-Coulomb-type interaction, by taking a set of covariant oscillator wave functions as an expansion basis. We obtain mass spectra of these meson systems, which reproduce quite well their experimental behavior. The resultant manifestly covariant wave functions, which are applicable to analyses of various reaction phenomena, are given. Our results seem to suggest that the present model may be considered effectively as a covariant version of the nonrelativistic linear-plus-Coulomb potential quark model. (author)
Bhatnagar, S.; Li, Shiyuan; Mahecha, J.
2011-01-01
We have employed the framework of Bethe–Salpeter equation under covariant instantaneous ansatz to calculate leptonic decay constants of unequal mass pseudoscalar mesons like π ± , K, D, D S and B, and radiative decay constants of neutral pseudoscalar mesons like π 0 and η c into two photons. In the Dirac structure of hadronic Bethe–Salpeter wave function, the covariants are incorporated from their complete set in accordance with a recently proposed power counting rule. The contribution of both leading order and next-to-leading order Dirac covariants to decay constants are studied. The results are found to improve and hence validating the power counting rule which provides a practical means of incorporating Dirac covariants in the Bethe–Salpeter wave function for a hadron. (author)
Savron, V.I.; Skachkov, N.B.; Tyumenkov, G.Yu.
1982-01-01
A covariant three dimensional equation is derived for a wave function of a pseudoscalar particle, compoused of two equal mass quarks (quark and antiquark) with spins 1/2. This equation describes a relative motion of two quarks in π meson. An asymptotics of the solution of this equation is found in the momentum representation in the case of quarks interaction chosen in a form of a one gluon exchange amplitude [ru
Semay, Claude; Buisseret, Fabien; Silvestre-Brac, Bernard
2009-01-01
A hybrid meson is a quark-antiquark pair in which, contrary to ordinary mesons, the gluon field is in an excited state. In the framework of constituent models, the interaction potential is assumed to be the energy of an excited string. An approximate, but accurate, analytical solution of the Schroedinger equation with such a potential is presented. When applied to hybrid charmonia and bottomonia, towers of states are predicted in which the masses are a linear function of a harmonic oscillator band number for the quark-antiquark pair. Such a formula could be a reliable guide for the experimental detection of heavy hybrid mesons.
Penev, V.N.; Shklovskaya, A.I.
1980-01-01
The results of additional studies on the production of secondary particles having large transverse momentum (main secondary particles) in π - -p-interactions at 40 GeV/c are presented. Correlations between secondary particles are investigated in two channels: (1) π - p→πsub(psub(T)>0.8 +- )+...; (2) π - p→πsub(psub(T)>0.8 +- )+πsub(psub(T)>0.8 +- )+..., where πsub(psub(T)>0.8 +- ) are π-mesons having transverse momentum larger than 0.8 GeV/c. For the first type events (1) the rapidity distribution and the average rapidity of the particles accompanying the main particle are obtained. The rapidity distribution depends on the transverse momentum of the accompanying particles. The asimuthal asymmetry increases with increasing of this momentum. The average rapidity is independent of the asimuthal angle, but very strongly depends on the rapidity of the main particle - it decreases with the increase of rapidity. It is also shown, that the average difference between the averaae rapidities of the main particle and the accompanying particles are influenced by the combination of their charges. The average difference is minimum for identical charges and very strongly increases for the opposite charges. The obtained rapidity distribution is studied for events, in which two π +- -mesons of large momentum psub(T)>0.8 GeV/c are produced (type 2). The rapidity distribution of each of the π +- -mesons is broader than the center of mass rapidity distribution. This fact could be an indication of a presence of correlations in the production of two π +- -mesons. The distribution of the absolute difference between the rapidity of the π +- -mesons is given as well and its peak is at zero difference. These results indicate, that the possibility is highest for production of two π +- -mesons of almost equal transverse momentum. The obtained charge particle multiplicity distribution shows that the average multiplicity is lower than the corresponding values for all inelastic
Bhatnagar, Shashank [Department of Physics, Addis Ababa University, PO Box 101739, Addis Ababa (Ethiopia); Li Shiyuan [Department of Physics, Shandong University, Jinan, 250100 (China)
2006-07-15
We employ the framework of the Bethe-Salpeter equation under a covariant instantaneous ansatz to study the leptonic decays of vector mesons. The structure of the hadron-quark vertex function {gamma} is generalized to include various Dirac covariants (other than i{gamma} . {epsilon}) from their complete set. They are incorporated in accordance with a naive power counting rule order-by-order in powers of the inverse of the meson mass. The decay constants for {rho}, {omega} and {phi} mesons are calculated with the incorporation of leading-order covariants.
Bhatnagar, Shashank; Li Shiyuan
2006-01-01
We employ the framework of the Bethe-Salpeter equation under a covariant instantaneous ansatz to study the leptonic decays of vector mesons. The structure of the hadron-quark vertex function Γ is generalized to include various Dirac covariants (other than iγ . ε) from their complete set. They are incorporated in accordance with a naive power counting rule order-by-order in powers of the inverse of the meson mass. The decay constants for ρ, ω and φ mesons are calculated with the incorporation of leading-order covariants
Oscillations of the static meson fields at finite baryon density
Florkowski, W.; Friman, B.; Technische Hochschule Darmstadt
1996-04-01
The spatial dependence of static meson correlation functions at finite baryon density is studied in the Nambu-Jona-Lasinio model. In contrast to the finite temperature case, we find that the correlation functions at finite density are not screened but exhibit long-range oscillations. The observed phenomenon is analogous to the Friedel oscillations in a degenerate electron gas. (orig.)
Meson-meson scattering in lattice QED2+1
Fiebig, H.R.; Woloshyn, R.M.
1993-01-01
Scattering phase shifts of a meson-meson system in staggered 3-dimensional lattice QED are computed. The main task of the simulation is to obtain a discrete set of two-body energy levels. These are extracted from a 4-point time correlation matrix and then used to obtain scattering phase shifts. The results for the l = 0 and l = 2 partial waves are consistent with short-range repulsion and intermediate-range attraction of the residual meson-meson interaction. (orig.)
The ATLAS collaboration
2017-01-01
The production of $D^{0}(\\overline{D^0})$ and $D^{*\\pm}$ mesons has been measured with the ATLAS detector in $p$+Pb collisions at $\\sqrt{s_{_\\mathrm{NN}}}=8.16~\\mathrm{TeV}$ with an integrated luminosity of $76.3\\mu b^{-1}$ taken in 2016. The $D$ meson production asymmetry between forward ($0 < y^* < 0.5$) and backward ($-0.5 < y^* < 0$) center-of-mass rapidities is studied, and no significant asymmetry is observed. Azimuthal correlations between inclusive $D^{*\\pm}$ and charged particles are also presented in intervals of event-wise charged-particle multiplicity. The second-order harmonic coefficients for inclusive $D^{*\\pm}$ and charged particles azimuthal correlation have been extracted using template fits.
Soleymaninia, Maryam; Khanpour, Hamzeh; Nejad, S. Mohammad Moosavi
2018-04-01
We present, for the first time, a set of next-to-next-to-leading order (NNLO) fragmentation functions (FFs) describing the production of charmed-meson D* from partons. Exploiting the universality and scaling violations of FFs, we extract the NLO and NNLO FFs through a global fit to all relevant data sets from single-inclusive e+e- annihilation. The uncertainties for the resulting FFs as well as the corresponding observables are estimated using the Hessian approach. We evaluate the quality of the SKM18 FFs determined in this analysis by comparing with the recent results in literature and show how they describe the available data for single-inclusive D*±-meson production in electron-positron annihilation. As a practical application, we apply the extracted FFs to make our theoretical predictions for the scaled-energy distributions of D*±-mesons inclusively produced in top quark decays. We explore the implications of SKM18 for LHC phenomenology and show that our findings of this study can be introduced as a channel to indirect search for top-quark properties.
Huang, Zhijie; Shi, Yu.
2012-01-01
We present a general model-independent formalism of measuring CP and CPT violating parameters through time-ordered integrated rates of correlated decays of C=±1 entangled states of neutral pseudoscalar mesons. We give the general formulae of CP and CPT violating parameters in terms of four measurable asymmetries defined for the time-ordered integrated rates, applicable to all kinds of decay product. Two special cases which are often realized in experiments are discussed specifically. (orig.)
Correlation functions of warped CFT
Song, Wei; Xu, Jianfei
2018-04-01
Warped conformal field theory (WCFT) is a two dimensional quantum field theory whose local symmetry algebra consists of a Virasoro algebra and a U(1) Kac-Moody algebra. In this paper, we study correlation functions for primary operators in WCFT. Similar to conformal symmetry, warped conformal symmetry is very constraining. The form of the two and three point functions are determined by the global warped conformal symmetry while the four point functions can be determined up to an arbitrary function of the cross ratio. The warped conformal bootstrap equation are constructed by formulating the notion of crossing symmetry. In the large central charge limit, four point functions can be decomposed into global warped conformal blocks, which can be solved exactly. Furthermore, we revisit the scattering problem in warped AdS spacetime (WAdS), and give a prescription on how to match the bulk result to a WCFT retarded Green's function. Our result is consistent with the conjectured holographic dualities between WCFT and WAdS.
D meson production and long-range azimuthal correlation in 8.16 TeV p+Pb collisions with ATLAS
Hu, Qipeng; The ATLAS collaboration
2017-01-01
Measurements of production of prompt charm mesons (D0 and D*) and azimuthal correlations between inclusive D* and charged particles are presented in p+Pb collisions data at 8.16 TeV collected in 2016 by ATLAS. The prompt charm meson production is measured in minimum bias p+Pb data, reconstructed via two decay channels: D0->K+pi and D*->D0+pi->K+pi+pi. The production asymmetry between forward and backward center-of-mass rapidities for the charm mesons is studied for the range of |y*| < 0.5, and no significant asymmetry is observed. In the D*-hadron correlations, the pT of identified D* is more closely related to the pt of primordial heavy quarks, relative to the measurement of their decay muons. A finite elliptic harmonic coefficient for inclusive D* and charge particles have been extracted with a significance of one to two standard deviations, depending on multiplicity, broadly consistent with what have been observed for light hadrons and muons from heavy quark decaying.
Estimation of Correlation Functions by Random Decrement
Asmussen, J. C.; Brincker, Rune
This paper illustrates how correlation functions can be estimated by the random decrement technique. Several different formulations of the random decrement technique, estimating the correlation functions are considered. The speed and accuracy of the different formulations of the random decrement...... and the length of the correlation functions. The accuracy of the estimates with respect to the theoretical correlation functions and the modal parameters are both investigated. The modal parameters are extracted from the correlation functions using the polyreference time domain technique....
Structure function of carbon nucleus in cumulative π-meson photoproduction processes
Egiyan, K.Sh.; Ohandjanyan, M.S.
1992-01-01
The results of data analysis (10,11) on π meson photoproduction on nucleus 1 2C at E γ m ax = 4,5 GeV from the point of obtaining information about factorization of invariant cross section f π (α,P l 2 ) are presented. It is shown that in the representation f π (α,P l 2 ) ∼ f 1π (α )
Maksimovic, Peter [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
1998-02-01
We present a study of time dependent B^{0}-$\\bar{B}$^{0} mixing in p$\\bar{p}$ collisions at 1.8 TeV using 110 pb^{-1} collected with the CDF detector at the Fermilab Tevatron Collider. B mesons are partially reconstructed using the semileptonic decays B^{0}→l^{+}D^{*-}X and B^{+}→l^{+}$\\bar{D}$^{0}X (and their charge conjugates). B meson-charged pion correlations are used in order to determine the flavor of the B meson at t=0. Such correlations are expected to arise from pions produced in the fragmentation chain and also from B** decays. We measure the efficiency and purity of this flavor tagging method for both charged and neutral B mesons.
Functional Multiple-Set Canonical Correlation Analysis
Hwang, Heungsun; Jung, Kwanghee; Takane, Yoshio; Woodward, Todd S.
2012-01-01
We propose functional multiple-set canonical correlation analysis for exploring associations among multiple sets of functions. The proposed method includes functional canonical correlation analysis as a special case when only two sets of functions are considered. As in classical multiple-set canonical correlation analysis, computationally, the…
Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaraz, J. R. M.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Balasubramanian, S.; Baldisseri, A.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Beltran, L. G. E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Bjelogrlic, S.; Blair, J. T.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Bonora, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Iga Buitron, S. A.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caffarri, D.; Cai, X.; Caines, H.; Diaz, L. Calero; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A R; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Cho, Sukhee; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crkovská, J.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; Dasgupta, S. S.; De Caro, A.; De Cataldo, G.; De Conti, C.; De Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Souza, R. Derradi; Deisting, A.; Deloff, A.; Dénes, E.; Deplano, C.; Dhankher, P.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Di Ruzza, B.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, O.; Dobrin, A.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erdemir, I.; Erhardt, F.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A S; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; De Francisco, A.; Frankenfeld, U.; Fronze, G. G.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gajdosova, K.; Gallio, M.; Galvan, C. D.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Gauger, E. F.; Germain, M.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; Gonzalez, A. S.; Gonzalez, V; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Grachov, O. A.; Graczykowski, L. K.; Graham, K. L.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gronefeld, J. M.; Grosse-Oetringhaus, J. F.; Grosso, R.; Gruber, L.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hamon, J. C.; Harris, J. W.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Hellbär, E.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Hess, B. A.; Hetland, K. F.; Hillemanns, H.; Hippolyte, B.; Horak, D.; Hosokawa, R.; Hristov, P.; Hughes, C.W.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Inaba, M.; Incani, E.; Ippolitov, M.; Irfan, M.; Isakov, V.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacak, B.; Jacazio, N.; Jacobs, P. M.; Jadhav, M. B.; Jadlovska, S.; Jadlovsky, J.; Jahnke, C.; Jakubowska, M. J.; Janik, M. A.; Jayarathna, P. H S Y; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karayan, L.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L.D.; Keil, M.; Khan, M. Mohisin; Khan, P.M.; Khan, Shfaqat A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, D. W.; Kim, D. J.; Kim, D.-S.; Kim, H.; Kim, J. S.; Kim, J.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C; Klein, J.; Klein-Bösing, C.; Klewin, S.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kopcik, M.; Kour, M.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.L.; Koyithatta Meethaleveedu, G.; Králik, I.; Kravčáková, A.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kuhn, C.; Kuijer, P. G.; Kumar, A.; Kumar, J.; Kumar, L.; Kumar, S.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Ladron de Guevara, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lapidus, K.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lea, R.; Leardini, L.; Lee, S.; Lehas, F.; Strunz-Lehner, Christine; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; León Vargas, H.; Leoncino, M.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Lopez, X.; López Torres, E.; Lowe, A.; Luettig, P.; Lunardon, M.; Luparello, G.; Lupi, M.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal’Kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, Alicia; Markert, C.; Marquard, M.; Martin, N. A.; Martinengo, P.; Martínez, Isabel M.; Martínez García, G.; Martinez Pedreira, M.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Mastroserio, A.; Matyja, A.; mayer, C.; Mazer, J.; Mazzoni, M. A.; McDonald, D.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Mhlanga, S.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montaño Zetina, L.; Montes, E.; Moreira De Godoy, D. A.; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Münning, K.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Naik, B.; Nair, Rajiv; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Natal Da Luz, H.; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Negrao De Oliveira, R. A.; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Ohlson, A.; Okatan, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Oravec, M.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pagano, D.; Pagano, P.; Paić, G.; Pal, S. K.; Palni, P.; Pan, J.; Pandey, A. K.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, J.; Park, J.-W.; Parmar, S.; Passfeld, A.; Paticchio, V.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.; Peng, X.; Pereira Da Costa, H.; Peresunko, D.; Perez Lezama, E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L M; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Poppenborg, H.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Raniwala, R.; Raniwala, S.; Räsänen, S.; Rascanu, B. T.; Rathee, D.; Read, K. F.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rocco, E.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. 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2017-01-01
The azimuthal correlations of D mesons with charged particles were measured with the ALICE apparatus in pp collisions at s=7TeV and p–Pb collisions at sNN=5.02TeV at the Large Hadron Collider. D 0, D +, and D ∗ + mesons and their charge conjugates with transverse momentum 3
Batskovich, S.; Grishin, V.G.; Jenik, L.; Kanarek, T.
1979-01-01
Values of correlation functions are obtained for two-and three particle inclusive processes in π - p, π - n and π -12 C collisions at p=40 GeV/c. The results are obtained while analyzing 9940 π - p, 3590 π - n and approximately 11000 π 12 C inelastic interactions. Correlation values are obtained for various combinations of charged particles. Correlation value at different values of Q is also given for π -12 C events, Q being equal to the difference of positive and negative pions in the given event. Azimuthal correlations are studied for π + π + , π + π - and π - π - pairs, produced in π - p, π - n and π -12 C interactions. The correlations were studied in various ranges of particle rates and at various values of Q. Experimental data on azimuthal correlations are tabulated. The results of correlation measurements over rates and azimuthal angle in π -12 C collisions confirm predictions of the additive quark model and contradict the eikonal model. Measurements of correlation functions is emphasized to be the most sensitive way providing a possibility to find out the source of correlation on nuclei
Takasugi, E.; Tata, X.
1982-01-01
The recombination model associated with modified Kuti-Weisskopf multiquark structure functions is used to analyze particle production by hadronic collisions. The justification of the use of the impulse approximation in these processes and the universal nature of the recombination process are discussed. Single-meson inclusive production in the fragmentation domains of the proton, the pion, and the kaon is used as an input to determine the primitive structure functions. Our parameter-free predictions for low-p/sub T/ multimeson and associated meson-baryon inclusive production are found to be in good agreement with a large amount of recently obtained correlation data. It is pointed out, however, that reactions involving multivalence recombination fall outside the scope of present considerations
Significance and properties of internucleon correlation functions
Suzuki, Y.; Horiuchi, W.
2008-01-01
We show that a nuclear Hamiltonian and a set of internucleon correlation functions is in a one-to-one correspondence. The correlation functions for $s$-shell nuclei interacting via the two-nucleon interaction of AV8$^\\prime$ type are calculated to exhibit the importance of tensor correlations as well as short-range central correlation. The asymptotic behavior of the correlation functions is also discussed.
D meson production and long-range azimuthal correlation in 8.16 TeV p+Pb collisions with ATLAS
Hu, Qipeng; The ATLAS collaboration
2018-01-01
Measurements of prompt charm mesons ($D^0$ and $D^*$) productions and azimuthal correlations between inclusive $D^*$ and charged particles are presented in p+Pb collisions data at 8.16 TeV collected in 2016 by ATLAS. No significant production asymmetry between forward and backward and asymmetry is observed. A finite $2\\cos(2\\Delta\\phi)$ modulation for inclusive $D^*$ is observed with a $1\\sim2\\sigma$ significance, depending on multiplicity, broadly consistent with what have been observed for light hadrons and HF muons.
Using correlation functions as free decays
Brincker, Rune; Amador, Sandro; Juul, Martin
It is a general assumption in OMA that correlation functions are free decays. In multiple input OMA this assumption also implies that any column in the correlation function matrix is to be considered as multiple output free decays. This assumption is discussed in this paper together with issues...... concerning estimation and application of correlations functions in OMA....
Dicello, J.F.; Zaider, M.; Bradbury, J.N.
1979-01-01
Technological improvements in accelerator design in the 1960's resulted in the capability to develop medium-energy proton accelerators with beam intensities of almost 1 mA. These beams are able to produce fluxes of secondary particles, including pions, muons, neutrinos, and neutrons, which are as much as 10,000 times as intense as those previously available. Those machines built for optimum meson production are commonly called meson factories. The characteristics of these facilities are reviewed, and the present programs in applied research, and some potential areas of future work are discussed
Chanfray, G.; Aouissat, Z.; Schuck, P.; Norenberg, W.
1990-01-01
The most important part of the intermediate range nucleon-nucleon attraction is attributed to the exchange of non interacting as well as interaction two pions in the I = J = O channel. The corresponding 2π exchange potential, or part of it, is often simulated by a sigma-meson exchange with mass of about 600 MeV, which is then used as a basic input to nuclear matter calculation. This may give in particular a justification to the popular σ-ψ model. However a number of question remains concerning the microscopic nature of such an effective sigma meson. The point the authors want to emphasize in this paper concerns the possible modification of the sigma in the medium since they think that it is made out of pions whose propagations are strongly altered by the medium. However also the ρ-meson may undergo similar in medium corrections which possibly are related to recent experimental findings. The authors discuss, with a very simple model, the problem of pion propagation and pion-pion interaction in the medium and the occurrence of highly collective pion-delta modes (pionic branch, pisobar, quasi pion) in agreement with experimental data. They also should have some very important consequences on the dynamics of relativistic heavy collision. The authors address the very important question of the nuclear matter equation of state where collective pionic effects are included to reconstruct an effective sigma exchange whose mass and coupling constant are density dependent
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2017-01-01
The azimuthal correlations of D mesons with charged particles were measured with the ALICE apparatus in pp collisions at [Formula: see text] and p-Pb collisions at [Formula: see text] at the Large Hadron Collider. [Formula: see text], [Formula: see text], and [Formula: see text] mesons and their charge conjugates with transverse momentum [Formula: see text] and rapidity in the nucleon-nucleon centre-of-mass system [Formula: see text] (pp collisions) and [Formula: see text] (p-Pb collisions) were correlated to charged particles with [Formula: see text]. The yield of charged particles in the correlation peak induced by the jet containing the D meson and the peak width are compatible within uncertainties in the two collision systems. The data are described within uncertainties by Monte-Carlo simulations based on PYTHIA, POWHEG, and EPOS 3 event generators.
Oscillations of the static meson fields at finite baryon density
Florkowski, W.; Friman, B.; Technische Hochschule Darmstadt
1996-04-01
The spatial dependence of static meson correlation functions at finite baryon density is studied in the Nambu-Jona-Lasinio model. In contrast to the finite temperature case, we find that the correlation functions at finite density are not screened but exhibit long-range oscillations. The observed phenomenon is analogous to the Friedel oscillations in a degenerate electron gas. (author). 19 refs, 6 figs
Han Xiaofang; Wang Lei; Yang Jinmin
2008-01-01
In the littlest Higgs model with T-parity new flavor-changing interactions between mirror fermions and the standard model (SM) fermions can induce various flavor-changing neutral-current decays for B-mesons, the Z-boson, and the Higgs boson. Since all these decays induced in the littlest Higgs with T-parity model are correlated, in this work we perform a collective study for these decays, namely, the Z-boson decay Z→bs, the Higgs-boson decay h→bs, and the B-meson decays B→X s γ, B s →μ + μ - , and B→X s μ + μ - . We find that under the current experimental constraints from the B-decays, the branching ratios of both Z→bs and h→bs can still deviate from the SM predictions significantly. In the parameter space allowed by the B-decays, the branching ratio of Z→bs can be enhanced up to 10 -7 (about one order above the SM prediction) while h→bs can be much suppressed relative to the SM prediction (about one order below the SM prediction).
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Luettig, Philipp Johannes; Lunardon, Marcello; Luparello, Grazia; Lupi, Matteo; Lutz, Tyler Harrison; Maevskaya, Alla; Mager, Magnus; Mahajan, Sanjay; Mahmood, Sohail Musa; Maire, Antonin; Majka, Richard Daniel; Malaev, Mikhail; Maldonado Cervantes, Ivonne Alicia; Malinina, Liudmila; Mal'Kevich, Dmitry; Malzacher, Peter; Mamonov, Alexander; Manko, Vladislav; Manso, Franck; Manzari, Vito; Mao, Yaxian; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Margutti, Jacopo; Marin, Ana Maria; Markert, Christina; Marquard, Marco; Martin, Nicole Alice; Martinengo, Paolo; Martinez Hernandez, Mario Ivan; Martinez-Garcia, Gines; Martinez Pedreira, Miguel; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Mastroserio, Annalisa; Matyja, Adam Tomasz; Mayer, Christoph; Mazer, Joel Anthony; Mazzoni, Alessandra Maria; Mcdonald, Daniel; Meddi, Franco; Melikyan, Yuri; Menchaca-Rocha, Arturo Alejandro; Meninno, Elisa; Mercado-Perez, Jorge; Meres, Michal; Mhlanga, Sibaliso; Miake, Yasuo; Mieskolainen, Matti Mikael; Mikhaylov, Konstantin; Milano, Leonardo; Milosevic, Jovan; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz Czeslaw; Mitra, Jubin; Mitu, Ciprian Mihai; Mohammadi, Naghmeh; Mohanty, Bedangadas; Molnar, Levente; Montano Zetina, Luis Manuel; Montes Prado, Esther; Moreira De Godoy, Denise Aparecida; Perez Moreno, Luis Alberto; Moretto, Sandra; Morreale, Astrid; Morsch, Andreas; Muccifora, Valeria; Mudnic, Eugen; Muhlheim, Daniel Michael; Muhuri, Sanjib; Mukherjee, Maitreyee; Mulligan, James Declan; Gameiro Munhoz, Marcelo; Munning, Konstantin; Munzer, Robert Helmut; Murakami, Hikari; Murray, Sean; Musa, Luciano; Musinsky, Jan; Naik, Bharati; Nair, Rahul; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Naru, Muhammad Umair; Ferreira Natal Da Luz, Pedro Hugo; Nattrass, Christine; Rosado Navarro, Sebastian; Nayak, Kishora; Nayak, Ranjit; Nayak, Tapan Kumar; Nazarenko, Sergey; Nedosekin, Alexander; Negrao De Oliveira, Renato Aparecido; Nellen, Lukas; Ng, Fabian; Nicassio, Maria; Niculescu, Mihai; Niedziela, Jeremi; Nielsen, Borge Svane; Nikolaev, Sergey; Nikulin, Sergey; Nikulin, Vladimir; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Cabanillas Noris, Juan Carlos; Norman, Jaime; Nyanin, Alexander; Nystrand, Joakim Ingemar; Oeschler, Helmut Oskar; Oh, Saehanseul; Oh, Sun Kun; Ohlson, Alice Elisabeth; Okatan, Ali; Okubo, Tsubasa; Oleniacz, Janusz; Oliveira Da Silva, Antonio Carlos; Oliver, Michael Henry; Onderwaater, Jacobus; Oppedisano, Chiara; Orava, Risto; Oravec, Matej; Ortiz Velasquez, Antonio; Oskarsson, Anders Nils Erik; Otwinowski, Jacek Tomasz; Oyama, Ken; Ozdemir, Mahmut; Pachmayer, Yvonne Chiara; Pagano, Davide; Pagano, Paola; Paic, Guy; Pal, Susanta Kumar; Palni, Prabhakar; Pan, Jinjin; Pandey, Ashutosh Kumar; Papikyan, Vardanush; Pappalardo, Giuseppe; Pareek, Pooja; Park, Woojin; Parmar, Sonia; Passfeld, Annika; Paticchio, Vincenzo; Patra, Rajendra Nath; Paul, Biswarup; Pei, Hua; Peitzmann, Thomas; Peng, Xinye; Pereira Da Costa, Hugo Denis Antonio; Peresunko, Dmitry Yurevich; Perez Lezama, Edgar; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petrov, Viacheslav; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Pikna, Miroslav; Pillot, Philippe; Ozelin De Lima Pimentel, Lais; Pinazza, Ombretta; Pinsky, Lawrence; Piyarathna, Danthasinghe; Ploskon, Mateusz Andrzej; Planinic, Mirko; Pluta, Jan Marian; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Polishchuk, Boris; Poljak, Nikola; Poonsawat, Wanchaloem; Pop, Amalia; Poppenborg, Hendrik; Porteboeuf, Sarah Julie; Porter, R Jefferson; Pospisil, Jan; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puccio, Maximiliano; Puddu, Giovanna; Pujahari, Prabhat Ranjan; Punin, Valery; Putschke, Jorn Henning; Qvigstad, Henrik; Rachevski, Alexandre; Raha, Sibaji; Rajput, Sonia; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Rami, Fouad; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Read, Kenneth Francis; Redlich, Krzysztof; Reed, Rosi Jan; Rehman, Attiq Ur; Reichelt, Patrick Simon; Reidt, Felix; Ren, Xiaowen; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; Reygers, Klaus Johannes; Riabov, Viktor; Ricci, Renato Angelo; Richert, Tuva Ora Herenui; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Ristea, Catalin-Lucian; Rocco, Elena; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roeed, Ketil; Rogochaya, Elena; Rohr, David Michael; Roehrich, Dieter; Ronchetti, Federico; Ronflette, Lucile; Rosnet, Philippe; Rossi, Andrea; Roukoutakis, Filimon; Roy, Ankhi; Roy, Christelle Sophie; Roy, Pradip Kumar; Rubio Montero, Antonio Juan; Rui, Rinaldo; Russo, Riccardo; Ryabinkin, Evgeny; Ryabov, Yury; Rybicki, Andrzej; Saarinen, Sampo; Sadhu, Samrangy; Sadovskiy, Sergey; Safarik, Karel; Sahlmuller, Baldo; Sahoo, Pragati; Sahoo, Raghunath; Sahoo, Sarita; Sahu, Pradip Kumar; Saini, Jogender; Sakai, Shingo; Saleh, Mohammad Ahmad; Salzwedel, Jai Samuel Nielsen; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Sarkar, Debojit; Sarkar, Nachiketa; Sarma, Pranjal; Scapparone, Eugenio; Scarlassara, Fernando; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schmidt, Martin; Schuchmann, Simone; Schukraft, Jurgen; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Rebecca Michelle; Sefcik, Michal; Seger, Janet Elizabeth; Sekiguchi, Yuko; Sekihata, Daiki; Selyuzhenkov, Ilya; Senosi, Kgotlaesele; Senyukov, Serhiy; Serradilla Rodriguez, Eulogio; Sevcenco, Adrian; Shabanov, Arseniy; Shabetai, Alexandre; Shadura, Oksana; Shahoyan, Ruben; Shangaraev, Artem; Sharma, Ankita; Sharma, Mona; Sharma, Monika; Sharma, Natasha; Sheikh, Ashik Ikbal; Shigaki, Kenta; Shou, Qiye; Shtejer Diaz, Katherin; Sibiryak, Yury; Siddhanta, Sabyasachi; Sielewicz, Krzysztof Marek; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Silvestre, Catherine Micaela; Simatovic, Goran; Simonetti, Giuseppe; Singaraju, Rama Narayana; Singh, Ranbir; Singhal, Vikas; Sarkar - Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Slupecki, Maciej; Smirnov, Nikolai; Snellings, Raimond; Snellman, Tomas Wilhelm; Song, Jihye; Song, Myunggeun; Song, Zixuan; Soramel, Francesca; Sorensen, Soren Pontoppidan; Sozzi, Federica; Spiriti, Eleuterio; Sputowska, Iwona Anna; Spyropoulou-Stassinaki, Martha; Stachel, Johanna; Stan, Ionel; Stankus, Paul; Stenlund, Evert Anders; Steyn, Gideon Francois; Stiller, Johannes Hendrik; Stocco, Diego; Strmen, Peter; Alarcon Do Passo Suaide, Alexandre; Sugitate, Toru; Suire, Christophe Pierre; Suleymanov, Mais Kazim Oglu; Suljic, Miljenko; Sultanov, Rishat; Sumbera, Michal; Sumowidagdo, Suharyo; Szabo, Alexander; Szarka, Imrich; Szczepankiewicz, Adam; Szymanski, Maciej Pawel; Tabassam, Uzma; Takahashi, Jun; Tambave, Ganesh Jagannath; Tanaka, Naoto; Tarhini, Mohamad; Tariq, Mohammad; Tarzila, Madalina-Gabriela; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terasaki, Kohei; Terrevoli, Cristina; Teyssier, Boris; Thaeder, Jochen Mathias; Thakur, Dhananjaya; Thomas, Deepa; Tieulent, Raphael Noel; Tikhonov, Anatoly; Timmins, Anthony Robert; Toia, Alberica; Trogolo, Stefano; Trombetta, Giuseppe; Trubnikov, Victor; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vala, Martin; Valencia Palomo, Lizardo; Vallero, Sara; Van Der Maarel, Jasper; Van Hoorne, Jacobus Willem; Van Leeuwen, Marco; Vanat, Tomas; Vande Vyvre, Pierre; Varga, Dezso; Diozcora Vargas Trevino, Aurora; Vargyas, Marton; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vauthier, Astrid; Vazquez Doce, Oton; Vechernin, Vladimir; Veen, Annelies Marianne; Veldhoen, Misha; Velure, Arild; Vercellin, Ermanno; Vergara Limon, Sergio; Vernet, Renaud; Verweij, Marta; Vickovic, Linda; Viinikainen, Jussi Samuli; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Villatoro Tello, Abraham; Vinogradov, Alexander; Vinogradov, Leonid; Virgili, Tiziano; Vislavicius, Vytautas; Viyogi, Yogendra; Vodopyanov, Alexander; Volkl, Martin Andreas; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; Von Haller, Barthelemy; Vorobyev, Ivan; Vranic, Danilo; Vrlakova, Janka; Vulpescu, Bogdan; Wagner, Boris; Wagner, Jan; Wang, Hongkai; Wang, Mengliang; Watanabe, Daisuke; Watanabe, Yosuke; Weber, Michael; Weber, Steffen Georg; Weiser, Dennis Franz; Wessels, Johannes Peter; Westerhoff, Uwe; Whitehead, Andile Mothegi; Wiechula, Jens; Wikne, Jon; Wilk, Grzegorz Andrzej; Wilkinson, Jeremy John; Willems, Guido Alexander; Williams, Crispin; Windelband, Bernd Stefan; Winn, Michael Andreas; Yalcin, Serpil; Yang, Ping; Yano, Satoshi; Yin, Zhongbao; Yokoyama, Hiroki; Yoo, In-Kwon; Yoon, Jin Hee; Yurchenko, Volodymyr; Zaborowska, Anna; Zaccolo, Valentina; Zaman, Ali; Zampolli, Chiara; Correia Zanoli, Henrique Jose; Zaporozhets, Sergey; Zardoshti, Nima; Zarochentsev, Andrey; Zavada, Petr; Zavyalov, Nikolay; Zbroszczyk, Hanna Paulina; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Haitao; Zhang, Xiaoming; Zhang, Yonghong; Chunhui, Zhang; Zhang, Zuman; Zhao, Chengxin; Zhigareva, Natalia; Zhou, Daicui; Zhou, You; Zhou, Zhuo; Zhu, Hongsheng; Zhu, Jianhui; Zichichi, Antonino; Zimmermann, Alice; Zimmermann, Markus Bernhard; Zinovjev, Gennady; Zyzak, Maksym
2017-04-17
The azimuthal correlations of D mesons and charged particles were measured with the ALICE detector in pp collisions at $\\sqrt{s}=7$ TeV and p-Pb collisions at $\\sqrt{s_{\\rm NN}} = 5.02$ TeV at the Large Hadron Collider. D$^0$, D$^+$, and D$^{*+}$ mesons with transverse momentum $3 0.3$ GeV/$c$. The properties of the correlation peak induced by the jet containing the D meson, described in terms of the yield of charged particles in the peak and peak width, are compatible within uncertainties between the two collision systems, and described by Monte-Carlo simulations based on the PYTHIA and POWHEG event generators.
The role of three-gluon correlation functions in the single spin asymmetry
Beppu Hiroo
2015-01-01
Full Text Available We study the twist-3 three-gluon contribution to the single spin asymmetry in the light-hadron production in pp collision in the framework of the collinear factorization. We derive the corresponding cross section formula in the leading order with respect to the QCD coupling constant. We also present a numerical calculation of the asymmetry at the RHIC energy, using a model for the three-gluon correlation functions suggested by the asymmetry for the D-meson production at RHIC. We found that the asymmetries for the light-hadron and the jet productions are very useful to constrain the magnitude and form of the correlation functions. Since the three-gluon correlation functions shift the asymmetry for all kinds of hadrons in the same direction, it is unlikely that they become a main source of the asymmetry.
Algebraic relaxation of a time correlation function
Srivastava, S.; Kumar, C.N.; Tankeshwar, K.
2004-06-01
A second order non-linear differential equation obtained from Mori's integro- differential equation is shown to transform to another form which provides algebraic decay to a time correlation function. Involved parameters in algebraic formula are related to exact properties of the corresponding correlation function. The model has been used to study a sol-gel system which is known, experimentally, to exhibit a power law decay to stress auto-correlation function. The expression obtained for the viscosity shows a logarithmic divergence at some critical value of the parameter. Some features of the model have also been tested using available information about Lennard-Jones fluids. (author)
Holographic picture of heavy vector meson melting
Braga, Nelson R.F.; Diles, Saulo [Universidade Federal do Rio de Janeiro, Instituto de Fisica, Rio de Janeiro, RJ (Brazil); Martin Contreras, Miguel Angel [Universidad de los Andes, High Energy Group, Department of Physics, Bogota (Colombia)
2016-11-15
The fraction of heavy vector mesons produced in a heavy ion collision, as compared to a proton-proton collision, serves as an important indication of the formation of a thermal medium, the quark-gluon plasma. This sort of analysis strongly depends on understanding the thermal effects of a medium like the plasma on the states of heavy mesons. In particular, it is crucial to know the temperature ranges where they undergo a thermal dissociation, or melting. AdS/QCD models are know to provide an important tool for the calculation of hadronic masses, but in general are not consistent with the observation that decay constants of heavy vector mesons decrease with excitation level. It has recently been shown that this problem can be overcome using a soft wall background and introducing an extra energy parameter, through the calculation of correlation functions at a finite position of anti-de Sitter space. This approach leads to the evaluation of masses and decay constants of S wave quarkonium states with just one flavor dependent and one flavor independent parameter. Here we extend this more realistic model to finite temperatures and analyze the thermal behavior of the states 1S, 2S and 3S of bottomonium and charmonium. The corresponding spectral function exhibits a consistent picture for the melting of the states where, for each flavor, the higher excitations melt at lower temperatures. We estimate for these six states the energy ranges in which the heavy vector mesons undergo a transition from a well-defined peak in the spectral function to complete melting in the thermal medium. A very clear distinction between the heavy flavors emerges, with the bottomonium state Υ(1S) surviving a deconfinement transition at temperatures much larger than the critical deconfinement temperature of the medium. (orig.)
Bhatnagar, S.; Mahecha, J.
2008-09-01
We have employed the framework of Bethe-Salpeter equation under Covariant Instantaneous Ansatz to calculate the leptonic decay constants of unequal mass pseudoscalar mesons. In the Dirac structure of BS wave function, the covariants are incorporated from their complete set in accordance with a recently proposed power counting rule, order-by-order in powers of inverse of meson mass. The decay constants are calculated incorporating both Leading Order (LO) as well as Next-to-leading Order (NLO) Dirac covariants. The contribution of both LO as well as NLO covariants to decay constants are studied in detail in this paper. The results are found to improve dramatically, and hence validating the power counting rule which also provides a practical means of incorporating Dirac covariants in the BS wave function of a hadron. (author)
Meson phase space density from interferometry
Bertsch, G.F.
1993-01-01
The interferometric analysis of meson correlations a measure of the average phase space density of the mesons in the final state. The quantity is a useful indicator of the statistical properties of the systems, and it can be extracted with a minimum of model assumptions. Values obtained from recent measurements are consistent with the thermal value, but do not rule out superradiance effects
Sigma meson in heavy ion collision
Cristian, Ivan; Fuchs, Christian
2004-01-01
We want to present a short theoretical prediction of the behaviour of the sigma meson in heavy ion collisions. It is considered that the sigma meson is a pion-pion correlation, resulting from the decay of the N*(1440) resonance. There will be presented some QMD simulations. (authors)
Steffen Strauch
2009-10-01
This is a brief and selective discussion of meson photoproduction measurements with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Meson photo- production is being used as a tool for various investigations, including the spectroscopy of baryons and mesons and the search for vector-meson medium modifications.
Radiative transitions in mesons within a non relativistic quark model
Bonnaz, R.; Silvestre-Brac, B.; Gignoux, C.
2002-01-01
An exhaustive study of radiative transitions in mesons is performed in a non relativistic quark model. Three different types of mesons wave functions are tested. The effect of some usual approximations is commented. Overall agreement with experimental data is obtained
Production and decay rates of the iota meson
Frank, M.; O'Donnell, P.J.; Toronto Univ., Ontario
1984-01-01
We correlate the results for the mass spectrum of low lying isoscalar-pseudoscalar mesons with the production decay rates from J/psi->γP, with P=eta 1 , eta' 1 , eta 2 and iota and study the radiative decays of the iota meson. We conclude that the iota meson has to be interpreted as having a strong gluonium component. (orig.)
Scalar mesons and radiative vector meson decays
Gokalp, A.; Ylmaz, O
2002-01-01
The light scalar mesons with vacuum quantum numbers J p =0 ++ have fundamental importance in understanding low energy QCD phenomenology and the symmetry breaking mechanisms in QCD. The nature and quark substructure of the best known scalar mesons, isoscalar σ(500), f0(980) and isovector a0(980) have been a subject of continuous controversy. The radioactive decay of neutral vector mesons ρ, w and φ into a single photon and a pair of neutral pseudoscalar mesons have been studied in order to obtain information on the nature of these scalar mesons. For such studies, it is essential that a reliable understanding of the mechanisms for these decays should be at hand. In this work, we investigate the particularly interesting mechanism of the exchange of scalar mesons for the radiative vector meson decays by analysing the experimental results such as measured decay rates and invariant mass spectra and compare them with the theoretical prediction of different reaction mechanisms
Generalized hydrodynamic correlations and fractional memory functions
Rodríguez, Rosalio F.; Fujioka, Jorge
2015-12-01
A fractional generalized hydrodynamic (GH) model of the longitudinal velocity fluctuations correlation, and its associated memory function, for a complex fluid is analyzed. The adiabatic elimination of fast variables introduces memory effects in the transport equations, and the dynamic of the fluctuations is described by a generalized Langevin equation with long-range noise correlations. These features motivate the introduction of Caputo time fractional derivatives and allows us to calculate analytic expressions for the fractional longitudinal velocity correlation function and its associated memory function. Our analysis eliminates a spurious constant term in the non-fractional memory function found in the non-fractional description. It also produces a significantly slower power-law decay of the memory function in the GH regime that reduces to the well-known exponential decay in the non-fractional Navier-Stokes limit.
Meson-nucleus potentials and the search for meson-nucleus bound states
Metag, V.; Nanova, M.; Paryev, E. Ya.
2017-11-01
Recent experiments studying the meson-nucleus interaction to extract meson-nucleus potentials are reviewed. The real part of the potentials quantifies whether the interaction is attractive or repulsive while the imaginary part describes the meson absorption in nuclei. The review is focused on mesons which are sufficiently long-lived to potentially form meson-nucleus quasi-bound states. The presentation is confined to meson production off nuclei in photon-, pion-, proton-, and light-ion induced reactions and heavy-ion collisions at energies near the production threshold. Tools to extract the potential parameters are presented. In most cases, the real part of the potential is determined by comparing measured meson momentum distributions or excitation functions with collision model or transport model calculations. The imaginary part is extracted from transparency ratio measurements. Results on K+ ,K0 ,K- , η ,η‧ , ω, and ϕ mesons are presented and compared with theoretical predictions. The interaction of K+ and K0 mesons with nuclei is found to be weakly repulsive, while the K- , η ,η‧ , ω and ϕ meson-nucleus potentials are attractive, however, with widely different strengths. Because of meson absorption in the nuclear medium the imaginary parts of the meson-nucleus potentials are all negative, again with a large spread. An outlook on planned experiments in the charm sector is given. In view of the determined potential parameters, the criteria and chances for experimentally observing meson-nucleus quasi-bound states are discussed. The most promising candidates appear to be the η and η‧ mesons.
Search for rare B meson decays into Ds+ mesons
Albrecht, H.; Ehrlichmann, H.; Hamacher, T.; Hofmann, R.P.; Kirchhoff, T.; Nau, A.; Nowak, S.; Schroeder, H.; Schulz, H.D.; Walter, M.; Wurth, R.; Appuhn, R.D.; Hast, C.; Kolanoski, H.; Lange, A.; Lindner, A.; Mankel, R.; Schieber, M.; Siegmund, T.; Spaan, B.; Thurn, H.; Toepfer, D.; Walther, A.; Wegener, D.; Britton, D.I.; Charlesworth, C.E.K.; Edwards, K.W.; Hyatt, E.R.F.; Kapitza, H.; Krieger, P.; MacFarlane, D.B.; Patel, P.M.; Prentice, J.D.; Saull, P.R.B.; Tzamariudaki, K.; Van de Water, R.G.; Yoon, T.S.; Ressing, D.; Schmidtler, M.; Schneider, M.; Schubert, K.R.; Strahl, K.; Waldi, R.; Weseler, S.; Balagura, V.; Belyaev, I.; Chechelnitsky, S.; Danilov, M.; Droutskoy, A.; Gershtein, Yu.; Golutvin, A.; Gorelov, I.; Kostina, G.; Lubimov, V.; Pakhlov, P.; Ratnikov, F.; Semenov, S.; Shibaev, V.; Soloshenko, V.; Tichomirov, I.; Zaitsev, Yu.
1993-01-01
A search has been performed for rare B meson decays into D s + mesons arising from b→u transitions, W exchange modes, B + annihilation processes, and decays where the D s + is not produced via a W→c anti s quark pair coupling, using the ARGUS detector operating on the Y(4S) resonance at the e + e - storage ring DORIS II. Upper limits for individual decay modes are obtained. In addition, from a study of D s + l - correlations an upper limit of BR(B→D s + l - X)<1.2%(90% CL) is determined. (orig.)
Excited meson radiative transitions from lattice QCD using variationally optimized operators
Shultz, Christian J. [Old Dominion Univ., Norfolk, VA (United States); Dudek, Jozef J. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Old Dominion Univ., Norfolk, VA (United States); Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2015-06-02
We explore the use of 'optimized' operators, designed to interpolate only a single meson eigenstate, in three-point correlation functions with a vector-current insertion. These operators are constructed as linear combinations in a large basis of meson interpolating fields using a variational analysis of matrices of two-point correlation functions. After performing such a determination at both zero and non-zero momentum, we compute three-point functions and are able to study radiative transition matrix elements featuring excited state mesons. The required two- and three-point correlation functions are efficiently computed using the distillation framework in which there is a factorization between quark propagation and operator construction, allowing for a large number of meson operators of definite momentum to be considered. We illustrate the method with a calculation using anisotopic lattices having three flavors of dynamical quark all tuned to the physical strange quark mass, considering form-factors and transitions of pseudoscalar and vector meson excitations. In conclusion, the dependence on photon virtuality for a number of form-factors and transitions is extracted and some discussion of excited-state phenomenology is presented.
Experimental determination of the π meson structure functions by the Drell-Yan mechanism
Badier, J.; Bourotte, J.; Mine, P.; Vanderhaghen, R.; Weisz, S.; Boucrot, J.; Callot, O.; Decamp, D.; Karyotakis, Y.; Lefrancois, J.; Crozon, M.; Delpierre, P.; Leray, T.; Maillard, J.; Tilquin, A.; Valentin, J.
1983-01-01
We have studied high statistics samples of dimuon events (proportional35,000) produced from πsup(+-) on platinum target in the mass interval 4.2 2 sigma/dx 1 dx 2 to π + and π - data. At 200 GeV, the simultaneous use of π + and π - data allows a separate determination of the valence and sea structure functions of the π. Furthermore, the 150 and 280 GeV data allow an accurate determination of the shape of the valence structure function and give an estimate of its evolution between Q 2 =25 and 50 GeV 2 . (orig.)
Correlation functions of two-matrix models
Bonora, L.; Xiong, C.S.
1993-11-01
We show how to calculate correlation functions of two matrix models without any approximation technique (except for genus expansion). In particular we do not use any continuum limit technique. This allows us to find many solutions which are invisible to the latter technique. To reach our goal we make full use of the integrable hierarchies and their reductions which were shown in previous papers to naturally appear in multi-matrix models. The second ingredient we use, even though to a lesser extent, are the W-constraints. In fact an explicit solution of the relevant hierarchy, satisfying the W-constraints (string equation), underlies the explicit calculation of the correlation functions. The correlation functions we compute lend themselves to a possible interpretation in terms of topological field theories. (orig.)
Correlation function of the luminosity distances
Biern, Sang Gyu; Yoo, Jaiyul, E-mail: sgbiern@physik.uzh.ch, E-mail: jyoo@physik.uzh.ch [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich (Switzerland)
2017-09-01
We present the correlation function of the luminosity distances in a flat ΛCDM universe. Decomposing the luminosity distance fluctuation into the velocity, the gravitational potential, and the lensing contributions in linear perturbation theory, we study their individual contributions to the correlation function. The lensing contribution is important at large redshift ( z ∼> 0.5) but only for small angular separation (θ ∼< 3°), while the velocity contribution dominates over the other contributions at low redshift or at larger separation. However, the gravitational potential contribution is always subdominant at all scale, if the correct gauge-invariant expression is used. The correlation function of the luminosity distances depends significantly on the matter content, especially for the lensing contribution, thus providing a novel tool of estimating cosmological parameters.
Correlation functions of Coulomb branch operators
Gerchkovitz, Efrat [Weizmann Institute of Science,Rehovot 76100 (Israel); Gomis, Jaume [Perimeter Institute for Theoretical Physics,Waterloo, ON N2L 2Y5 (Canada); Ishtiaque, Nafiz [Perimeter Institute for Theoretical Physics,Waterloo, ON N2L 2Y5 (Canada); Department of Physics, University of Waterloo,Waterloo, ON N2L 3G1 (Canada); Karasik, Avner; Komargodski, Zohar [Weizmann Institute of Science,Rehovot 76100 (Israel); Pufu, Silviu S. [Joseph Henry Laboratories, Princeton University,Princeton, NJ 08544 (United States)
2017-01-24
We consider the correlation functions of Coulomb branch operators in four-dimensional N=2 Superconformal Field Theories (SCFTs) involving exactly one anti-chiral operator. These extremal correlators are the “minimal' non-holomorphic local observables in the theory. We show that they can be expressed in terms of certain determinants of derivatives of the four-sphere partition function of an appropriate deformation of the SCFT. This relation between the extremal correlators and the deformed four-sphere partition function is non-trivial due to the presence of conformal anomalies, which lead to operator mixing on the sphere. Evaluating the deformed four-sphere partition function using supersymmetric localization, we compute the extremal correlators explicitly in many interesting examples. Additionally, the representation of the extremal correlators mentioned above leads to a system of integrable differential equations. We compare our exact results with previous perturbative computations and with the four-dimensional tt{sup ∗} equations. We also use our results to study some of the asymptotic properties of the perturbative series expansions we obtain in N=2 SQCD.
Generating functional for mesonic ChPT with virtual photons in a general covariant gauge
Agadjanov, Andria; Agadjanov, Dimitri; Khelashvili, Anzor; Rusetsky, Akaki
2013-01-01
The divergent part of the one-loop effective action in Chiral Perturbation Theory with virtual photons has been evaluated in an arbitrary covariant gauge. The differential operator that emerges in the functional determinant is of non-minimal type, for which the standard heat kernel methods are not directly applicable. Both the SU(2) and SU(3) cases have been worked out. A comparison with existing results in the literature is given. (orig.)
Factorization and shape-function effects in inclusive B-meson decays
Bosch, S.W.; Lange, B.O.; Neubert, M.; Paz, G.
2004-01-01
Using methods of effective field theory, factorized expressions for arbitrary B-bar ->Xul-ν-bar decay distributions in the shape-function region of large hadronic energy and moderate hadronic invariant mass are derived. Large logarithms are resummed at next-to-leading order in renormalization-group improved perturbation theory. The operator product expansion is employed to relate moments of the renormalized shape function with HQET parameters such as mb, Λ-bar and λ1 defined in a new physical subtraction scheme. An analytic expression for the asymptotic behavior of the shape function is obtained, which reveals that it is not positive definite. Explicit expressions are presented for the charged-lepton energy spectrum, the hadronic invariant mass distribution, and the spectrum in the hadronic light-cone momentum P+=EH-|P->H|. A new method for a precision measurement of |Vub| is proposed, which combines good theoretical control with high efficiency and a powerful discrimination against charm background
Locality of correlation in density functional theory
Burke, Kieron [Department of Chemistry, University of California, Irvine, California 92697 (United States); Cancio, Antonio [Department of Physics and Astronomy, Ball State University, Muncie, Indiana 47306 (United States); Gould, Tim [Qld Micro- and Nanotechnology Centre, Griffith University, Nathan, Qld 4111 (Australia); Pittalis, Stefano [CNR-Istituto di Nanoscienze, Via Campi 213A, I-41125 Modena (Italy)
2016-08-07
The Hohenberg-Kohn density functional was long ago shown to reduce to the Thomas-Fermi (TF) approximation in the non-relativistic semiclassical (or large-Z) limit for all matter, i.e., the kinetic energy becomes local. Exchange also becomes local in this limit. Numerical data on the correlation energy of atoms support the conjecture that this is also true for correlation, but much less relevant to atoms. We illustrate how expansions around a large particle number are equivalent to local density approximations and their strong relevance to density functional approximations. Analyzing highly accurate atomic correlation energies, we show that E{sub C} → −A{sub C} ZlnZ + B{sub C}Z as Z → ∞, where Z is the atomic number, A{sub C} is known, and we estimate B{sub C} to be about 37 mhartree. The local density approximation yields A{sub C} exactly, but a very incorrect value for B{sub C}, showing that the local approximation is less relevant for the correlation alone. This limit is a benchmark for the non-empirical construction of density functional approximations. We conjecture that, beyond atoms, the leading correction to the local density approximation in the large-Z limit generally takes this form, but with B{sub C} a functional of the TF density for the system. The implications for the construction of approximate density functionals are discussed.
The statistics of galaxies: beyond correlation functions
Lachieze-Rey, M.
1988-01-01
I mention some normalization problems encountered when estimating the 2-point correlation functions in samples of galaxies of different average densities. I present some aspects of the void probability function as a statistical indicator, free of such normalization problems. Finally I suggest a new statistical approach to give an account in a synthetic way of those aspects of the galaxy distribution that a conventional method is unable to characterize
Discussion of the 3P0 model applied to the decay of mesons into two mesons
Bonnaz, R.; Silvestre-Brac, B.
1999-01-01
The 3 P 0 model for the decay of a meson into two mesons is revisited. In particular, the formalism is extended in order to deal with an arbitrary form for the creation vertex and with the exact meson wave functions. A careful analysis of both effects is performed and discussed. The model is then applied to a large class of transitions known experimentally. Two types of quark-antiquark potentials have been tested and compared. (author)
Analyzing correlation functions with tesseral and Cartesian spherical harmonics
Danielewicz, Pawel; Pratt, Scott
2007-01-01
The dependence of interparticle correlations on the orientation of particle relative momentum can yield unique information on the space-time features of emission in reactions with multiparticle final states. In the present paper, the benefits of a representation and analysis of the three-dimensional correlation information in terms of surface spherical harmonics is presented. The harmonics include the standard complex tesseral harmonics and the real Cartesian harmonics. Mathematical properties of the lesser known Cartesian harmonics are illuminated. The physical content of different angular harmonic components in a correlation is described. The resolving power of different final-state effects with regard to determining angular features of emission regions is investigated. The considered final-state effects include identity interference, strong interactions, and Coulomb interactions. The correlation analysis in terms of spherical harmonics is illustrated with the cases of Gaussian and blast-wave sources for proton-charged meson and baryon-baryon pairs
Non-Parametric Estimation of Correlation Functions
Brincker, Rune; Rytter, Anders; Krenk, Steen
In this paper three methods of non-parametric correlation function estimation are reviewed and evaluated: the direct method, estimation by the Fast Fourier Transform and finally estimation by the Random Decrement technique. The basic ideas of the techniques are reviewed, sources of bias are point...
Integral equations of hadronic correlation functions a functional- bootstrap approach
Manesis, E K
1974-01-01
A reasonable 'microscopic' foundation of the Feynman hadron-liquid analogy is offered, based on a class of models for hadron production. In an external field formalism, the equivalence (complementarity) of the exclusive and inclusive descriptions of hadronic reactions is specifically expressed in a functional-bootstrap form, and integral equations between inclusive and exclusive correlation functions are derived. Using the latest CERN-ISR data on the two-pion inclusive correlation function, and assuming rapidity translational invariance for the exclusive one, the simplest integral equation is solved in the 'central region' and an exclusive correlation length in rapidity predicted. An explanation is also offered for the unexpected similarity observed between pi /sup +/ pi /sup -/ and pi /sup -/ pi /sup -/ inclusive correlations. (31 refs).
A pair density functional theory utilizing the correlated wave function
Higuchi, M; Higuchi, K
2009-01-01
We propose a practical scheme for calculating the ground-state pair density (PD) by utilizing the correlated wave function. As the correlated wave function, we adopt a linear combination of the single Slater determinants that are constructed from the solutions of the initial scheme [Higuchi M and Higuchi K 2007 Physica B 387, 117]. The single-particle equation is derived by performing the variational principle within the set of PDs that are constructed from such correlated wave functions. Since the search region of the PD is substantially extended as compared with the initial scheme, it is expected that the present scheme can cover more correlation effects. The single-particle equation is practical, and may be easily applied to actual calculations.
Non-perturbative QCD correlation functions
Cyrol, Anton Konrad
2017-11-27
Functional methods provide access to the non-perturbative regime of quantum chromo- dynamics. Hence, they allow investigating confinement and chiral symmetry breaking. In this dissertation, correlation functions of Yang-Mills theory and unquenched two-flavor QCD are computed from the functional renormalization group. Employing a self-consistent vertex expansion of the effective action, Yang-Mills correlation functions are obtained in four as well as in three spacetime dimensions. To this end, confinement and Slavnov-Taylor identities are discussed. Our numerical results show very good agreement with corresponding lattice results. Next, unquenched two-flavor QCD is considered where it is shown that the unquenched two-flavor gluon propagator is insensitive to the pion mass. Furthermore, the necessity for consistent truncations is emphasized. Finally, correlation functions of finite-temperature Yang-Mills theory are computed in a truncation that includes the splitting of the gluon field into directions that are transverse and longitudinal to the heat bath. In particular, it includes the splitting of the three- and four-gluon vertices. The obtained gluon propagator allows to extract a Debye screening mass that coincides with the hard thermal loop screening mass at high temperatures, but is meaningful also at temperatures below the phase transition temperature.
Mass spectrum of 1-+ exotic mesons from lattice QCD
Cook, M. S.; Fiebig, H. R.
2006-01-01
Time correlation functions of a hybrid exotic meson operator, with J PC =1 -+ , generated in quenched lattice QCD are subjected to a (Bayesian) maximum entropy analysis. Five distinct spectral levels are uncovered. Their extrapolation into the physical pion mass region suggests a possible relationship to experimentally known states π 1 (1400) and π 1 (1600), and also to a state in the 2 GeV region carrying the same quantum numbers
Adam, J. [Czech Technical Univ., Prague (Czech Republic). Faculty of Nuclear Sciences and Physical Engineering; Adamova, D. [Academy of Sciences of the Czech Republic, Rez u Prahy (Czech Republic). Nuclear Physics Inst.; Aggarwal, M.M. [Panjab Univ., Chandigarh (India). Physics Dept.; Collaboration: ALICE Collaboration; and others
2017-04-15
The azimuthal correlations of D mesons with charged particles were measured with the ALICE apparatus in pp collisions at √(s) = 7 TeV and p-Pb collisions at √(s{sub NN}) = 5.02 TeV at the Large Hadron Collider. D{sup 0}, D{sup +}, and D{sup *+} mesons and their charge conjugates with transverse momentum 3 < p{sub T} < 16 GeV/c and rapidity in the nucleon-nucleon centre-of-mass system vertical stroke y{sub cms} vertical stroke < 0.5 (pp collisions) and -0.96 < y{sub cms} < 0.04 (p-Pb collisions) were correlated to charged particles with p{sub T} > 0.3GeV/c. The yield of charged particles in the correlation peak induced by the jet containing the D meson and the peak width are compatible within uncertainties in the two collision systems. The data are described within uncertainties by Monte-Carlo simulations based on PYTHIA, POWHEG, and EPOS 3 event generators. (orig.)
Abelev, B.; Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Barnby, L. S.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bombara, M.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chatterjee, A.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Gaillard, L.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, B.; Huang, X.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jentsch, A.; Jia, J.; Jiang, K.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, C.; Li, Y.; Li, W.; Li, X.; Li, X.; Lin, T.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, L.; Ma, R.; Ma, G. L.; Ma, Y. G.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Matis, H. S.; McDonald, D.; McKinzie, S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nattrass, C.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, Z.; Sun, X. M.; Surrow, B.; Svirida, D. N.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, H.; Wang, Y.; Wang, G.; Wang, Y.; Wang, J. S.; Wang, F.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xin, K.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Xu, J.; Xu, H.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, S.; Yang, Y.; Yang, Y.; Yang, C.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, S.; Zhang, J. B.; Zhang, J.; Zhang, J.; Zhang, Z.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration
2016-07-01
We present measurements of the near side of triggered di-hadron correlations using neutral strange baryons (Λ ,Λ ¯) and mesons (KS0) at intermediate transverse momentum (3 < pT <6 GeV /c ) to look for possible flavor and baryon-meson dependence. This study is performed in d +Au , Cu+Cu, and Au+Au collisions at √{sN N}=200 GeV measured by the STAR experiment at RHIC. The near-side di-hadron correlation contains two structures, a peak which is narrow in azimuth and pseudorapidity consistent with correlations from jet fragmentation, and a correlation in azimuth which is broad in pseudorapidity. The particle composition of the jet-like correlation is determined using identified associated particles. The dependence of the conditional yield of the jet-like correlation on the trigger particle momentum, associated particle momentum, and centrality for correlations with unidentified trigger particles are presented. The neutral strange particle composition in jet-like correlations with unidentified charged particle triggers is not well described by PYTHIA. However, the yield of unidentified particles in jet-like correlations with neutral strange particle triggers is described reasonably well by the same model.
Meson spectroscopy, quark mixing and quantum chromodynamics
Filippov, A.T.
1979-01-01
A semiphenomenological theory of mass spectrum for mesons, consisting of a quark-antiquark pair, is presented. Relativistic kinematical effects of the quark mass differences, the SU(3)-symmetry breaking in slopes of the Regge trajectories and in radially excited states are taken into account. The OZI-rule breaking is taken into account by means of the mixing matrix for the quark wave functions, whose form is suggested by the quantum chromodynamics. A simple extrapolation of expression, given by the quantum chromodynamics from the ''asymptotic freedom'' region to the ''infrared slavery'' region is proposed to describe the dependence of the mixing parameters on the meson masses. To calculate masses and mixing angles for pseudoscalar mesons a condition is proposed that the pion mass is minimal. In this situation the eta-meson mass is near the maximal value. The predictions of the theory for masses and mixing angles of the mesons are in good agreement with the experiment
Multiple soft limits of cosmological correlation functions
Joyce, Austin; Khoury, Justin; Simonović, Marko
2015-01-01
We derive novel identities satisfied by inflationary correlation functions in the limit where two external momenta are taken to be small. We derive these statements in two ways: using background-wave arguments and as Ward identities following from the fixed-time path integral. Interestingly, these identities allow us to constrain some of the O(q 2 ) components of the soft limit, in contrast to their single-soft analogues. We provide several nontrivial checks of our identities both in the context of resonant non-Gaussianities and in small sound speed models. Additionally, we extend the relation at lowest order in external momenta to arbitrarily many soft legs, and comment on the many-soft extension at higher orders in the soft momentum. Finally, we consider how higher soft limits lead to identities satisfied by correlation functions in large-scale structure
Redshift distortions of galaxy correlation functions
Fry, J.N.; Florida Univ., Gainesville, FL; Gaztanaga, E.; Oxford Univ.
1993-01-01
To examine how peculiar velocities can affect the 2-, 3-, and 4-point correlation functions, we evaluate volume-average correlations for configurations that emphasize and minimize distortions for four different volume-limited samples from each of the CfA, SSRS, and IRAS redshift catalogs. We present the results as the correlation length r 0 and power index γ of the 2-point correlation, anti Ξ 2 = (r 0 /r) γ , and as the hierarchical amplitudes of the 3- and 4-point functions, S 3 = anti Ξ 3 /anti Ξ 2 2 and S 4 = anti Ξ/anti Ξ 2 3 . We find a characteristic distortion for anti Ξ 2 : The slope γ is flatter and the correlation length is larger in redshift space than in real space; that is, redshift distortions ''move'' correlations from small to large scales. At the largest scales, extra power in the redshift distribution is compatible with Ω 4/7 /b ∼ 1; we find 0.53 ± 0.15, 1.10 ± 0.16 and 0.84 ± 0.45 for the CfA, SSRS and IRAS catalogs. Higher order correlations anti Ξ 3 and anti Ξ 4 suffer similar redshift distortions, but in such a way that, within the accuracy of our analysis, the normalized amplitudes S 3 and S 4 are insensitive to this effect. The hierarchical amplitudes S 3 and S 4 are constant as a function of scale between 1-12 h -1 Mpc and have similar values in all samples and catalogues, S 3 ∼ 2 and S 4 ∼ 6, despite the fact that anti Ξ 2 , anti Ξ 3 , and anti Ξ 4 differ from one sample to another by large factors. The agreement between the independent estimations of S 3 and S 4 is remarkable given the different criteria in the selection of galaxies and also the difference in the resulting range of densities, luminosities and locations between samples
Meson exchange corrections in deep inelastic scattering on deuteron
Kaptari, L.P.; Titov, A.I.
1989-01-01
Starting with the general equations of motion of the nucleons interacting with the mesons the one-particle Schroedinger-like equation for the nucleon wave function and the deep inelastic scattering amplitude with the meson-exchange currents are obtained. Effective pion-, sigma-, and omega-meson exchanges are considered. It is found that the mesonic corrections only partially (about 60%) restore the energy sum rule breaking because of the nucleon off-mass-shell effects in nuclei. This results contradicts with the prediction based on the calculation of the energy sum rule limited by the second order of the nucleon-meson vertex and static approximation. 17 refs.; 3 figs
Correlation Functions in Holographic Minimal Models
Papadodimas, Kyriakos
2012-01-01
We compute exact three and four point functions in the W_N minimal models that were recently conjectured to be dual to a higher spin theory in AdS_3. The boundary theory has a large number of light operators that are not only invisible in the bulk but grow exponentially with N even at small conformal dimensions. Nevertheless, we provide evidence that this theory can be understood in a 1/N expansion since our correlators look like free-field correlators corrected by a power series in 1/N . However, on examining these corrections we find that the four point function of the two bulk scalar fields is corrected at leading order in 1/N through the contribution of one of the additional light operators in an OPE channel. This suggests that, to correctly reproduce even tree-level correlators on the boundary, the bulk theory needs to be modified by the inclusion of additional fields. As a technical by-product of our analysis, we describe two separate methods -- including a Coulomb gas type free-field formalism -- that ...
New angles on energy correlation functions
Moult, Ian; Necib, Lina; Thaler, Jesse
2016-12-01
Jet substructure observables, designed to identify specific features within jets, play an essential role at the Large Hadron Collider (LHC), both for searching for signals beyond the Standard Model and for testing QCD in extreme phase space regions. In this paper, we systematically study the structure of infrared and collinear safe substructure observables, defining a generalization of the energy correlation functions to probe n-particle correlations within a jet. These generalized correlators provide a flexible basis for constructing new substructure observables optimized for specific purposes. Focusing on three major targets of the jet substructure community — boosted top tagging, boosted W/Z/H tagging, and quark/gluon discrimination — we use power-counting techniques to identify three new series of powerful discriminants: M i , N i , and U i . The M i series is designed for use on groomed jets, providing a novel example of observables with improved discrimination power after the removal of soft radiation. The N i series behave parametrically like the N -subjettiness ratio observables, but are defined without respect to subjet axes, exhibiting improved behavior in the unresolved limit. Finally, the U i series improves quark/gluon discrimination by using higher-point correlators to simultaneously probe multiple emissions within a jet. Taken together, these observables broaden the scope for jet substructure studies at the LHC.
New angles on energy correlation functions
Moult, Ian [Berkeley Center for Theoretical Physics, University of California,Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory,Berkeley, CA 94720 (United States); Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States); Necib, Lina; Thaler, Jesse [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States)
2016-12-29
Jet substructure observables, designed to identify specific features within jets, play an essential role at the Large Hadron Collider (LHC), both for searching for signals beyond the Standard Model and for testing QCD in extreme phase space regions. In this paper, we systematically study the structure of infrared and collinear safe substructure observables, defining a generalization of the energy correlation functions to probe n-particle correlations within a jet. These generalized correlators provide a flexible basis for constructing new substructure observables optimized for specific purposes. Focusing on three major targets of the jet substructure community — boosted top tagging, boosted W/Z/H tagging, and quark/gluon discrimination — we use power-counting techniques to identify three new series of powerful discriminants: M{sub i}, N{sub i}, and U{sub i}. The M{sub i} series is designed for use on groomed jets, providing a novel example of observables with improved discrimination power after the removal of soft radiation. The N{sub i} series behave parametrically like the N-subjettiness ratio observables, but are defined without respect to subjet axes, exhibiting improved behavior in the unresolved limit. Finally, the U{sub i} series improves quark/gluon discrimination by using higher-point correlators to simultaneously probe multiple emissions within a jet. Taken together, these observables broaden the scope for jet substructure studies at the LHC.
Structure functions and correlations in nuclei
Schiavilla, R.; Lewart, D.S.; Pandharipande, V.R.
1987-01-01
The static longitudinal structure function S l (k) and the static structure function S(k) of 3 H, 3 He and 4 He nuclei and nuclear matter are calculated using realistic wave functions obtained from Faddeev and variational calculations. In order to study the variation of the structure function with the number of particles in the system we also calculate S(k) of atomic helium liquid drops containing 4, 8, 20, 40, 70, 168 and 240 atoms. Monte Carlo integration is used to calculate the structure functions of finite systems, while those of nuclear matter are calculated with chain summation methods. The behaivior of S(k) and S l (k) at small values of k is discussed. We find that the recent Saclay data on S l (k) of the 3 He nucleus are in agreement with theory. Though the data indicate the the existence of correlations between the two protons in the 3 He nucleus, they are not accurate enough to draw interesting conclusions about the repulsive core in the nucleon-nucleon interaction. The structure functions of atomic helium liquid drops indicate a smooth variation of S(k) with the number of atoms in the drop. The S L (k) of the 4 He nucleus and nuclear matter are very similar for k > 1.5 fm -1 , and it appears plausible that S L (k) of nuclei having A > 3 may not depend significantly on A when k > 1.5 fm -1 . (orig.)
The interpretation of the iota meson
Frank, M.
1985-01-01
The authors analyze the iota (1440) meson in a non-relativistic quark model. The authors review the experimental data, then attempt to incorporate it in the mass spectrum and radiative decays of the low-lying pseudoscalar and vector mesons. Correlating these results with production decay rates from J/psi and the radiative decays of iota, the authors conclude that the iota has to be interpreted as having a strong gluonium component
Correlation functional in screened-exchange density functional theory procedures.
Chan, Bun; Kawashima, Yukio; Hirao, Kimihiko
2017-10-15
In the present study, we have explored several prospects for the further development of screened-exchange density functional theory (SX-DFT) procedures. Using the performance of HSE06 as our measure, we find that the use of alternative correlation functionals (as oppose to PBEc in HSE06) also yields adequate results for a diverse set of thermochemical properties. We have further examined the performance of new SX-DFT procedures (termed HSEB-type methods) that comprise the HSEx exchange and a (near-optimal) reparametrized B97c (c OS,0 = c SS,0 = 1, c OS,1 = -1.5, c OS,2 = -0.644, c SS,1 = -0.5, and c SS,2 = 1.10) correlation functionals. The different variants of HSEB all perform comparably to or slightly better than the original HSE-type procedures. These results, together with our fundamental analysis of correlation functionals, point toward various directions for advancing SX-DFT methods. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Fock exchange in meson theories of nuclei
Bolsterli, M.
1986-01-01
The Fock exchange term in meson field theories of nuclear systems is shown to arise from a two-loop ground-state self-energy diagram. Evaluation of this diagram gives the relativistic or semirelativistic analog of the Fock exchange energy; it differs from the nucleon-nucleon Fock energy in including retardation effects. In finite meson-field theories of nuclear systems, the variational nature of the meson-field analog of the Hartree-Fock energy functional can be further elucidated. 4 refs
Quark condensate contributions to the gluon self-energy and the ρ meson sum rule
Steele, T.G.
1989-01-01
The operator-product expansion will be employed to obtain the lowest-order, quark condensate component of both the gluon self-energy and the ρ meson correlation function to all orders in the quark mass parameter. Field-theoretic aspects of the self-energy and correlation function will be considered, and physical effects to the quark condensate upon gluon mass generation will be examined. (orig.)
Two-point correlation function for Dirichlet L-functions
Bogomolny, E.; Keating, J. P.
2013-03-01
The two-point correlation function for the zeros of Dirichlet L-functions at a height E on the critical line is calculated heuristically using a generalization of the Hardy-Littlewood conjecture for pairs of primes in arithmetic progression. The result matches the conjectured random-matrix form in the limit as E → ∞ and, importantly, includes finite-E corrections. These finite-E corrections differ from those in the case of the Riemann zeta-function, obtained in Bogomolny and Keating (1996 Phys. Rev. Lett. 77 1472), by certain finite products of primes which divide the modulus of the primitive character used to construct the L-function in question.
Two-point correlation function for Dirichlet L-functions
Bogomolny, E; Keating, J P
2013-01-01
The two-point correlation function for the zeros of Dirichlet L-functions at a height E on the critical line is calculated heuristically using a generalization of the Hardy–Littlewood conjecture for pairs of primes in arithmetic progression. The result matches the conjectured random-matrix form in the limit as E → ∞ and, importantly, includes finite-E corrections. These finite-E corrections differ from those in the case of the Riemann zeta-function, obtained in Bogomolny and Keating (1996 Phys. Rev. Lett. 77 1472), by certain finite products of primes which divide the modulus of the primitive character used to construct the L-function in question. (paper)
Yamazaki, T.; Nagamine, K.
1992-01-01
Unstable particles such as mesons and muons are now used in various research domains of physics, chemistry, engineering, and life sciences. This book is aimed at summarizing the present exploratory activities and giving future perspectives from a very broad scope. It contains 27 contributions in a wide range of subjects, such as μSR studies of superconductivities, magnetism, muon beam and μSr methodology, theoretical accounts of muon hyperfine interactions, muon catalyzed fusion processes, metastable exotic atoms, medical diagnostics, strangeness nuclear physics, mesons in nuclei, meson-related nuclear reactions and structure, and exotic decays of mesons
Lattice study of D and D{sub s} meson form factors with twisted boundary conditions
Li, Ning; Wu, Ya-Jie [Xi' an Technological University, School of Science, Xi' an (China)
2017-03-15
We present results on the D and D{sub s} meson electromagnetic form factors using N{sub f} = 2 twisted mass Lattice Quantum Chromodynamics (LQCD) gauge configurations. In this simulation, to access spatial components of momenta that are different from the integer multiples of 2π/L, we apply twisted boundary conditions to compute corresponding correlation functions. Electromagnetic form factors with more small four-momentum transfer are determined, and further we fit the electromagnetic charge radius for D and D{sub s} mesons, respectively. (orig.)
Relations between correlation functions in gauge field theory
Simonov, Yu. A.; Shevchenko, V. I.
1997-01-01
Exact relations between vacuum correlations of non-Abelian field strengths are obtained. With the aid of exterior differentiation, the invariant parts of a given correlation function are expressed in terms of higher order correlation functions. The corollaries of these relations for the behavior of nonperturbative correlation functions at small and large distances are deduced
Pseudoscalar Meson Electroproduction and Transversity
Goldstein, G.; Liuti, S.
2011-01-01
Exclusive meson leptoproduction from nucleons in the deeply virtual exchanged boson limit can be described by generalized parton distributions (GPDs). Including spin dependence in the description requires 8 independent quark-parton and gluon-parton functions. The chiral even subset of 4 quark-nucleon GPDs are related to nucleon form factors and to parton distribution functions. The chiral odd set of 4 quark-nucleon GPDs are related to transversity, the tensor charge, and other quantities related to transversity. Different meson or photon production processes access different combinations of GPDs. This is analyzed in terms of t-channel exchange quantum numbers, J PC and it is shown that pseudoscalar production can isolate chiral odd GPDs. There is a sensitive dependence in various cross sections and asymmetries on the tensor charge of the nucleon and other transversity parameters. In a second section, analyticity and completeness are shown to limit the partonic interpret ation of the GPDs in the ERBL region.
Two-proton correlation function: a gentle introduction
Deloff, A.
2007-01-01
The recent COSY-11 collaboration measurement of the two-proton correlation function in the pp→ppη reaction, reported at this meeting [1], arouse some interest in a simple theoretical description of the correlation function. In these notes we present a pedagogical introduction to the practical methods that can be used for calculating the correlation function
On the spin-parity of a E(1420) meson
Asatryan, G.M.; Zaslavskij, A.N.
1977-01-01
The phenomenological analysis of data on the E(1420)-meson decay is carried out. The Adair distribution are constructed for the decays E→deltaπ, K* anti K(antiK*K), K anti K π, νππ in different reactions: the correlations in which the spin of E-meson is most explicitely manifested are marked
Temperature-dependent cross sections for meson-meson nonresonant reactions in hadronic matter
Zhang Yiping; Xu Xiaoming; Ge Huijun
2010-01-01
We present a potential of which the short-distance part is given by one gluon exchange plus perturbative one- and two-loop corrections and of which the large-distance part exhibits a temperature-dependent constant value. The Schroedinger equation with this temperature-dependent potential yields a temperature dependence of the mesonic quark-antiquark relative-motion wave function and of meson masses. The temperature dependence of the potential, the wave function and the meson masses brings about temperature dependence of cross sections for the nonresonant reactions ππ→ρρ for I=2, KK→K*K* for I=1, KK*→K*K* for I=1, πK→ρK* for I=3/2, πK*→ρK* for I=3/2, ρK→ρK* for I=3/2 and πK*→ρK for I=3/2. As the temperature increases, the rise or fall of peak cross sections is determined by the increased radii of initial mesons, the loosened bound states of final mesons, and the total-mass difference of the initial and final mesons. The temperature-dependent cross sections and meson masses are parametrized.
Vector-meson dominance revisited
Terschlüsen Carla
2012-12-01
Full Text Available The interaction of mesons with electromagnetism is often well described by the concept of vector-meson dominance (VMD. However, there are also examples where VMD fails. A simple chiral Lagrangian for pions, rho and omega mesons is presented which can account for the respective agreement and disagreement between VMD and phenomenology in the sector of light mesons.
Structuring Stokes correlation functions using vector-vortex beam
Kumar, Vijay; Anwar, Ali; Singh, R. P.
2018-01-01
Higher order statistical correlations of the optical vector speckle field, formed due to scattering of a vector-vortex beam, are explored. Here, we report on the experimental construction of the Stokes parameters covariance matrix, consisting of all possible spatial Stokes parameters correlation functions. We also propose and experimentally realize a new Stokes correlation functions called Stokes field auto correlation functions. It is observed that the Stokes correlation functions of the vector-vortex beam will be reflected in the respective Stokes correlation functions of the corresponding vector speckle field. The major advantage of proposing Stokes correlation functions is that the Stokes correlation function can be easily tuned by manipulating the polarization of vector-vortex beam used to generate vector speckle field and to get the phase information directly from the intensity measurements. Moreover, this approach leads to a complete experimental Stokes characterization of a broad range of random fields.
Spin O decay angular distribution for interfering mesons in electroproduction
Funsten, H.; Gilfoyle, G.
1994-04-01
Self analyzing meson electroproduction experiments are currently being planned for the CEBAF CLAS detector. These experiments deduce the spin polarization of outgoing unstable spin s (?)0 mesons from their decay angular distribution, W({theta},{psi}). The large angular acceptance of the CLAS detector permits kinematic tracking of a sufficient number of these events to accurately determine electroproduction amplitudes from the deduced polarization. Maximum polarization information is obtained from W({theta},{psi}) for decay into spin 0 daughters. The helicity of the decaying meson is transferred to the daughter`s relative orbital angular momentum m-projection; none is {open_quotes}absorbed{close_quotes} into daughter helicities. The decaying meson`s helicity maximally appears in W({theta},{psi}). W({theta},{psi}) for spin 0 daughters has been derived for (1) vector meson electroproduction and (2) general interfering mesons produced by incident pions. This paper derives W({theta},{psi}) for electroproduction of two interfering mesons that decay into spin 0 daughters. An application is made to the case of interfering scalar and vector mesons. The derivation is an extension of work by Schil using the general decay formalism of Martin. The expressions can be easily extended to the case of N interfering mesons since interference occurs pairwise in the observable W ({theta},{psi}), a quadratic function of the meson amplitudes. The derivation uses the virtual photon density matrix of Schil which is transformed by a meson electroproduction transition operator, T. The resulting density matrix for the interfering mesons is then converted into a corresponding statistical tensor and contracted into the efficiency tensor for spin 0 daughters.
Rho, M.
1981-01-01
Quantum chromodynamics is believed to be candidate theory for the strong interactions and contains as its ingredients spinor quark fields and vector gluons, none of which can perhaps be ever liberated and detected in laboratories. A nucleus consists of nucleons bound by nuclear force which are however separately observable and which seem to preserve their identities even under extreme conditions. An intriguing question is: when compressed to high densities or heated to high temperature, at what point does a nuclear matter cease to be describable in terms of nucleon and meson degrees of freedom, but become a plasma of quarks and gluons; and how does this transition occur. This is not an idle question. If quarks and gluons are never to be observed isolated, then it may be that at low energies (or at low densities) they are not the right variables to do physics with. Instead hadrons must be. On the other hand, asymptotic freedom - the unique property of non-abelian gauge theories to which QCD belongs that quark-gluon and gluon-gluon interactions get weaker at short distances - tells us that at some large matter density the matter must necessarily be in the form of quark gas interacting only weakly. This means that a change in degrees of freedom must take place. We would like to know where this occurs and how. In this talk, I would like to address to this question by discussing first the large success we have had in understanding the role that mesons play in finite nuclei and nuclear matter and then attempting to correlate nucleon and meson degrees of freedom to quark-gluon degrees of freedom. In my opinion we are now at a stage where we feel fairly confident in our understanding of nucleon-meson structure of nuclei and nuclear matter and any further progress in deeper understanding of nuclear dynamics - and strong interactions - must come from QCD or its effective version, bags or strings. (orig.)
Rahmani, S.; Hassanabadi, H. [Shahrood University of Technology, Physics Department, Shahrood (Iran, Islamic Republic of)
2017-09-15
Employing generalized quantum isotonic oscillator potential we determine wave function for mesonic system in nonrelativistic formalism. Then we investigate branching ratios of leptonic decays for heavy-light mesons including a charm quark. Next, by applying the Isgur-Wise function we obtain branching ratios of semileptonic decays for mesons including a bottom quark. The weak decay of the B{sub c} meson is also analyzed to study the life time. Comparison with other available theoretical approaches is presented. (orig.)
Memory functions and correlations in additive binary Markov chains
Melnyk, S S; Usatenko, O V; Yampol'skii, V A; Apostolov, S S; Maiselis, Z A
2006-01-01
A theory of additive Markov chains with a long-range memory, proposed earlier in Usatenko et al (2003 Phys. Rev. E 68 061107), is developed and used to describe statistical properties of long-range correlated systems. The convenient characteristics of such systems, memory functions and their relation to the correlation properties of the systems are examined. Various methods for finding the memory function via the correlation function are proposed. The inverse problem (calculation of the correlation function by means of the prescribed memory function) is also solved. This is demonstrated for the analytically solvable model of the system with a step-wise memory function
Memory functions and correlations in additive binary Markov chains
Melnyk, S S [A Ya Usikov Institute for Radiophysics and Electronics, Ukrainian Academy of Science, 12 Proskura Street, 61085 Kharkov (Ukraine); Usatenko, O V [A Ya Usikov Institute for Radiophysics and Electronics, Ukrainian Academy of Science, 12 Proskura Street, 61085 Kharkov (Ukraine); Yampol' skii, V A [A Ya Usikov Institute for Radiophysics and Electronics, Ukrainian Academy of Science, 12 Proskura Street, 61085 Kharkov (Ukraine); Apostolov, S S [V N Karazin Kharkov National University, 4 Svoboda Sq., Kharkov 61077 (Ukraine); Maiselis, Z A [V N Karazin Kharkov National University, 4 Svoboda Sq., Kharkov 61077 (Ukraine)
2006-11-17
A theory of additive Markov chains with a long-range memory, proposed earlier in Usatenko et al (2003 Phys. Rev. E 68 061107), is developed and used to describe statistical properties of long-range correlated systems. The convenient characteristics of such systems, memory functions and their relation to the correlation properties of the systems are examined. Various methods for finding the memory function via the correlation function are proposed. The inverse problem (calculation of the correlation function by means of the prescribed memory function) is also solved. This is demonstrated for the analytically solvable model of the system with a step-wise memory function.
Butler, J.N.; Shukla, S.
1995-05-01
The experimental status of excited charmed mesons is reviewed and is compared to theoretical expectations. Six states have been observed and their properties are consistent with those predicted for excited charmed states with orbital angular momentum equal to one
Hybrid mesons with auxiliary fields
Buisseret, F.; Mathieu, V.
2006-01-01
Hybrid mesons are exotic mesons in which the color field is not in the ground state. Their understanding deserves interest from a theoretical point of view, because it is intimately related to nonperturbative aspects of QCD. Moreover, it seems that some recently detected particles, such as the π 1 (1600) and the Y(4260), are serious hybrid candidates. In this work, we investigate the description of such exotic hadrons by applying the auxiliary fields technique (also known as the einbein field method) to the widely used spinless Salpeter Hamiltonian with appropriate linear confinement. Instead of the usual numerical resolution, this technique allows to find simplified analytical mass spectra and wave functions of the Hamiltonian, which still lead to reliable qualitative predictions. We analyse and compare two different descriptions of hybrid mesons, namely a two-body q system with an excited flux tube, or a three-body qg system. We also compute the masses of the 1 -+ hybrids. Our results are shown to be in satisfactory agreement with lattice QCD and other effective models. (orig.)
A cumulant functional for static and dynamic correlation
Hollett, Joshua W.; Hosseini, Hessam; Menzies, Cameron
2016-01-01
A functional for the cumulant energy is introduced. The functional is composed of a pair-correction and static and dynamic correlation energy components. The pair-correction and static correlation energies are functionals of the natural orbitals and the occupancy transferred between near-degenerate orbital pairs, rather than the orbital occupancies themselves. The dynamic correlation energy is a functional of the statically correlated on-top two-electron density. The on-top density functional used in this study is the well-known Colle-Salvetti functional. Using the cc-pVTZ basis set, the functional effectively models the bond dissociation of H 2 , LiH, and N 2 with equilibrium bond lengths and dissociation energies comparable to those provided by multireference second-order perturbation theory. The performance of the cumulant functional is less impressive for HF and F 2 , mainly due to an underestimation of the dynamic correlation energy by the Colle-Salvetti functional.
QCD vacuum tensor susceptibility and properties of transversely polarized mesons
Bakulev, A.P.; Mikhajlov, S.V.
1999-01-01
We re-estimate the tensor susceptibility of QCD vacuum, χ, and to this end, we re-estimate the leptonic decay constants for transversely polarized ρ-, ρ'- and b 1 -mesons. The origin of the susceptibility is analyzed using duality between ρ- and b 1 -channels in a 2-point correlator of tensor currents and disagree with [2] on both OPE expansion and the value of QCD vacuum tensor susceptibility. Using our value for the latter we determine new estimations of nucleon tensor charges related to the first moment of the transverse structure functions h 1 of a nucleon
Structure functions and correlations in nuclei
Fantoni, S.
1988-01-01
In this paper the results obtained for the static structure function S(k) and the longitudinal structure function S L (k) of 3 H, 3 He and 4 He nuclei and nuclear matter are presented and discussed. The calculations have been performed using realistic wave functions obtained from Faddeev and variational theories. The Monte Carlo method has been used to calculate the structure functions of finite systems, and the FHNC/SOC method for nuclear matter. The results for the 3 He nucleus are in agreement with the recent Saclay data. The results for nuclear matter are compared with the experimental data relative to heavier nuclei, like e.g. 40 Ca
Renormalization group analysis of B →π form factors with B -meson light-cone sum rules
Shen, Yue-Long; Wei, Yan-Bing; Lü, Cai-Dian
2018-03-01
Within the framework of the B -meson light-cone sum rules, we review the calculation of radiative corrections to the three B →π transition form factors at leading power in Λ /mb. To resum large logarithmic terms, we perform the complete renormalization group evolution of the correlation function. We employ the integral transformation which diagonalizes evolution equations of the jet function and the B -meson light-cone distribution amplitude to solve these evolution equations and obtain renormalization group improved sum rules for the B →π form factors. Results of the form factors are extrapolated to the whole physical q2 region and are compared with that of other approaches. The effect of B -meson three-particle light-cone distribution amplitudes, which will contribute to the form factors at next-to-leading power in Λ /mb at tree level, is not considered in this paper.
The role of triplet correlation function in dense fluids
Rashid, R.I.M.A.
1993-09-01
In the theory of dense liquids, one usually introduces various correlation functions for describing properties of such systems. It has proved impossible to solve these correlation functions exactly and as such one often resorts to some meaningful approximations for their solutions. It is well known that unless proper precautions are taken, the approximate solutions will violate some useful sum rules and thermodynamic consistency conditions. Here the general rules for generating thermodynamically consistent approximate correlation functions are discussed. The role of triplet correlation is elucidated further by calculating a residual correction to the vacancy formation energy via three-particle correlation in rare gas solids. (author). 16 refs, 4 figs, 1 tab
Two-point correlation functions in inhomogeneous and anisotropic cosmologies
Marcori, Oton H.; Pereira, Thiago S.
2017-01-01
Two-point correlation functions are ubiquitous tools of modern cosmology, appearing in disparate topics ranging from cosmological inflation to late-time astrophysics. When the background spacetime is maximally symmetric, invariance arguments can be used to fix the functional dependence of this function as the invariant distance between any two points. In this paper we introduce a novel formalism which fixes this functional dependence directly from the isometries of the background metric, thus allowing one to quickly assess the overall features of Gaussian correlators without resorting to the full machinery of perturbation theory. As an application we construct the CMB temperature correlation function in one inhomogeneous (namely, an off-center LTB model) and two spatially flat and anisotropic (Bianchi) universes, and derive their covariance matrices in the limit of almost Friedmannian symmetry. We show how the method can be extended to arbitrary N -point correlation functions and illustrate its use by constructing three-point correlation functions in some simple geometries.
Two-point correlation functions in inhomogeneous and anisotropic cosmologies
Marcori, Oton H.; Pereira, Thiago S., E-mail: otonhm@hotmail.com, E-mail: tspereira@uel.br [Departamento de Física, Universidade Estadual de Londrina, 86057-970, Londrina PR (Brazil)
2017-02-01
Two-point correlation functions are ubiquitous tools of modern cosmology, appearing in disparate topics ranging from cosmological inflation to late-time astrophysics. When the background spacetime is maximally symmetric, invariance arguments can be used to fix the functional dependence of this function as the invariant distance between any two points. In this paper we introduce a novel formalism which fixes this functional dependence directly from the isometries of the background metric, thus allowing one to quickly assess the overall features of Gaussian correlators without resorting to the full machinery of perturbation theory. As an application we construct the CMB temperature correlation function in one inhomogeneous (namely, an off-center LTB model) and two spatially flat and anisotropic (Bianchi) universes, and derive their covariance matrices in the limit of almost Friedmannian symmetry. We show how the method can be extended to arbitrary N -point correlation functions and illustrate its use by constructing three-point correlation functions in some simple geometries.
Nucleon-nucleon momentum correlation function for light nuclei
Ma, Y.G.; Cai, X.Z.; Chen, J.G.; Fang, D.Q.; Guo, W.; Liu, G.H.; Ma, C.W.; Ma, E.J.; Shen, W.Q.; Shi, Y.; Su, Q.M.; Tian, W.D.; Wang, H.W.; Wang, K.; Wei, Y.B.; Yan, T.Z.
2007-01-01
Nucleon-nucleon momentum correlation function have been presented for nuclear reactions with neutron-rich or proton-rich projectiles using a nuclear transport theory, namely Isospin-Dependent Quantum Molecular Dynamics model. The relationship between the binding energy of projectiles and the strength of proton-neutron correlation function at small relative momentum has been explored, while proton-proton correlation function shows its sensitivity to the proton density distribution. Those results show that nucleon-nucleon correlation function is useful to reflect some features of the neutron- or proton-halo nuclei and therefore provide a potential tool for the studies of radioactive beam physics
Neurobiological correlates of social functioning in autism.
Neuhaus, Emily; Beauchaine, Theodore P; Bernier, Raphael
2010-08-01
Although autism is defined by deficits in three areas of functioning (social, communicative, and behavioral), impairments in social interest and restricted behavioral repertoires are central to the disorder. As a result, a detailed understanding of the neurobiological systems subserving social behavior may have implications for prevention, early identification, and intervention for affected families. In this paper, we review a number of potential neurobiological mechanisms--across several levels of analysis--that subserve normative social functioning. These include neural networks, neurotransmitters, and hormone systems. After describing the typical functioning of each system, we review available empirical findings specific to autism. Among the most promising potential mechanisms of social behavioral deficits in autism are those involving neural networks including the amygdala, the mesocorticolimbic dopamine system, and the oxytocin system. Particularly compelling are explanatory models that integrate mechanisms across biological systems, such as those linking dopamine and oxytocin with brain regions critical to reward processing. Copyright 2010 Elsevier Ltd. All rights reserved.
A test of conformal invariance: Correlation functions on a disk
Badke, R.; Rittenberg, V.; Ruegg, H.
1985-06-01
Using conformal invariance one can derive the correlation functions of a disk from those in the half-plane. The correlation function in the half-plane is determined by the 'small' conformal invariance up to an unknown function of one variable. By measuring through the Monte Carlo method the correlation function for two different configurations, the unknown function can be eliminated and one obtains a test of conformal invariance. It is shown that the Ising and the three state Potts model pass the test for very small lattices. (orig.)
Correlates of impaired function in older women.
Ensrud, K E; Nevitt, M C; Yunis, C; Cauley, J A; Seeley, D G; Fox, K M; Cummings, S R
1994-05-01
To determine the factors associated with impaired function in older women. Cross-sectional analysis of baseline data collected for a multicenter, prospective study of risk factors for osteoporotic fractures. Four clinical centers in Portland, Oregon, Minneapolis, Minnesota, Baltimore, Maryland, and the Monongahela Valley, Pennsylvania. A total of 9,704 ambulatory, non-black women, aged 65 years and older, recruited from population-based listings. Independent variables, including demographic and historical information (medical conditions, health habits, and medications) and physiologic measures (anthropometry, blood pressure, mental status, vision, and neuromuscular performance) were obtained from a baseline questionnaire, interview, and examination. Measurement of function was assessed by self-reported ability to perform six physical and instrumental activities of daily living (ADL) and impaired function (dependent variable) was defined as difficulty performing three or more physical and instrumental ADLs. In order of decreasing strength of association, hip fracture, osteoarthritis, parkinsonism, slower walking speed, lower hip abduction force, back pain, greater Quetelet index, osteoporosis, former alcohol use, stroke, never drinking alcohol, lower mental status, use of anxiolytics and/or sleeping medications, inability to hold the tandem position, postural dizziness, cataracts, greater waist to hip ratio, lower physical activity in the past year, greater lifetime cigarette consumption, and lower grip strength were independently associated with impaired function in multivariate analyses. Age, low educational level, diabetes, current heavy alcohol use, postural hypotension, depth perception, and contrast sensitivity were not independent predictors. A combination of neuromuscular performance measures, including decreased muscle strength and impaired balance and gait, appeared to account for the effect of age on disability. A combination of many factors, including
Meson effective mass in the isospin medium in hard-wall AdS/QCD model
Mamedov, Shahin [Gazi University, Department of Physics, Ankara (Turkey); Baku State University, Institute for Physical Problems, Baku (Azerbaijan); Azerbaijan National Academy of Sciences, Institute of Physics, Baku (Azerbaijan)
2016-02-15
We study a mass splitting of the light vector, axial-vector, and pseudoscalar mesons in the isospin medium in the framework of the hard-wall model. We write an effective mass definition for the interacting gauge fields and scalar field introduced in gauge field theory in the bulk of AdS space-time. Relying on holographic duality we obtain a formula for the effective mass of a boundary meson in terms of derivative operator over the extra bulk coordinate. The effective mass found in this way coincides with the one obtained from finding of poles of the two-point correlation function. In order to avoid introducing distinguished infrared boundaries in the quantization formula for the different mesons from the same isotriplet we introduce extra action terms at this boundary, which reduces distinguished values of this boundary to the same value. Profile function solutions and effective mass expressions were found for the in-medium ρ, a{sub 1}, an π mesons. (orig.)
On the application of correlation function matrices in OMA
Brincker, Rune
2017-01-01
In this paper the theoretical solution for the correlation function matrix of the random response of a structural system is re-visited. It is shown that using the classical definition of the correlation functions, the row space is defined by the mode shapes of the system, whereas the column space...
Correlation function of gravitational deflection angles of light paths
Watanabe, Kazuya; Tomita, Kenji.
1990-04-01
The correlation function of gravitational deflection angles of light paths is investigated in a simplified cosmological model universe. Under several reasonable assumptions, an analytic formula for the correlation function is derived. The implication to the cosmic microwave background anisotropy and the distance defined by the observed angular (linear) scale of a source is also discussed. (author)
Burden, C.J.
1998-01-01
Full text: Evidence for a meson with exotic quantum numbers J PC 1 -+ , the ρ(1405), has been observed at the AGS at Brookhaven and Crystal Barrel at CERN. This meson is exotic to the extent that its quantum numbers are not consistent with the generalised Pauli exclusion principle applied to the naive constituent quark model. In a fully relativistic field theoretic treatment, however, there is nothing in principle to preclude the existence of charge parity exotics. Using our earlier covariant Bethe-Salpeter model of light-quark mesons with no new parameter fitting we demonstrate the existence of a q - q-bar bound state with the quantum numbers of the ρ
Cumulant approach to dynamical correlation functions at finite temperatures
Tran Minhtien.
1993-11-01
A new theoretical approach, based on the introduction of cumulants, to calculate thermodynamic averages and dynamical correlation functions at finite temperatures is developed. The method is formulated in Liouville instead of Hilbert space and can be applied to operators which do not require to satisfy fermion or boson commutation relations. The application of the partitioning and projection methods for the dynamical correlation functions is discussed. The present method can be applied to weakly as well as to strongly correlated systems. (author). 9 refs
Correlation functions in first-order phase transitions
Garrido, V.; Crespo, D.
1997-09-01
Most of the physical properties of systems underlying first-order phase transitions can be obtained from the spatial correlation functions. In this paper, we obtain expressions that allow us to calculate all the correlation functions from the droplet size distribution. Nucleation and growth kinetics is considered, and exact solutions are obtained for the case of isotropic growth by using self-similarity properties. The calculation is performed by using the particle size distribution obtained by a recently developed model (populational Kolmogorov-Johnson-Mehl-Avrami model). Since this model is less restrictive than that used in previously existing theories, the result is that the correlation functions can be obtained for any dependence of the kinetic parameters. The validity of the method is tested by comparison with the exact correlation functions, which had been obtained in the available cases by the time-cone method. Finally, the correlation functions corresponding to the microstructure developed in partitioning transformations are obtained.
Correlation function behavior in quantum systems which are classically chaotic
Berman, G.P.; Kolovsky, A.R.
1983-01-01
The time behavior of a phase correlation function for dynamical quantum systems which are classically chaotic is considered. It is shown that under certain conditions there are three time regions of the quantum correlations behavior; the region of classical stochasticity (exponential decay of quantum correlations); the region of the correlations decay with a power law; the region of the constant level of the quantum correlations. The boundaries of these time regions are presented. The estimation of a remaining level of the quantum correlations is given. (orig.)
Asymptotics of Heavy-Meson Form Factors
Grozin, A.G.; Grozin, Andrey G.; Neubert, Matthias
1997-01-01
Using methods developed for hard exclusive QCD processes, we calculate the asymptotic behaviour of heavy-meson form factors at large recoil. It is determined by the leading- and subleading-twist meson wave functions. For $1\\ll |v\\cdot v'|\\ll m_Q/\\Lambda$, the form factors are dominated by the Isgur--Wise function, which is determined by the interference between the wave functions of leading and subleading twist. At $|v\\cdot v'|\\gg m_Q/\\Lambda$, they are dominated by two functions arising at order $1/m_Q$ in the heavy-quark expansion, which are determined by the leading-twist wave function alone. The sum of these contributions describes the form factors in the whole region $|v\\cdot v'|\\gg 1$. As a consequence, there is an exact zero in the form factor for the scattering of longitudinally polarized $B^*$ mesons at some value $v\\cdot v'\\sim m_b/\\Lambda$, and an approximate zero in the form factor of $B$ mesons in the timelike region ($v\\cdot v'\\sim -m_b/\\Lambda$). We obtain the evolution equations and sum rules ...
Semileptonic decays of the Bc meson
Barik, N.; Naimuddin, Sk.; Dash, P. C.; Kar, Susmita
2009-01-01
We study the semileptonic transitions B c →η c ,J/Ψ,D,D*,B,B*,B s ,B s * in the leading order in the framework of a relativistic independent quark model based on a confining potential in the equally mixed scalar-vector harmonic form. We compute relevant weak form factors as overlap integrals of the meson-wave functions obtained in the relativistic independent quark model in the whole accessible kinematical range. We predict that the semileptonic transitions of the B c meson are mostly dominated by two Cabibbo-Kobayashi-Maskawa (CKM)-favored modes, B c →B s (B s *)eν, contributing about 77% of the total decay width, and its decays to vector meson final states take place in the predominantly transverse mode. Our predicted values for the total decay rates, branching ratios, polarization ratios, the forward-backward asymmetry factor, etc., are broadly in agreement with other model predictions.
Perturbative QCD effects in heavy meson decays
Szezepaniak, A.; Henley, E.M.
1991-01-01
The amplitude for the exclusive nonleptonic decay of a heavy meson into two light pseudoscalar mesons is analyzed using the factorization formalism of perturbative QCD for exclusive reactions at large momentum transfer. We calculate the form factor b → u transition and compare it to the old quark model calculation and the new one based on the light cone formulation of the full quark model wave function. The new results we obtain are smaller by a factor of 2 - 3 as compared to the old value. (orig.)
Pennington, M.R.
1989-01-01
The search for I = 0 0 ++ mesons is described. The crucial role played by the states in the 1 GeV region is highlighted. An analysis program that with unimpeachable data would produce definitive results on these is outlined and shown with present data to provide prima facie evidence for dynamics beyond that of the quark model. The authors briefly speculate on the current status of the lowest mass scalar mesons and discuss how experiment can resolve the unanswered issues. 30 references, 6 figures, 1 table
Holographic correlation functions in Critical Gravity
Anastasiou, Giorgos; Olea, Rodrigo
2017-11-01
We compute the holographic stress tensor and the logarithmic energy-momentum tensor of Einstein-Weyl gravity at the critical point. This computation is carried out performing a holographic expansion in a bulk action supplemented by the Gauss-Bonnet term with a fixed coupling. The renormalization scheme defined by the addition of this topological term has the remarkable feature that all Einstein modes are identically cancelled both from the action and its variation. Thus, what remains comes from a nonvanishing Bach tensor, which accounts for non-Einstein modes associated to logarithmic terms which appear in the expansion of the metric. In particular, we compute the holographic 1-point functions for a generic boundary geometric source.
Quantum chromodynamics with infinite number of vector mesons
Geshkenbejn, B.V.
1988-01-01
Families of vector mesons Ρ,Ψ,Υ, contain an infinite number of resonances with gradually increasing widths are considered. The asymptotic freedom requirement involves a relationship between the electric width of k-th resonance and its mass M k derivative over the number k. It is shown that for the families of Ψ and Υ mesons the moment from experimental function R(s) is equal to the sum of the moment from a bare quark loop and the edge term which stems from replacing of summation by integration. These equalities are fulfilled up to 1% for 60 moments in the Ψ-meson family and up to 2% for 96 moments in the Υ-meson family. The electronic widths of the resonances and the Ρ-meson mass are calculated. 7 refs
Measurement of elastic electroproduction of $\\phi$ mesons at HERA
Adloff, C.; Andrieu, B.; Arkadov, V.; Astvatsatourov, A.; Ayyaz, I.; Babaev, A.; Bahr, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bassler, U.; Bate, P.; Beglarian, A.; Behnke, O.; Beier, C.; Belousov, A.; Benisch, T.; Berger, Christoph; Bernardi, G.; Berndt, T.; Bizot, J.C.; Borras, K.; Boudry, V.; Braunschweig, W.; Brisson, V.; Broker, H.B.; Brown, D.P.; Bruckner, W.; Bruel, P.; Bruncko, D.; Burger, J.; Busser, F.W.; Bunyatyan, A.; Burkhardt, H.; Burrage, A.; Buschhorn, G.; Campbell, A.J.; Cao, Jun; Carli, T.; Caron, S.; Chabert, E.; Clarke, D.; Clerbaux, B.; Collard, C.; Contreras, J.G.; Coughlan, J.A.; Cousinou, M.C.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; David, M.; Davidsson, M.; Delcourt, B.; Delerue, N.; Demirchyan, R.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dixon, P.; Dodonov, V.; Dowell, J.D.; Droutskoi, A.; Duprel, C.; Eckerlin, Guenter; Eckstein, D.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellerbrock, M.; Elsen, E.; Erdmann, M.; Erdmann, W.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Ferron, S.; Fleischer, M.; Flugge, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Foster, J.M.; Franke, G.; Gabathuler, E.; Gabathuler, K.; Garvey, J.; Gassner, J.; Gayler, Joerg; Gerhards, R.; Ghazarian, S.; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goodwin, C.; Grab, C.; Grassler, H.; Greenshaw, T.; Grindhammer, Guenter; Hadig, T.; Haidt, D.; Hajduk, L.; Haynes, W.J.; Heinemann, B.; Heinzelmann, G.; Henderson, R.C.W.; Hengstmann, S.; Henschel, H.; Heremans, R.; Herrera, G.; Herynek, I.; Hilgers, M.; Hiller, K.H.; Hladky, J.; Hoting, P.; Hoffmann, D.; Hoprich, W.; Horisberger, R.; Hurling, S.; Ibbotson, M.; Issever, C.; Jacquet, M.; Jaffre, M.; Janauschek, L.; Jansen, D.M.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jones, M.A.S.; Jung, H.; Kastli, H.K.; Kant, D.; Kapichine, M.; Karlsson, M.; Karschnick, O.; Kaufmann, O.; Kausch, M.; Keil, F.; Keller, N.; Kennedy, J.; Kenyon, I.R.; Kermiche, S.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Knies, G.; Koblitz, B.; Kolya, S.D.; Korbel, V.; Kostka, P.; Kotelnikov, S.K.; Krasny, M.W.; Krehbiel, H.; Kroseberg, J.; Krucker, D.; Kruger, K.; Kupper, A.; Kuhr, T.; Kurca, T.; Kutuev, R.; Lachnit, W.; Lahmann, R.; Lamb, D.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Lebedev, A.; Leissner, B.; Lemrani, R.; Lendermann, V.; Levonian, S.; Lindstrom, M.; Lobodzinska, E.; Lobodzinski, B.; Loktionova, N.; Lubimov, V.; Luders, S.; Luke, D.; Lytkin, L.; Magnussen, N.; Mahlke-Kruger, H.; Malden, N.; Malinovski, E.; Malinovski, I.; Maracek, R.; Marage, P.; Marks, J.; Marshall, R.; Martyn, H.U.; Martyniak, J.; Maxfield, S.J.; Mehta, A.; Meier, K.; Merkel, P.; Metlica, F.; Meyer, H.; Meyer, J.; Meyer, P.O.; Mikocki, S.; Milstead, D.; Mkrtchyan, T.; Mohr, R.; Mohrdieck, S.; Mondragon, M.N.; Moreau, F.; Morozov, A.; Morris, J.V.; Muller, K.; Murin, P.; Nagovizin, V.; Naroska, B.; Naumann, J.; Naumann, T.; Nellen, G.; Newman, Paul R.; Nicholls, T.C.; Niebergall, F.; Niebuhr, C.; Nix, O.; Nowak, G.; Nunnemann, T.; Olsson, J.E.; Ozerov, D.; Panassik, V.; Pascaud, C.; Patel, G.D.; Perez, E.; Phillips, J.P.; Pitzl, D.; Poschl, R.; Potachnikova, I.; Povh, B.; Rabbertz, K.; Radel, G.; Rauschenberger, J.; Reimer, P.; Reisert, B.; Reyna, D.; Riess, S.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Royon, C.; Rusakov, S.; Rybicki, K.; Sankey, D.P.C.; Scheins, J.; Schilling, F.P.; Schleper, P.; Schmidt, D.; Schoeffel, L.; Schoning, A.; Schorner, T.; Schroder, V.; Schultz-Coulon, H.C.; Sedlak, K.; Sefkow, F.; Chekelian, V.I.; Sheviakov, I.; Shtarkov, L.N.; Siegmon, G.; Sievers, P.; Sirois, Y.; Sloan, T.; Smirnov, P.; Solochenko, V.; Solovev, Y.; Spaskov, V.; Specka, Arnd E.; Spitzer, H.; Stamen, R.; Steinhart, J.; Stella, B.; Stellberger, A.; Stiewe, J.; Straumann, U.; Struczinski, W.; Swart, M.; Tasevsky, M.; Tchernyshov, V.; Tchetchelnitski, S.; Thompson, Graham; Thompson, P.D.; Tobien, N.; Traynor, D.; Truoel, Peter; Tsipolitis, G.; Turnau, J.; Turney, J.E.; Tzamariudaki, E.; Udluft, S.; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vazdik, Y.; von Dombrowski, S.; Wacker, K.; Wallny, R.; Walter, T.; Waugh, B.; Weber, G.; Weber, M.; Wegener, D.; Wegner, A.; Wengler, T.; Werner, M.; White, G.; Wiesand, S.; Wilksen, T.; Winde, M.; Winter, G.G.; Wissing, C.; Wobisch, M.; Wollatz, H.; Wunsch, E.; Wyatt, A.C.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zomer, F.; Zsembery, J.
2000-01-01
The elastic electroproduction of phi mesons is studied at HERA with the H1 detector for photon virtualities 1 < Q^2 < 15 GeV^2 and hadronic centre of mass energies 40 < W < 130 GeV. The Q^2 and t dependences of the cross section are extracted (t being the square of the four-momentum transfer to the target proton). When plotted as function of (Q^2 + M_V^2) and scaled by the appropriate SU(5) quark charge factor, the phi meson cross section agrees within errors with the cross sections of the vector mesons V = rho, omega and J/psi. A detailed analysis is performed of the phi meson polarisation state and the ratio of the production cross sections for longitudinally and transversely polarised phi mesons is determined. A small but significant violation of s-channel helicity conservation (SCHC) is observed.
Heavy meson observables and Dyson-Schwinger equations
Ivanov, M. A.
1998-01-01
Dyson-Schwinger equation (DSE) studies show that the b-quark mass-function is approximately constant, and that this is true to a lesser extent for the c-quark. This observation provides the basis for a study of the leptonic and semileptonic decays of heavy pseudoscalar mesons using a ''heavy-quark'' limit of the DSES, which, when exact, reduces the number of independent form factors. Semileptonic decays with light mesons in the final state are also accessible because the DSES provide a description of light-quark propagation characteristics and light-meson structure. A description of B-meson decays is straightforward, however, the study of decays involving the D-meson indicates that c-quark mass-corrections are quantitatively important
Correlation Functions in Open Quantum-Classical Systems
Hsieh, Chang-Yu; Kapral, Raymond
2013-01-01
Quantum time correlation functions are often the principal objects of interest in experimental investigations of the dynamics of quantum systems. For instance, transport properties, such as diffusion and reaction rate coefficients, can be obtained by integrating these functions. The evaluation of such correlation functions entails sampling from quantum equilibrium density operators and quantum time evolution of operators. For condensed phase and complex systems, where quantum dynamics is diff...
Psychological correlates of functional hypothalamic amenorrhea.
Marcus, M D; Loucks, T L; Berga, S L
2001-08-01
To determine whether mood, attitudes, or symptoms of disordered eating discriminated women with functional hypothalamic amenorrhea (FHA) from those with organic causes of amenorrhea and eumenorrhea. Cross-sectional comparison of women with FHA, women with organic amenorrhea, and eumenorrheic control women. Clinical research center in an academic medical institution. Seventy-seven women > or =18 years old with time since menarche > or =5 and < or =25 years were recruited by advertisement. Ovulation was confirmed in eumenorrheic control women. Causes of anovulation were carefully documented in amenorrheic participants and LH pulse profiles were obtained to document the diagnosis of FHA. All participants were interviewed and completed questionnaires. Self-report measures of dysfunctional attitudes, coping styles, and symptoms of depression and eating disorders. Women with FHA reported more depressive symptoms and dysfunctional attitudes than did eumenorrheic women, but not significantly more than women with organic amenorrhea. However, women with FHA reported significantly more symptoms of disordered eating than did either anovulatory or ovulatory women. The findings are consistent with the hypothesis that FHA is precipitated by a combination of psychosocial stressors and metabolic challenge.
42 CFR 476.86 - Correlation of Title XI functions with Title XVIII functions.
2010-10-01
... 42 Public Health 4 2010-10-01 2010-10-01 false Correlation of Title XI functions with Title XVIII functions. 476.86 Section 476.86 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF...) Qio Review Functions § 476.86 Correlation of Title XI functions with Title XVIII functions. (a...
Vector mesons in strongly interacting matter
E-mail: volker.metag@exp2.physik.uni-giessen.de. Abstract. .... constraints on hadronic spectral functions but cannot predict their detailed shape. Hadronic ..... nuclear medium, despite a cut on low momentum ω-mesons: pω ≤ 500 MeV/c. A.
Vector mesons in strongly interacting matter
Results on the light vector mesons ρ, , and , are summarized and compared. Almost all experiments report a softening of the spectral functions with increases in width depending on the density and temperature of the hadronic environment. No evidence for mass shifts is found in majority of the experiments. Remaining ...
PROPERTIES OF THE $omega$ MESON
Shafer, J. B.; Murray, J. J.; Ferro-Luzzi, M.; Huwe, D. O.
1963-06-15
Properties of the omega meson were studied from the reaction K/sup -/ + p yields LAMBDA + omega in a 72-in. hydrogen bubble chamber. The momentum of the K/sup -/ mesons was 1.2 to 1.75 Bev/c. The mass of the omega meson is found to be 782 Mev with a width, predominated by three-meson( pi ) decay mode, estimated to be less than 4 Mev. Branching ratios for omega -meson decay into pi /sup +/ pi /sup -/ pi /sup o/, pi /sup o/ gamma , pi /sup +/ i/ sup -/, and e/sup +/e/sup -o/ were determined. (R.E.U.)
Understanding volatility correlation behavior with a magnitude cross-correlation function
Jun, Woo Cheol; Oh, Gabjin; Kim, Seunghwan
2006-06-01
We propose an approach for analyzing the basic relation between correlation properties of the original signal and its magnitude fluctuations by decomposing the original signal into its positive and negative fluctuation components. We use this relation to understand the following phenomenon found in many naturally occurring time series: the magnitude of the signal exhibits long-range correlation, whereas the original signal is short-range correlated. The applications of our approach to heart rate variability signals and high-frequency foreign exchange rates reveal that the difference between the correlation properties of the original signal and its magnitude fluctuations is induced by the time organization structure of the correlation function between the magnitude fluctuations of positive and negative components. We show that this correlation function can be described well by a stretched-exponential function and is related to the nonlinearity and the multifractal structure of the signals.
Understanding volatility correlation behavior with a magnitude cross-correlation function.
Jun, Woo Cheol; Oh, Gabjin; Kim, Seunghwan
2006-06-01
We propose an approach for analyzing the basic relation between correlation properties of the original signal and its magnitude fluctuations by decomposing the original signal into its positive and negative fluctuation components. We use this relation to understand the following phenomenon found in many naturally occurring time series: the magnitude of the signal exhibits long-range correlation, whereas the original signal is short-range correlated. The applications of our approach to heart rate variability signals and high-frequency foreign exchange rates reveal that the difference between the correlation properties of the original signal and its magnitude fluctuations is induced by the time organization structure of the correlation function between the magnitude fluctuations of positive and negative components. We show that this correlation function can be described well by a stretched-exponential function and is related to the nonlinearity and the multifractal structure of the signals.
Self-calibrated correlation imaging with k-space variant correlation functions.
Li, Yu; Edalati, Masoud; Du, Xingfu; Wang, Hui; Cao, Jie J
2018-03-01
Correlation imaging is a previously developed high-speed MRI framework that converts parallel imaging reconstruction into the estimate of correlation functions. The presented work aims to demonstrate this framework can provide a speed gain over parallel imaging by estimating k-space variant correlation functions. Because of Fourier encoding with gradients, outer k-space data contain higher spatial-frequency image components arising primarily from tissue boundaries. As a result of tissue-boundary sparsity in the human anatomy, neighboring k-space data correlation varies from the central to the outer k-space. By estimating k-space variant correlation functions with an iterative self-calibration method, correlation imaging can benefit from neighboring k-space data correlation associated with both coil sensitivity encoding and tissue-boundary sparsity, thereby providing a speed gain over parallel imaging that relies only on coil sensitivity encoding. This new approach is investigated in brain imaging and free-breathing neonatal cardiac imaging. Correlation imaging performs better than existing parallel imaging techniques in simulated brain imaging acceleration experiments. The higher speed enables real-time data acquisition for neonatal cardiac imaging in which physiological motion is fast and non-periodic. With k-space variant correlation functions, correlation imaging gives a higher speed than parallel imaging and offers the potential to image physiological motion in real-time. Magn Reson Med 79:1483-1494, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.
A search for non-$q\\overline{q}$ mesons in the WA102 experiment at the CERN Omega Spectrometer
Kirk, A
1998-01-01
A study of central meson production as a function of the difference in transverse momentum dPT of the exchanged particles shows that undisputed qqbar mesons are suppressed at small dPT whereas the glueball candidates are enhanced.
Vento, Vicente [Consejo Superior de Investigaciones Cientificas, Departamento de Fisica Teorica y Instituto de Fisica Corpuscular, Universidad de Valencia, Burjassot (Spain)
2016-01-15
Calculations in unquenched QCD for the scalar glueball spectrum have confirmed previous results of Gluodynamics finding a glueball at ∝1750 MeV. I analyze the implications of this discovery from the point of view of glueball-meson mixing in light of the experimental scalar spectrum. (orig.)
Frederic D. R. Bonnet; Robert G. Edwards; George T. Fleming; Randal Lewis; David Richards
2003-07-22
We have started a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present preliminary results computed with domain wall valence fermions on MILC asqtad lattices, as well as Wilson fermions on quenched lattices. These methods can easily be extended to rho-to-gamma-pi transition form factors.
Techniques in meson spectroscopy
Longacre, R.S.
1991-01-01
This report contains lectures on the following topics: the quark model and beyond using quantum chromodynamics; analysis of formation reactions; energy dependence of the partial wave amplitudes; where the data for the t-matrix analysis comes from; and coupled channel analysis of isoscalar mesons
Tetraquark and two-meson states at large N{sub c}
Lucha, Wolfgang [Austrian Academy of Sciences, Institute for High Energy Physics, Vienna (Austria); Melikhov, Dmitri [Austrian Academy of Sciences, Institute for High Energy Physics, Vienna (Austria); M.V. Lomonosov Moscow State University, D.V. Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); University of Vienna, Faculty of Physics, Vienna (Austria); Sazdjian, Hagop [IPNO, Universite Paris-Sud, CNRS-IN2P3, Universite Paris-Saclay, Orsay (France)
2017-12-15
Considering four-point correlation functions of color-singlet quark bilinears, we investigate, in the large-N{sub c} limit of QCD, the subleading diagrams that involve, in the s-channel of meson-meson scattering amplitudes, two-quark-two-antiquark intermediate states. The latter contribute, together with gluon exchanges, to the formation, at the hadronic level, of two-meson and tetraquark intermediate states. It is shown that the two-meson contributions, which are predictable, in general, from leading-order N{sub c}-behaviors, consistently satisfy the constraints resulting from the 1/N{sub c} expansion procedure and thus provide a firm basis for the extraction of tetraquark properties from N{sub c}-subleading diagrams. We find that, in general, tetraquarks, if they exist in compact form, should have narrow decay widths, of the order of N{sub c}{sup -2}. For the particular case of exotic tetraquarks, involving four different quark flavors, two different types of tetraquark are needed, each having a preferred decay channel, to satisfy the consistency constraints. (orig.)
Rotational Invariance of the 2d Spin - Spin Correlation Function
Pinson, Haru
2012-09-01
At the critical temperature in the 2d Ising model on the square lattice, we establish the rotational invariance of the spin-spin correlation function using the asymptotics of the spin-spin correlation function along special directions (McCoy and Wu in the two dimensional Ising model. Harvard University Press, Cambridge, 1973) and the finite difference Hirota equation for which the spin-spin correlation function is shown to satisfy (Perk in Phys Lett A 79:3-5, 1980; Perk in Proceedings of III international symposium on selected topics in statistical mechanics, Dubna, August 22-26, 1984, JINR, vol II, pp 138-151, 1985).
Lifetime information from correlation functions selected by directional cuts
Gelbke, C.K.
1995-01-01
Two-particle correlation functions provide information on the space-time characteristics of the emitting source. In many cases, ambiguities of the relative magnitudes of source radius and lifetime can be reduced by analysis of correlation functions evaluated for specific directional cuts on the relative velocity of the coincident particle pair. Information on non-spherical breakup geometries is more difficult to extract. Examples of two-proton correlation functions in which directional cuts are employed to reduce existing space-time ambiguities for the emitting system are presented. (author). 50 refs., 10 figs
Strong Correlation in Kohn-Sham Density Functional Theory
Malet, F.; Gori Giorgi, P.
2012-01-01
We use the exact strong-interaction limit of the Hohenberg-Kohn energy density functional to approximate the exchange-correlation energy of the restricted Kohn-Sham scheme. Our approximation corresponds to a highly nonlocal density functional whose functional derivative can be easily constructed,
Vector mesons in meson-baryon scattering and large-N{sub c} quantum chromodynamics
Fuhrmann, Hans-Friedrich
2016-02-11
We examined strong interactions in the low-energy regime in terms of two complementary non-perturbative approaches: the interplay of large-N{sub c} QCD and chiral perturbation theory was studied. While the expansion in the parameter 1/N{sub c} is based on quark and gluon degrees of freedom, chiral perturbation theory uses hadrons as effective degrees of freedom. The focus of our work was the investigation of mesons and baryons composed from up-, down- and strange quarks. We used the chiral SU(3) Lagrangian with (J{sup P}=(1)/(2){sup +})- and (J{sup P}=(3)/(2){sup +})-baryon ground states as building blocks. In the SU(3)-flavour limit the latter form an octet and a decuplet, respectively. Studies in chiral perturbation theory hold a challenge: the chiral Lagrangian consists of an infinite number of terms. The treatment of low-energy QCD physics via a perturbation theory requires the ordering of these terms according to their relevance. We used the interplay between large-N{sub c} QCD and chiral perturbation theory to shed light on the structure of the chiral Lagrangian. In the limit of large-N{sub c} the low-energy parameters of the chiral Lagrangian are correlated. For instance the masses of the two baryon multiplets turn degenerate in the SU(3)-flavour limit. This serves as the starting point of our investigations. In this work we analysed the time-ordered product of two scalar and two vector currents in the baryon ground state. The examination of these matrix elements at large-N{sub c} was compared to corresponding results derived in chiral perturbation theory. From this we obtained sum rules for some low-energy parameters of the chiral Lagrangian. The results for the vector correlation function were used to constrain a phenomenological interaction of light vector mesons with the baryon ground states. In the second part of this thesis we addressed a formal problem which arises in a partial wave decomposition of reaction amplitudes for particles with non
Vector mesons in meson-baryon scattering and large-N_c quantum chromodynamics
Fuhrmann, Hans-Friedrich
2016-01-01
We examined strong interactions in the low-energy regime in terms of two complementary non-perturbative approaches: the interplay of large-N_c QCD and chiral perturbation theory was studied. While the expansion in the parameter 1/N_c is based on quark and gluon degrees of freedom, chiral perturbation theory uses hadrons as effective degrees of freedom. The focus of our work was the investigation of mesons and baryons composed from up-, down- and strange quarks. We used the chiral SU(3) Lagrangian with (J"P=(1)/(2)"+)- and (J"P=(3)/(2)"+)-baryon ground states as building blocks. In the SU(3)-flavour limit the latter form an octet and a decuplet, respectively. Studies in chiral perturbation theory hold a challenge: the chiral Lagrangian consists of an infinite number of terms. The treatment of low-energy QCD physics via a perturbation theory requires the ordering of these terms according to their relevance. We used the interplay between large-N_c QCD and chiral perturbation theory to shed light on the structure of the chiral Lagrangian. In the limit of large-N_c the low-energy parameters of the chiral Lagrangian are correlated. For instance the masses of the two baryon multiplets turn degenerate in the SU(3)-flavour limit. This serves as the starting point of our investigations. In this work we analysed the time-ordered product of two scalar and two vector currents in the baryon ground state. The examination of these matrix elements at large-N_c was compared to corresponding results derived in chiral perturbation theory. From this we obtained sum rules for some low-energy parameters of the chiral Lagrangian. The results for the vector correlation function were used to constrain a phenomenological interaction of light vector mesons with the baryon ground states. In the second part of this thesis we addressed a formal problem which arises in a partial wave decomposition of reaction amplitudes for particles with non-vanishing spin. In particular we considered the vector
A calculation of the physical mass of sigma meson
Morones-Ibarra, J.R.; Santos-Guevara, Ayax
2007-01-01
We calculate the physical mass and the width of the sigma meson by considering that it couples in vacuum to two virtual pions. The mass is calculated by using the spectral function, and we find that it is about 600 MeV. In addition, we obtained 220 MeV as the value for the width of its spectral function. The value obtained for the mass is in good agreement with that reported in the Particle Data Book for the σ meson, which is also named f 0 (600). This result also shows that σ-meson can be considered as a two-pion resonance. (author)
Electroproduction of pseudoscalar mesons at large transverse momenta
Domokos, G.; Kovesi-Domokos, S.; Yunn, B. C.
1973-07-15
Inclusive electroproduction of spinless (pseudoscalar) mesons at large transverse momenta is studied in the framework of local scale invariance. Scaling laws are established for the structure iunctions and approximate analytic expressions are derived for the scaling functions. It is predicted that the cross section decreases essentially according to a power law as a function of the transverse momentum of the observed meson, similarly to hadronic cross sections. The production rate of heavy mesons is found to rise slowly with the laboratory energy of the virtual photon. (auth)
de Araújo, W. R. B.; de Melo, J. P. B. C.; Tsushima, K.
2018-02-01
We study the nucleon electromagnetic (EM) form factors in symmetric nuclear matter as well as in vacuum within a light-front approach using the in-medium inputs calculated by the quark-meson coupling model. The same in-medium quark properties are used as those used for the study of in-medium pion properties. The zero of the proton EM form factor ratio in vacuum, the electric to magnetic form factor ratio μpGEp (Q2) /GMp (Q2) (Q2 = -q2 > 0 with q being the four-momentum transfer), is determined including the latest experimental data by implementing a hard constituent quark component in the nucleon wave function. A reasonable fit is achieved for the ratio μpGEp (Q2) /GMp (Q2) in vacuum, and we predict that the Q02 value to cross the zero of the ratio to be about 15 GeV2. In addition the double ratio data of the proton EM form factors in 4He and H nuclei, [GEp4He (Q2) /G4HeMp (Q2) ] / [GEp1H (Q2) /GMp1H (Q2) ], extracted by the polarized (e → ,e‧ p →) scattering experiment on 4He at JLab, are well described. We also predict that the Q02 value satisfying μpGEp (Q02) /GMp (Q0 2) = 0 in symmetric nuclear matter, shifts to a smaller value as increasing nuclear matter density, which reflects the facts that the faster falloff of GEp (Q2) as increasing Q2 and the increase of the proton mean-square charge radius. Furthermore, we calculate the neutron EM form factor double ratio in symmetric nuclear matter for 0.1 neutron double ratio is enhanced relative to that in vacuum, while for the proton it is quenched, and agrees with an existing theoretical prediction.
Universality of correlation functions in random matrix models of QCD
Jackson, A.D.; Sener, M.K.; Verbaarschot, J.J.M.
1997-01-01
We demonstrate the universality of the spectral correlation functions of a QCD inspired random matrix model that consists of a random part having the chiral structure of the QCD Dirac operator and a deterministic part which describes a schematic temperature dependence. We calculate the correlation functions analytically using the technique of Itzykson-Zuber integrals for arbitrary complex supermatrices. An alternative exact calculation for arbitrary matrix size is given for the special case of zero temperature, and we reproduce the well-known Laguerre kernel. At finite temperature, the microscopic limit of the correlation functions are calculated in the saddle-point approximation. The main result of this paper is that the microscopic universality of correlation functions is maintained even though unitary invariance is broken by the addition of a deterministic matrix to the ensemble. (orig.)
Correlation between cognitive function, gross motor skills and health â
Saly Said Abd El-Hady
... attention and concentration, learning, memory and language that can result in mild to profound ... adulthood and affect health related quality of life (HRQOL) and wellbeing in ... investigate the correlation between cognitive function; attention/-.
Search for rare B meson decays into D+s mesons
Albrecht, H.; Ehrlichmann, H.; Hamacher, T.
1993-04-01
A search has been performed for rare B meson decays into D s + mesons arising from b → u transitions, W exchange modes, B + annihilation processes, and decays where the D s + is not produced via a W → c anti s quark pair coupling, using the ARGUS detector operating on the Y(4S) resonance at the e + e - storage ring DORIS II. Upper limits for individual decay modes are obtained. In addition, from a study of D s + l - correlations an upper limit of BR(B → D s + l - X) < 1.2% (90% CL) is determined. (orig.)
Mcclelland, J.; Silk, J.
1979-01-01
The evolution of the two-point correlation function for the large-scale distribution of galaxies in an expanding universe is studied on the assumption that the perturbation densities lie in a Gaussian distribution centered on any given mass scale. The perturbations are evolved according to the Friedmann equation, and the correlation function for the resulting distribution of perturbations at the present epoch is calculated. It is found that: (1) the computed correlation function gives a satisfactory fit to the observed function in cosmological models with a density parameter (Omega) of approximately unity, provided that a certain free parameter is suitably adjusted; (2) the power-law slope in the nonlinear regime reflects the initial fluctuation spectrum, provided that the density profile of individual perturbations declines more rapidly than the -2.4 power of distance; and (3) both positive and negative contributions to the correlation function are predicted for cosmological models with Omega less than unity.
Correlation functions for Hermitian many-body systems: Necessary conditions
Brown, E.B.
1994-01-01
Lee [Phys. Rev. B 47, 8293 (1993)] has shown that the odd-numbered derivatives of the Kubo autocorrelation function vanish at t=0. We show that this condition is based on a more general property of nondiagonal Kubo correlation functions. This general property provides that certain functional forms (e.g., simple exponential decay) are not admissible for any symmetric or antisymmetric Kubo correlation function in a Hermitian many-body system. Lee's result emerges as a special case of this result. Applications to translationally invariant systems and systems with rotational symmetries are also demonstrated
Structural and functional cerebral correlates of hypnotic suggestibility.
Alexa Huber
Full Text Available Little is known about the neural bases of hypnotic suggestibility, a cognitive trait referring to the tendency to respond to hypnotic suggestions. In the present magnetic resonance imaging study, we performed regression analyses to assess hypnotic suggestibility-related differences in local gray matter volume, using voxel-based morphometry, and in waking resting state functional connectivity of 10 resting state networks, in 37 healthy women. Hypnotic suggestibility was positively correlated with gray matter volume in portions of the left superior and medial frontal gyri, roughly overlapping with the supplementary and pre-supplementary motor area, and negatively correlated with gray matter volume in the left superior temporal gyrus and insula. In the functional connectivity analysis, hypnotic suggestibility was positively correlated with functional connectivity between medial posterior areas, including bilateral posterior cingulate cortex and precuneus, and both the lateral visual network and the left fronto-parietal network; a positive correlation was also found with functional connectivity between the executive-control network and a right postcentral/parietal area. In contrast, hypnotic suggestibility was negatively correlated with functional connectivity between the right fronto-parietal network and the right lateral thalamus. These findings demonstrate for the first time a correlation between hypnotic suggestibility, the structural features of specific cortical regions, and the functional connectivity during the normal resting state of brain structures involved in imagery and self-monitoring activity.
Structural and functional cerebral correlates of hypnotic suggestibility.
Huber, Alexa; Lui, Fausta; Duzzi, Davide; Pagnoni, Giuseppe; Porro, Carlo Adolfo
2014-01-01
Little is known about the neural bases of hypnotic suggestibility, a cognitive trait referring to the tendency to respond to hypnotic suggestions. In the present magnetic resonance imaging study, we performed regression analyses to assess hypnotic suggestibility-related differences in local gray matter volume, using voxel-based morphometry, and in waking resting state functional connectivity of 10 resting state networks, in 37 healthy women. Hypnotic suggestibility was positively correlated with gray matter volume in portions of the left superior and medial frontal gyri, roughly overlapping with the supplementary and pre-supplementary motor area, and negatively correlated with gray matter volume in the left superior temporal gyrus and insula. In the functional connectivity analysis, hypnotic suggestibility was positively correlated with functional connectivity between medial posterior areas, including bilateral posterior cingulate cortex and precuneus, and both the lateral visual network and the left fronto-parietal network; a positive correlation was also found with functional connectivity between the executive-control network and a right postcentral/parietal area. In contrast, hypnotic suggestibility was negatively correlated with functional connectivity between the right fronto-parietal network and the right lateral thalamus. These findings demonstrate for the first time a correlation between hypnotic suggestibility, the structural features of specific cortical regions, and the functional connectivity during the normal resting state of brain structures involved in imagery and self-monitoring activity.
Asymmetries in heavy meson production from light quark fragmentation
Dias de Deus, J.; Duraes, F.
2000-01-01
We discuss the possibility of the asymmetry in D - /D + production from π - beams, being a direct consequence of the properties of the light quark fragmentation function into heavy mesons. The main features of the asymmetry, as a function of x F , are easily described. An integrated sum rule for the D - , D + multiplicity difference is presented. Predictions for the asymmetry in B meson production are given. (orig.)
Guellenstern, S.
1991-09-01
Using the technique of Cherniak and Zhitnitzky we have calculated the wavefunctions of ρ(770) and Φ(1020) within the framework of QCD sum rules. Whereas the standard approach assumes light-like distances of the quarks (z 2 = 0), we also have taken into account higher order terms in z 2 . Thus, we obtained non-vanishing orbital angular momentum contributions. The first few moments of various invariant functions have been calculated with the help of an especially developed REDUCE program package. In zeroth order (z 2 = 0) our results of the reconstructed wavefunctions agree with those in the literature. However, we got first order contributions in z 2 of an amount of almost 10% of the corresponding zeroth order. (orig.)
Discovery of omega meson, first neutral vector meson
Anon.
1976-01-01
A personal account of the discovery of the ω meson is given by researcher B. Maglich. His account includes such topics as early and unsuccessful searches for a neutral vector meson (by himself and others), eventual discovery of the rho meson, the Goldhaber effect, and the observation and characterization of the ω meson. Explanatory physics notes on electromagnetic structure experiments and the determination of the quantum numbers of the ω meson are provided for nonspecialists. Also included are an outline of the relation between vector mesons and nuclear forces, a reprint of the Physical Review Letter on Evidence for a T = 0 three-pion resonance, and a scientific autobiography of the researcher. 14 figures, 1 table
Efficient quantum algorithm for computing n-time correlation functions.
Pedernales, J S; Di Candia, R; Egusquiza, I L; Casanova, J; Solano, E
2014-07-11
We propose a method for computing n-time correlation functions of arbitrary spinorial, fermionic, and bosonic operators, consisting of an efficient quantum algorithm that encodes these correlations in an initially added ancillary qubit for probe and control tasks. For spinorial and fermionic systems, the reconstruction of arbitrary n-time correlation functions requires the measurement of two ancilla observables, while for bosonic variables time derivatives of the same observables are needed. Finally, we provide examples applicable to different quantum platforms in the frame of the linear response theory.
Liquid ammonia: Molecular correlation functions from x-ray diffraction
Narten, A.H.
1977-01-01
For nearly spherical molecules the x-ray scattering from liquids yields structure and correlation functions for molecular centers. The distribution of electron density in an ammonia molecular is very nearly spherical, and orientational correlation between molecules in the liquid is not ''seen'' by x rays. Structure and correlation functions for molecular centers (nitrogen atoms) are derived from x-ray data on liquid NH 3 at 4 degreeC and tabulated. They provide a sensitive test for future work on a molecular theory of liquid ammonia
Meson life time in the anisotropic quark-gluon plasma
Ali-Akbari, Mohammad; Allahbakhshi, Davood
2014-01-01
In the hot (an)isotropic plasma the meson life time τ is defined as a time scale after which the meson dissociates. According to the gauge/gravity duality, this time can be identified with the inverse of the imaginary part of the frequency of the quasinormal modes, ω_I, in the (an)isotropic black hole background. In the high temperature limit, we numerically show that at fixed temperature(entropy density) the life time of the mesons decreases(increases) as the anisotropy parameter raises. For general case, at fixed temperature we introduce a polynomial function for ω_I and observe that the meson life time decreases. Moreover, we realize that (s/T"3)"6, where s and T are entropy density and temperature of the plasma respectively, can be expressed as a function of anisotropy parameter over temperature. Interestingly, this function is a Padé approximant.
SU(4) flavor symmetry breaking in D-meson couplings to light hadrons
Fontoura, C.E. [Instituto Tecnologico da Aeronautica, DCTA, Sao Jose dos Campos, SP (Brazil); Universidade Estadual Paulista, Instituto de Fisica Teorica, Sao Paulo, SP (Brazil); Haidenbauer, J. [Institute for Advanced Simulation, Institut fuer Kernphysik, and Juelich Center for Hadron Physics, Forschungszentrum Juelich, Juelich (Germany); Krein, G. [Universidade Estadual Paulista, Instituto de Fisica Teorica, Sao Paulo, SP (Brazil)
2017-05-15
The validity of SU(4)-flavor symmetry relations of couplings of charmed D-mesons to light mesons and baryons is examined with the use of {sup 3}P{sub 0} quark-pair creation model and nonrelativistic quark-model wave functions. We focus on the three-meson couplings ππρ, KKρ and DDρ and baryon-baryon-meson couplings NNπ, NΛK and NΛ{sub c}D. It is found that SU(4)-flavor symmetry is broken at the level of 30% in the DDρ tree-meson couplings and 20% in the baryon-baryon-meson couplings. Consequences of these findings for DN cross sections and existence of bound states D-mesons in nuclei are discussed. (orig.)
Universal Spatial Correlation Functions for Describing and Reconstructing Soil Microstructure
Skvortsova, Elena B.; Mallants, Dirk
2015-01-01
Structural features of porous materials such as soil define the majority of its physical properties, including water infiltration and redistribution, multi-phase flow (e.g. simultaneous water/air flow, or gas exchange between biologically active soil root zone and atmosphere) and solute transport. To characterize soil microstructure, conventional soil science uses such metrics as pore size and pore-size distributions and thin section-derived morphological indicators. However, these descriptors provide only limited amount of information about the complex arrangement of soil structure and have limited capability to reconstruct structural features or predict physical properties. We introduce three different spatial correlation functions as a comprehensive tool to characterize soil microstructure: 1) two-point probability functions, 2) linear functions, and 3) two-point cluster functions. This novel approach was tested on thin-sections (2.21×2.21 cm2) representing eight soils with different pore space configurations. The two-point probability and linear correlation functions were subsequently used as a part of simulated annealing optimization procedures to reconstruct soil structure. Comparison of original and reconstructed images was based on morphological characteristics, cluster correlation functions, total number of pores and pore-size distribution. Results showed excellent agreement for soils with isolated pores, but relatively poor correspondence for soils exhibiting dual-porosity features (i.e. superposition of pores and micro-cracks). Insufficient information content in the correlation function sets used for reconstruction may have contributed to the observed discrepancies. Improved reconstructions may be obtained by adding cluster and other correlation functions into reconstruction sets. Correlation functions and the associated stochastic reconstruction algorithms introduced here are universally applicable in soil science, such as for soil classification
Correlation Functions of the One-Dimensional Attractive Bose Gas
Calabrese, Pasquale; Caux, Jean-Sebastien
2007-01-01
The zero-temperature correlation functions of the one-dimensional attractive Bose gas with a delta-function interaction are calculated analytically for any value of the interaction parameter and number of particles, directly from the integrability of the model. We point out a number of interesting features, including zero recoil energy for a large number of particles, analogous to the Moessbauer effect
Gluon 2- and 3-Point Correlation Functions on the Lattice
Parrinello, Claudio
1993-01-01
I present some preliminary results, obtained in collaboration with C. Bernard and A. Soni, for the lattice evaluation of 2- and 3-point gluon correlation functions in momentum space, with emphasis on the amputated 3-gluon vertex function. The final goal of this approach is the study of the running QCD coupling constant as defined from the amputated 3-gluon vertex.
2- and 3-point gluon correlation functions on the lattice
Parrinello, C. (Dept. of Physics, Univ. of Edinburgh (United Kingdom))
1994-04-01
I present some preliminary results, obtained in collaboration with C. Bernard and A. Soni, for the lattice evaluation of 2- and 3-point gluon correlation functions in momentum space, with emphasis on the amputated 3-gluon vertex function. The final goal of this approach is the study of the running QCD coupling constant as defined from the amputated 3-gluon vertex. (orig.)
Time correlation functions and transport coefficients in a dilute superfluid
Kirkpatrick, T.R.; Dorfman, J.R.
1985-01-01
Time correlation functions for the transport coefficients in the linear Landau-Khalatnikov equations are derived on the basis of a formal theory. These Green--Kubo expressions are then explicitly evaluated for a dilute superfluid and the resulting transport coefficiencts are shown to be identical to those obtained previously by using a distribution function method
Nonreciprocal Green’s function retrieval by cross correlation
Wapenaar, C.P.A.
2006-01-01
The cross correlation of two recordings of a diffuse acoustic wave field at different receivers yields the Green’s function between these receivers. In nearly all cases considered so far the wave equation obeys time-reversal invariance and the Green’s function obeys source-receiver reciprocity. Here
Light Meson Distribution Amplitudes
Arthur, R.; Brommel, D.; Donnellan, M.A.; Flynn, J.M.; Juttner, A.; de Lima, H.Pedroso; Rae, T.D.; Sachrajda, C.T.; Samways, B.
2010-01-01
We calculated the first two moments of the light-cone distribution amplitudes for the pseudoscalar mesons ($\\pi$ and $K$) and the longitudinally polarised vector mesons ($\\rho$, $K^*$ and $\\phi$) as part of the UKQCD and RBC collaborations' $N_f=2+1$ domain-wall fermion phenomenology programme. These quantities were obtained with a good precision and, in particular, the expected effects of $SU(3)$-flavour symmetry breaking were observed. Operators were renormalised non-perturbatively and extrapolations to the physical point were made, guided by leading order chiral perturbation theory. The main results presented are for two volumes, $16^3\\times 32$ and $24^3\\times 64$, with a common lattice spacing. Preliminary results for a lattice with a finer lattice spacing, $32^3\\times64$, are discussed and a first look is taken at the use of twisted boundary conditions to extract distribution amplitudes.
Electron Correlation from the Adiabatic Connection for Multireference Wave Functions
Pernal, Katarzyna
2018-01-01
An adiabatic connection (AC) formula for the electron correlation energy is derived for a broad class of multireference wave functions. The AC expression recovers dynamic correlation energy and assures a balanced treatment of the correlation energy. Coupling the AC formalism with the extended random phase approximation allows one to find the correlation energy only from reference one- and two-electron reduced density matrices. If the generalized valence bond perfect pairing model is employed a simple closed-form expression for the approximate AC formula is obtained. This results in the overall M5 scaling of the computation cost making the method one of the most efficient multireference approaches accounting for dynamic electron correlation also for the strongly correlated systems.
Matthews, Daniel J.; Newman, Jeffrey A.
2012-01-01
Cross-correlation techniques provide a promising avenue for calibrating photometric redshifts and determining redshift distributions using spectroscopy which is systematically incomplete (e.g., current deep spectroscopic surveys fail to obtain secure redshifts for 30%-50% or more of the galaxies targeted). In this paper, we improve on the redshift distribution reconstruction methods from our previous work by incorporating full covariance information into our correlation function fits. Correlation function measurements are strongly covariant between angular or spatial bins, and accounting for this in fitting can yield substantial reduction in errors. However, frequently the covariance matrices used in these calculations are determined from a relatively small set (dozens rather than hundreds) of subsamples or mock catalogs, resulting in noisy covariance matrices whose inversion is ill-conditioned and numerically unstable. We present here a method of conditioning the covariance matrix known as ridge regression which results in a more well behaved inversion than other techniques common in large-scale structure studies. We demonstrate that ridge regression significantly improves the determination of correlation function parameters. We then apply these improved techniques to the problem of reconstructing redshift distributions. By incorporating full covariance information, applying ridge regression, and changing the weighting of fields in obtaining average correlation functions, we obtain reductions in the mean redshift distribution reconstruction error of as much as ∼40% compared to previous methods. We provide a description of POWERFIT, an IDL code for performing power-law fits to correlation functions with ridge regression conditioning that we are making publicly available.
Hooft, G. t'; Isidori, G.; Maiani, L.; Polosa, A.D.; Riquer, V.
2008-01-01
We discuss the effect of the instanton induced, six-fermion effective Lagrangian on the decays of the lightest scalar mesons in the diquark-antidiquark picture. This addition allows for a remarkably good description of light scalar meson decays. The same effective Lagrangian produces a mixing of the lightest scalars with the positive parity qq-bar states. Comparing with previous work where the qq-bar mesons are identified with the nonet at 1200-1700 MeV, we find that the mixing required to fit the mass spectrum is in good agreement with the instanton coupling obtained from light scalar decays. A coherent picture of scalar mesons as a mixture of tetraquark states (dominating in the lightest mesons) and heavy qq-bar states (dominating in the heavier mesons) emerges
Oset, E.
1980-01-01
A short review of the topic of mesons in nuclei is exposed paying particular attention to the relationship between several mesonic processes. Special emphasis is put into the microscopic pictures that can ultimately relate all these processes with the elementary coupling of mesons to the nuclear hadronic components. The importance of the short range part of the nuclear interaction opens the doors to a more basic understanding in terms of the quark components of nucleons and isobars. (orig.)
Demographic and Parenting Correlates of Adolescent Sleep Functioning
Zapata Roblyer, Martha I.; Grzywacz, Joseph. G.
2015-01-01
Despite the importance of parenting practices for adolescent adjustment, parenting correlates of adolescent sleep functioning remain understudied. This study delineated patterns of sleep functioning in a sample of ethnically diverse, low-income, adolescents and examined associations among three types of parenting practices (parental involvement, parent-child conflict, and parental control) and adolescent sleep functioning (difficulties initiating sleep and maintaining sleep, and sleep duratio...
Scattering of vector mesons off nucleons
Lutz, M.F.M.; Friman, B.; Wolf, G.
2001-12-01
We construct a relativistic and unitary approach to 'high' energy pion- and photon-nucleon reactions taking the πN, πΔ, ρN, ωN, ηN, K Λ, KΣ final states into account. Our scheme dynamically generates the s- and d-wave nucleon resonances N(1535), N(1650) and N(1520) and isobar resonances Δ(1620) and δ(1700) in terms of quasi-local interaction vertices. The description of photon-induced processes is based on a generalized vector-meson dominance assumption which directly relates the electromagnetic quasi-local 4-point interaction vertices to the corresponding vertices involving the ρ and ω fields. We obtain a satisfactory description of the elastic and inelastic pion- and photon-nucleon scattering data in the channels considered. The resulting s-wave ρ- and ω-nucleon scattering amplitudes are presented. Using these amplitudes we compute the leading density modification of the ρ and ω mass distributions in nuclear matter. We find a repulsive mass shift for the ω meson at small nuclear density but predict considerable strength in resonance-hole like ω-meson modes. Compared to previous calculations our result for the ρ-meson spectral function shows a significantly smaller in-medium effect. This reflects a not too large coupling strength of the N(1520) resonance to the ρN channel. (orig.)
Measurement of spatial correlation functions using image processing techniques
Berryman, J.G.
1985-01-01
A procedure for using digital image processing techniques to measure the spatial correlation functions of composite heterogeneous materials is presented. Methods for eliminating undesirable biases and warping in digitized photographs are discussed. Fourier transform methods and array processor techniques for calculating the spatial correlation functions are treated. By introducing a minimal set of lattice-commensurate triangles, a method of sorting and storing the values of three-point correlation functions in a compact one-dimensional array is developed. Examples are presented at each stage of the analysis using synthetic photographs of cross sections of a model random material (the penetrable sphere model) for which the analytical form of the spatial correlations functions is known. Although results depend somewhat on magnification and on relative volume fraction, it is found that photographs digitized with 512 x 512 pixels generally have sufficiently good statistics for most practical purposes. To illustrate the use of the correlation functions, bounds on conductivity for the penetrable sphere model are calculated with a general numerical scheme developed for treating the singular three-dimensional integrals which must be evaluated
From meson- and photon-nucleon scattering to vector mesons in nuclear matter
Wolf, Gy.; Lutz, M.F.M.; Friman, B.
2003-01-01
A relativistic and unitary approach to pion- and photon-nucleon scattering taking into account the πN, ρN, ωN, ηN, πΔ, KΛ and KΣ channels is presented. The scheme dynamically generates the s- and d-wave baryon resonances N(1535), N(1650), N(1520) and N(1700) and as well as Δ(1620) and Δ(1700) in terms of quasi-local two-body interaction terms. A fair description of the experimental data relevant to the properties of slow vector mesons in nuclear matter is obtained. The resulting s-wave ρ- and ω-meson-nucleon scattering amplitudes which define the leading density modification of the ρ- and ω-meson spectral functions in nuclear matter are presented. (author)
Meson-meson bound state in a 2+1 lattice QCD model with two flavors and strong coupling
Faria da Veiga, Paulo A.; O'Carroll, Michael; Neto, Antonio Francisco
2005-01-01
We consider the existence of bound states of two mesons in an imaginary-time formulation of lattice QCD. We analyze an SU(3) theory with two flavors in 2+1 dimensions and two-dimensional spin matrices. For a small hopping parameter and a sufficiently large glueball mass, as a preliminary, we show the existence of isoscalar and isovector mesonlike particles that have isolated dispersion curves (upper gap up to near the two-particle threshold ∼-4lnκ). The corresponding meson masses are equal up to and including O(κ 3 ) and are asymptotically of order -2lnκ-κ 2 . Considering the zero total isospin sector, we show that there is a meson-meson bound state solution to the Bethe-Salpeter equation in a ladder approximation, below the two-meson threshold, and with binding energy of order bκ 2 ≅0.02359κ 2 . In the context of the strong coupling expansion in κ, we show that there are two sources of meson-meson attraction. One comes from a quark-antiquark exchange. This is not a meson exchange, as the spin indices are not those of the meson particle, and we refer to this as a quasimeson exchange. The other arises from gauge field correlations of four overlapping bonds, two positively oriented and two of opposite orientation. Although the exchange part gives rise to a space range-one attractive potential, the main mechanism for the formation of the bound state comes from the gauge contribution. In our lattice Bethe-Salpeter equation approach, this mechanism is manifested by an attractive distance-zero energy-dependent potential. We recall that no bound state appeared in the one-flavor case, where the repulsive effect of Pauli exclusion is stronger
Long-time tails of correlation and memory functions
Sawada, Isao
2002-11-01
We review the generalized Langevin equation, which is a transformation and reformulation of equation of motion, from the two viewpoints: the projection operator method developed by Mori and the recurrence relations method developed by Lee. The fluctuating forces acting on the Bloch electrons’ current are clarified the strongly colored quantum fluctuations with the spontaneous interband transitions leading to a long-time tail of 1/ t for the envelope of the memory function. The velocity autocorrelation functions in the coupled harmonic oscillator on the Bethe lattice have a long-time tail of 1/t t. The oscillation and the form of decay found in correlation functions affect transport coefficients given by the integrated intensity up to infinity. We also study the force-force correlation functions often used as an approximation to the memory function.
Correlation between HRCT and pulmonary functional tests in cystic fibrosis
Mastellari, Paola; Biggi, Simona; Lombardi, Alfonsa; Zompatori, Maurizio; Grzincich, Gianluigi; Pisi, Giovanna; Spaggiari, Cinzia
2005-01-01
Purpose. To compare the HRCT score by Oikonottlou and air trapping in expiratory scans with pulmonary functional tests and evaluate which radiological criteria are more useful to predict clinical impairment. Materials and methods. From January to September 2003, pulmonary HRCT study was performed in 37 patients (23 males), aged between 7 and 41 years, with cystic fibrosis. In the same day of CT examination they also received a complete functional evaluation. HRCT studies were evaluated by three radiologists blinded to the clinical data and were correlated with the lung function tests. Results. We obtained a high correlation (p=0.01) for two of the HRCT signs: extent of mucus plugging and mosaic perfusion pattern and all function tests. Discussion. Previous studies have demonstrated good correlation between lung function tests, in particular with FEV1 and HRCT signs. Our study differed from previous ones in that we analysed the correlation between lung function tests and with both single and combined CT criteria. Conclusion. Our results suggest that a simplified HRCT store could be useful to evaluate patients with cystic fibrosis [it
Correlation Functions in Open Quantum-Classical Systems
Chang-Yu Hsieh
2013-12-01
Full Text Available Quantum time correlation functions are often the principal objects of interest in experimental investigations of the dynamics of quantum systems. For instance, transport properties, such as diffusion and reaction rate coefficients, can be obtained by integrating these functions. The evaluation of such correlation functions entails sampling from quantum equilibrium density operators and quantum time evolution of operators. For condensed phase and complex systems, where quantum dynamics is difficult to carry out, approximations must often be made to compute these functions. We present a general scheme for the computation of correlation functions, which preserves the full quantum equilibrium structure of the system and approximates the time evolution with quantum-classical Liouville dynamics. Several aspects of the scheme are discussed, including a practical and general approach to sample the quantum equilibrium density, the properties of the quantum-classical Liouville equation in the context of correlation function computations, simulation schemes for the approximate dynamics and their interpretation and connections to other approximate quantum dynamical methods.
Neural correlates of executive functions in patients with obesity.
Ho, Ming-Chou; Chen, Vincent Chin-Hung; Chao, Seh-Huang; Fang, Ching-Tzu; Liu, Yi-Chun; Weng, Jun-Cheng
2018-01-01
Obesity is one of the most challenging problems in human health and is recognized as an important risk factor for many chronic diseases. It remains unclear how the neural systems (e.g., the mesolimbic "reward" and the prefrontal "control" neural systems) are correlated with patients' executive function (EF), conceptualized as the integration of "cool" EF and "hot" EF. "Cool" EF refers to relatively abstract, non-affective operations such as inhibitory control and mental flexibility. "Hot" EF refers to motivationally significant affective operations such as affective decision-making. We tried to find the correlation between structural and functional neuroimaging indices and EF in obese patients. The study population comprised seventeen patients with obesity (seven males and 10 females, BMI = 37.99 ± 5.40, age = 31.82 ± 8.75 year-old) preparing to undergo bariatric surgery. We used noninvasive diffusion tensor imaging, generalized q-sampling imaging, and resting-state functional magnetic resonance imaging to examine the neural correlations between structural and functional neuroimaging indices and EF performances in patients with obesity. We reported that many brain areas are correlated to the patients' EF performances. More interestingly, some correlations may implicate the possible associations of EF and the incentive motivational effects of food. The neural correlation between the left precuneus and middle occipital gyrus and inhibitory control may suggest that patients with a better ability to detect appetitive food may have worse inhibitory control. Also, the neural correlation between the superior frontal blade and affective decision-making may suggest that patients' affective decision-making may be associated with the incentive motivational effects of food. Our results provide evidence suggesting neural correlates of EF in patients with obesity.
Correlation functions and Schwinger-Dyson equations for Penner's model
Chair, N.; Panda, S.
1991-05-01
The free energy of Penner's model exhibits logarithmic singularity in the continuum limit. We show, however, that the one and two point correlators of the usual loop-operators do not exhibit logarithmic singularity. The continuum Schwinger-Dyson equations involving these correlation functions are derived and it is found that within the space of the corresponding couplings, the resulting constraints obey a Virasoro algebra. The puncture operator having the correct (logarithmic) scaling behaviour is identified. (author). 13 refs
Correlation Function Analysis of Fiber Networks: Implications for Thermal Conductivity
Martinez-Garcia, Jorge; Braginsky, Leonid; Shklover, Valery; Lawson, John W.
2011-01-01
The heat transport in highly porous fiber structures is investigated. The fibers are supposed to be thin, but long, so that the number of the inter-fiber connections along each fiber is large. We show that the effective conductivity of such structures can be found from the correlation length of the two-point correlation function of the local conductivities. Estimation of the parameters, determining the conductivity, from the 2D images of the structures is analyzed.
Dynamic polarization in paramagnetic solids and microscopic correlation functions
Boucher, Jean-Paul
1972-01-01
The different effects of Dynamic Nuclear Polarization in paramagnetic solids are described by means of a single thermodynamic formalism. In the case of large exchange interactions, the Overhauser effect correlated with nuclear relaxation time measurements can provide a way of studying correlation functions between electronic spins. This method is used to study the low-frequency behaviour of the microscopic spectral density which should diverge as ω → 0, in the case of a linear exchange chain. (author) [fr
Rare B Meson Decays With Omega Mesons
Zhang, Lei; /Colorado U.
2006-04-24
Rare charmless hadronic B decays are particularly interesting because of their importance in understanding the CP violation, which is essential to explain the matter-antimatter asymmetry in our universe, and of their roles in testing the ''effective'' theory of B physics. The study has been done with the BABAR experiment, which is mainly designed for the study of CP violation in the decays of neutral B mesons, and secondarily for rare processes that become accessible with the high luminosity of the PEP-II B Factory. In a sample of 89 million produced B{bar B} pairs on the BABAR experiment, we observed the decays B{sup 0} {yields} {omega}K{sup 0} and B{sup +} {yields} {omega}{rho}{sup +} for the first time, made more precise measurements for B{sup +} {yields} {omega}h{sup +} and reported tighter upper limits for B {yields} {omega}K* and B{sup 0} {yields} {omega}{rho}{sup 0}.
Santini, Elvira
2008-02-15
The vector meson spectral functions are calculated to the first order in the nuclear matter density assuming the dominant contribution comes from the couplings of the vector mesons to nucleons and nucleon resonances. An attempt is made to reproduce the HADES dilepton production data with the in-medium spectral functions of the vector mesons using the Relativistic Quantum Molecular Dynamics (RQMD) transport model developed earlier for modelling heavy-ion collisions. The results are sensitive to the in-medium broadening of nucleon resonances. A generally good agreement with the HADES data is achieved for selfconsistent treatment of the nucleon resonance broadening and the vector meson spectral functions. (orig.)
Santini, Elvira
2008-01-01
The vector meson spectral functions are calculated to the first order in the nuclear matter density assuming the dominant contribution comes from the couplings of the vector mesons to nucleons and nucleon resonances. An attempt is made to reproduce the HADES dilepton production data with the in-medium spectral functions of the vector mesons using the Relativistic Quantum Molecular Dynamics (RQMD) transport model developed earlier for modelling heavy-ion collisions. The results are sensitive to the in-medium broadening of nucleon resonances. A generally good agreement with the HADES data is achieved for selfconsistent treatment of the nucleon resonance broadening and the vector meson spectral functions. (orig.)
Method of vacuum correlation functions: Results and prospects
Badalian, A. M.; Simonov, Yu. A.; Shevchenko, V. I.
2006-01-01
Basic results obtained within the QCD method of vacuum correlation functions over the past 20 years in the context of investigations into strong-interaction physics at the Institute of Theoretical and Experimental Physics (ITEP, Moscow) are formulated Emphasis is placed primarily on the prospects of the general theory developed within QCD by employing both nonperturbative and perturbative methods. On the basis of ab initio arguments, it is shown that the lowest two field correlation functions play a dominant role in QCD dynamics. A quantitative theory of confinement and deconfinement, as well as of the spectra of light and heavy quarkonia, glueballs, and hybrids, is given in terms of these two correlation functions. Perturbation theory in a nonperturbative vacuum (background perturbation theory) plays a significant role, not possessing drawbacks of conventional perturbation theory and leading to the infrared freezing of the coupling constant α s
The singular multiparticle correlation function and the α-model
Bozek, P.; Ploszajczak, M.
1991-01-01
The comparison is made between the two descriptions of multiparticle correlations using either the α-model or the scale-invariant distribution functions. The case of the strong and weak intermittency is discussed. These two descriptions show similar results for both the scaled factorial moments and the scaled factorial correlators. It is shown that the dimensional projection does not alter this similarity and moreover, it explains an experimentally observed difference between the slopes of factorial moments and factorial correlators. (author) 8 refs.; 3 figs
MesonNet Workshop on Meson Transition Form Factors
Eidelman, S; Hanhart, C; Kubis, B; Kupsc, A; Leupold, S; Moskal, P; Schadmand, S
2012-01-01
The mini-proceedings of the Workshop on Meson Transition Form Factors held in Cracow from May 29th to 30th, 2012 introduce the meson transition form factor project with special emphasis on the interrelations between the various form factors (on-shell, single off-shell, double off-shell). Short summaries of the talks presented at the workshop follow.
Production of charmed mesons in γγ interactions
Braunschweig, W.; Gerhards, R.; Kirschfink, F.J.; Martyn, H.U.; Kolanoski, H.; Hart, J.C.; Saxon, D.H.; Brandt, S.; Holder, M.; Muller, D.; Ritz, S.; Strom, D.; Takashima, M.; Wu Saulan; Zobernig, G.
1990-01-01
Production of charmed mesons in γγ-interactions at PETRA energies has been observed in the TASSO detector. Cross sections for inclusive D *± and D 0 anti D 0 production have been measured. Neutral and charged meson pairs are estimated to be produced with comparable cross sections, and their sum to account for a sizeable function of σ tot (γγ→hadrons) near the canti c threshold. (orig.)
The sewing technique and correlation functions on arbitrary Riemann surfaces
Di Vecchia, P.
1989-01-01
We describe in the case of free bosonic and fermionic theories the sewing procedure, that is a very convenient way for constructing correlation functions of these theories on an arbitrary Riemann surface from their knowledge on the sphere. The fundamental object that results from this construction is the N-point g-loop vertex. It summarizes the information of all correlation functions of the theory on an arbitrary Riemann surface. We then check explicitly the bosonization rules and derive some useful formulas. (orig.)
Estimation of Correlation Functions by the Random Decrement Technique
Brincker, Rune; Krenk, Steen; Jensen, Jakob Laigaard
responses simulated by two SDOF ARMA models loaded by the same bandlimited white noise. The speed and the accuracy of the RDD technique is compared to the Fast Fourier Transform (FFT) technique. The RDD technique does not involve multiplications, but only additions. Therefore, the technique is very fast......The Random Decrement (RDD) Technique is a versatile technique for characterization of random signals in the time domain. In this paper a short review of the theoretical basis is given, and the technique is illustrated by estimating auto-correlation functions and cross-correlation functions on modal...
Estimation of Correlation Functions by the Random Decrement Technique
Brincker, Rune; Krenk, Steen; Jensen, Jacob Laigaard
1991-01-01
responses simulated by two SDOF ARMA models loaded by the same band-limited white noise. The speed and the accuracy of the RDD technique is compared to the Fast Fourier Transform (FFT) technique. The RDD technique does not involve multiplications, but only additions. Therefore, the technique is very fast......The Random Decrement (RDD) Technique is a versatile technique for characterization of random signals in the time domain. In this paper a short review of the theoretical basis is given, and the technique is illustrated by estimating auto-correlation functions and cross-correlation functions on modal...
Estimation of Correlation Functions by the Random Decrement Technique
Brincker, Rune; Krenk, Steen; Jensen, Jakob Laigaard
1992-01-01
responses simulated by two SDOF ARMA models loaded by the same bandlimited white noise. The speed and the accuracy of the RDD technique is compared to the Fast Fourier Transform (FFT) technique. The RDD technique does not involve multiplications, but only additions. Therefore, the technique is very fast......The Random Decrement (RDD) Technique is a versatile technique for characterization of random signals in the time domain. In this paper a short review of the theoretical basis is given, and the technique is illustrated by estimating auto-correlation functions and cross-correlation functions on modal...
Kok, S
2012-07-01
Full Text Available continuously as the correlation function hyper-parameters approach zero. Since the global minimizer of the maximum likelihood function is an asymptote in this case, it is unclear if maximum likelihood estimation (MLE) remains valid. Numerical ill...
Correlation functions of the spin chains. Algebraic Bethe Ansatz approach
Kitanine, N.
2007-09-01
Spin chains are the basic elements of integrable quantum models. These models have direct applications in condense matter theory, in statistical physics, in quantum optics, in field theory and even in string theory but they are also important because they enable us to solve, in an exact manner, non-perturbative phenomena that otherwise would stay unresolved. The method described in this work is based on the algebraic Bethe Ansatz. It is shown how this method can be used for the computation of null temperature correlation functions of the Heisenberg 1/2 spin chain. The important point of this approach is the solution of the inverse quantum problem given by the XXZ spin chain. This solution as well as a simple formulae for the scalar product of the Bethe states, have enabled us to get the most basic correlation functions under the form of multiple integrals. The formalism of multiple integrals open the way for asymptotic analysis for a few physical quantities like the probability of vacuum formation. It is worth noticing that this formalism can give exact results for two-point functions that are the most important correlation functions for applications. A relationship has been discovered between these multiple integrals and the sum of the form factors. The results have been extended to dynamical correlation functions. (A.C.)
Exploring a new S U (4 ) symmetry of meson interpolators
Glozman, L. Ya.; Pak, M.
2015-07-01
In recent lattice calculations it has been discovered that mesons upon truncation of the quasizero modes of the Dirac operator obey a symmetry larger than the S U (2 )L×S U (2 )R×U (1 )A symmetry of the QCD Lagrangian. This symmetry has been suggested to be S U (4 )⊃S U (2 )L×S U (2 )R×U (1 )A that mixes not only the u- and d-quarks of a given chirality, but also the left- and right-handed components. Here it is demonstrated that bilinear q ¯q interpolating fields of a given spin J ≥1 transform into each other according to irreducible representations of S U (4 ) or, in general, S U (2 NF). This fact together with the coincidence of the correlation functions establishes S U (4 ) as a symmetry of the J ≥1 mesons upon quasizero mode reduction. It is shown that this symmetry is a symmetry of the confining instantaneous charge-charge interaction in QCD. Different subgroups of S U (4 ) as well as the S U (4 ) algebra are explored.
Direct Photon and Neutral Mesons Measurements with the ALICE Detector
Matyja, Adam
2016-01-01
The ALICE experiment at LHC is dedicated to studies of the Quark– Gluon Plasma (QGP) state, which is going to be created in heavy-ion collisions. Both photons and neutral mesons are excellent probes for QGP formation. Photons are produced during the different stages of the expan- sion of the initial hot matter fireball. They do not interact strongly with the medium and passing through it, they carry information on their emis- sion point. The prompt photons which are formed at the early stage of the collision enable us to test perturbative QCD constraining parton distri- butions and fragmentation functions. Looking into the regime of thermal photons, one can extract the temperature of the medium. The medium- induced energy loss of particles can be investigated via the measurement of neutral meson spectra for different centrality classes as well as via neutral meson–hadron correlations. A decrease of the nuclear modification factor ( R AA ) with centrality of the collision is observed. The suppression of th...
Two-body spectra of pseudoscalar mesons with an O(a2)-improved lattice action using Wilson fermions
Fiebig, H.R.; Mihaly, A.; Woloshyn, R.M.
1998-01-01
We extend our calculations with the second-order tree-level and tadpole improved next-nearest-neighbor action to meson-meson systems. Correlation matrices built from interpolating fields representing two pseudoscalar mesons (π-π) with relative momenta vector-p are diagonalized, and the mass spectrum is extracted. Link variable fuzzing and operator smearing at both sinks and sources is employed. Calculations are presented for two values of the hopping parameter. The spectrum is used to discuss the residual interaction in the meson-meson system. (orig.)
Fiebig, H.R. [FIU-University Park, Miami, FL (United States). Phys. Dept.; Markum, H.; Rabitsch, K. [Institut fuer Kernphysik, Technische Universitaet Wien, 1040 Vienna (Austria); Mihaly, A. [Department of Theoretical Physics, Lajos Kossuth University, 4010 Debrecen (Hungary); Woloshyn, R.M. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada)
1998-04-01
We extend our calculations with the second-order tree-level and tadpole improved next-nearest-neighbor action to meson-meson systems. Correlation matrices built from interpolating fields representing two pseudoscalar mesons ({pi}-{pi}) with relative momenta vector-p are diagonalized, and the mass spectrum is extracted. Link variable fuzzing and operator smearing at both sinks and sources is employed. Calculations are presented for two values of the hopping parameter. The spectrum is used to discuss the residual interaction in the meson-meson system. (orig.). 6 refs.
The Potts model and flows. 1. The pair correlation function
Essam, J.W.; Tsallis, C.
1985-01-01
It is shown that the partition function for the lambda-state Potts model with pair-interactions is related to the expected number of integer mod-lambda flows in a percolation model. The relation is generalised to the pair correlation function. The resulting high temperature expansion coefficients are shown to be the flow polynomials of graph theory. An observation of Tsallis and Levy concerning the equivalent transmissivity of a cluster is also proved. (Author) [pt
Structural and functional correlates of epileptogenesis — Does gender matter?
Savic, Ivanka; Engel, Jerome
2016-01-01
In the majority of neuropsychiatric conditions, marked gender-based differences have been found in the epidemiology, clinical manifestations, and therapy of disease. One possible reason is that sex differences in cerebral morphology, structural and functional connections, render men and women differentially vulnerable to various disease processes. The present review addresses this issue with respect to the functional and structural correlates to some forms of epilepsy. PMID:24943053
Structural and functional correlates of hypnotic depth and suggestibility.
McGeown, William Jonathan; Mazzoni, Giuliana; Vannucci, Manila; Venneri, Annalena
2015-02-28
This study explores whether self-reported depth of hypnosis and hypnotic suggestibility are associated with individual differences in neuroanatomy and/or levels of functional connectivity. Twenty-nine people varying in suggestibility were recruited and underwent structural, and after a hypnotic induction, functional magnetic resonance imaging at rest. We used voxel-based morphometry to assess the correlation of grey matter (GM) and white matter (WM) against the independent variables: depth of hypnosis, level of relaxation and hypnotic suggestibility. Functional networks identified with independent components analysis were regressed with the independent variables. Hypnotic depth ratings were positively correlated with GM volume in the frontal cortex and the anterior cingulate cortex (ACC). Hypnotic suggestibility was positively correlated with GM volume in the left temporal-occipital cortex. Relaxation ratings did not correlate significantly with GM volume and none of the independent variables correlated with regional WM volume measures. Self-reported deeper levels of hypnosis were associated with less connectivity within the anterior default mode network. Taken together, the results suggest that the greater GM volume in the medial frontal cortex and ACC, and lower connectivity in the DMN during hypnosis facilitate experiences of greater hypnotic depth. The patterns of results suggest that hypnotic depth and hypnotic suggestibility should not be considered synonyms. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Exotic meson spectroscopy with CLAS
Adams, G.; Napolitano, J. [Rensselaer Polytechnic Inst., Troy, NY (United States)
1994-04-01
The identification and study of mesons with explicit gluonic degrees of freedom will provide major constraints on nonperturbative QCD and models thereof. CLAS will provide a unique opportunity for studying these resonances by measuring photoproduction of multi-meson final states.
Cosmological forecasts from photometric measurements of the angular correlation function
Sobreira, F.; Rosenfeld, R.; Simoni, F. de; Costa, L. A. N. da; Maia, M. A. G.; Makler, M.
2011-01-01
We study forecasts for the accuracy of the determination of cosmological parameters from future large-scale photometric surveys obtained using the full shape of the 2-point galaxy angular correlation function. The effects of linear redshift-space distortion, photometric redshift Gaussian errors, galaxy bias and nonlinearities in the power spectrum are included on our analysis. The Fisher information matrix is constructed with the full covariance matrix, including the correlation between nearby redshift shells arising from the photometric redshift error. We show that under some reasonable assumptions, a survey such as the imminent Dark Energy Survey should be able to constrain the dark energy equation of state parameter w and the cold dark matter density Ω cdm with a precision of the order of 20% and 13%, respectively, from the full shape of the angular correlation function alone. When combined with priors from other observations the precision in the determination of these parameters improve to 8% and 4%, respectively.
Evaluation of time correlation functions from a generalized Enskog equation
Yip, S.; Alley, W.E.; Alder, B.J.
1982-01-01
Numerical results for the density and current correlation functions in dense hard-shape fluids are obtained from a kinetic equation which is the extension of the linearized Enskog equation to finite wavelengths in order to demonstrate the convergence of the method of solution. Comparison is made to a previously proposed approximate solution.
Evaluation of time correlation functions from a generalized Enskog equation
Yip, S.; Alley, W.E.; Alder, B.J.
1982-01-01
Numerical results for the density and current correlation functions in dense hard-shape fluids are obtained from a kinetic equation which is the extension of the linearized Enskog equation to finite wavelengths in order to demonstrate the convergence of the method of solution. Comparison is made to a previously proposed approximate solution
The pair correlation function of spatial Hawkes processes
Møller, Jesper; Torrisi, Giovanni Luca
2007-01-01
Spatial Hawkes processes can be considered as spatial versions of classical Hawkes processes. We derive the pair correlation function of stationary spatial Hawkes processes and discuss the connection to the Bartlett spectrum and other summary statistics. Particularly, results for Gaussian fertility...... rates and the extension to spatial Hawkes processes with random fertility rates are discussed....
A two-point correlation function for Galactic halo stars
Cooper, A. P.; Cole, S.; Frenk, C. S.; Helmi, A.
2011-01-01
We describe a correlation function statistic that quantifies the amount of spatial and kinematic substructure in the stellar halo. We test this statistic using model stellar halo realizations constructed from the Aquarius suite of six high-resolution cosmological N-body simulations, in combination
Correlation functions formed by a femtosecond pulse interferometer
Cui, M.; Bhattacharya, N.; Urbach, H.P.; Van den berg, S.A.
2008-01-01
We experimentally demonstrate that a stabilized femtosecond frequency comb can be applied as a tool for distance measurement. The scheme is based on optical interference between individual pulses in a Michelson type interferometer. The cross-correlation functions between individual pulses with a
Density-correlation functions in Calogero-Sutherland models
Minahan, J.A.; Polychronakos, A.P.
1994-01-01
Using arguments from two-dimensional Yang-Mills theory and the collective coordinate formulation of the Calogero-Sutherland model, we conjecture the dynamical density-correlation function for coupling l and 1/l, where l is an integer. We present overwhelming evidence that the conjecture is indeed correct
Density correlation functions in Calogero-Sutherland models
Minahan, Joseph A.; Joseph A Minahan; Alexios P Polychronakos
1994-01-01
Using arguments from two dimensional Yang-Mills theory and the collective coordinate formulation of the Calogero-Sutherland model, we conjecture the dynamical density correlation function for coupling l and 1/l, where l is an integer. We present overwhelming evidence that the conjecture is indeed correct.
Strange mesonic transition form factor
Goity, J.L.; Musolf, M.J.
1996-01-01
The strange-quark vector current ρ-to-π meson transition form factor is computed at one-loop order using strange meson intermediate states. A comparison is made with a φ-meson dominance model estimate. We find that one-loop contributions are comparable in magnitude to those predicted by φ-meson dominance. It is possible that the one-loop contribution can make the matrix element as large as those of the electromagnetic current mediating vector meson radiative decays. However, due to the quadratic dependence of the one-loop results on the hadronic form factor cutoff mass, a large uncertainty in the estimate of the loops is unavoidable. These results indicate that non-nucleonic strange quarks could contribute appreciable in moderate-parallel Q 2 parallel parity-violating electron-nucleus scattering measurements aimed at probing the strange-quark content of the nucleon. copyright 1996 The American Physical Society
Demographic and Parenting Correlates of Adolescent Sleep Functioning.
Zapata Roblyer, Martha I; Grzywacz, Joseph G
2015-11-01
Despite the importance of parenting practices for adolescent adjustment, parenting correlates of adolescent sleep functioning remain understudied. This study delineated patterns of sleep functioning in a sample of ethnically diverse, low-income, adolescents and examined associations among three types of parenting practices (parental involvement, parent-child conflict, and parental control) and adolescent sleep functioning (difficulties initiating sleep and maintaining sleep, and sleep duration). Adolescents ( N = 91, 11-19 years old) self-reported on sleep functioning and parenting practices. Results showed that in the preceding month, 60.5% of adolescents had difficulties initiating sleep and 73.6% had difficulties maintaining sleep. Most adolescents slept 8 or more hours per night, but 30.7% slept less than 8 hours. Latino adolescents slept longer and had fewer difficulties maintaining sleep than non-Latino. High school students had fewer difficulties maintaining sleep than their middle school counterparts; conversely, older adolescents experienced shorter sleep duration than younger ones. Adolescents whose parents had post-secondary education had shorter sleep duration than those whose parents had not graduated from high school. Parental control was correlated with fewer difficulties initiating sleep, whereas parent-child conflict was correlated with more difficulties maintaining sleep. There were no parenting correlates of sleep duration. Latino adolescents had better sleep profiles than non-Latino ones. Regression analyses showed that parental control and parent-child conflict were associated with adolescent sleep functioning across ethnicities. Results suggest that parenting practices, as well as demographic characteristics, are associated with adolescent sleep functioning and should be taken into account in interventions aimed at improving sleep functioning among adolescents.
Euclidean fields: vector mesons and photons
Loffelholz, J.
1979-01-01
Free transverse vector fields of mass >= 0 are studied. The model is related to the usual free vector meson and electromagnetic quantum field theories by extension of the field operators from transverse to arbitrary test functions. The one-particle states in transverse gauge and their localization are described. Reflexion positivity is proved and derived are free Feynman-Kac-Nelson formulas. An Euclidean approach to a photon field in a spherical world using dilatation covariance and inversions is given
A local dynamic correlation function from inelastic neutron scattering
McQueeney, R.J.
1997-01-01
Information about local and dynamic atomic correlations can be obtained from inelastic neutron scattering measurements by Fourier transform of the Q-dependent intensity oscillations at a particular frequency. A local dynamic structure function, S(r,ω), is defined from the dynamic scattering function, S(Q,ω), such that the elastic and frequency-integrated limits correspond to the average and instantaneous pair-distribution functions, respectively. As an example, S(r,ω) is calculated for polycrystalline aluminum in a model where atomic motions are entirely due to harmonic phonons
Correlation between hypertension and cognitive function in elderly
Fitri, F. I.; Rambe, A. S.
2018-03-01
Hypertension and cognitive impairment are common disorders among elderly adults, and their prevalences tend to rise as the population ages. This study aimed to determine the correlation between hypertension and cognitive function in elderly. It was a cross-sectional study involving 62 elderly subjects. All subjects underwent physical and neurologic examination and Montreal Cognitive Assessment-Indonesian Version (MoCA-INA) to assess cognitive function. This study included 62 subjects consisted of 26 males (41.9%) and 36 females (58.1%). There were 24 subjects (38.2%) with hypertension and 38 (61.3%) normal elderly subjects. The mean age was 65.71±4.49 years old. There were no significant differences in demographic characteristics, total MoCA-INA scores, and scores based on cognitive domains between two groups, except for visuospatial and executive function (p=0.026). There was a significant correlation between hypertension and visuospatial and executive function (r=0.301, p=0.017). Hypertension is correlated with cognitive impairment mainly on visuospatial and executive function in elderly.
Describing a Strongly Correlated Model System with Density Functional Theory.
Kong, Jing; Proynov, Emil; Yu, Jianguo; Pachter, Ruth
2017-07-06
The linear chain of hydrogen atoms, a basic prototype for the transition from a metal to Mott insulator, is studied with a recent density functional theory model functional for nondynamic and strong correlation. The computed cohesive energy curve for the transition agrees well with accurate literature results. The variation of the electronic structure in this transition is characterized with a density functional descriptor that yields the atomic population of effectively localized electrons. These new methods are also applied to the study of the Peierls dimerization of the stretched even-spaced Mott insulator to a chain of H 2 molecules, a different insulator. The transitions among the two insulating states and the metallic state of the hydrogen chain system are depicted in a semiquantitative phase diagram. Overall, we demonstrate the capability of studying strongly correlated materials with a mean-field model at the fundamental level, in contrast to the general pessimistic view on such a feasibility.
A new quantum statistical evaluation method for time correlation functions
Loss, D.; Schoeller, H.
1989-01-01
Considering a system of N identical interacting particles, which obey Fermi-Dirac or Bose-Einstein statistics, the authors derive new formulas for correlation functions of the type C(t) = i= 1 N A i (t) Σ j=1 N B j > (where B j is diagonal in the free-particle states) in the thermodynamic limit. Thereby they apply and extend a superoperator formalism, recently developed for the derivation of long-time tails in semiclassical systems. As an illustrative application, the Boltzmann equation value of the time-integrated correlation function C(t) is derived in a straight-forward manner. Due to exchange effects, the obtained t-matrix and the resulting scattering cross section, which occurs in the Boltzmann collision operator, are now functionals of the Fermi-Dirac or Bose-Einstein distribution
Correlation functions of one-dimensional Lieb-Liniger anyons
Patu, Ovidiu I; Korepin, Vladimir E; Averin, Dmitri V
2007-01-01
We have investigated the properties of a model of 1D anyons interacting through a δ-function repulsive potential. The structure of the quasi-periodic boundary conditions for the anyonic field operators and the many-anyon wavefunctions is clarified. The spectrum of the low-lying excitations including the particle-hole excitations is calculated for periodic and twisted boundary conditions. Using the ideas of the conformal field theory we obtain the large-distance asymptotics of the density and field correlation function at the critical temperature T = 0 and at small finite temperatures. Our expression for the field correlation function extends the results in the literature obtained for harmonic quantum anyonic fluids
Grube, Boris
2015-01-01
The COmmon Muon and Proton Apparatus for Structure and Spectroscopy (COMPASS) is a multi-purpose fixed-target experiment at the CERN Super Proton Synchrotron (SPS) aimed at studying the structure and spectrum of hadrons. The two-stage spectrometer has a good acceptance for charged as well as neutral particles over a wide kinematic range and thus allows to access a wide range of reactions. Light mesons are studied with negative (mostly $\\pi^-$) and positive ($p$, $\\pi^+$) hadron beams with a momentum of 190 GeV/$c$. The spectrum of light mesons is investigated in various final states produced in diffractive dissociation reactions at squared four-momentum transfers to the target between 0.1 and 1.0 $(\\text{GeV}/c)^2$. The flagship channel is the $\\pi^-\\pi^+\\pi^-$ final state, for which COMPASS has recorded the currently largest data sample. These data not only allow to measure the properties of known resonances with high precision, but also to search for new states. Among these is a new resonance-like signal, t...
Meson radiobiology and therapy
Kilgerman, M.M.
1975-08-01
High-linear energy transfer radiation (neutrons, heavy ions, and pions) have a greater relative biological effectiveness than low-linear energy transfer radiation by depositing a high density of ionization in irradiated cells. This overcomes the protective effect of oxygen; decreases the variation in sensitivity among the several stages of the cell cycles; and, inhibits the repair of sublethal damage as compared to x-rays, gamma rays, electrons and protons. Negative pi mesons (pions), appear particularly suited for radiation therapy as their penetration and depth-dose profiles lend themselves to shaping the high dose area to the tumor size and location. Preliminary biological experiments with pions produced at the Los Alamos Meson Physics Facility studied cell survival at various radiation depths and cell cycle sensitivity. Histologic study of data from the first human experiments indicated severe tumor cell destruction by pions as compared to x-rays in treating malignant melanoma skin nodules, without increased effects on dermal elements. (U.S.)
Crowe, K.M.
1992-01-01
The activities of this group are primarily concerned with experiments using the Crystal Barrel Detector. This detector is installed and operating at the Low Energy Antiproton Ring (LEAR) at CERN. QCD, the modem theory of the strong interaction, is reasonably well understood at high energies, but unfortunately, low-energy QCD is still not well understood, and is far from being adequately tested. The Crystal Barrel experiments are designed to provide some of the tests. The basic line of research involves meson spectroscopy, analyses bearing on the quark and/or gluon content of nuclear states, and the exploration of mechanisms and rules which govern p bar p annihilation dynamics. The Crystal Barrel Detector detects and identifies charged and neutral particles with a geometric acceptance close to 100%. The principal component of the detector is an array of 1,380 CsI(TI) crystals. These crystals surround a Jet Drift Chamber (JDC), located in a 1.5 Tesla magnetic field, which measures the momentum and dE/dx of charged particles. One of the very interesting physics goals of the detector is a search for exotic mesonic states -- glueballs and hybrids. Annihilation at rest will be studied with both liquid and gaseous hydrogen targets. The gaseous target offers the possibility of triggering on atomic L-shell X rays so that specific initial angular momentum states can be studied.These topics as well as other related topics are discussed in this report
Grube, Boris
2016-11-29
The goal of the COMPASS experiment at CERN is to study the structure and dynamics of hadrons. The two-stage spectrometer used by the experiment has large acceptance and covers a wide kinematic range for charged as well as neutral particles and can therefore measure a wide range of reactions. The spectroscopy of light mesons is performed with negative (mostly $\\pi^-$) and positive ($p$, $\\pi^+$) hadron beams with a momentum of 190 GeV/$c$. The light-meson spectrum is measured in different final states produced in diffractive dissociation reactions with squared four-momentum transfer $t$ to the target between 0.1 and 1.0 $(\\text{GeV}/c)^2$. The flagship channel is the $\\pi^-\\pi^-\\pi^+$ final state, for which COMPASS has recorded the currently world's largest data sample. These data not only allow to measure the properties of known resonances with high precision, but also to observe new states. Among these is a new axial-vector signal, the $a_1(1420)$, with unusual properties. Novel analysis techniques have been...
Liu, Lon-chang.
1989-01-01
Since the advent of pion factories, an impressive amount of information about the nuclear dynamics of the Δ(1232) pion- nucleon resonance has been obtained. The study of this isospin-3/2 resonance has greatly benefited from the fact that π/sup /minus//n and π + p systems are pure I = 3/2 states, which couple only to the Δ in the resonance region. Such isospin selectivity of the pion does not exist, however, for the I = 1/2 N* resonances because it is not possible to form a pure I = 1/2 state with a pion and a nucleon. Eta mesons have zero isospin. Consequently, the /eta/N systems are in a pure I = 1/2 state, and /eta/ can be used to tag those N* resonances to which it strongly couples. We will briefly review the πN interaction from the threshold region to c.m. energy √s ≅1600 MeV. We shall see how improved πN data can help the study of πN interactions. I shall discuss what new information about the hadronic interaction can be learned from the study of eta production in pp collisions. The behavior of eta meson in nuclei will be discussed. The interesting question of the quark structure of /eta/(549) and /eta/'(958) will also be discussed within the framework of a simple model. 19 refs., 13 figs
Invariant mass dependence of two-pion inclusive correlation functions
Berger, E.L.; Singer, R.; Thomas, G.H.; Kafka, T.
1976-06-01
High energy two-particle inclusive correlations are studied as a function of the invariant mass M of the pair. Using data from 205 GeV/c pp interactions, one compares the correlation functions C(M) for (+-) and (--) pairs of produced pions. Strong positive correlations are observed in both distributions in the form of a broad threshold enhancement at small M. The decrease of C(M) as M increases is interpreted in the Mueller-Regge framework. From the M dependence of C +- one extracts an effective trajectory intercept of roughly α(0) approximately equal to 0.5 +- 0.1, consistent with the (rho,f) pair. For the exotic (--) system, one finds a low intercept, α(0) approximately equal to -0.5. A rho resonance signal is observed above background in C +- (M). Near threshold, effects suggestive of Bose symmetry are seen but are not conclusive. In an exclusive picture, one relates most of the correlation in the threshold region to resonances involving three or more pions. One also examines the joint correlations in M and the azimuthal angle phi
Instanton and tensor-force effects in the strong decays of mesons
Bonnaz, R.; Silvestre-Brac, B.
2001-01-01
The strong decays of mesons are studied in the framework of the 3 P 0 model with a momentum-dependent vertex. The mesons wave functions are obtained from quark-antiquark potentials including a finite quark size, instanton effects, spin-orbit and tensor-force effects. Several prescriptions for treating the decays into three mesons are proposed and analyzed. Comparison to experimental data is presented in detail. (author)
Correlation function of weakly interacting bosons in a disordered lattice
Deissler, B; Lucioni, E; Modugno, M; Roati, G; Tanzi, L; Zaccanti, M; Inguscio, M; Modugno, G, E-mail: deissler@lens.unifi.it, E-mail: modugno@lens.unifi.it [LENS and Dipartimento di Fisica e Astronomia, Universita di Firenze, 50019 Sesto Fiorentino (Italy)
2011-02-15
One of the most important issues in disordered systems is the interplay of the disorder and repulsive interactions. Several recent experimental advances on this topic have been made with ultracold atoms, in particular the observation of Anderson localization and the realization of the disordered Bose-Hubbard model. There are, however, still questions as to how to differentiate the complex insulating phases resulting from this interplay, and how to measure the size of the superfluid fragments that these phases entail. It has been suggested that the correlation function of such a system can give new insights, but so far very little experimental investigation has been performed. Here, we show the first experimental analysis of the correlation function for a weakly interacting, bosonic system in a quasiperiodic lattice. We observe an increase in the correlation length as well as a change in the shape of the correlation function in the delocalization crossover from Anderson glass to coherent, extended state. In between, the experiment indicates the formation of progressively larger coherent fragments, consistent with a fragmented BEC, or Bose glass.
Correlation function of weakly interacting bosons in a disordered lattice
Deissler, B; Lucioni, E; Modugno, M; Roati, G; Tanzi, L; Zaccanti, M; Inguscio, M; Modugno, G
2011-01-01
One of the most important issues in disordered systems is the interplay of the disorder and repulsive interactions. Several recent experimental advances on this topic have been made with ultracold atoms, in particular the observation of Anderson localization and the realization of the disordered Bose-Hubbard model. There are, however, still questions as to how to differentiate the complex insulating phases resulting from this interplay, and how to measure the size of the superfluid fragments that these phases entail. It has been suggested that the correlation function of such a system can give new insights, but so far very little experimental investigation has been performed. Here, we show the first experimental analysis of the correlation function for a weakly interacting, bosonic system in a quasiperiodic lattice. We observe an increase in the correlation length as well as a change in the shape of the correlation function in the delocalization crossover from Anderson glass to coherent, extended state. In between, the experiment indicates the formation of progressively larger coherent fragments, consistent with a fragmented BEC, or Bose glass.
Measurement of the B$_{d}^{0}$ meson oscillation frequency
Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alpat, B; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Antreasyan, D; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banicz, K; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Borgia, B; Boucham, A; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Brambilla, Elena; Branson, J G; Brigljevic, V; Brock, I C; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Buytenhuijs, A O; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Caria, M; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Castello, R; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chan, A; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Choi, M T; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; De Boeck, H; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dorne, I; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Fernández, D; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hangarter, K; Hartmann, B; Hasan, A; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Ilyas, M M; Innocente, Vincenzo; Janssen, H; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamyshkov, Yu A; Kapinos, P; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Korolko, I; Koutsenko, V F; Krämer, R W; Kramer, T; Krenz, W; Kuijten, H; Kunin, A; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee Jae Sik; Lee, K Y; Leggett, C; Le Goff, J M; Leiste, R; Lenti, M; Leonardi, E; Levchenko, P M; Li Chuan; Lieb, E H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Ludovici, L; Luminari, L; Lustermann, W; Ma Wen Gan; Macchiolo, A; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Monteleoni, B; Moore, R; Morganti, S; Mount, R; Müller, S; Muheim, F; Nagy, E; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nippe, A; Nowak, H; Organtini, G; Ostonen, R; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Raghavan, R; Rahal-Callot, G; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riemers, B C; Riles, K; Rind, O; Ro, S; Robohm, A; Rodin, J; Rodríguez-Calonge, F J; Roe, B P; Röhner, S; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Rykaczewski, H; Salicio, J; Sánchez, E; Santocchia, A; Sarakinos, M E; Sarkar, S; Sassowsky, M; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Schneegans, M; Schöneich, B; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Sens, Johannes C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Sticozzi, F; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonisch, F; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Y F; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino
1996-01-01
Time-dependent \\Bd-\\Bbd\\ mixing is studied using 1.5 million hadronic Z decays collected by L3. Semileptonic B decays are selected by requiring at least one reconstructed lepton in both thrust hemispheres. Charge correlations between the tagged leptons are studied as a function of proper time. The proper time of the b-hadron decay is measured by reconstructing the production and decay vertices using a silicon microvertex detector. The measured \\Bd\\ meson oscillation frequency corresponds to a mass difference \\Dmd\\ between the two \\Bd\\ mass eigenstates of \\begin{displaymath} \\Dmd = \\left( 0.496 ^{+ 0.055}_{- 0.051}\\ \\mathrm{(stat)} \\pm{ 0.043}\\ \\mathrm{(syst)} \\right)\\ \\mathrm{ps}^{-1}. \\end{displaymath}
Meson exchange and neutral weak currents
Beck, D.H. [Univ. of Illinois, Urbana, IL (United States)
1994-04-01
Measurements of parity-violating electron scattering asymmetries to determine weak neutral currents in nuclei will be effected by the presence of meson exchange currents. Present low momentum transfer calculations, based on a flavor independent framework, show these effects to be small. In general, however, as the momentum transfer increases to values typical of deep-inelastic scattering, fragmentation functions show a clear flavor dependence. It is suggested that a good experimental starting point for understanding the flavor dependence of meson production and exchange currents is the Q{sup 2} dependence of parity-violating asymmetry in inclusive single pion electroproduction. A CEBAF facility with doubled energy is necessary to approach momentum transfers where this process begins to scale.
Nutt, W.T.
1976-01-01
A meson-theoretic model of the intermediate range nucleon-nucleon potential is presented with emphasis placed on the two-pion exchange contribution. The Bethe-Salpeter equation is reduced, by the Blankenbecler-Sugar technique, to a Lippmann-Schwinger equation, from which an approximate nonlocal, energy-dependent potential is obtained. The nucleon-antinucleon pair contribution, which plagues meson-theoretical two-pion calculations, is suppressed by the complex poles of the one-nucleon Green's function. The importance of the retention of the explicit energy dependence of the potential is demonstrated by calculating the off-shell scattering matrices. The potential is presented in a linearized (in energy) form with the core region adjusted to produce a fit to low energy data
A transverse lattice QCD model for mesons
Patel, Apoorva D.; Ratabole, Raghunath
2004-03-01
QCD is analysed with two light-front continuum dimensions and two transverse lattice dimensions. In the limit of large number of colours and strong transverse gauge coupling, the contributions of light-front and transverse directions factorise in the dynamics, and the theory can be analytically solved in a closed form. An integral equation is obtained, describing the properties of mesons, which generalises the 't Hooft equation by including spin degrees of freedom. The meson spectrum, light-front wavefunctions and form factors can be obtained by solving this equation numerically. These results would be a good starting point to model QCD observables which only weakly depend on transverse directions, e.g. deep inelastic scattering structure functions.
Exclusive vector meson production at HERA
Szuba, Dorota [Hamburg University, Hamburg (Germany); Collaboration: H1 Collaboration; ZEUS Collaboration
2013-04-15
The exclusive photoproduction of {Upsilon} has been studied with the ZEUS detector in ep collisions at HERA. The exponential slope, b, of the |t|-dependence of the cross section, where t is the squared four-momentum transfer at the proton vertex, has been measured. This constitutes the first measurement of the |t|-dependence of the {gamma}p{yields}{Upsilon}p cross section. The differential crosssections as a function of t at lower energies of {gamma}p centre-of-mass has been studied in exclusive diffractive photoproduction of J/{psi} mesons with the H1 detector. The exclusive electroproduction of two pions has been measured by the ZEUS experiment. The two-pion invariant-mass distribution is interpreted in terms of the pion electromagnetic form factor, assuming that the studied mass range includes the contributions of the {rho}, {rho} Prime and . {rho}'' vector-meson states.
Exclusive vector meson production at HERA
Szuba, Dorota
2013-01-01
The exclusive photoproduction of Υ has been studied with the ZEUS detector in ep collisions at HERA. The exponential slope, b, of the |t|-dependence of the cross section, where t is the squared four-momentum transfer at the proton vertex, has been measured. This constitutes the first measurement of the |t|-dependence of the γp→Υp cross section. The differential crosssections as a function of t at lower energies of γp centre-of-mass has been studied in exclusive diffractive photoproduction of J/ψ mesons with the H1 detector. The exclusive electroproduction of two pions has been measured by the ZEUS experiment. The two-pion invariant-mass distribution is interpreted in terms of the pion electromagnetic form factor, assuming that the studied mass range includes the contributions of the ρ, ρ′ and . ρ'' vector-meson states.
Charmed meson production at LHCb
Müller, Dominik
2016-01-01
Measurements of charm meson production are important tests for QCD predictions and LHCb is uniquely suited to perform these measurements in the forward region. This paper summarises recent charm meson production measurements performed by LHCb of J/ψ and open charm mesons and the associated production of ϒ and open charm mesons. The J/ψ and open charm meson measurements are performed with data recorded in Run 2 of the Large Hadron Collider. With proton-proton collisions at √s = 13 TeV, these open a new regime in which QCD predictions for charm meson production may be precisely tested. Furthermore, ratios of cross-sections at different centre-of-mass energies benefit of cancellation of both experimental and theoretical uncertainties, providing a new sensitive test of the QCD calculations. Measurements of ϒ and open charm meson associated production are performed using √s = 7 TeV and √s = 8 TeV data and constitute the first observation of this production channel.
A partitioned correlation function interaction approach for describing electron correlation in atoms
Verdebout, S; Godefroid, M; Rynkun, P; Jönsson, P; Gaigalas, G; Fischer, C Froese
2013-01-01
The traditional multiconfiguration Hartree–Fock (MCHF) and configuration interaction (CI) methods are based on a single orthonormal orbital basis. For atoms with many closed core shells, or complicated shell structures, a large orbital basis is needed to saturate the different electron correlation effects such as valence, core–valence and correlation within the core shells. The large orbital basis leads to massive configuration state function (CSF) expansions that are difficult to handle, even on large computer systems. We show that it is possible to relax the orthonormality restriction on the orbital basis and break down the originally very large calculations into a series of smaller calculations that can be run in parallel. Each calculation determines a partitioned correlation function (PCF) that accounts for a specific correlation effect. The PCFs are built on optimally localized orbital sets and are added to a zero-order multireference (MR) function to form a total wave function. The expansion coefficients of the PCFs are determined from a low dimensional generalized eigenvalue problem. The interaction and overlap matrices are computed using a biorthonormal transformation technique (Verdebout et al 2010 J. Phys. B: At. Mol. Phys. 43 074017). The new method, called partitioned correlation function interaction (PCFI), converges rapidly with respect to the orbital basis and gives total energies that are lower than the ones from ordinary MCHF and CI calculations. The PCFI method is also very flexible when it comes to targeting different electron correlation effects. Focusing our attention on neutral lithium, we show that by dedicating a PCF to the single excitations from the core, spin- and orbital-polarization effects can be captured very efficiently, leading to highly improved convergence patterns for hyperfine parameters compared with MCHF calculations based on a single orthogonal radial orbital basis. By collecting separately optimized PCFs to correct the
A partitioned correlation function interaction approach for describing electron correlation in atoms
Verdebout, S.; Rynkun, P.; Jönsson, P.; Gaigalas, G.; Froese Fischer, C.; Godefroid, M.
2013-04-01
The traditional multiconfiguration Hartree-Fock (MCHF) and configuration interaction (CI) methods are based on a single orthonormal orbital basis. For atoms with many closed core shells, or complicated shell structures, a large orbital basis is needed to saturate the different electron correlation effects such as valence, core-valence and correlation within the core shells. The large orbital basis leads to massive configuration state function (CSF) expansions that are difficult to handle, even on large computer systems. We show that it is possible to relax the orthonormality restriction on the orbital basis and break down the originally very large calculations into a series of smaller calculations that can be run in parallel. Each calculation determines a partitioned correlation function (PCF) that accounts for a specific correlation effect. The PCFs are built on optimally localized orbital sets and are added to a zero-order multireference (MR) function to form a total wave function. The expansion coefficients of the PCFs are determined from a low dimensional generalized eigenvalue problem. The interaction and overlap matrices are computed using a biorthonormal transformation technique (Verdebout et al 2010 J. Phys. B: At. Mol. Phys. 43 074017). The new method, called partitioned correlation function interaction (PCFI), converges rapidly with respect to the orbital basis and gives total energies that are lower than the ones from ordinary MCHF and CI calculations. The PCFI method is also very flexible when it comes to targeting different electron correlation effects. Focusing our attention on neutral lithium, we show that by dedicating a PCF to the single excitations from the core, spin- and orbital-polarization effects can be captured very efficiently, leading to highly improved convergence patterns for hyperfine parameters compared with MCHF calculations based on a single orthogonal radial orbital basis. By collecting separately optimized PCFs to correct the MR
Heavy particle signatures in cosmological correlation functions with tensor modes
Saito, Ryo; Kubota, Takahiro
2018-06-01
We explore the possibility to make use of cosmological data to look for signatures of unknown heavy particles whose masses are on the order of the Hubble parameter during the time of inflation. To be more specific we take up the quasi-single field inflation model, in which the isocurvaton σ is supposed to be the heavy particle. We study correlation functions involving both scalar (ζ ) and tensor (γ ) perturbations and search for imprints of the σ-particle effects. We make use of the technique of the effective field theory for inflation to derive the ζ σ and γ ζ σ couplings. With these couplings we compute the effects due to σ to the power spectrum langle ζ ζ rangle and correlations langle γs ζ ζ rangle and langle γs1 γ s2 ζ ζ rangle , where s, s1 and s2 are the polarization indices of gravitons. Numerical analyses of the σ-mass effects to these correlations are presented. It is argued that future precise observations of these correlations could make it possible to measure the σ-mass and the strength of the ζ σ and γ ζ σ couplings. As an extension to the N-graviton case we also compute the correlations langle γ s1 ... γ sN ζ ζ rangle and langle γ s1 ... ... γ s2N ζ ζ rangle and their σ-mass effects. It is suggested that larger N correlation functions are useful to probe larger σ-mass.
Spectroscopy of pseudoscalar and vector mesons and their electroweak decays
Ablakulov, Kh.
1997-01-01
Proceeding from the effective action of QCD for bilocal meson fields the formula for the action describing the spectroscopy of mesons and their electroweak decays is obtained. The numerical solutions of the Salpeter equation (SE) for the qq-bound state and the Schwinger-Dyson equation (SDE) for the quark phase function are obtained with potential as sum of the oscillator and Coulomb terms. It is shown that for the oscillator potential and current quark mass m 0 0 → γγ) are 3-4 times smaller than their experimentations. This discrepancy was not removed even choosing other shapes of the potential. In order to resolve this problem the modification of the SDE, which consists in introducing the additional terms that do not change asymptotical properties of solutions of this equation is proposed. Using such modification both constant fπ and Γ(π 0 → γγ) are reproduced on a good quantitative level. The new SE for vector mesons is proposed and its solution with potential mentioned above gives the mass spectra of these mesons. Considering the τ → ρν decay the representation for leptonic decay constant of ρ meson f π , which expresses via solutions of the SDE and the proposed SE with a given potential is obtained. It is shown that the proposed SE allows to describe both the spectroscopy of vector mesons and their leptonic decay constants on a satisfactory level in comparison with the experimental values. (author)
Two-body correlation functions in dilute nuclear matter
Isayev, A A
2006-01-01
Finding the distinct features of the crossover from the regime of large overlapping Cooper pairs to the limit of non-overlapping pairs of fermions (Shafroth pairs) in multicomponent Fermi systems remains one of the actual problems in a quantum many-body theory. Here this transition is studied by calculating the two-body density, spin and isospin correlation functions in dilute asymmetric nuclear matter. It is shown that criterion of the crossover (Phys. Rev. Lett. 95, 090402 (2005)), consisting in the change of the sign of the density correlation function at low momentum transfer, fails to describe correctly the density-driven BEC-BCS transition at finite isospin asymmetry or finite temperature. As an unambiguous signature of the BEC-BCS transition, there can be used the presence (BCS regime) or absence (BEC regime) of the singularity in the momentum distribution of the quasiparticle density of states
Decay of random correlation functions for unimodal maps
Baladi, Viviane; Benedicks, Michael; Maume-Deschamps, Véronique
2000-10-01
Since the pioneering results of Jakobson and subsequent work by Benedicks-Carleson and others, it is known that quadratic maps tfa( χ) = a - χ2 admit a unique absolutely continuous invariant measure for a positive measure set of parameters a. For topologically mixing tfa, Young and Keller-Nowicki independently proved exponential decay of correlation functions for this a.c.i.m. and smooth observables. We consider random compositions of small perturbations tf + ωt, with tf = tfa or another unimodal map satisfying certain nonuniform hyperbolicity axioms, and ωt chosen independently and identically in [-ɛ, ɛ]. Baladi-Viana showed exponential mixing of the associated Markov chain, i.e., averaging over all random itineraries. We obtain stretched exponential bounds for the random correlation functions of Lipschitz observables for the sample measure μωof almost every itinerary.
Temporal correlation functions of concentration fluctuations: an anomalous case.
Lubelski, Ariel; Klafter, Joseph
2008-10-09
We calculate, within the framework of the continuous time random walk (CTRW) model, multiparticle temporal correlation functions of concentration fluctuations (CCF) in systems that display anomalous subdiffusion. The subdiffusion stems from the nonstationary nature of the CTRW waiting times, which also lead to aging and ergodicity breaking. Due to aging, a system of diffusing particles tends to slow down as time progresses, and therefore, the temporal correlation functions strongly depend on the initial time of measurement. As a consequence, time averages of the CCF differ from ensemble averages, displaying therefore ergodicity breaking. We provide a simple example that demonstrates the difference between these two averages, a difference that might be amenable to experimental tests. We focus on the case of ensemble averaging and assume that the preparation time of the system coincides with the starting time of the measurement. Our analytical calculations are supported by computer simulations based on the CTRW model.
Finite-size effects on current correlation functions
Chen, Shunda; Zhang, Yong; Wang, Jiao; Zhao, Hong
2014-02-01
We study why the calculation of current correlation functions (CCFs) still suffers from finite-size effects even when the periodic boundary condition is taken. Two important one-dimensional, momentum-conserving systems are investigated as examples. Intriguingly, it is found that the state of a system recurs in the sense of microcanonical ensemble average, and such recurrence may result in oscillations in CCFs. Meanwhile, we find that the sound mode collisions induce an extra time decay in a current so that its correlation function decays faster (slower) in a smaller (larger) system. Based on these two unveiled mechanisms, a procedure for correctly evaluating the decay rate of a CCF is proposed, with which our analysis suggests that the global energy CCF decays as ˜t-2/3 in the diatomic hard-core gas model and in a manner close to ˜t-1/2 in the Fermi-Pasta-Ulam-β model.
Total Correlation Function Integrals and Isothermal Compressibilities from Molecular Simulations
Wedberg, Rasmus; Peters, Günther H.j.; Abildskov, Jens
2008-01-01
Generation of thermodynamic data, here compressed liquid density and isothermal compressibility data, using molecular dynamics simulations is investigated. Five normal alkane systems are simulated at three different state points. We compare two main approaches to isothermal compressibilities: (1...... in approximately the same amount of time. This suggests that computation of total correlation function integrals is a route to isothermal compressibility, as accurate and fast as well-established benchmark techniques. A crucial step is the integration of the radial distribution function. To obtain sensible results...
CCFpams: Atmospheric stellar parameters from cross-correlation functions
Malavolta, Luca; Lovis, Christophe; Pepe, Francesco; Sneden, Christopher; Udry, Stephane
2017-07-01
CCFpams allows the measurement of stellar temperature, metallicity and gravity within a few seconds and in a completely automated fashion. Rather than performing comparisons with spectral libraries, the technique is based on the determination of several cross-correlation functions (CCFs) obtained by including spectral features with different sensitivity to the photospheric parameters. Literature stellar parameters of high signal-to-noise (SNR) and high-resolution HARPS spectra of FGK Main Sequence stars are used to calibrate the stellar parameters as a function of CCF areas.
Meson 2000 Conference Summary lite
Barnes, T.
2000-01-01
This short contribution is a late MESON2000 conference summary. As appropriate for the 600th anniversary of the Jagiellonian University, it begins with a brief summary of the last 600 years of European history and its place in hadron physics. Next a ''physicist chirality'' order parameter PC is introduced. When applied to MESON2000 plenary speakers this order parameter illustrates the separation of hadron physicists into disjoint communities. The individual plenary talks in MESON2000 are next sorted according to the subconference associated with each of the 36 plenary speakers. Finally, I conclude with a previously unreported Feynman story regarding the use of models in hadron physics. (author)
Hard electroproduction of hybrid mesons
Anikin, I.V.; LPT Universite Paris-Sud, Orsay; Szymanowski, L.; Teryaev, O.V.; ); Wallon, S.
2005-01-01
We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC = 1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e. as 1/Q 2 . This is due to the non-vanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in as and we explore the consequences of fixing the renormalization scale ambiguity through the BLM procedure. (author)
Quantum electrodynamics and light rays. [Two-point correlation functions
Sudarshan, E.C.G.
1978-11-01
Light is a quantum electrodynamic entity and hence bundles of rays must be describable in this framework. The duality in the description of elementary optical phenomena is demonstrated in terms of two-point correlation functions and in terms of collections of light rays. The generalizations necessary to deal with two-slit interference and diffraction by a rectangular slit are worked out and the usefulness of the notion of rays of darkness illustrated. 10 references.
Charmonium correlators and spectral functions at finite temperature
Ding,H.T.; Kaczmarek, O.; Karsch, F.; Satz, H.
2008-09-01
We present an operational approach to address the in-medium behavior of charmonium and analyze the reliability of maximum entropy method (MEM). We study the dependences of the ratio of correlators to the reconstructed one and the free one on the resonance's width and the continuum's threshold. Furthermore, we discuss the issue of the default model dependence of the spectral function obtained from MEM.
Correlation functions of one-dimensional bosons at low temperature
Kozlowski, K.K. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Maillet, J.M. [CNRS, ENS Lyon (France). Lab. de Physique; Slavnov, N.A. [Steklov Mathematical Institute, Moscow (Russian Federation)
2010-12-15
We consider the low-temperature limit of the long-distance asymptotic behavior of the finite temperature density-density correlation function in the one-dimensional Bose gas derived recently in the algebraic Bethe Ansatz framework. Our results confirm the predictions based on the Luttinger liquid and conformal field theory approaches. We also demonstrate that the amplitudes arising in this asymptotic expansion at low-temperature coincide with the amplitudes associated with the so-called critical form factors. (orig.)
On Soft Limits of Large-Scale Structure Correlation Functions
Ben-Dayan, Ido; Konstandin, Thomas; Porto, Rafael A.; Sagunski, Laura
2014-01-01
We study soft limits of correlation functions for the density and velocity fields in the theory of structure formation. First, we re-derive the (resummed) consistency conditions at unequal times using the eikonal approximation. These are solely based on symmetry arguments and are therefore universal. Then, we explore the existence of equal-time relations in the soft limit which, on the other hand, depend on the interplay between soft and hard modes. We scrutinize two approaches in the literat...
An improved method for estimating the frequency correlation function
Chelli, Ali; Pä tzold, Matthias
2012-01-01
For time-invariant frequency-selective channels, the transfer function is a superposition of waves having different propagation delays and path gains. In order to estimate the frequency correlation function (FCF) of such channels, the frequency averaging technique can be utilized. The obtained FCF can be expressed as a sum of auto-terms (ATs) and cross-terms (CTs). The ATs are caused by the autocorrelation of individual path components. The CTs are due to the cross-correlation of different path components. These CTs have no physical meaning and leads to an estimation error. We propose a new estimation method aiming to improve the estimation accuracy of the FCF of a band-limited transfer function. The basic idea behind the proposed method is to introduce a kernel function aiming to reduce the CT effect, while preserving the ATs. In this way, we can improve the estimation of the FCF. The performance of the proposed method and the frequency averaging technique is analyzed using a synthetically generated transfer function. We show that the proposed method is more accurate than the frequency averaging technique. The accurate estimation of the FCF is crucial for the system design. In fact, we can determine the coherence bandwidth from the FCF. The exact knowledge of the coherence bandwidth is beneficial in both the design as well as optimization of frequency interleaving and pilot arrangement schemes. © 2012 IEEE.
An improved method for estimating the frequency correlation function
Chelli, Ali
2012-04-01
For time-invariant frequency-selective channels, the transfer function is a superposition of waves having different propagation delays and path gains. In order to estimate the frequency correlation function (FCF) of such channels, the frequency averaging technique can be utilized. The obtained FCF can be expressed as a sum of auto-terms (ATs) and cross-terms (CTs). The ATs are caused by the autocorrelation of individual path components. The CTs are due to the cross-correlation of different path components. These CTs have no physical meaning and leads to an estimation error. We propose a new estimation method aiming to improve the estimation accuracy of the FCF of a band-limited transfer function. The basic idea behind the proposed method is to introduce a kernel function aiming to reduce the CT effect, while preserving the ATs. In this way, we can improve the estimation of the FCF. The performance of the proposed method and the frequency averaging technique is analyzed using a synthetically generated transfer function. We show that the proposed method is more accurate than the frequency averaging technique. The accurate estimation of the FCF is crucial for the system design. In fact, we can determine the coherence bandwidth from the FCF. The exact knowledge of the coherence bandwidth is beneficial in both the design as well as optimization of frequency interleaving and pilot arrangement schemes. © 2012 IEEE.
Statistical Study of Turbulence: Spectral Functions and Correlation Coefficients
Frenkiel, Francois N.
1958-01-01
In reading the publications on turbulence of different authors, one often runs the risk of confusing the various correlation coefficients and turbulence spectra. We have made a point of defining, by appropriate concepts, the differences which exist between these functions. Besides, we introduce in the symbols a few new characteristics of turbulence. In the first chapter, we study some relations between the correlation coefficients and the different turbulence spectra. Certain relations are given by means of demonstrations which could be called intuitive rather than mathematical. In this way we demonstrate that the correlation coefficients between the simultaneous turbulent velocities at two points are identical, whether studied in Lagrange's or in Euler's systems. We then consider new spectra of turbulence, obtained by study of the simultaneous velocities along a straight line of given direction. We determine some relations between these spectra and the correlation coefficients. Examining the relation between the spectrum of the turbulence measured at a fixed point and the longitudinal-correlation curve given by G. I. Taylor, we find that this equation is exact only when the coefficient is very small.
Effective meson lagrangian with chiral and heavy quark symmetries from quark flavor dynamics
Ebert, D.; Feldmann, T.; Friedrich, R.; Reinhardt, H.
1994-06-01
By bosonization of an extended NJL model we derive an effective meson theory which describes the interplay between chiral symmetry and heavy quark dynamics. This effective theory is worked out in the low-energy regime using the gradient expansion. The resulting effective lagrangian describes strong and weak interactions of heavy B and D mesons with pseudoscalar Goldstone bosons and light vector and axial-vector mesons. Heavy meson weak decay constants, coupling constants and the Isgur-Wise function are predicted in terms of the model parameters partially fixed from the light quark sector. Explicit SU(3) F symmetry breaking effects are estimated and, if possible, confronted with experiment. (orig.)
Local-duality QCD sum rules for strong isospin breaking in the decay constants of heavy-light mesons
Lucha, Wolfgang [Austrian Academy of Sciences, Institute for High Energy Physics, Vienna (Austria); Melikhov, Dmitri [Austrian Academy of Sciences, Institute for High Energy Physics, Vienna (Austria); M.V. Lomonosov Moscow State University, D.V. Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); University of Vienna, Faculty of Physics, Vienna (Austria); Simula, Silvano [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tre, Rome (Italy)
2018-02-15
We discuss the leptonic decay constants of heavy-light mesons by means of Borel QCD sum rules in the local-duality (LD) limit of infinitely large Borel mass parameter. In this limit, for an appropriate choice of the invariant structures in the QCD correlation functions, all vacuum-condensate contributions vanish and all nonperturbative effects are contained in only one quantity, the effective threshold. We study properties of the LD effective thresholds in the limits of large heavy-quark mass m{sub Q} and small light-quark mass m{sub q}. In the heavy-quark limit, we clarify the role played by the radiative corrections in the effective threshold for reproducing the pQCD expansion of the decay constants of pseudoscalar and vector mesons. We show that the dependence of the meson decay constants on m{sub q} arises predominantly (at the level of 70-80%) from the calculable m{sub q}-dependence of the perturbative spectral densities. Making use of the lattice QCD results for the decay constants of nonstrange and strange pseudoscalar and vector heavy mesons, we obtain solid predictions for the decay constants of heavy-light mesons as functions of m{sub q} in the range from a few to 100 MeV and evaluate the corresponding strong isospin-breaking effects: f{sub D{sup +}} - f{sub D{sup 0}} = (0.96 ± 0.09) MeV, f{sub D}{sup {sub *}{sub +}} - f{sub D}{sup {sub *}{sub 0}} = (1.18 ± 0.35) MeV, f{sub B{sup 0}} - f{sub B{sup +}} = (1.01 ± 0.10) MeV, f{sub B}{sup {sub *}{sub 0}} - f{sub B}{sup {sub *}{sub +}} = (0.89 ± 0.30) MeV. (orig.)
Haas, F.
2009-01-01
In addition to constituent q q(bar) pair configurations, four quark states or gluonic excitations like hybrids or glueballs are also expected to contribute to the mesonic spectrum. The most promising way to identify such states allowed by QCD is the search for J PC quantum number combinations which are forbidden in the constituent quark model. The fixed target COMPASS experiment at CERN offers the opportunity to search for such states in the light quark sector with an unprecedented statistics. First studies of diffractive reactions of 190 GeV/c ions were carried out by COMPASS during a pilot run in 2004. In a first analysis, the three charged pion final state was studied. A Partial Wave Analysis (PWA) with 42 waves including acceptance corrections through a phase-space Monte Carlo simulation of the spectrometer was performed. The exotic π1 (1600) meson with quantum numbers J PC 1 -+ has been clearly established in the ρ-π decay channel with a mass of 1660 ± 0.010(stat) MeV and a width of 0.269 ± 0.021(stat) MeV. The final state with 5 charged pions was also investigated. Results from that study will also be presented. The improved detectors performance in 2008 allows us to study besides these channels further diffractively and centrally produced resonances, neutral ones as well as charged ones. First results of the ongoing analysis of the 2008 data taking period, using a 190 GeV/c pion beam on a hydrogen target will be given. (author)
Two-proton correlation functions in nuclear reactions
Verde, G.
2001-01-01
Full text: Proton-proton correlation functions can be used to study the space-time characteristics of nuclear reactions. For very short-lived sources, the maximum value of the correlation at 20 MeV/c, due to the attractive nature of the S-wave phase shift, provides a unique measure of the size of the emitting source. For long-lived sources, the height of this maximum depends, in addition, on the life time of the source. In this talk, we investigate the common reaction scenario involving both fast dynamical as well as slower emissions from evaporation and/or secondary decays of heavy fragments. We show that the maximum at 20 MeV/c depends both on the source dimension and on the fraction of coincident proton pairs produced in the early stage of the reaction, dominated by fast dynamical preequilibrium emission. The width of the peak at 20 MeV/c, on the other hand, is uniquely correlated to the size of the source. Hence, the size of the emitting source must be extracted from the width or, even better, from the entire shape of the correlation peak, and not from the height. By numerically inverting the measured correlation function, we show that existing data determine only the shape of the fast dynamical source and that its size changes little with proton momenta, contrary to previous analyses with Gaussian sources of zero-lifetime. We further show that the well documented dramatic decrease in the correlation maximum with decreasing total proton momentum reflects directly a corresponding decrease in the fraction of contributing proton pairs from preequilibrium emissions. This provides a powerful method to decompose the proton spectrum into a fraction that originates from fast dynamical emission and a complimentary fraction that originates from slower evaporative emission or secondary decays. We discuss also the comparison of such correlations to transport theories and the generalizations of these techniques to correlations between composite particles. Such studies can
Correlates of cognitive function scores in elderly outpatients.
Mangione, C M; Seddon, J M; Cook, E F; Krug, J H; Sahagian, C R; Campion, E W; Glynn, R J
1993-05-01
To determine medical, ophthalmologic, and demographic predictors of cognitive function scores as measured by the Telephone Interview for Cognitive Status (TICS), an adaptation of the Folstein Mini-Mental Status Exam. A secondary objective was to perform an item-by-item analysis of the TICS scores to determine which items correlated most highly with the overall scores. Cross-sectional cohort study. The Glaucoma Consultation Service of the Massachusetts Eye and Ear Infirmary. 472 of 565 consecutive patients age 65 and older who were seen at the Glaucoma Consultation Service between November 1, 1987 and October 31, 1988. Each subject had a standard visual examination and review of medical history at entry, followed by a telephone interview that collected information on demographic characteristics, cognitive status, health status, accidents, falls, symptoms of depression, and alcohol intake. A multivariate linear regression model of correlates of TICS score found the strongest correlates to be education, age, occupation, and the presence of depressive symptoms. The only significant ocular condition that correlated with lower TICS score was the presence of surgical aphakia (model R2 = .46). Forty-six percent (216/472) of patients fell below the established definition of normal on the mental status scale. In a logistic regression analysis, the strongest correlates of an abnormal cognitive function score were age, diabetes, educational status, and occupational status. An item analysis using step-wise linear regression showed that 85 percent of the variance in the TICS score was explained by the ability to perform serial sevens and to repeat 10 items immediately after hearing them. Educational status correlated most highly with both of these items (Kendall Tau R = .43 and Kendall Tau R = .30, respectively). Education, occupation, depression, and age were the strongest correlates of the score on this new screening test for assessing cognitive status. These factors were
Lange, Adrian; Stinchcombe, Robin [Theoretical Physics, University of Oxford, Oxford (United Kingdom)
1996-07-07
We study the general behaviour of the correlation length {zeta}(kT:h) for two-point correlation function of the local fields in an Ising chain with binary distributed fields. At zero field it is shown that {zeta} is the same as the zero-field correlation length for the spin-spin correlation function. For the field-dominated behaviour of {zeta} we find an exponent for the power-law divergence which is smaller than the exponent for the spin-spin correlation length. The entire behaviour of the correlation length can be described by a single crossover scaling function involving the new critical exponent. (author)
Brookhaven: Hunting for unusual mesons
Dzierba, Alex R.
1990-12-15
After the overwhelming experimental evidence for the quark model came the notions of colour and confinement which explained why quarks should prefer to bind in 'colourless' systems - quark-antiquark (mesons) and three quarks (baryons)
Brookhaven: Hunting for unusual mesons
Dzierba, Alex R.
1990-01-01
After the overwhelming experimental evidence for the quark model came the notions of colour and confinement which explained why quarks should prefer to bind in 'colourless' systems - quark-antiquark (mesons) and three quarks (baryons)
Fast methods for spatially correlated multilevel functional data
Staicu, A.-M.
2010-01-19
We propose a new methodological framework for the analysis of hierarchical functional data when the functions at the lowest level of the hierarchy are correlated. For small data sets, our methodology leads to a computational algorithm that is orders of magnitude more efficient than its closest competitor (seconds versus hours). For large data sets, our algorithm remains fast and has no current competitors. Thus, in contrast to published methods, we can now conduct routine simulations, leave-one-out analyses, and nonparametric bootstrap sampling. Our methods are inspired by and applied to data obtained from a state-of-the-art colon carcinogenesis scientific experiment. However, our models are general and will be relevant to many new data sets where the object of inference are functions or images that remain dependent even after conditioning on the subject on which they are measured. Supplementary materials are available at Biostatistics online.
Reduced density-matrix functional theory: Correlation and spectroscopy.
Di Sabatino, S; Berger, J A; Reining, L; Romaniello, P
2015-07-14
In this work, we explore the performance of approximations to electron correlation in reduced density-matrix functional theory (RDMFT) and of approximations to the observables calculated within this theory. Our analysis focuses on the calculation of total energies, occupation numbers, removal/addition energies, and spectral functions. We use the exactly solvable Hubbard dimer at 1/4 and 1/2 fillings as test systems. This allows us to analyze the underlying physics and to elucidate the origin of the observed trends. For comparison, we also report the results of the GW approximation, where the self-energy functional is approximated, but no further hypothesis is made concerning the approximations of the observables. In particular, we focus on the atomic limit, where the two sites of the dimer are pulled apart and electrons localize on either site with equal probability, unless a small perturbation is present: this is the regime of strong electron correlation. In this limit, using the Hubbard dimer at 1/2 filling with or without a spin-symmetry-broken ground state allows us to explore how degeneracies and spin-symmetry breaking are treated in RDMFT. We find that, within the used approximations, neither in RDMFT nor in GW, the signature of strong correlation is present, when looking at the removal/addition energies and spectral function from the spin-singlet ground state, whereas both give the exact result for the spin-symmetry broken case. Moreover, we show how the spectroscopic properties change from one spin structure to the other.
Anon.
1992-05-15
Using a nuclear reaction, the new tagged eta meson facility now operating at the French Saturne National Laboratory in Saclay produces eta mesons (together with recoil helium-3 nuclei) by proton bombardment of a deuterium target. The proton beam is extracted from the Saturne synchrotron at 893 MeV, stabilized to 80 keV. This is a scant 1.5 MeV above the reaction threshold and close to the energy where eta production peaks.
Anon.
1992-01-01
Using a nuclear reaction, the new tagged eta meson facility now operating at the French Saturne National Laboratory in Saclay produces eta mesons (together with recoil helium-3 nuclei) by proton bombardment of a deuterium target. The proton beam is extracted from the Saturne synchrotron at 893 MeV, stabilized to 80 keV. This is a scant 1.5 MeV above the reaction threshold and close to the energy where eta production peaks
Vector mesons in reactions with colliding electron-positron beams
Rekalo, M.P.; Gakh, G.I.
1980-01-01
Polarization phenomena in the processes of vector meson production in reactions with colliding electron-positron beams e + e - → V+X, where V is a vector meson, X is a nondetected set of particles are investigated. For the one-photon mechanism of the process, where V and X are hadrons, the mutually unambiguous correspondence between the structural functions is found. The dependence of the e + e - → VX differential cross section upon the electron and positron polarizations is calculated using the virtual photon density matrix in the helicity basis. This formalism permits to take explicitly into account the P-invariance consequences for the angular distribution of the V-meson decay products. For the processes e + e - → πA 1 , and e + e - → rho + rho - the structural functions are calculated in terms of the corresponding electromagnetic form factors. It is noted that six functions out ten real structural functions describing the e + e - → VX reaction can be determined by means of investigation of the angular distribution of the V-meson decay products which is produced in collisions of unpolarized leptons. To study the collision of polarized leptons one more structural function can be determined. The formation of the X system with definite values of parity and spin is characterized by seven structural functions, five of which can be found while studying the angular distribution of the V-meson decay products produced in e + e - collisions with unpolarized (polarized) particles. If the spin of the X state is 1, in experiments with polarized beams all structural functions can be determined while investigating the angular distribution of the V-meson decay products
Approximate models for the analysis of laser velocimetry correlation functions
Robinson, D.P.
1981-01-01
Velocity distributions in the subchannels of an eleven pin test section representing a slice through a Fast Reactor sub-assembly were measured with a dual beam laser velocimeter system using a Malvern K 7023 digital photon correlator for signal processing. Two techniques were used for data reduction of the correlation function to obtain velocity and turbulence values. Whilst both techniques were in excellent agreement on the velocity, marked discrepancies were apparent in the turbulence levels. As a consequence of this the turbulence data were not reported. Subsequent investigation has shown that the approximate technique used as the basis of Malvern's Data Processor 7023V is restricted in its range of application. In this note alternative approximate models are described and evaluated. The objective of this investigation was to develop an approximate model which could be used for on-line determination of the turbulence level. (author)
Properties of rho and eta mesons in nuclear matter
Herrmann, M.; Sauermann, C.; Friman, B.L.; Technische Hochschule Darmstadt; Noerenberg, W.; Technische Hochschule Darmstadt
1993-10-01
The properties of ρ- and η-mesons in nuclear matter are studied within the scope of hadronic models. Unknown model parameters are obtained from fits to scattering data. - The treatment of the ρ-meson includes the coupling to two pions which, in matter, are strongly mixed with delta-particle-nucleon-hole states. The ρ-meson self-energy is evaluated in a current conserving approximation with in-medium pion propagators and vertex corrections. While the position of the original peak in the spectral function remains almost unchanged, its width grows rapidly with increasing density. Consequently, the ρ-meson strength function is strongly dispersed at high densities. Due to vertex corrections a new peak at a mass around 3m π emerges with increasing density, while the spectral function around the two-pion threshold is found to be smooth at all densities. The η-meson is strongly mixed with N * (1535)-particle-nucleon-hole states in nuclear matter. The corresponding dispersion relations with an upper and a lower branch look similar to those of the (π, ΔN -1 )-modes. However, since the N * is an S-wave resonance in the ηN-channel, the repulsion of the two branches survives at zero momentum. (orig.)
Vector meson production in the final state K K of photon-photon collisions
Althoff, M; Braunschweig, W; Gerhards, R; Kirschfink, J F; Martyn, H U; Rosskamp, P; Wallraff, W; Bock, B; Eisenmann, Y; Fischer, H M
1986-08-01
Vector meson production is studied in the reaction ->K K . A clear PHI(1020) signal is seen in the K K mass distribution and a Ksup(*0)(890) signal is visible in the Ksup(+-) sup(-+) one. Both do not seem to be strongly correlated with quasi two body final states. Cross sections for the processes ->K K , ->PHI , ->Ksup(*0)Ksup(+-) sup(-+) and upper limits for the production of duction of PHIrho, PHIPHI and Ksup(*0)Ksup(*0) are given as function of the invariant mass.
Vector meson production in the final state K+K-π+π- photon-photon collisions
ALthoff, M.; Braunschweig, W.; Gerhards, R.; Kirschfink, J.F.; Martyn, H.U.; Rosskamp, P.; Wallraff, W.; Bowler, M.G.; Bull, P.; Cashmore, R.J.; Dauncey, P.; Devenish, R.; Heath, G.; Mellor, D.J.; Ratoff, P.; Baranko, G.; Caldwell, A.; Cherney, M.; Izen, J.M.; Ritz, S.; Strom, D.; Takashima, M.; Wicklund, E.; Wu Saulan; Zobernig, G.; Bernardi, E.; Eisenberg, Y.; Eskresy, A.; Gather, K.; Hultschig, H.; Joos, P.; Klima, B.; Kowalski, H.; Ladage, A.; Loehr, B.; Maettig, P.; Notz, D.; Revel, D.; Ronat, E.; Trines, D.; Tymieniecka, R.; Walcak, R.; Wolf, G.; Zeuner, W.S.
1986-03-01
Vector meson production is studied in the reaction γγ -> K + K - π + π - . A clear PHI(1020) signal is seen in the K + K - mass distribution and a Ksup(*0)(890) signal is visible in the Ksup(+-)πsup(-+) one. Both do not seem to be strongly correlated with quasi two body final states. Cross sections for the processes γγ -> K + K - π + π - , γγ -> PHIπ + π - , γγ -> Ksup(*0)Ksup(+-)πsup(-+) and upper limits for the production of PHIrho, PHIPHI and Ksup(*0)Ksup(*0) are given as function of the invariant γγ mass. (orig.)
The ion-electron correlation function in liquid metals
Takeda, S.; Tamaki, S.; Waseda, Y.
1985-01-01
The structure factors of liquid Zn at 723 K, Sn at 523 K and Bi at 573 K have been determined by neutron diffraction with sufficient accuracy and compared with those of X-ray diffraction. A remarkable difference in the structural information between the two methods is clearly found around the first peak region as well as in the slightly varied peak positions, and it is apparently larger than the experimental errors. With these facts in mind, a new method evaluating the ion-electron correlation function in liquid metals has been proposed by using the measured structural data of X-rays and neutrons, with the help of theoretical values of the electron-electron correlation function by he Utsumi-Ichimaru scheme. This method has been applied to liquid Zn, Sn and Bi, and the radial distribution function of valence electrons around an ion has been estimated, from which the ionic radius and the schematic diagram of the electron distribution map are obtained. The ionic radii evaluated in this work have been found to agree well with those proposed by Pauling. (author)
Properties of the ρ meson in dense nuclear matter
Herrmann, M.
1992-05-01
In order to reach a description of the ρ meson, which is in accordance with the principles of the gauge invariance of the electromagnetic interaction, the vector-dominance hypothesis, and the unitarity a model for the ρ meson in the vacuum is developed. Thereafter follows the calculation of the properties of the ρ meson in nuclear matter. First the connection between the spectral function of the ρ meson and the dilepton production rate for an equilibrium state is derived. Then the model for the pion in nuclear matter is described. Following approximations are applied: The description of the pion-baryon interaction pursues non-relativistically and both the width of the delta resonance and the short-range repulsive delta-nucleon interaction is neglected. The self-energy of the ρ meson in nuclear matter following from this description is formally derived from the requirement to couple the ρ meson to a conserved current. The corrections for the 3-point and 4-point vertex resulting from this are calculated and discussed. Thereafter the physical consequences of the changed self-energy of the ρ meson in nuclear matter are considered. By means of the spectral function it is shown that up to the two-fold of the ground-state density the position of the resonance is nearly not changed. At still higher densities the resonances is a little shifted to higher energies. In the range of an invariant mass of about 400 meV a strong increasement concentrated on a small range results. This is caused by coupling to a naked delta-hole state and a pion. Finally the possibilities are discussed to apply the results of this thesis to the prediction of experimental data. Thereby it is proved to be necessary to base on a simulation of the heavy ion reaction. (orig./HSI) [de
Mixed meson masses with domain-wall valence and staggered sea fermions
Orginos, Kostas; Walker-Loud, Andre
2008-01-01
Mixed action lattice calculations allow for an additive lattice-spacing-dependent mass renormalization of mesons composed of one sea and one valence quark, regardless of the type of fermion discretization methods used in the valence and sea sectors. The value of the mass renormalization depends upon the lattice actions used. This mixed meson mass shift is an important lattice artifact to determine for mixed action calculations; because it modifies the pion mass, it plays a central role in the low-energy dynamics of all hadronic correlation functions. We determine the leading order, O(a 2 ), and next-to-leading order, O(a 2 m π 2 ), additive mass shift of valence-sea mesons for a mixed lattice action with domain-wall valence fermions and rooted staggered sea fermions, relevant to the majority of current large scale mixed action lattice efforts. We find that, on the asqtad-improved coarse MILC lattices, this additive mass shift is well parametrized in lattice units by Δ(am) 2 =0.034(2)-0.06(2)(am π ) 2 , which in physical units, using a=0.125 fm, corresponds to Δ(m) 2 =(291±8 MeV) 2 -0.06(2)m π 2 . In terms of the mixed action effective field theory parameters, the corresponding mass shift is given by a 2 Δ Mix =(316±4 MeV) 2 at leading order plus next-to-leading order corrections including the necessary chiral logarithms for this mixed action calculation, determined in this work. Within the precision of our calculation, one cannot distinguish between the full next-to-leading order effective field theory analysis of this additive mixed meson mass shift and the parametrization given above.
Pan, Feng; Tao, Guohua
2013-03-07
Full semiclassical (SC) initial value representation (IVR) for time correlation functions involves a double phase space average over a set of two phase points, each of which evolves along a classical path. Conventionally, the two initial phase points are sampled independently for all degrees of freedom (DOF) in the Monte Carlo procedure. Here, we present an efficient importance sampling scheme by including the path correlation between the two initial phase points for the bath DOF, which greatly improves the performance of the SC-IVR calculations for large molecular systems. Satisfactory convergence in the study of quantum coherence in vibrational relaxation has been achieved for a benchmark system-bath model with up to 21 DOF.
The charge form factor of pseudoscalar mesons in a relativistic constituent quark model
Cardarelli, F.; Pace, E. [Univ. of Rome, Roma (Italy); Grach, I.L. [Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation)] [and others
1994-04-01
The charge form factor of pseudoscalar mesons has been investigated in the light-cone formalism, up to Q{sup 2} relevant to CEBAF energies. The consequences of adopting the meson wave functions generated through the Godfrey-Isgur q{bar q} potential, which reproduces the mass spectra, are discussed.
Time-dependent friction and solvation time correlation function
Samanta, Alok; Ali, Sk Musharaf; Ghosh, Swapan K
2005-01-01
We have derived a new relation between the time-dependent friction and solvation time correlation function (STCF) for non-polar fluids. The friction values calculated using this relation and simulation results on STCF for a Lennard-Jones fluid are shown to have excellent agreement with the same obtained through mode-coupling theory. Also derived is a relation between the time-dependent dielectric friction and STCF for polar fluids. Routes are thus provided to obtain the time-dependent friction (non-polar as well as dielectric) from an experimentally measured quantity like STCF, even if the interparticle interaction potential is not known
Yang-Mills correlation functions from integrable spin chains
Roiban, Radu; Volovich, Anastasia
2004-01-01
The relation between the dilatation operator of N = 4 Yang-Mills theory and integrable spin chains makes it possible to compute the one-loop anomalous dimensions of all operators in the theory. In this paper we show how to apply the technology of integrable spin chains to the calculation of Yang-Mills correlation functions by expressing them in terms of matrix elements of spin operators on the corresponding spin chain. We illustrate this method with several examples in the SU(2) sector described by the XXX 1/2 chain. (author)
Green's functions for off-shell electromagnetism and spacelike correlations
Land, M.C.; Horwitz, L.P.
1991-01-01
The requirement of gauge invariance for the Schwinger-DeWitt equations, interpreted as a manifestly covariant quantum theory for the evolution of a system in spacetime, implies the existence of a five-dimensional pre-Maxwell field on the manifold of spacetime and proper time τ. The Maxwell theory is contained in this theory; integration of the field equations over τ restores the Maxwell equations with the usual interpretation of the sources. Following Schwinger's techniques, the authors study the Green's functions for the five dimensional hyperbolic field equations for both signatures ± [corresponding to O(4, 1) or O(3, 2) symmetry of the field equations] of the proper time derivative. The classification of the Green's functions follows that of the four-dimensional theory for massive fields, for which the mass squared may be positive or negative, respectively. The Green's function for the five-dimensional field are then given by the Fourier transform over the mass parameter. They derive the Green's functions corresponding to the principal part Δ P and the homogeneous function Δ t ; all of the Green's functions can be expressed in terms of these, as for the usual field equations with definite mass. In the O(3, 2) case, the principal part function has support for x 2 ≥ τ 2 , corresponding to spacelike propagation, as well as along the light cone X 2 = 0 (for τ = 0). There can be no transmission of information in spacelike directions, with this propagator, since the Maxwell field, obtained by integration over τ, does not contain this component of the support. Measurements are characterized by such an integration. The spacelike field therefore can dynamically establish spacelike correlations
Heavy-light mesons in lattice HQET and QCD
Guazzini, D.
2007-12-01
We present a study of a combination of HQET and relativistic QCD to extract the b-quark mass and the B s -meson decay constant from lattice quenched simulations. We start from a small volume, where one can directly simulate the b-quark, and compute the connection to a large volume, where finite size effects are negligible, through a finite size technique. The latter consists of steps extrapolated to the continuum limit, where the b-region is reached through interpolations guided by the effective theory. With the lattice spacing given in terms of the Sommer's scale r 0 and the experimental B s and K masses, we get the final results for the renormalization group invariant mass M b =6.88(10) GeV, translating into anti m b (anti m b )=4.42(6) GeV in the MS scheme, and f B s =191(6) MeV for the decay constant. A renormalization condition for the chromo-magnetic operator, responsible, at leading order in the heavy quark mass expansion of HQET, for the mass splitting between the pseudoscalar and the vector channel in mesonic heavy-light bound states, is provided in terms of lattice correlations functions which well suits a non-perturbative computation involving a large range of renormalization scales and no valence quarks. The two-loop expression of the corresponding anomalous dimension in the Schroedinger functional (SF) scheme is computed starting from results in the literature; it requires a one-loop calculation in the SF scheme with a non-vanishing background field. The cutoff effects affecting the scale evolution of the renormalization factors are studied at one-loop order, and confirmed by non-perturbative quenched computations to be negligible for the numerical precision achievable at present. (orig.)
Heavy-light mesons in lattice HQET and QCD
Guazzini, D.
2007-12-15
We present a study of a combination of HQET and relativistic QCD to extract the b-quark mass and the B{sub s}-meson decay constant from lattice quenched simulations. We start from a small volume, where one can directly simulate the b-quark, and compute the connection to a large volume, where finite size effects are negligible, through a finite size technique. The latter consists of steps extrapolated to the continuum limit, where the b-region is reached through interpolations guided by the effective theory. With the lattice spacing given in terms of the Sommer's scale r{sub 0} and the experimental B{sub s} and K masses, we get the final results for the renormalization group invariant mass M{sub b}=6.88(10) GeV, translating into anti m{sub b}(anti m{sub b})=4.42(6) GeV in the MS scheme, and f{sub B{sub s}}=191(6) MeV for the decay constant. A renormalization condition for the chromo-magnetic operator, responsible, at leading order in the heavy quark mass expansion of HQET, for the mass splitting between the pseudoscalar and the vector channel in mesonic heavy-light bound states, is provided in terms of lattice correlations functions which well suits a non-perturbative computation involving a large range of renormalization scales and no valence quarks. The two-loop expression of the corresponding anomalous dimension in the Schroedinger functional (SF) scheme is computed starting from results in the literature; it requires a one-loop calculation in the SF scheme with a non-vanishing background field. The cutoff effects affecting the scale evolution of the renormalization factors are studied at one-loop order, and confirmed by non-perturbative quenched computations to be negligible for the numerical precision achievable at present. (orig.)
Conformal correlation functions in the Brownian loop soup
Camia, Federico; Gandolfi, Alberto; Kleban, Matthew
2016-01-01
We define and study a set of operators that compute statistical properties of the Brownian loop soup, a conformally invariant gas of random Brownian loops (Brownian paths constrained to begin and end at the same point) in two dimensions. We prove that the correlation functions of these operators have many of the properties of conformal primaries in a conformal field theory, and compute their conformal dimension. The dimensions are real and positive, but have the novel feature that they vary continuously as a periodic function of a real parameter. We comment on the relation of the Brownian loop soup to the free field, and use this relation to establish that the central charge of the loop soup is twice its intensity.
Conformal correlation functions in the Brownian loop soup
Camia, Federico, E-mail: federico.camia@nyu.edu [New York University Abu Dhabi (United Arab Emirates); VU University, Amsterdam (Netherlands); Gandolfi, Alberto, E-mail: albertogandolfi@nyu.edu [New York University Abu Dhabi (United Arab Emirates); Università di Firenze (Italy); Kleban, Matthew, E-mail: kleban@nyu.edu [New York University Abu Dhabi (United Arab Emirates); Center for Cosmology and Particle Physics, Department of Physics, New York University (United States)
2016-01-15
We define and study a set of operators that compute statistical properties of the Brownian loop soup, a conformally invariant gas of random Brownian loops (Brownian paths constrained to begin and end at the same point) in two dimensions. We prove that the correlation functions of these operators have many of the properties of conformal primaries in a conformal field theory, and compute their conformal dimension. The dimensions are real and positive, but have the novel feature that they vary continuously as a periodic function of a real parameter. We comment on the relation of the Brownian loop soup to the free field, and use this relation to establish that the central charge of the loop soup is twice its intensity.
Conformal correlation functions in the Brownian loop soup
Federico Camia
2016-01-01
Full Text Available We define and study a set of operators that compute statistical properties of the Brownian loop soup, a conformally invariant gas of random Brownian loops (Brownian paths constrained to begin and end at the same point in two dimensions. We prove that the correlation functions of these operators have many of the properties of conformal primaries in a conformal field theory, and compute their conformal dimension. The dimensions are real and positive, but have the novel feature that they vary continuously as a periodic function of a real parameter. We comment on the relation of the Brownian loop soup to the free field, and use this relation to establish that the central charge of the loop soup is twice its intensity.
Hadronic slopes and cross-sections for vector mesons
Ferreira, Erasmo; Pereira, Flavio
1998-01-01
The data on photoproduction of vector mesons at high energies shows that the correlation between observables and their dependence on the energy and on the hadronic sizes which is characteristics of nonperturbative dynamics also appear in these processes. The analysis of the data exhibits effects of the interplay between perturbative and nonperturbative contributions. (author)
Evidence for the Production of Neutral Mesons by Photons
Steinberger, J; Panofsky, Wolfgang Kurt Hermann
1950-01-01
In the bombardment of nuclei by 330-Mev x-rays, multiple gamma-rays are emitted. From their angular correlation it is deduced that they are emitted in pairs in the disintegration of neutral particles moving with relativistic velocities and therefore of intermediate mass. The neutral mesons are produced with cross sections similar to those for the charged mesons and with an angular distribution peaked more in the forward direction. The production cross section in hydrogen and the production cross section per nucleon in C and Be are comparable.
Pulmonary alveolar proteinosis: Quantitative CT and pulmonary functional correlations
Guan, Yubao, E-mail: yubaoguan@163.com [Department of Radiology, the First Affiliated Hospital of Guangzhou Medical College, Guangzhou 510120 (China); State Key Laboratory of Respiratory Disease, Guangzhou 510120 (China); Zeng, Qingsi [Department of Radiology, the First Affiliated Hospital of Guangzhou Medical College, Guangzhou 510120 (China); Yang, Haihong; Zheng, Jinping; Li, Shiyue; Gao, Yi [State Key Laboratory of Respiratory Disease, Guangzhou 510120 (China); Deng, Yu [Department of Radiology, the First Affiliated Hospital of Guangzhou Medical College, Guangzhou 510120 (China); Mei, Jiang [State Key Laboratory of Respiratory Disease, Guangzhou 510120 (China); He, Jianxing, E-mail: jianxing63@163.com [State Key Laboratory of Respiratory Disease, Guangzhou 510120 (China); Zhong, Nanshan, E-mail: nanshan@vip.163.com [State Key Laboratory of Respiratory Disease, Guangzhou 510120 (China)
2012-09-15
Objective: We assessed the relationship between quantitative computer tomography (qCT) and the pulmonary function test (PFT) or blood gas analysis in pulmonary alveolar proteinosis (PAP) patients, as well as the utility of these analyses to monitor responses to whole lung lavage (WLL) therapy. Methods: Thirty-eight PAP patients simultaneously received a CT scan and PFT. Fifteen of these patients, undergoing sequential WLL for a total of 20 lavages, also underwent chest CT scans and blood gas analysis before and after WLL, and 14 of 15 patients underwent simultaneous PFT analysis. Differences between the qCT and PFT results were analyzed by canonical correlation. Results: PAP patients with low predicted values for FVC, FEV1, D{sub LCO} and D{sub LCO}/VA indicated small airspace volume and mean lung inflation, low airspace volume/total lung volume ratio and high mean lung density. Correlation and regression analysis revealed a strong correlation between D{sub LCO} and PaO{sub 2} values with CT results. The qCT results indicated that WLL significantly decreased lung weights and mean lung densities, and improved the total airspace volume/total lung volume ratios and mean lung inflations. Conclusion: Quantitative CT may be a sensitive tool for measuring the response of PAP patients to medical interventions such as WLL.
Correlation of anatomy and function in medulla oblongata infarction.
Eggers, C; Fink, G R; Möller-Hartmann, W; Nowak, D A
2009-02-01
A presentation of all aspects of the dorsolateral medulla oblongata syndrome is clinically very rare to find. In most cases patients present with fragmentary symptoms, e.g. ipsilateral axial lateropulsion, nystagmus, dysarthria, dysphagia or hemiataxia. However, the clinical presentation and lesion anatomy at the level of the medulla oblongata is still unsatisfactory. The aim of this study was to correlate the functional deficit with structural MRI-data. We included thirteen patients (eight male, five female, mean age 65.5) with medulla oblongata infarction with clinically predominant ipsilateral axial lateropulsion and correlated clinical with structural deficits. Magnetic resonance imaging lesion mapping demonstrated ipsilateral axial lateropulsion to result from lesions of the spinocerebellar tract, the inferior cerebellar peduncle or the inferior vestibular nucleus. Nystagmus was associated with lesions of the inferior vestibular nucleus, dissociated sensory loss with the spinothalamic tract and hemiataxia with the spinocerebellar tract. Correlating dysfunction and lesion anatomy is a promising approach to enhance our knowledge on medulla oblongata topography.
Summability of Connected Correlation Functions of Coupled Lattice Fields
Lukkarinen, Jani; Marcozzi, Matteo; Nota, Alessia
2018-04-01
We consider two nonindependent random fields ψ and φ defined on a countable set Z. For instance, Z=Z^d or Z=Z^d× I, where I denotes a finite set of possible "internal degrees of freedom" such as spin. We prove that, if the cumulants of ψ and φ enjoy a certain decay property, then all joint cumulants between ψ and φ are ℓ _2-summable in the precise sense described in the text. The decay assumption for the cumulants of ψ and φ is a restricted ℓ _1 summability condition called ℓ _1-clustering property. One immediate application of the results is given by a stochastic process ψ _t(x) whose state is ℓ _1-clustering at any time t: then the above estimates can be applied with ψ =ψ _t and φ =ψ _0 and we obtain uniform in t estimates for the summability of time-correlations of the field. The above clustering assumption is obviously satisfied by any ℓ _1-clustering stationary state of the process, and our original motivation for the control of the summability of time-correlations comes from a quest for a rigorous control of the Green-Kubo correlation function in such a system. A key role in the proof is played by the properties of non-Gaussian Wick polynomials and their connection to cumulants
On form factors and correlation functions in twistor space
Koster, Laura; Mitev, Vladimir; Staudacher, Matthias; Wilhelm, Matthias
2017-01-01
In this paper, we continue our study of form factors and correlation functions of gauge-invariant local composite operators in the twistor-space formulation of N=4 super Yang-Mills theory. Using the vertices for these operators obtained in our recent papers (DOI: 10.1103/PhysRevLett.117.011601; 10.1007/JHEP06(2016)162 ), we show how to calculate the twistor-space diagrams for general N k MHV form factors via the inverse soft limit, in analogy to the amplitude case. For general operators without α-dot indices, we then reexpress the NMHV form factors from the position-twistor calculation in terms of momentum twistors, deriving and expanding on a relation between the two twistor formalisms previously observed in the case of amplitudes. Furthermore, we discuss the calculation of generalized form factors and correlation functions as well as the extension to loop level, in particular providing an argument promised in https://www.doi.org/10.1002/prop.201400085.
Twist operator correlation functions in O(n) loop models
Simmons, Jacob J H; Cardy, John
2009-01-01
Using conformal field theoretic methods we calculate correlation functions of geometric observables in the loop representation of the O(n) model at the critical point. We focus on correlation functions containing twist operators, combining these with anchored loops, boundaries with SLE processes and with double SLE processes. We focus further upon n = 0, representing self-avoiding loops, which corresponds to a logarithmic conformal field theory (LCFT) with c = 0. In this limit the twist operator plays the role of a 0-weight indicator operator, which we verify by comparison with known examples. Using the additional conditions imposed by the twist operator null states, we derive a new explicit result for the probabilities that an SLE 8/3 winds in various ways about two points in the upper half-plane, e.g. that the SLE passes to the left of both points. The collection of c = 0 logarithmic CFT operators that we use deriving the winding probabilities is novel, highlighting a potential incompatibility caused by the presence of two distinct logarithmic partners to the stress tensor within the theory. We argue that both partners do appear in the theory, one in the bulk and one on the boundary and that the incompatibility is resolved by restrictive bulk-boundary fusion rules
Adrenal phaeochromocytoma: correlation of MRI appearances with histology and function
Jacques, Audrey E.T.; Sahdev, Anju; Sandrasagara, Madrika; Rockall, Andrea G.; Reznek, Rodney H.; Goldstein, Rick; Chew, Shern; Berney, Daniel
2008-01-01
The purpose of this study was to describe the range of appearances of adrenal phaeochromocytomas on T2-weighted MRI, correlate appearances with histopathology, and quantify the incidence of the previously described hyperintense appearance. The appearance and MR characteristics of 44 phaeochromocytomas were reviewed retrospectively. T2-weighted appearances were grouped: (1) 'classical', homogeneous, high signal intensity, isointense to CSF; (2) homogeneous, isointense or minimally hyperintense to spleen, hypointense to CSF; (3) heterogeneous, marbled appearance; (4) heterogeneous, multiple high signal intensity pockets. All 44 adrenal phaeochromocytomas were well circumscribed, 1.2-15 cm in maximum diameter, with no visual or quantitative signal loss on chemical shift imaging. On T2-weighted MRI 5/44 (11%) had group 1 appearance; 15/44 (34%) group 2, 7/44 (16%) group 3; and 17/44 (39%) group 4. Homogeneous group 1 and 2 lesions were smaller (mean 4.5 cm) than heterogeneous group 3 and 4 lesions (mean 6.3 cm). Increasing MRI heterogeneity correlated pathologically with increasing amounts of haemorrhage, necrosis and fibrosis. No MRI features were predictive of malignancy. Non-functioning phaeochromocytomas were larger than functioning lesions. No size difference was seen between syndrome and sporadic lesions. In this large series we report a wide range of appearances of adrenal phaeochromocytomas on T2-weighted MRI. The previously described classical hyperintense phaeochromocytoma is relatively uncommon. (orig.)
Correlating Function and Imaging Measures of the Medial Longitudinal Fasciculus.
Ken Sakaie
Full Text Available To test the validity of diffusion tensor imaging (DTI measures of tissue injury by examining such measures in a white matter structure with well-defined function, the medial longitudinal fasciculus (MLF. Injury to the MLF underlies internuclear ophthalmoparesis (INO.40 MS patients with chronic INO and 15 healthy controls were examined under an IRB-approved protocol. Tissue integrity of the MLF was characterized by DTI parameters: longitudinal diffusivity (LD, transverse diffusivity (TD, mean diffusivity (MD and fractional anisotropy (FA. Severity of INO was quantified by infrared oculography to measure versional disconjugacy index (VDI.LD was significantly lower in patients than in controls in the medulla-pons region of the MLF (p < 0.03. FA was also lower in patients in the same region (p < 0.0004. LD of the medulla-pons region correlated with VDI (R = -0.28, p < 0.05 as did FA in the midbrain section (R = 0.31, p < 0.02.This study demonstrates that DTI measures of brain tissue injury can detect injury to a functionally relevant white matter pathway, and that such measures correlate with clinically accepted evaluation indices for INO. The results validate DTI as a useful imaging measure of tissue integrity.
On form factors and correlation functions in twistor space
Koster, Laura [Institut für Mathematik, Institut für Physik und IRIS Adlershof,Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, 12489 Berlin (Germany); Mitev, Vladimir [PRISMA Cluster of Excellence, Institut für Physik, WA THEP,Johannes Gutenberg-Universität Mainz,Staudingerweg 7, 55128 Mainz (Germany); Staudacher, Matthias [Institut für Mathematik, Institut für Physik und IRIS Adlershof,Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, 12489 Berlin (Germany); Wilhelm, Matthias [Niels Bohr Institute, Copenhagen University,Blegdamsvej 17, 2100 Copenhagen Ø (Denmark)
2017-03-24
In this paper, we continue our study of form factors and correlation functions of gauge-invariant local composite operators in the twistor-space formulation of N=4 super Yang-Mills theory. Using the vertices for these operators obtained in our recent papers (DOI: 10.1103/PhysRevLett.117.011601; 10.1007/JHEP06(2016)162 ), we show how to calculate the twistor-space diagrams for general N{sup k}MHV form factors via the inverse soft limit, in analogy to the amplitude case. For general operators without α-dot indices, we then reexpress the NMHV form factors from the position-twistor calculation in terms of momentum twistors, deriving and expanding on a relation between the two twistor formalisms previously observed in the case of amplitudes. Furthermore, we discuss the calculation of generalized form factors and correlation functions as well as the extension to loop level, in particular providing an argument promised in https://www.doi.org/10.1002/prop.201400085.
Correlation functions in unitary minimal Liouville gravity and Frobenius manifolds
Belavin, V. [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky prospect 53, 119991 Moscow (Russian Federation); Department of Quantum Physics, Institute for Information Transmission Problems,Bolshoy Karetny per. 19, 127994 Moscow (Russian Federation); Department of Theoretical Physics, National Research Nuclear University MEPhI,Kashirskoe shosse 31, 115409 Moscow (Russian Federation)
2015-02-10
We continue to study minimal Liouville gravity (MLG) using a dual approach based on the idea that the MLG partition function is related to the tau function of the A{sub q} integrable hierarchy via the resonance transformations, which are in turn fixed by conformal selection rules. One of the main problems in this approach is to choose the solution of the Douglas string equation that is relevant for MLG. The appropriate solution was recently found using connection with the Frobenius manifolds. We use this solution to investigate three- and four-point correlators in the unitary MLG models. We find an agreement with the results of the original approach in the region of the parameters where both methods are applicable. In addition, we find that only part of the selection rules can be satisfied using the resonance transformations. The physical meaning of the nonzero correlators, which before coupling to Liouville gravity are forbidden by the selection rules, and also the modification of the dual formulation that takes this effect into account remains to be found.
The Self-Correlation Function of Real Gases
Sigmar, D.J.
1965-01-01
In the formal theory of inelastic scattering of neutrons, the self-correlation function has been worked out in terms of statistical averages of the derivatives of die N-body interaction-potential of the scatterer. In the present paper, these averages are evaluated for real gases by means of a cluster-expansion related to that of Mayer-Ursell. This leads to certain non-linear types of clusters, which are investigated with respect to the topology of the graphs, their multiplicity (by combinatorial analysis) and their quadrature. As one expects, in view of the many-body problem, some of the clusters are not separable and have to be machine-integrated. In this way, the self-correlation function γ s (K, t) is cálculated for short times, including also the first non-Gaussian term. The cluster-expansion breaks off after the first interaction term, so that the results are valid for low density only. This still gives rise to very many different types of clusters, containing up to seven points, for each coefficient. The assumed potential is a general two-particle, hard-core type. As Singwi et al. have shown, the long time behaviour of γs is determined by the time integral of the velocity auto-correlation: ∫ ∞ 0 K (0) V K (t) > T dt. To construct the integrand for all times, we can make use of our cluster-expansion for small t and adopt Langevin’s diffusion theory for large t. Numerical computations are under way. (author) [fr
Feng Weiguo; Wang Hongwei; Wu Xiang
1989-12-01
Based on the real space Correlated-Basis-Functions theory and the collective oscillation behaviour of the electron gas with effective Coulomb interaction, the many body wave function is obtained for the quasi-two-dimensional electron system in the semiconductor inversion layer. The pair-correlation function and the correlation energy of the system have been calculated by the integro-differential method in this paper. The comparison with the other previous theoretical results is also made. The new theoretical approach and its numerical results show that the pair-correlation functions are definitely positive and satisfy the normalization condition. (author). 10 refs, 2 figs
A study of correlation functions for the delta-function fermi gas
Berkovich, A.
1987-01-01
In this dissertation, the author considers the quantum nonlinear Schrodinger model, describing a non-relativistic, finite-density gas of one-dimensional fermions with repulsive delta-function interaction. The author employs the quantum inverse scattering method and temperature Green function technique to derive some new results for the two-point, equal-time correlation function. For the case of zero temperature, it is shown that the correlation function in the infinite coupling limit (c → ∞) can be expressed concisely in terms of the solution of the Painleve equation of the fifth kind. The author, then, extends this result and obtains an exact expression for the order (1/c) correction to the two-point function in terms of the Painleve transcendents. This work is essentially self-contained; both old and new results are presented and discussed at some length
Śmiga, Szymon; Fabiano, Eduardo; Laricchia, Savio; Constantin, Lucian A; Della Sala, Fabio
2015-04-21
We analyze the methodology and the performance of subsystem density functional theory (DFT) with meta-generalized gradient approximation (meta-GGA) exchange-correlation functionals for non-bonded molecular systems. Meta-GGA functionals depend on the Kohn-Sham kinetic energy density (KED), which is not known as an explicit functional of the density. Therefore, they cannot be directly applied in subsystem DFT calculations. We propose a Laplacian-level approximation to the KED which overcomes this limitation and provides a simple and accurate way to apply meta-GGA exchange-correlation functionals in subsystem DFT calculations. The so obtained density and energy errors, with respect to the corresponding supermolecular calculations, are comparable with conventional approaches, depending almost exclusively on the approximations in the non-additive kinetic embedding term. An embedding energy error decomposition explains the accuracy of our method.
Correlations between respiratory and functional variables in heart failure
FÃ¡bio Cangeri Di Naso
2009-09-01
Full Text Available Background: Respiratory alterations can impact on the functional performance of patients with heart failure. Aim: To correlate maximum inspiratory muscular force and lung function variables with functional capacity in heart failure patients. Methods: A transversal study January-July 2007 with 42 chronic heart disease patients (28 males with no prior pulmonary illness. The patients were in New York Heart Association Functional Class I, II and III. The variables used were maximum inspiratory pressure, forced vital capacity and forced expiratory volume in the first second. Respiratory variables measured were distance covered in the six-minute walk test, NYHA functional class and the physical functioning domain of the Short Form-36 Quality of Life Questionnaire. Results: Maximum inspiratory pressure correlated with the six-minute walk test (rÂ =Â 0.543 and pÂ <Â 0.001, functional capacity (rÂ =Â â0.566 and pÂ <Â 0.001 and the physical functioning domain score of the Short Form-36 (rÂ =Â 0.459 and pÂ =Â 0.002. The same was true of forced vital capacity and the six-minute walk test (rÂ =Â 0.501 and pÂ =Â 0.001, functional capacity (rÂ =Â â0.477 and pÂ =Â 0.001 and Short Form-36 (rÂ =Â 0.314 and pÂ =Â 0.043 variables. Forced expiratory volume correlated with the distance covered in the six-minute walk test (rÂ =Â 0.514 and pÂ <Â 0.001 and functional capacity (rÂ =Â â0.383 and pÂ =Â 0.012. Conclusion: Lung function and inspiratory muscular force respiratory variables correlated with functional variables in patients with heart failure. Resumo: Fundamento: AlteraÃ§Ãµes respiratÃ³rias podem influenciar o desempenho funcional em doentes com insuficiÃªncia cardÃaca (IC. Objectivo: Correlacionar a forÃ§a muscular inspiratÃ³ria mÃ¡xima (PImax e as variÃ¡veis da funÃ§Ã£o pulmonar com a capacidade funcional em doentes com IC. MÃ©todos: Estudo transversal
O.V.Patsahan
2006-01-01
Full Text Available Based on the method of collective variables (CV with a reference system, the exact expression for the functional of the grand partition function of a m-component ionic model with charge and size asymmetry is found. Particular attention is paid to the n-th particle correlation functions of the reference system which is presented as a m-component system of "colour" hard spheres of the same diameter. A two-component model is considered in more detail. In this case the recurrence formulas for the correlation functions are found. A general case of a m-component inhomogeneous system of the "colour" hard spheres is also analysed.
Singular value correlation functions for products of Wishart random matrices
Akemann, Gernot; Kieburg, Mario; Wei, Lu
2013-01-01
We consider the product of M quadratic random matrices with complex elements and no further symmetry, where all matrix elements of each factor have a Gaussian distribution. This generalizes the classical Wishart–Laguerre Gaussian unitary ensemble with M = 1. In this paper, we first compute the joint probability distribution for the singular values of the product matrix when the matrix size N and the number M are fixed but arbitrary. This leads to a determinantal point process which can be realized in two different ways. First, it can be written as a one-matrix singular value model with a non-standard Jacobian, or second, for M ⩾ 2, as a two-matrix singular value model with a set of auxiliary singular values and a weight proportional to the Meijer G-function. For both formulations, we determine all singular value correlation functions in terms of the kernels of biorthogonal polynomials which we explicitly construct. They are given in terms of the hypergeometric and Meijer G-functions, generalizing the Laguerre polynomials for M = 1. Our investigation was motivated from applications in telecommunication of multi-layered scattering multiple-input and multiple-output channels. We present the ergodic mutual information for finite-N for such a channel model with M − 1 layers of scatterers as an example. (paper)
Unified Chiral models of mesons and baryons
Mendez-Galain, R.; Ripka, G.
1990-01-01
Unified Chiral models of mesons and baryons are presented. Emphasis is placed on the underlying quark structure of hadrons including the Skyrmion. The Nambu Jona-Lasinio model with vector mesons is discussed
Holographic corrections to meson scattering amplitudes
Armoni, Adi; Ireson, Edwin, E-mail: 746616@swansea.ac.uk
2017-06-15
We compute meson scattering amplitudes using the holographic duality between confining gauge theories and string theory, in order to consider holographic corrections to the Veneziano amplitude and associated higher-point functions. The generic nature of such computations is explained, thanks to the well-understood nature of confining string backgrounds, and two different examples of the calculation in given backgrounds are used to illustrate the details. The effect we discover, whilst only qualitative, is re-obtainable in many such examples, in four-point but also higher point amplitudes.
Spectroscopic properties of the B meson
Devlani Nayneshkumar
2015-01-01
Full Text Available Investigation of the B(bq̄; q = u, d meson properties is carried out using variational method within phenomenological quark antiquark potential(coulomb plus power model using the Gaussian wave function. O(1/m correction to the potential energy term and relativistic corrections to the kinetic energy term of the hamiltonian are incorporated. Spin-orbit, spin-spin and tensor interactions are employed to obtain the mass spectra. Various other properties such as the decay constants, e1 and m1 transitions are also obtained
Strange mesons in dense nuclear matter
Senger, P.
2000-10-01
Experimental data on the production of kaons and antikaons in heavy ion collisions at relativistic energies are reviewed with respect to in-medium effects. The K - /K + ratios measured in nucleus-nucleus collisions are 1-2 orders of magnitude larger than in proton-proton collisions. The azimuthal angle distributions of K + mesons indicate a repulsive kaon-nucleon potential. Microscopic transport calculations consistently explain both the yields and the emission patterns of kaons and antikaons when assuming that their properties are modified in dense nuclear matter. The K + production excitation functions measured in light and heavy collision systems provide evidence for a soft nuclear equation-of-state. (orig.)
Deep electroproduction of exotic hybrid mesons
Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.
2004-01-01
We evaluate the leading order amplitude for the deep exclusive electroproduction of an exotic hybrid meson in the Bjorken regime. We show that, contrarily to naive expectation, this amplitude factorizes at the twist 2 level and thus scales like usual meson electroproduction when the virtual photon and the hybrid meson are longitudinally polarized. Exotic hybrid mesons may thus be studied in electroproduction experiments at JLAB, HERA (HERMES) or CERN (Compass)
Nature of the light scalar mesons
Vijande, J.; Valcarce, A.; Fernandez, F.; Silvestre-Brac, B.
2005-01-01
Despite the apparent simplicity of meson spectroscopy, light scalar mesons cannot be accommodated in the usual qq structure. We study the description of the scalar mesons below 2 GeV in terms of the mixing of a chiral nonet of tetraquarks with conventional qq states. A strong diquark-antidiquark component is found for several states. The consideration of a glueball as dictated by quenched lattice QCD drives a coherent picture of the isoscalar mesons
Boos, H.E.; Shiroishi, M.; Takahashi, M.
2005-01-01
We show how correlation functions of the spin-1/2 Heisenberg chain without magnetic field in the anti-ferromagnetic ground state can be explicitly calculated using information contained in the quantum Knizhnik-Zamolodchikov equation [qKZ]. We find several fundamental relations which the inhomogeneous correlations should fulfill. On the other hand, it turns out that these relations can fix the form of the correlations uniquely. Actually, applying this idea, we have obtained all the correlation functions on five sites. Particularly by taking the homogeneous limit, we have got the analytic form of the fourth-neighbor pair correlator j z S j+4 z >
The velocity correlation function in cosmic-ray diffusion theory
Forman, M.A.
1977-01-01
The concept of velocity correlation functions is introduced and applied to the calculation of cosmic ray spatial diffusion coefficients. It is assumed that the pitch angle scattering coefficient is already known from some other theory, and is reasonably well-behaved. Previous results for the coefficient for diffusion parallel to the mean field are recovered when the velocity-changing mechanism is artificially restricted to pitch angle scattering. The velocity correlation method is then applied to the more general case where there are fluctuations in the local mean field. It is found that the parallel diffusion coefficient is reduced in proportion to the amplitude of the field fluctuations, and that the ratio of the perpendicular to parallel diffusion coefficients cannot be greater than 2 >/B 0 2 . It is shown in the appendix that the Liouville form of the scattering equation implies that the Fokker-Planck coefficients (Δμ 2 )/Δt=2Dsub(μμ) and (Δμ)/Δt=deltaDsub(μμ)/deltaμ, and that all higher-order coefficients are identically zero. (Auth.)
Functional Cortical Network in Alpha Band Correlates with Social Bargaining
Billeke, Pablo; Zamorano, Francisco; Chavez, Mario; Cosmelli, Diego; Aboitiz, Francisco
2014-01-01
Solving demanding tasks requires fast and flexible coordination among different brain areas. Everyday examples of this are the social dilemmas in which goals tend to clash, requiring one to weigh alternative courses of action in limited time. In spite of this fact, there are few studies that directly address the dynamics of flexible brain network integration during social interaction. To study the preceding, we carried out EEG recordings while subjects played a repeated version of the Ultimatum Game in both human (social) and computer (non-social) conditions. We found phase synchrony (inter-site-phase-clustering) modulation in alpha band that was specific to the human condition and independent of power modulation. The strength and patterns of the inter-site-phase-clustering of the cortical networks were also modulated, and these modulations were mainly in frontal and parietal regions. Moreover, changes in the individuals’ alpha network structure correlated with the risk of the offers made only in social conditions. This correlation was independent of changes in power and inter-site-phase-clustering strength. Our results indicate that, when subjects believe they are participating in a social interaction, a specific modulation of functional cortical networks in alpha band takes place, suggesting that phase synchrony of alpha oscillations could serve as a mechanism by which different brain areas flexibly interact in order to adapt ongoing behavior in socially demanding contexts. PMID:25286240
Correlation functions and susceptibilities of photonics band gap reservoirs
Konopka, M.
1998-01-01
We investigate quantum statistical properties of photonic band gap reservoirs in terms of correlation functions and susceptibilities in time and spectral domains. Typical features are oscillations of the time-dependent correlation functions and susceptibilities. This is because photonic bad gap reservoirs are intrinsically non-Markovian reservoirs. The results help us to understand better how intrinsic quantum-statistical properties of a reservoir influence dynamics of an atom interacting with this reservoir. Boundary conditions influence time and spectral properties of the electromagnetic field. This well-known fact has a great importance in optics and generally in electromagnetism. Specific examples are resonators used in laser technique and cavity electrodynamics. In quantum optics high-Q micro cavities are used for single-atom experiments when an atom can interact in a coherent way with an electromagnetic field which has its mode structure totally different from those in free space. In particular, interaction of an (effectively) two-level atom with a single-mode cavity field was observed in the region of microwaves (with the wavelength about 1 cm). In 1987 Yablonovitch and John independently proposed that certain periodic dielectric structures can present forbidden frequency gaps (or pseudo gaps in partially disordered structures) for transverse modes. Such periodic structures were named 'photonic band structures' or 'photonic crystals', in analogy with electronic crystals which also have a (forbidden) gap for electronic energy. For true photonic crystals the basic property of blocking electromagnetic wave propagation must be fulfilled for all waves within some frequency range, i.e. for all wavevector and polarization directions
Chiral symmetry breaking and the spin content of the {rho} and {rho}{sup '} mesons
Glozman, L.Ya., E-mail: leonid.glozman@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria); Lang, C.B., E-mail: christian.lang@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria); Limmer, M., E-mail: markus.limmer@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria)
2011-11-03
Using interpolators with different SU(2){sub L}xSU(2){sub R} transformation properties we study the chiral symmetry and spin contents of the {rho} and {rho}{sup '} mesons in lattice simulations with dynamical quarks. A ratio of couplings of the q-bar {gamma}{sup i}{tau}q and q-bar {sigma}{sup 0}i{tau}q interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of {approx}1 fm. In the ground state {rho} meson the chiral symmetry is strongly broken with comparable contributions of both the (0,1)+(1,0) and (1/2,1/2){sub b} chiral representations with the former being the leading contribution. In contrast, in the {rho}{sup '} meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1/2,1/2){sub b}. Using a unitary transformation from the chiral basis to the {sup 2S+1}L{sub J} basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The {rho} meson is practically a {sup 3}S{sub 1} state with no obvious trace of a 'spin crisis'. The {rho}{sup '} meson has a sizeable contribution of the {sup 3}D{sub 1} wave, which implies that the {rho}{sup '} meson cannot be considered as a pure radial excitation of the {rho} meson.
Chiral symmetry breaking and the spin content of the ρ and ρ‧ mesons
Glozman, L. Ya.; Lang, C. B.; Limmer, M.
2011-11-01
Using interpolators with different SU(2)L × SU(2)R transformation properties we study the chiral symmetry and spin contents of the ρ and ρ‧ mesons in lattice simulations with dynamical quarks. A ratio of couplings of the qbarγi τq and qbarσ0i τq interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of ∼ 1 fm. In the ground state ρ meson the chiral symmetry is strongly broken with comparable contributions of both the (0 , 1) + (1 , 0) and (1 / 2 , 1 / 2) b chiral representations with the former being the leading contribution. In contrast, in the ρ‧ meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1 / 2 , 1 / 2) b. Using a unitary transformation from the chiral basis to the LJ2S+1 basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The ρ meson is practically a 3S1 state with no obvious trace of a "spin crisis". The ρ‧ meson has a sizeable contribution of the 3D1 wave, which implies that the ρ‧ meson cannot be considered as a pure radial excitation of the ρ meson.
Chiral symmetry breaking and the spin content of the ρ and ρ' mesons
Glozman, L.Ya.; Lang, C.B.; Limmer, M.
2011-01-01
Using interpolators with different SU(2) L xSU(2) R transformation properties we study the chiral symmetry and spin contents of the ρ and ρ ' mesons in lattice simulations with dynamical quarks. A ratio of couplings of the q-bar γ i τq and q-bar σ 0i τq interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of ∼1 fm. In the ground state ρ meson the chiral symmetry is strongly broken with comparable contributions of both the (0,1)+(1,0) and (1/2,1/2) b chiral representations with the former being the leading contribution. In contrast, in the ρ ' meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1/2,1/2) b . Using a unitary transformation from the chiral basis to the 2S+1 L J basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The ρ meson is practically a 3 S 1 state with no obvious trace of a 'spin crisis'. The ρ ' meson has a sizeable contribution of the 3 D 1 wave, which implies that the ρ ' meson cannot be considered as a pure radial excitation of the ρ meson.
Production of excited charmed mesons at LEP
Abbaneo, D
2000-01-01
Studies od the production of orbitally excited charmed and charmed strange mesons in e+e- collisions, performed by the LEP collaborations are reviewed. Measurements of the production rates of orbitally excited charmed mesons in semileptonic b decays are presented. Searches for charmed meson radial excitations are also briefly discussed.
Two-point boundary correlation functions of dense loop models
Alexi Morin-Duchesne, Jesper Lykke Jacobsen
2018-06-01
Full Text Available We investigate six types of two-point boundary correlation functions in the dense loop model. These are defined as ratios $Z/Z^0$ of partition functions on the $m\\times n$ square lattice, with the boundary condition for $Z$ depending on two points $x$ and $y$. We consider: the insertion of an isolated defect (a and a pair of defects (b in a Dirichlet boundary condition, the transition (c between Dirichlet and Neumann boundary conditions, and the connectivity of clusters (d, loops (e and boundary segments (f in a Neumann boundary condition. For the model of critical dense polymers, corresponding to a vanishing loop weight ($\\beta = 0$, we find determinant and pfaffian expressions for these correlators. We extract the conformal weights of the underlying conformal fields and find $\\Delta = -\\frac18$, $0$, $-\\frac3{32}$, $\\frac38$, $1$, $\\tfrac \\theta \\pi (1+\\tfrac{2\\theta}\\pi$, where $\\theta$ encodes the weight of one class of loops for the correlator of type f. These results are obtained by analysing the asymptotics of the exact expressions, and by using the Cardy-Peschel formula in the case where $x$ and $y$ are set to the corners. For type b, we find a $\\log|x-y|$ dependence from the asymptotics, and a $\\ln (\\ln n$ term in the corner free energy. This is consistent with the interpretation of the boundary condition of type b as the insertion of a logarithmic field belonging to a rank two Jordan cell. For the other values of $\\beta = 2 \\cos \\lambda$, we use the hypothesis of conformal invariance to predict the conformal weights and find $\\Delta = \\Delta_{1,2}$, $\\Delta_{1,3}$, $\\Delta_{0,\\frac12}$, $\\Delta_{1,0}$, $\\Delta_{1,-1}$ and $\\Delta_{\\frac{2\\theta}\\lambda+1,\\frac{2\\theta}\\lambda+1}$, extending the results of critical dense polymers. With the results for type f, we reproduce a Coulomb gas prediction for the valence bond entanglement entropy of Jacobsen and Saleur.
A phenomenological analysis of non-resonant charm meson decays
Bediaga, I.; Goebel, C.; Mendez-Galain, R.
1997-07-01
We analyse the consequences of the usual assumption of a constant function to fit non-resonant decays from experimental Dalitz plot describing charmed meson decays. We first show, using the D + -> K 0 π + π 0 decay channel as an example, how an inadequate extraction of the non-resonant contribution could yield incorrect measurements for the resonant channels. We analyse how the correct study of this decay will provide a test for the validity of factorization in D meson decays. Finally, we show how form factors that can be measured from the D + s -> π - π + π + decay. We emphasize its relevance for the study of the decay τ -> v t 3π and the extraction of the α 1 meson width. (author)
A phenomenological analysis of non-resonant charm meson decays
Bediaga, I.; Goebel, C. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Mendez-Galain, R. [Montevideo Univ. (Uruguay). Facultad de Ingenieria
1997-07-01
We analyse the consequences of the usual assumption of a constant function to fit non-resonant decays from experimental Dalitz plot describing charmed meson decays. We first show, using the D{sup +} -> K{sup 0} {pi}{sup +} {pi}{sup 0} decay channel as an example, how an inadequate extraction of the non-resonant contribution could yield incorrect measurements for the resonant channels. We analyse how the correct study of this decay will provide a test for the validity of factorization in D meson decays. Finally, we show how form factors that can be measured from the D{sup +}{sub s} -> {pi}{sup -} {pi}{sup +} {pi}{sup +} decay. We emphasize its relevance for the study of the decay {tau} -> v{sub t} 3{pi} and the extraction of the {alpha}{sub 1} meson width. (author) 26 refs., 6 figs.
Analytic structure of ρ meson propagator at finite temperature
Ghosh, Sabyasachi; Sarkar, Sourav; Mallik, S.
2010-01-01
We analyse the structure of one-loop self-energy graphs for the ρ meson in real time formulation of finite temperature field theory. We find the discontinuities of these graphs across the unitary and the Landau cuts. These contributions are identified with different sources of medium modification discussed in the literature. We also calculate numerically the imaginary and the real parts of the self-energies and construct the spectral function of the ρ meson, which are compared with an earlier determination. A significant contribution arises from the unitary cut of the πω loop, that was ignored so far in the literature. (orig.)
Nucleon quark structure and strong meson-nucleon form factors
Efimov, G.V.; Ivanov, M.A.
1987-01-01
The nucleon is considered as a three-quark system in virton-quark model. The main statistic properties of proton and neutron are calculated: magnetic moments, electromagnetic radii, G A /G V ratio in weak neutron decay. Strong meson-nucleon form factors which determine nucleon-nucleon potential are obtained as a function of squared transfer momentum of mesons. The results are compared with phenomenological form factors used for description of phases of NN-scattering in the one-boson-, exchange model
Dilepton and vector meson production in heavy-ion reactions
Wolf, Gy.
1997-01-01
A nonperturbative dynamical study of dilepton an vector meson production in heavy-ion collisions from 1 to 2 GeV/A bombarding energies is presented incorporating all known sources relevant in this energy range. The dynamical evolution of the nucleus-nucleus collision is described by a transport equation of the Boltzmann-Uehling-Uhlenbeck type evolving phase-space distribution functions for nucleons, baryon resonances, pions, η's, ρ's and σ's with their isospin degrees of freedom. In particular, the sensitivity of the calculated yields to predicted changes of the ρ and ω mesons in dense matter is investigated. (author)
Pennington, M.R.
1988-09-01
The search of I = 0 0 ++ mesons is described. We highlight the crucial role played by the states in the 1 GeV region. An analysis program that with unimpeachable data would produce definitive results on these is outlined and shown with present data to provide prima facie evidence for dynamics beyond that of the quark model. We briefly speculate on the current status of the lowest mass scalar mesons and discuss how experiment can resolve the unanswered issues. 30 refs., 6 figs., 1 tab
A search for unconventional mesons
Turnau, J.
1984-01-01
Selected problems of the fixed target meson spectroscopy connected with the issue of unconventional states glueballs, hybrides and four-quarks are discussed. The experimental basis of the dissertation consists of some results of the WA3 experiment performed by ACCMOR collaboration (Π - p→(3Π) - p, K - p→K - Π + Π - p, Π - p→K s o K s o n) and of the S136 experiment performed by CCM collaborations (Π - p↑→Π + Π - n, Π - p↑→K + K - n). Mesons with spin parities J PC = 0 -+ , 0 ++ , 1 ++ and 2 ++ are discussed from the point of view of the phenomenology of unconventional states. (author)
Behavioral correlates of anxiety in well-functioning older adults.
Losada, Andrés; Márquez-González, María; Pachana, Nancy A; Wetherell, Julie L; Fernández-Fernández, Virginia; Nogales-González, Celia; Ruiz-Díaz, Miguel
2015-07-01
Research on the behavioral correlates of anxiety in older adults is sparse. The aim of this study was to explore the association of anxiety with behavioral patterns defined by health, activity, emotional and social variables. A convenience sample of 395 older adults completed measures of health, activity, emotions, social variables and experiential avoidance. Cross-sectional data were analysed using cluster analysis. Five clusters were identified: active healthy, healthy, active vulnerable, lonely inactive and frail lonely. Participants in the active healthy and healthy clusters showed the highest scores on health variables (vitality and physical function), and adaptive scores on the rest of variables. They also reported the lowest scores on anxiety and included the lowest number of cases with clinically significant anxiety levels. Active vulnerable showed high scores on social support, leisure activities and capitalization on them but low scores in vitality and physical functioning. Participants in the lonely inactive cluster reported the highest mean score in experiential avoidance and high scores on boredom and loneliness, and low scores on social support, leisure activities capitalizing on pleasant activities and health variables. Frail lonely represent a particularly vulnerable profile of participants, similar to that of lonely inactive, but with significantly lower scores on health variables and higher scores on boredom and hours watching TV. Anxiety in older adults is not only linked to poor health, but also to dysfunctional social behavior, loneliness, boredom and experiential avoidance. Maladaptive profiles of older adults with regard to these variables have been identified.
Elucidation of spin echo small angle neutron scattering correlation functions through model studies.
Shew, Chwen-Yang; Chen, Wei-Ren
2012-02-14
Several single-modal Debye correlation functions to approximate part of the overall Debey correlation function of liquids are closely examined for elucidating their behavior in the corresponding spin echo small angle neutron scattering (SESANS) correlation functions. We find that the maximum length scale of a Debye correlation function is identical to that of its SESANS correlation function. For discrete Debye correlation functions, the peak of SESANS correlation function emerges at their first discrete point, whereas for continuous Debye correlation functions with greater width, the peak position shifts to a greater value. In both cases, the intensity and shape of the peak of the SESANS correlation function are determined by the width of the Debye correlation functions. Furthermore, we mimic the intramolecular and intermolecular Debye correlation functions of liquids composed of interacting particles based on a simple model to elucidate their competition in the SESANS correlation function. Our calculations show that the first local minimum of a SESANS correlation function can be negative and positive. By adjusting the spatial distribution of the intermolecular Debye function in the model, the calculated SESANS spectra exhibit the profile consistent with that of hard-sphere and sticky-hard-sphere liquids predicted by more sophisticated liquid state theory and computer simulation. © 2012 American Institute of Physics
Zhou, Yongxi; Ernzerhof, Matthias; Bahmann, Hilke
2015-01-01
Drawing on the adiabatic connection of density functional theory, exchange-correlation functionals of Kohn-Sham density functional theory are constructed which interpolate between the extreme limits of the electron-electron interaction strength. The first limit is the non-interacting one, where there is only exchange. The second limit is the strong correlated one, characterized as the minimum of the electron-electron repulsion energy. The exchange-correlation energy in the strong-correlation limit is approximated through a model for the exchange-correlation hole that is referred to as nonlocal-radius model [L. O. Wagner and P. Gori-Giorgi, Phys. Rev. A 90, 052512 (2014)]. Using the non-interacting and strong-correlated extremes, various interpolation schemes are presented that yield new approximations to the adiabatic connection and thus to the exchange-correlation energy. Some of them rely on empiricism while others do not. Several of the proposed approximations yield the exact exchange-correlation energy for one-electron systems where local and semi-local approximations often fail badly. Other proposed approximations generalize existing global hybrids by using a fraction of the exchange-correlation energy in the strong-correlation limit to replace an equal fraction of the semi-local approximation to the exchange-correlation energy in the strong-correlation limit. The performance of the proposed approximations is evaluated for molecular atomization energies, total atomic energies, and ionization potentials
Determining the meson-nucleus potential - on the way to mesic states
Metag, Volker, E-mail: volker.metag@exp2.physik.uni-giessen.de [Universität Giessen, II. Physikalisches Institut (Germany)
2015-08-15
Experimental approaches to determine the real and imaginary part of the meson-nucleus potential are described. The experiments have been performed with the Crystal Barrel/TAPS detector at the electron accelerator ELSA (Bonn) and the Crystal Ball/TAPS detector at MAMI (Mainz). Measuring the transparency ratio as well as the excitation function and momentum distribution for photo production of ω and η′ mesons, the imaginary part of the η′-nucleus potential is found to be smaller than the real part. In case of the ω meson the opposite is observed. This makes the η′ meson a good candidate for the search for meson-nucleus bound states while no resolved ω mesic states can be expected. The results are discussed and compared to theoretical predictions. An outlook on future experiments is given.
Interference in Exclusive Vector Meson Production in Heavy-Ion Collisions
Klein, Spencer R.; Nystrand, Joakim
2000-01-01
Vector mesons are produced copiously in peripheral relativistic heavy-ion collisions. Virtual photons from one ion can fluctuate into quark-antiquark pairs and scatter from the second ion, emerging as vector mesons. The emitter and target are indistinguishable, so emission from the two ions will interfere. Vector mesons have negative parity so the interference is destructive, reducing the production of mesons with small transverse momentum. The mesons are short lived, and decay before emission from the two ions can overlap. However, the decay-product wave functions overlap and interfere since they are produced in an entangled state, providing an example of the Einstein-Podolsky-Rosen paradox. (c) 2000 The American Physical Society
Xie, Ya-Ping; Chen, Xurong
2018-05-01
Photoproduction of vector mesons is computed with dipole model in proton-proton ultraperipheral collisions (UPCs) at the CERN Large Hadron Collider (LHC). The dipole model framework is employed in the calculations of vector mesons production in diffractive processes. Parameters of the bCGC model are refitted with the latest inclusive deep inelastic scattering experimental data. Employing the bCGC model and boosted Gaussian light-cone wave function for vector mesons, we obtain the prediction of rapidity distributions of J/ψ and ψ(2s) mesons in proton-proton ultraperipheral collisions at the LHC. The predictions give a good description of the experimental data of LHCb. Predictions of ϕ and ω mesons are also evaluated in this paper.
Perspectives of Scalar- and Vector- Meson Production in Hadron-Nucleus Reactions
Cassing, W.
2000-01-01
The production and decay of vector mesons (ρ, ω) in pA reactions at COSY energies is studied with particular emphasis on their in-medium spectral functions. It is explored within transport calculations, if hadronic in-medium decays like π + π - or π 0 γ might provide complementary information to their dilepton (e + e - ) decays. Whereas the π + π - signal from the ρ-meson is found to be strongly distorted by pion rescattering, the ω- meson Dalitz decay to π 0 γ appears promising even for more heavy nuclei. The perspectives of scalar meson ( f 0 , a 0 ) production in pp reactions are investigated within a boson-exchange model indicating that the f 0 -meson might hardly be detected in these collisions in the K(anti)K or ππ decay channels whereas the exclusive channel pp→da 0 + looks very promising. (author)
Magnetic polarizabilities of light mesons in SU(3 lattice gauge theory
E.V. Luschevskaya
2015-09-01
Full Text Available We investigate the ground state energies of neutral pseudoscalar and vector meson in SU(3 lattice gauge theory in the strong abelian magnetic field. The energy of ρ0 meson with zero spin projection sz=0 on the axis of the external magnetic field decreases, while the energies with non-zero spins sz=−1 and +1 increase with the field. The energy of π0 meson decreases as a function of the magnetic field. We calculate the magnetic polarizabilities of pseudoscalar and vector mesons for lattice volume 184. For ρ0 with spin |sz|=1 and π0 meson the polarizabilities in the continuum limit have been evaluated. We do not observe any evidence in favour of tachyonic mode existence.
Danilov, G.S.
1995-01-01
A new formalism for ghosts on complex (1 bar 1) supermanifolds of genus n > 1 is discussed in superstring theory. In this formalism, vacuum correlation functions for ghost superfields differ substantially from correlation functions discussed earlier. In particular, the new correlation functions do not have unphysical poles. Among other things, these correlation functions take into account contributions to partition functions from the phase space of modular forms and from zero modes of ghosts. The above correlation functions, obtained for all even spinor structures, can be used to evaluate partition functions from equations that are nothing but Ward identities. 21 refs
Cafiero, Mauricio; Gonzalez, Carlos
2005-01-01
We show that potentials for exchange-correlation functionals within the Kohn-Sham density-functional-theory framework may be written as potentials for simpler functionals multiplied by a factor close to unity, and in a self-consistent field calculation, these effective potentials find the correct self-consistent solutions. This simple theory is demonstrated with self-consistent exchange-only calculations of the atomization energies of some small molecules using the Perdew-Kurth-Zupan-Blaha (PKZB) meta-generalized-gradient-approximation (meta-GGA) exchange functional. The atomization energies obtained with our method agree with or surpass previous meta-GGA calculations performed in a non-self-consistent manner. The results of this work suggest the utility of this simple theory to approximate exchange-correlation potentials corresponding to energy functionals too complicated to generate closed forms for their potentials. We hope that this method will encourage the development of complex functionals which have correct boundary conditions and are free of self-interaction errors without the worry that the functionals are too complex to differentiate to obtain potentials
Meson (photo- and) electro-production and the structure of nuclei at short distances
Laget, J.M.
1985-09-01
The present status and the future prospects of the studies of very inelastic electronuclear reaction are reviewed, when both high energy and high momentum are transferred to the nucleus. Real and virtual mesons are tested on the same footing. Real meson production allows us to study the propagation of baryonic and mesonic resonances in nuclei and to put constraints on their interaction with the nucleon. Virtual meson creation is an alternative way to deal with exchange currents. The first lecture deals with the elementary operators, which describe meson photo- and electroproduction on free nucleons. The second one deals with real meson- photo- and electroproduction on few-body systems. Only the main features are discussed here and the last developments are presented. The third lecture deals with the coupling of the electromagnetic probe to the virtual meson in nuclei. The emphasis is put on the few-body systems, since their nuclear wave functions are known and since they are simple enough to allow for elaborate calculations. The case of heavy nuclei is also discussed. In the last lecture, I will try to look for evidence of the limits and the breakdown of the description of nuclei in terms of nucleons and mesons, and to forecast the new developments
The Galaxy Count Correlation Function in Redshift Space Revisited
Campagne, J.-E.; Plaszczynski, S.; Neveu, J.
2017-08-01
In the near future, cosmology will enter the wide and deep galaxy survey era, enabling high-precision studies of the large-scale structure of the universe in three dimensions. To test cosmological models and determine their parameters accurately, it is necessary to use data with exact theoretical expectations expressed in observational parameter space (angles and redshift). The data-driven, galaxy number count fluctuations on redshift shells can be used to build correlation functions ξ (θ ,{z}1,{z}2) on and between shells to probe the baryonic acoustic oscillations and distance-redshift distortions, as well as gravitational lensing and other relativistic effects. To obtain a numerical estimation of ξ (θ ,{z}1,{z}2) from a cosmological model, it is typical to use either a closed form derived from a tripolar spherical expansion or to compute the power spectrum {C}{\\ell }({z}1,{z}2) and perform a Legendre polynomial {P}{\\ell }(\\cos θ ) expansion. Here, we present a new derivation of a ξ (θ ,{z}1,{z}2) closed form using the spherical harmonic expansion and proceeding to an infinite sum over multipoles thanks to an addition theorem. We demonstrate that this new expression is perfectly compatible with the existing closed forms but is simpler to establish and manipulate. We provide formulas for the leading density and redshift-space contributions, but also show how Doppler-like and lensing terms can be easily included in this formalism. We have implemented and made publicly available software for computing those correlations efficiently, without any Limber approximation, and validated this software with the CLASSgal code. It is available at https://gitlab.in2p3.fr/campagne/AngPow.
Temporal discrimination, a cervical dystonia endophenotype: penetrance and functional correlates.
Kimmich, Okka; Molloy, Anna; Whelan, Robert; Williams, Laura; Bradley, David; Balsters, Joshua; Molloy, Fiona; Lynch, Tim; Healy, Daniel G; Walsh, Cathal; O'Riordan, Seán; Reilly, Richard B; Hutchinson, Michael
2014-05-01
The pathogenesis of adult-onset primary dystonia remains poorly understood. There is variable age-related and gender-related expression of the phenotype, the commonest of which is cervical dystonia. Endophenotypes may provide insight into underlying genetic and pathophysiological mechanisms of dystonia. The temporal discrimination threshold (TDT)-the shortest time interval at which two separate stimuli can be detected as being asynchronous-is abnormal both in patients with cervical dystonia and in their unaffected first-degree relatives. Functional magnetic resonance imaging (fMRI) studies have shown that putaminal activation positively correlates with the ease of temporal discrimination between two stimuli in healthy individuals. We hypothesized that abnormal temporal discrimination would exhibit similar age-related and gender-related penetrance as cervical dystonia and that unaffected relatives with an abnormal TDT would have reduced putaminal activation during a temporal discrimination task. TDTs were examined in a group of 192 healthy controls and in 158 unaffected first-degree relatives of 84 patients with cervical dystonia. In 24 unaffected first-degree relatives, fMRI scanning was performed during a temporal discrimination task. The prevalence of abnormal TDTs in unaffected female relatives reached 50% after age 48 years; whereas, in male relatives, penetrance of the endophenotype was reduced. By fMRI, relatives who had abnormal TDTs, compared with relatives who had normal TDTs, had significantly less activation in the putamina and in the middle frontal and precentral gyri. Only the degree of reduction of putaminal activity correlated significantly with worsening of temporal discrimination. These findings further support abnormal temporal discrimination as an endophenotype of cervical dystonia involving disordered basal ganglia circuits. © 2014 International Parkinson and Movement Disorder Society.
Transport through correlated systems with density functional theory.
Kurth, S; Stefanucci, G
2017-10-18
We present recent advances in density functional theory (DFT) for applications in the field of quantum transport, with particular emphasis on transport through strongly correlated systems. We review the foundations of the popular Landauer-Büttiker(LB) + DFT approach. This formalism, when using approximations to the exchange-correlation (xc) potential with steps at integer occupation, correctly captures the Kondo plateau in the zero bias conductance at zero temperature but completely fails to capture the transition to the Coulomb blockade (CB) regime as the temperature increases. To overcome the limitations of LB + DFT, the quantum transport problem is treated from a time-dependent (TD) perspective using TDDFT, an exact framework to deal with nonequilibrium situations. The steady-state limit of TDDFT shows that in addition to an xc potential in the junction, there also exists an xc correction to the applied bias. Open shell molecules in the CB regime provide the most striking examples of the importance of the xc bias correction. Using the Anderson model as guidance we estimate these corrections in the limit of zero bias. For the general case we put forward a steady-state DFT which is based on one-to-one correspondence between the pair of basic variables, steady density on and steady current across the junction and the pair local potential on and bias across the junction. Like TDDFT, this framework also leads to both an xc potential in the junction and an xc correction to the bias. Unlike TDDFT, these potentials are independent of history. We highlight the universal features of both xc potential and xc bias corrections for junctions in the CB regime and provide an accurate parametrization for the Anderson model at arbitrary temperatures and interaction strengths, thus providing a unified DFT description for both Kondo and CB regimes and the transition between them.
Gubler, Philipp; Ohtani, Keisuke
2015-01-01
The modification of the ϕ-meson at finite density is studied by using QCD sum rules in combination with the maximum entropy method. As a result, it is found that the mass shift of the ϕ-meson is strongly correlated to the strangeness content of the nucleon, , which governs the depletion of the strange quark condensate in nuclear matter. (author)
Negative meson capture in hydrogen
Baird, T.J.
1977-01-01
The processes of deexcitation and capture of negative mesons and hadrons in atomic hydrogen are investigated. Only slow collisions in which the projectile-atom relative velocity is less than one atomic unit are considered, and the motion of the incident particle is treated classically. For each classical trajectory the probability of ionizing the hydrogen atom is determined, together with the energy spectrum of the emitted electron. Ionization probabilities are calculated using the time-dependent formulation of the perturbed stationary state method. Exact two-center electronic wave functions are used for both bound and continuum states. The total ionization cross section and electron energy spectrum have been calculated for negative muons, kaons and antiprotons at incident relative velocities between 0.04 and 1.0 atomic units. The electron energy spectrum has a sharp peak for electron kinetic energies on the order of 10 -3 Rydbergs. The ionization process thus favors the emission of very slow electrons. The cross section for ionization with capture of the incident particle was calculated for relative kinetic energies greater than 1.0 Rydberg. Since ionization was found to occur with the emission of electrons of nearly zero kinetic energy, the fraction of ionizing collisions which result in capture decreases very rapidly with projectile kinetic energy. The energy distributions of slowed down muons and hadrons were also computed. These distributions were used together with the capture cross section to determine the distribution of kinetic energies at which capture takes place. It was found that most captures occur for kinetic energies slightly less than 1.0 Rydbergs with relatively little capture at thermal energies. The captured particles therefore tend to go into very large and loosely found orbits with binding energies less than 0.1 Rydbergs
QCD bosonization and the meson effective action
Praschifka, J.; Roberts, C.D.; Cahill, R.T.
1987-01-01
A bosonization of quantum chromodynamics (QCD) is employed to derive a meson effective action, thus providing a direct link between QCD and meson phenomenology. As an example of this approach expressions are obtained for the meson parameters associated with the analysis of ω→3π decay. The bosonization also directly motivates a divergence-free, global color-symmetry model for mesons, which is seen to be a generalization of various phenomenological models. Good estimates are obtained for the values of several of the meson parameters
Spin-zero mesons and current algebras
Wellner, M.
1977-01-01
Large chiral algebras, using the f and d coefficients of SU(3) can be constructed with spin-1/2 baryons. Such algebras have been found useful in some previous investigations. This article examines under what conditions similar or identical current algebras may be realized with spin-0 mesons. A curious lack of analogy emerges between meson and baryon currents. Second-class currents, made of mesons, are required in some algebras. If meson and baryon currents are to satisfy the same extended SU(3) algebra, four meson nonets are needed, in terms of which we give an explicit construction for the currents
Neutral and charged scalar mesons, pseudoscalar mesons, and diquarks in magnetic fields
Liu, Hao; Wang, Xinyang; Yu, Lang; Huang, Mei
2018-04-01
We investigate both (pseudo)scalar mesons and diquarks in the presence of external magnetic field in the framework of the two-flavored Nambu-Jona-Lasinio (NJL) model, where mesons and diquarks are constructed by infinite sum of quark-loop chains by using random phase approximation. The polarization function of the quark-loop is calculated to the leading order of 1 /Nc expansion by taking the quark propagator in the Landau level representation. We systematically investigate the masses behaviors of scalar σ meson, neutral and charged pions as well as the scalar diquarks, with respect to the magnetic field strength at finite temperature and chemical potential. It is shown that the numerical results of both neutral and charged pions are consistent with the lattice QCD simulations. The mass of the charge neutral pion keeps almost a constant under the magnetic field, which is preserved by the remnant symmetry of QCD ×QED in the vacuum. The mass of the charge neutral scalar σ is around two times quark mass and increases with the magnetic field due to the magnetic catalysis effect, which is an typical example showing that the polarized internal quark structure cannot be neglected when we consider the meson properties under magnetic field. For the charged particles, the one quark-antiquark loop contribution to the charged π± increases essentially with the increase of magnetic fields due to the magnetic catalysis of the polarized quarks. However, the one quark-quark loop contribution to the scalar diquark mass is negative comparing with the point-particle result and the loop effect is small.
Choi, Ji Yeh; Hwang, Heungsun; Yamamoto, Michio; Jung, Kwanghee; Woodward, Todd S
2017-06-01
Functional principal component analysis (FPCA) and functional multiple-set canonical correlation analysis (FMCCA) are data reduction techniques for functional data that are collected in the form of smooth curves or functions over a continuum such as time or space. In FPCA, low-dimensional components are extracted from a single functional dataset such that they explain the most variance of the dataset, whereas in FMCCA, low-dimensional components are obtained from each of multiple functional datasets in such a way that the associations among the components are maximized across the different sets. In this paper, we propose a unified approach to FPCA and FMCCA. The proposed approach subsumes both techniques as special cases. Furthermore, it permits a compromise between the techniques, such that components are obtained from each set of functional data to maximize their associations across different datasets, while accounting for the variance of the data well. We propose a single optimization criterion for the proposed approach, and develop an alternating regularized least squares algorithm to minimize the criterion in combination with basis function approximations to functions. We conduct a simulation study to investigate the performance of the proposed approach based on synthetic data. We also apply the approach for the analysis of multiple-subject functional magnetic resonance imaging data to obtain low-dimensional components of blood-oxygen level-dependent signal changes of the brain over time, which are highly correlated across the subjects as well as representative of the data. The extracted components are used to identify networks of neural activity that are commonly activated across the subjects while carrying out a working memory task.
Kotulla, M
2006-01-01
We discuss recent experimental results on the modification of hadron properties in a nuclear medium. Particular emphasis is placed on an $\\omega$ production experiment performed by the CBELSA/TAPS collaboration at the ELSA accelerator. The data shows a smaller $\\omega$ meson mass together with a significant increase of its width in the nuclear medium.
Duong Van Phi; Duong Anh Duc
1992-12-01
The channels of the decay of Bottom mesons are deduced from a selection rule and the Lagrangians which are formed on the LxO(4) invariance and the principle of minimal structure. The estimation of the corresponding decay probabilities are considered. (author). 21 refs
Exclusive meson production at COMPASS
Pochodzalla, Josef; Moinester, Murray; Piller, Gunther; Sandacz, Andrzej; Vanderhaeghen, Marc; Pochodzalla, Josef; Mankiewicz, Lech; Moinester, Murray; Piller, Gunther; Sandacz, Andrzej; Vanderhaeghen, Marc
1999-01-01
We explore the feasibility to study exclusive meson production (EMP) in hard muon-proton scattering at the COMPASS experiment. These measurements constrain the off-forward parton distributions (OFPD's) of the proton, which are related to the quark orbital contribution to the proton spin.
Distribution amplitudes of vector mesons
Braun, V.M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Broemmel, D. [Deutsches Elektronen-Synchrotron, Hamburg (Germany); Goeckeler, M. [Regensburg Univ. (DE). Inst. fuer Theoretische Physik] (and others)
2007-11-15
Results are presented for the lowest moment of the distribution amplitude for the K{sup *} vector meson. Both longitudinal and transverse moments are investigated. We use two flavours of O(a) improved Wilson fermions, together with a non-perturbative renormalisation of the matrix element. (orig.)
A light meson translatable template
Allgower, C.E.; Peaslee, D.C.
2002-01-01
Recently surveyed (mass)2 values for I = 0, JPC = 2++ light mesons can be assembled into repeating patterns of 4 states, dubbed 'templates'. Within error, both internal and external template spacings approximate simple multiples of Δm2 ≅ 0.35 GeV2. Hopefully, this feature will be useful in predicting the positions of higher isoscalar 2++ states
Spline function fit for multi-sets of correlative data
Liu Tingjin; Zhou Hongmo
1992-01-01
The Spline fit method for multi-sets of correlative data is developed. The properties of correlative data fit are investigated. The data of 23 Na(n, 2n) cross section are fitted in the cases with and without correlation
Atmospheric stellar parameters from cross-correlation functions
Malavolta, L.; Lovis, C.; Pepe, F.; Sneden, C.; Udry, S.
2017-08-01
The increasing number of spectra gathered by spectroscopic sky surveys and transiting exoplanet follow-up has pushed the community to develop automated tools for atmospheric stellar parameters determination. Here we present a novel approach that allows the measurement of temperature (Teff), metallicity ([Fe/H]) and gravity (log g) within a few seconds and in a completely automated fashion. Rather than performing comparisons with spectral libraries, our technique is based on the determination of several cross-correlation functions (CCFs) obtained by including spectral features with different sensitivity to the photospheric parameters. We use literature stellar parameters of high signal-to-noise (SNR), high-resolution HARPS spectra of FGK main-sequence stars to calibrate Teff, [Fe/H] and log g as a function of CCF parameters. Our technique is validated using low-SNR spectra obtained with the same instrument. For FGK stars we achieve a precision of σ _{{T_eff}} = 50 K, σlog g = 0.09 dex and σ _{{{[Fe/H]}}} =0.035 dex at SNR = 50, while the precision for observation with SNR ≳ 100 and the overall accuracy are constrained by the literature values used to calibrate the CCFs. Our approach can easily be extended to other instruments with similar spectral range and resolution or to other spectral range and stars other than FGK dwarfs if a large sample of reference stars is available for the calibration. Additionally, we provide the mathematical formulation to convert synthetic equivalent widths to CCF parameters as an alternative to direct calibration. We have made our tool publicly available.
Integrable dissipative exclusion process: Correlation functions and physical properties
Crampe, N.; Ragoucy, E.; Rittenberg, V.; Vanicat, M.
2016-09-01
We study a one-parameter generalization of the symmetric simple exclusion process on a one-dimensional lattice. In addition to the usual dynamics (where particles can hop with equal rates to the left or to the right with an exclusion constraint), annihilation and creation of pairs can occur. The system is driven out of equilibrium by two reservoirs at the boundaries. In this setting the model is still integrable: it is related to the open XXZ spin chain through a gauge transformation. This allows us to compute the full spectrum of the Markov matrix using Bethe equations. We also show that the stationary state can be expressed in a matrix product form permitting to compute the multipoints correlation functions as well as the mean value of the lattice and the creation-annihilation currents. Finally, the variance of the lattice current is computed for a finite-size system. In the thermodynamic limit, it matches the value obtained from the associated macroscopic fluctuation theory.
On soft limits of large-scale structure correlation functions
Ben-Dayan, Ido; Konstandin, Thomas; Porto, Rafael A.; Sagunski, Laura
2014-11-01
We study soft limits of correlation functions for the density and velocity fields in the theory of structure formation. First, we rederive the (resummed) consistency conditions at unequal times using the eikonal approximation. These are solely based on symmetry arguments and are therefore universal. Then, we explore the existence of equal-time relations in the soft limit which, on the other hand, depend on the interplay between soft and hard modes. We scrutinize two approaches in the literature: The time-flow formalism, and a background method where the soft mode is absorbed into a locally curved cosmology. The latter has been recently used to set up (angular averaged) 'equal-time consistency relations'. We explicitly demonstrate that the time-flow relations and 'equal-time consistency conditions' are only fulfilled at the linear level, and fail at next-to-leading order for an Einstein de-Sitter universe. While applied to the velocities both proposals break down beyond leading order, we find that the 'equal-time consistency conditions' quantitatively approximates the perturbative results for the density contrast. Thus, we generalize the background method to properly incorporate the effect of curvature in the density and velocity fluctuations on short scales, and discuss the reasons behind this discrepancy. We conclude with a few comments on practical implementations and future directions.
A marked correlation function for constraining modified gravity models
White, Martin
2016-11-01
Future large scale structure surveys will provide increasingly tight constraints on our cosmological model. These surveys will report results on the distance scale and growth rate of perturbations through measurements of Baryon Acoustic Oscillations and Redshift-Space Distortions. It is interesting to ask: what further analyses should become routine, so as to test as-yet-unknown models of cosmic acceleration? Models which aim to explain the accelerated expansion rate of the Universe by modifications to General Relativity often invoke screening mechanisms which can imprint a non-standard density dependence on their predictions. This suggests density-dependent clustering as a `generic' constraint. This paper argues that a density-marked correlation function provides a density-dependent statistic which is easy to compute and report and requires minimal additional infrastructure beyond what is routinely available to such survey analyses. We give one realization of this idea and study it using low order perturbation theory. We encourage groups developing modified gravity theories to see whether such statistics provide discriminatory power for their models.
A marked correlation function for constraining modified gravity models
White, Martin, E-mail: mwhite@berkeley.edu [Department of Physics, University of California, Berkeley, CA 94720 (United States)
2016-11-01
Future large scale structure surveys will provide increasingly tight constraints on our cosmological model. These surveys will report results on the distance scale and growth rate of perturbations through measurements of Baryon Acoustic Oscillations and Redshift-Space Distortions. It is interesting to ask: what further analyses should become routine, so as to test as-yet-unknown models of cosmic acceleration? Models which aim to explain the accelerated expansion rate of the Universe by modifications to General Relativity often invoke screening mechanisms which can imprint a non-standard density dependence on their predictions. This suggests density-dependent clustering as a 'generic' constraint. This paper argues that a density-marked correlation function provides a density-dependent statistic which is easy to compute and report and requires minimal additional infrastructure beyond what is routinely available to such survey analyses. We give one realization of this idea and study it using low order perturbation theory. We encourage groups developing modified gravity theories to see whether such statistics provide discriminatory power for their models.
Short-range correlations with pseudopotentials
Osman, A.
1976-01-01
Short-range correlations in nuclei are considered on an unitary-model operator approach. Short-range pseudopotentials have been added to achieve healing in the correlated wave functions. With the introduction of the pseudopotentials, correlated basis wave functions are constructed. The matrix element for effective interaction in nuclei is developed. The required pseudopotentials have been calculated for the Hamda-Johnston, Yale and Reid potentials and for the nuclear nucleon-nucleon potential A calculated by us according to meson exchange between nucleons. (Osman, A.)
Mattsson, Ann E.; Wills, John M.
2013-03-01
The inability to computationally describe the physics governing the properties of actinides and their alloys is the poster child of failure of existing Density Functional Theory exchange-correlation functionals. The intricate competition between localization and delocalization of the electrons, present in these materials, exposes the limitations of functionals only designed to properly describe one or the other situation. We will discuss the manifestation of this competition in real materials and propositions on how to construct a functional able to accurately describe properties of these materials. I addition we will discuss both the importance of using the Dirac equation to describe the relativistic effects in these materials, and the connection to the physics of transition metal oxides. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
On soft limits of large-scale structure correlation functions
Sagunski, Laura
2016-08-01
Large-scale structure surveys have the potential to become the leading probe for precision cosmology in the next decade. To extract valuable information on the cosmological evolution of the Universe from the observational data, it is of major importance to derive accurate theoretical predictions for the statistical large-scale structure observables, such as the power spectrum and the bispectrum of (dark) matter density perturbations. Hence, one of the greatest challenges of modern cosmology is to theoretically understand the non-linear dynamics of large-scale structure formation in the Universe from first principles. While analytic approaches to describe the large-scale structure formation are usually based on the framework of non-relativistic cosmological perturbation theory, we pursue another road in this thesis and develop methods to derive generic, non-perturbative statements about large-scale structure correlation functions. We study unequal- and equal-time correlation functions of density and velocity perturbations in the limit where one of their wavenumbers becomes small, that is, in the soft limit. In the soft limit, it is possible to link (N+1)-point and N-point correlation functions to non-perturbative 'consistency conditions'. These provide in turn a powerful tool to test fundamental aspects of the underlying theory at hand. In this work, we first rederive the (resummed) consistency conditions at unequal times by using the so-called eikonal approximation. The main appeal of the unequal-time consistency conditions is that they are solely based on symmetry arguments and thus are universal. Proceeding from this, we direct our attention to consistency conditions at equal times, which, on the other hand, depend on the interplay between soft and hard modes. We explore the existence and validity of equal-time consistency conditions within and beyond perturbation theory. For this purpose, we investigate the predictions for the soft limit of the
On soft limits of large-scale structure correlation functions
Sagunski, Laura
2016-08-15
Large-scale structure surveys have the potential to become the leading probe for precision cosmology in the next decade. To extract valuable information on the cosmological evolution of the Universe from the observational data, it is of major importance to derive accurate theoretical predictions for the statistical large-scale structure observables, such as the power spectrum and the bispectrum of (dark) matter density perturbations. Hence, one of the greatest challenges of modern cosmology is to theoretically understand the non-linear dynamics of large-scale structure formation in the Universe from first principles. While analytic approaches to describe the large-scale structure formation are usually based on the framework of non-relativistic cosmological perturbation theory, we pursue another road in this thesis and develop methods to derive generic, non-perturbative statements about large-scale structure correlation functions. We study unequal- and equal-time correlation functions of density and velocity perturbations in the limit where one of their wavenumbers becomes small, that is, in the soft limit. In the soft limit, it is possible to link (N+1)-point and N-point correlation functions to non-perturbative 'consistency conditions'. These provide in turn a powerful tool to test fundamental aspects of the underlying theory at hand. In this work, we first rederive the (resummed) consistency conditions at unequal times by using the so-called eikonal approximation. The main appeal of the unequal-time consistency conditions is that they are solely based on symmetry arguments and thus are universal. Proceeding from this, we direct our attention to consistency conditions at equal times, which, on the other hand, depend on the interplay between soft and hard modes. We explore the existence and validity of equal-time consistency conditions within and beyond perturbation theory. For this purpose, we investigate the predictions for the soft limit of the
Anisotropic extinction distortion of the galaxy correlation function
Fang Wenjuan; Hui Lam; Menard, Brice; May, Morgan; Scranton, Ryan
2011-01-01
Similar to the magnification of the galaxies' fluxes by gravitational lensing, the extinction of the fluxes by comic dust, whose existence is recently detected by [B. Menard, R. Scranton, M. Fukugita, and G. Richards, Mon. Not. R. Astron. Soc. 405, 1025 (2010).], also modifies the distribution of a flux-selected galaxy sample. We study the anisotropic distortion by dust extinction to the 3D galaxy correlation function, including magnification bias and redshift distortion at the same time. We find the extinction distortion is most significant along the line of sight and at large separations, similar to that by magnification bias. The correction from dust extinction is negative except at sufficiently large transverse separations, which is almost always opposite to that from magnification bias (we consider a number count slope s>0.4). Hence, the distortions from these two effects tend to reduce each other. At low z (< or approx. 1), the distortion by extinction is stronger than that by magnification bias, but at high z, the reverse holds. We also study how dust extinction affects probes in real space of the baryon acoustic oscillations (BAO) and the linear redshift distortion parameter β. We find its effect on BAO is negligible. However, it introduces a positive scale-dependent correction to β that can be as large as a few percent. At the same time, we also find a negative scale-dependent correction from magnification bias, which is up to percent level at low z, but to ∼40% at high z. These corrections are non-negligible for precision cosmology, and should be considered when testing General Relativity through the scale-dependence of β.
submitter Time-dependent CP violation in charm mesons
Inguglia, Gianluca
CP violation is a well established phenomenon for B and K mesons, but for D0 mesons, bound states made up of a quark-antiquark pair containing a charm quark, a conclusive answer to the question whether there is CP vio- lation or not, has yet to be determined. I show here the phenomenology of time-dependent CP asymmetries in charm decays, and discuss the implica- tions of experimental tests aimed at the measurement of CP violation in the interference between mixing and decays of charm mesons, in particular when studying the decay channels D0 ! h+h (h = K; ). The decay channels considered can also be used to constrain quantities that are poorly measured or still to be investigated, such as MIX and c;eff , provided that the e ects of penguin pollution are ignored. I considered correlated production of D0 mesons at the SuperB experiment and its planned asymmetric run at the charm threshold and performed a study of simulated events, nding that a boost factor = 0:28 would not be su cient to produce competitive re- ...
Meson-Meson molecules and compact four-quark states
Vijande, J.; Valcarce, A.
2010-01-01
The physics of charm has become one of the best laboratories exposing the limitations of the naive constituent quark model and also giving hints into a more mature description of meson spectroscopy, beyond the simple quark-antiquark configurations. In this talk we review some recent studies of multiquark components in the charm sector and discuss in particular exotic and non-exotic four-quark systems.
Exotic meson decay widths using lattice QCD
Cook, M. S.; Fiebig, H. R.
2006-01-01
A decay width calculation for a hybrid exotic meson h, with J PC =1 -+ , is presented for the channel h→πa 1 . This quenched lattice QCD simulation employs Luescher's finite box method. Operators coupling to the h and πa 1 states are used at various levels of smearing and fuzzing, and at four quark masses. Eigenvalues of the corresponding correlation matrices yield energy spectra that determine scattering phase shifts for a discrete set of relative πa 1 momenta. Although the phase shift data is sparse, fits to a Breit-Wigner model are attempted, resulting in a decay width of about 60 MeV when averaged over two lattice sizes having a lattice spacing of 0.07 fm
ρ-meson self-energy and dielectron emissivity in an isospin-asymmetric pion medium
Titov, A.I.; Gulamov, T.I.; Kaempfer, B.
1996-01-01
The ρ-meson self-energy in an isospin-asymmetric pion gas at finite temperature and charged-pion chemical potential is evaluated. We utilize a conventional effective π-ρ Lagrangian and the functional integral representation of the partition function in the second order in the ρππ coupling constant. We analyze the ρ-meson polarization operator and its dependence on the invariant mass M and spatial momentum parallel p parallel of the ρ meson. The pole positions and the values of the imaginary parts of the self-energy for different polarization states have different functional dependences on M and parallel p parallel. The corresponding dielectron rate (calculated from the imaginary part of the in-medium ρ-meson propagator) shows a distinctive asymmetry when the momentum t=p + -p - is perpendicular or parallel to p, where p ± are the e ± momenta of the electron pair. copyright 1996 The American Physical Society
A chiral quark model for meson electroproduction in the S11 partial wave
Golli, B.; Sirca, S.
2011-01-01
We calculate the meson scattering and electroproduction amplitudes in the S11 partial wave in a coupled-channel approach that incorporates quasi-bound quark-model states. Using the quark wave functions and the quark-meson interaction from the Cloudy Bag Model, we obtain a good overall agreement with the available experimental results for the partial widths of the N(1535) and the N(1650) resonances as well as for the pion, eta and kaon electroproduction amplitudes. Our model is consistent with the N(1535) resonance being dominantly a genuine three-quark state rather than a quasi-bound state of mesons and baryons. (orig.)
Exclusive photoproduction of vector mesons in proton-lead ultraperipheral collisions at the LHC
Xie, Ya-Ping; Chen, Xurong
2018-02-01
Rapidity distributions of vector mesons are computed in dipole model proton-lead ultraperipheral collisions (UPCs) at the CERN Larger Hadron Collider (LHC). The dipole model framework is implemented in the calculations of cross sections in the photon-hadron interaction. The bCGC model and Boosted Gaussian wave functions are employed in the scattering amplitude. We obtain predictions of rapidity distributions of J / ψ meson proton-lead ultraperipheral collisions. The predictions give a good description to the experimental data of ALICE. The rapidity distributions of ϕ, ω and ψ (2 s) mesons in proton-lead ultraperipheral collisions are also presented in this paper.
Direct production of anti D0 mesons in neutrino-nucleon collisions
Onipchuk, A.B.; Choban, E.A.
1992-01-01
The inclusive production of anti D 0 mesons in neutrino-nucleon collisions is studied from the viewpoint of the quasiparton mechanism. The ratio R anti D 0 υ = σ(υ μ N → μ - X)/σ(υ μ N → μ - X), the kinematic distributions averaged over the υ μ spectrum, and the average kinematic characteristics of the final μ - and anti D 0 mesons are calculated. The number of events with anti D 0 -meson production is estimated as a function of the number of inclusive events
Decay of heavy mesons into possible spin 3/2 leptons
Carvalho, H.F. de; Antunes, A.C.B.
1982-01-01
The recent interest in the study of possible spin 3/2 leptons motivated our calculation of the decay rate of heavy mesons into these leptons. The mesons be upsilon UPSILON particles (bb sup(-) systems) or any other system of the qq sup(-) (quark-antiquark) kind with mass larger than those of the upsilon particles, for example, tt sup(-) bound states (not yet detected). The decay rate of these mesons is calculated as a function of the mass of the spin 3/2 leptons. The results obtained are compared with those of the spin 1/2 leptons. (Author) [pt
Measurement of Charm Meson Lifetimes
Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J.; Chan, S.; Eigen, G.; Lipeles, E.; Schmidtler, M.; Shapiro, A.; Sun, W.M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F.; Jaffe, D.E.; Masek, G.; Paar, H.P.; Potter, E.M.; Prell, S.; Sharma, V.; Asner, D.M.; Eppich, A.; Gronberg, J.; Hill, T.S.; Korte, C.M.; Lange, D.J.; Morrison, R.J.; Nelson, H.N.; Nelson, T.K.; Roberts, D.; Tajima, H.; Behrens, B.H.; Ford, W.T.; Gritsan, A.; Krieg, H.; Roy, J.; Smith, J.G.; Alexander, J.P.; Baker, R.; Bebek, C.; Berger, B.E.; Berkelman, K.; Boisvert, V.; Cassel, D.G.; Crowcroft, D.S.; Dickson, M.; Dombrowski, S. von; Drell, P.S.; Dumas, D.J.; Ecklund, K.M.; Ehrlich, R.; Foland, A.D.; Gaidarev, P.; Gibbons, L.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Hopman, P.I.; Katayama, N.; Kreinick, D.L.; Lee, T.; Liu, Y.; Meyer, T.O.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Ogg, M.; Patterson, J.R.; Peterson, D.; Riley, D.; Soffer, A.; Thayer, J.G.; Thies, P.G.; Valant-Spaight, B.; Warburton, A.; Ward, C.; Athanas, M.; Avery, P.; Jones, C.D.; Lohner, M.; Prescott, C.; Rubiera, A.I.; Yelton, J.; Zheng, J.; Brandenburg, G.; Briere, R.A.; Ershov, A.; Gao, Y.S.; Kim, D.Y.; Wilson, R.; Browder, T.E.; Li, Y.; Rodriguez, J.L.; Yamamoto, H.; Bergfeld, T.; Eisenstein, B.I.; Ernst, J.; Gladding, G.E.; Gollin, G.D
1999-01-01
We report measurements of the D 0 , D + , and D + s meson lifetimes using 3.7 fb -1 of e + e - annihilation data collected near the Υ(4S) resonance with the CLEO detector. The measured lifetimes of the D 0 , D + , and D + s mesons are 408.5±4.1 +3.5 -3.4 fs , 1033.6±22.1 +9.9 -12.7 fs , and 486.3±15.0 +4.9 -5.1 fs . The precision of these lifetimes are comparable to those of the best previous measurements, and the systematic errors are very different. In a single experiment we find that the ratio of the D + s and D 0 lifetimes is 1.19±0.04 . copyright 1999 The American Physical Society
Henley, E.M.
1998-01-01
One never quite knows what to say in a summary. If you were at the sessions, you heard the same talks I did. Perhaps the purpose is to summarize the parallel sessions, but like you, I can only attend one of these sessions. In addition, the time is short, so that this cannot be a real summary. What I will present are impressions of the past two days, and these will certainly be colored by my own views. Thus at the outset, let me apologize for any and all omissions and distortions. I will cover primarily the plenary session talks, but will organize this summary along the following lines: 1. vector (V) mesons; 2. pseudoscalar mesons, and 3. other subjects, notably with electrons. This afternoon's talks are so close in time to this summary that I shall omit them. (author)
Color superconductivity from the chiral quark-meson model
Sedrakian, Armen; Tripolt, Ralf-Arno; Wambach, Jochen
2018-05-01
We study the two-flavor color superconductivity of low-temperature quark matter in the vicinity of chiral phase transition in the quark-meson model where the interactions between quarks are generated by pion and sigma exchanges. Starting from the Nambu-Gorkov propagator in real-time formulation we obtain finite temperature (real axis) Eliashberg-type equations for the quark self-energies (gap functions) in terms of the in-medium spectral function of mesons. Exact numerical solutions of the coupled nonlinear integral equations for the real and imaginary parts of the gap function are obtained in the zero temperature limit using a model input spectral function. We find that these components of the gap display a complicated structure with the real part being strongly suppressed above 2Δ0, where Δ0 is its on-shell value. We find Δ0 ≃ 40MeV close to the chiral phase transition.
Feldman, G.J.
1977-01-01
A review is given of the nonleptonic decays of D mesons. Included are measurements of the psi(3772), the accurate determination of D masses and their consequences, and inclusive measurements and tagged events. It is noted that the distinction between the above designated events is that in the former one detects a D decay and ignores the remainder of the event, while in the tagged events a D decay is detected and also the remainder of the event is studied. 39 references
Correlation of Thyroid Functions with Severity and Outcome of ...
During normal pregnancy, changes in thyroid function are well documented; however, information regarding thyroid function in preeclampsia is scanty. Pregnancy is associated with increased total thyroxine (T4) and, in preeclampsia, biochemical hypothyroidism (raised thyroid‑stimulating hormone [TSH]) occurs.
Muoproduction of J/ψ-mesons and the gluon distribution in nucleons
Jong, Maarten de.
1991-01-01
The cross sections for production of J/ψ-mesons in muon-scattering at hydrogen and deuterium have been measured at a muon-energy of 280 GeV in order to extract from these the momentum distribution of gluons in the nucleon. These cross sections turned out to be equal for protons and neutrons within the experimental error. In the framework of the colour singlet model the gluon distribution has been determined from the cross section for the inelastic production of J/ψ mesons. At small gluon impulses the distribution obtained resembles a brems-strahlung spectrum. This distribution decreases, according to a simple description (counting rules) at larger impulses. The same model however underestimates the cross section for elastic production of J/ψ-mesons seriously. It is found that in inelastic production of J/ψ-mesons both helicities of the meson occur equally. Also a correlation has been observed between the scattering plane and the plane in which the J/ψ meson decays. The production of J/ψ-mesons and ψ'-mesons has been investigated in muon scattering at concrete at the same incoming energy. The measured ratio of their cross sections agrees with the colour singlet model but disagrees with the simplified description which characterizes the 'photon-gluon fusion model'. The possible nuclear-mass dependence of the cross section for J/ψ-meson production has been investigated in interactions of muons with tin and carbon at an energy of 280 GeV. This possible dependence turns out to be absent which means that on the basis of the colour singlet model the distributions of the gluons in the nucleon are equal in tin and carbon. (author). 103 refs.; 60 figs.; 19 tabs
High transverse momentum phenomena involving π and eta mesons
Buesser, F.W.; Camilleri, L.; Di Lella, L.
1975-01-01
The inclusive production of π and eta mesons at theta/sub cm/ = 90 0 was measured for proton-proton collisions at five center-of-mass energies between 23.5 and 62.4 GeV. The momentum correlation of charged particles emitted together with a large transverse momentum π was also studied using two magnetic spectrometers each centered at theta/sub cm/ = 90 0
Light tetraquarks and mesons in a DSE/BSE approach
Heupel, Walter
2015-07-01
are of a dynamical nature and are not put in by hand. Additionally, these two-body poles in the four-body equation can be interpreted as connection between the more fundamental four-body picture, where four quarks bind together, and the two-body picture, where the tetraquark is pictured as a bound state of two mesons and/or diquarks. In accordance with previous studies in a two-body framework, the pion-pion correlations are found to be much more dominant than the diquark-diquark correlations. Guided by the result that the tetraquark is dominated by poles in the phase space, an explicit pole ansatz for the amplitude was constructed, improving the numerical stability considerably. Subsequently, the Bethe-Salpeter equation was solved for tetraquarks with the quantum numbers 0++. For physical u/d-quark masses, the masses of the σ(0.35 GeV), κ(0.64 GeV) and the f{sub 0}/a{sub 0}(0.89 GeV) were calculated, with the corresponding masses given in brackets. Compared with the values of the experimental candidates, the masses are generically too low, probably caused by truncation artifacts. Nonetheless, according to the success of the Maris-Tandy model to describe ground state properties of mesons and baryons, the result is a strong indication that the lowest scalar nonet has indeed a considerable tetraquark component. Investigating the quark mass dependence of the sigma, candidates for an all strange tetraquark around 1.6 GeV and an all charm tetraquark around 5.7 GeV were found. These findings agree qualitatively with former results from a two-body approach. Additionally, the mass curve features an interesting cusp at a quark mass of about 0.65 GeV. Such cusps are known in the literature to be related to whether the T-matrix pole corresponds to a bound-state, a resonance or a virtual state. Part II: Following the time-honored concept of taking functional derivatives to obtain an interaction kernel, this technique is extended to vertex models which explicitly depend on the
Old tensor mesons in QCD sum rules
Aliev, T.M.; Shifman, M.A.
1981-01-01
Tensor mesons f, A 2 and A 3 are analyzed within the framework of QCD sum rules. The effects of gluon and quark condensate is accounted for phenomenologically. Accurate estimates of meson masses and coupling constants of the lowest-lying states are obtained. It is shown that the masses are reproduced within theoretical uncertainty of about 80 MeV. The coupling of f meson to the corresponding quark current is determined. The results are in good aqreement with experimental data [ru
Single spin asymmetry for charm mesons
Dominguez Zacarias, G. [PIMAyC, Eje Central Lazaro Cardenas No. 152, Apdo. Postal 14-805, D.F. (Mexico); Herrera, G.; Mercado, J. [Centro de Investigacion y de Estudios Avanzados, Apdo. Postal 14-740, D.F. (Mexico)
2007-08-15
We study single spin asymmetries of D{sup 0} and D{sup -} mesons in polarized proton-proton collisions. A two component model is used to describe charm meson production. The production of D mesons occurs by recombination of the constituents present in the initial state as well as by fragmentation of quarks in the final state. This model has proved to describe the production of charm. The recombination component involves a mechanism of spin alignment that ends up in a single spin asymmetry. Experimental measurements of single spin asymmetry for pions at RHIC are compared with the model. Predictions for the asymmetry in D mesons are presented. (orig.)
Single spin asymmetry for charm mesons
Dominguez Zacarias, G.; Herrera, G.; Mercado, J.
2007-01-01
We study single spin asymmetries of D 0 and D - mesons in polarized proton-proton collisions. A two component model is used to describe charm meson production. The production of D mesons occurs by recombination of the constituents present in the initial state as well as by fragmentation of quarks in the final state. This model has proved to describe the production of charm. The recombination component involves a mechanism of spin alignment that ends up in a single spin asymmetry. Experimental measurements of single spin asymmetry for pions at RHIC are compared with the model. Predictions for the asymmetry in D mesons are presented. (orig.)
Structurofunctional resting-state networks correlate with motor function in chronic stroke
Benjamin T. Kalinosky
2017-01-01
Conclusion: The results demonstrate that changes after a stroke in both intrinsic and network-based structurofunctional correlations at rest are correlated with motor function, underscoring the importance of residual structural connectivity in cortical networks.
Studies in the method of correlated basis functions. Pt. 3
Krotscheck, E.; Clark, J.W.
1980-01-01
A variational theory of pairing phenomena is presented for systems like neutron matter and liquid 3 He. The strong short-range correlations among the particles in these systems are incorporated into the trial states describing normal and pair-condensed phases, via a correlation operator F. The resulting theory has the same basic structure as that ordinarily applied for weak two-body interactions; in place of the pairing matrix elements of the bare interaction one finds certain effective pairing matrix elements Psub(kl), and modified single particle energies epsilon (k) appear. Detailed prescriptions are given for the construction of the Psub(kl) and epsilon (k) in terms of off-diagonal and diagonal matrix elements of the Hamiltonian and unit operators in a correlated basis of normal states. An exact criterion for instability of the assumed normal phase with respect to pair condensation is derived for general F. This criterion is investigated numerically for the special case if Jastrow correlations, the required normal-state quantities being evaluated by integral equation techniques which extend the Fermi hypernetted-chain scheme. In neutron matter, an instability with respect to 1 S 0 pairing is found in the low-density region, in concert with the predictions of Yang and Clark. In liquid 3 He, there is some indication of a 3 P 0 pairing instability in the vicinity of the experimental equilibrium density. (orig.)
Two Point Correlation Functions for a Periodic Box-Ball System
Jun Mada
2011-03-01
Full Text Available We investigate correlation functions in a periodic box-ball system. For the second and the third nearest neighbor correlation functions, we give explicit formulae obtained by combinatorial methods. A recursion formula for a specific N-point functions is also presented.
Arsić Slađana
2016-01-01
Full Text Available Introduction. It has been assumed that there is causality of the achieved level of functional independence with the degree of preservation of cognitive function in stroke patients. Demographic characteristics may be important for monitoring the achieved level of functional independence. Objective. The aim of this study was to examine the relationship of demographic characteristics and functional independence in regard to the level of cognitive impairment in stroke patients. Methods. The study included 50 stroke patients after rehabilitation, as well as age- and gender-matched 50 subjects selected randomly, according to the demographic characteristics of the studied sample, who in their medical history had no neurological disorders. For the assessment of functional independence, the Functional Independence Measure (FIM test was used. The general cognition was estimated by the Mini-Mental State Examination (MMSE test. The statistical analyses included the Mann-Whitney test, for two independent samples, measures of canonical correlation, and χ2 test. Results. There was a statistically significant difference between the groups in relation to risk factors, hypertension and diabetes mellitus type II (p<0.001; There was a statistically significant difference within the groups in relation to the cognitive impairment in all the examined demographic characteristics (p<0.001; the differences within the groups in relation to the cognitive impairment are present on all subscales of the FIM test (p<0.05; the differences within the groups in relation to handedness, hemiparesis, show that mild cognitive impairment is more common among left hemiparesis, while a more severe one is more common among right-sided hemiparesis (p<0.05; More severe cognitive impairment is common among women, the elderly and in persons with lower education (p<0.05. Conclusion. By prevention of risk factors, and prevention of possible cognitive impairment, consequences of stroke can be
Hilger, Thomas Uwe
2012-04-11
The interplay of hadron properties and their modification in an ambient nuclear medium on the one hand and spontaneous chiral symmetry breaking and its restoration on the other hand is investigated. QCD sum rules for D and B mesons embedded in cold nuclear matter are evaluated. We quantify the mass splitting of D- anti D and B- anti B mesons as a function of the nuclear matter density and investigate the impact of various condensates in linear density approximation. The analysis also includes D{sub s} and D{sup *}{sub 0} mesons. QCD sum rules for chiral partners in the open-charm meson sector are presented at nonzero baryon net density or temperature. We focus on the differences between pseudo-scalar and scalar as well as vector and axial-vector D mesons and derive the corresponding Weinberg type sum rules. Based on QCD sum rules we explore the consequences of a scenario for the ρ meson, where the chiral symmetry breaking condensates are set to zero whereas the chirally symmetric condensates remain at their vacuum values. The complementarity of mass shift and broadening is discussed. An alternative approach which utilizes coupled Dyson-Schwinger and Bethe-Salpeter equations for quark-antiquark bound states is investigated. For this purpose we analyze the analytic structure of the quark propagators in the complex plane numerically and test the possibility to widen the applicability of the method to the sector of heavy-light mesons in the scalar and pseudo-scalar channels, such as the D mesons, by varying the momentum partitioning parameter. The solutions of the Dyson-Schwinger equation in the Wigner-Weyl phase of chiral symmetry at nonzero bare quark masses are used to investigate a scenario with explicit but without dynamical chiral symmetry breaking.
Correlation function of four spins in the percolation model
Vladimir S. Dotsenko
2016-10-01
It is known that the four-point functions define the actual fusion rules of a particular model. In this respect, we find that fusion of two spins, of dimension Δσ=596, produce a new channel, in the 4-point function, which is due to the operator with dimension Δ=5/8.
Hierarchical structure of correlation functions for single jets
Lupia, S.; Giovannini, A.; Ugoccioni, R.
1993-01-01
Theoretical basis of void scaling function properties of hierarchical structure in rapidity and p T intervals are explored. Their phenomenological consequences are analyzed at single jet level by using Monte Carlo methods in e + e - annihilation. It is found that void scaling function study provides an interesting alternative approach for characterizing single jets of different origin. (orig.)
Hierarchical structure of correlation functions for single jets
Lupia, S. (Dipt. di Fisica Teorica, Univ. di Torino, and INFN, Sezione di Torino (Italy)); Giovannini, A. (Dipt. di Fisica Teorica, Univ. di Torino, and INFN, Sezione di Torino (Italy)); Ugoccioni, R. (Dipt. di Fisica Teorica, Univ. di Torino, and INFN, Sezione di Torino (Italy))
1993-08-01
Theoretical basis of void scaling function properties of hierarchical structure in rapidity and p[sub T] intervals are explored. Their phenomenological consequences are analyzed at single jet level by using Monte Carlo methods in e[sup +]e[sup -] annihilation. It is found that void scaling function study provides an interesting alternative approach for characterizing single jets of different origin. (orig.)
Huang, K.-N.
1977-01-01
A computational procedure for calculating correlated wave functions is proposed for three-particle systems interacting through Coulomb forces. Calculations are carried out for the muonic helium atom. Variational wave functions which explicitly contain interparticle coordinates are presented for the ground and excited states. General Hylleraas-type trial functions are used as the basis for the correlated wave functions. Excited-state energies of the muonic helium atom computed from 1- and 35-term wave functions are listed for four states.
Mcclelland, J.; Silk, J.
1978-01-01
Higher-order correlation functions for the large-scale distribution of galaxies in space are investigated. It is demonstrated that the three-point correlation function observed by Peebles and Groth (1975) is not consistent with a distribution of perturbations that at present are randomly distributed in space. The two-point correlation function is shown to be independent of how the perturbations are distributed spatially, and a model of clustered perturbations is developed which incorporates a nonuniform perturbation distribution and which explains the three-point correlation function. A model with hierarchical perturbations incorporating the same nonuniform distribution is also constructed; it is found that this model also explains the three-point correlation function, but predicts different results for the four-point and higher-order correlation functions than does the model with clustered perturbations. It is suggested that the model of hierarchical perturbations might be explained by the single assumption of having density fluctuations or discrete objects all of the same mass randomly placed at some initial epoch.
Jager, H.U.; Kirchbach, M.; Truhlik, E.
1982-01-01
Starting with the hard pion model based on a minimal chiral invariant phenomenological Lagrangian, the two-particle part of the time component of the weak axial-vector current is constructed in the tree-approximation. Pion, rho- and A 1 -meson exchanges are considered. The mesonic exchange operator obtained is applied to describe the purely weak axial 0 + reversible 0 - , ΔT=1 transition in the nuclear A=16 system the muon reaction μ - + 16 O(0 1 + ; T=0) → 16 N(0 1 - ; T=1) + γsub(μ) and beta decay 16 N(0 1 - ; T=1) → 16 O(0 1 + ; T=0) + e - + anti νsub(e). In order to treat nufar structure correlation efects explicit use of shell model wave functions with configuration mixing is made. The large enhancement of the nuclear weak axial charge density with respect to impulse approximation is established
Development of Colle-Salvetti type electron-nucleus correlation functional for MC-DFT
Udagawa, Taro [Department of Chemistry and Biomolecuar Science, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu 501-1193 (Japan); Tsuneda, Takao [Fuel Cell Nanomaterials Center, University of Yamanashi, Miyamae-cho 6-43, Kofu 400-0021 (Japan); Tachikawa, Masanori [Quqnatum Chemistry Division, Graduate School of Science, Yokohama City University, Seto 22-2, Kanazawa, Yokohama 236-0027 (Japan)
2015-12-31
A Colle-Salvetti type electron-nucleus correlation functional for multicomponent density-functional theory is proposed. We demonstrate that our correlation functional quantitatively reproduces the quantum nuclear effects of protons; the mean absolute deviation value is 2.8 millihartrees for the optimized structure of hydrogen-containing molecules. We also show other practical calculations with our new electron-deuteron and electron-triton correlation functionals. Since this functional is derived without any unphysical assumption, the strategy taken in this development will be a promising recipe to make new functionals for the potentials of other particles’ interactions.
Composite mesons in self-confining chiral solitons
Tandy, P.C.; Frank, M.R.
1991-01-01
Most quark-meson models for formation of a baryon as a bag or soliton solution begin with elementary local meson fields including a classical scalar configuration that provides repulsion of valence quarks from the vacuum. This presentation explores aspects of the very different formation mechanism that operates in a model where chiral effective meson fields are composite objects generated from bilocal qq-bar fluctuation fields and the dynamical quark mass can be self-confining. The focus is on the dynamical self-energy for quarks and the related distributed vertex for quark meson coupling. Initial numerical work to explore the practical consequences of these features is presented in the context of a static mean-field soliton. The particular method employed to identify the energy functional at the mean field or Hartree level is to obtain the standard effective action from the Legendre transformation with the help of a chemical potential constraint for the baryon number. The purpose of this approach is two-fold. First, a possible future consideration of radiative corrections might be undertaken by systematically continuing with the loop expansion beyond the lowest level. A second, more practical reason, is that in the presence of a general space-time dependent dynamical self-energy for quarks there are wavefunction renormalisation effects and energy self-consistencies to be defined and maintained for the valence quark states and eigenvalues. Speculations are made on whether this point of view can motivate meson-nucleon relativistic field models containing intrinsic cutoffs for use in nuclear physics. 29 refs., 5 figs
Search for Popcorn Mesons in Events with Two Charmed Baryons
Hartfiel, Brandon; /SLAC
2006-07-07
The physics of this note is divided into two parts. The first part measures the {Lambda}{sub c} {yields} {pi}kp continuum momentum spectrum at a center of mass energy of 10.54 GeV/c. The data sample consists of 15,400 {Lambda}{sub c} baryons from 9.46 fb{sup -1} of integrated luminosity. With more than 13 times more data than the best previous measurement, we are able to exclude some of the simpler, one parameter fragmentation functions. In the second part, we add the {Lambda}{sub c} {yields} K{sup 0}p mode, and look for events with a {Lambda}{sub c}{sup +} and a {bar {Lambda}}{sub c}{sup -} in order to look for ''popcorn'' mesons formed between the baryon and antibaryon. We add on-resonance data, with a kinematic cut to eliminate background from B decays, as well as BaBar run 3 and 4 data to increase the total data size to 219.70 fb{sup -1}. We find 619 events after background subtraction. After a subtraction of 1.06 {+-} .09 charged pions coming from decays of known resonances to {Lambda}{sub c} + {eta}{pi}, we are left with 2.63 {+-} .21 additional charged pions in each of these events. This is significantly higher than the .5 popcorn mesons per baryon pair used in the current tuning of Pythia 6.2, the most widely used Monte Carlo generator. The extra mesons we find appear to be the first direct evidence of popcorn mesons, although some of them could be arising from hypothetical unresolved, unobserved charmed baryon resonances contributing decay mesons to our data. To contribute a significant fraction, this hypothesis requires a large number of such broad unresolved states and seems unlikely, but can not be completely excluded.
A canonical correlation neural network for multicollinearity and functional data.
Gou, Zhenkun; Fyfe, Colin
2004-03-01
We review a recent neural implementation of Canonical Correlation Analysis and show, using ideas suggested by Ridge Regression, how to make the algorithm robust. The network is shown to operate on data sets which exhibit multicollinearity. We develop a second model which not only performs as well on multicollinear data but also on general data sets. This model allows us to vary a single parameter so that the network is capable of performing Partial Least Squares regression (at one extreme) to Canonical Correlation Analysis (at the other)and every intermediate operation between the two. On multicollinear data, the parameter setting is shown to be important but on more general data no particular parameter setting is required. Finally, we develop a second penalty term which acts on such data as a smoother in that the resulting weight vectors are much smoother and more interpretable than the weights without the robustification term. We illustrate our algorithms on both artificial and real data.
A variational determination of multi-time correlation functions
Balian, R.
1993-01-01
The purpose of this course is to present the general features of a work recently achieved with Marcel Veneroni. Part of the methods and results were already published in previous articles, but a synthesis has now been made, and a coherent though flexible scheme for evaluating correlations has emerged. We shall illustrate the approach by an example which leads to an elaborate extension of the mean-field theory for interacting fermions. Application to finite temperatures field theories may also be considered. (author)
Illusory correlation: a function of availability or representativeness heuristics?
MacDonald, M G
2000-08-01
The present study sought to investigate the illusory correlation phenomenon by experimentally manipulating the availability of information through the use of the "lag" effect (Madigan, 1969). Seventy-four university students voluntarily participated in this study. Similar to Starr and Katkin's (1969) methodology, subjects were visually presented with each possible combination of four experimental problem descriptions and four sentence completions that were paired and shown twice at each of four lags (i.e., with 0, 2, 8 and 20 intervening variables). Subjects were required to make judgements concerning the frequency with which sentence completions and problem descriptions co-occurred. In agreement with previous research (Starr & Katkin, 1969), the illusory correlation effect was found for specific descriptions and sentence completions. Results also yielded a significant effect of lag for mean ratings between 0 and 2 lags; however, there was no reliable increase in judged co-occurrence at lags 8 and 20. Evidence failed to support the hypothesis that greater availability, through the experimental manipulation of lag, would result in increased frequency of co-occurrence judgements. Findings indicate that, in the present study, the illusory correlation effect is probably due to a situational bias based on the representativeness heuristic.
Correlation functions of heisenberg-mattis model in one dimension
Azeeem, W.
1991-01-01
The technique of real-space renormalization to the dynamics of Heisenberg-Mattis model, which represents a random magnetic system with competing ferromagnetic and antiferromagnetic interactions has been applied. The renormalization technique, which has been in use for calculating density of states, is extended to calculate dynamical response function from momentum energy dependent Green's functions. Our numerical results on density of states and structure function of one-dimensional Heisenberg-Mattis model come out to be in good agreement with computer simulation results. The numerical scheme worked out in this thesis has the advantage that it can also provide a complete map of momentum and energy dependence of the structure function. (author)
On minimizing the influence of the noise tail of correlation functions in operational modal analysis
Tarpø, Marius; Olsen, Peter; Amador, Sandro
2017-01-01
on the identification results (random errors) when the noise tail is included in the identification. On the other hand, if the correlation function is truncated too much, then important information is lost. In other to minimize this error, a suitable truncation based on manual inspection of the correlation function......In operational modal analysis (OMA) correlation functions are used by all classical time-domain modal identification techniques that uses the impulse response function (free decays) as primary data. However, the main difference between the impulse response and the correlation functions estimated...... from the operational responses is that the latter present a higher noise level. This is due to statistical errors in the estimation of the correlation function and it causes random noise in the end of the function and this is called the noise tail. This noise might have significant influence...
Strange baryons in a chiral quark-meson model. Pt. 2
McGovern, J.A.; Birse, M.C.
1990-01-01
The chrial-quark meson model is used to study baryon properties with realistic breaking of SU(3). The symmetry breaking is assumed to be strong, so that a random phase approximation (RPA) can be used. In this the strange baryons are described as excitations built on the hedgehog soliton and have an excitation energy of 315 MeV. Other properties of strange baryons are obtained by an approximate spin-isospin projection from the RPA wave function. The magnetic moments agree reasonably well with experiment, but the deviations from the experimental values suggest that the method is valid for the case of rather stronger symmetry breaking than is realistic. The dependence of the RPA energy on the magnitude of the symmetry breaking is examined, and found to be strongly nonlinear for realistic values. This supports the idea that a large πN sigma commutator need not imply a large strange-quark content in the proton. For reasonable values of the scalar meson masses the strange-quark condensate is found to be less than 5% of the total, at the mean-field level. We also estimate the contribution to the condensate from RPA correlations. Within a one-mode approximation we find these to be very small, ≅ 2%. (orig.)
Topics on CP violation in B-meson decays
Soares, J.M.
1993-01-01
In this work several independent topics on CP violation in the B-meson decays are addressed. To begin with, the present constraints on the parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix are discussed. Then, I calculate the CP-violating asymmetry in the radiative decays of the charged B-mesons: it only appears at the 2-loop level, but it can be large in the b → dγ decays. At this point, the possibility of using these decays to measure the CKM entry |V td | will be studied. I also consider the decays of the neutral B-mesons: the strong correlation between the asymmetries in B 0 → ΨK S and the B 0 → π + π - is suggested as a powerful test of the standard model (a simple extension of the model is given where the correlation disappears). Finally, I address the question of observing direct CP violation in comparing these two asymmetries. An ambiguity that may arise is resolved due to the role that is played by penguin diagram contributions to the decay amplitudes
Exotic hybrid mesons in hard electroproduction
Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.
2005-01-01
We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC =1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e., as 1/Q 2 . This is due to the nonvanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy-momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in α S and we explore the consequences of fixing the renormalization scale ambiguity through the Brodsky-Lepage-Mackenzie (BLM) procedure. We study the particular case where the hybrid meson decays through a πη meson pair. We discuss the πη generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of π and η mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very high energy, in the diffractive limit where a QCD Odderon exchange mechanism should dominate. The conclusion of our study is that hard electroproduction is a promising way to study exotic hybrid mesons, in particular, at JLAB, HERA (HERMES), or CERN (Compass)
Experimental evidence for hadroproduction of exotic mesons
G. S. Adams; T. Adams; Z. Bar-Yam; J. M. Bishop; V. A. Bodyagin; B. B. Brabson; D. S. Brown; N. M. Cason; S. U. Chung; R. R. Crittenden; J. P. Cummings; K. Danyo; S. Denisov; V. Dorofeev; J. P. Dowd; A. R. Dzierba; P. Eugenio; J. Gunter; R. W. Hackenburg; M. Hayek; E. I. Ivanov; I. Kachaev; W. Kern; E. King; O. L. Kodolova; V. L. Korotkikh; M. A. Kostin; J. Kuhn; R. Lindenbusch; V. Lipaev; J. M. LoSecco; J. J. Manak; J. Napolitano; M. Nozar; C. Olchanski; A. I. Ostrovidov; T. K. Pedlar; A. Popov; D. R. Rust; D. Ryabchikov; A. H. Sanjari; L. I. Sarycheva; E. Scott; K. K. Seth; N. Shenhav; W. D. Shephard; N. B. Sinev; J. A. Smith; P. T. Smith; D. L. Stienike; T. Sulanke; S. A. Taegar; S. Teige; D. R. Thompson; I. N. Vardanyan; D. P. Weygand; D. White; H. J. Willutzki; J. Wise; M. Witkowski; A. A. Yershov; D. Zhao
2001-01-01
New measurements of peripheral meson production are presented. The data confirm the existence of exotic mesons at 1.4 and 1.6 GeV/c2. The latter state dominates the eta'pi- decay spectrum. The data on eta pi+pi-pi- decay show large strength in several exotic (Jpc = 1- +) waves as well
Experiments on eta-meson production
Peng, J.C.
1985-01-01
Following a review of some highlights of eta-meson characteristics, the status of eta-meson production experiments is reviewed. The physics motivations and first results of two LAMPF experiments on (π,eta) reactions are discussed. Possible future experiments are also discussed. 42 refs., 12 figs., 4 tabs
Review of meson resonance radiative decays
Thorndike, E.H.
1977-01-01
The radiative decays of meson resonances can be studied by three different approaches, it is noted. These are the meson-exchange, Primakoff effect, and the production of the desired resonance and subsequent observation of its decay. These approaches are criticized and examples of them are reviewed. Mass distributions are shown and branching ratios discussed. 21 references
The Bell inequality and correlation of spin projection functions
Andreev, V A
2009-01-01
The Bell inequality two-particle spin states are considered. It is shown that violation of this inequality at experimental verifications is connected with the fact that it is proved for some arbitrary random variables, but in experimental verification random variables of special type are used. A new inequality is constructed. It contains a correlation coefficient of random variables, measured at the experiment, and does not have to be violated at experimental verification. For factorizable and separable states it coincides with the usual Bell inequality.
Aldegunde, Manuel, E-mail: M.A.Aldegunde-Rodriguez@warwick.ac.uk; Kermode, James R., E-mail: J.R.Kermode@warwick.ac.uk; Zabaras, Nicholas
2016-04-15
This paper presents the development of a new exchange–correlation functional from the point of view of machine learning. Using atomization energies of solids and small molecules, we train a linear model for the exchange enhancement factor using a Bayesian approach which allows for the quantification of uncertainties in the predictions. A relevance vector machine is used to automatically select the most relevant terms of the model. We then test this model on atomization energies and also on bulk properties. The average model provides a mean absolute error of only 0.116 eV for the test points of the G2/97 set but a larger 0.314 eV for the test solids. In terms of bulk properties, the prediction for transition metals and monovalent semiconductors has a very low test error. However, as expected, predictions for types of materials not represented in the training set such as ionic solids show much larger errors.
Studies of Excited $D$ mesons in $B$ meson decays
AUTHOR|(CDS)2082679
This thesis documents the studies of several three-body B + meson decays, each with a charged charmed meson in the final state. All analyses presented use a data sample recorded by the LHCb detector in 2011 and 2012, corresponding to an integrated luminosity of 3.0 $fb^{-1}$ of $pp$ collision data. The $B^{+} \\to D^{-}K^{+}\\pi^{+}$ and $B^{+} \\to D^{+}K^{+}\\pi^{-}$ decay modes are observed for the first time. The branching fraction of the favoured $B^{+} \\to D^{-}K^{+}\\pi^{+}$ decay mode is measured relative to the topologically similar $B^{+} \\to D^{-}\\pi^{+}\\pi^{+}$ decay and the $B^{+} \\to D^{-}K^{+}\\pi^{+}$ final state is used as a normalisation channel for the suppressed $B^{+} \\to D^{+}K^{+}\\pi^{-}$ decay branching fraction measurement. Searches are performed for the quasi-two-body decays $B^{+} \\to D^{+}K^{*}(892)^{0}$ and $B^{+} \\to D_{2}^{*}(2460)^{0}K^{+}$, using the sample of $B^{+} \\to D^{+}K^{+}\\pi^{-}$ candidate decays. No significant signals are observed for either decay mode and upper limits a...
Hadronic spectral functions in nuclear matter
Post, M.; Leupold, S.; Mosel, U.
2004-01-01
We study the in-medium properties of mesons (π,η,ρ) and baryon resonances in cold nuclear matter within a coupled-channel analysis. The meson self energies are generated by particle-hole excitations. Thus multi-peak spectra are obtained for the mesonic spectral functions. In turn this leads to medium-modifications of the baryon resonances. Special care is taken to respect the analyticity of the spectral functions and to take into account effects from short-range correlations both for positive and negative parity states. Our model produces sensible results for pion and Δ dynamics in nuclear matter. We find a strong interplay of the ρ meson and the D 13 (1520), which moves spectral strength of the ρ spectrum to smaller invariant masses and leads to a broadening of the baryon resonance. The optical potential for the η meson resulting from our model is rather attractive whereas the in-medium properties modifications of the S 11 (1535) are found to be quite small
Sarmento, E.F.
1981-01-01
Results are found for the dynamical correlation functions (or its corresponding Green's functions) among any combination including operator pairs of electronic and nuclear spins in an antiferromagnet semi-infinite medium, at low temperatures T [pt
Vector mesons and chiral symmetry
Ecker, G.
1989-01-01
The ambiguities in the off-shell behaviour of spin-1 exchange can be resolved to O(p 4 ) in the chiral low-energy expansion if the asymptotic behaviour of QCD is properly incorporated. As a consequence, the chiral version of vector (and axial-vector) meson dominance is model independent. Additional high-energy constraints motivated by QCD determine the V,A resonance couplings uniquely. In particular, QCD in its effective chiral realization sucessfully predicts Γ(ρ→2π). 10 refs. (Author)
Meson theory and nuclear matter
Skyrme, T.H.R.
1994-01-01
An attempt is made to justify the use of the concept of a 'mesic fluid' in connection with the structure of nuclear matter. A transformation is made of the usual symmetric pseudo-scalar meson theory to bring into evidence certain saturation properties, which provide a natural basis for the use of a 'self-consistent' field in the discussion of nuclear structure. Fluctuations about this semi-classical saturated state will give rise to residual interparticle forces within the nucleus, and are also briefly considered in relation to electromagnetic interactions. (author). 5 refs
[Meson spectroscopy and particle astrophysics
LoSecco, J.M.
1993-07-01
Progress in the design and construction of a light meson spectroscopy experiment is reported. The experiment will run in 1993. Some non- accelerator, activities and plans for the future are also discussed. Results of a Brookhaven beam test with a subset of the final detector are described. The test has been quite promising both in the speed with which results have been obtained and in the quality of the data itself. The status of the CsI veto is reported The target region, in particular the CsI veto experiment is Notre Dame's primary hardware responsibility on this experiment
Cheng, Jin; Yu, Kuang; Libisch, Florian; Dieterich, Johannes M; Carter, Emily A
2017-03-14
Quantum mechanical embedding theories partition a complex system into multiple spatial regions that can use different electronic structure methods within each, to optimize trade-offs between accuracy and cost. The present work incorporates accurate but expensive correlated wave function (CW) methods for a subsystem containing the phenomenon or feature of greatest interest, while self-consistently capturing quantum effects of the surroundings using fast but less accurate density functional theory (DFT) approximations. We recently proposed two embedding methods [for a review, see: Acc. Chem. Res. 2014 , 47 , 2768 ]: density functional embedding theory (DFET) and potential functional embedding theory (PFET). DFET provides a fast but non-self-consistent density-based embedding scheme, whereas PFET offers a more rigorous theoretical framework to perform fully self-consistent, variational CW/DFT calculations [as defined in part 1, CW/DFT means subsystem 1(2) is treated with CW(DFT) methods]. When originally presented, PFET was only tested at the DFT/DFT level of theory as a proof of principle within a planewave (PW) basis. Part 1 of this two-part series demonstrated that PFET can be made to work well with mixed Gaussian type orbital (GTO)/PW bases, as long as optimized GTO bases and consistent electron-ion potentials are employed throughout. Here in part 2 we conduct the first PFET calculations at the CW/DFT level and compare them to DFET and full CW benchmarks. We test the performance of PFET at the CW/DFT level for a variety of types of interactions (hydrogen bonding, metallic, and ionic). By introducing an intermediate CW/DFT embedding scheme denoted DFET/PFET, we show how PFET remedies different types of errors in DFET, serving as a more robust type of embedding theory.
A Study of Neutral B Meson Time Evolution Using Exclusively Reconstructed Semileptonic Decays
Meyer, T
2003-11-05
The Standard Model of particle physics describes the fundamental building blocks of the Universe and their basic interactions. The model naturally describes the time evolution of the basic particles, of which lifetime and mixing are two examples. The neutral B meson, consisting of a bottom quark and an oppositely charged down quark, enjoys a lifetime of about 1.5 ps and the special property of mixing with its antiparticle partner, the {bar B}{sup 0}. That is, due to second order weak interactions, the B{sup 0} meson can change into a {bar B}{sup 0} meson and back again as it evolves through time. The details of this behavior offer an opportunity to closely examine the Standard Model. In this dissertation, I report on a measurement of the lifetime and mixing frequency of the neutral B meson. Using the semileptonic decay channel B{sup 0} {yields} D*{sup -}{ell}{sup +}{bar {nu}}{sub {ell}}, we select more than 68,000 signal and background candidates from about 23 million B{bar B} pairs collected in 1999-2000 with the BABAR detector located at the Stanford Linear Accelerator Center. The other B in the event is reconstructed inclusively. By constructing a master probability density function that describes the distribution of decay time differences in the sample, we use a maximum likelihood technique to simultaneously extract the B{sup 0} lifetime and mixing parameters with precision comparable to the year 2000 world average. The results are {tau}{sub B{sup 0}} = (1.523{sub -0.023}{sup +0.024} {+-} 0.022) ps and {Delta}m{sub d} = (0.492 {+-} 0.018 {+-} 0.013) ps{sup -1}. The statistical correlation coefficient between {tau}{sub B{sup 0}} and {Delta}m{sub d} is -0.22. I describe in detail several cutting-edge strategies this analysis uses to study these phenomena, laying important groundwork for the future. I also discuss several extensions of this work to include possible measurements of higher order parameters such as {Delta}{Lambda}{sub d}.
Executive Functions after Age 5: Changes and Correlates
Best, John R.; Miller, Patricia H.; Jones, Lara L.
2009-01-01
Research and theorizing on executive function (EF) in childhood has been disproportionately focused on preschool age children. This review paper outlines the importance of examining EF throughout childhood, and even across the lifespan. First, examining EF in older children can address the question of whether EF is a unitary construct. The…
Correlation between cognitive function, gross motor skills and health â
Saly Said Abd El-Hady
and health – Related quality of life in children with Down syndrome. Saly Said Abd El-Hady ... knowledge. It is a general term involving multiple classes of mental capacities. ..... organizations that can inappropriately influence this work. .... skills, cognitive development and balance functions of children with Down · syndrome.
Development and testing of new exchange correlation functionals
Lundgård, Keld Troen
, selectivity or similar of current chemical processes, or to make new technologies economical feasible. Kohn-Sham density functional theory (KS-DFT) has proven to be a powerful theory to find trends in current catalytic materials, which can empower a more informed search for better alternatives. KS-DFT relies...
Current correlation functions of ideal Fermi gas at finite temperature
in the study of time dependent density functional theory [5] due to the work of Vignale and. Kohn [6,7]. They obtained ... part has relevance to the study of viscous effects [10] in the electron gas and to the dia- magnetic ... is found that the diamagnetic susceptibility, related to the transverse part, smoothly cross over from ...
Temperature, chemical potential and the ρ meson
Roberts, C. D.; Schmidt, S. M.
2000-01-01
Models of QCD must confront nonperturbative phenomena such as confinement, dynamical chiral symmetry breaking (DCSB) and the formation of bound states. In addition, a unified approach should describe the deconfinement and chiral symmetry restoring phase transition exhibited by strongly-interacting matter under extreme conditions of temperature and density. Nonperturbative Dyson-Schwinger equation (DSE) models provide insight into a wide range of zero temperature hadronic phenomena; e.g., non-hadronic electroweak interactions of light- and heavy-mesons, and diverse meson-meson and meson-nucleon form factors. This is the foundation for their application at nonzero-(T, μ). Herein the authors describe the calculation of the reconfinement and chiral symmetry restoring phase boundary, and the medium dependence of ρ-meson properties. They also introduce an extension to describe the time-evolution in the plasma of the quark's scalar and vector self energies based on a Vlasov equation
Light Vector Mesons in the Nuclear Medium
Wood, Michael; Nasseripour, Rakhsha; Weygand, Dennis; Djalali, Chaden; Tur, Clarisse; Mosel, Ulrich; Muehlich, Pascal; Adams, Gary; Amaryan, Moscov; Amaryan, Moskov; Ambrozewicz, Pawel; Anghinolfi, Marco; Asryan, Gegham; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, James; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Bouchigny, Sylvain; Boyarinov, Sergey; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Burkert, Volker; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Carnahan, Bryan; Casey, Liam; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Crabb, Donald; Crannell, Hall; Crede, Volker; Cummings, John; Dashyan, Natalya; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Deur, Alexandre; Dharmawardane, Kahanawita; Dickson, Richard; Dodge, Gail; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fedotov, Gleb; Feldman, Gerald; Feuerbach, Robert; Fradi, Ahmed; Funsten, Herbert; Garcon, Michel; Gavalian, Gagik; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Gordon, Christopher; Gothe, Ralf; Griffioen, Keith; Guidal, Michel; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hakobyan, Hayk; Hakobyan, Rafael; Hanretty, Charles; Hardie, John; Hassall, Neil; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Kellie, James; Khandaker, Mahbubul; Khetarpal, Puneet; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klimenko, Alexei; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, David; Li, Ji; Livingston, Kenneth; Lu, Haiyun; MacCormick, Marion; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mehrabyan, Surik; Melone, Joseph; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Minehart, Ralph; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Pereira, Sergio; Pierce, Joshua; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Prok, Yelena; Protopopescu, Dan; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Ronchetti, Federico; Rosner, Guenther; Rossi, Patrizia; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schumacher, Reinhard; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shvedunov, Nikolay; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinsky, Aleksey; Stepanyan, Stepan; Stepanyan, Samuel; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Todor, Luminita; Ungaro, Maurizio; Vineyard, Michael; Vlassov, Alexander; Watts, Daniel; Weinstein, Lawrence; Williams, Michael; Wolin, Elliott; Yegneswaran, Amrit; Zana, Lorenzo; Zhang, Bin; Zhang, Jixie; Zhao, Bo; Zhao, Zhiwen
2008-07-01
The light vector mesons ($\\rho$, $\\omega$, and $\\phi$) were produced in deuterium, carbon, titanium, and iron targets in a search for possible in-medium modifications to the properties of the $\\rho$ meson at normal nuclear densities and zero temperature. The vector mesons were detected with the CEBAF Large Acceptance Spectrometer (CLAS) via their decays to $e^{+}e^{-}$. The rare leptonic decay was chosen to reduce final-state interactions. A combinatorial background was subtracted from the invariant mass spectra using a well-established event-mixing technique. The $\\rho$ meson mass spectrum was extracted after the $\\omega$ and $\\phi$ signals were removed in a nearly model-independent way. Comparisons were made between the $\\rho$ mass spectra from the heavy targets ($A > 2$) with the mass spectrum extracted from the deuterium target. With respect to the $\\rho$-meson mass, we obtain a small shift compatible with zero. Also, we measure widths consistent with standard nuclear many-body eff
Production of charmed mesons in Z decays
Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Orteu, S.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Girone, M.; Hagelberg, R.; Harvey, J.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Maggi, M.; Markou, C.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Perrodo, P.; Pusztaszeri, J.-F.; Ranjard, F.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Tomalin, I. R.; Veenhof, R.; Wachsmuth, H.; Wasserbaech, S.; Wiedemann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Bardadin-Otwinowska, M.; Barres, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Saadi, F.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Johnson, S. D.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, B.; Fouque, G.; Passalacqua, L.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Delfino, M.; Georgiopoulos, C.; Ikeda, M.; Jaffe, D. E.; Levinthal, D.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Pepe=Altarelli, M.; Salomone, S.; Colrain, P.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Thorn, S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Graefe, G.; Hanke, P.; Hepp, V.; Karger, C.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, M.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Vogl, R.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttal, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Walther, S. M.; Wanke, R.; Wolf, B.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Calvet, D.; Carr, J.; Coyle, P.; Diaconu, C.; Drinkard, J.; Etienne, F.; Nicod, D.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jakobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, G.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, H.; Stiegler, U.; Denis, R. St.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Musolino, G.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Luisiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Valassi, A.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Gao, Y.; Green, M. G.; Johnson, D. L.; March, P. V.; Medcalf, T.; Mir, Ll. M.; Quazi, I. S.; Strong, J. A.; Bertin, V.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Edwards, M.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Bobbo, B.; Pitis, L.; Ragusa, F.; Bellantoni, L.; Chen, W.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Hayes, O. J.; Nachtman, J. M.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I.; Sharma, V.; Shi, Z. H.; Turk, J. D.; Walsh, A. M.; Weber, F. V.; Wu, Sau Lan; Wu, X.; Zheng, M.; Zobernig, G.
1994-03-01
The production of charmed mesonsmathop {D^0 }limits^{( - )} , D ± , and D *± is studied in a sample of 478,000 hadronic Z decays. The production rates are measured to be 10052_2005_Article_BF01559519_TeX2GIFE1.gif begin{gathered} {Γ (Z to D^{* ± } X)}/{Γ _{had }} = 0.187 ± 0.015(exp .) ± 0.013(BR), \\ {Γ (Z to D^ ± X)}/{Γ _{had }} = 0.251 ± 0.026(exp .) ± 0.025(BR), \\ {Γ (Z to mathop {D^0 }limits^{( - )} X)}/{Γ _{had }} = 0.518 ± 0.052(exp .) ± 0.035(BR), \\ where the errors from this analysis are separated from those coming from the D branching ratios (BR). The D *± momentum distribution is extracted separately forZ to cbar c andZ to bbar b events with the help of event shape variables. It is consistent with the prediction of the JETSET Monte Carlo program after adjustment of the charm fragmentation function. Constraining the shape of theZ to bbar b contribution, the average fraction of the beam energy taken by a D * meson produced in the fragmentation of a charm quark is extracted by a parametric fit to be c =0.495±0.011±0.007. Evidence for D **0 ( D 1(2420)0 and/or D {2/*}(2460)0) production is found in theD^{* ± } π ^ mp channel, accounting for a fraction (18±5±2)% of all D *± production. The relative production of vector and pseudoscalar mesons is dicussed, together with the possible effects of D ** production. The c-quark forward-backward Z-pole asymmetry is detrmined from that of high momentum D *± to be A {/FB 0,c }=(7.7±4.4)%.
Kohn-Sham density functional theory for quantum wires in arbitrary correlation regimes
Malet, F.; Mirtschink, A.P.; Cremon, J. C.; Reimann, S. M.; Gori Giorgi, P.
2013-01-01
We use the exact strong-interaction limit of the Hohenberg-Kohn energy density functional to construct an approximation for the exchange-correlation term of the Kohn-Sham approach. The resulting exchange-correlation potential is able to capture the features of the strongly correlated regime without
Gluon field strength correlation functions within a constrained instanton model
Dorokhov, A.E.; Esaibegyan, S.V.; Maximov, A.E.; Mikhailov, S.V.
2000-01-01
We suggest a constrained instanton (CI) solution in the physical QCD vacuum which is described by large-scale vacuum field fluctuations. This solution decays exponentially at large distances. It is stable only if the interaction of the instanton with the background vacuum field is small and additional constraints are introduced. The CI solution is explicitly constructed in the ansatz form, and the two-point vacuum correlator of the gluon field strengths is calculated in the framework of the effective instanton vacuum model. At small distances the results are qualitatively similar to the single instanton case; in particular, the D 1 invariant structure is small, which is in agreement with the lattice calculations. (orig.)
Meson spectroscopy at the Serpukhov accelerator
Prokoshkin, Yu.D.
1987-01-01
At present meson spectroscopy is a dominating direction of experimental studies at the IHEP accelerator. The main attention is paid to the search and study of exotic meson states. This report presents some new results obtained recently at the IHEP accelerator. First, observation is made of a narrow 1750 MeV meson decays into ηη. Above |t| ∼ 0.2 (GeV-c) 2 (t: a square of 4-momentum transferred to a neutron), a clear narrow peak appears in Mηη mass spectrum at a mass of 1750 MeV. Second, 2.22 GeV narrow meson decaying into η'η is described. At present only premature conclusions have been obtained in this area and the situation with ζ is not clear. Third, a study is made on new exotic tensor meson χ(1810) decaying into 4π deg and ηη channels. The decay M deg → 4π deg is a very promissing instrument in search for exotic mesons. Next, G(1590)-meson as a scalar glueball is discussed. BR(G → 4π deg) has a large value, an independent evidence of the exotic nature of G(1590)-meson. Experimental data obtained on all essential decay channels of G(1590)-meson allows to give a selfconsistent description of its production and decay as the scalar glueball, a particle with the dominating gluon component. The final two parts deal with exotic vector meson C(1480) decaying into ψπ deg and observation of D(1285) → ψγ decay. (Nogami, K.)
Stoichiometric Correlation Analysis: Principles of Metabolic Functionality from Metabolomics Data
Kevin Schwahn
2017-12-01
Full Text Available Recent advances in metabolomics technologies have resulted in high-quality (time-resolved metabolic profiles with an increasing coverage of metabolic pathways. These data profiles represent read-outs from often non-linear dynamics of metabolic networks. Yet, metabolic profiles have largely been explored with regression-based approaches that only capture linear relationships, rendering it difficult to determine the extent to which the data reflect the underlying reaction rates and their couplings. Here we propose an approach termed Stoichiometric Correlation Analysis (SCA based on correlation between positive linear combinations of log-transformed metabolic profiles. The log-transformation is due to the evidence that metabolic networks can be modeled by mass action law and kinetics derived from it. Unlike the existing approaches which establish a relation between pairs of metabolites, SCA facilitates the discovery of higher-order dependence between more than two metabolites. By using a paradigmatic model of the tricarboxylic acid cycle we show that the higher-order dependence reflects the coupling of concentration of reactant complexes, capturing the subtle difference between the employed enzyme kinetics. Using time-resolved metabolic profiles from Arabidopsis thaliana and Escherichia coli, we show that SCA can be used to quantify the difference in coupling of reactant complexes, and hence, reaction rates, underlying the stringent response in these model organisms. By using SCA with data from natural variation of wild and domesticated wheat and tomato accession, we demonstrate that the domestication is accompanied by loss of such couplings, in these species. Therefore, application of SCA to metabolomics data from natural variation in wild and domesticated populations provides a mechanistic way to understanding domestication and its relation to metabolic networks.
Globally conformal invariant gauge field theory with rational correlation functions
Nikolov, N M; Todorov, I T; CERN. Geneva; Todorov, Ivan T.
2003-01-01
Operator product expansions (OPE) for the product of a scalar field with its conjugate are presented as infinite sums of bilocal fields $V_{\\kappa} (x_1, x_2)$ of dimension $(\\kappa, \\kappa)$. For a {\\it globally conformal invariant} (GCI) theory we write down the OPE of $V_{\\kappa}$ into a series of {\\it twist} (dimension minus rank) $2\\kappa$ symmetric traceless tensor fields with coefficients computed from the (rational) 4-point function of the scalar field. We argue that the theory of a GCI hermitian scalar field ${\\cal L} (x)$ of dimension 4 in $D = 4$ Minkowski space such that the 3-point functions of a pair of ${\\cal L}$'s and a scalar field of dimension 2 or 4 vanish can be interpreted as the theory of local observables of a conformally invariant fixed point in a gauge theory with Lagrangian density ${\\cal L} (x)$.
Density functional application to strongly correlated electron systems
Eschrig, H.; Koepernik, K.; Chaplygin, I.
2003-01-01
The local spin density approximation plus onsite Coulomb repulsion approach (LSDA+U) to density functional theory is carefully reanalyzed. Its possible link to single-particle Green's function theory is occasionally discussed. A simple and elegant derivation of the important sum rules for the on-site interaction matrix elements linking them to the values of U and J is presented. All necessary expressions for an implementation of LSDA+U into a non-orthogonal basis solver for the Kohn-Sham equations are given, and implementation into the full-potential local-orbital solver (Phys. Rev. B 59 (1999) 1743) is made. Results of application to several planar cuprate structures are reported in detail and conclusions on the interpretation of the physics of the electronic structure of the cuprates are drawn
The properties of tagged lattice fluids: II. Velocity correlation functions
Binder, P.M.; d'Humieres, D.; Poujol, L.
1988-01-01
We report preliminary measurements of the velocity autocorrelation function for a tagged particle in a lattice gas. These measurements agree with the Boltzmann-level theory. The Green-Kubo integration of these measurements agrees with theoretical predictions for the diffusion coefficient. To within the error bars of the simulations (3 /times/ 10/sup /minus/3/) we observe no long-time tails. 9 refs., 1 fig., 1 tab
Influence Function and Robust Variant of Kernel Canonical Correlation Analysis
Alam, Md. Ashad; Fukumizu, Kenji; Wang, Yu-Ping
2017-01-01
Many unsupervised kernel methods rely on the estimation of the kernel covariance operator (kernel CO) or kernel cross-covariance operator (kernel CCO). Both kernel CO and kernel CCO are sensitive to contaminated data, even when bounded positive definite kernels are used. To the best of our knowledge, there are few well-founded robust kernel methods for statistical unsupervised learning. In addition, while the influence function (IF) of an estimator can characterize its robustness, asymptotic ...
Nuclear physics brought about by the π-mesons studied from field theory and experiments
Toki, Hiroshi
2012-01-01
In nuclei π-mesons are playing key role. At first the important interactions of π-mesons in light nuclei is explained mentioning that the π-meson exchange force is tensor force. It is pointed out that the importance of π-meson is observed even in the deuterons. By the progress of computations it is possible at present to calculate nuclei up to the mass number of twelve. It is explained then how to handle the π-mesons in heavy nuclei referring to the discovery of the halo of 11 Li and its analysis. Due to the pseudo scalar properties of the π-mesons, tensor force is the strong nucleon-nucleon interaction. It has been necessary to go through numbers of trials and errors to arrive at the discovery of the proper tensor force analysis. It is shown to be possible to handle them in the Tensor-Optimized Shell Model (TOSM) based on the variation method. The explanation of the Extended Brueckner Hartree-Fock (EBHF) method obtained by combining the TOSM with the mean field theory used in the heavy nuclei is given. EBHF theory has the structure including high momentum components in the 2p2h wave functions. Calculated equation of state of symmetric nuclear matter is shown as a function of density in which important contribution of the tensor force is observed. Properties of nuclear matter are discussed. (S. Funahashi)
Functional neural correlates of reduced physiological falls risk
Hsu Chun
2011-08-01
Full Text Available Abstract Background It is currently unclear whether the function of brain regions associated with executive cognitive processing are independently associated with reduced physiological falls risk. If these are related, it would suggest that the development of interventions targeted at improving executive neurocognitive function would be an effective new approach for reducing physiological falls risk in seniors. Methods We performed a secondary analysis of 73 community-dwelling senior women aged 65 to 75 years old who participated in a 12-month randomized controlled trial of resistance training. Functional MRI data were acquired while participants performed a modified Eriksen Flanker Task - a task of selective attention and conflict resolution. Brain volumes were obtained using MRI. Falls risk was assessed using the Physiological Profile Assessment (PPA. Results After accounting for baseline age, experimental group, baseline PPA score, and total baseline white matter brain volume, baseline activation in the left frontal orbital cortex extending towards the insula was negatively associated with reduced physiological falls risk over the 12-month period. In contrast, baseline activation in the paracingulate gyrus extending towards the anterior cingulate gyrus was positively associated with reduced physiological falls risk. Conclusions Baseline activation levels of brain regions underlying response inhibition and selective attention were independently associated with reduced physiological falls risk. This suggests that falls prevention strategies may be facilitated by incorporating intervention components - such as aerobic exercise - that are specifically designed to induce neurocognitive plasticity. Trial Registration ClinicalTrials.gov Identifier: NCT00426881
Hormonal regulation of alveolarization: structure-function correlation
Godinez Marye H
2006-03-01
Full Text Available Abstract Background Dexamethasone (Dex limits and all-trans-retinoic acid (RA promotes alveolarization. While structural changes resulting from such hormonal exposures are known, their functional consequences are unclear. Methods Neonatal rats were treated with Dex and/or RA during the first two weeks of life or were given RA after previous exposure to Dex. Morphology was assessed by light microscopy and radial alveolar counts. Function was evaluated by plethysmography at d13, pressure volume curves at d30, and exercise swim testing and arterial blood gases at both d15 and d30. Results Dex-treated animals had simplified lung architecture without secondary septation. Animals given RA alone had smaller, more numerous alveoli. Concomitant treatment with Dex + RA prevented the Dex-induced changes in septation. While the results of exposure to Dex + RA were sustained, the effects of RA alone were reversed two weeks after treatment was stopped. At d13, Dex-treated animals had increased lung volume, respiratory rate, tidal volume, and minute ventilation. On d15, both RA- and Dex-treated animals had hypercarbia and low arterial pH. By d30, the RA-treated animals resolved this respiratory acidosis, but Dex-treated animals continued to demonstrate blood gas and lung volume abnormalities. Concomitant RA treatment improved respiratory acidosis, but failed to normalize Dex-induced changes in pulmonary function and lung volumes. No differences in exercise tolerance were noted at either d15 or d30. RA treatment after the period of alveolarization also corrected the effects of earlier Dex exposure, but the structural changes due to RA alone were again lost two weeks after treatment. Conclusion We conclude that both RA- and corticosteroid-treatments are associated with respiratory acidosis at d15. While RA alone-induced changes in structure andrespiratory function are reversed, Dex-treated animals continue to demonstrate increased respiratory rate, minute
D-meson production by muons in the COMPASS experiment at CERN
Zvyagin, Alexander
2011-01-21
One of the physics goals of the COMPASS experiment at CERN was to measure the contribution of gluons to the nucleon spin. To achieve this, it was proposed to scatter polarized 160 GeV/c muons on a polarized deuteron target and to detect D mesons in the final state. The underlying process in this D meson production is supposed to be the Photon-Gluon Fusion (PGF), where a virtual photon emitted by the muon interacts with a gluon from the target nucleon, producing a charm-anticharm quark pair. Fragmentation of a charm (anticharm) quark leads with high probability to the creation of a D{sup 0} or D{sup *} meson, which COMPASS detects via the D{sup 0}{yields}K{pi} and D{sup *}{yields}D{sup 0}{pi}{yields}K{pi}{pi} decay modes. From the longitudinal cross section spin asymmetries of the D meson production and theoretical predictions for the PGF cross section, the gluon contribution to the nucleon spin has been measured by the COMPASS experiment. The results presented in the thesis are the following. Based on data from the year 2004 a total visible cross section of 1.8{+-}0.4 nb, for the D{sup *} meson production, has been measured, with the error being dominated by systematic effects. It is validated that the D mesons are indeed produced through the PGF process, by comparison of measured D meson kinematic distributions to the ones predicted by a theory (AROMA generator). A good agreement was found for the distribution shapes, which confirms that PGF plays a major role. However, a 20% difference was found in the number of produced D{sup 0} and D{sup 0} mesons (and for the D{sup *+} and D{sup *-} mesons as well) which is significantly larger than predicted by AROMA. Kinematic distributions of D{sup 0} and D{sup *} mesons were compared with the background and also with the nearby K{sup *}{sub 2}(1430){sup 0} resonance, using all longitudinal data taken in 2002-2006. The particle-antiparticle asymmetry has been studied as a function of several kinematic variables. The 20
Microscopic universality of complex matrix model correlation functions at weak non-Hermiticity
Akemann, G.
2002-01-01
The microscopic correlation functions of non-chiral random matrix models with complex eigenvalues are analyzed for a wide class of non-Gaussian measures. In the large-N limit of weak non-Hermiticity, where N is the size of the complex matrices, we can prove that all k-point correlation functions including an arbitrary number of Dirac mass terms are universal close to the origin. To this aim we establish the universality of the asymptotics of orthogonal polynomials in the complex plane. The universality of the correlation functions then follows from that of the kernel of orthogonal polynomials and a mapping of massive to massless correlators
Correlations in Many-Body systems from two-time Greens functions
Morawetz, K.; Kohler, H.S.
2000-01-01
The Kadanoff-Baym (KB) equations are solved numerically for infinite nuclear matter. In particular we calculate correlation energies and correlation times. Approximating the Green's functions in the KB collision kernel by the free Green's functions the Levinson equation is obtained. This approximation is valid for weak interactions and/or low densities. It relates to the extended quasi-particle approximation for the spectral function. The Levinson correlation energy reduces for large times to a second order Born approximation for the energy. Comparing the Levinson, Born and KB calculations allows for an estimate of higher order spectral corrections to the correlations. (authors)
PQCD analysis of inclusive semileptonic decays of B mesons
Li, H.; Yu, H.
1996-01-01
We develop the perturbative QCD formalism for inclusive semileptonic B meson decays, which includes Sudakov suppression from the resummation of large radiative corrections near the high end of charged lepton energy. Transverse degrees of freedom of partons are introduced to facilitate the factorization of B meson decays. Ambiguities appearing in the quark-level analysis are then avoided. A universal distribution function, arising from the nonperturbative Fermi motion of the b quark, is constructed according to the heavy quark effective field theory based operator product expansion, through which the mean and the width of the distribution function are related to hadronic matrix elements of local operators. Charged lepton spectra of the B→X ul ν decay are presented. We find 50% suppression near the end point of the spectrum. The overall suppression on the total decay rate is 8% for the free quark model, and is less than 7% for the use of smooth distribution functions. With our predictions, it is then possible to extract the Cabibbo-Kobayashi-Maskawa matrix element parallel V ub parallel from experimental data. We also discuss possible implications of our analysis when confronted with the rather small observed semileptonic branching ratio in B meson decays. copyright 1996 The American Physical Society
The time-oriented boundary states and the Lorentzian-spinfoam correlation functions
Bianchi, Eugenio; Ding You
2012-01-01
A time-oriented semiclassical boundary state is introduced to calculate the correlation function in the Lorentzian Engle-Pereira-Rovelli-Livine spinfoam model. The resulting semiclassical correlation function is shown to match with the one in Regge calculus in a proper limit.
Production of $J/\\psi$ and $\\Upsilon$ mesons in $pp$ collisions at $\\sqrt{s}$ = 8 TeV
INSPIRE-00258707; Abellan Beteta, C; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Di Ruscio, F; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Elsby, D; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; 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Zhong, L; Zvyagin, A
The production of $J/\\psi$ and $\\Upsilon$ mesons in $pp$ collisions at $\\sqrt{s}$ = 8 TeV is studied with the LHCb detector. The $J/\\psi$ and $\\Upsilon$ mesons are reconstructed in the $\\mu^+ \\mu^-$ decay mode and the signal yields are determined to fit to the $\\mu^+ \\mu^-$ invariant mass distributions. The analysis is performed in the rapidity range 2.0 < $y$ < 4.5 and transverse momentum range 0 < $pT$ < 14(15) GeV/$c$ of the $J/\\psi(\\Upsilon)$ mesons. The $J/\\psi$ and $\\Upsilon$ production cross-sections and the fractions of the $J/\\psi$ mesons from $b$-hadron decays are measured as a function of the meson $pT$ and $y$.
Observation of Bell Inequality violation in B mesons
Go, A
2004-01-01
A pair of $B^0\\bar B^0$ mesons from $\\Upsilon(4S)$ decay exhibit EPR type non-local particle-antiparticle (flavor) correlation. It is possible to write down Bell Inequality (in the CHSH form: $S\\le2$) to test the non-locality assumption of EPR. Using semileptonic $B^0$ decays of $\\Upsilon(4S)$ at Belle experiment, a clear violation of Bell Inequality in particle-antiparticle correlation is observed: S=2.725+-0.167(stat)+-0.092(syst)
Discrete symmetries with neutral mesons
Bernabéu, José
2018-01-01
Symmetries, and Symmetry Breakings, in the Laws of Physics play a crucial role in Fundamental Science. Parity and Charge Conjugation Violations prompted the consideration of Chiral Fields in the construction of the Standard Model, whereas CP-Violation needed at least three families of Quarks leading to Flavour Physics. In this Lecture I discuss the Conceptual Basis and the present experimental results for a Direct Evidence of Separate Reversal-in-Time T, CP and CPT Genuine Asymmetries in Decaying Particles like Neutral Meson Transitions, using Quantum Entanglement and the Decay as a Filtering Measurement. The eight transitions associated to the Flavour-CP eigenstate decay products of entangled neutral mesons have demonstrated with impressive significance a separate evidence of TRV and CPV in Bd-physics, whereas a CPTV asymmetry shows a 2σ effect interpreted as an upper limit. Novel CPTV observables are discussed for K physics at KLOE-2, including the difference between the semileptonic asymmetries from KL and KS, the ratios of double decay rate Intensities to Flavour-CP eigenstate decay products and the ω-effect. Their observation would lead to a change of paradigm beyond Quantum Field Theory, however there is nothing in Quantum Mechanics forbidding CPTV.
Mass corrections to Green functions in instanton vacuum model
Esaibegyan, S.V.; Tamaryan, S.N.
1987-01-01
The first nonvanishing mass corrections to the effective Green functions are calculated in the model of instanton-based vacuum consisting of a superposition of instanton-antiinstanton fluctuations. The meson current correlators are calculated with account of these corrections; the mass spectrum of pseudoscalar octet as well as the value of the kaon axial constant are found. 7 refs
Jung, J.; Alvarellos, J.E.; Garcia-Gonzalez, P.; Godby, R.W.
2004-01-01
The complex nature of electron-electron correlations is made manifest in the very simple but nontrivial problem of two electrons confined within a sphere. The description of highly nonlocal correlation and self-interaction effects by widely used local and semilocal exchange-correlation energy density functionals is shown to be unsatisfactory in most cases. Even the best such functionals exhibit significant errors in the Kohn-Sham potentials and density profiles
The elimination of singularities in pair correlation functions of a multicomponent liquid system
Vasil'jev, O.M.; Chalij, O.V.
2004-01-01
In this paper we propose a method that allows to find nonsingular expressions for pair correlation functions of a multicomponent liquid system. The nature of the method deals with using integral and differential Ornstein-Zernike equations for finding asymptotic expressions for pair correlation functions and their subsequent precision. The obtained results are analyzed taking into account their possible applicability for studying the correlative behaviour of multicomponent liquid systems
Synchrotron radiation and atom pair correlation functions in electrolyte solutions
Triolo, R.; D'Aprano, A.
1978-01-01
Despite the enormous effort invested in experimental determinations of the properties of water and aqueous solutions, understanding is still rudimentary. Many of the problems are consequences of a nonrigorous definition of interparticle interactions. It is now clear that after properly ion--water interactions in terms of probability functions of position and orientation it is possible to probe these interactions at molecular levels using diffraction experiments. The role of synchrotron x-ray radiation in this context is being examined. Emphasis is given to the possibility of performing different experiments analogous to those done using the isotopic substitution method in neutron diffraction
Functional and Anatomic Correlates of Neural Aging in Birds.
Ottinger, Mary Ann
2018-01-01
Avian species show variation in longevity, habitat, physiologic characteristics, and lifetime endocrine patterns. Lifetime reproductive and metabolic function vary. Much is known about the neurobiology of the song system in many altricial birds. Little is known about aging in neural systems in birds. Captive birds often survive beyond the age they would in the wild, providing an opportunity to gain an understanding of the physiologic and neural changes. This paper reviews the available information with the goal of capturing areas of potential investigation into gaps in our understanding of neural aging as reflected in physiologic, endocrine, and cognitive aging. Copyright © 2017 Elsevier Inc. All rights reserved.
New extended interpolating operators for hadron correlation functions
Scardino, Francesco; Papinutto, Mauro [Roma ' ' Sapienza' ' Univ. (Italy). Dipt. di Fisica; INFN, Sezione di Roma (Italy); Schaefer, Stefan [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC
2016-12-22
New extended interpolating operators made of quenched three dimensional fermions are introduced in the context of lattice QCD. The mass of the 3D fermions can be tuned in a controlled way to find a better overlap of the extended operators with the states of interest. The extended operators have good renormalisation properties and are easy to control when taking the continuum limit. Moreover the short distance behaviour of the two point functions built from these operators is greatly improved. The operators have been numerically implemented and a comparison to point sources and Jacobi smeared sources has been performed on the new CLS configurations.
New extended interpolating operators for hadron correlation functions
Scardino, Francesco; Papinutto, Mauro; Schaefer, Stefan
2016-01-01
New extended interpolating operators made of quenched three dimensional fermions are introduced in the context of lattice QCD. The mass of the 3D fermions can be tuned in a controlled way to find a better overlap of the extended operators with the states of interest. The extended operators have good renormalisation properties and are easy to control when taking the continuum limit. Moreover the short distance behaviour of the two point functions built from these operators is greatly improved. The operators have been numerically implemented and a comparison to point sources and Jacobi smeared sources has been performed on the new CLS configurations.
Correlation functions in hard and (semi-)inclusive processes
Schlegel, Marc; Meissner, Stephan; Metz, Andreas
2009-01-01
Possible relations between two a priori different classes of parton distributions, the Generalized Parton Distributions (GPDs) and the Transverse Momentum Dependent parton distributions (TMDs), are discussed in this note. Although these relations were proven to hold exactly only in simple models they imply an appealingly simple and intuitive explanation for single-spin asymmetries in semi-inclusive deep-inelastic scattering. In this context we perform a first classification of common mother functions of GPDs and TMDs, so-called Generalized Transverse Momentum Dependent parton distributions (GTMDs), investigate their GPD- and TMD-limits, and gain new insight into the nature of these relations.