WorldWideScience

Sample records for anderson meson physics

  1. Nuclear structure studies using the high resolution spectrometer at the Los Alamos Clinton P. Anderson Meson Physics Facility. Progress report

    International Nuclear Information System (INIS)

    This document constitutes a progress report (1984 to 1985) and renewal proposal for the ongoing medium energy nuclear physics research program. The research efforts were carried out with the High Resolution Spectrometer (HRS) at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF) and at Brookhaven National Laboratory. The LAMPF research includes (1) p+ nucleus scattering data for a test of nonrelativistic and relativistic models of medium energy interaction; (2) data for nuclear structure information; (3) proton + nucleon data for the study of the fundamental nucleon-nucleon interaction; and (4) development of the above models. The Brookhaven work is a study of the formation and use of hypernuclei as a tool for nuclear studies. Individual reports are indexed separately

  2. Nuclear structure studies using the high resolution spectrometer at the Los Alamos Clinton P. Anderson Meson Physics Facility. Progress report

    International Nuclear Information System (INIS)

    The research is concerned with obtaining detailed microscopic nuclear structure information (both ground state and excited state) through analyses of experimental data which have been, and which will be, obtained using the High Resolution Spectrometer (HRS) at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF). Five types of experimental/theoretical studies constitute the present research program: (1) those providing nucleon-nucleon (N-N) data which describe the free N-N interaction at small momentum transfer (the starting point for analyses based on the impulse approximation), (2) those providing data which determine how the nuclear medium modifies the free amplitudes (leading to effective amplitudes for analyses based on the impulse approximation), (3) those which provide data that validate fundamental ideas implicit in the formulation of the microscopic theories, (4) those which provide data to be analyzed to provide detailed nuclear structure information, and (5) those which provide critical evaluations of the formulations of the microscopic theories themselves

  3. Nuclear structure studies using the High Resolution Spectrometer at the Los Alamos Clinton P. Anderson Meson Physics Facility. Progress report

    International Nuclear Information System (INIS)

    The research described in this document is concerned with obtaining detailed microscopic nuclear structure information (both ground state and excited state) through analysis of experimental data which have been, and which will be, obtained using the High Resolution Spectrometer (HRS) at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF). Three types of experiments and related theoretical work constitute the research programs: (1) those which provide nucleon-nucleon data to determine the key amplitudes required for microscopic analysis of intermediate energy p-nucleus elastic and inelastic scattering data, (2) those which provide data that validate fundamental ideas implicit in the formulation of the microscopic theories, and (3) those which provide data to be analyzed to provide detailed nuclear structure information

  4. Nuclear-structure studies using the high-resolution spectrometer at the Los Alamos Clinton P. Anderson Meson Physics Facility. Progress report

    International Nuclear Information System (INIS)

    This document contains a description of the ongoing medium-energy nuclear-physics research program supported by the US Department of Energy with The University of Texas at Austin. A major part of the work is associated with research done using the High Resolution Spectrometer (HRS) at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF); this research focuses on: (1) providing data which test microscopic models of the medium - energy proton + nucleus interaction; (2) providing data which are to be analyzed to provide new nuclear-structure information (both ground state and excited state); and (3) developing and improving the models themselves. Publications are listed

  5. Nuclear structure studies using the high resolution spectrometer at the Los Alamos Clinton P. Anderson Meson Physics Facility: Progress report, [1986-1987

    International Nuclear Information System (INIS)

    A major part of the work done this past year was associated with research conducted at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF) using the High Resolution Spectrometer (HRS) and the External Proton Beam (EPB). The research focussed on (1) providing p + nucleus data which test nonrelativistic and relativistic models of the medium energy proton + nucleus interaction, (2) providing (p,p) and (p,n) data which are to be analyzed to provide new nuclear structure information (both ground state and excited state), (3) providing nucleon + nucleon data to aid in the systematic study of the fundamental nucleon-nucleon interaction, (4) developing and improving the pA models themselves, and (5) initiating new experimental programs whose goals are to search for new phenomena in nuclear physics

  6. Nuclear structure studies using the high resolution spectrometer at the Los Alamos Clinton P. Anderson Meson Physics Facility: Annual progress report, [1987-1988

    International Nuclear Information System (INIS)

    This document constitutes the (1987 to 1988) progress report for the ongoing medium energy nuclear physics research program supported by the US Department of Energy with the University of Texas at Austin. A major part of the work has been and will continue to be associated with research done at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF) using the High Resolution Spectrometer (HRS), the External Proton Beam (EPB), and the new Neutron Time of Flight Facility (NTOF). Other research is done at the Fermi National Accelerator Laboratory (FNAL). The research focuses on (1) providing proton + nucleus data which test nonrelativistic and relativistic models of the medium energy proton + nucleus interaction, (2) providing (p,p) and (p,n) data which are to be analyzed to provide new nuclear structure information (both ground state and excited state), (3) providing nucleon + nucleon data to aid in the systematic study of the fundamental nucleon-nucleon interaction, (4) developing and improving the proton + nucleus theoretical models themselves, and (5) initiating new experimental programs whose goals are to search for new phenomena in nuclear physics. 182 refs., 71 figs., 5 tabs

  7. Nuclear structure studies using the high resolution spectrometer at The Los Alamos Clinton P. Anderson Meson Physics Facility. Technical progress report

    International Nuclear Information System (INIS)

    A major part of the work is associated with research done using the High Resolution Spectrometer (HRS) at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF); this research focuses on (1) providing data which test nonrelativistic and relativistic microscopic models of the medium energy proton + nucleus interaction, (2) providing data which are to be analyzed to provide new nuclear structure information (both ground state and excited state), and (3) developing and improving the models themselves. Progress is detailed on the following studies: (A) the relativistic impulse approximation; (B) Exp 425/433/479: p + nucleus elastic and inelastic scattering at 500 MeV; (C) Exp 654: measurement of spin-rotation parameter Q for 800 MeV p + nucleus elastic scattering; (D) Exp 470: reactive content of the optical potential at 800 MeV; (E) Exp 642: 800 MeV (vector p,p') inclusive cross sections and analyzing powers; (F) Exp 392: a measurement of the Wolfenstein amplitudes for p - p and p - n scattering at 800 MeV; (G) Exp 626: measurement of triple scattering parameters for 800 MeV inclusive (vector p,p') on 1H, 2H, and 12C; (H) Exp 686U: P + 208Pb elastic and inelastic scattering at 318 MeV; (I) Exp 736: P + 40,48Ca, 54Fe elastic scattering at 318 MeV; (J) Exp 563: P + P elastic scattering at 500 and 800 MeV; (K) Exp 760: P + 1H, 40Ca, and 208Pb elastic and inelastic scattering at 650 MeV; (L) BNL Exp 758: observation of hypernuclei in the 12C(π+,K+)/sub lambda/12C reaction; (M) theoretical study of kaon + nucleus elastic and inelastic scattering; and (N) theoretical determination of effective interactions. Publications are listed

  8. Physics opportunities with meson beams

    Energy Technology Data Exchange (ETDEWEB)

    Briscoe, William J.; Doering, Michael; Haberzettl, Helmut; Strakovsky, Igor I. [The George Washington University, Washington, DC (United States); Manley, D.M. [Kent State University, Kent, OH (United States); Naruki, Megumi [Kyoto University, Kyoto (Japan); Swanson, Eric S. [University of Pittsburgh, Pittsburgh, PA (United States)

    2015-10-15

    Over the past two decades, meson photo- and electroproduction data of unprecedented quality and quantity have been measured at electromagnetic facilities worldwide. By contrast, the meson-beam data for the same hadronic final states are mostly outdated and largely of poor quality, or even non-existent, and thus provide inadequate input to help interpret, analyze, and exploit the full potential of the new electromagnetic data. To reap the full benefit of the high-precision electromagnetic data, new high-statistics data from measurements with meson beams, with good angle and energy coverage for a wide range of reactions, are critically needed to advance our knowledge in baryon and meson spectroscopy and other related areas of hadron physics. To address this situation, a state-of-the-art meson-beam facility needs to be constructed. The present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility. (orig.)

  9. Physics Opportunities with Meson Beams

    CERN Document Server

    Briscoe, William J; Haberzettl, Helmut; Manley, D Mark; Naruki, Megumi; Strakovsky, Igor I; Swanson, Eric S

    2015-01-01

    Over the past two decades, meson photo- and electro-production data of unprecedented quality and quantity have been measured at electromagnetic facilities worldwide. By contrast, the meson-beam data for the same hadronic final states are mostly outdated and largely of poor quality, or even nonexistent, and thus provide inadequate input to help interpret, analyze, and exploit the full potential of the new electromagnetic data. To reap the full benefit of the high-precision electromagnetic data, new high-statistics data from measurements with meson beams, with good angle and energy coverage for a wide range of reactions, are critically needed to advance our knowledge in baryon and meson spectroscopy and other related areas of hadron physics. To address this situation, a state of-the-art meson-beam facility needs to be constructed. The present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility.

  10. Mesonic effects in nuclear physics

    International Nuclear Information System (INIS)

    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

  11. Potential for discoveries in charm meson physics

    International Nuclear Information System (INIS)

    The possibility of using charm meson physics to test the Standard Model (SM) is reviewed. In the case of D0-bar D0 mixing, the SM contributions are carefully considered and the existence of a window for the observation of new physics is discussed. Some examples of extensions of the SM giving large mixing signals are presented. Finally, some distinctive aspects of CP violation and rare decays in charm mesons are discussed. copyright 1996 American Institute of Physics

  12. Pseudoscalar meson physics with four dynamical quarks

    CERN Document Server

    Bazavov, A; Bouchard, C; DeTar, C; Du, D; El-Khadra, A X; Foley, J; Freeland, E D; Gamiz, E; Gottlieb, Steven; Heller, U M; Hetrick, J E; Kim, J; Kronfeld, A S; Laiho, J; Levkova, L; Lightman, M; Mackenzie, P B; Neil, E T; Oktay, M; Simone, J N; Sugar, R L; Toussaint, D; Van de Water, R S; Zhou, R

    2012-01-01

    We present preliminary results for light, strange and charmed pseudoscalar meson physics from simulations using four flavors of dynamical quarks with the highly improved staggered quark (HISQ) action. These simulations include lattice spacings ranging from 0.15 to 0.06 fm, and sea-quark masses both above and at their physical value. The major results are charm meson decay constants f_D, f_{D_s} and f_{D_s}/f_D and ratios of quark masses. This talk will focus on our procedures for finding the decay constants on each ensemble, the continuum extrapolation, and estimates of systematic error.

  13. Status of chiral meson physics

    Energy Technology Data Exchange (ETDEWEB)

    Bijnens, Johan [Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, SE 22362 Lund (Sweden)

    2016-01-22

    This talk includes a short introduction to Chiral Perturbation Theory in the meson sector concentrating on a number of recent developments. I discuss the latest fit of the low-energy constants. Finite volume corrections are discussed for the case with twisted boundary conditions for form-factors and first results at two-loops for three flavours for masses. The last part discusses the extension to other symmetry breaking patterns relevant for technicolour and related theories as well as the calculation of leading logarithms to high loop orders.

  14. New physics effects from meson decays

    Indian Academy of Sciences (India)

    Anirban Kundu

    2000-07-01

    In this talk, we point out some of the present and future possible signatures of physics beyond the Standard Model from -meson decays, taking -parity conserving and violating supersymmetry as illustrative examples. An expanded version is available on hep-ph archive.

  15. B meson physics and related new physics

    International Nuclear Information System (INIS)

    We have surveyed the some models focusing on the mixings, the CP violation and the rare decay in the B meson system. The ARGUS data of the Bd0-B-bard0 mixing gives us some constraints as to parameters of these models. Especially, we have investigated the composite scale in detail using the ARGUS data of the Bd0-B-bard0 mixing and obtained some interesting results. (author)

  16. Constraining New Physics with D meson decays

    International Nuclear Information System (INIS)

    Latest Lattice results on D form factors evaluation from first principles show that the Standard Model (SM) branching ratios prediction for the leptonic Ds→ℓνℓ decays and the semileptonic SM branching ratios of the D0 and D+ meson decays are in good agreement with the world average experimental measurements. It is possible to disprove New Physics hypothesis or find bounds over several models beyond the SM. Using the observed leptonic and semileptonic branching ratios for the D meson decays, we performed a combined analysis to constrain non-standard interactions which mediate the cs¯→lν¯ transition. This is done either by a model-independent way through the corresponding Wilson coefficients or in a model-dependent way by finding the respective bounds over the relevant parameters for some models beyond the Standard Model. In particular, we obtain bounds for the Two Higgs Doublet Model Type-II and Type III, the Left–Right model, the Minimal Supersymmetric Standard Model with explicit R-parity violation and Leptoquarks. Finally, we estimate the transverse polarization of the lepton in the D0 decay and we found it can be as high as PT=0.23.

  17. Strong interaction physics: from quarks to mesons, baryons and nuclei

    International Nuclear Information System (INIS)

    We summarize some of the important physics issues confronted at the NATO Advanced Research Workshop in Cracow. The topics addressed include modern challenges in understanding baryon and meson structure, hadronic interactions and hadron properties in dense matter. (author)

  18. A calculation of the physical mass of sigma meson

    Indian Academy of Sciences (India)

    J R Morones-Ibarra; Ayax Santos-Guevara

    2007-06-01

    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 0(600). This result also shows that -meson can be considered as a two-pion resonance.

  19. K meson leptonic decays progress in nuclear physics

    CERN Document Server

    Bailey, J; Jones, P B; Brink, D M; Mulvey, J H

    2013-01-01

    Progress in Nuclear Physics, Volume 12, Part 1: K Meson Leptonic Decay: The Anomalous Magnetic Moment of the Muon and Related Topics focuses on K Meson leptonic decay. The volume first discusses K Meson leptonic decay, including weak hadronic current, polarization of the muon, form of coupling, rate of partial decay, and density function of the Dalitz plot. The text then takes a look at the anomalous magnetic moment of the muon and other topics. The theory of the anomalous magnetic moment of electrons and muon and clock paradox, including muon and special relativity and lifetime of the muon in

  20. Symposium Summary and Outlook: Twenty Years of Meson Factory Physics

    OpenAIRE

    Haxton, W. C.

    1997-01-01

    The opening of the meson factories twenty years ago provided nuclear physics with new beams, higher momentum transfers, and new opportunities for precision measurements. The resulting changes in nuclear physics were substantial, altering not only the range of physics issues identified with the field but also the manner and size of the collaborations that do nuclear physics. Inspired by the talks of this symposium, I discuss some of the accomplishments as well as some of the goals not yet reac...

  1. Recent LAMPF [Los Alamos Meson Physics Facility] research using muons

    International Nuclear Information System (INIS)

    In addition to the core programs in nuclear and particle physics, diverse experiments have been carried out that address interdisciplinary and applied topics at the Los Alamos Meson Physics Facility (LAMPF). These include muon-spin-relaxation experiments to study magnetic dynamics in spin glasses and electronic structure in heavy-fermion superconductors; muon channeling experiments to provide information on pion stopping sites in crystals; tomographic density reconstruction studies using proton energy loss; and radiation-effects experiments to explore microstructure evolution and to characterize materials for fusion devices and high-intensity accelerators. Finally, the catalysis of the d-t fusion reaction using negative muons has been extensively investigated with some surprising results including a stronger than linear dependence of the mesomolecular formation rate on target density and the observation of 150 fusions per muon under certain conditions. Recent results in those programs involving pions and muons interacting with matter are discussed

  2. Progress at LAMPF. Clinton P. Anderson Meson Physics Facility, July-December 1981

    International Nuclear Information System (INIS)

    Progress at LAMPF is the semiannual progress report of the MP Division of the Los Alamos National Laboratory. The report includes brief reports on research done at LAMPF by researchers from other institutions and Los Alamos divisions

  3. Progress at LAMPF: Clinton P. Anderson Meson Physics Facility. Progress report, January-June 1981

    International Nuclear Information System (INIS)

    Progress at LAMPF is the semiannual progress report of the MP Division of the Los Alamos National Laboratory. The report includes brief reports on research done at LAMPF by researchers from other institutions and Los Alamos divisions

  4. Progress at LAMPF, Clinton P. Anderson Meson Physics Facility, January-December 1984

    International Nuclear Information System (INIS)

    Progress at LAMPF is the annual progress report of the MP Division of the Los Alamos National Laboratory. The report includes brief reports on research done at LAMPF by researchers from other institutions and Los Alamos divisions. Abstracts of separate sections of the report were prepared separately for the data base

  5. Progress at LAMPF: Clinton P. Anderson Meson Physics Facility. Progress report, January-June 1981

    Energy Technology Data Exchange (ETDEWEB)

    Allred, J.C. (ed.)

    1981-09-01

    Progress at LAMPF is the semiannual progress report of the MP Division of the Los Alamos National Laboratory. The report includes brief reports on research done at LAMPF by researchers from other institutions and Los Alamos divisions.

  6. Progress at LAMPF: Clinton P. Anderson Meson Physics Facility. Progress report, July-December 1980

    Energy Technology Data Exchange (ETDEWEB)

    Allred, J.C. (ed.)

    1981-03-01

    Progress at LAMPF is the semiannual progress report of the MP Division of the Los Alamos National Laboratory. The report also includes brief reports on research done at LAMPF by researchers from other institutions and Los Alamos divisions.

  7. Progress at LAMPF: Clinton P. Anderson Meson Physics Facility. Progress report, July-December 1980

    International Nuclear Information System (INIS)

    Progress at LAMPF is the semiannual progress report of the MP Division of the Los Alamos National Laboratory. The report also includes brief reports on research done at LAMPF by researchers from other institutions and Los Alamos divisions

  8. Seismic vulnerability study Los Alamos Meson Physics Facility (LAMPF)

    International Nuclear Information System (INIS)

    The Los Alamos Meson Physics Facility (LAMPF), located at TA-53 of Los Alamos National Laboratory (LANL), features an 800 MeV proton accelerator used for nuclear physics and materials science research. As part of the implementation of DOE Order 5480.25 and in preparation for DOE Order 5480.28, a seismic vulnerability study of the structures, systems, and components (SSCs) supporting the beam line from the accelerator building through to the ends of die various beam stops at LAMPF has been performed. The study was accomplished using the SQUG GIP methodology to assess the capability of the various SSCs to resist an evaluation basis earthquake. The evaluation basis earthquake was selected from site specific seismic hazard studies. The goals for the study were as follows: (1) identify SSCs which are vulnerable to seismic loads; and (2) ensure that those SSCs screened during die evaluation met the performance goals required for DOE Order 5480.28. The first goal was obtained by applying the SQUG GIP methodology to those SSCS represented in the experience data base. For those SSCs not represented in the data base, information was gathered and a significant amount of engineering judgment applied to determine whether to screen the SSC or to classify it as an outlier. To assure the performance goals required by DOE Order 5480.28 are met, modifications to the SQUG GIP methodology proposed by Salmon and Kennedy were used. The results of this study ire presented in this paper

  9. Chiral symmetry and scalar meson in hadron and nuclear physics

    CERN Document Server

    Kunihiro, T

    1995-01-01

    After giving a short introduction to the Nambu-Jona-Lasinio model with an anomaly term, we show the importance of the scalar-scalar correlation in the low-energy hadron dynamics, which correlation may be summarized by a scalar-isoscalar meson, the sigma meson. The discussion is based on the chiral quark model with the sigma-meson degrees of freedom. Possible experiments are proposed to produce the elusive meson in a nucleus and detect it. In relation to a precursory soft mode for the chiral transition, the reason is clarified why the dynamic properties of the superconductor may be described by the diffusive time-dependent Ginzburg-Landau (TDGL) equation. We indicate the chiral symmetry plays a significant role also in nuclei; one may say that the stability of nuclei is due to the chiral symmetry of QCD.

  10. Testing fundamental physical principles with entangled neutral K mesons

    OpenAIRE

    Di Domenico Antonio

    2014-01-01

    The neutral kaon doublet is one of the most intriguing systems in nature. En- tangled pairs of neutral K mesons produced in ϕ-meson decays offer a unique possibility to perform important tests of fundamental discrete symmetries as well as of basic principles of quantum mechanics. This paper will focus on a novel method to perform direct T and CPT symmetry tests exploiting the Einstein-Podolsky-Rosen correlations of neutral kaon pairs produced at a ϕ-factory. The statistical significance of...

  11. A historical view on implications of sigma-meson in nuclear physics

    International Nuclear Information System (INIS)

    Remarks are given as to a long-standing problem in nuclear physics, whether the sigma-meson is a real meson resonance or a substitute for the two-pion exchange effects with I=0, JP=0+ via the excitation from the octet to the decuplet baryons. Relevance of the ΛΛ 1S0 interaction to this problem is noted in connection with the binding of the double hypernuclei. (author)

  12. Theoretical interest in B-Meson physics at the B factories, Tevatron and the LHC

    International Nuclear Information System (INIS)

    We review the salient features of B-meson physics, with particular emphasis on the measurements carried out at the B-factories and Tevatron, theoretical progress in understanding these measurements in the context of the standard model, and anticipation at the LHC. Topics discussed specifically are the current status of the Cabibbo-Kobayashi-Maskawa matrix, the CP-violating phases, rare radiative and semileptonic decays, and some selected non-leptonic two-body decays of the B mesons. (orig.)

  13. Effective Lagrangian in QCD: vector mesons and skyrmions physics

    International Nuclear Information System (INIS)

    The purpose of this communication is two fold. We first show that the proper introduction of the triplet of vector mesons, ρ, solve in an unique way the confusing question of how to stabilize the baryon solitons (Skyrmions); moreover it fixes the value of the (a-dimensional) constant in the Skyrme term as e ≅ g ρππ, explaining the origin of such a term. Second we shall indicate the numerical and analytical support for the main hypothesis made: the ρ mesons are the gauge particles associated to SUV(2), the hidden symmetry of non linear σ model. An outline of the analytical framework is given, and the numerical profile of the soliton solution, F(r), is shown, comparing the results with the Skyrme solution and its static properties

  14. The Ideal Mixing Departure in Vector Meson Physics

    CERN Document Server

    Epele, L N; Grunfeld, A G

    2002-01-01

    In this work we study the departure for the ideal $\\phi-\\omega$ mixing angle in the frame of the Nambu-Jona-Lasinio model. We have shown that in that context, the flavour symmetry breaking is unable to produce the shifting in the mixing angle. We introduce a nonet symmetry breaking in the neutral vector sector to regulate the non-strange content of the $\\phi$ meson. The phenomenon is well reproduced by our proposal.

  15. Study of photon-photon physic with the magnetic detector DM2 at the Orsay linac. Research of scalar mesons

    International Nuclear Information System (INIS)

    In hadronic physic, the existence of scalar mesons, their classification in a NONET similar to that of pseudo scalar mesons and their disintegration properties raise the question of their internal structure. We have researched this meson in Photon-Photon collisions. With the aid of the magnetic detector DM2 we have chosen and analysed events characterized by two charged particles in the central detector. We have determined the radiative width of this meson. This study shows how the scalar-isoscalar resonance ε is a '' puzzle'' for the different models of hadronic spectroscopy

  16. Present and future neutrino physics research at the Los Alamos Meson Physics Facility

    International Nuclear Information System (INIS)

    The Los Alamos Meson Physics Facility is currently the site of two neutrino experiments. A measurement of elastic scattering of electron-neutrinos on electrons is providing confirmation of the destructive interference between the weak neutral and charged currents predicted in the standard electroweak theory. A search for the appearance of /bar/ν//sub e/ is being carried out at the LAMPF beam stop, as well. The status of this experiment is described. A major new initiative is being undertaken to measure neutrino-electron scattering in a large water Cerenkov detector. This meaurement will be precise enough to provide, in combination with the meaurements to be performed at the new generation of high-energy electron-positron colliers, the first experimental study of the standard electrowak theory at the level of one-loop radiative corrections. The detector will also be a vehicle for neutrino-oscillation searches, measurement of neutrinos from supernovae, and other fundamental physics. The apparatus will consist of a neutrino production target and shield surrounded by a water Cerenkov detector. The fiducial volume of water will be approximately 7000 tons, viewed by approximately 13000 20 cm diameter photomultiplier tubes. 11 refs., 6 figs

  17. CP-Violation in B Mesons and Physics Beyond the SM

    CERN Document Server

    Naboulsi, R

    2003-01-01

    In this paper, we describe the physics beyond the Standard Model with respect to CP violation and baryon asymmetry. We describe and discuss some general model-independant considerations for new effects in B mixing and decays. A review on CP violation in the $B^0$ and $K^0$ mesons systems is given, which, we hope may familiarize new Belle members in the basic ingredients of this topic.

  18. Los Alamos Meson Physics Facility high-resolution-spectrometer dipole magnets: a summary report

    International Nuclear Information System (INIS)

    This report explains the design, fabrication, measurement, optimization, and installation of two 122 metric ton electromagnets for the High Resolution Proton Spectrometer at the Los Alamos Meson Physics Facility. These two magnets are the principal components of the proton spectrometer, which has an energy resolution of less than or equal to 10-4 FWHM. Many technical problems occurred during fabrication, measurement, and optimization, and the majority have been successfully solved. We hope that this report will help others planning similar projects

  19. Proceedings of the LAMPF workshop on photon and neutral meson physics at intermediate energies

    International Nuclear Information System (INIS)

    This volume contains the Proceedings of the Workshop on ''Photon and Neutral-Meson, Physics at Intermediate Energies,'' held at Los Alamos, New Mexico, January 7 to 9, 1987. The purpose of this workshop was to bring together scientists working in the areas of electromagnetic, heavy-ion, and light hadron physics to discuss both the physics that could be addressed and potential capabilities of new, large intermediate-energy photon detectors. Based on the papers contained in these proceedings, it appears clear that there are a number of important areas that could be addressed with a much higher resolution neutral meson detector. It is also clear that the technical capability for building a neutral meson detector for energies up to 4 GeV with solid angle of approximately 10 mrs and resolution of a few hundred keV now exists. It also appears entirely reasonable to construct such a detector to be easily transportable so that it would become a national facility, available for use at a number of different laboratories. From the many interesting papers presented and from the broad representation of physicists from laboratories in Asia, Canada, Europe, Japan, and the United States, there appears to be a strong case for proceeding with the construction of such a detector

  20. Radiological engineering evaluation of the delay time line air scrubber located at the Clinton P. Anderson Meson Physics Facility (LAMPF)

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the effects of the addition of an air scrubber to an already existing delay line and whether it would scrub 11CO2. There were three main objectives of this study. The first objective was to determine the scrubbing efficiency of the scrubber. The scrubbing efficiency was then used to predict the dose rates in the scrubber area and compare those values with measurements from radiological surveys. The third objective was to determine if the shield blocks were effective in reducing the dose rates in the scrubber area. The activities were measured before and during scrubber operation and this information was used to calculate the scrubbing efficiency and the efficiency of 11CO2 removal was determined to be around 50%. Microshield was then used to predict dose rates and compared those values with measurements from radiological surveys. This was also used to determine the that the shield blocks around the scrubber were effective in reducing the dose rates from the radiation field produced by the radionuclides in the scrubber

  1. Nucleon and meson matrix elements close to the physical point

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Andreas

    2014-07-01

    The introduction to this project is given in the report for project pr85xi ''Excited state artifacts in calculations of hadron 3-point functions''. We focus here on the discussion of more results. As explained in the report for pr85xi, we have found clear evidence that present day lattice simulations are still plagued by more severe artifacts than previously assumed. Thus, we will concentrate in this report on applications for which so little is known physics-wise that even lattice results with a possible non-negligible remaining systematic error due to discretization effects are very valuable. (orig.)

  2. CP violation in charm meson decays - A signal of new physics?

    International Nuclear Information System (INIS)

    Recent measurements of the observable Delta ACP deviate significantly from the naive Standard Model expectation and might represent a sign of new physics. It is necessary to evaluate whether this deviation is actually due to new physics or whether it can be accommodated in the Standard Model. In this talk, we discuss a possible explanation of Delta ACP within the SM with the diagrammatic approach. Different D Meson decays can be related by the SU(3) flavor symmetry which can be used to express all charm decay amplitudes by a small number of parameters (topologies). We use this approach and will find that it leads us to a framework in which an unexpectedly large value for Delta ACP arises.

  3. 50 Years of Anderson Localization

    CERN Document Server

    Abrahams, Elihu

    2010-01-01

    In his groundbreaking paper Absence of diffusion in certain random lattices (1958), Philip W. Anderson originated, described and developed the physical principles underlying the phenomenon of the localization of quantum objects due to disorder. Anderson's 1977 Nobel Prize citation featured that paper, which was fundamental for many subsequent developments in condensed matter theory and technical applications. After more than a half century, the subject continues to be of fundamental importance. In particular, in the last 25 years, the phenomenon of localization has proved to be crucial for the

  4. Photoproduction opportunities at CEBAF: Meson spectroscopy and the physics of flying {phi}`s

    Energy Technology Data Exchange (ETDEWEB)

    Dzierba, A.R. [Indiana Univ., Bloomington, IN (United States)

    1994-04-01

    The availability of high-intensity photon beams with an efficient duty-factor and with energies in the range 10 to 12 GeV makes possible studies in meson spectroscopy, rare decays and possibly symmetry tests such as CP and CPT. Indeed, with a 6 GeV tagged photon beam, realizable in the near future at CEBAF, measurements of rare radiative decays of the {phi}`s will be made. At higher energies, a photon beam could be used to answer a number of questions in meson spectroscopy. An even more exciting possibility is the use of photon beams to produce an intense source of {phi}`s. The physics contemplated at e{sup +}e{sup {minus}} {phi} factories, such as CP and CPT tests, might be also studied at CEBAF with completely different and complementary systematics; e.g. having the {phi}`s decay in flight may offer distinct advantages over {phi}`s produced at rest.

  5. The London-Anderson-Englert-Brout-Higgs-Guralnik-Hagen-Kibble-Weinberg mechanism and Higgs boson reveal the unity and future excitement of physics

    CERN Document Server

    Allen, Roland E

    2013-01-01

    The particle recently discovered by the CMS and ATLAS collaborations at CERN is almost certainly a Higgs boson, fulfilling a quest that can be traced back to three seminal high energy papers of 1964, but which is intimately connected to ideas in other areas of physics that go back much further. One might oversimplify the history of the features which (i) give mass to the W and Z particles that mediate the weak nuclear interaction, (ii) effectively break gauge invariance, (iii) eliminate physically unacceptable Nambu-Goldstone bosons, and (iv) give mass to fermions (like the electron) by collectively calling them the London-Anderson-Englert-Brout-Higgs-Guralnik-Hagen-Kibble-Weinberg mechanism. More important are the implications for the future: a Higgs boson appears to point toward supersymmetry, since new physics is required to protect its mass from enormous quantum corrections, while the discovery of neutrino masses seems to point toward grand unification of the nongravitational forces.

  6. Charmed meson physics accessible to an L = 1033 cm-2 sec-1 e+e- collider operating near charm threshold

    International Nuclear Information System (INIS)

    In this report, the potential for dedicated charmed D0, D+ and Ds meson physics in a high-luminosity e+e- collider operated near charm threshold is explored. The construction of such a high-luminosity collider or Tau-Charm Factory in conjunction with a new detector whose design draws heavily on the extensive operational experience of previous detectors at SPEAR, could achieve three orders-of-magnitude improvement in sensitivity in most areas of charmed meson studies. 27 refs., 10 figs., 9 tabs

  7. MIXING AND CP VIOLATION IN D MESONS

    OpenAIRE

    Yaouanc, A. Le; Oliver, L.; Pène, O; Raynal, J. -C.

    1995-01-01

    We review mixing and CP violation in $D$ mesons, emphasizing the differences with the other pseudoscalar mesons in the Standard Model, and show that $D$ mesons can be useful to look for physics beyond the Standard Model.

  8. Measurement and modeling of external radiation during 1985 from LAMPF [Los Alamos Meson Physics Facility] emissions

    International Nuclear Information System (INIS)

    An array of three portable, pressurized ionization chambers (PICs) continued to measure external radiation levels during 1985 caused by radionuclides emitted from the Los Alamos Meson Physics Facility (LAMPF). A Gaussian-type atmospheric dispersion model, using onsite meteorological and stack release data, was tested during this study. A more complex finite model, which takes into account the contribution of radiation at a receptor from different locations of the passing plume, was also tested. Monitoring results indicate that, as in 1984, a persistent wind up the Rio Grande Valley during the evening and early morning hours is largely responsible for causing the highest external radiation levels to occur to the northeast and north-northeast of LAMPF. However, because of increased turbulent mixing during the day, external radiation levels are generally much less during the day than at night. External radiation levels during 1985 show approximately a 75% reduction over 1984 levels. This resulted from a similar percentage reduction in LAMPF emissions caused by newly implemented emission controls. Comparison of predicted and measured daily external radiation levels indicates a high degree of correlation. The model also gives accurate estimates of measured concentrations over longer time periods. Comparison of predicted and measured hourly values indicates that the model generally tends to overpredict during the day and underpredict at night. 9 refs., 14 figs., 13 tabs

  9. Roles of chiral symmetry and the sigma meson in hadron and nuclear physics

    International Nuclear Information System (INIS)

    We first review the recent accumulating evidences of the existence of a scalar-isoscalar meson with the mass 500 to 800 MeV which may be identified with the sigma meson as the quantum fluctuation of the amplitude of the chiral order parameter . We indicate that phase shift analyses which respect chiral symmetry (ChS), analyticity and crossing symmetry of the scattering amplitude show the sigma meson pole in the s-channel as well as the ρ meson pole in the t-channel in the π-π scattering in the I=J=0 channel. We emphasize that the existence of the σ resonance does not contradict with the success of the chiral perturbation theory; phenomenological difficulties with the renormalizable linear sigma model do not necessarily deny the validity of the linear representation of ChS of QCD as given by the NJL-like models which not only admit the σ resonance but also reproduce the coupling constants Li and Hi appearing the nonlinear chiral lagrangian. We give some examples of the hadronic phenomena which are naturally accounted for with the σ meson. We show that the σ meson as the amplitude fluctuation of the chiral order parameter may be more clearly identified than in free space in hot and/or dense matter, even in finite nuclei where partial restoration of ChS may be realized. (author)

  10. The CDF silicon vertex trigger for B-mesons physics study

    International Nuclear Information System (INIS)

    The CDF scientific program includes particularly the study of some key topics of the Standard Model: 1) constraint of the CKM matrix: CP violation in B sector (B0 → π+π-) and Bs mixing (Bs0 → Ds-π+, Bs0 → Ds-π+π-π+); 2) t-quark physics (t → Wb); and processes beyond the Standard Model - e.g., Higgs searching (MSSM) in the H → b bar b mode. All the above processes have the common feature - the presence of b-quarks (B-mesons). B hadrons of sufficiently high transverse momentum are characterized by a large mean value of distribution of the impact parameter with respect to the beam axis. That means events containing this kind of particles can be recognized and separated from non-long-lived background simply by cutting on the track's impact parameter. The upgraded CDF is equipped by the so-called Silicon Vertex Tracker (SVT), a unique electronic device for real time track reconstruction using the data from two CDF track detectors: the silicon strip vertex detector and drift chamber. The SVT is a level-2 trigger which within 10 μs reconstructs the tracks and obtains the transverse momentum (pt), azimuthal angle (φ) and impact parameter (d) with 30 μm precision. The simulation studies show the background reduction by factor 1000 for B0 π+π- by demand d > 100 μm for at least two tracks. This trigger is the first one of this sort ever used for hadron collider experiments: it enables to trigger on the secondary vertex, which opens the unique new opportunities in the heavy quark physics study. The basic logic, architecture and perspectives of SVT application are briefly described

  11. Light meson physics with Crystal Ball/MAMI and at BES-III

    International Nuclear Information System (INIS)

    Rare decays of light mesons like η, η', and ω offer excellent possibilities to study fundamental symmetries and symmetry-breaking patterns. Furthermore, electromagentic transitions with vertices Pγ*γ as in decays of light pseudoscalar mesons (P) or meson production in e+e- collisions give insight into hadronic structure through transition form factors and produce additional constraints for the determination of the anomalous magnetic moment of the muon (g - 2)μ. In this article, recent results on η and ω decays from the Crystal Ball at MAMI experiment as well as feasibility studies on transition form factors for the Crystal Ball and the BES-III at BEPC-II facility are presented.

  12. Interview with Philip W. Anderson

    International Nuclear Information System (INIS)

    Phil Anderson, Professor of Physics at Princeton University, has devoted his career to research in theoretical physics. He is a member of the National Academy of Science and the American Academy of Arts and Sciences, a foreign member of the Royal Society, and a foreign associate of the Accademia Lincei in Rome. The Americal Physical Society awarded him the Oliver E. Buckley Solid State Physics Prize in 1964. In 1977 he won the Nobel Prize in Physics with J.H. van Vleck and N.F. Mott. His work has encompassed a broad range of subjects: quantum theory of condensed matter, broken symmetry, transport theory and localization, random statistical systems, spectral line broadening, superfluidity in helium and neutron stars, magnetism, and superconductivity. His avocations include ''hiking, the game of GO, Romanesque architecture, and the human condition.'' In this interview he explains his RVB theory of the oxide superconductors and its historical context

  13. Extracting physics from an unphysical situation: Light mesons in a small box

    International Nuclear Information System (INIS)

    Quantum Chromo Dynamics is considered in a setup where the light mesons are squeezed into unphysically small boxes. We show how such a situation can be used to determine the couplings of the low energy chiral Lagrangian from lattice simulations, applying chirally invariant formulations of lattice fermions. (orig.)

  14. CP violation in D meson decays: would it be a sign of new physics ?

    OpenAIRE

    Buccella, Franco; Lusignoli, Maurizio; Pugliese, Alessandra; Santorelli, Pietro

    2013-01-01

    Ascribing the large SU(3) violations in the Cabibbo forbidden decays of neutral D mesons to the final state interactions, one gets large strong phase differences, necessary for substantial direct CP violation. While the absolute value of the CP violating asymmetries depend on the uncertain strength of the penguin contribution, we predict an asymmetry for the decays into charged pions more than twice as large and having opposite sign with respect to that for charged kaons.

  15. CP violation in D meson decays: Would it be a sign of new physics?

    Science.gov (United States)

    Buccella, Franco; Lusignoli, Maurizio; Pugliese, Alessandra; Santorelli, Pietro

    2013-10-01

    Ascribing the large SU(3) violations in the singly Cabibbo suppressed decays of neutral D mesons to the final state interactions, one gets large strong phase differences, necessary for substantial direct CP violation. While the absolute value of the CP violating asymmetries depend on the uncertain strength of the penguin contribution, we predict an asymmetry for the decays into charged pions more than twice as large and having opposite sign with respect to that for charged kaons.

  16. Physical model of Hadrons : Barions and mesons. Physical essence of quarks and gluons and physical interpretation of their parameters

    OpenAIRE

    Rangelov, Josiph Mladenov

    2000-01-01

    The physical model (PhsMdl) of the hadrons is offered by means of the obvious analogy with the transparent surveyed PhsMdls of the vacuum and leptons in our recent works. It is assumed that the vacuum is consistent by dynamides, streamlined in junctions of some tight crystalline lattice. Every dynamide contains a neutral pair of massless contrary point-like (PntLk) elementary electric charges (ElmElc Chrgs): electrino $(-)$ and positrino $(+)$. By means of the existent fundamental analogy bet...

  17. B meson proper time measurements with the LHCb experiment impact on physics parameters and calibration methods

    CERN Document Server

    Balbi, G

    2007-01-01

    The LHCb (Large Hadron Collider beauty) experiment is one of the four experiments at the LHC, and is specifically dedicated to explore the B-meson dynamics. To this end, LHCb will exploit the large beauty production cross section, expected to be about 500 µb at 14 TeV p-p collisions. Differently from the B-factory case, the hadronization of the b-quarks at LHC will generate all the possible B-hadrons, remarkably the Bs and Bc mesons, where the present experimental knowledge is still rather poor. The number of b/b_bar pairs produced at the LHCb interaction point will be of the order of 10^12 per year, allowing for the search of extremely rare decays, with branching fractions at the level of 10^-9. In order to reduce the acquisition rate to a sustainable level (order of 2 kHz), maintaining at the same time a high efficiency on the signals of interest, LHCb is provided with an efficient and flexible trigger system. LHCb, by means of its vertex detector, will be able to reconstruct the proper time of decays wi...

  18. Physical model of Hadrons Baryons and mesons; Physical essence of quarks and gluons and physical interpretation of their parameters

    CERN Document Server

    Rangelov, J M

    2000-01-01

    The physical model (PhsMdl) of the hadrons is offered by means of the obviousanalogy with the transparent surveyed PhsMdls of the vacuum and leptons in ourrecent works. It is assumed that the vacuum is consistent by dynamides,streamlined in junctions of some tight crystalline lattice. Every dynamidecontains a neutral pair of massless contrary point-like (PntLk) elementaryelectric charges (ElmElc Chrgs): electrino $(-)$ and positrino $(+)$. By meansof the existent fundamental analogy between their properties and behaviour wecan understand the similarity and difference between them and assume that thequark parameter aroma is determined by the value of its size of its circulartwo-dimensional motion, while the quark parameter colour is determined byorientation of the flat of the same circular two-dimensional motion in thespace. The colorless of the barions is explained by distribution of the samecircular two-dimensional motion of its elementary electric charge within threemutually perpendicular flats. Then the ex...

  19. Selected Theoretical Issues in B-meson Physics: CKM matrix and Semileptonic Decays

    CERN Document Server

    Narodetskii, I M

    2003-01-01

    These notes are a written version of a lecture given at the International Seminar {\\it Modern Trends and Classical Approach} devoted to the 80$^{th}$ anniversary of Prof. Karen Ter-Martirosyan, ITEP September 30 -- October 1, 2002. The notes represent a non-technical review of our present knowledge on the phenomenology of weak decays of quarks, and their r\\^ole in the determination of the parameters of the Standard Model. They are meant as an introduction to some of the latest results and applications in the field. Specifically, we focus on CP violation in B-decays and the determination of the CKM matrix element $V_{cb}$ from semileptonic decays of $B$ mesons. We also briefly discuss phenomenological applications concerning the electron-energy spectra in semileptonic $B$ and $B_c$ decays.

  20. Physical Origin of Density Dependent Force of the Skyrme Type within the Quark Meson Coupling Model

    Energy Technology Data Exchange (ETDEWEB)

    Pierre Guichon; Hrayr Matevosyan; N. Sandulescu; Anthony Thomas

    2006-03-17

    A density dependent, effective nucleon-nucleon force of the Skyrme type is derived from the quark-meson coupling model--a self-consistent, relativistic quark level description of nuclear matter. This new formulation requires no assumption that the mean scalar field is small and hence constitutes a significant advance over earlier work. The similarity of the effective interaction to the widely used SkM* force encourages us to apply it to a wide range of nuclear problems, beginning with the binding energies and charge distributions of doubly magic nuclei. Finding impressive results in this conventional arena, we apply the same effective interaction, within the Hartree-Fock-Bogoliubov approach, to the properties of nuclei far from stability. The resulting two neutron drip lines and shell quenching are quite satisfactory. Finally, we apply the relativistic formulation to the properties of dense nuclear matter in anticipation of future application to the properties of neutron stars.

  1. The Anderson Current Loop

    Science.gov (United States)

    Anderson, Karl F.

    1994-01-01

    Four-wire-probe concept applied to electrical-resistance transducers. Anderson current loop is excitation-and-signal-conditioning circuit suitable for use with strain gauges, resistance thermometers, and other electrical-resistance transducers mounted in harsh environments. Used as alternative to Wheatstone bridge. Simplifies signal-conditioning problem, enabling precise measurement of small changes in resistance of transducer. Eliminates some uncertainties in Wheatstone-bridge resistance-change measurements in flight research. Current loop configuration makes effects of lead-wire and contact resistances insignificantly small. Also provides output voltage that varies linearly with change in gauge resistance, and does so at double sensitivity of Wheatstone bridge.

  2. Progress at LAMPF (Los Alamos Meson Physics Facility), January--December 1989

    Energy Technology Data Exchange (ETDEWEB)

    Poelakker, K. (ed.)

    1990-12-01

    This report contains brief papers on research conducted at the lampf facility in the following areas: nuclear and particle physics; astrophysics; atomic and molecular physics; materials science; nuclear chemistry; radiation effects and radioisotope production.

  3. Progress at LAMPF [Los Alamos Meson Physics Facility], January--December 1989

    International Nuclear Information System (INIS)

    This report contains brief papers on research conducted at the lampf facility in the following areas: nuclear and particle physics; astrophysics; atomic and molecular physics; materials science; nuclear chemistry; radiation effects and radioisotope production

  4. Integrative Medicine Program- MD Anderson Cancer Center

    OpenAIRE

    Lee, Richard T.

    2012-01-01

    The Integrative Medicine Program at MD Anderson Cancer Center was first established in 1998.  Our mission is to empower patients with cancer and their families to become active partners in their own physical, psycho-spiritual, and social health through personalized education and evidenced-based clinical care to optimize health, quality of life, and clinical outcomes across the cancer continuum.  The program consists of three main components: clinical care, research, and education.  The Integr...

  5. Progress at LAMPF (Los Alamos Meson Physics Facility): Progress report, January-December 1986

    Energy Technology Data Exchange (ETDEWEB)

    Allred, J.C.; Talley, B. (eds.)

    1987-05-01

    Activities at LAMPF during the year of 1986 are summarized, including brief summaries of experiments in nuclear and particle physics, atomic and molecular physics, materials science, radiation-effects studies, biomedical research and instrumentation, nuclear chemistry, radioisotope production, and theory. The status of an advanced hadron facility currently under study is reported, as well as facility development and accelerator operations. (LEW)

  6. Progress at LAMPF [Los Alamos Meson Physics Facility]: Progress report, January-December 1986

    International Nuclear Information System (INIS)

    Activities at LAMPF during the year of 1986 are summarized, including brief summaries of experiments in nuclear and particle physics, atomic and molecular physics, materials science, radiation-effects studies, biomedical research and instrumentation, nuclear chemistry, radioisotope production, and theory. The status of an advanced hadron facility currently under study is reported, as well as facility development and accelerator operations

  7. Progress at LAMPF [Los Alamos Meson Physics Facility], January-December 1987

    International Nuclear Information System (INIS)

    This report is the annual progress report of MP Division of the Los Alamos National Laboratory. Included are brief reports on research done at LAMPF by researchers from other institutions and other Los Alamos Divisions. These reports included the following topics: Nuclear and particle physics; Atomic and molecular physics; Materials science; Radiation-effects studies; Biomedical research and instrumentation; Nuclear chemistry; Radioisotope production and accelerator facilities development and operation

  8. Measurement and modeling of gamma-absorbed doses due to atmospheric releases from Los Alamos Meson Physics Facility

    International Nuclear Information System (INIS)

    Short-term gamma-absorbed doses were measured by one high-pressure ionization chamber (HPIC) at an azimuth of 120 from the Los Alamos Meson Physics Facility (LAMPF) stack during the January 1 through February 8 operating cycle. Two HPICs were in the field during the September 8 through December 31 operating cycle, one north and the other north-northeast of the LAMPF stack, but they did not provide reliable data. Meteorological data were also measured at both East Gate and LAMPF. Airborne emission data were taken at the stack. Daily model predictions, based on the integration of modeled 15-min periods, were made for the first LAMPF operating cycle and were compared with the measured data. A comparison of the predicted and measured daily gamma doses due to LAMPF emissions is presented. There is very good correlation between measured and predicted values. During 39-day operating cycles, the model predicted an absorbed dose of 10.3 mrad compared with the 8.8 mrad that was measured, an overprediction of 17%

  9. Lithuania 1940 / Herbert Foster Anderson

    Index Scriptorium Estoniae

    Foster Anderson, Herbert

    2004-01-01

    Stseenid Leedu ennesõjaaegsest pealinnast Kaunasest briti ärimehe H. Foster Andersoni silme läbi 1940. aastal. Lühikokkuvõte raamatust: Foster Anderson, Herbert. Borderline Russia. London : Cresset press, 1942

  10. Search for new physics in rare decays of B-mesons at ATLAS

    CERN Document Server

    Price, Darren; The ATLAS collaboration

    2016-01-01

    Processes involving the FCNC transitions in b-hadron decays are suppressed in the SM and are sensitive to new physics. New results in the search for the rare decays of Bs and Bd into mu+mu- are presented. They are based on the full sample of data collected by ATLAS at 7 and 8 TeV collision energy. The consistency with the SM and with other available measurements is discussed.

  11. The Price-Anderson Act

    International Nuclear Information System (INIS)

    The Price-Anderson Act establishes nuclear liability law in the United States. First passed in 1957, it has influenced other nuclear liability legislation around the world. The insurer response the nuclear accident at Three Mile Island in 1979 demonstrates the application of the Act in a real life situation. The Price-Anderson Act is scheduled to be renewed in 2002, and the future use of commercial nuclear power in tge United States will be influenced by this renewal. (author)

  12. Semileptonic $B_{(s)}$ decays to excited charmed mesons with $e,\\mu,\\tau$ and searching for new physics with $R(D^{**})$

    CERN Document Server

    Bernlochner, Florian U

    2016-01-01

    Semileptonic $B$ meson decays into the four lightest excited charmed meson states ($D_0^*$, $D_1^*$, $D_1$, and $D_2^*$) and their counterparts with $s$ quarks are investigated, including the full lepton mass dependence. We derive the standard model predictions for the differential branching fractions, as well as predictions for the ratios of the semi-tauonic and light lepton semileptonic branching fractions. These can be systematically improved using future measurements of the total or differential semileptonic rates to $e$ and $\\mu$, as well as the two-body hadronic branching fractions with a pion, related by factorization to the semileptonic rate at maximal recoil. To illustrate the different sensitivities to new physics, we explore the dependence of the ratio of semi-tauonic and light-lepton branching fractions on the type-II two-Higgs-doublet model parameters, $\\tan\\beta$ and $m_{H}^\\pm$, for all four states.

  13. Developing an expert system to control a beam line at the Los Alamos Meson Physics Facility

    International Nuclear Information System (INIS)

    High energy particle experiments require an accelerator as a source of high energy particles. To increase the productivity of an accelerator facility, we wish to develop an expert system to control beam lines. Expert Systems are a branch of Artificial Intelligence where a computer program performs tasks requiring human expertise. Unlike most expert systems we have a physical model underlying our beam line and this model can be used with the expert system to improve performance. The development of the expert system will lead to an increased understanding of the beam line as well as the possibility of state-of-the-art expert system building

  14. Non-leptonic B meson decays as a probe of new physics

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Martin

    2009-07-17

    Despite the tremendous success of the Standard Model, the arguments for the necessity of an extension are compelling. The corresponding energy scale is expected to be O(TeV); it should lead therefore to visible effects in high-precision flavour observables. While no conclusive effect is seen there up to now, the data reveal certain puzzles when compared to Standard Model expectations based on a global fit of the CKM unitarity triangle and general theoretical expectations. The discussion of these tensions in the channels B{yields}J/{psi}K, B{yields}{phi}K, and B{yields}{pi}K, and the deduced constraints for New Physics operators of the class b{yields}s anti qq form the first project discussed in this thesis. On the other hand, hadronic uncertainties within the Standard Model are still not well understood. Therefore the opposite assumption of large hadronic Standard Model effects in B{yields}J/{psi}K is made in the second project, allowing in addition for a New Physics phase in B- anti B mixing. Finally, the necessity of reliable SM predictions is addressed by developing a framework for the model-independent inclusion of corrections to U-spin symmetry predictions. (orig.)

  15. Photon-meson transition form factors of light pseudoscalar mesons

    OpenAIRE

    Xiao, Bo-Wen; Ma, Bo-Qiang

    2005-01-01

    The photon-meson transition form factors of light pseudoscalar mesons $\\pi ^{0}$, $\\eta$, and $\\eta ^{\\prime}$ are systematically calculated in a light-cone framework, which is applicable as a light-cone quark model at low $Q^{2}$ and is also physically in accordance with the light-cone pQCD approach at large $Q^{2}$. The calculated results agree with the available experimental data at high energy scale. We also predict the low $Q^{2}$ behaviors of the photon-meson transition form factors of ...

  16. Phil Anderson's Magnetic Ideas in Science

    CERN Document Server

    Coleman, Piers

    2016-01-01

    In Philip W. Anderson's research, magnetism has always played a special role, providing a prism through which other more complex forms of collective behavior and broken symmetry could be examined. I discuss his work on magnetism from the 1950s, where his early work on antiferromagnetism led to the pseudospin treatment of superconductivity - to the 70s and 80s, highlighting his contribution to the physics of local magnetic moments. Phil's interest in the mechanism of moment formation, and screening evolved into the modern theory of the Kondo effect and heavy fermions.

  17. Pseudoscalar meson form factors and decays

    CERN Document Server

    Dorokhov, A E

    2011-01-01

    In this communication we discuss few topics related with modern experimental data on the physics of light pseudoscalar mesons. It includes the contribution of the pseudoscalar mesons to the muon anomalous magnetic moment (AMM), $g-2$, the rare decays of light pseudoscalar mesons to lepton pair, the transition form factors of pseudoscalar mesons at large momentum transfer, the pion transversity form factor. Measuring the muon anomalous magnetic moment $g-2$ and the rare decays of light pseudoscalar mesons into lepton pair $P\\rightarrow l^{+}l^{-} $ serve as important test of the standard model. To reduce the theoretical uncertainty in the standard model predictions the data on the transition form factors of light pseudoscalar mesons play significant role. Recently new data on behavior of these form factors at large momentum transfer was supplied by the BABAR collaboration. Within the nonlocal chiral quark model it shown how to describe these data and how the meson distribution amplitude evolves as a function o...

  18. State of the art in the insight into experimentally observed mesons and baryons predicted by current fundamental models of particle physics

    International Nuclear Information System (INIS)

    Current insight into mesons and baryons is highlighted, their classification is given, and their arrangement into multiplets is described. A brief chronological overview of discoveries of the most important mesons and baryons is presented, followed by a description of the attempts to find fundamental particles between mesons and baryons, which could be composed of other mesons and baryons (Fermi-Yang model, Sakata model, Ikea-Ohnuki-Ogawa model). The attempts ultimately led to the formulation of the quark model. The quark structure of some mesons and baryons is presented. The quark model foresees the existence of mesons and baryons that have not yet been discovered. (Z.J.)

  19. Note on scalar mesons

    OpenAIRE

    Törnqvist, N. A.; Spanier, S.(University of Tennessee, Knoxville, USA); Amsler, C

    2008-01-01

    This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2778 new measurements from 645 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and re...

  20. Integrative Medicine Program- MD Anderson Cancer Center

    Directory of Open Access Journals (Sweden)

    Richard T Lee

    2012-06-01

    Full Text Available The Integrative Medicine Program at MD Anderson Cancer Center was first established in 1998.  Our mission is to empower patients with cancer and their families to become active partners in their own physical, psycho-spiritual, and social health through personalized education and evidenced-based clinical care to optimize health, quality of life, and clinical outcomes across the cancer continuum.  The program consists of three main components: clinical care, research, and education.  The Integrative Medicine Center provides clinical services to patients through individual and group programs.  The clinical philosophy of the center is to work collaboratively with the oncology teams to build comprehensive and integrative care plans that are personalized, evidence-based, and safe with the goal of improving clinical outcomes.  The individual services comprise of integrative oncology consultation, acupuncture, meditation, music therapy, nutrition, and oncology massage.  The center also provides a variety of group programs including meditation, yoga, tai chi, cooking classes and others.  Over the past 13 years, over 70,000 patients and families have participated in services and programs offered by the center.  The research portfolio focuses on three main areas: mind-body interventions, acupuncture, and meditation.  This lecture will focus on providing an overview of the Integrative Medicine Program at MD Anderson with a focus on the clinical services provided.  Participants will learn about the integrative clinical model and how this is applied to the care of cancer patients at MD Anderson Cancer Center.  Current and future research topics will be discussed as well as patient cases.

  1. Light Meson Distribution Amplitudes

    CERN Document Server

    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.

  2. Anderson localization from classical trajectories

    OpenAIRE

    Brouwer, Piet W.; Altland, Alexander

    2008-01-01

    We show that Anderson localization in quasi-one dimensional conductors with ballistic electron dynamics, such as an array of ballistic chaotic cavities connected via ballistic contacts, can be understood in terms of classical electron trajectories only. At large length scales, an exponential proliferation of trajectories of nearly identical classical action generates an abundance of interference terms, which eventually leads to a suppression of transport coefficients. We quantitatively descri...

  3. Exotic meson challenges rules

    International Nuclear Information System (INIS)

    A heavy particle with an unusual decay pattern discovered by the Belle experiment at KEK in Japan is the latest addition to the meson family tree. If we had to name a modern-day Mendeleev, his name would surely be Murray Gell-Mann. In the 1960s, faced with a bewildering array of particles called hadrons that had been turning up in high-energy experiments around the world, Gell-Mann proposed that the particles were combinations of a few fundamental entities called quarks. This idea brought order into the hadronic chaos, a feat for which Gell-Man was awarded the 1969 Nobel Prize for Physics. Ever since the quark model was introduced, physicists have wanted to find out how the six different types of quarks - up (u), down (d), strange (s), charm (c), bottom (b) and top (t) - combine to form the hadrons we observe. The simple hadronic structures that we see are easy to define: mesons such as pions and kaons consist of a quark and an antiquark pair, while baryons such as protons and neutrons are made up of three quarks or three antiquarks. But the theory that describes quarks, quantum chromodynamics (QCD), also permits particles containing four or more quarks. Indeed, a meson can be more generally defined as a hadron that has an integer value of intrinsic angular momentum in quantum units, while baryons have half-integer multiples of spin. Discovering such exotic hadrons, particularly mesons with more than the minimal quark-antiquark structure, would therefore provide crucial information for our understanding of the strong force. In fact, physicists thought they had glimpsed a five-quark state called a 'pentaquark' in 2003. Sadly this excitement looks as if it was misplaced, since the latest results from dedicated experimental searches suggest that pentaquarks are a purely statistical phenomenon (see Physics World May p7: print edition only). (U.K.)

  4. Nuclear physics accelerator facilities

    International Nuclear Information System (INIS)

    This paper describes many of the nuclear physics heavy-ion accelerator facilities in the US and the research programs being conducted. The accelerators described are: Argonne National Laboratory--ATLAS; Brookhaven National Laboratory--Tandem/AGS Heavy Ion Facility; Brookhaven National Laboratory--Relativistic Heavy Ion Collider (RHIC) (Proposed); Continuous Electron Beam Accelerator Facility; Lawrence Berkeley Laboratory--Bevalac; Lawrence Berkeley Laboratory--88-Inch Cyclotron; Los Alamos National Laboratory--Clinton P. Anderson Meson Physics Facility (LAMPF); Massachusetts Institute of Technology--Bates Linear Accelerator Center; Oak Ridge National Laboratory--Holifield Heavy Ion Research Facility; Oak Ridge National Laboratory--Oak Ridge Electron Linear Accelerator; Stanford Linear Accelerator Center--Nuclear Physics Injector; Texas AandM University--Texas AandM Cyclotron; Triangle Universities Nuclear Laboratory (TUNL); University of Washington--Tandem/Superconducting Booster; and Yale University--Tandem Van de Graaff

  5. D meson decay channels that involve light scalar mesons

    Science.gov (United States)

    Fariborz, Amir

    2013-04-01

    A generalized linear sigma model of low-energy QCD is used to study several decay channels of D mesons that involve light scalar meson as a decay product. Such studies require reliable models for scalar mesons that take into account underlying mixing among quark-antiquarks, tetra quarks and glueballs. In this talk, the generalized linear sigma model of low-energy QCD for understanding the properties of scalar mosons will be briefly presented, and he application of this model to studies of heavier meson decays [such as the semileptonic decay Ds(1968)->f0(980) e^+ ν] will be presented, and a few directions for further extensions of the model will be outlined. Refs. A.H. Fariborz, R. Jora, J. Schechter and M.N. Shahid, ``Semi-leptonic Ds^+(1968) Decays as a Scalar Meson Probe,'' Physical Review D 84, 094024 (2011). A.H. Fariborz, R. Jora, J. Schechter and M.N. Shahid, ``Chiral Nonet Mixing in pi-pi Scattering,'' Physical Review D 84, 113004 (2011).

  6. Theoretical studies of multistep processes, isospin effects in nuclear scattering, and meson and baryon interactions in nuclear physics: [Annual] progress report, May 1, 1986 to April 30, 1987

    International Nuclear Information System (INIS)

    A progress report on a grant from the DOE supporting theoretical studies in nuclear physics at Oregon State University in 1986, 1987 is presented. The research was led by Professors Landau and Madsen and carried out in collaboration with graduate students in Corvallis and scientists at LLNL-Livermore, KFA-Juelich, Purdue University, Florida State University and TRIUMF. The studies included meson exchange current effects deduced from spin observables in p-3He scattering, coupled bound and continuum eigenstates in momentum space for kaons and antiprotons, and charge symmetry violation in π scattering from trinucleons. Additional studies included microscopic optical potential calculations, multiple step processes, and differences in neutron and proton multipole matrix elements and transition densities in low lying collective states and in giant resonances

  7. Interplay of Anderson localization and strong interaction in disordered systems

    International Nuclear Information System (INIS)

    We study the interplay of disorder localization and strong local interactions within the Anderson-Hubbard model. Taking into account local Mott-Hubbard physics and static screening of the disorder potential, the system is mapped onto an effective single-particle Anderson model, which is studied within the self-consistent theory of electron localization. For fermions, we find rich nonmonotonic behavior of the localization length ξ, particularly in two-dimensional systems, including an interaction-induced exponential enhancement of ξ for small and intermediate disorders and a strong reduction of ξ due to hopping suppression by strong interactions. In three dimensions, we identify for half filling a Mott-Hubbard-assisted Anderson localized phase existing between the metallic and the Mott-Hubbard-gapped phases. For small U there is re-entrant behavior from the Anderson localized phase to the metallic phase. For bosons, the unrestricted particle occupation number per lattice site yields a monotonic enhancement of ξ as a function of decreasing interaction, which we assume to persist until the superfluid Bose-Einstein condensate phase is entered. Besides, we study cold atomic gases expanding, by a diffusion process, in a weak random potential. We show that the density-density correlation function of the expanding gas is strongly affected by disorder and we estimate the typical size of a speckle spot, i.e., a region of enhanced or depleted density. Both a Fermi gas and a Bose-Einstein condensate (in a mean-field approach) are considered. (orig.)

  8. Interplay of Anderson localization and strong interaction in disordered systems

    Energy Technology Data Exchange (ETDEWEB)

    Henseler, Peter

    2010-01-15

    We study the interplay of disorder localization and strong local interactions within the Anderson-Hubbard model. Taking into account local Mott-Hubbard physics and static screening of the disorder potential, the system is mapped onto an effective single-particle Anderson model, which is studied within the self-consistent theory of electron localization. For fermions, we find rich nonmonotonic behavior of the localization length {xi}, particularly in two-dimensional systems, including an interaction-induced exponential enhancement of {xi} for small and intermediate disorders and a strong reduction of {xi} due to hopping suppression by strong interactions. In three dimensions, we identify for half filling a Mott-Hubbard-assisted Anderson localized phase existing between the metallic and the Mott-Hubbard-gapped phases. For small U there is re-entrant behavior from the Anderson localized phase to the metallic phase. For bosons, the unrestricted particle occupation number per lattice site yields a monotonic enhancement of {xi} as a function of decreasing interaction, which we assume to persist until the superfluid Bose-Einstein condensate phase is entered. Besides, we study cold atomic gases expanding, by a diffusion process, in a weak random potential. We show that the density-density correlation function of the expanding gas is strongly affected by disorder and we estimate the typical size of a speckle spot, i.e., a region of enhanced or depleted density. Both a Fermi gas and a Bose-Einstein condensate (in a mean-field approach) are considered. (orig.)

  9. η meson photoproduction on deuterium

    International Nuclear Information System (INIS)

    Measurements of the total and differential cross sections for η-meson photoproduction on a D2 liquid target from threshold to 1.2 GeV, have been taken using the tagged Bremsstrahlung photon beam produced by the electrons extracted from the ELSA storage ring at Bonn. The reaction was identified by detecting the eta decay products in the neutral meson spectrometer SPES0-2π, while the recoil baryons (proton, neutron or deuteron) were detected by a variety of large angle scintillator detectors. We succeeded to identify completely the final states corresponding to the production of an η meson on a Quasi-Free (QF) proton, a QF neutron and the coherent deuteron. The differential cross sections corresponding to the production of a coherent deuteron n the final state have been measured, from threshold to 800 MeV; they are 6 times smaller the only previous measurement reported by Anderson and Prepost in 1969. This is consistent with an Isoscalar part of the Amplitude much smaller than the Isovector one. The differential cross sections are in good agreement with the theoretical prediction on the impulse approximation mechanism; indicating in particular, fairly small contributions from rescattering terms. A direct measurement of the neutron to proton cross section ratios has been obtained by integrating the counting rates on the corresponding QF peaks and is 0.70 ± 0.03, from 700 MeV to 900 MeV, with a small angular dependence. These two results by comparison to the measured free proton data should allow to reconstruct the free neutron cross sections in a rather model-independent way. (authors). 56 refs., 90 figs., 13 tabs

  10. Photon-meson transition form factors of light pseudoscalar mesons

    CERN Document Server

    Xiao, B W; Xiao, Bo-Wen; Ma, Bo-Qiang

    2005-01-01

    The photon-meson transition form factors of light pseudoscalar mesons $\\pi ^{0}$, $\\eta $, and $\\eta ^{\\prime}$ are systematically calculated in a light-cone framework, which is applicable as a light-cone quark model at low $Q^{2}$ and is also physically in accordance with the light-cone pQCD approach at large $Q^{2}$. The calculated results agree with the available experimental data at high energy scale. We also predict the low $Q^{2}$ behaviors of the photon-meson transition form factors of $\\pi ^{0}$, $\\eta $ and $\\eta ^{\\prime }$, which are measurable in $e+A({Nucleus})\\to e+A+M$ process via Primakoff effect at JLab and DESY.

  11. Theoretical overview: The New mesons

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, Chris; /Fermilab

    2004-11-01

    After commenting on the state of contemporary hadronic physics and spectroscopy, I highlight four areas where the action is: searching for the relevant degrees of freedom, mesons with beauty and charm, chiral symmetry and the D{sub sJ} levels, and X(3872) and the lost tribes of charmonium.

  12. Meson facility. Powerful new research tool

    International Nuclear Information System (INIS)

    A meson facility is being built at the Institute of Nuclear Research, USSR Academy of Sciences, in Troitsk, where the Scientific Center, USSR Academy of Sciences is located. The facility will include a linear accelerator for protons and negative hydrogen ions with 600 MeV energy and 0.5-1 mA beam current. Some fundamental studies that can be studied at a meson facility are described in the areas of elementary particles, neutron physics, solid state physics, and applied research. The characteristics of the linear accelerator are given and the meson facility's experimental complex is described

  13. B physics: measurement of partial widths and search for direct cp violation in d0 meson decays

    Energy Technology Data Exchange (ETDEWEB)

    Acosta, D.; The CDF Collaboration

    2005-04-04

    We present a measurement of relative partial widths and decay rate CP asymmetries in K{sup -}K{sup +} and {pi}{sup -}{pi}{sup +} decays of D{sup 0} mesons produced in p{bar p} collisions at {radical}s = 1.96TeV. We use a sample of 2 x 10{sup 5} D*{sup +} {yields} D{sup 0}{pi}{sup +} (and charge conjugate) decays with the D{sup 0} decaying to K{sup -}{pi}{sup +}, K{sup -}K{sup +}, and {pi}{sup -}{pi}{sup +}, corresponding to 123 pb{sup -1} of data collected by the Collider Detector at Fermilab II experiment at the Fermilab Tevatron collider. No significant direct CP violation is observed. We measure {Lambda}(D{sup 0} {yields} K{sup -}K{sup +})/{Lambda}(D{sup 0} {yields} K{sup -}{pi}{sup +}) = 0.0992 {+-} 0.0011 {+-} 0.0012, {Lambda}(D{sup 0} {yields} {pi}{sup -}{pi}{sup +})/{Lambda}(D{sup 0} {yields} K{sup -}{pi}{sup +}) = 0.03594 {+-} 0.00054 {+-} 0.00040, A{sub CP} (K{sup -}K{sup +}) = (2.0 {+-} 1.2 {+-} 0.6)%, and A{sub CP} ({pi}{sup -}{pi}{sup +}) = (1.0 {+-} 1.3 {+-} 0.6) %, where, in all cases, the first uncertainty is statistical and the second is systematic.

  14. Benedict Andersons forestillede fællesskaber

    DEFF Research Database (Denmark)

    Ivarsson, Søren

    2007-01-01

    Artiklen diskuterer Benedict Andersons analyse af nationalismens opståen i en kolonial kontekst og den kritik som Partha Chatterjee har rejst mod denne. Udgivelsesdato: Januar 2008......Artiklen diskuterer Benedict Andersons analyse af nationalismens opståen i en kolonial kontekst og den kritik som Partha Chatterjee har rejst mod denne. Udgivelsesdato: Januar 2008...

  15. Anderson localization in nonlocal nonlinear media

    OpenAIRE

    Folli, Viola; Conti, Claudio

    2012-01-01

    The effect of focusing and defocusing nonlinearities on Anderson localization in highly nonlocal media is theoretically and numerically investigated. A perturbative approach is developed to solve the nonlocal nonlinear Schroedinger equation in the presence of a random potential, showing that nonlocality stabilizes Anderson states.

  16. Photon transport enhanced by transverse Anderson localization in disordered superlattices

    CERN Document Server

    Hsieh, Pin-Chun; McMillan, James; Tsai, Min-An; Lu, Ming; Panoiu, Nicolae; Wong, Chee Wei

    2014-01-01

    One of the daunting challenges in optical physics is to accurately control the flow of light at the subwavelength scale, by patterning the optical medium one can design anisotropic media. The light transport can also be significantly affected by Anderson localization, namely the wave localization in a disordered medium, a ubiquitous phenomenon in wave physics. Here we report the photon transport and collimation enhanced by transverse Anderson localization in chip-scale dispersion engineered anisotropic media. We demonstrate a new type of anisotropic photonic structure in which diffraction is nearly completely arrested by cascaded resonant tunneling through transverse guided resonances. By perturbing the shape of more than 4,000 scatterers in these superlattices we add structural disordered in a controlled manner and uncover the mechanism of disorder-induced transverse localization at the chip-scale. Arrested spatial divergence is captured in the power-law scaling, along with exponential asymmetric mode profil...

  17. A Selection of Three ATLAS B-Physics Results: A Search Beyond the Standard Model, A Precision Measurement, and the Discovery of a New Heavy Meson

    CERN Document Server

    Taylor, Aaron

    2015-01-01

    Three recent results from the ATLAS experiment at the LHC are presented. A new excited heavy meson state is observed through its hadronic transition to the ground state. The production cross-section of B+ mesons is measured as a function of transverse momentum pT and rapidity y. A measurement of the Bs0 --> Jpsi phi decay parameters is reported.

  18. Superconductivity in Anderson lattice model

    International Nuclear Information System (INIS)

    We study the superconducting instabilities generated by the inclusion in the Anderson lattice model of a density-density attractive potential between correlated electrons on nearest-neighbouring sites. Using a description of the normal phase based on a perturbative expansion around the atomic limit, we treat the attractive potential in the broken symmetry Hartree-Fock scheme and analyze which of the possible symmetries of the superconducting order parameter leads to the highest possible transition temperature in the case of a two-dimensional square lattice. For values of the on-site f-repulsion large compared to the hopping amplitude, a suppression of any possible superconducting phase occurs, regardless of the of the symmetry of the order parameter. (author)

  19. Gauge theories: QCD and beyond : aspects of quark physics: from the phase transition to B-meson decays

    International Nuclear Information System (INIS)

    Quantum Chromodynamics (QCD) with a relatively large number of light, resp. chiral, quark flavours is considered. A self-consistent solution of the quark, gluon and ghost propagator Dyson-Schwinger equations (DSEs) in Landau gauge exhibits a phase transition. Above the critical number of fermion flavours the non-perturbative running coupling develops a plateau over a wide momentum range, and the propagators follow a power law behaviour for these momenta. Novel order parameters for the center phase transition of QCD and related theories are derived. We prove the validity of the concept for QCD. To this end we perform a self-consistent treatment of the quark propagator DSE in Landau gauge at finite temperature. The impact of the two-loop diagrams in the Landau gauge gluon propagator DSE is investigated. We find that the squint diagram contributes sizeable in the mid-momentum regime, whereas the sunset diagram yields additional corrections only at the percent level. We present a self-consistent solution of the quark-gluon vertex function in quenched Landau gauge QCD. We find that dynamical chiral symmetry breaking leads to additional (non-perturbative) vertex structures which develop their maximal strength in the mid-momentum region. These structures trigger dynamical mass generation in the quark propagator. We are able to isolate the (few) decisive structures. Consequently, the complexity of the quark-gluon vertex tensor structure can be simplified considerably. We consider angular distributions of sequential (strange) B-meson decays using both, an effective (Hamiltonian) description as well as helictiy formalism techniques. We generalize the latter to describe the semileptonic decay B →K* (→Kπ) ℓ+ℓ-.(author)

  20. Scalar and axial-vector mesons

    CERN Document Server

    Van Beveren, E; Beveren, Eef van; Rupp, George

    2007-01-01

    Nowadays, there exists an abundance of theoretical approaches towards the mesonic spectrum, ranging from confinement models of all kinds, i.e., glueballs, and quark-antiquark, multiquark and hybrid configurations, to models in which only mesonic degrees of freedom are taken into account. Nature seems to come out somewhere in the middle, neither preferring pure bound states, nor effective meson-meson physics with only coupling constants and possibly form factors. As a matter of fact, apart from a few exceptions, like pions and kaons, Nature does not allow us to study mesonic bound states of any kind, which is equivalent to saying that such states do not really exist. Hence, instead of extrapolating from pions and kaons to the remainder of the meson family, it is more democratic to consider pions and kaons mesonic resonances that happen to come out below the lowest threshold for strong decay. Nevertheless, confinement is an important ingredient for understanding the many regularities observed in mesonic spectra...

  1. Atoms and mesons. Atomy i mezony

    Energy Technology Data Exchange (ETDEWEB)

    Kirillov-Ygryumov, V.G.; Nikitin, Yu.P.; Sergeev, F.M.

    1980-01-01

    A study is made of interactions between muons and hadrons and matter. Investigations are made of hadron-nuclear and lepton-nuclear interactions in the energy range that is characteristic of meson factories (up to 200 MeV). Considerable attention is given to meson and nuclear interactions in the bound state as well as to nuclear capture of mesons. An examination is made of the formation of high-energy and ..mu..-nucleon atoms, elastic and inelastic meson scattering on nuclei, the connection between scattering processes and mesoatoms, and their role in the structural analysis of nuclei and elementary particles. A phase analysis is made of experimental results for elastic scattering on nucleons and nuclei. The book is intended for scientists specializing in the physics of low energies. It might also be used by graduate and senior undergraduate students majoring in physics and physical engineering. 103 references, 31 figures, 18 tables.

  2. Price-Anderson Law - reports on Price-Anderson issues

    International Nuclear Information System (INIS)

    Five of the six papers in this study are by experts outside the nuclear industry, and deal with fear, risk, and risk management as they apply to the review of the Price-Anderson Act. The purpose of the Act is to encourage private enterprise to develop a reliable source of electric power and to protect the public from the financial consequences of injury or damage that may occur during the process. The titles of the five papers are: (1) the effects of ionizing radiation on human health, (2) proof of causation through expert opinion evidence in low-level radiation cases, (3) a critical review of the probability of causation method, (4) the nuclear liability claims experience of the nuclear insurance pools, (5) review of nuclear liability compensation systems applicable to reactors outside the United States, and (6) the economic foundations of limited liability for nuclear reactor accidents. A separate abstract was prepared for each of the papers for EDB, EPA, and INS

  3. Light focusing in the Anderson Regime

    CERN Document Server

    Leonetti, Marco; Mafi, Arash; Conti, Claudio

    2014-01-01

    Anderson localization is a regime in which diffusion is inhibited and waves (also electromagnetic waves) get localized. Here we exploit adaptive optics to achieve focusing in disordered optical fibers in the Anderson regime. By wavefront shaping and optimization, we observe the generation of a propagation invariant beam, where light is trapped transversally by disorder, and show that Anderson localizations can be also excited by extended speckled beams. We demonstrate that disordered fibers allow a more efficient focusing action with respect to standard fibers in a way independent of their length, because of the propagation invariant features and cooperative action of transverse localizations.

  4. The η' meson from lattice QCD

    International Nuclear Information System (INIS)

    We study the flavour singlet pseudoscalar mesons from first principles using lattice QCD. With Nf=2 flavours of light quark, this is the so-called η2 meson and we discuss the phenomenological status of this. Using maximally twisted-mass lattice QCD, we extract the mass of the η2 meson at two values of the lattice spacing for lighter quarks than previously discussed in the literature. We are able to estimate the mass value in the limit of light quarks with their physical masses. (orig.)

  5. Recent progress on light scalar mesons

    OpenAIRE

    Peláez Sagredo, José Ramón

    2014-01-01

    This is a brief account of the recent developments on the determination of the mass and widths of the much debated scalar mesons, paying particular attention to the causes of major revision of the σ or f_0(500) meson in the last edition of the Review of Particle Physics, which has finally acknowledged that the situation concerning the mass and width of this controversial state has been settled, although this was already well-known to scalar meson practitioners for about a decade. I will brief...

  6. Meson radiobiology and therapy

    International Nuclear Information System (INIS)

    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.)

  7. The comparative uptake and interaction of several radionuclides in the trophic levels surrounding the Los Alamos Meson Physics Facility (LAMPF) waste water ponds

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, G.H. Jr.

    1989-08-01

    A study was undertaken to examine the uptake, distribution, and interaction of five activation products (Co-57, Be-7, Cs-134, Rb-83, and Mn-54) within the biotic and abiotic components surrounding the waste treatment lagoons of the Los Alamos Meson Physics Facility (LAMPF). The study attempted to ascertain where, and what specific interactions were taking place among the isotopes and the biotic/abiotic components. A statistical approach, utilizing Multivariate Analysis of Variance (MANOVA), was conducted testing the radioisotopic concentrations by (1) the trophic levels (TROPLVL) in each position sampled on the grid, (2) where sampled on the grid (TRAN), (3) where sampled with-in each grid line (PLOT), and (4) the side with which sampled (SIDE). This provided both the dependent and independent variables that would be tested. The Null Hypothesis (Ho) tested the difference in the mean values of the isotopes within/between each of the four independent variables. The Rb-83 statistic indicated an accumulation within the TRAN and PLOT variables within the sampled area. The Co-57 test statistic provided a value which indicated that accumulation of this isotope within TROPLVL was taking place. Mn-54 test values indicated that accumulation was also taking place at the higher trophic levels within the PLOT, TRAN, and SIDE positions. Cs-134 was found to accumulate to third level in this trophic level structure (TROPLVL-(vegetation)), and then decrease from there. The Be-7 component provided no variance from known compartmental transfers. 210 refs., 17 figs., 4 tabs.

  8. The comparative uptake and interaction of several radionuclides in the trophic levels surrounding the Los Alamos Meson Physics Facility (LAMPF) waste water ponds

    International Nuclear Information System (INIS)

    A study was undertaken to examine the uptake, distribution, and interaction of five activation products (Co-57, Be-7, Cs-134, Rb-83, and Mn-54) within the biotic and abiotic components surrounding the waste treatment lagoons of the Los Alamos Meson Physics Facility (LAMPF). The study attempted to ascertain where, and what specific interactions were taking place among the isotopes and the biotic/abiotic components. A statistical approach, utilizing Multivariate Analysis of Variance (MANOVA), was conducted testing the radioisotopic concentrations by (1) the trophic levels (TROPLVL) in each position sampled on the grid, (2) where sampled on the grid (TRAN), (3) where sampled with-in each grid line (PLOT), and (4) the side with which sampled (SIDE). This provided both the dependent and independent variables that would be tested. The Null Hypothesis (Ho) tested the difference in the mean values of the isotopes within/between each of the four independent variables. The Rb-83 statistic indicated an accumulation within the TRAN and PLOT variables within the sampled area. The Co-57 test statistic provided a value which indicated that accumulation of this isotope within TROPLVL was taking place. Mn-54 test values indicated that accumulation was also taking place at the higher trophic levels within the PLOT, TRAN, and SIDE positions. Cs-134 was found to accumulate to third level in this trophic level structure [TROPLVL-(vegetation)], and then decrease from there. The Be-7 component provided no variance from known compartmental transfers. 210 refs., 17 figs., 4 tabs

  9. Student trainee report of Walter L. Anderson

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The following report is intended to summarize the activities of Walter L. Anderson, Student Trainee (Wildlife Biology) at Malheur National Wildlife Refuge during...

  10. Anderson localization in metallic nanoparticle arrays

    Science.gov (United States)

    Mai, Zhijie; Lin, Fang; Pang, Wei; Xu, Haitao; Tan, Suiyan; Fu, Shenhe; Li, Yongyao

    2016-06-01

    Anderson localization has been observed in various types of waves, such as matter waves, optical waves and acoustic waves. Here we reveal that the effect of Anderson localization can be also induced in metallic nonlinear nanoparticle arrays excited by a random electrically driving field. We find that the dipole-induced nonlinearity results in ballistic expansion of dipole intensity during evolution; while the randomness of the external driving field can suppress such an expansion. Increasing the strength of randomness above the threshold value, a localized pattern of dipole intensity can be generated in the metallic nanoparticle arrays. By means of statistics, the mean intensity distribution of the dipoles reveals the formation of Anderson localization. We further show that the generated Anderson localization is highly confined, with its size down to the scale of incident wavelength. The reported results might facilitate the manipulations of electromagnetic fields in the scale of wavelength.

  11. Anderson localization in metallic nanoparticle arrays

    CERN Document Server

    Mai, Zhijie; Pang, Wei; Xu, Haitao; Tan, Suiyan; Fu, Shenhe; Li, Yongyao

    2016-01-01

    Anderson localization has been observed in various types of waves, such as matter waves, optical waves and acoustic waves. Here we reveal that the effect of Anderson localization can be also induced in metallic nonlinear nanoparticle arrays excited by a random electrically driving field. We find that the dipole-induced nonlinearity results in ballistic expansion of dipole intensity during evolution; while the randomness of the external driving field can suppress such an expansion. Increasing the strength of randomness above the threshold value, a localized pattern of dipole intensity can be generated in the metallic nanoparticle arrays. By means of statistics, the mean intensity distribution of the dipoles reveals the formation of Anderson localization. We further show that the generated Anderson localization is highly confined, with its size down to the scale of incident wavelength. The reported results might facilitate the manipulations of electromagnetic fields in the scale of wavelength.

  12. THE ETA-MESON PHOTOPRODUCTION ON PROTON

    Czech Academy of Sciences Publication Activity Database

    Donoval, Jan; Bydžovský, Petr

    2011-01-01

    Roč. 26, 3-4 (2011), s. 645-646. ISSN 0217-751X. [11th International Workshop on Meson Production, Properties and Interaction. Krakow, 10.06.2010-15.06.2010] R&D Projects: GA ČR GA202/08/0984 Institutional research plan: CEZ:AV0Z10480505 Keywords : Eta-meson photoproduction * form factors * nucleon resonances Subject RIV: BG - Nuclear, Atomic and Molecular Physics , Colliders Impact factor: 1.053, year: 2011

  13. B-meson decay constants from improved lattice nonrelativistic QCD with physical u, d, s, and c quarks.

    Science.gov (United States)

    Dowdall, R J; Davies, C T H; Horgan, R R; Monahan, C J; Shigemitsu, J

    2013-05-31

    We present the first lattice QCD calculation of the decay constants f(B) and f(B(s)) with physical light quark masses. We use configurations generated by the MILC Collaboration including the effect of u, d, s, and c highly improved staggered quarks in the sea at three lattice spacings and with three u/d quark mass values going down to the physical value. We use improved nonrelativistic QCD (NRQCD) for the valence b quarks. Our results are f(B)=0.186(4) GeV, f(B(s))=0.224(4) GeV, f(B(s))/f(B)=1.205(7), and M(B(s))-M(B)=85(2) MeV, superseding earlier results with NRQCD b quarks. We discuss the implications of our results for the standard model rates for B((s))→μ(+)μ(-) and B→τν. PMID:23767714

  14. Rare B Meson Decays With Omega Mesons

    Energy Technology Data Exchange (ETDEWEB)

    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}.

  15. Meson-meson processes in strong interactions

    International Nuclear Information System (INIS)

    Based on the meson-exchange framework the present work investigates the role played by meson-meson processes in strong interaction dynamics. We concentrate on two particular topics, one representing the more fundamental aspects of meson-meson systems the other being an example for the many possible applications. Using realistic meson-exchange models for ππ- and πη-scattering the first part of this work investigates the structure of the scalar meson f0(980) and a0(980) both being of outstanding importance for our understanding of the scalar meson sector. Our model produces good agreement with the available data. Furthermore, an analysis of the pole structure of the underlying ππ- and πη-scattering amplitudes leads to an understanding of the nature and parameters of f0(980) and a0(980). It is shown that besides the observed relationship between f0(980) and a0(980) their underlying structure is quite different. The second part of our investigation deals with the role played by correlated πρ exchange in the NN interaction. Starting point are open questions concerning the structure of the πNN vertex function. In the Bonn potential of the NN interaction a rather ''hard'' πNN formfactor is required in order to be able to reproduce experimental data, in particular the deuteron properties. However, this result is in disagreement with predictions from several theoretical models requiring a much softer πNN formfactor. We are able to show that this discrepancy is removed if correlated πρ exchange is added to the Bonn potential. (orig.)

  16. Quantum field theory approaches to meson structure

    International Nuclear Information System (INIS)

    Meson spectroscopy became one of the most interesting topics in particle physics in the last ten years. In particular, the discovery of new unexpected states in the charmonium spectrum which cannot be simply explained by the constituent quark model attracted the interest of many theoretical efforts. In the present thesis we discuss different meson structures ranging from light and heavy quark-antiquark states to bound states of hadrons-hadronic molecules. Here we consider the light scalar mesons f0(980) and a0(980) and the charmonium-like Y(3940), Y(4140) and Z±(4430) states. In the discussion of the meson properties like mass spectrum, total and partial decay widths and production rates we introduce three different theoretical methods for the treatment and description of hadronic structure. For the study of bound states of mesons we apply a coupled channel approach which allows for the dynamical generation of meson-meson resonances. The decay properties of meson molecules are further on studied within a second model based on effective Lagrangians describing the interaction of the bound state and its constituents. Besides hadronic molecules the effective Lagrangian approach is also used to study the radiative and strong decay properties of ordinary quark-antiquark (q anti q) states. The AdS/QCD model forms the completion of the three theoretical methods introduced in the present thesis. This holographic model provides a completely different ansatz and is based on extra dimensions and string theory. Within this framework we calculate the mass spectrum of light and heavy mesons and their decay constants.

  17. Charmed and light pseudoscalar meson decay constants from four-flavor lattice QCD with physical light quarks

    CERN Document Server

    Bazavov, A; Bouchard, C M; DeTar, C; Du, D; El-Khadra, A X; Foley, J; Freeland, E D; Gámiz, E; Gottlieb, Steven; Heller, U M; Kim, J; Komijani, J; Kronfeld, A S; Laiho, J; Levkova, L; Mackenzie, P B; Neil, E T; Simone, J N; Sugar, R; Toussaint, D; Van de Water, R S; Zhou, R

    2014-01-01

    We compute the leptonic decay constants $f_{D^+}$, $f_{D_s}$, and $f_{K^+}$, and the quark-mass ratios $m_c/m_s$ and $m_s/m_l$ in unquenched lattice QCD using the experimentally determined value of $f_{\\pi^+}$ for normalization. We use the MILC Highly Improved Staggered Quark (HISQ) ensembles with four dynamical quark flavors --- up, down, strange, and charm --- and with both physical and unphysical values of the light sea-quark masses. The use of physical pions removes the need for a chiral extrapolation, thereby eliminating a significant source of uncertainty in previous calculations. Four different lattice spacings ranging from $a\\approx 0.06$ fm to $0.15$ fm are included in the analysis to control the extrapolation to the continuum limit. Our primary results are $f_{D^+} = 212.6(0.4)({}^{+1.0}_{-1.2})\\ \\mathrm{MeV}$, $f_{D_s} = 249.0(0.3)({}^{+1.1}_{-1.5})\\ \\mathrm{MeV}$, and $f_{D_s}/f_{D^+} = 1.1712(10)({}^{+29}_{-32})$, where the errors are statistical and total systematic, respectively. The errors on ...

  18. A proposal to extend the intensity frontier of nuclear and particle physics to 45 GeV (LAMPF 2)

    International Nuclear Information System (INIS)

    It is proposed to construct and operate a high-intensity, medium energy synchrotron addition to the Clinton P. Anderson Meson Physics Facility. The addition is to consist of a 6-GeV, 170-μA booster and a 45-GeV, 34-μA, 3-Hz main synchrotron with 50% duty factor. The physics of strong and electroweak interactions to be studied at the facility is discussed, as well as accelerator design, scope of experimental area facilities, and cost estimates and schedule

  19. My Random Walks in Anderson's Garden

    CERN Document Server

    Baskaran, G

    2016-01-01

    Anderson's Garden is a drawing presented to Philip W. Anderson on the eve of his 60th birthday celebration, in 1983. This cartoon (Fig. 1), whose author is unknown, succinctly depicts some of Anderson's pre-1983 works, as a blooming garden. As an avid reader of Anderson's papers, random walk in Anderson's garden had become a part of my routine since graduate school days. This was of immense help and prepared me for a wonderful collaboration with the gardener himself, on the resonating valence bond (RVB) theory of High Tc cuprates and quantum spin liquids, at Princeton. The result was bountiful - the first (RVB mean field) theory for i) quantum spin liquids, ii) emergent fermi surfaces in Mott insulators and iii) superconductivity in doped Mott insulators. Beyond mean field theory - i) emergent gauge fields, ii) Ginzbuerg Landau theory with RVB gauge fields, iii) prediction of superconducting dome, iv) an early identification and study of a non-fermi liquid normal state of cuprates and so on. Here I narrate th...

  20. Scalar mesons in a linear sigma model with (axial-)vector mesons

    CERN Document Server

    Parganlija, D; Wolf, Gy; Giacosa, F; Rischke, D H

    2012-01-01

    The structure of the scalar mesons has been a subject of debate for many decades. In this work we look for $\\bar{q}q$ states among the physical resonances using an extended Linear Sigma Model that contains scalar, pseudoscalar, vector, and axial-vector mesons both in the non-strange and strange sectors. We perform global fits of meson masses, decay widths and amplitudes in order to ascertain whether the scalar $\\bar{q}q$ states are below or above 1 GeV. We find the scalar states above 1 GeV to be preferred as $\\bar{q}q$ states.

  1. Mesons on a transverse lattice

    CERN Document Server

    Dalley, S

    2001-01-01

    The meson eigenstates of the light-cone Hamiltonian in a coarse transverse lattice gauge theory are investigated. Building upon previous work in pure gauge theory, the Hamiltonian and its Fock space are expanded in powers of dynamical fields. In the leading approximation, the couplings appearing in the Hamiltonian are renormalised by demanding restoration of space-time symmetries broken by the cut-off. Additional requirements from chiral symmetry are discussed and difficulties in imposing them from first principles in the leading approximation are noted. A phenomenological calculation is then performed, in which chiral symmetry in spontaneously broken form is modelled by imposing the physical pion-rho mass splitting as a constraint. The light-cone wavefunctions of the resulting Hamiltonian are used to compute decay constants, form factors and quark momentum and spin distributions for the pion and rho mesons. Extensions beyond leading order, and the implications for first principles calculations, are briefly d...

  2. Measurement of Charm Meson Lifetimes

    International Nuclear Information System (INIS)

    We report measurements of the D0 , 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 D0 , 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 D0 lifetimes is 1.19±0.04 . copyright 1999 The American Physical Society

  3. Charmed and light pseudoscalar meson decay constants from four-flavor lattice QCD with physical light quarks

    Energy Technology Data Exchange (ETDEWEB)

    Bazavov, A.; Bernard, C.; Komijani, J.; Bouchard, C. M.; DeTar, C.; Foley, J.; Levkova, L.; Du, D.; Laiho, J.; El-Khadra, A. X.; Freeland, E. D.; Gámiz, E.; Gottlieb, Steven; Heller, U. M.; Kim, J.; Toussaint, D.; Kronfeld, A. S.; Mackenzie, P. B.; Simone, J. N.; Van de Water, R. S.; Zhou, R.; Neil, E. T.; Sugar, R.

    2014-10-30

    We compute the leptonic decay constants fD+, fDs, and fK+ and the quark-mass ratios mc/ms and ms/ml in unquenched lattice QCD using the experimentally determined value of fπ+ for normalization. We use the MILC highly improved staggered quark ensembles with four dynamical quark flavors—up, down, strange, and charm—and with both physical and unphysical values of the light sea-quark masses. The use of physical pions removes the need for a chiral extrapolation, thereby eliminating a significant source of uncertainty in previous calculations. Four different lattice spacings ranging from a0.06 to 0.15 fm are included in the analysis to control the extrapolation to the

  4. Signatures of Anderson localization excited by an optical frequency comb

    KAUST Repository

    Gentilini, S.

    2010-01-25

    We investigate Anderson localization of light as occurring in ultrashort excitations. A theory based on time dependent coupled-mode equations predicts universal features in the spectrum of the transmitted pulse. In particular, the process of strong localization of light is shown to correspond to the formation of peaks in both the amplitude and in the group delay of the transmitted pulse. Parallel ab initio simulations made with finite-difference time-domain codes and molecular dynamics confirm theoretical predictions, while showing that there exists an optimal degree of disorder for the strong localization. © 2010 The American Physical Society.

  5. Heavy mesons in a hadronic medium: interaction and transport coefficients

    CERN Document Server

    Torres-Rincon, Juan M; Cabrera, Daniel; Romanets, Olena; Tolos, Laura

    2015-01-01

    We review the recent results of heavy meson diffusion in thermal hadronic matter. The interactions of D and B-bar mesons with other hadrons (light mesons and baryons) are extracted from effective field theories based on chiral and heavy-quark symmetries. When these guiding principles are combined with exact unitarity, physical values of the cross sections are obtained. These cross sections (which contain resonant contributions) are used to calculate the drag and diffusion coefficients of heavy mesons immersed in a thermal and dense medium. The transport coefficients are computed using a Fokker-Planck reduction of the Boltzmann equation.

  6. Spectroscopy of exotic mesons

    International Nuclear Information System (INIS)

    The authors discuss why QCD leads to the search for exotic hadrons. They summarize some expectations from theory and models concerning the masses, decay pattern and characteristic features of glueballs (gg), hybrid (q bar qg) and diquonia (qq bar q bar q) mesons. They discuss the best known or more interesting candidates for exotic mesons

  7. Random nanolasing in the Anderson localized regime

    DEFF Research Database (Denmark)

    Liu, Jin; Garcia, P. D.; Ek, Sara;

    2014-01-01

    multiple scattering. The applicability of random lasers has been limited due to multidirectional emission, lack of tunability, and strong mode competition with chaotic fluctuations due to a weak mode confinement. The regime of Anderson localization of light has been proposed for obtaining stable multimode...... random lasing, and initial work concerned macroscopic one-dimensional layered media. Here, we demonstrate on-chip random nanolasers where the cavity feedback is provided by the intrinsic disorder. The strong confinement achieved by Anderson localization reduces the spatial overlap between lasing modes...

  8. Vector-meson dominance revisited

    Directory of Open Access Journals (Sweden)

    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.

  9. Topology dependent quantities at the Anderson transition

    OpenAIRE

    Slevin, Keith; Ohtsuki, Tomi; Kawarabayashi, Tohru

    2000-01-01

    The boundary condition dependence of the critical behavior for the three dimensional Anderson transition is investigated. A strong dependence of the scaling function and the critical conductance distribution on the boundary conditions is found, while the critical disorder and critical exponent are found to be independent of the boundary conditions.

  10. Corrections to scaling at the Anderson transition

    OpenAIRE

    Slevin, Keith; Ohtsuki, Tomi

    1998-01-01

    We report a numerical analysis of corrections to finite size scaling at the Anderson transition due to irrelevant scaling variables and non-linearities of the scaling variables. By taking proper account of these corrections, the universality of the critical exponent for the orthogonal universality class for three different distributions of the random potential is convincingly demonstrated.

  11. Effect of coulomb interaction on Anderson localization

    International Nuclear Information System (INIS)

    We study the quantum mechanics of interacting particles in a disordered system, and in particular, what happens to Anderson localisation when interaction is taken into account. In the first part, one looks at the excited states of two particles in one dimension. For this model, it has been shown (Shepelyansky 1994) that a local repulsive interaction can partially destroy Anderson localisation. Here, we show that this model has similarities with the three-dimensional Anderson model at the metal-insulator transition. In particular, the maximum of rigidity obtained in the spectral statistics correspond to some intermediary statistics that cannot be described by random matrix theory neither by a Poisson statistics. The wave functions show a multifractal behaviour and the spreading of the center of mass of a wave packet is logarithmic in time. The second part deals with the ground state of a finite density of spinless fermions in two dimensions. After the scaling theory of localisation, it was commonly accepted that there was no metal in two dimensions. This idea has been challenged by the observation of a metal-insulator transition in low density electron gas (Kravchenko et al. 1994). We propose a scenario in which a metallic phase occurs between the Anderson insulator and the pinned Wigner crystal. This intermediate phase is characterized by an alignment of the local currents flowing in the system. (author)

  12. Proposal of the meson theory by Hideki Yukawa

    International Nuclear Information System (INIS)

    In 1935 Hideki Yukawa courageously proposed a new field theory of the nuclear forces and predicted the existence of the meson, a particle responsible for the strong interaction. This was during a period when new particles were not welcomed in the domain of physics. Later, the meson theory greatly promoted the advancement of nuclear physics. The theory was verified after the π-meson was discovered in cosmic rays by C.P.Powell, a British physicist. Yukawa was awarded the Nobel Prize in 1949 for his contribution to physics

  13. Anderson localization of spinons in a spin-1/2 antiferromagnetic Heisenberg chain

    OpenAIRE

    Pan, B. Y.; Zhou, S. Y.; Hong, X. C.; Qiu, X; Li, S. Y.

    2012-01-01

    Anderson localization is a general phenomenon of wave physics, which stems from the interference between multiple scattering paths1,2. It was originally proposed for electrons in a crystal, but later was also observed for light3-5, microwaves6, ultrasound7,8, and ultracold atoms9-12. Actually, in a crystal, besides electrons there may exist other quasiparticles such as magnons and spinons. However the search for Anderson localization of these magnetic excitations is rare so far. Here we repor...

  14. Adaptive and self-averaging Thouless-Anderson-Palmer mean-field theory for probabilistic modeling

    DEFF Research Database (Denmark)

    Opper, Manfred; Winther, Ole

    2001-01-01

    We develop a generalization of the Thouless-Anderson-Palmer (TAP) mean-field approach of disorder physics. which makes the method applicable to the computation of approximate averages in probabilistic models for real data. In contrast to the conventional TAP approach, where the knowledge of the...

  15. Tractable approximations for probabilistic models: The adaptive Thouless-Anderson-Palmer mean field approach

    DEFF Research Database (Denmark)

    Opper, Manfred; Winther, Ole

    2001-01-01

    We develop an advanced mean held method for approximating averages in probabilistic data models that is based on the Thouless-Anderson-Palmer (TAP) approach of disorder physics. In contrast to conventional TAP. where the knowledge of the distribution of couplings between the random variables is...

  16. Light meson radial Regge trajectories

    OpenAIRE

    Badalian, A.M.; Bakker, B. L. G.; Simonov, Yu. A.

    2002-01-01

    A new physical mechanism is suggested to explain the universal depletion of high meson excitations. It takes into account the appearance of holes inside the string world sheet due to $q\\bar{q}$ pair creation when the length of the string exceeds the critical value $R_1 \\simeq 1.4$ fm. It is argued that a delicate balance between large $N_c$ loop suppression and a favorable gain in the action, produced by holes, creates a new metastable (predecay) stage with a renormalized string tension which...

  17. ν' meson as pseudoscalar gluonium

    International Nuclear Information System (INIS)

    The problem of the ν' meson as a pseudoscalar gluonium within the systematic approach to the resonance physics is considered. QCD sum rules induced by the current Gsub(μν)sup(α)Gsub(μν)sup(α) tilde constructed form gluon field operators are derived. By saturating the sum rules the ν' rough estimates fro the ν' mass and its residue are given. The difference between the ν' and typical quark states such as the rho is noted. Breaking of the operator expansion by the instanton effects is discussed

  18. Properties of c meson

    Indian Academy of Sciences (India)

    Ajay Kumar Rai; P C Vinodkumar

    2006-05-01

    The mass spectrum of $c\\bar{b}$ meson is investigated with an effective quark-antiquark potential of the form $\\dfrac{-_{c}}{r} + Ar^{}$ with varying from 0.5 to 2.0. The and -wave masses, pseudoscalar decay constant, weak decay partial widths in spectator model and the lifetime of c meson are computed. The properties calculated here are found to be in good agreement with other theoretical and experimental values at potential index, = 1.

  19. Transversity and Meson Photoproduction

    CERN Document Server

    Goldstein, G R; Goldstein, Gary R.; Gamberg, Leonard

    2002-01-01

    Both meson photoproduction and semi-inclusive deep inelastic scattering can potentially probe transversity in the nucleon. We explore how that potential can be realized dynamically. The role of rescattering in both exclusive and inclusive meson production as a source for transverse polarization asymmetry is examined. We use a dynamical model to calculate the asymmetry and relate that to the transversity distribution of the nucleon.

  20. Nuclear matter with constituent meson quanta

    International Nuclear Information System (INIS)

    The authors discuss some nonperturbative techniques of field theory, where they dress nuclear matter as a whole with off-mass-shell pions. Here s-wave pion pairs simulate the effect of σ-meson of the mean field approach of Walecka. The signatures are in agreement with earlier results along with new physical insight

  1. Chiral dynamics of heavy-light mesons

    International Nuclear Information System (INIS)

    This thesis focuses on the physics of heavy-light mesons, i.e. quark-antiquark systems composed of a heavy (c or b) and a light (u, d or s) quark. The light-quark sector is treated within the framework of chiral effective field theory. Recent lattice QCD computations have progressed in determining the decay constants of charmed mesons and the scattering lengths of Nambu-Goldstone bosons (pions, kaons) off D mesons. These computations are performed for light quark masses larger than the physical ones. A chiral extrapolation down to physical masses is necessary. It is commonly performed using chiral perturbation theory. The related systematical uncertainties have to be examined carefully. In this thesis it is shown how these uncertainties can be reduced significantly by taking into account relativistic effects in the chiral extrapolations. As a byproduct, estimates are presented for several physical quantities that are related by heavy-quark spin and flavor symmetry. Furthermore, the investigation of the light-quark mass dependence of the scattering lengths of Nambu-Goldstone bosons off D mesons provides important information on the nature of one of the intriguing newly discovered resonances, the D*s0(2317). It is shown that this resonance can be dynamically generated from the coupled-channels DK interaction without a priori assumption of its existence. Finally we demonstrate how the underlying framework, unitarized chiral perturbation theory, can be improved by the inclusion of intermediate states with off-the-mass-shell kinematics.

  2. Light $O^{++}$ Mesons: Scalargators in Florida

    CERN Document Server

    Pennington, M R

    2010-01-01

    Light scalar mesons abound in hadron processes, like the alligators in the Florida Everglades. Moreover, scalars are intimately tied to the vacuum structure of QCD. They are the product of many decays. Consequently, a rich source of recent information about them has come from experiments producing heavy flavour mesons. Indeed, scalars will continue to dominate many of the processes to be studied at forthcoming facilities like BESIII in Beijing, FAIR at GSI Darmstadt and the GlueX experiment at JLab, making an understanding (or at least an excellent and theoretically consistent description) essential for the physics missions of these facilities.

  3. Light O++ Mesons: Scalargators in Florida

    International Nuclear Information System (INIS)

    Light scalar mesons abound in hadron processes, like the alligators in the Florida Everglades. Moreover, scalars are intimately tied to the vacuum structure of QCD. They are the product of many decays. Consequently, a rich source of recent information about them has come from experiments producing heavy flavour mesons. Indeed, scalars will continue to dominate many of the processes to be studied at forthcoming facilities like BESIII in Beijing, FAIR at GSI Darmstadt and the GlueX experiment at JLab, making an understanding (or at least an excellent and theoretically consistent description) essential for the physics missions of these facilities.

  4. Anderson introduces a new biomass baler

    Energy Technology Data Exchange (ETDEWEB)

    D' amour, L.; Lavoie, F. [Anderson Group Co., Chesterville, PQ (Canada)

    2010-07-01

    Canadian-based Anderson Group Company has developed an innovative round baler for harvesting a large variety of woody biomass. The baler was initially developed in 2005 in collaboration with the University Laval and Agriculture and Agri-Food Canada. The third generation BIOBALER{sup TM} is currently built, engineered and commercialized by Anderson. It can produce up to 40 bales/hr in short rotations woody crops such as willow and hybrid poplar. The unit can harvest brushes up to 125 mm in diameter. A standard tractor can pull the BIOBALER in fallow or abandoned land, under power transmission lines, and between planted trees. The patented BIOBALER includes a mulcher head attachment, a choice of long or short swivel tongue, a fixed chamber and an undercarriage frame.

  5. Quantum correlations in B and K meson systems

    CERN Document Server

    Banerjee, Subhashish; MacKenzie, Richard

    2014-01-01

    We study quantum correlations in meson-antimeson systems, as provided for example in meson factories used mainly to probe physics beyond the Standard Model of particle physics. We use a semigroup formalism to compute a trace-preserving density matrix for these systems, in spite of the fact that the particles are unstable. This is used to compute the time evolution of several measures of quantum correlations for three meson systems (KKbar, BdBdbar and BsBsbar). We find that the quantum correlations for these systems can be non-trivially different from their stable counterparts.

  6. ρ meson decays of heavy hybrid mesons

    Science.gov (United States)

    Zhang, Liang; Huang, Peng-Zhi

    2016-07-01

    We calculate the ρ meson couplings between the heavy hybrid doublets Hh/Sh/Mh/Th and the ordinary qQ̅ doublets in the framework of the light-cone QCD sum rule. The sum rules obtained rely mildly on the Borel parameters in their working regions. The resulting coupling constants are rather small in most cases. Supported by National Natural Science Foundation of China (11105007)

  7. Universal mechanism for Anderson and weak localization.

    Science.gov (United States)

    Filoche, Marcel; Mayboroda, Svitlana

    2012-09-11

    Localization of stationary waves occurs in a large variety of vibrating systems, whether mechanical, acoustical, optical, or quantum. It is induced by the presence of an inhomogeneous medium, a complex geometry, or a quenched disorder. One of its most striking and famous manifestations is Anderson localization, responsible for instance for the metal-insulator transition in disordered alloys. Yet, despite an enormous body of related literature, a clear and unified picture of localization is still to be found, as well as the exact relationship between its many manifestations. In this paper, we demonstrate that both Anderson and weak localizations originate from the same universal mechanism, acting on any type of vibration, in any dimension, and for any domain shape. This mechanism partitions the system into weakly coupled subregions. The boundaries of these subregions correspond to the valleys of a hidden landscape that emerges from the interplay between the wave operator and the system geometry. The height of the landscape along its valleys determines the strength of the coupling between the subregions. The landscape and its impact on localization can be determined rigorously by solving one special boundary problem. This theory allows one to predict the localization properties, the confining regions, and to estimate the energy of the vibrational eigenmodes through the properties of one geometrical object. In particular, Anderson localization can be understood as a special case of weak localization in a very rough landscape. PMID:22927384

  8. Factorization for hard exclusive electroproduction of mesons in QCD

    International Nuclear Information System (INIS)

    We formulate and prove a QCD factorization theorem for hard exclusive electroproduction of mesons in QCD. The proof is valid for the leading power in Q and all logarithms. This generalizes previous work on vector meson production in the diffractive region of small x. The amplitude is expressed in terms of off-diagonal generalizations of the usual parton densities. The full theorem applies to all kinds of mesons and not just to vector mesons. The parton densities used include not only the ordinary parton density, but also the helicity density (g1 or Δq) and the transversity density (h1 or δq), and these can be probed by measuring the polarization of the produced mesons with unpolarized protons. copyright 1997 The American Physical Society

  9. Rapidity resummation for $B$-meson wave functions

    CERN Document Server

    Shen, Yue-Long

    2014-01-01

    Transverse-momentum dependent (TMD) hadronic wave functions develop light-cone divergences under QCD corrections, which are commonly regularized by the rapidity $\\zeta$ 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 \\t...

  10. Meson spectroscopy in the light quark sector

    International Nuclear Information System (INIS)

    Understanding the hadron spectrum is one of the fundamental issues in modern particle physics. We know that existing hadron configurations include baryons, made of three quarks, and mesons, made of quark-antiquark pairs. However most of the mass of the hadrons is not due to the mass of these elementary constituents but to their binding force. Studying the hadron spectrum is therefore a tool to understand one of the fundamental forces in nature, the strong force, and Quantum Chromo Dynamics (QCD), the theory that describes it. This investigation can provide an answer to fundamental questions as what is the origin of the mass of hadrons, what is the origin of quark confinement, what are the relevant degrees of freedom to describe these complex systems and how the transition between the elementary constituents, quarks and gluons, and baryons and mesons occurs. In this field a key tool is given by meson spectroscopy. Mesons, being made by a quark and an anti-quark, are the simplest quark bound system and therefore the ideal benchmark to study the interaction between quarks and understand what the role of gluons is. In this investigation, it is fundamental to precisely determine the spectrum and properties of mesons but also to search for possible unconventional states beyond the qq-bar configuration as tetra-quarks (qq q-bar q-bar), hybrids (qq-bar g) and glueballs. These states can be distinguished unambiguously from regular mesons when they have exotic quantum numbers, i.e. combinations of total angular momentum, spin and parity that are not allowed for qq-bar states. These are called exotic quantum numbers and the corresponding states are referred to as exotics. The study of the meson spectrum and the search for exotics is among the goals of several experiments in the world that exploit different reaction processes, as e+e- annihilation, pp-bar annihilation, pion scattering, proton-proton scattering and photo-production, to produce meson states. This intense effort

  11. Holographic meson melting

    International Nuclear Information System (INIS)

    The plasma phase at high temperatures of a strongly coupled gauge theory can be holographically modelled by an AdS black hole. Matter in the fundamental representation and in the quenched approximation is introduced through embedding D7-branes in the AdS-Schwarzschild background. Low spin mesons correspond to the fluctuations of the D7-brane world volume. As is well known by now, there are two different kinds of embeddings, either reaching down to the black hole horizon or staying outside of it. In the latter case the fluctuations of the D7-brane world volume represent stable low spin mesons. In the plasma phase we do not expect mesons to be stable but to melt at sufficiently high temperature. We model the late stages of this meson melting by the quasinormal modes of D7-brane fluctuations for the embeddings that do reach down to the horizon. The inverse of the imaginary part of the quasinormal frequency gives the typical relaxation time back to equilibrium of the meson perturbation in the hot plasma. We briefly comment on the possible application of our model to quarkonium suppression

  12. Static-light meson-meson potentials

    CERN Document Server

    Bali, Gunnar

    2010-01-01

    We investigate potentials between pairs of static-light mesons in Nf=2 Lattice QCD, in different spin channels. The question of attraction and repulsion is particularly interesting with respect to the X(3872) charmonium state and charged candidates such as the Z+(4430). We employ the nonperturbatively improved Sheikholeslami-Wohlert fermion and the Wilson gauge actions at a lattice spacing a approx. 0.084 fm and a pseudoscalar mass mPS approx. 760 MeV. We use stochastic all-to-all propagator techniques, improved by a hopping parameter expansion. The analysis is based on the variational method, utilizing various source and sink interpolators.

  13. Search for scalar mesons

    International Nuclear Information System (INIS)

    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

  14. Evaluating the Anderson-Darling Distribution

    Directory of Open Access Journals (Sweden)

    George Marsaglia

    2004-02-01

    Full Text Available Except for n = 1, only the limit as n approaches infinity for the distribution of the Anderson-Darling test for uniformity has been found, and that in so complicated a form that published values for a few percentiles had to be determined by numerical integration, saddlepoint or other approximation methods. We give here our method for evaluating that asymptotic distribution to great accuracy--directly, via series with two-term recursions. We also give, for any particular n, a procedure for evaluating the distribution to the fourth digit, based on empirical CDF's from samples of size 1010 .

  15. Anderson localization of light with topological dislocations

    CERN Document Server

    Lobanov, Valery E; Vysloukh, Victor A; Torner, Lluis

    2013-01-01

    We predict Anderson localization of light with nested screw topological dislocations propagating in disordered two-dimensional arrays of hollow waveguides illuminated by vortex beams. The phenomenon manifests itself in the statistical presence of topological dislocations in ensemble-averaged output distributions accompanying standard disorder-induced localization of light spots. Remarkably, screw dislocations are captured by the light spots despite the fast and irregular transverse displacements and topological charge flipping undertaken by the dislocations due to the disorder. The statistical averaged modulus of the output local topological charge depends on the initial vorticity carried by the beam.

  16. The {eta}' meson from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Michael, C. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Urbach, C. [Humboldt Univ. Berlin (Germany). Inst. fuer Elementarteilchenphysik

    2008-04-15

    We study the flavour singlet pseudoscalar mesons from first principles using lattice QCD. With N{sub f}=2 flavours of light quark, this is the so-called {eta}{sub 2} meson and we discuss the phenomenological status of this. Using maximally twisted-mass lattice QCD, we extract the mass of the {eta}{sub 2} meson at two values of the lattice spacing for lighter quarks than previously discussed in the literature. We are able to estimate the mass value in the limit of light quarks with their physical masses. (orig.)

  17. Nuclear physics accelerator facilities

    International Nuclear Information System (INIS)

    Brief descriptions are given of DOE and Nuclear Physics program operated and sponsored accelerator facilities. Specific facilities covered are the Argonne Tandem/Linac Accelerator System, the Tandem/AGS Heavy Ion Facility at Brookhaven National Laboratory, the proposed Continuous Beam Accelerator at Newport News, Virginia, the Triangle Universities Nuclear Laboratory at Duke University, the Bevalac and the SuperHILAC at Lawrence Berkeley Laboratory, the 88-Inch Cyclotron at Lawrence Berkeley Laboratory, the Clinton P. Anderson Meson Physics Facility at Los Alamos National Laboratory, the Bates Linear Accelerator Center at Massachusetts Institute of Technology, the Holifield Heavy Ion Research Facility at Oak Ridge National Laboratory, the Nuclear Physics Injector at Stanford Linear Accelerator Center, the Texas A and M Cyclotrons, the Tandem/Superconducting Booster Accelerator at the University of Washington and the Tandem Van de Graaff at the A.W. Wright Nuclear Structure Laboratory of Yale University. Included are acquisition cost, research programs, program accomplishments, future directions, and operating parameters of each facility

  18. {eta} meson photoproduction on deuterium; Photoproduction du meson {eta} sur le deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann-Rothe, P.

    1996-05-30

    Measurements of the total and differential cross sections for {eta}-meson photoproduction on a D{sub 2} liquid target from threshold to 1.2 GeV, have been taken using the tagged Bremsstrahlung photon beam produced by the electrons extracted from the ELSA storage ring at Bonn. The reaction was identified by detecting the eta decay products in the neutral meson spectrometer SPES0-2{pi}, while the recoil baryons (proton, neutron or deuteron) were detected by a variety of large angle scintillator detectors. We succeeded to identify completely the final states corresponding to the production of an {eta} meson on a Quasi-Free (QF) proton, a QF neutron and the coherent deuteron. The differential cross sections corresponding to the production of a coherent deuteron n the final state have been measured, from threshold to 800 MeV; they are 6 times smaller the only previous measurement reported by Anderson and Prepost in 1969. This is consistent with an Isoscalar part of the Amplitude much smaller than the Isovector one. The differential cross sections are in good agreement with the theoretical prediction on the impulse approximation mechanism; indicating in particular, fairly small contributions from rescattering terms. A direct measurement of the neutron to proton cross section ratios has been obtained by integrating the counting rates on the corresponding QF peaks and is 0.70 {+-} 0.03, from 700 MeV to 900 MeV, with a small angular dependence. These two results by comparison to the measured free proton data should allow to reconstruct the free neutron cross sections in a rather model-independent way. (authors). 56 refs., 90 figs., 13 tabs.

  19. Techniques in meson spectroscopy

    International Nuclear Information System (INIS)

    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

  20. Glueball-meson mixing

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  1. Distribution of critical temperature at Anderson localization

    Science.gov (United States)

    Gammag, Rayda; Kim, Ki-Seok

    2016-05-01

    Based on a local mean-field theory approach at Anderson localization, we find a distribution function of critical temperature from that of disorder. An essential point of this local mean-field theory approach is that the information of the wave-function multifractality is introduced. The distribution function of the Kondo temperature (TK) shows a power-law tail in the limit of TK→0 regardless of the Kondo coupling constant. We also find that the distribution function of the ferromagnetic transition temperature (Tc) gives a power-law behavior in the limit of Tc→0 when an interaction parameter for ferromagnetic instability lies below a critical value. However, the Tc distribution function stops the power-law increasing behavior in the Tc→0 limit and vanishes beyond the critical interaction parameter inside the ferromagnetic phase. These results imply that the typical Kondo temperature given by a geometric average always vanishes due to finite density of the distribution function in the TK→0 limit while the typical ferromagnetic transition temperature shows a phase transition at the critical interaction parameter. We propose that the typical transition temperature serves a criterion for quantum Griffiths phenomena vs smeared transitions: Quantum Griffiths phenomena occur above the typical value of the critical temperature while smeared phase transitions result at low temperatures below the typical transition temperature. We speculate that the ferromagnetic transition at Anderson localization shows the evolution from quantum Griffiths phenomena to smeared transitions around the critical interaction parameter at low temperatures.

  2. Light Scalar Mesons in Photon-Photon Collisions

    OpenAIRE

    Achasov, N. N.; Shestakov, G. N.

    2009-01-01

    The light scalar mesons, discovered over forty years ago, became a challenge for the naive quark-antiquark model from the outset. At present the nontrivial nature of these states is no longer denied practically anybody. Two-photon physics has made a substantial contribution to understanding the nature of the light scalar mesons. Recently, it entered a new stage of high statistics measurements. We review the results concerning two-photon production mechanisms of the light scalars, based on the...

  3. Anderson transition in the three dimensional symplectic universality class

    OpenAIRE

    Asada, Yoichi; Slevin, Keith; Ohtsuki, Tomi

    2004-01-01

    We study the Anderson transition in the SU(2) model and the Ando model. We report a new precise estimate of the critical exponent for the symplectic universality class of the Anderson transition. We also report numerical estimation of the $\\beta$ function.

  4. Controlling Anderson localization in disordered photonic crystal waveguides

    DEFF Research Database (Denmark)

    Garcia-Fernández, David; Smolka, Stephan; Stobbe, Søren; Lodahl, Peter

    2010-01-01

    In most experiments on Anderson localization so far, only completely random systems without any long-range correlation between the scattering sites have been used, meaning that the Anderson localized modes cannot be controlled. Strongly confined modes were recently observed in the slow-light regime...

  5. Controlling Anderson localization in disordered photonic crystal waveguides

    DEFF Research Database (Denmark)

    Garcia-Fernández, David; Smolka, Stephan; Stobbe, Søren;

    2010-01-01

    In most experiments on Anderson localization so far, only completely random systems without any long-range correlation between the scattering sites have been used, meaning that the Anderson localized modes cannot be controlled. Strongly confined modes were recently observed in the slow-light regime...... of a disordered photonic crystal waveguide and attributed to Anderson localization. We have tested this hypothesis by measuring the light localization length, ξloc, in a disordered photonic crystal waveguide and checked explicitly the criterion of one dimensional Anderson localization that ξloc is...... shorter than the waveguide length LS. Our measurements demonstrate for the first time the close relation between light localization and density of states, which can be used ultimately for controlling Anderson localized modes....

  6. Tractable approximations for probabilistic models: The adaptive Thouless-Anderson-Palmer mean field approach

    OpenAIRE

    Opper, Manfred; Winther, Ole

    2001-01-01

    We develop an advanced mean held method for approximating averages in probabilistic data models that is based on the Thouless-Anderson-Palmer (TAP) approach of disorder physics. In contrast to conventional TAP. where the knowledge of the distribution of couplings between the random variables is required. our method adapts to the concrete couplings. We demonstrate the validity of our approach, which is so far restricted to models with nonglassy behavior? by replica calculations for a wide clas...

  7. Exclusive and inclusive decays of B mesons into Ds mesons

    International Nuclear Information System (INIS)

    We have studied the production of Ds mesons in the decays of B mesons at the Υ(4S) resonance. We report on the first observation of exclusive B-meson decays B→Ds-D*+, B→Ds-D+, and B→Ds-D0. We also present a new measurement of the branching ratio and the momentum spectrum for the inclusive decay B→DsX

  8. Effect of changes in meson properties in a nuclear medium - $J/\\Psi$ dissociation in nuclear matter, and meson-nucleus bound states

    OpenAIRE

    Tsushima, K.; Sibirtsev, A.; Saito, K.; A.W. Thomas; Lu, D.H.

    2000-01-01

    We discuss the effect of changes in meson properties in a nuclear medium on physical observables, notably, $J/\\Psi$ dissociation on pion and $\\rho$ meson comovers in relativistic heavy ion collisions, and the prediction of the $\\omega$-, $\\eta$- and $\\eta'$-nuclear bound states.

  9. Kolmogorov turbulence, Anderson localization and KAM integrability

    Science.gov (United States)

    Shepelyansky, D. L.

    2012-06-01

    The conditions for emergence of Kolmogorov turbulence, and related weak wave turbulence, in finite size systems are analyzed by analytical methods and numerical simulations of simple models. The analogy between Kolmogorov energy flow from large to small spacial scales and conductivity in disordered solid state systems is proposed. It is argued that the Anderson localization can stop such an energy flow. The effects of nonlinear wave interactions on such a localization are analyzed. The results obtained for finite size system models show the existence of an effective chaos border between the Kolmogorov-Arnold-Moser (KAM) integrability at weak nonlinearity, when energy does not flow to small scales, and developed chaos regime emerging above this border with the Kolmogorov turbulent energy flow from large to small scales.

  10. Plea for European Price Anderson legislation

    International Nuclear Information System (INIS)

    The paper analyses the essential features and the basic differences in nuclear liability and coverage in the United States where the problem is governed by the Price-Anderson legislation, and the Member States of the European Community which adhere to the Paris Convention on Third Party Liability in the Field of Nuclear Energy. The paper undertakes to show that it is possible to introduce into the European Community certain elements of the American regime, in particular the solidarity of nuclear operators and the retroactive premium coverage without violating the basic principles of the Paris Convention. Consequently the paper advocates the adoption of such rules in Europe as a step towards harmonisation of nuclear coverage and safety and a means to reduce government interference. (author)

  11. Anderson localization and momentum-space entanglement

    International Nuclear Information System (INIS)

    We consider Anderson localization and the associated metal–insulator transition for non-interacting fermions in D = 1, 2 space dimensions in the presence of spatially correlated on-site random potentials. To assess the nature of the wave function, we follow a recent proposal to study momentum-space entanglement. For a D = 1 model with long-range disorder correlations, both the entanglement spectrum and the entanglement entropy allow us to clearly distinguish between extended and localized states based upon a single realization of disorder. However, for other models, including the D = 2 case with long-range correlated disorder, we find that the method is not similarly successful. We analyze the reasons for its failure, concluding that the much desired generalization to higher dimensions may be problematic. (paper)

  12. Slow Relaxation in Anderson Critical Systems

    Science.gov (United States)

    Choi, Soonwon; Yao, Norman; Choi, Joonhee; Kucsko, Georg; Lukin, Mikhail

    2016-05-01

    We study the single particle dynamics in disordered systems with long range hopping, focusing on the critical cases, i.e., the hopping amplitude decays as 1 /rd in d-dimension. We show that with strong on-site potential disorder, the return probability of the particle decays as power-law in time. As on-site potential disorder decreases, the temporal profile smoothly changes from a simple power-law to the sum of multiple power-laws with exponents ranged from 0 to νmax. We analytically compute the decay exponents using a simple resonance counting argument, which quantitatively agrees with exact numerical results. Our result implies that the dynamics in Anderson Critical systems are dominated by resonances. Harvard-MIT CUA, Kwanjeong Educational Fellowship, AFOSR MURI, Samsung Scholarship.

  13. Anderson Exploration Ltd. 1998 annual report

    International Nuclear Information System (INIS)

    In 1998, Anderson Exploration's undeveloped land inventory in the western provinces decreased 7% to 3,183,000 net acres largely due to lease expiries and drilling activity. The undeveloped land base is located 63% in Alberta, 19% in British Columbia, 17% in Saskatchewan, and 1% in Manitoba. During 1998, Anderson Exploration participated in drilling 446 wells for oil and gas vs. 669 for 1997. The average working interest in the wells was 63% vs. 64% in 1997. In 1998, the company spent $109 million on the construction of field gathering systems and production facilities vs. $123 million in 1997. In 1998, the company's gas sales increased to 555 million cubic feet per day from 549 million cubic feet per day in 1997. Crude oil sales averaged 29,808 barrels per day in 1998, an increase of 9% over the 1997 production. In 1998, the company replaced 148% of production with proven reserve additions, net of revisions, by spending 163% of cash flow from operations on capital spending. After a volatile year in 1 997, natural gas prices stabilized somewhat in 1998. A modest price increase was experienced in 1997. The company's average plant gate natural gas price increased modestly in 1998 to $1.94 per thousand cubic feet, marking the 3rd consecutive price increase. The company owns an average interest of 10.4% in two straddle plants at Empress, Alberta. The company operates and is a 50% owner of Federated Pipe Lines Ltd. The company is committed to protecting the health and safety of all employees and the public, as well as preserving the quality of the environment

  14. Decays of B mesons

    International Nuclear Information System (INIS)

    According to the Standard Model of six quarks and six leptons, the charged-current decays of quarks can couple any of the up quarks, u, c, or t, to any of the down quarks, d, s, or b. Several of these couplings can be measured only in B-meson decays. It is important to measure them accurately in order to expand our knowledge of the model, to test its validity, and more importantly, to take us to a formulation of what is beyond. In the paper, the authors review the measurements that have been made on the weak decays of B mesons and discuss their implications for the matrix of quark couplings

  15. Meson Spectroscopy without Tetraquarks

    CERN Document Server

    Bugg, D V

    2011-01-01

    Data on e+e- -> piplus-piminus-Upsilon(1S,2S,3S) show a large increase in branching fractions near Upsilon(10860). A suggestion of Ali et al. is to interpret this as evidence for a tetraquark, Yb(10890) = b-bbar. However, it may also be interpreted in terms of Upsilon(10860) -> B-B*, B*B* and BsB*s above the open-b threshold, followed by de-excitation processes such as $BB* -> Upsilon (1S,2S,3S). In the charm sector, a hypothesis open to experimental test is that X,Y and Z peaks in the mass range 3872 to 3945 MeV may all be due to regular 3P1 and 3P2 c-cbar states (and perhaps 3P0) mixed with meson-meson.

  16. The scalar meson enigma

    International Nuclear Information System (INIS)

    The nature of the scalar mesons in the 1 GeV region is studied. Analysis of all high statistics data in the neighbourhood of Kanti K threshold, in particular the fine-binned spectra on ψ → φ(ππ), φ(Kanti K) from DM2 and Mark III, indicate in an almost model-independent way that the f0(S*) is not a Kanti K molecule. (orig.)

  17. Heavy meson production at HERA

    Directory of Open Access Journals (Sweden)

    Figiel Jan

    2014-01-01

    Full Text Available The copious production of charm mesons at HERA has allowed QCD to be probed in open charm and charm vector meson production. Elastic and proton-dissociatve photoproduction of J/ψ mesons have been measured at HERA. The data are compared to other measurements and the W and t dependences are parametrised using phenomenological fits. The ψ (2S state has also been measured exclusively and the ratio of its production rate to J/ψ mesons presented as a function of the kinematic variables. Inelastic production of J/ψ and ψ(2S mesons gives insight into non-relativistic QCD and final results are presented here. Open charm production has been measured in order to better understand the fragmentation process of charm mesons as well as giving insight into the structure of the proton.

  18. Mass-producing B mesons

    International Nuclear Information System (INIS)

    Since the discovery of the upsilon resonances in 1977 the physics of the fifth quark - beauty - has played a vital role in establishing and consolidating today's Standard Model of particle physics. In recent years, a wealth of data on B particle (containing the beauty quark) has emerged from the detectors ARGUS (at the DORIS ring, DESY, Hamburg) and CLEO (at the Cornell CESR ring) as well as from CERN's LEP electron-positron collider and the proton-antiproton colliders at CERN and Fermilab. But the most challenging goal of this physics is to explore the mystery of CP violation, so far only seen in neutral kaon decays. This subtle mechanism - a disregard for the combined symmetry of particle antiparticle switching and left-right reflection - possibly moulded the evolution of the Universe after the Big Bang, providing a world dominated by matter, rather than one where matter and antimatter play comparable roles. To fully explore CP violation in the laboratory needs a dedicated machine - a particle 'factory' - to mass produce B mesons. Only when this full picture of CP violation has been revealed will physicists finally be able to solve its mysteries. As well as major proposals in the US and Japan, several ideas have been launched in Europe. Over the years, many working groups have accumulated an impressive amount of data and knowledge on the physics as well as on the machine and detectors. The spearheads of experimental B physics are the ARGUS and CLEO collaborations. Highlights include the determination of the parameters of the (Cabibbo-Kobayashi-Maskawa, CKM) quark mixing matrix, testing the consistency of the Standard Model with six quarks and three leptons, and giving the first indirect hint that the as yet unseen sixth ('top') quark is very heavy, together with initial indications of how it should decay. Valuable complementary information has come from proton-antiproton collider data and particularly from the LEP experiments at the

  19. Future prospects for exotic mesons

    International Nuclear Information System (INIS)

    A brief description is given of the current status of exotic mesons produced in π-p interactions at 18 GeV/c-carried out with the BNL multiparticle spectrometer. The next logical step in our endeavor to understand the gluonic degrees of freedom in mesons is to extend the search for exotic mesons with hidden strangeness in K-p interactions at beam momenta in the range 15 to 25 GeV/c. (orig.)

  20. Heavy meson in nuclear medium

    CERN Document Server

    Tolos, L; Garcia-Recio, C; Molina, R; Nieves, J; Oset, E; Ramos, A

    2010-01-01

    The properties of charmed mesons in dense matter are studied using a unitary coupled-channel approach in the nuclear medium which takes into account Pauli-blocking effects and meson self-energies in a self-consistent manner. We obtain the open-charm meson spectral functions in this dense nuclear environment, and discuss their implications on hidden charm and charm scalar resonances and on the formation of $D$-mesic nuclei at FAIR.

  1. Studies in medium energy physics

    International Nuclear Information System (INIS)

    This document constitutes the (1991--1992) technical progress report and continuation proposal for the ongoing medium energy nuclear physics research program supported by the US Department of Energy through special Research Grant DE-FG05-88ER40444. The experiments discussed are conducted at the Los Alamos National Laboratory's (LANL) Clinton P. Anderson Meson Physics Facility (LAMPF) and the Alternating Gradient Synchrotron (AGS) facility of the Brookhaven National Laboratory (BNL). The overall motivation for the work discussed in this document is driven by three main objectives: (1) provide hadron-nucleon and hadron-nucleus scattering data which serve to facilitate the study of effective two-body interactions, test (and possibly determine) nuclear structure, and help study reaction mechanisms and dynamics; (2) provide unique, first-of-a-kind ''exploratory'' hadron-nucleus scattering data in the hope that such data will lead to discovery of new phenomena and new physics; and (3) perform precision tests of fundamental interactions, such as rare decay searches, whose observation would imply fundamental new physics

  2. Charmed mesons in nuclear matter

    CERN Document Server

    Tolos, L; Garcia-Recio, C; Oset, E; Molina, R; Nieves, J; Ramos, A

    2010-01-01

    We obtain the properties of charmed mesons in dense matter using a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner. We study the behaviour of dynamically-generated baryonic resonances together with the open-charm meson spectral functions in this dense nuclear environment. We discuss the implications of the in-medium properties of open-charm mesons on the $D_{s0}(2317)$ and the predicted X(3700) scalar resonances, and on the formation of $D$-mesic nuclei.

  3. The Discovery of Anti-Matter The Autobiography of Carl David Anderson, the Youngest Man to Win the Nobel Prize

    CERN Document Server

    1999-01-01

    In 1936, at age 31, Carl David Anderson became the second youngest Nobel laureate for his discovery of antimatter when he observed positrons in a cloud chamber.He is responsible for developing rocket power weapons that were used in World War II.He was born in New York City in 1905 and was educated in Los Angeles. He served for many years as a physics professor at California Institute of Technology. Prior to Oppenheimer, Anderson was offered the job of heading the Los Alamos atomic bomb program but could not assume the role because of family obligations.He was a pioneer in studying cosmic rays

  4. Charm physics: theoretical review

    OpenAIRE

    Petrov, Alexey A.

    2003-01-01

    We review recent developments in charm physics, focusing on the physics of charmed mesons. We discuss charm spectroscopy, decay constants, as well as searches for new physics with charmed mesons. We discuss D0-anti-D0 mixing and CP-violation in charm decays. We also present the modified Nelson plot of charm mixing predictions.

  5. High-energy exclusive leptoproduction of vector mesons

    International Nuclear Information System (INIS)

    The physics of diffractive vector meson production in virtual photon nucleon scattering at NMC energies is reviewed. A particular attention is paid to the physical aspects of the reaction and how they influence the observables. The reaction is a good probe to investigate both soft exchange mechanisms and hadronic wave functions. Extension to either HERA or ELFE kinematics is sketched out. (orig.)

  6. Glueballs and vector mesons at NICA

    CERN Document Server

    Parganlija, Denis

    2016-01-01

    Two interconnected fields of interest are suggested for NICA. Firstly, existence of glueballs is predicted by the theory of strong interaction but -- even after decades of research -- glueball identification in the physical spectrum is still unclear. NICA can help to ascertain experimental glueball candidates via J/Psi decays whose yield is expected to be large. Importance of glueballs is not limited to vacuum: since they couple to other meson states, glueballs can also be expected to influence signatures of chiral-symmetry restoration in the high-energy phase of strong dynamics. Mass shifting or in-medium broadening of vector and axial-vector mesons may occur there but the extent of such phenomena is still uncertain. Additionally, glueball properties could also be modified in medium. Exploration of these issues is the second suggested field of interest that can be pursued at NICA.

  7. Rotational Spectra of the Baryons and Mesons

    CERN Document Server

    Akers, D

    2003-01-01

    An investigation of the rotational spectra of baryons and mesons is conducted. Diakonov, Petrov and Polyakov claimed that all light baryons are rotational excitations. A study of the history of particle physics indicates that the ideas of rotational spectra can be originally attributed to a constituent-quark (CQ) model as proposed by Mac Gregor. Later research advanced spin-orbit splitting in a deformed model as suggested by Bhaduri and others. In the present work, we show from current data that the rotational spectra of baryons and mesons are in agreement with the original claims of Mac Gregor: namely, the values for the rotational energies Erot of particles merge with those of nuclear rotational bands in light nuclei. It is also shown that particles of different isotopic spins are separated in mass by a 70 MeV quantum, which is related to the SU(3) decuplet mass spacing as originally proposed by Gell-Mann.

  8. The hybrid mesons quest: the MesonEx experiment at Jefferson Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, Alessandro [Univ. of Rome Tor Vergata (Italy)

    2016-03-01

    The meson spectroscopy plays nowadays a central role in the investigation of hadron structure thanks to the possible existence of exotic hybrid mesons, quark-antiquark-gluon bound states. Their explicit gluonic degrees of freedom which should clearly emerge from a Partial Wave Analysis (PWA) of the corresponding Dalitz plot of the exotic particle decay, may result in final JPC configurations not allowed in the constituent quark model. Besides this clear signature, hybrid mesons are also expected to have a large particle multiplicity decays, requiring for their search an experimental apparatus with high performances in terms of rate capability, resolution and almost a full acceptance to apply PWA methods. New-generation experiments are planned at Thomas Jefferson National Laboratory (VA, USA) for which an unprecedented statistics of large multiplicity decay events with fully reconstructed kinematics will be available. In particular for the MesonEx (CLAS12) experiment in Hall B, a wide scientific program that will start in 2016 has been deployed to study the meson spectrum at energies up to 11 GeV. A key role in such program is played by the Forward Tagger apparatus of the experiment, which will allow to extend the study of meson electro-production to very low Q2 values, in a quasi-real photo production kinematical region, where the production of hybrid mesons is expected to be favorite. Currently a new analysis framework for the search of the hybrid mesons is being set up by the HASPECT network, an international structure which gather people involved into theoretical and experimental hadronic physics all over the world. The goals of the network is to develop new analysis models and statistical techniques to unfold the signal and background distributions in high-statistics datasets. In this work are briefly presented the first preliminary results from the application of a statistical technique, namely the sPlot, to the data already acquired by the CLAS experiment for

  9. The hybrid mesons quest: the MesonEx experiment at Jefferson Laboratory

    Science.gov (United States)

    Rizzo, A.; CLAS Collaboration

    2016-02-01

    The meson spectroscopy plays nowadays a central role in the investigation of hadron structure thanks to the possible existence of exotic hybrid mesons, quark-antiquark-gluon bound states. Their explicit gluonic degrees of freedom which should clearly emerge from a Partial Wave Analysis (PWA) of the corresponding Dalitz plot of the exotic particle decay, may result in final JPC configurations not allowed in the constituent quark model. Besides this clear signature, hybrid mesons are also expected to have a large particle multiplicity decays, requiring for their search an experimental apparatus with high performances in terms of rate capability, resolution and almost a full acceptance to apply PWA methods. New-generation experiments are planned at Thomas Jefferson National Laboratory (VA, USA) for which an unprecedented statistics of large multiplicity decay events with fully reconstructed kinematics will be available. In particular for the MesonEx (CLAS12) experiment in Hall B, a wide scientific program that will start in 2016 has been deployed to study the meson spectrum at energies up to 11 GeV. A key role in such program is played by the Forward Tagger apparatus of the experiment, which will allow to extend the study of meson electro-production to very low Q2 values, in a quasi-real photo production kinematical region, where the production of hybrid mesons is expected to be favorite. Currently a new analysis framework for the search of the hybrid mesons is being set up by the HASPECT network, an international structure which gather people involved into theoretical and experimental hadronic physics all over the world. The goals of the network is to develop new analysis models and statistical techniques to unfold the signal and background distributions in high-statistics datasets. In this work are briefly presented the first preliminary results from the application of a statistical technique, namely the sPlot, to the data already acquired by the CLAS experiment for

  10. Nuclear Physics accelerator facilities

    International Nuclear Information System (INIS)

    The Nuclear Physics program requires the existence and effective operation of large and complex accelerator facilities. These facilities provide the variety of projectile beams upon which virtually all experimental nuclear research depends. Their capability determine which experiments can be performed and which cannot. Seven existing accelerator facilities are operated by the Nuclear Physics program as national facilities. These are made available to all the Nation's scientists on the basis of scientific merit and technical feasibility of proposals. The national facilities are the Clinton P. Anderson Meson Physics Facility (LAMPF) at Los Alamos National Laboratory; the Bates Linear Accelerator Center at Massachusetts Institute of Technology; the Bevalac at Lawrence Berkeley Laboratory; the Tandem/AGS Heavy Ion Facility at Brookhaven National Laboratory; the ATLAS facility at Argonne National Laboratory; the 88-Inch Cyclotron at Lawrence Berkeley Laboratory; the Holifield Heavy Ion Research Facility at Oak Ridge National Laboratory. The Nuclear Physics Injector at the Stanford Linear Accelerator Center (SLAC) enables the SLAC facility to provide a limited amount of beam time for nuclear physics research on the same basis as the other national facilities. To complement the national facilities, the Nuclear Physics program supports on-campus accelerators at Duke University, Texas A and M University, the University of Washington, and Yale University. The facility at Duke University, called the Triangle Universities Nuclear Laboratory (TUNL), is jointly staffed by Duke University, North Carolina State University, and the University of North Carolina. These accelerators are operated primarily for the research use of the local university faculty, junior scientists, and graduate students

  11. Exotic mesons: status and future

    OpenAIRE

    Klempt, Eberhard

    2007-01-01

    The evidence for the existence of mesons with exotic quantum numbers and of hybrid candidates with non-exotic quantum numbers is critically reviewed, including candidates with hidden charm. Aims and methods of future searches for hybrid mesons are briefly discussed.

  12. Mesonic theory of effective forces

    International Nuclear Information System (INIS)

    The construction of nucleon-nucleon effective interaction on base of meson theory of nuclear forces is considered. The dependence of effective force parameters from coupling constants and masses of the exchange mesons is investigated. The results of nuclear matter calculations are presented. 36 refs.; 9 figs.; 2 tabs

  13. Exotic meson spectroscopy with CLAS

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. B decays into light mesons

    International Nuclear Information System (INIS)

    The author calculates the form factors describing semileptonic and penguin induced decays of B mesons into light pseudoscalar and vector mesons. The form factors are calculated from QCD sum rules on the light-cone including contributions up to twist 4, radiative corrections to the leading twist contribution and SU(3) breaking effects. The theoretical uncertainty is estimated to be tilde (15--20)%

  15. The light meson spectroscopy program

    Directory of Open Access Journals (Sweden)

    Smith Elton S.

    2014-06-01

    Full Text Available Recent discoveries of a number of unexpected new charmomium-like meson states at the BaBar and Belle B-factories have demonstrated how little is still known about meson spectroscopy. In this talk we will review recent highlights of the light quark spectroscopy from collider and fixed target experiments.

  16. Meson Resonances from Lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-06-01

    There has been recent, significant, advances in the determination of the meson spectrum of QCD. Current efforts have focused on the development and application of finite-volume formalisms that allow for the determination of scattering amplitudes as well as resonance behavior in coupled channel systems. I will review some of these recent developments, and demonstrate the viability of the method in meson systems.

  17. Meson resonances on the lattice

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-06-01

    There has been recent, significant, advances in the determination of the meson spectrum of QCD. Current efforts have focused on the development and application of finite-volume formalisms that allow for the determination of scattering amplitudes as well as resonance behavior in coupled channel systems. I will review some of these recent developments, and demonstrate the viability of the method in meson systems

  18. K^* Mesons and Nucleon Strangeness

    OpenAIRE

    Barz, L. L.; Forkel, H.; Hammer, H. -W.; Navarra, F. S.; Nielsen, M; Ramsey-Musolf, M. J.

    1998-01-01

    We study contributions to the nucleon strange quark vector current form factors from intermediate states containing K^* mesons. We show how these contributions may be comparable in magnitude to those made by K mesons, using methods complementary to those employed in quark model studies. We also analyze the degree of theoretical uncertainty associated with K^* contributions.

  19. The light meson spectroscopy program

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Elton S. [JLAB

    2014-06-01

    Recent discoveries of a number of unexpected new charmomium-like meson states at the BaBar and Belle B-factories have demonstrated how little is still known about meson spectroscopy. In this talk we will review recent highlights of the light quark spectroscopy from collider and fixed target experiments.

  20. Heavy meson fragmentation at LHC

    Directory of Open Access Journals (Sweden)

    M. A. Gomshi Nobary

    2003-06-01

    Full Text Available   Large Hadron Collider (LHC at CERN will provide excellent opportunity to study the production and decay of heavy mesons and baryons with high statistics. We aim at the heavy mesons in this work and calculate their fragmentation functions consistent with this machine and present their total fragmentation probabilities and average fragmentation parameters.

  1. Lifetimes of charmed mesons

    International Nuclear Information System (INIS)

    Using the ARGUS detector at the e+e- storage ring DORIS II at DESY, we have measured the lifetimes of the D0, D+ and Ds+ mesons. We find τsub(D0) = (4.8±0.4±0.3)x10-13 s, τsub(D+) = (10.5±0.8±0.7)x10-13 s and τsub(Ds+) = (5.6-1.2+1.3±0.8)x10.13s. (orig.)

  2. Photoproduction of Hybrid Mesons

    OpenAIRE

    Barnes, T.

    1999-01-01

    In this contribution I discuss prospects for photoproducing hybrid mesons at CEBAF, based on recent model results and experimental indications of possible hybrids. One excellent opportunity appears to be a search for the I=1, JPC=2+-, neutral "(b2)o" hybrid in (a2 pi)o through diffractive photoproduction. Other notable possibilities accessible through pi+ or pio exchange photoproduction are I=1, JPC=1-+, charged "pi1+" in f1 pi+, (b1 pi)+ and (rho pi)+; piJ(1770)+ in f2 pi+ and (b1 pi)+; pi(1...

  3. Variation of ground state Bc and B*c meson masses for various n values

    International Nuclear Information System (INIS)

    One of the most challenging field in theoretical particle physics is heavy quark physics. The huge amount of data available on hadrons needs to be explained in order to explore this field. Experimentally if one finds the need of high energy particles that can probe quark level physics, theoretically a suitable model is required to explain the properties such as mass spectrum, decays, reaction mechanism and bound state behaviours of those mesons which involve these quarks. In this line Bc meson is of significance when compared to flavour symmetric cc¯ and bb¯ meson states because it is the only meson composed of a b-quark and c¯ quark and is the first particle containing both b and c quarks. The Bc is the lowest mass bound state of c and b quarks which is expected to be a pseudo scalar meson predicted by the Standard Model

  4. The UTfit collaboration average of D meson mixing data: Winter 2014

    International Nuclear Information System (INIS)

    We update the analysis of D meson mixing including the latest experimental results as of January 2014. We derive constraints on the parameters M12, Γ12 and Φ12 that describe D meson mixing using all available data, allowing for CP violation. We also provide posterior distributions for observable parameters appearing in D physics

  5. Numerical verification of universality for the Anderson transition

    OpenAIRE

    Slevin, Keith; Ohtsuki, Tomi

    2001-01-01

    We analyze the scaling behavior of the higher Lyapunov exponents at the Anderson transition. We estimate the critical exponent and verify its universality and that of the critical conductance distribution for box, Gaussian and Lorentzian distributions of the random potential.

  6. Controlling Anderson localization in disordered photonic crystal waveguides

    DEFF Research Database (Denmark)

    Garcia-Fernández, David; Smolka, Stephan; Stobbe, Søren;

    structures [1,2]. Originally proposed for electrons by P. W. Anderson [3], only completely random systems without any long-range correlation between the scattering sites have been used so far, meaning that the Anderson-localized modes cannot be controlled. In disordered photonic crystals, these modes are...... predicted to appear at frequencies in or near a band gap [4] providing a possible way to control Anderson-localized modes. We have tested this hypothesis by measuring the light localization length, ξ, in a disordered photonic crystal waveguide (PCW) as a function of the dispersive slowdown factor of light...... of the waveguide. Our measurements demonstrate for the first time the close relation between light localization and density of states [5], which can be used ultimately for controlling the extension and spectral position of Anderson-localized modes....

  7. Martin Anderson valis "Joonase lähetamise" / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    2000-01-01

    M. Anderson kommenteeris ameerika muusikaajakirjas "Fanfare" viit talle kõige enam mõju avaldanud heliplaati, sh. R. Tobiase oratooriumi "Joonase lähetamine" CD-plaati (BIS). M. Andersoni huvist eesti muusika vastu

  8. Cavity quantum electrodynamics in the Anderson-localized regime

    DEFF Research Database (Denmark)

    Sapienza, Luca; Nielsen, Henri Thyrrestrup; Stobbe, Søren;

    2010-01-01

    We experimentally measure, by means of time-resolved photoluminescence spectroscopy, a 15-fold enhancement of the spontaneous emission decay rate of single semiconductor quantum dots coupled to disorder-induced Anderson-localized modes with efficiencies reaching 94%....

  9. 2011 South Carolina DNR Lidar: Tricounty (Anderson, Oconee, Pickens)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Towill Inc. collected LiDAR for over 3,500 square miles in York, Pickens, Anderson, and Oconee Counties in South Carolina. The nominal pulse spacing for this...

  10. Scaling of the conductance distribution near the Anderson transition

    OpenAIRE

    Slevin, Keith; Markoš, Peter; Ohtsuki, Tomi

    2002-01-01

    The single parameter scaling hypothesis is the foundation of our understanding of the Anderson transition. However, the conductance of a disordered system is a fluctuating quantity which does not obey a one parameter scaling law. It is essential to investigate the scaling of the full conductance distribution to establish the scaling hypothesis. We present a clear cut numerical demonstration that the conductance distribution indeed obeys one parameter scaling near the Anderson transition.

  11. Finite Size Scaling Analysis of the Anderson Transition

    OpenAIRE

    Kramer, Bernhard; MacKinnon, Angus; Ohtsuki, Tomi; Slevin, Keith

    2010-01-01

    This chapter describes the progress made during the past three decades in the finite size scaling analysis of the critical phenomena of the Anderson transition. The scaling theory of localisation and the Anderson model of localisation are briefly sketched. The finite size scaling method is described. Recent results for the critical exponents of the different symmetry classes are summarised. The importance of corrections to scaling are emphasised. A comparison with experiment is made, and a di...

  12. The Anderson transition: time reversal symmetry and universality

    OpenAIRE

    Slevin, Keith; Ohtsuki, Tomi

    1997-01-01

    We report a finite size scaling study of the Anderson transition. Different scaling functions and different values for the critical exponent have been found, consistent with the existence of the orthogonal and unitary universality classes which occur in the field theory description of the transition. The critical conductance distribution at the Anderson transition has also been investigated and different distributions for the orthogonal and unitary classes obtained.

  13. Controlling Anderson localization in disordered photonic crystal waveguides

    DEFF Research Database (Denmark)

    Smolka, Stephan; Garcia, Pedro D.; Lodahl, Peter

    2010-01-01

    We prove Anderson localization in the slow-light regime of a photonic crystal waveguide by measuring the ensemble-averaged localization length which is controlled by the dispersion of the disordered photonic crystal waveguide.......We prove Anderson localization in the slow-light regime of a photonic crystal waveguide by measuring the ensemble-averaged localization length which is controlled by the dispersion of the disordered photonic crystal waveguide....

  14. Ferromagnetic order in the one-dimensional Anderson lattice

    International Nuclear Information System (INIS)

    Using bosonization an effective Hamiltonian is derived for the one-dimensional Anderson lattice model in the Toulouse limit. The effective Hamiltonian exhibits ferromagnetic ground state in the intermediate coupling regime. - Highlights: • 1D Anderson lattice is bosonized in the Toulouse limit. • The obtained effective Hamiltonian exhibits ferromagnetic order. • Ferromagnetism is due to a double-exchange mechanism. • The ferromagnetic transition has been identified to be an order–disorder transition

  15. Transverse Anderson localization of light: a tutorial review

    OpenAIRE

    Mafi, Arash

    2015-01-01

    This tutorial review gives an overview of the transverse Anderson localization of light in one and two transverse dimensions. A pedagogical approach is followed throughout the presentation, where many aspects of localization are illustrated by means of a few simple models. The tutorial starts with some basic aspects of random matrix theory, and light propagation through and reflection from a random stack of dielectric slabs. Transverse Anderson localization of light in one- and two-dimensiona...

  16. Modernization of meson channels of the JINR LNP Phasotron

    International Nuclear Information System (INIS)

    At the JINR LNP Phasotron, modernization of beamline T and meson beam channels 1, 2 and 3, for expansion of realization opportunities of physical researches on meson beams, was carried out. Parameters of existing beams were improved and new ones were generated. As a result of the modernization due to optimization of angles of secondary particle selection from targets and installation of additional lenses and magnets, the intensity of positive π meson beams on channel 3 has grown 3-40 times in the energy range 100-400 MeV and has run up to 3·107 s-1 per 1 μA intensity of the extracted proton beam. The maximum intensity of the π- meson beam in this range has reached 5·106 s-1 per 1 μA intensity of the extracted beam. On channels 1, 2 and 3 due to creation of stationary vacuum from the chamber of the phasotron with a branching on all beamlines of the mesons up to their end and accommodation in vacuum of two target stations, production of meson beams with momentum < 50 MeV/c, including surface muons with energy near 4 MeV, was made possible. Occurrence of conditions for formation of a narrow (focused on the meson targets in a horizontal plane up to 2-3 mm) proton beam allowed one to reduce 2-3 times the impurity of electronic or positronic components in all meson beams, and for beams of slow π mesons on channel 3 (10-40 MeV) the admixture of electron-positron components reduced 10-15 times due to increase of the angle of selection of π mesons up to 110 deg on the second target station. It became possible to apply small (∼ 80 mm) target from heavy elements for which the π-meson yield with a moment of about 100 MeV/c increased 2-4.5 times in comparison with a beryllium target of the identical size. (author)

  17. The completeness problem in the impurity Anderson model

    International Nuclear Information System (INIS)

    With the recent development of the nanoscopic technology, the impurity Anderson model (AIM) was experimentally realized in quantum dot devices, and there is renewed interest in the study of the Kondo physics of the AIM. Several Green's functions approximations by the equation of motion method (EOM), that incorporates the Kondo effect through a digamma function, have been presented in the literature as an adequate tool to describe, at least qualitatively, the Kondo effect. However, these approximations present several drawbacks: they are no longer valid as the temperature decreases below the Kondo temperature, because the logarithmic divergence of the digamma function makes the spectral density at the chemical potential to vanish, and the Friedel sum rule and the completeness in the occupation numbers are not fulfilled. In this work we present a critical discussion comparing the results of digamma approximations GF with the atomic approach, recently developed by some of us, that satisfy the completeness and the Friedel sum rule. We present results for the density of states, the Friedel sum rule and the completeness

  18. Spin susceptibility of Anderson impurities in arbitrary conduction bands

    Science.gov (United States)

    Fang, Tie-Feng; Tong, Ning-Hua; Cao, Zhan; Sun, Qing-Feng; Luo, Hong-Gang

    2015-10-01

    Spin susceptibility of Anderson impurities is a key quantity in understanding the physics of Kondo screening. Traditional numerical renormalization group (NRG) calculation of the impurity contribution χimp to susceptibility, defined originally by Wilson in a flat wide band, has been generalized before to structured conduction bands. The results brought about non-Fermi-liquid and diamagnetic Kondo behaviors in χimp, even when the bands are not gapped at the Fermi energy. Here, we use the full density-matrix (FDM) NRG to present high-quality data for the local susceptibility χloc and to compare them with χimp obtained by the traditional NRG. Our results indicate that those exotic behaviors observed in χimp are unphysical. Instead, the low-energy excitations of the impurity in arbitrary bands only without gap at the Fermi energy are still a Fermi liquid and paramagnetic. We also demonstrate that unlike the traditional NRG yielding χloc less accurate than χimp, the FDM method allows a high-precision dynamical calculation of χloc at much reduced computational cost, with an accuracy at least one order higher than χimp. Moreover, artifacts in the FDM algorithm to χimp and origins of the spurious non-Fermi-liquid and diamagnetic features are clarified. Our work provides an efficient high-precision algorithm to calculate the spin susceptibility of impurity for arbitrary structured bands, while negating the applicability of Wilson's definition to such cases.

  19. Meson Spectroscopy at COMPASS

    CERN Document Server

    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...

  20. Meson Spectroscopy at COMPASS

    CERN Document Server

    ,

    2016-01-01

    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...

  1. Leptonic Decays of Charged Pseudoscalar Mesons - 2015

    CERN Document Server

    Rosner, Jonathan L; Van de Water, Ruth S

    2015-01-01

    We review the physics of purely leptonic decays of $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of the constituent quarks and a strong interaction parameter related to the overlap of the quark and antiquark wave-functions in the meson, called the decay constant $f_P$. The leptonic decay constants for $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ mesons can be obtained with controlled theoretical uncertainties and high precision from {\\it ab initio} lattice-QCD simulations. The combination of experimental leptonic decay-rate measurements and theoretical decay-constant calculations enables the determination of several elements of the CKM matrix within the standard model. These determinations are competitive with those obtained from semileptonic decays, and also complementary because they are sensitive to different quark flavor-changing currents. They can also be use...

  2. Eta'-meson as pseudoscalar gluonium

    International Nuclear Information System (INIS)

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

  3. Investigation of Anderson lattice behavior in Yb1-xLuxAl3

    International Nuclear Information System (INIS)

    Measurements of magnetic susceptibility χ(T), specific heat C(T), Hall coefficient RH(T), and Yb valence ν = 2 + nf [f-occupation number nf (T) determined from Yb L3 x-ray absorption measurements] were carried out on single crystals of Yb1-xLuxAl3. The low temperature anomalies observed in χ(T) and C(T) corresponding to an energy scale Tcoh ∼ 40 K in the intermediate valence, Kondo lattice compound YbAl3 are suppressed by Lu concentrations as small as 5% suggesting these low-T anomalies are extremely sensitive to disorder and, therefore, are a true coherence effect. By comparing the temperature dependence of various physical quantities to the predictions of the Anderson Impurity Model, the slow crossover behavior observed in YbAl3, in which the data evolve from a low-temperature coherent, Fermi-liquid regime to a high temperature local moment regime more gradually than predicted by the Anderson Impurity Model, appears to evolve to fast crossover behavior at x ∼ 0.7 where the evolution is more rapid than predicted. These two phenomena found in Yb1-xLuxAl3, i.e., the low-T anomalies and the slow/fast crossover behavior are discussed in relation to recent theories of the Anderson lattice

  4. Topological approximation of the nonlinear Anderson model

    Science.gov (United States)

    Milovanov, Alexander V.; Iomin, Alexander

    2014-06-01

    We study the phenomena of Anderson localization in the presence of nonlinear interaction on a lattice. A class of nonlinear Schrödinger models with arbitrary power nonlinearity is analyzed. We conceive the various regimes of behavior, depending on the topology of resonance overlap in phase space, ranging from a fully developed chaos involving Lévy flights to pseudochaotic dynamics at the onset of delocalization. It is demonstrated that the quadratic nonlinearity plays a dynamically very distinguished role in that it is the only type of power nonlinearity permitting an abrupt localization-delocalization transition with unlimited spreading already at the delocalization border. We describe this localization-delocalization transition as a percolation transition on the infinite Cayley tree (Bethe lattice). It is found in the vicinity of the criticality that the spreading of the wave field is subdiffusive in the limit t →+∞. The second moment of the associated probability distribution grows with time as a power law ∝ tα, with the exponent α =1/3 exactly. Also we find for superquadratic nonlinearity that the analog pseudochaotic regime at the edge of chaos is self-controlling in that it has feedback on the topology of the structure on which the transport processes concentrate. Then the system automatically (without tuning of parameters) develops its percolation point. We classify this type of behavior in terms of self-organized criticality dynamics in Hilbert space. For subquadratic nonlinearities, the behavior is shown to be sensitive to the details of definition of the nonlinear term. A transport model is proposed based on modified nonlinearity, using the idea of "stripes" propagating the wave process to large distances. Theoretical investigations, presented here, are the basis for consistency analysis of the different localization-delocalization patterns in systems with many coupled degrees of freedom in association with the asymptotic properties of the

  5. Rotating strings confronting PDG mesons

    OpenAIRE

    Jacob Sonnenschein; Dorin Weissman

    2014-01-01

    We revisit the model of mesons as rotating strings with massive endpoints and confront it with meson spectra. We look at Regge trajectories both in the ( J, M 2 ) and ( n, M 2 ) planes, where J and n are the angular momentum and radial excitation number respectively. We start from states comprised of u and d quarks alone, move on to trajectories involving s and c quarks, and finally analyze the trajectories of the heaviest observed b b ¯ $$ b\\overline{b} $$ mesons. The endpoint masses provide...

  6. Heavy meson spectroscopy

    International Nuclear Information System (INIS)

    In this article we give a review of certain aspects of the present understanding of spectroscopy of heavy mesons and constituent quark masses in the light of non-relativistic potential model approach motivated by quantum chromodynamics. We find that the one gluon exchange at short distance and colour-confining interaction at large distance which is pure scalar (or scalar-vector admixture with dominant scalar interaction) under the Lorentz transformation, can explain only partially the present data on 1P states of cc-bar and bb-bar states. The S-wave data, that are available at present, however can be understood with both scalar confinement or scalar-vector admixture with scalar-dominant interaction. (author). 44 refs, 13 tabs

  7. Vector mesons in matter

    Indian Academy of Sciences (India)

    Gy Wolf

    2006-04-01

    One consequence of the chiral restoration is the mixing of parity partners. We look for a possible signature of the mixing of vector and axial vector mesons in heavy-ion collisions. We suggest an experimental method for its observation. The dynamical evolution of the heavy-ion collision is described by a transport equation of QMD-type evolving nucleons, * and resonances, ’s and $\\sum$ baryons, and furthermore, ’s, ’s ’s ’s ’s and kaons with their isospin degrees of freedom. The input cross-sections and resonance parameters of the model are fitted to the available nucleon–nucleon and pion–nucleon cross-sections.

  8. Meson spectroscopy with unitary coupled-channels model for heavy-meson decay into three mesons

    OpenAIRE

    Nakamura, Satoshi X.

    2012-01-01

    We develop a model for describing excited mesons decay into three mesons. The properties of the excited mesons can be extracted with this model. The model maintains the three-body unitarity that has been missed in previous data analyses based on the conventional isobar models. We study an importance of the three-body unitarity in extracting hadron properties from data. For this purpose, we use the unitary and isobar models to analyze the same pseudo data of gamma p -> pi+pi+pi-n, and extract ...

  9. An introduction to heavy mesons

    CERN Document Server

    Grinstein, B

    1995-01-01

    Introductory lectures (delivered at the VI Mexican School of Particles and Fields) on heavy quarks and heavy quark effective field theory. Applications to inclusive semileptonic decays and to interactions with light mesons are covered in detail.

  10. Neutral meson oscillations on the lattice

    CERN Document Server

    Carrasco, Nuria

    2014-01-01

    Accurate measurements of K, D and B meson mixing amplitudes provide stringent constraints in the Unitary Triangle analysis, as well as useful bounds on New Physics scales. Lattice QCD provides a non perturbative tool to compute the hadronic matrix elements entering in the effective weak Hamiltonian, with errors at a few percent level and systematic uncertainties under control. I review recent lattice results for these hadronic matrix element performed with $N_f=2$, $N_f=2+1$ and $N_f=2+1+1$ dynamical sea quarks.

  11. Argus-Fest. 20 years of B meson mixing 1987-2007. Proceedings

    International Nuclear Information System (INIS)

    The following topics were dealt with: ARGUS data, launching DORIS and ARGUS, B physics, discovery of B mixing, sociology of the ARGUS collaboration, CLEO B physics, from ARGUS to B-meson factories, the B factory era, B physics at the Tevatron, future of B physics programs, future of flavour physics. (HSI)

  12. Argus-Fest. 20 years of B meson mixing 1987-2007. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Lehner, F.; Faverot-Spengler, S. (eds.)

    2007-11-15

    The following topics were dealt with: ARGUS data, launching DORIS and ARGUS, B physics, discovery of B mixing, sociology of the ARGUS collaboration, CLEO B physics, from ARGUS to B-meson factories, the B factory era, B physics at the Tevatron, future of B physics programs, future of flavour physics. (HSI)

  13. Yukawa Meson, Sakata Model and Baryon-Lepton Symmetry Revisited

    Science.gov (United States)

    Marshak, R. E.

    It is difficult for me to grasp that this symposium is celebrating the jubilee of meson theory since I was a junior at Columbia College in 1935. I recall hearing a colloquium by Paul Dirac that year telling an enraptured audience about the infinite sea of negative energy states but I do not recall any special note being taken of the birth of an equally revolutionary concept, the Yukawa meson. Perhaps the reason was the publication of Hideki Yukawa's paper in an inaccessible Japanese journal, perhaps Dirac's electron theory was dealing with the well-known electromagnetic force whereas Yukawa' meson theory was put forth to understand the nature of two new forces - the nuclear and the weak. Whatever the reason, the situation changed drastically when I migrated to Cornell (to do my thesis under Hans Bethe during the years 1937sim39) and found a deep interest in meson theory. Thus, my own scientific career has almost spanned the period since the birth of meson theory but, what is more to the point, it has been strongly influenced by the work of Yukawa and his collaborators. It therefore gives me great pleasure to be able to talk at this MESON 50 symposium. As one of the oldest speakers, I shall respond in a loose way to Professor Maki's invitation to cover ``topics concerning the historical developments of hadron physics''. I shall select several major themes from the Japanese work that have had special interest for me. My remarks will fall under the four headings: (A) Yukawa Meson; (B) Sakata Model; (C) Baryon-Lepton Symmetry; and (D) Extensions of Baryon-Lepton Symmetry.

  14. Investigation of Semileptonic B Meson Decays to p -Wave Charm Mesons

    International Nuclear Information System (INIS)

    We have studied semileptonic B meson decays with a p -wave charm meson in the final state using 3.29x106 BB events collected with the CLEOII detector at the Cornell Electron-Positron Storage Ring. We find a value for the exclusive semileptonic product branching fraction B(B-→D01 ell -νell) B(D01→D*+ π-)=(0.373±0.085± 0.052±0.024)% and an upper limit for B(B-→D*02 ell -νell) B(D*02→D*+ π-)2 spectrum for B-→D01 ell - νell . copyright 1998 The American Physical Society

  15. Meson Structure in a Relativistic Many-Body Approach

    International Nuclear Information System (INIS)

    Results from an extensive relativistic many-body analysis utilizing a realistic effective QCD Hamiltonian are presented for the meson spectrum. A comparative numerical study of the BCS, Tamm-Dancoff (TDA), and RPA treatments provides new, significant insight into the condensate structure of the vacuum, the chiral symmetry governance of the pion, and the meson spin, orbital, and flavor mass splitting contributions. In contrast to a previous glueball application, substantial quantitative differences are computed between TDA and RPA for the light quark sector with the pion emerging as a Goldstone boson only in the RPA. (c) 2000 The American Physical Society

  16. D meson hadronic decays at CLEO-c

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Fan; /Fermilab

    2011-01-01

    The recent CLEO-c results on hadronic decays of D and D{sub s} mesons are presented. First the absolute branching fractions for D and D{sub s} mesons using a double tag technique are discussed, then are the Cabibbo suppressed decays and doubly Cabibbo suppressed decays. Finally, I present the inclusive and rare decay modes and other measurements from CLEO-c. These decays illuminate a wide range of physics. A brief theoretical introduction is given before the corresponding discussion on measurement.

  17. Hybrid Meson Potentials and the Gluonic van der Waals Force

    CERN Document Server

    Lakhina, O

    2004-01-01

    The chromoelectric polarizability of mesons governs the strength of the gluonic van der Waals force and therefore of non-quark-exchange processes in hadronic physics. We compute the polarizability of heavy mesons with the aid of lattice gauge theory and the Born--Oppenheimer adiabatic expansion. We find that the operator product expansion breaks down at surprisingly large quarks masses due to nonperturbative gluodynamics and that previous conclusions concerning $J/\\psi$--nuclear matter interactions and $J/\\psi$ dissociation in the quark-gluon plasma must be substantially modified.

  18. Bianchi Type-I cosmological mesonic stiff fluid models in Lyra's geometry

    Indian Academy of Sciences (India)

    S D Katore; S V Thakare; K S Adhao

    2008-07-01

    Bianchi Type-I cosmological models in Lyra's geometry are obtained when the source of gravitational field is a perfect fluid coupled with massless mesonic scalar field. Some physical and kinematical properties of the models are also discussed.

  19. Hadronic Physics

    OpenAIRE

    Mahlke, Hanna

    2000-01-01

    I review the novel results and developments presented at the Third Workshop on Physics and Detectors for DA$\\Phi$NE that deal with hadronic physics. Topics discussed include: the scalar quark condensate, kaon decays, the sector of scalar and vector mesons, kaon-nucleon scattering, pion- and kaon-nucleon sigma terms, and strange nuclear physics.

  20. The Anderson-Darling test of fit for the power law distribution from left censored samples

    CERN Document Server

    Coronel-Brizio, H F

    2010-01-01

    Maximum likelihood estimation and a test of fit based on the Anderson-Darling statistic is presented for the case of the power law distribution when the parameters are estimated from a left-censored sample. Expressions for the maximum likelihood estimators and tables of asymptotic percentage points for the A^2 statistic are given. The technique is illustrated for data from the Dow Jones Industrial Average index, an example of high theoretical and practical importance in Econophysics, Finance, Physics, Biology and, in general, in other related Sciences such as Complexity Sciences.

  1. Weak Anderson localisation in reverberation rooms and its effect on the uncertainty of sound power measurements

    DEFF Research Database (Denmark)

    Jacobsen, Finn

    2011-01-01

    The effect known as ‘weak Anderson localisation’, ‘coherent backscattering’ or ‘enhanced backscattering’ is a physical phenomenon that occurs in random systems, e.g., disordered media and linear wave systems, including reverberation rooms: the mean square response is increased at the drive point....... In a reverberation room this means that one can expect an increase of the reverberant sound field at the position of the source that generates the sound field. This affects the sound power output of the source and is therefore of practical concern. However, because of the stronger direct sound field...... implications for the uncertainty of sound power measurements....

  2. An Anderson-like model of the QCD chiral transition

    CERN Document Server

    Giordano, Matteo; Pittler, Ferenc

    2016-01-01

    We study the problems of chiral symmetry breaking and eigenmode localisation in finite-temperature QCD by looking at the lattice Dirac operator as a random Hamiltonian. We recast the staggered Dirac operator into an unconventional three-dimensional Anderson Hamiltonian ("Dirac-Anderson Hamiltonian") carrying internal degrees of freedom, with disorder provided by the fluctuations of the gauge links. In this framework, we identify the features relevant to chiral symmetry restoration and localisation of the low-lying Dirac eigenmodes in the ordering of the local Polyakov lines, and in the related correlation between spatial links across time slices, thus tying the two phenomena to the deconfinement transition. We then build a toy model based on QCD and on the Dirac-Anderson approach, replacing the Polyakov lines with spin variables and simplifying the dynamics of the spatial gauge links, but preserving the above-mentioned relevant dynamical features. Our toy model successfully reproduces the main features of the...

  3. Rapidity resummation for B-meson wave functions

    Directory of Open Access Journals (Sweden)

    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.

  4. Current status of high energy nucleon-meson transport code

    Energy Technology Data Exchange (ETDEWEB)

    Takada, Hiroshi; Sasa, Toshinobu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Current status of design code of accelerator (NMTC/JAERI code), outline of physical model and evaluation of accuracy of code were reported. To evaluate the nuclear performance of accelerator and strong spallation neutron origin, the nuclear reaction between high energy proton and target nuclide and behaviors of various produced particles are necessary. The nuclear design of spallation neutron system used a calculation code system connected the high energy nucleon{center_dot}meson transport code and the neutron{center_dot}photon transport code. NMTC/JAERI is described by the particle evaporation process under consideration of competition reaction of intranuclear cascade and fission process. Particle transport calculation was carried out for proton, neutron, {pi}- and {mu}-meson. To verify and improve accuracy of high energy nucleon-meson transport code, data of spallation and spallation neutron fragment by the integral experiment were collected. (S.Y.)

  5. High statistics inclusive phi-meson production at SPS energies

    International Nuclear Information System (INIS)

    This thesis describes an experiment studying the inclusive reaction hadron + Be → phi + anything → K+ + K- + anything in 100 GeV/c, 120 GeV/c and 200 GeV/c hadron interactions. A total of 8x106 events were recorded using both positively and negatively charged unseparated hadron beams supplied by the CERN SPS. The experiment made use of an intelligent on-line event selection system based on micro-processors (FAMPs) in conjunction with a system of large MWPCs to increase the number of phi-events recorded per unit time. In 32 days of data taking over 600,000 phi-mesons were recorded onto magnetic tape. The physics motivation for collecting a large statistics sample of inclusive phi-mesons was the investigation of the inclusive phi-meson production mechanism and phi-spectroscopy. (Auth.)

  6. Effects of isovector scalar $\\delta$-meson on hypernuclei

    CERN Document Server

    Ikram, M; Biswal, S K; Patra, S K

    2014-01-01

    We analyze the effects of $\\delta-$ meson on hypernuclei within the frame-work of relativistic mean field theory. The $\\delta-$ meson is included into the Lagrangian for hypernuclei. The extra nucleon-meson coupling ($g_\\delta$) affects the every piece of physical observables, like binding energy, radii and single particle energy of hypernuclei. The lambda mean field potential is investigated which is consistent with other predictions. Flipping of single particle energy levels are observed with the strength of $g_\\delta$ in the considered hypernuclei as well as normal nuclei. The spin-orbit potentials are observed for considered hypernuclei and the effect of $g_\\delta$ on spin-orbit potentials is also analyzed. The calculated single-$\\Lambda$ binding energies ($B_\\Lambda$) are quite agreeable with the experimental data.

  7. Regarding the enigmas of P-wave meson spectroscopy

    International Nuclear Information System (INIS)

    The mass spectrum of P-wave mesons is considered in a nonrelativistic constituent quark model. The results show the common mass degeneracy of the isovector and isodoublet states of the scalar and tensor meson nonets, m(a0)congruent m(a2), m(K0*)congruent m(K2*), and do not exclude the possibility of a similar degeneracy of the same states of the axial-vector and pseudovector nonets. Current experimental hadronic and τ-decay data suggest, however, a different scenario leading to the a1 meson mass ≅1190 MeV and the K1A-K1B mixing angle ≅(37±3)degree. Possible s bar s states of the four nonets are also discussed. copyright 1998 The American Physical Society

  8. Semileptonic Decays of Pseudoscalar Mesons: A New Approach

    CERN Document Server

    Chia, Swee Ping

    2013-01-01

    Because quarks in hadronic states are subjected to strong QCD forces, it is not straight-forward to apply calculation obtained at the quark level to physical processes involving hadrons. In this paper we present a new approach to treat the semileptonic decays of pseudoscalar mesons. At the quark level, the process is straightforward. However, when we fold the quark-level process to the meson decay process, the complication from QCD effects come in. We make the fundamental assumption that the vertex of type M-q-qbar can be approximated by an effective constant gamma-5 coupling. With this assumption, the hadronic process can then be related to the quark-level process. The model is applied to the semileptonic decays of pi, K, D and B mesons.

  9. Conductance fluctuations in a macroscopic 3-dimensional Anderson insulator

    International Nuclear Information System (INIS)

    We report magnetoconductance experiment on a amorphous Yx-Si1-x alloy (∼0.3). which is an Anderson insulator where spin-orbit scattering is strong. Two principal and new features emerge from the data: the first one is an halving of the localization length by the application of a magnetic field of about 2.5 Teslas. This effect is predicted by a new approach of transport in Anderson insulators where basic symetry considerations are the most important ingredient. The second one is the observation of reproducible conductance fluctuations at very low temperature in this macroscopic 3 D amorphous material

  10. Multiple-beam Propagation in an Anderson Localized Optical Fiber

    CERN Document Server

    Karbasi, Salman; Mafi, Arash

    2012-01-01

    We investigate the simultaneous propagation of multiple beams in a disordered Anderson localized optical fiber. The profiles of each beam fall off exponentially, enabling multiple channels at high-density. We examine the influence of fiber bends on the movement of the beam positions, which we refer to as drift. We investigate the extent of the drift of localized beams induced by macro-bending and show that it is possible to design Anderson localized optical fibers which can be used for practical beam-multiplexing applications.

  11. Absence of Anderson localization in certain random lattices

    OpenAIRE

    Choi, Wonjun; Yin, Cheng; Hooper, Ian R.; Bernes, William L.; Bertolotti, Jacopo

    2016-01-01

    We report on the transition between an Anderson localized regime and a conductive regime in a 1D scattering system with correlated disorder. We show experimentally that when long-range correlations, in the form of a power-law spectral density with power larger than 2, are introduced the localization length becomes much bigger than the sample size and the transmission peaks typical of an Anderson localized system merge into a pass band. As other forms of long-range correlations are known to ha...

  12. Controlling Anderson localization in disordered photonic crystal waveguides

    DEFF Research Database (Denmark)

    Garcia-Fernández, David; Smolka, Stephan; Stobbe, Søren; Lodahl, Peter

    Quantum optics and quantum information technologies require enhancement of light-matter interaction by, for example, confining light in a small volume. A very recently demonstrated route towards light confinement makes use of multiple scattering of light and wave interference in disordered photonic...... structures [1,2]. Originally proposed for electrons by P. W. Anderson [3], only completely random systems without any long-range correlation between the scattering sites have been used so far, meaning that the Anderson-localized modes cannot be controlled. In disordered photonic crystals, these modes are...

  13. A Constituent Quark-Meson Model for Heavy Meson Decays

    CERN Document Server

    Deandrea, Aldo

    1998-01-01

    I describe a model for heavy meson decays based on an effective quark-meson lagrangian. I consider the heavy mesons S with spin and parity J^P=(1+,0+), H with J^P=(1-,0-) and T^mu with J^P=(2+,1+), i.e. S and P wave heavy-light mesons. The model is constrained by the known symmetries of QCD in the mQ -> infinity limit for the heavy quarks, and chiral symmetry in the light quark sector. Using a very limited number of free parameters it is possible to compute several phenomenological quantities, e.g. the leptonic B and B** decay constants; the three universal Isgur-Wise form factors: xi, tau(3/2), tau(1/2), describing the semi-leptonic decays B -> D(*) l nu, B -> D** l nu; the strong and radiative D* decays; the weak semi-leptonic decays of B and D into light mesons: pi, rho, a1. An overall agreement with data, when available, is achieved.

  14. Cross sections for meson-meson nonresonant reactions

    CERN Document Server

    Li, Yu-Qi

    2007-01-01

    Meson-meson nonresonant reactions governed by the quark-interchange mechanism are studied in a potential that is derived from QCD. S-wave elastic phase shifts for I=2 \\pi\\pi and I=3/2 K \\pi scattering are obtained with wave functions determined by the central spin-independent term of the potential. The reactions include inelastic scatterings of two mesons in the ground-state pseudoscalar octet and the ground-state vector nonet. Cross sections for reactions involving pion, rho, K and K^* indicate that mesonic interactions in matter consisting of only K and K^* can be stronger than mesonic interactions in matter consisting of only pions and rhos and the reaction of I=3/2 \\pi K^* \\to \\rho K is most important among the endothermic nonresonant reactions. By the quark-interchange mechanism we can offer \\sqrt s-dependences of phi absorption cross sections in collisions with pion and rho and relevant average cross sections what are very small for the reaction of I=1 \\pi \\phi \\to K^* K^* and remarkably large for the r...

  15. Inverse meson mass ordering in the color-flavor-locking phase of high-density QCD

    International Nuclear Information System (INIS)

    We derive the effective Lagrangian for the low-energy massive meson excitations of the color-flavor-locking (CFL) phase of QCD with three flavors of light quarks. We compute the decay constants, the maximum velocities, and the masses of the mesons at large baryon chemical potential μ. The decay constants are linear in μ. The meson maximum velocities are close to that of sound. The meson masses in the CFL phase are significantly smaller than in the normal QCD vacuum and depend only on bare quark masses. The order of the meson masses is, to some extent, reversed compared to that in the QCD vacuum. In particular, the lightest particle is η'. (c) 2000 The American Physical Society

  16. Experimental study of charm at LEP by the D* meson channel with ALEPH detector

    International Nuclear Information System (INIS)

    This research deals with the analysis of some 500 000 neutral Z bosons recorded with the ALEPH detector between 1989 and 1991. The physical subject concerns the study of charm at LEP and more precisely the production of charmed mesons, charged and excited: D*. Charged mesons are reconstructed in the channel with two pions and one kaon in the final state via the decay of neutral charmed one. We have measured simultaneously the ratio of D* meson production, the relative contribution of charm and beauty in D* meson production and the average fraction of the beam energy carried away by the D* meson at the time of its fragmentation. The charge asymmetry of charm has been also measured thanks to the high purity in charm events obtained by the D* tagging and finally allows us to infer the value of the electroweak mixing angle

  17. Average neutron energy measurement at an accelerator facility, a practical health physics problem

    International Nuclear Information System (INIS)

    Surveys designed to estimate the average energy of neutrons escaping from shielded enclosures were made at the Clinton P. Anderson Meson Physics Facility (LAMPF). Information obtained from these data proved to be of value in establishing response factors for the personnel monitoring dosimeters (NTA film). The value of measuring average neutron energies was demonstrated about one year ago, when the monthly film badge report indicated significant neutron exposures to personnel of an experimental group at LAMPF. Neutron radiation-survey data, as well as recorded data from area monitoring stations, indicated much lower personnel neutron doses. Subsequent average neutron energy measurements, at the location of interest, revealed a well-defined region where average neutron energies were considerably greater than previously measured in other occupied areas of the accelerator facility. A discussion is given the rationale for the decision to alter for these experimenters the NTA film response factors from that normally applied to the LAMPF film badges

  18. Analysis of Anderson Acceleration on a Simplified Neutronics/Thermal Hydraulics System

    Energy Technology Data Exchange (ETDEWEB)

    Toth, Alex [North Carolina State University (NCSU), Raleigh; Kelley, C. T. [North Carolina State University (NCSU), Raleigh; Slattery, Stuart R [ORNL; Hamilton, Steven P [ORNL; Clarno, Kevin T [ORNL; Pawlowski, R. P. P. [Sandia National Laboratories (SNL)

    2015-01-01

    ABSTRACT A standard method for solving coupled multiphysics problems in light water reactors is Picard iteration, which sequentially alternates between solving single physics applications. This solution approach is appealing due to simplicity of implementation and the ability to leverage existing software packages to accurately solve single physics applications. However, there are several drawbacks in the convergence behavior of this method; namely slow convergence and the necessity of heuristically chosen damping factors to achieve convergence in many cases. Anderson acceleration is a method that has been seen to be more robust and fast converging than Picard iteration for many problems, without significantly higher cost per iteration or complexity of implementation, though its effectiveness in the context of multiphysics coupling is not well explored. In this work, we develop a one-dimensional model simulating the coupling between the neutron distribution and fuel and coolant properties in a single fuel pin. We show that this model generally captures the convergence issues noted in Picard iterations which couple high-fidelity physics codes. We then use this model to gauge potential improvements with regard to rate of convergence and robustness from utilizing Anderson acceleration as an alternative to Picard iteration.

  19. Proceedings of the Kyoto international symposium : the jubilee of the meson theory

    International Nuclear Information System (INIS)

    Kyoto international symposium: The Jubilee of the Meson Theory was held at Kyoto International Conference Hall from August 15 to 17, 1985, under the auspices of the Research Institute for Fundamental Physics, the Faculty of Science and the College of Liberal Arts of Kyoto University, in cooperation with many organizations concerned. Meson theory was proposed by Hideki Yukawa in 1935, only a decade after the birth of quantum mechanics. At that time, much confusion prevailed about the applicability of quantum theory. Yukawa's meson theory indicated the right direction for developing particle physics, and established that quantum field theory is the correct theory even inside a nucleus. Thus it may be said that particle physics began with Yukawa's meson theory. The purpose of this symposium was to celebrate the 50th anniversary of Yukawa's meson theory, to review the development of particle physics during these 50 years and the application of meson physics to various fields, and to discuss current topics in particle physics in order to obtain some insight into its future progress in the fundamental theory of space-time and matter. 88 foreign physicists from 18 countries and 172 Japanese scientists participated, and 32 interesting talks were given. (Kako, I.)

  20. Meson Strings and Flavor Branes

    CERN Document Server

    Bando, M; Terunuma, S; Bando, Masako; Sugamoto, Akio; Terunuma, Sachiko

    2006-01-01

    In a QCD-like string model based on D6 flavor branes in the presence of D4 color branes wrapping one of the compactified dimension on an $S^1$, the shape of meson strings in the five dimensional curved space as well as the potential between quark and anti-quark are investigated. The flavor branes on which both ends of a meson string live are assumed to be separated in this five dimensional space, depending on the values of the constituent quark masses. It is shown in this picture that the meson string with different flavors on both ends changes its shape at a critical distance. There is, however, no critical distance for the meson with the same flavors. At this critical distance the potential between quark and anti-quark with different flavors gives a point of reflection and changes its shape around this point. Accordingly, the attractive force between quark and anti-quark seems to become stronger when the distance of flavor branes connecting meson strings becomes larger. This indicates quark systems with dif...

  1. Beauty Meson Decays To Charmonium

    CERN Document Server

    Ershov, A V

    2001-01-01

    We study decays of beauty (B) mesons into the final states containing charmonium mesons. The data were collected by the CLEO experiment at the Cornell Electron Storage Ring from 1990 to 1999. First, we describe a technique that significantly improves the reconstruction efficiency for decays of J/ y and y (2S) mesons into a pair of leptons. This reconstruction method is used in all the analyses presented in this dissertation. Then we present a study of B decays to the χc 1 and χc2 charmonium states and compare our results with the predictions of different theoretical models of charmonium production. After that we report the first observation of the decay B → J/ y &phis;K, which is the first B meson decay requiring a creation of an additional ss¯ quark pair. Then we measure the B0 and B+ meson masses from B0 → y (′) K0S and B+ → y (′) K+ decays. The method employed eliminates the dominant systematic uncertainty associated w...

  2. Quantum-classical correspondence in multimensional nonlinear systems: Anderson localization and "superdiffusive" solitons

    KAUST Repository

    Brambila, Danilo

    2012-01-01

    We have theoretically studied Anderson localization in a 2D+1 nonlinear kicked rotor model. The system shows a very rich dynamical behavior, where the Anderson localization is suppressed and soliton wave-particles undergo a superdiffusive motion.

  3. Search for rare B meson decays into Ds+ mesons

    International Nuclear Information System (INIS)

    A search has been performed for rare B meson decays into Ds+ mesons arising from b→u transitions, W exchange modes, B+ annihilation processes, and decays where the Ds+ 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 Ds+l- correlations an upper limit of BR(B→Ds+l-X)<1.2%(90% CL) is determined. (orig.)

  4. Vector meson-vector meson interaction and dynamically generated resonances

    International Nuclear Information System (INIS)

    We report upon 11 composite meson states, dynamically generated from the vector meson–vector meson interaction using the local hidden gauge formalism within a unitary approach. Six of these states are associated to the f0(1370), f0(1710), f2(1270), f'2(1525), a2(1320) and K*2(1430) resonances. At the same time we predict five other states with the quantum numbers of h1, a0, b1, K*0, and K1 which could be tested by future experiments.

  5. An Anderson-like model of the QCD chiral transition

    Science.gov (United States)

    Giordano, Matteo; Kovács, Tamás G.; Pittler, Ferenc

    2016-06-01

    We study the problems of chiral symmetry breaking and eigenmode localisation in finite-temperature QCD by looking at the lattice Dirac operator as a random Hamiltonian. We recast the staggered Dirac operator into an unconventional three-dimensional Anderson Hamiltonian ("Dirac-Anderson Hamiltonian") carrying internal degrees of freedom, with disorder provided by the fluctuations of the gauge links. In this framework, we identify the features relevant to chiral symmetry restoration and localisation of the low-lying Dirac eigenmodes in the ordering of the local Polyakov lines, and in the related correlation between spatial links across time slices, thus tying the two phenomena to the deconfinement transition. We then build a toy model based on QCD and on the Dirac-Anderson approach, replacing the Polyakov lines with spin variables and simplifying the dynamics of the spatial gauge links, but preserving the above-mentioned relevant dynamical features. Our toy model successfully reproduces the main features of the QCD spectrum and of the Dirac eigenmodes concerning chiral symmetry breaking and localisation, both in the ordered (deconfined) and disordered (confined) phases. Moreover, it allows us to study separately the roles played in the two phenomena by the diagonal and the off-diagonal terms of the Dirac-Anderson Hamiltonian. Our results support our expectation that chiral symmetry restoration and localisation of the low modes are closely related, and that both are triggered by the deconfinement transition.

  6. Anderson-Witting transport coefficients for flows in general relativity

    CERN Document Server

    Ambrus, Victor E

    2016-01-01

    The transport coefficients induced by the Anderson-Witting approximation of the collision term in the relativistic Boltzmann equation are derived for close to equilibrium flows in general relativity. Using the tetrad formalism, it is shown that the expression for these coefficients is the same as that obtained on flat space-time, in agreement with the generalized equivalence principle.

  7. Spectral density method to Anderson-Holstein model

    International Nuclear Information System (INIS)

    Two-parameter spectral density function of a magnetic impurity electron in a non-magnetic metal is calculated within the framework of the Anderson-Holstein model using the spectral density approximation method. The effect of electron-phonon interaction on the spectral function is investigated

  8. Magnetic susceptibility of a two-channel Anderson model

    International Nuclear Information System (INIS)

    Temperature-dependent magnetic susceptibility is calculated for a two-channel Anderson model, by using the numerical renormalization group plus an interleaving procedure to recover the continuum of the conduction band. Fermi- and non-Fermi-liquid fixed points can be obtained in the low-temperature regime of the model susceptibility

  9. Magnetic susceptibility of a two-channel Anderson model

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, J.V.B.; Oliveira, L.N. de; Cox, D.L.; Libero, V.L. E-mail: valter@if.sc.usp.br

    2001-05-01

    Temperature-dependent magnetic susceptibility is calculated for a two-channel Anderson model, by using the numerical renormalization group plus an interleaving procedure to recover the continuum of the conduction band. Fermi- and non-Fermi-liquid fixed points can be obtained in the low-temperature regime of the model susceptibility.

  10. Probing the statistical properties of Anderson localization with quantum emitters

    DEFF Research Database (Denmark)

    Smolka, Stephan; Nielsen, Henri Thyrrestrup; Sapienza, Luca;

    2011-01-01

    embedded in disordered photonic crystal waveguides as light sources. Anderson-localized modes are efficiently excited and the analysis of the photoluminescence spectra allows us to explore their statistical properties, for example the localization length and average loss length. With increasing the amount...

  11. Cavity quantum electrodynamics with Anderson-localized modes

    DEFF Research Database (Denmark)

    Sapienza, Luca; Nielsen, Henri Thyrrestrup; Stobbe, Søren;

    2010-01-01

    factor of 15 on resonance with the Anderson-localized mode, and 94% of the emitted single photons coupled to the mode. Disordered photonic media thus provide an efficient platform for quantum electrodynamics, offering an approach to inherently disorder-robust quantum information devices....

  12. Neutral B meson flavor tagging

    CERN Document Server

    Wilson, R J

    2001-01-01

    We present an investigation of the use of net charge and kaon identification to tag the flavor of neutral B mesons. The net charge of the neutral B meson decay products is zero if all charged particles are used and slightly non-zero if only undiscriminated hadronic final states are used. The net charge of the kaons alone correctly tags the identity of the neutral meson in at least a third of all decays. We have parametrized the particle identification capability of several techniques, such as dE/dx in time projection chambers, LEP/SLC ring-imaging chambers and an enhanced BaBar DIRC. Using these parametrisations we compare the relative tagging power of each technique to that of an ideal detector. (8 refs).

  13. Exclusive and inclusive weak decays of the B-meson

    Energy Technology Data Exchange (ETDEWEB)

    Grach, I.L.; Narodetskii, I.M.; Ter-Martirosyan, K.A. [Institute of Theor. and Exp. Phys., Moscow (Russian Federation); Simula, S. [Istituto Nazionale di Fisica Nucleare, Sezione Sanita, Viale Regina Elena 299, I-00161 Rome (Italy)

    1997-09-29

    A relativistic quark model is applied to the description of semileptonic and non-leptonic charmed decays of the B-meson. The exclusive semileptonic modes B{yields}Dl{nu}{sub l} and B{yields}D{sup *}l{nu}{sub l} are described through the universal Isgur-Wise form factor, which is calculated in terms of a constituent quark model wave function for the B-meson. Different approximations for the latter, either based on a phenomenological ansatz or derived from analyses of the meson spectra, are adopted. In particular, two wave functions, constructed via the Hamiltonian light-front formalism using a relativized and a non-relativistic constituent quark model, are considered, obtaining a link between standard spectroscopic quark models and the B-meson decay physics. The inclusive semileptonic and non-leptonic branching ratios are calculated within a convolution approach, inspired by the partonic model and involving the same B-meson wave function used for the evaluation of the exclusive semileptonic modes. Our results for the major branching ratios are consistent with available experimental data and the sum of all the calculated branchingratios turns out to be close to unity. In particular, we found that (i) a remarkable fraction ({proportional_to}35%) of semileptonic decay modes occur in non-D, non-D{sup *} final states; (ii) non-perturbative effects enhance the inclusive b{yields}c anti ud decay channels, with a sizable contribution provided by internal decays into heavy mesons and baryon-antibaryon pairs; the resulting reduction of the semileptonic branching ratio brings the theoretical prediction in agreement with the experimental value without increasing at the same time the charm counting. (orig.). 47 refs.

  14. Strange axial-vector mesons

    International Nuclear Information System (INIS)

    The strange axial-vector mesons K1 (1270) and K1 (1400) are reanalyzed in the light of the updated experimental information and compared with the recent result on the Kππ production in τ decay. The mixing angle between the strange mesons of 3P1 and 1P1 is determined by the partial decay rates, and, independently, by the masses. They lead to θK∼33 degree or 57 degree. The observed K1 (1400) production dominance in the τ decay favors θK∼33 degree. Flavor-SU(3) breaking of 20% or so in the production amplitudes can explain quantitatively the observed production ratio

  15. Beauty meson decays to charmonium

    Science.gov (United States)

    Ershov, Alexey Valerievich

    2001-10-01

    We study decays of beauty (B) mesons into the final states containing charmonium mesons. The data were collected by the CLEO experiment at the Cornell Electron Storage Ring from 1990 to 1999. First, we describe a technique that significantly improves the reconstruction efficiency for decays of J/ y and y (2S) mesons into a pair of leptons. This reconstruction method is used in all the analyses presented in this dissertation. Then we present a study of B decays to the χc 1 and χc2 charmonium states and compare our results with the predictions of different theoretical models of charmonium production. After that we report the first observation of the decay B --> J/ y φK, which is the first B meson decay requiring a creation of an additional ss¯ quark pair. Then we measure the B0 and B+ meson masses from B0 --> y (') K0S and B+ --> y (') K+ decays. The method employed eliminates the dominant systematic uncertainty associated with the previous B meson mass measurements at the e+e- colliders and results in a significant improvement in precision. After that we present a study of three B0 decay modes useful for time-dependent CP asymmetry measurements. In this study we reconstruct B0 --> J/ y K0S , B0 --> χc 1 K0S , and B0 --> J/ y π0 decays. The latter two decay modes are observed for the first time. We describe a K0S --> π0π0 detection technique and its application to the reconstruction of the decay B 0 --> J/ y K0S . Then we present a sensitivity study for the measurement of the mixing-induced CP violation in the neutral B meson system (parameter sin 2β) at CLEO using the method that requires a measurement of the decay time of only one meson in a B0overline B0 pair. Finally, we search for direct CP violation in decays B+/- --> J/ y K+/- and B +/- --> y (2S) K+/- . The results of this search are consistent with the Standard Model expectations and provide the first experimental test of the assumption that direct CP violation is negligible in B --> y (') K decays.

  16. Status of light scalar mesons as non-ordinary mesons

    International Nuclear Information System (INIS)

    In this talk I briefly review the status of the f0(500) and f0(980) together with the other light scalar resonances, as well as the emerging picture of a non-ordinary light meson multiplet, paying particular attention to unitarized Chiral Perturbation Theory, large Nc, semilocal duality and Regge theory arguments

  17. Search for Neutrinoless τ Decays Involving π0 or η Mesons

    International Nuclear Information System (INIS)

    We have searched for lepton flavor violating decays of the τ lepton using final states with an electron or a muon and one or two π0 or η mesons but no neutrinos. The data used in the search were collected with the CLEO II detector at the Cornell Electron Storage Ring (CESR) and correspond to an integrated luminosity of 4.68 fb-1 . No evidence for signals was found, resulting in much improved limits on the branching fractions for the one-meson modes and the first upper limits for the two-meson modes. copyright 1997 The American Physical Society

  18. Formalism and assumptions involved in partial-wave analysis of three- meson systems

    CERN Document Server

    Hansen, J D; Otter, Gerd; Rudolph, G

    1974-01-01

    The Illinois group has made partial-wave analysis of the reaction pi p to (3 pi )p. The authors have modified the Illinois program to study the reaction Kp to (K pi pi )p. A detailed description is given of the partial-wave analysis of any reaction of the kind: meson+proton to proton+(3 mesons). It is also shown that, with little modification, the method can be applied to the study of special four-meson systems like K omega . A discussion is given of the physical assumptions used and of their implications. (21 refs).

  19. Beautiful mesons from QCD spectral sum rules

    Energy Technology Data Exchange (ETDEWEB)

    Narison, S.

    1988-08-18

    We apply q/sup 2/ = 0 moments within n (number of derivatives) and t/sub c/ (continuum threshold) stability criteria to the beautiful-meson systems. The optimal predictions are reached for the same ranges of n and t/sub c/ values leading to the previous estimate of the decay constant f/sub B/. The QCD scales (b-quark 'physical' mass, mixed and four-quark condensates) are strongly constrained by the observed B and B/sup */ masses. The predictions for the S- and P-state splittings are much affected by the definition of the b-quark mass (pole or euclidian) entering into the Wilson coefficients of the non-perturbative condensates. The size of the SU(3)/sub F/ breaking on the mass splittings cannot be accurately predicted due to the imprecise value of the / condensate ratio. We present new predictions for the B/sub c/ and B/sub c//sup */ mesons.

  20. Unraveling the pattern of the $XYZ$ mesons

    CERN Document Server

    Vijande, J

    2015-01-01

    We present a plausible mechanism for the origin of the $XYZ$ mesons in the heavy meson spectra within a standard quark-model picture. We discuss the conditions required for the existence of four--quark bound states or resonances contributing to the heavy meson spectra, being either compact or molecular. We concentrate on charmonium and bottomonium spectra, where several new states, difficult to understand as simple quark-antiquark pairs, have been reported by different experimental collaborations. The pivotal role played by entangled meson-meson thresholds is emphasized.

  1. The meson spectroscopy program with CLAS12 at Jefferson Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, Alessandro [Univ. of Rome Tor Vergata (Italy)

    2016-06-01

    experimental hadronic physics all over the world, to investigate and propose new analysis models and new statistical techniques to unfold signal and background. The new analysis framework is being developed and tested using the existing CLAS data and results are projected to the CLAS12 performances, showing that the quest for hybrid exotic mesons is at reach.

  2. Holographic mesons in various dimensions

    CERN Document Server

    Myers, R C; Myers, Robert C.; Thomson, Rowan M.

    2006-01-01

    We calculate the spectrum of fluctuations of a probe Dk-brane in the background of N Dp-branes, for k=p,p+2,p+4 and p< 5. The result corresponds to the mesonic spectrum of a (p+1)-dimensional super-Yang-Mills (SYM) theory coupled to `dynamical quarks', i.e., fields in the fundamental representation -- the latter are confined to a defect for k=p and p+2. We find a universal behaviour where the spectrum is discrete and the mesons are deeply bound. The mass gap and spectrum are set by the scale M ~ m_q/g_{eff}(m_q), where m_q is the mass of the fundamental fields and g_{eff}(m_q) is the effective coupling evaluated at the quark mass, i.e. g_{eff}^2(m_q)=\\gym^2N m_q^{p-3}. We consider the evolution of the meson spectra into the far infrared of three-dimensional SYM, where the gravity dual lifts to M-theory. We also argue that the mass scale appearing in the meson spectra is dictated by holography.

  3. Local optical potentials for mesons

    International Nuclear Information System (INIS)

    Full text: Local optical models are very useful to describe many nuclear reactions, with the parameters often determined from fits to data. Elastic meson-nucleus scattering can be described by such potentials, but there is a strong ambiguity in the parameters [1], making the model hard to apply. Consideration of meson-nucleus inelastic scattering to collective states can be described in the local DWBA, built on local optical models. If the parameters of the optical potential are varied so as to find simultaneous agreement with both elastic and inelastic scattering, the ambiguity is removed, and a unique local optical potential can be defined for mesons [2,3]. The methods used to determine these parameters, examples of the fits and the meaning of the results will be explained. The result is a widely usable set of parameters in a simple local optical potential for pion and kaon interactions with nuclei, found to describe these reactions over a wide range of beam energies and nuclear masses. This accomplishment should allow a wider range of nuclear reaction models to include mesons in a simple way

  4. Mesons in the nuclear Medium

    OpenAIRE

    Kotulla, Martin

    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.

  5. Vector meson electroproduction in QCD

    International Nuclear Information System (INIS)

    Based on the generalized QCD vector meson dominance model, we study the electroproduction of a vector meson off a proton in the QCD inspired eikonalized model. Numerical calculations for the total cross section σtot and differential cross section dσ/dt are performed for ρ, ω and φ meson electroproduction in this paper. Since gluons interact among themselves (self-interaction), two gluons can form a glueball with quantum numbers IG, JPC = 0+, 2++, decay width Γt ≈ 100 MeV, and mass of mG=2.23 GeV. The three gluons can form a three-gluon colorless bound state with charge conjugation quantum number C = -1, called the Odderon. The mediators of interactions between projectiles (the quark and antiquark pair fluctuated from the virtual photon) and the proton target (a three-quark system) are the tensor glueball and the Odderon. Our calculated results in the tensor glueball and Odderon exchange model fit to the existing data successfully, which evidently shows that our present QCD mechanism is a good description of meson electroproduction off a proton. It should be emphasized that our mechanism is different from the theoretical framework of Block et al. We also believe that the present study and its success are important for the investigation of other vector meson electro- and photoproduction at high energies, as well as for searching for new particles such as tensor glueballs and Odderons, which have been predicted by QCD and the color glass condensate model (CGC). Therefore, in return, it can test the validity of QCD and the CGC model. (authors)

  6. Vector meson electroproduction in QCD

    Institute of Scientific and Technical Information of China (English)

    LU Juan; CAI Xian-Hao; ZHOU Li-Juan

    2012-01-01

    Based on the generalized QCD vector meson dominance model,we study the electroproduction of a vector meson off a proton in the QCD inspired eikonalized model.Numerical calculations for the total cross section σtot and differential cross section dσ/dt are performed for p,ω and φ meson electroproduction in this paper.Since gluons interact among themselves (self-interaction),two gluons can form a glueball with quantum numbers IG,JPC =0+,2++,decay width Γt ≈ 100 MeV,and mass of mG=2.23 GeV.The three gluons can form a three-gluon colorless bound state with charge conjugation quantum number C =-1,called the Odderon.The mediators of interactions between projectiles (the quark and antiquark pair fluctuated from the virtual photon) and the proton target (a three-quark system) are the tensor glueball and the Odderon.Our calculated results in the tensor glueball and Odderon exchange model fit to the existing data successfully,which evidently shows that our present QCD mechanism is a good description of meson electroproduction off a proton.It should be emphasized that our mechanism is different from the theoretical framework of Block et al.We also believe that the present study and its success are important for the investigation of other vector meson electro- and photoproduction at high energies,as well as for searching for new particles such as tensor glueballs and Odderons,which have been predicted by QCD and the color glass condensate model (CGC).Therefore,in return,it can test the validity of QCD and the CGC model.

  7. Design and performance of a universal detector for the PSI/CERN B-Meson factory

    International Nuclear Information System (INIS)

    The paper describes the universal Detector which was proposed for the PSI B-Meson Factory in 1988. It includes a short history, aims and requirements, design and properties, R and D items under study and under discussion, and simulation results on the detector performance. The proposed detector fulfills all requirements for the physics program at a B-Meson Factory with small e+e- energy asymmetry as presently studied for the CERN-ISR tunnel

  8. Contributions of loops with dynamical vector mesons to masses and decay constants of pseudoscalar mesons and their quark mass dependence

    CERN Document Server

    Terschlüsen, Carla

    2016-01-01

    The contributions of one-loop diagrams with dynamical vector mesons to masses and decay constants of pseudoscalar mesons are determined. Hereby, a relativistic Lagrangian for both the pseudoscalar-meson octet and the vector-meson nonet is used. The vector mesons are given in the antisymmetric tensor representation. Both the differences between static and dynamical vector mesons and the differences between calculations with and without vector mesons are studied as functions of the light quark mass.

  9. Time-dependent Mott transition in the periodic Anderson model with nonlocal hybridization

    Science.gov (United States)

    Hofmann, Felix; Potthoff, Michael

    2016-08-01

    The time-dependent Mott transition in a periodic Anderson model with off-site, nearest-neighbor hybridization is studied within the framework of nonequilibrium self-energy functional theory. Using the two-site dynamical-impurity approximation, we compute the real-time dynamics of the optimal variational parameter and of different observables initiated by sudden quenches of the Hubbard-U and identify the critical interaction. The time-dependent transition is orbital selective, i.e., in the final state, reached in the long-time limit after the quench to the critical interaction, the Mott gap opens in the spectral function of the localized orbitals only. We discuss the dependence of the critical interaction and of the final-state effective temperature on the hybridization strength and point out the various similarities between the nonequilibrium and the equilibrium Mott transition. It is shown that these can also be smoothly connected to each other by increasing the duration of a U-ramp from a sudden quench to a quasi-static process. The physics found for the model with off-site hybridization is compared with the dynamical Mott transition in the single-orbital Hubbard model and with the dynamical crossover found for the real-time dynamics of the conventional Anderson lattice with on-site hybridization.

  10. Transverse Anderson localization of light: a tutorial review

    CERN Document Server

    Mafi, Arash

    2015-01-01

    This tutorial review gives an overview of the transverse Anderson localization of light in one and two transverse dimensions. A pedagogical approach is followed throughout the presentation, where many aspects of localization are illustrated by means of a few simple models. The tutorial starts with some basic aspects of random matrix theory, and light propagation through and reflection from a random stack of dielectric slabs. Transverse Anderson localization of light in one- and two-dimensional coupled waveguide arrays is subsequently established and discussed. Recent experimental observations of localization and image transport in disordered optical fibers are discussed. More advanced topics, such as hyper-transport in longitudinally varying disordered waveguides, the impact of nonlinearity, and propagation of partially coherent and quantum light, are also examined.

  11. Absence of Anderson localization in certain random lattices

    CERN Document Server

    Choi, Wonjun; Hooper, Ian R; Bernes, William L; Bertolotti, Jacopo

    2016-01-01

    We report on the transition between an Anderson localized regime and a conductive regime in a 1D scattering system with correlated disorder. We show experimentally that when long-range correlations, in the form of a power-law spectral density with power larger than 2, are introduced the localization length becomes much bigger than the sample size and the transmission peaks typical of an Anderson localized system merge into a pass band. As other forms of long-range correlations are known to have the opposite effect, i.e. to enhance localization, our results show that care is needed when discussing the effects of correlations, as different kinds of long-range correlations can give rise to very different behavior.

  12. Critical parameters from generalised multifractal analysis at the Anderson transition

    OpenAIRE

    Rodriguez, Alberto; Vasquez, Louella J.; Slevin, Keith; Römer, Rudolf A.

    2010-01-01

    We propose a generalization of multifractal analysis that is applicable to the critical regime of the Anderson localization-delocalization transition. The approach reveals that the behavior of the probability distribution of wavefunction amplitudes is sufficient to characterize the transition. In combination with finite-size scaling, this formalism permits the critical parameters to be estimated without the need for conductance or other transport measurements. Applying this method to high-pre...

  13. Quasiperiodic driving of Anderson localized waves in one dimension

    OpenAIRE

    Hatami, H.; Danieli, C.; Bodyfelt, J. D.; Flach, S

    2016-01-01

    We consider a quantum particle in a one-dimensional disordered lattice with Anderson localization, in the presence of multi-frequency perturbations of the onsite energies. Using the Floquet representation, we transform the eigenvalue problem into a Wannier-Stark basis. Each frequency component contributes either to a single channel or a multi-channel connectivity along the lattice, depending on the control parameters. The single channel regime is essentially equivalent to the undriven case. T...

  14. Smoothed universal correlations in the two-dimensional Anderson model

    OpenAIRE

    Uski, V.; Mehlig, B.; R.A. Romer; Schreiber, M.

    1998-01-01

    We report on calculations of smoothed spectral correlations in the two-dimensional Anderson model for weak disorder. As pointed out in (M. Wilkinson, J. Phys. A: Math. Gen. 21, 1173 (1988)), an analysis of the smoothing dependence of the correlation functions provides a sensitive means of establishing consistency with random matrix theory. We use a semiclassical approach to describe these fluctuations and offer a detailed comparison between numerical and analytical calculations for an exhaust...

  15. Perturbative Interpretation of Adaptive Thouless-Anderson-Palmer Free Energy

    OpenAIRE

    Yasuda, Muneki; Takahashi, Chako; Tanaka, Kazuyuki

    2016-01-01

    In conventional well-known derivation methods for the adaptive Thouless-Anderson-Palmer (TAP) free energy, special assumptions that are difficult to mathematically justify except in some mean-field models, must be made. Here, we present a new adaptive TAP free energy derivation method. Using this derivation technique, without any special assumptions, the adaptive TAP free energy can be simply obtained as a high-temperature expansion of the Gibbs free energy.

  16. Perturbative Interpretation of Adaptive Thouless-Anderson-Palmer Free Energy

    Science.gov (United States)

    Yasuda, Muneki; Takahashi, Chako; Tanaka, Kazuyuki

    2016-07-01

    In conventional well-known derivation methods for the adaptive Thouless-Anderson-Palmer (TAP) free energy, special assumptions that are difficult to mathematically justify except in some mean-field models, must be made. Here, we present a new adaptive TAP free energy derivation method. Using this derivation technique, without any special assumptions, the adaptive TAP free energy can be simply obtained as a high-temperature expansion of the Gibbs free energy.

  17. Spectra of Anderson Type Models with Decaying Randomness

    Indian Academy of Sciences (India)

    M Krishna; K B Sinha

    2001-05-01

    In this paper we consider some Anderson type models, with free parts having long range tails with the random perturbations decaying at different rates in different directions and prove that there is a.c. spectrum in the model which is pure. In addition, we show that there is pure point spectrum outside some interval. Our models include potentials decaying in all directions in which case absence of singular continuous spectrum is also shown.

  18. Many-body Anderson localization in one-dimensional systems

    Science.gov (United States)

    Delande, Dominique; Sacha, Krzysztof; Płodzień, Marcin; Avazbaev, Sanat K.; Zakrzewski, Jakub

    2013-04-01

    We show, using quasi-exact numerical simulations, that Anderson localization in a disordered one-dimensional potential survives in the presence of attractive interaction between particles. The localization length of the particles' center of mass—computed analytically for weak disorder—is in good agreement with the quasi-exact numerical observations using the time evolving block decimation algorithm. Our approach allows for simulation of the entire experiment including the final measurement of all atom positions.

  19. Experimental determination of critical exponents in Anderson localisation of light

    OpenAIRE

    Aegerter, Christof M.; Störzer, Martin; Maret, Georg

    2006-01-01

    Anderson localisation predicts a phase transition in transport, where the diffuse spread of particles comes to a halt with the introduction of a critical amount of disorder. This is due to constructive interference on closed multiple scattering loops which leads to a renormalisation of the diffusion coefficient. This can be described by a slowing-down of diffusion, where the diffusion coefficient decreases with time according to a power law with an exponent a. In the case of strong localisati...

  20. Non-random perturbations of the Anderson Hamiltonian

    CERN Document Server

    Molchanov, S

    2010-01-01

    The Anderson Hamiltonian $H_0=-\\Delta+V(x,\\omega)$ is considered, where $V$ is a random potential of Bernoulli type. The operator $H_0$ is perturbed by a non-random, continuous potential $-w(x) \\leq 0$, decaying at infinity. It will be shown that the borderline between finitely, and infinitely many negative eigenvalues of the perturbed operator, is achieved with a decay of $O(\\ln^{-2/d} |x|)$.

  1. Mass Spectra of Heavy-Light Mesons in Heavy Hadron Chiral Perturbation Theory

    CERN Document Server

    Alhakami, Mohammad H

    2016-01-01

    We study the masses of the low-lying charm and bottom mesons within the framework of heavy- hadron chiral perturbation theory. We work to third order in the chiral expansion, where meson loops contribute. In contrast to previous approaches, we use physical meson masses in evaluating these loops. This ensures that their imaginary parts are consistent with the observed widths of the D-mesons. The lowest odd- and even-parity, strange and nonstrange charm mesons provide enough constraints to determine only certain linear combinations of the low-energy constants (LECs) in the effective Lagrangian. We comment on how lattice QCD could provide further information to disentangle these constants. Then we use the results from the charm sector to predict the spectrum of odd- and even-parity of the bottom mesons. The predicted masses from our theory are in good agreement with experimentally measured masses for the case of the odd-parity sector. For the even-parity sector, the B-meson states have not yet been observed; thu...

  2. Model discrimination in pseudoscalar-meson photoproduction

    CERN Document Server

    Nys, J; Ireland, D G; Glazier, D I

    2016-01-01

    To learn about a physical system of interest, experimental results must be able to discriminate among models. We introduce a geometrical measure to quantify the distance between models for pseudoscalar-meson photoproduction in amplitude space. Experimental observables, with finite accuracy, map to probability distributions in amplitude space, and the characteristic width scale of such distributions needs to be smaller than the distance between models if the observable data are going to be useful. We therefore also introduce a method for evaluating probability distributions in amplitude space that arise as a result of one or more measurements, and show how one can use this to determine what further measurements are going to be necessary to be able to discriminate among models.

  3. Delta, iota and other meson spectroscopies

    International Nuclear Information System (INIS)

    This talk is given from the point of view of an experimentalist. Meson spectroscopy in the 1 to 3 GeV region is interesting because experiments exploring this region, in particular radiative psi decay, have found a rich structure of resonances too complicated to unravel with any one experiment, and not easily interpreted with any one theoretical model. None of the theoretical calculations predicting all kinds of interesting and exotic objects in this region is very convincing or reliable. Additional input from anti pp annihilation can be very useful in helping to find the answers to the following open questions: what exactly is this spectrum, what are the masses and quantum numbers of the resonances, as determined from analysis of data without theoretical prejudices; how is this spectrum described by QCD, is there evidence for new kinds of states like glue-balls, hybrids, axions, Higgses or multiquark exotics, and is there any evidence for new physics beyond QCD. 20 refs

  4. On Deusons or Deuteronlike Meson-Meson Bound States

    CERN Document Server

    Törnqvist, N A

    1994-01-01

    The systematics of deuteronlike two-meson bound states, {\\it deusons}, is discussed. Previous arguments that many of the present non-$q\\bar q$ states are such states are elaborated including, in particular, the tensor potential. For pseudoscalar states the important observation is made that the centrifugal barrier from the P-wave can be overcome by the $1/r^2$ and $1/r^3$ terms of the tensor potential. In the heavy meson sector one-pion exchange alone is strong enough to form at least deuteron-like $B\\bar B^*$ and $B^*\\bar B^*$ composites bound by approximately 50 MeV, while $D\\bar D^*$ and $D^*\\bar D^*$ states are expected near the threshold.

  5. Semileptonic decays of B meson into charmed meson

    International Nuclear Information System (INIS)

    Recent results on semileptonic decays of B meson into charmed meson using the CLEO detector at CESR are summarized. Ratios of the inclusive semileptonic branching fractions, B(B-→D0Xl-bar ν), B(bar B0→D+Xl-bar νXl-bar ν), and B(bar B0→D+) average B meson semileptonic branching fraction are reported. The branching fractions of the exclusive final states, B-→D0l-bar ν, B-→D0l-bar ν, and bar B0→D+l-bar ν are measured. The ratio of B(B-→D0l-bar ν) to B(B-→D0l-bar ν) and the polarization of the D*+ are obtained and compared with theoretical models. The value of |Vcb| is calculated from the exclusive branching fractions for various models. Finally, the lifetime ratio of the charged and neutral B's (τ+/τ0) is determined from the ratio of B(B-→D0l-bar ν) to B(bar B0→D+l-bar ν) to be 0.85±0.20+0.22-0.16

  6. K+-meson production in nuclei

    International Nuclear Information System (INIS)

    This report summarises the results of the physics programme, performed in the years 1998-2003, which became possible after taking into operation the ANKE spectrometer at an internal target position of the accelerator facility COSY-Juelich. Primary goal when building ANKE was to provide a tool which allows one to study processes leading to K+-meson production in interactions of protons with atomic nuclei, in particular at beam energies far below the free nucleon-nucleon threshold. From such data one hopes to extract information about the influence of the nuclear medium on elementary K+-production processes (i.e. in free proton-proton interactions), about the in-medium properties of this meson, and about collective effects in nuclear matter. The construction of ANKE and the K+-detection systems was started in 1989. After the integration of ANKE into the COSY accelerator ring in 1998, inclusive K+-momentum spectra were measured in a first series of experiments (p+A → K+X for different target nuclei A=C, Cu, Ag, Au). These data reveal a high degree of collectivity in the target nuclei and, for the first time, allow one to extract the nuclear potential (or ''in-medium mass'') of K+ mesons at normal nuclear density with high accuracy. The ANKE data on K+ production in proton-deuteron interactions indicate a large production cross section on neutrons, as compared to proton targets. This fact must be taken into account, e.g., for the theoretical description of heavy ion data. In the second phase of the experimental program, K+ mesons from protoncarbon interactions were measured in coincidence with protons and deuterons (p+C → K+ (p or d)X). These novel data yield information about the kaon production mechanisms and give evidence for cluster-formation processes. Corresponding coincidence data for proton-proton collisions (p+p → K+ anti K0 d) revealed that K anti K -pair production close to threshold is dominated by kaons produced in a relative S-wave. This has been

  7. In-medium effects on the φ meson

    International Nuclear Information System (INIS)

    The temperature dependence of the φ meson mass and its decay width (φ→K bar K) have been studied from an effective nonlinear chiral Lagrangian in SU(3). The effective mass has been obtained from the pole position of the full propagator. The width has also been calculated. It has been found that the mass decreases with temperature very slowly whereas the decay width increases quite sharply. Possible consequences on the QGP signals are discussed. copyright 1997 The American Physical Society

  8. N* and Meson Resonances in J/psi decays

    CERN Document Server

    Zou Bing Song

    2003-01-01

    Over sixty million J/psi events have been collected by the BES Collaboration at the Beijing Electron-Positron Collider (BEPC). J/psi decays provide an excellent place for studying excited nucleons and hyperons -- N*, $\\Lambda^*$, $\\Sigma^*$ and $\\Xi^*$ resonances, as well as meson resonances, including possible glueballs and hybrids. Physics objectives, recent results and future prospects of light hadron spectroscopy at BEPC are presented.

  9. CP Violation in B Meson Decays: Experimental Results

    Energy Technology Data Exchange (ETDEWEB)

    Lanceri, Livio; /Trieste U. /INFN, Trieste

    2005-08-30

    CP violation is intimately connected with the puzzle of matter-antimatter asymmetry and baryogenesis. In the Standard Model of particle physics, the observed CP violation phenomena are accounted for by the Cabibbo-Kobayashi-Maskawa mechanism involving a phase in the quark mixing matrix. This paper is devoted to a review of the experimental status of CP violation in the decays of B mesons.

  10. CP measurement in quantum teleportation of neutral mesons

    International Nuclear Information System (INIS)

    Quantum teleportation using neutral pseudoscalar mesons shows novel connections between particle physics and quantum information. The projection basis, which is crucial in the teleportation process, is determined by the conservation laws of particle physics and is different from the Bell basis, as in the usual case. Here we show that one can verify the teleportation process by CP measurement. This method significantly simplifies the high energy quantum teleportation protocol. Especially, it is rigorous and independent of whether CP is violated in weak decays. This method can also be applied to general verification of Einstein-Podolsky-Rosen correlations in particle physics. (orig.)

  11. Resurrection of the $\\sigma$ meson

    CERN Document Server

    Törnqvist, N A; Tornqvist, Nils A; Roos, Matts

    1995-01-01

    It is shown from a very general model and an analysis of data on the lightest 0++ meson nonet that the f0(980) and f0(1200) resonance poles are two manifestations of the same ss state. Similarily the a0(980) and the a0(1450) are likely to be two manifestations of the same qq state. On the other hand, the uu+dd state, when unitarized and strongly distorted by hadronic mass shifts, becomes an extremely broad Breit-Wigner-like background, m=860 MeV, Gamma=880 MeV, with its pole at s=(0.158-i0.235) GeV^2. This we identify with the sigma meson required by models for spontaneous breaking of chiral symmetry.

  12. Primakoff production of hybrid mesons

    International Nuclear Information System (INIS)

    The viability of Primakoff technique in searching for hybrid states, and exotic JPC = 1-+ isovector meson bar ρ in particular, is discussed. Results of searches for Primakoff production of an bar ρ in ρπ and ηπ final states produced in high energy interactions of pions with large-Z nuclei are reviewed, and the limits for the radiative coupling Γ( bar ρ+ → π+γ) are presented. Based on available experimental information, electromagnetic production rate estimates are given for the favored bar ρ → πf1(1285) channel. It is argued that a dedicated Primakoff production experiment can be sensitive to values of Γ( bar ρ+ → π+γ) ∼ keV, which makes such measurement a very interesting option for doing spectroscopy of gluonic (and conventional) meson states in the 1.5 ∼ 3 GeV mass range. 18 references, 2 figures

  13. Search for popcorn mesons in events with two charmed baryons

    Science.gov (United States)

    Hartfiel, Brandon

    The physics of this dissertation is divided into two parts. The first part measures the Λc → pi kp continuum momentum spectrum at a center of mass energy of 10.54 GeV/c, which is just below the Υ(4s) resonance. The data sample consists of 15,400 Λc baryons from 9.46 fb-1 of integrated luminosity collected with the BaBar detector at the PEP-II asymmetric B factory at the Stanford Linear Accelerator Center. 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 Λc → K0p mode, and look for events with a Λc+ and a Λ c- 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-1. We find 619 events after background subtraction. After a subtraction of 1.06+/-.09 charged pions coming from decays of known resonances to Λc + npi, we are left with 2.63+/-.21 additional charged pious in each of these events. This is significantly higher than the .5 popcorn mesons per bayon 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.

  14. Search for Popcorn Mesons in Events with Two Charmed Baryons

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Baryons and Mesons with Beauty

    OpenAIRE

    Goldstein, Gary R.; Wali, Kameshwar C.

    2007-01-01

    Recent experimental findings of several mesons and baryons with "beauty" and "charm" as flavors remind us of the days when strangeness was discovered, and how its inclusion led to SU(3)-flavor symmetry with enormous success in the classification of the "proliferated" states into SU(3) multiplets. One of the key elements was the successful application of the first order perturbation in symmetry breaking, albeit what then appeared to be huge mass differences, and the prediction of new states th...

  16. Properties of the D mesons

    International Nuclear Information System (INIS)

    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

  17. Exclusive meson production at HERMES

    CERN Document Server

    Manaenkov, Sergey

    2016-01-01

    The data were accumulated with the HERMES forward spectrometer using the 27.6 GeV longitudinally polarized electron or positron beam of HERA. Exclusive electroproduction of $\\omega$ mesons on unpolarized hydrogen and deuterium targets is studied in the kinematic region of $Q^2>1.0$ GeV$^2$, 3.0 GeV $< W <$ 6.3 GeV, and $-t'< 0.2 $ GeV$^{2}$, while for $\\rho^0$-meson production on a transversely polarized hydrogen target $-t'< 0.4$ GeV$^{2}$ is used. Spin-density matrix elements for $\\omega$ production are presented in projections of $Q^2$ or $-t'$, while the ratios of the helicity amplitudes for the reaction $\\gamma^*+p \\to \\rho^0+p$ are obtained in the entire kinematic region. The usage of the transversely polarized target allows for the first time the extraction of the ratios of certain nucleon-helicity-flip amplitudes to the natural-parity exchange amplitude $T_{0\\frac{1}{2}0\\frac{1}{2}}$ without the nucleon-helicity flip describing the longitudinal $\\rho^0$-meson production by the longitudinal...

  18. Dynamical meson melting in holography

    International Nuclear Information System (INIS)

    We discuss mesons in thermalizing gluon backgrounds in the N=2 supersymmetric QCD using the gravity dual. We numerically compute the dynamics of a probe D7-brane in the Vaidya-AdS geometry that corresponds to a D3-brane background thermalizing from zero to finite temperatures by energy injection. In static backgrounds, it has been known that there are two kinds of brane embeddings where the brane intersects the black hole or not. They correspond to the phases with melted or stable mesons. In our dynamical setup, we obtain three cases depending on final temperatures and injection time scales. The brane stays outside of the black hole horizon when the final temperature is low, while it intersects the horizon and settles down to the static equilibrium state when the final temperature is high. Between these two cases, we find the overeager case where the brane dynamically intersects the horizon although the final temperature is not high enough for a static brane to intersect the horizon. The interpretation of this phenomenon in the dual field theory is meson melting due to non-thermal effects caused by rapid energy injection. In addition, we comment on the late time evolution of the brane and a possibility of its reconnection

  19. From the ψ to charmed mesons

    International Nuclear Information System (INIS)

    This talk deals with the author's recollections about the discoveries of the J/ψ the ψ' as well as psion spectroscopy and charmed mesons. He gives a chronology for the ψ and ψ' discoveries. He also discusses the events which led to the charmed meson discovery as well as detailed discussions on the proof that the resonance observed in the K- π+ system, at 1,865 MeV, was indeed the predicted charmed meson

  20. Meson's Correlation Functions in a Nuclear Medium

    CERN Document Server

    Park, Chanyong

    2016-01-01

    We investigate meson's spectrum, decay constant and form factor in a nuclear medium through holographic two- and three-point correlation functions. To describe a nuclear medium composed of protons and neutrons, we consider a hard wall model on the thermal charged AdS geometry and show that due to the isospin interaction with a nuclear medium, there exist splittings of the meson's spectrum, decay constant and form factor relying on the isospin charge. In addition, we show that the rho-meson's form factor describing an interaction with pseudoscalar fluctuation decreases when the nuclear density increases, while the interaction with a longitudinal part of an axial vector meson increases.

  1. D mesons in a magnetic field

    CERN Document Server

    Gubler, Philipp; Lee, Su Houng; Oka, Makoto; Ozaki, Sho; Suzuki, Kei

    2015-01-01

    We investigate the mass spectra of open heavy flavor mesons in an external constant magnetic field within QCD sum rules. Spectral ans\\"atze on the phenomenological side are proposed in order to properly take into account mixing effects between the pseudoscalar and vector channels, and the Landau levels of charged mesons. The operator product expansion is implemented up to dimension--5 operators. As a result, we find for neutral D mesons a significant positive mass shift that goes beyond simple mixing effects. In contrast, charged D mesons are further subject to Landau level effects, which together with the mixing effects almost completely saturate the mass shifts obtained in our sum rule analysis.

  2. Meson's correlation functions in a nuclear medium

    Science.gov (United States)

    Park, Chanyong

    2016-09-01

    We investigate meson's spectrum, decay constant and form factor in a nuclear medium through holographic two- and three-point correlation functions. To describe a nuclear medium composed of protons and neutrons, we consider a hard wall model on the thermal charged AdS geometry and show that due to the isospin interaction with a nuclear medium, there exist splittings of the meson's spectrum, decay constant and form factor relying on the isospin charge. In addition, we show that the ρ-meson's form factor describing an interaction with pseudoscalar fluctuation decreases when the nuclear density increases, while the interaction with a longitudinal part of an axial vector meson increases.

  3. Photoproduction of vector mesons in nuclei

    International Nuclear Information System (INIS)

    The mass of vector mesons in the nuclear medium is of great interest in strong interaction dynamics because vector meson masses could decrease with increasing baryonic density as a consequence of chiral symmetry restoration. The purpose of this work is to define an observable sensitive to vector meson masses at nuclear matter density. This short paper reports some preliminary results which suggest that the quantum interference between (e+e-) pairs emitted in the photoproduction of ρ- and ω- mesons near threshold in heavy nuclei could be such quantity. (J.S.). 4 refs., 2 figs

  4. Single spin asymmetry for charm mesons

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  5. Single spin asymmetry for charm mesons

    International Nuclear Information System (INIS)

    We study single spin asymmetries of D0 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.)

  6. Leveraging Anderson Acceleration for improved convergence of iterative solutions to transport systems

    International Nuclear Information System (INIS)

    In this note we demonstrate that using Anderson Acceleration (AA) in place of a standard Picard iteration can not only increase the convergence rate but also make the iteration more robust for two transport applications. We also compare the convergence acceleration provided by AA to that provided by moment-based acceleration methods. Additionally, we demonstrate that those two acceleration methods can be used together in a nested fashion. We begin by describing the AA algorithm. At this point, we will describe two application problems, one from neutronics and one from plasma physics, on which we will apply AA. We provide computational results which highlight the benefits of using AA, namely that we can compute solutions using fewer function evaluations, larger time-steps, and achieve a more robust iteration

  7. Leveraging Anderson Acceleration for improved convergence of iterative solutions to transport systems

    Energy Technology Data Exchange (ETDEWEB)

    Willert, Jeffrey; Taitano, William T.; Knoll, Dana

    2014-09-15

    In this note we demonstrate that using Anderson Acceleration (AA) in place of a standard Picard iteration can not only increase the convergence rate but also make the iteration more robust for two transport applications. We also compare the convergence acceleration provided by AA to that provided by moment-based acceleration methods. Additionally, we demonstrate that those two acceleration methods can be used together in a nested fashion. We begin by describing the AA algorithm. At this point, we will describe two application problems, one from neutronics and one from plasma physics, on which we will apply AA. We provide computational results which highlight the benefits of using AA, namely that we can compute solutions using fewer function evaluations, larger time-steps, and achieve a more robust iteration.

  8. An Anderson Impurity Model for Efficient Sampling of Adiabatic Potential Energy Surfaces of Transition Metal Complexes

    CERN Document Server

    La Bute-Montiago X; Cox, D L

    2004-01-01

    We present a model intended for rapid sampling of ground and excited state potential energy surfaces for first-row transition metal active sites. The method is computationally inexpensive and is suited for dynamics simulations where (1) adiabatic states are required "on-the-fly" and (2) the primary source of the electronic coupling between the diabatic states is the perturbative spin-orbit interaction among the 3d electrons. The model Hamiltonian we develop is a variant of the Anderson impurity model and achieves efficiency through a physically motivated basis set reduction based on the large value of the d-d Coulomb interaction U_{d} and a Lanczos matrix diagonalization routine to solve for eigenvalues. The model parameters are constrained by fits to the partial density of states (PDOS) obtained from ab initio density functional theory calculations. For a particular application of our model we focus on electron-transfer occuring between cobalt ions solvated by ammonium, incorporating configuration interactio...

  9. Efficient Localization Bounds in a Continuous N-Particle Anderson Model with Long-Range Interaction

    Science.gov (United States)

    Chulaevsky, Victor

    2016-04-01

    We establish strong dynamical and exponential spectral localization for a class of multi-particle Anderson models in a Euclidean space with an alloy-type random potential and a sub-exponentially decaying interaction of infinite range. For the first time in the mathematical literature, the uniform decay bounds on the eigenfunction correlators (EFCs) at low energies are proved, in the multi-particle continuous configuration space, in the (symmetrized) norm-distance, which is a natural distance in the multi-particle configuration space, and not in the Hausdorff distance. This results in uniform bounds on the EFCs in arbitrarily large but bounded domains in the physical configuration space, and not only in the actually infinite space, as in prior works on multi-particle localization in Euclidean spaces.

  10. B mesons phenomenology and lattice QCD

    International Nuclear Information System (INIS)

    We have studied some phenomenological aspects of the B meson physics by using lattice QCD, which is a non perturbative method (based on the first principles of Quantum Field Theory) of computing Green functions of the theory. Pionic couplings g1 and g2, parameterizing the effective chiral Lagrangian which describes interactions between heavy-light mesons and soft pions, have been computed beyond the quenched approximation (at Nf = 2). We have renormalized the operator q-barγμγ5q non perturbatively by using chiral Ward identities. We obtain g1 = 0.4/0.6 and g2 = -0.1/-0.3. We have estimated from an un-quenched simulation (at Nf = 2) the strange quark mass: the non perturbative renormalisation scheme RI-MOM has been applied. After the matching in the MS scheme the result is ms(2 GeV) = 101 ± 8(-0,+25) MeV. We have proposed a method to calculate on the lattice the Heavy Quark Effective Theory form factors of the semileptonic transitions B → D** at zero recoil. The renormalisation constant of the operator h-barγiγ5Djh has been computed at one-loop order of the perturbation theory. We obtain τ1/2(1) = 0.3/0.5 and τ3/2(1) 0.5/0.7. Eventually the bag parameter BBs associated the Bs - Bs-bar mixing amplitude in the Standard Model has been estimated in the quenched approximation by using for the strange quark an action which verifies the chiral symmetry at finite lattice spacing a. Thus systematic errors are significantly reduced in the renormalisation procedure because the spurious mixing of the four-fermion operator h-barγμLqh-barγμLq with four-fermion operators of different chirality is absent. The result is BBs = 0.92(3). (author)

  11. Precision for B-meson matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Guazzini, D.; Sommer, R. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Tantalo, N. [INFN sezione ' ' Tor Vergata' ' , Rome (Italy)]|[Centro E. Fermi, Rome (Italy)

    2007-10-15

    We demonstrate how HQET and the Step Scaling Method for B-physics, pioneered by the Tor Vergata group, can be combined to reach a further improved precision. The observables considered are the mass of the b-quark and the B{sub s}-meson decay constant. The demonstration is carried out in quenched lattice QCD. We start from a small volume, where one can use a standard O(a)-improved relativistic action for the b-quark, and compute two step scaling functions which relate the observables to the large volume ones. In all steps we extrapolate to the continuum limit, separately in HQET and in QCD for masses below m{sub b}. The physical point m{sub b} is then reached by an interpolation of the continuum results in 1/m. The essential, expected and verified, feature is that the step scaling functions have a weak mass-dependence resulting in an easy interpolation to the physical point. With r{sub 0}=0.5 fm and the experimental B{sub s} and K masses as input, we find F{sub B{sub s}}=191(6) MeV and 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. This approach seems very promising for full QCD. (orig.)

  12. Rare decays of B-mesons

    International Nuclear Information System (INIS)

    This article is dedicated to the memory of Andrei D. Sakharov, a great scientist and human rights activist. Sakharov was blessed with the rare gift of prophetic prediction in matters concerning both science and society. His paper in 1967 on the baryon asymmetry of the universe relating it to the baryon instability, CP-violation, and thermodynamic non-equilibrium, was a very long shot. In view of subsequent theoretical developments in grand unified theories of elementary particle physics and cosmology, where the Sakharov conditions can be accommodated, this paper represents indeed a very fine example of scientific genius and prophecy. His political judgement, exemplified by his visionary essay Progress, Coexistence, and Intellectual Freedom, written in 1968, was equally stunning. Among other topics Sakharov was also very much interested in physics of the heavy quarks. In this paper we review theoretical predictions about an interesting aspect of heavy quark physics, namely rare phenomena in the decays of B-meson involving flavor changing neutral current (FCNC) processes

  13. Applied nuclear physics in support of SBSS

    Energy Technology Data Exchange (ETDEWEB)

    Strottman, D.

    1995-10-01

    Since the advent of the 800-MeV proton linear accelerator over 3 decades ago, the facilities on the Clinton P. Anderson Meson Physics Facility (LAMPF) mesa have pioneered many developments that provide unique capabilities within the Department of Energy (DOE) complex and in the world. New technologies based on the use of the world`s most intense, medium-energy linac, LAMPF, are being developed. They include destruction of long-lived components of nuclear waste, plutonium burning, energy production, production of tritium, and experiments for the science-based stockpile stewardship (SBSS) program. The design, assessment, and safety analysis of potential facilities involve the understanding of complex combinations of nuclear processes, which in turn establish new requirements on nuclear data that transcend the traditional needs of the fission and fusion reactor communities. Other areas of technology such as neutron and proton therapy applications are also placing new requirements on nuclear data. The proposed Los Alamos Neutron Science Center (LANSCE) now under discussion combined with the appropriate instrumentation will have unique features and capabilities of which there were previously only aspirations.

  14. Density of states controls Anderson localization in disordered photonic crystal waveguides

    DEFF Research Database (Denmark)

    Garcia-Fernández, David; Smolka, Stephan; Stobbe, Søren;

    2010-01-01

    We prove Anderson localization in a disordered photonic crystal waveguide by measuring the ensemble-averaged extinction mean-free path, ℓe, which is controlled by the dispersion in the photon density of states (DOS) of the photonic crystal waveguide. Except for the very low DOS case, where out...... demonstrates the close relation between Anderson localization and the DOS in disordered photonic crystals, which opens a promising route to controlling and exploiting Anderson-localized modes for efficient light confinement....

  15. Experimental Observation of Two-Dimensional Anderson Localization with the Atomic Kicked Rotor

    OpenAIRE

    Manai, Isam; Clément, Jean-François; Chicireanu, Radu; Hainaut, Clément; Garreau, Jean Claude; Szriftgiser, Pascal; Delande, Dominique

    2015-01-01

    Dimension 2 is expected to be the lower critical dimension for Anderson localization in a time-reversal-invariant disordered quantum system: the dynamics is generically localized in dimension lower than 2, while it presents a transition from a diffusive regime at weak disorder to a localized regime at strong disorder in dimension larger than 2. We use an atomic quasiperiodically kicked rotor – equivalent to a two-dimensional Anderson-like model – to experimentally study Anderson localization ...

  16. Price-Anderson Nuclear Safety Enforcement Program. 1996 Annual report

    International Nuclear Information System (INIS)

    This first annual report on DOE's Price Anderson Amendments Act enforcement program covers the activities, accomplishments, and planning for calendar year 1996. It also includes the infrastructure development activities of 1995. It encompasses the activities of the headquarters' Office of Enforcement in the Office of Environment, Safety and Health (EH) and Investigation and the coordinators and technical advisors in DOE's Field and Program Offices and other EH Offices. This report includes an overview of the enforcement program; noncompliances, investigations, and enforcement actions; summary of significant enforcement actions; examples where enforcement action was deferred; and changes and improvements to the program

  17. Transversal Anderson localization of sound in acoustic waveguide arrays

    International Nuclear Information System (INIS)

    We present designs of one-dimensional acoustic waveguide arrays and investigate wave propagation inside. Under the condition of single identical waveguide mode and weak coupling, the acoustic wave motion in waveguide arrays can be modeled with a discrete mode-coupling theory. The coupling constants can be retrieved from simulations or experiments as the function of neighboring waveguide separations. Sound injected into periodic arrays gives rise to the discrete diffraction, exhibiting ballistic or extended transport in transversal direction. But sound injected into randomized waveguide arrays readily leads to Anderson localization transversally. The experimental results show good agreement with simulations and theoretical predictions. (paper)

  18. Note: Work function change measurement via improved Anderson method

    International Nuclear Information System (INIS)

    We propose the modification to the Anderson method of work function change (Δϕ) measurements. In this technique, the kinetic energy of the probing electrons is already low enough for non-destructive investigation of delicate molecular systems. However, in our implementation, all electrodes including filament of the electron gun are polarized positively. As a consequence, electron bombardment of any elements of experimental system is eliminated. Our modification improves cleanliness of the ultra-high vacuum system. As an illustration of the solution capabilities, we present Δϕ of the Ag(100) surface induced by cobalt phthalocyanine layers

  19. The parabolic Anderson model and long-range percolation

    OpenAIRE

    Erhard, Dirk

    2014-01-01

    This thesis has two parts. The first part deals with the parabolic Anderson model, which is a stochastic differential equation. It models the evolution of a field of particles performing independent simple random walks with binary branching. The focus of this work is on the exponential growth rate of the solution, where several basic properties are derived. The second part deals with two long-range percolation models. The occupied set of the first model is obtained by taking the union of a co...

  20. Note: Work function change measurement via improved Anderson method

    Energy Technology Data Exchange (ETDEWEB)

    Sabik, A., E-mail: sabik@ifd.uni.wroc.pl; Gołek, F.; Antczak, G. [Institute of Experimental Physics, University of Wrocław, Wrocław (Poland)

    2015-05-15

    We propose the modification to the Anderson method of work function change (Δϕ) measurements. In this technique, the kinetic energy of the probing electrons is already low enough for non-destructive investigation of delicate molecular systems. However, in our implementation, all electrodes including filament of the electron gun are polarized positively. As a consequence, electron bombardment of any elements of experimental system is eliminated. Our modification improves cleanliness of the ultra-high vacuum system. As an illustration of the solution capabilities, we present Δϕ of the Ag(100) surface induced by cobalt phthalocyanine layers.

  1. Implementation of legislation amending the Price--Anderson Act

    International Nuclear Information System (INIS)

    Proposed amendments for the implementation of the Price-Anderson Act require both persons licensed to possess plutonium in the amount of 5 kilograms or more and persons licensed to process plutonium in the amount of 1 kilogram or more for use in plutonium processing and fuel fabrication plants to maintain financial protection in the amount of $125 million. Indemnity coverage would be extended to such licensee at $5,000 per year. The Commission does not intend to extend separate coverage under the Act to transportation of nuclear materials. A proposed date of implementation is August 1977

  2. Quasiperiodic driving of Anderson localized waves in one dimension

    Science.gov (United States)

    Hatami, H.; Danieli, C.; Bodyfelt, J. D.; Flach, S.

    2016-06-01

    We consider a quantum particle in a one-dimensional disordered lattice with Anderson localization in the presence of multifrequency perturbations of the onsite energies. Using the Floquet representation, we transform the eigenvalue problem into a Wannier-Stark basis. Each frequency component contributes either to a single channel or a multichannel connectivity along the lattice, depending on the control parameters. The single-channel regime is essentially equivalent to the undriven case. The multichannel driving increases substantially the localization length for slow driving, showing two different scaling regimes of weak and strong driving, yet the localization length stays finite for a finite number of frequency components.

  3. Multi-Scale Jacobi Method for Anderson Localization

    Science.gov (United States)

    Imbrie, John Z.

    2015-11-01

    A new KAM-style proof of Anderson localization is obtained. A sequence of local rotations is defined, such that off-diagonal matrix elements of the Hamiltonian are driven rapidly to zero. This leads to the first proof via multi-scale analysis of exponential decay of the eigenfunction correlator (this implies strong dynamical localization). The method has been used in recent work on many-body localization (Imbrie in On many-body localization for quantum spin chains, arXiv:1403.7837 URL"/> , 2014).

  4. Strong decays of vector mesons to pseudoscalar mesons in the relativistic quark model

    CERN Document Server

    Ebert, D; Galkin, V O

    2014-01-01

    Strong decays of vector ($^3S_1$) mesons to the pair of pseudoscalar ($^1S_0$) mesons are considered in the framework of the microscopic decay mechanism and the relativistic quark model based on the quasipotential approach. The quark-antiquark potential, which was previously used for the successful description of meson spectroscopy and electroweak decays, is employed as the source of the $q\\bar q$ pair creation. The relativistic structure of the decay matrix element, relativistic contributions and boosts of the meson wave functions are comprehensively taken into account. The calculated rates of strong decays of light, heavy-light mesons and heavy quarkonia agree well with available experimental data.

  5. Decay constants of the charmed tensor mesons at finite temperature

    Science.gov (United States)

    Azizi, K.; Sundu, H.; Türkan, A.; Veliev, E. Veli

    2016-01-01

    Investigation of the thermal properties of the mesons with higher spin is one of the important problems in the hadron physics. At finite temperature, the Lorentz invariance is broken by the choice of a preferred frame of reference and some new operators appear in the Wilson expansion. Taking into account these additional operators, we calculate the thermal two-point correlation function for D2*(2460 ) and Ds2 *(2573 ) tensor mesons. In order to perform the numerical analysis, we use the fermionic part of the energy density obtained both from lattice QCD and Chiral perturbation theory. We also use the temperature dependent continuum threshold and show that the values of the decay constants decrease considerably near to the critical temperature compared to their values in the vacuum. Our results at zero temperature are in good consistency with predictions of other nonperturbative models.

  6. Properties of magnetized neutral mesons within a full RPA evaluation

    CERN Document Server

    Avancini, Sidney S; Pinto, Marcus B

    2016-01-01

    We consider the two flavor Nambu--Jona-Lasinio model within the RPA framework to evaluate the masses of the $\\sigma$ and $\\pi^0$ mesons and the $\\pi^0$ decay constant in the presence of a magnetic field at vanishing temperatures and baryonic densities. The present work extends other RPA applications by fully considering the external momenta, which enter the integrals representing the magnetized polarization tensor, so that more accurate results can be obtained in the evaluation of physical quantities containing pionic contributions. As we show, this technical improvement generates results which agree well with those produced by lattice simulations and chiral perturbation theory. Our method may also prove to be useful in future evaluations of quantities such as the shear viscosity and the equation of state of magnetized quark matter with mesonic contributions.

  7. Meson exchange model for the nucleon-nucleon interaction

    International Nuclear Information System (INIS)

    Nucleon-nucleon interactions obtained from several models for the field theoretic scattering amplitude are studied. The interaction includes contributions from one-pion and one-omega exchange and from two-pion exchange as calculated in a dispersion theory framework. The resulting interaction is regularized by a cut-off factor obtained by the eikonal approximation to multiple vector meson exchange processes. The Blankenbecler-Sugar equation is solved with the interaction and nucleon-nucleon scattering phase parameters are computed. For the best model good agreement with phenomenological phase parameters is achieved for physically reasonable values of the meson-nucleon coupling constants and the spectral functions needed for the evaluation of the two-pion exchange effects. The deuteron wave function is computed as are the deuteron charge and quadrupole form factors. The interaction is shown to have significantly weaker short-range repulsion than commonly found in local phenomenological potentials and in one-boson exchange models. (Auth.)

  8. Charmless nonleptonic decays into scalar and pseudoscalar mesons

    Indian Academy of Sciences (India)

    B Mawlong

    2007-10-01

    The charmless nonleptonic decay modes → 0 () involving a scalar and a pseudoscalar meson in the final state are studied. The scalar meson 0 is considered as a $q\\bar{q}$ state, as favored by some recent studies. Using the generalized factorization approach, the branching ratios and CP violation parameters are computed for these modes. The form factors are calculated using the results from relativistic light front quark model and the ISGW2 model. It is found that the direct CP violation parameters in these modes are small. However, the obtained branching ratios are not in agreement with the experimental data. Therefore, these modes may be considered as possible probes for new physics.

  9. Experimental Observation of Two-Dimensional Anderson Localization with the Atomic Kicked Rotor.

    Science.gov (United States)

    Manai, Isam; Clément, Jean-François; Chicireanu, Radu; Hainaut, Clément; Garreau, Jean Claude; Szriftgiser, Pascal; Delande, Dominique

    2015-12-11

    Dimension 2 is expected to be the lower critical dimension for Anderson localization in a time-reversal-invariant disordered quantum system. Using an atomic quasiperiodic kicked rotor-equivalent to a two-dimensional Anderson-like model-we experimentally study Anderson localization in dimension 2 and we observe localized wave function dynamics. We also show that the localization length depends exponentially on the disorder strength and anisotropy and is in quantitative agreement with the predictions of the self-consistent theory for the 2D Anderson localization. PMID:26705619

  10. Vacuum fluctuation effects on the ρ-meson mass and the one-ρ exchange potential at finite temperature and density

    International Nuclear Information System (INIS)

    Based on thermofield dynamics, the temperature- and density-dependent effective mass and screening mass of ρ meson have been calculated. The effects of vacuum fluctuation corrections through effective nucleon mass are examined. We have shown that vacuum fluctuations give an important correction to the self-energy of the ρ meson and lead to a reduction of the ρ-meson mass in hot and dense matter. The temperature and density dependence of one-ρ-meson exchange potential with vacuum fluctuation correction is also given. copyright 1997 The American Physical Society

  11. Heavy Mesons in Nuclear Matter and Nuclei

    CERN Document Server

    Tolos, Laura; Garcia-Recio, Carmen; Molina, Raquel; Nieves, Juan; Oset, Eulogio; Ramos, Angels; Romanets, Olena; Salcedo, Lorenzo Luis; Torres-Rincon, Juan M

    2014-01-01

    Heavy mesons in nuclear matter and nuclei are analyzed within different frameworks, paying a special attention to unitarized coupled-channel approaches. Possible experimental signatures of the properties of these mesons in matter are addressed, in particular in connection with the future FAIR facility at GSI.

  12. Heavy Mesons in Nuclear Matter and Nuclei

    International Nuclear Information System (INIS)

    Heavy mesons in nuclear matter and nuclei are analyzed within different frameworks, paying a special attention to unitarized coupled-channel approaches. Possible experimental signatures of the properties of these mesons in matter are addressed, in particular in connection with the future FAIR facility at GSI

  13. Experimental evidence for hadroproduction of exotic mesons

    International Nuclear Information System (INIS)

    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

  14. New results of radiative meson decays

    International Nuclear Information System (INIS)

    We have investigated Coulomb dissociation (the Primakoff effect) of high energy charged r and K mesons on heavy nuclei. New values for the electromagnetic transition rates G(p-→rg) and G(K-→K-g) have been extracted from the data. Some preliminary data for the Primakoff production of higher meson excitations will also be presented

  15. Pseudotensor mesons as three-body resonances

    CERN Document Server

    Roca, L

    2011-01-01

    We show that the lightest pseudotensor mesons J^{PC}=2^-+ can be regarded as molecules made of a pseudoscalar (P) 0^-+ and a tensor 2^++ meson, where the latter is itself made of two vector (V) mesons. The idea stems from the fact that the vector-vector interaction in s-wave and spin 2 is very strong, to the point of generating the 2^++ tensor mesons. On the other hand the interaction of a pseudoscalar with a vector meson in s-wave is also very strong and it generates dynamically the lightest axial-vector mesons. Therefore we expect the PVV interaction to be strongly attractive and thus able to build up quasibound PVV resonances. We calculate the three body PVV interaction by using the fixed center approximation to the Faddeev equations where the two vectors are clustered forming a tensor meson. We find clear resonant structures which can be identified with the pi_2(1670), eta_2(1645) and K^*_2(1770) (2^-+) pseudotensor mesons.

  16. Sigma meson in heavy ion collision

    International Nuclear Information System (INIS)

    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)

  17. Studies of Excited $D$ mesons in $B$ meson decays

    CERN Document Server

    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...

  18. Results for light pseudoscalar mesons

    CERN Document Server

    Bazavov, A; DeTar, C; Du, X; Freeman, W; Gottlieb, Steven; Heller, Urs M; Hetrick, J E; Laiho, J; Levkova, L; Oktay, M B; Osborn, J; Sugar, R; Toussaint, D; Van de Water, R S

    2010-01-01

    We present the current status of the MILC collaboration's calculations of the properties of the light pseudoscalar meson sector. We use asqtad staggered ensembles with 2+1 dynamical flavors down to $a \\approx 0.045$ fm and light quark mass down to 0.05 $m_s$. Here we describe fits to the data using chiral forms from SU(3) chiral perturbation theory, including all staggered taste violations at NLO and the continuum NNLO chiral logarithms. We emphasize issues of convergence of the chiral expansion.

  19. Some Ergodic Theorems for a Parabolic Anderson Model

    Institute of Scientific and Technical Information of China (English)

    Yong LIU; Feng Xia YANG

    2012-01-01

    In this paper,we study some ergodic theorems of a class of linear systems of interacting diffusions,which is a parabolic Anderson model.First,under the assumption that the transition kernel a =(a(i,j))i,j∈s is doubly stochastic,we obtain the long-time convergence to an invariant probability measure Vh starting from a bounded a-harmonic function h based on self-duality property,and then we show the convergence to the invariant probability measure vh holds for a broad class of initial distributions.Second,if (a(i,j))i,j∈s is transient and symmetric,and the diffusion parameter c remains below a threshold,we are able to determine the set of extremal invariant probability measures with finite second moment.Finally,in the case that the transition kernel (a(i,j))i,j∈s is doubly stochastic and satisfies Case Ⅰ (see Case Ⅰ in [Shiga,T.:An interacting system in population genetics.J.Math.Kyoto Univ.,20,213-242 (1980)]),we show that this parabolic Anderson model locally dies out independent of the diffusion parameter c.

  20. Chiral Condensate and Mott-Anderson Freeze-Out

    International Nuclear Information System (INIS)

    We present the idea of a Mott-Anderson freeze-out that suggests a key role of the localization of the hadron wave functions when traversing the hadronization transition. The extension of hadron wave functions in dense matter is governed by the behavior of the chiral quark condensate such that its melting at finite temperatures and chemical potentials entails an increase of the size of hadrons and thus their geometrical strong interaction cross sections. It is demonstrated within a schematic resonance gas model, that a kinetic freeze-out condition reveals a correlation with the reduction of the chiral condensate in the phase diagram up to 50% of its vacuum value. Generalizing the description of the chiral condensate by taking into account a full hadron resonance gas such correlation gets distorted. We discuss, that this may be due to our approximations in calculating the chiral condensate which disregard both, in-medium effects on hadron masses and hadron-hadron interactions. The latter, in particular due to quark exchange reactions, could lead to a delocalization of the hadron wave functions in accordance with the picture of a Mott-Anderson transition. (author)

  1. Price-Anderson Act - the third decade. Report to Congress

    International Nuclear Information System (INIS)

    Subsection 170p. of the Atomic Energy Act of 1954, as amended, requires that the Commission submit to the Congress by August 1, 1983, a detailed report on the need for continuation or modification of Section 170 of the Act, the Price-Anderson provisions. The report is divided into four sections with detailed subject reports appended to the main report. Sections I through III include an examination of issues that the Commission was required by statute to study (i.e., condition of the nuclear industry, state of knowledge of nuclear safety, and availability of private insurance), and discussion of other issues of interest and importance to the Congress and to the public. The subjects covered are as follows: (1) overview of the Price-Anderson system; (2) the state of knowledge of nuclear safety; (3) availability of private insurance; (4) conditions of the nuclear industry; (5) causality and proof of damages; (6) limitation of liability and subsidy; and (7) a proposal that would provide for removal of the limitation of liability but with limited annual liability payments. Section IV of the report contains conclusions and recommendations. Section V contains a bibliography

  2. Integrals of motion for one-dimensional Anderson localized systems

    Science.gov (United States)

    Modak, Ranjan; Mukerjee, Subroto; Yuzbashyan, Emil A.; Shastry, B. Sriram

    2016-03-01

    Anderson localization is known to be inevitable in one-dimension for generic disordered models. Since localization leads to Poissonian energy level statistics, we ask if localized systems possess ‘additional’ integrals of motion as well, so as to enhance the analogy with quantum integrable systems. We answer this in the affirmative in the present work. We construct a set of nontrivial integrals of motion for Anderson localized models, in terms of the original creation and annihilation operators. These are found as a power series in the hopping parameter. The recently found Type-1 Hamiltonians, which are known to be quantum integrable in a precise sense, motivate our construction. We note that these models can be viewed as disordered electron models with infinite-range hopping, where a similar series truncates at the linear order. We show that despite the infinite range hopping, all states but one are localized. We also study the conservation laws for the disorder free Aubry-Andre model, where the states are either localized or extended, depending on the strength of a coupling constant. We formulate a specific procedure for averaging over disorder, in order to examine the convergence of the power series. Using this procedure in the Aubry-Andre model, we show that integrals of motion given by our construction are well-defined in localized phase, but not so in the extended phase. Finally, we also obtain the integrals of motion for a model with interactions to lowest order in the interaction.

  3. Mesoscopic Anderson Box: Connecting Weak to Strong Coupling

    Science.gov (United States)

    Liu, Dong E.; Burdin, Sebastien; Baranger, Harold U.; Ullmo, Denis

    2011-03-01

    Both the weakly coupled and strong coupling Anderson impurity problem are characterized by a Fermi-liquid theory with weakly interacting quasiparticles. In an Anderson box, mesoscopic fluctuations of the effective single particle properties will be large. We study how the statistical fluctuations in these two problems are connected. We use random matrix theory and the slave boson mean field approximation (SBMF, at low temperature) to address this question, obtaining the following results. First, for a resonant level model such as results from the SBMF approximation, we find the joint distribution of energy levels with and without the resonant level present. Second, if only energy levels within the Kondo resonance are considered, the distribution of perturbed levels collapse to one universal form for both GOE and GUE for all values of the coupling V. Finally, a purely Fermi liquid method is developed for calculating the perturbed levels within the Kondo resonance. Comparing the levels that result to those of the SBMF, we find remarkable agreement.

  4. Microscopic foundations of the vector meson dominance model and the analysis of ρ-ω mixing

    International Nuclear Information System (INIS)

    We use a momentum-space analysis of a generalized Nambu endash Jona-Lasinio (NJL) model to provide a microscopic foundation for the vector-meson-dominance model. (In our model the photon interacts with the constituent quarks rather than with the hadrons.) A novel feature of our model is the introduction of q2-dependent meson decay constants, gρ(q2) and gω(q2), as well as q2-dependent meson-meson coupling constants, such as gρππ(q2). We discuss the values of gρ(q2), gω(q2), and gρππ(q2) obtained using our generalized NJL model, considering different choices for the parameters of the model. We also provide a quark-based description of ρ-ω mixing including the effects of direct ω→π++π- decay. The definition of momentum-dependent meson decay constants allows us to introduce current correlation functions for the ρ and ω mesons into the analysis in an unambiguous manner, when we start with an analysis of hadronic current correlators that are expressed in terms of quark fields. A good fit is obtained for the pion form factor in the region where ρ-ω mixing is important. copyright 1997 The American Physical Society

  5. Vector meson mixing and charge symmetry violation

    International Nuclear Information System (INIS)

    We discuss the consistency of the traditional vector meson dominance (VMD) model for photons coupling to matter with the vanishing of vector meson-meson- and meson-photon mixing self-energies at q2 = O. This vanishing of vector mixing has been demonstrated in the context of rho-omega mixing for a large class of effective theories. As a further constraint on these models, we here apply them to a study of photon-meson mixing and VMD. We compare the predicted momentum dependence of two models with that extracted experimentally. We find that one model produces a momentum-dependence which is consistent with the data, while the other does not. Hence we conclude that comparison with VMD phenomenology provides a powerful constraint on such models. (author). 34 refs., 1 fig

  6. D-meson diffusion in hadronic matter

    International Nuclear Information System (INIS)

    We present effective-field-theory results with unitarized interactions on the D-meson transport coefficients in a gas populated by light mesons and baryons at finite temperature and baryochemical potential. The Fokker-Planck equation is used to compute the drag force, the relaxation time and the diffusion coefficients of D mesons for collisions at FAIR. At finite baryochemical potential, the combined effect of net baryonic density and sizable meson-baryon interaction makes the D mesons to relax more efficiently than in the μB = 0 case. We also describe the connection with the quark-gluon plasma phase in adiabatic trajectories on the phase diagram at both zero and finite baryochemical potential.

  7. Light Vector Mesons in the Nuclear Medium

    Energy Technology Data Exchange (ETDEWEB)

    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

  8. Strange and charm mesons at FAIR

    CERN Document Server

    Tolos, L; Gamermann, D; Garcia-Recio, C; Molina, R; Nieves, J; Oset, E; Ramos, A

    2009-01-01

    We study the properties of strange and charm mesons in hot and dense matter within a self-consistent coupled-channel approach for the experimental conditions of density and temperature expected for the CBM experiment at FAIR/GSI. The in-medium solution at finite temperature accounts for Pauli blocking effects, mean-field binding of all the baryons involved, and meson self-energies. We analyze the behaviour in this hot and dense environment of dynamically-generated baryonic resonances together with the evolution with density and temperature of the strange and open-charm meson spectral functions. We test the spectral functions for strange mesons using energy-weighted sum rules and finally discuss the implications of the properties of charm mesons on the D_{s0}(2317) and the predicted X(3700) scalar resonances.

  9. Fermi-liquid theory for the single-impurity Anderson model

    Science.gov (United States)

    Mora, Christophe; Moca, Cǎtǎlin Paşcu; von Delft, Jan; Zaránd, Gergely

    2015-08-01

    We generalize Nozières' Fermi-liquid theory for the low-energy behavior of the Kondo model to that of the single-impurity Anderson model. In addition to the electrons' phase shift at the Fermi energy, the low-energy Fermi-liquid theory is characterized by four Fermi-liquid parameters: the two given by Nozières that enter to first order in the excitation energy, and two additional ones that enter to second order and are needed away from particle-hole symmetry. We express all four parameters in terms of zero-temperature physical observables, namely the local charge and spin susceptibilities and their derivatives with respect to the local level position. We determine these in terms of the bare parameters of the Anderson model using Bethe ansatz and numerical renormalization group (NRG) calculations. Our low-energy Fermi-liquid theory applies throughout the crossover from the strong-coupling Kondo regime via the mixed-valence regime to the empty-orbital regime. From the Fermi-liquid theory, we determine the conductance through a quantum dot symmetrically coupled to two leads in the regime of small magnetic field, low temperature, and small bias voltage, and compute the coefficients of the ˜B2 , ˜T2 , and ˜V2 terms exactly in terms of the Fermi-liquid parameters. The coefficients of T2, V2, and B2 are found to change sign during the Kondo to empty-orbital crossover. The crossover becomes universal in the limit that the local interaction is much larger than the level width. For completeness, we also compute the shot noise and discuss the resulting Fano factor.

  10. The Viscosity of Meson Matter

    CERN Document Server

    Dobado, A; Dobado, Antonio; Llanes-Estrada, Felipe J.

    2003-01-01

    We report a calculation of the shear viscosity in a relativistic multicomponent meson gas as a function of temperature and chemical potentials. We approximately solve the Uehling-Uhlenbeck transport equation of kinetic theory, appropriate for a boson gas, with relativistic kinematics. Since at low temperatures the gas can be taken as mostly composed of pions, with a fraction of kaons and etas, we explore the region where binary elastic collisions with at least one pion are the dominant scattering processes. Our input meson scattering phase shifts are fits to the experimental data obtained from chiral perturbation theory and the Inverse Amplitude Method. Our results take the correct non-relativistic limit (viscosity proportional to the square root of the temperature), show a viscosity of order the cubed of the pion mass up to temperatures somewhat below that mass, and then a large increase due to kaons and etas. Our approximation may break down at even higher temperatures, where the viscosity follows a tempera...

  11. Mesons in relativistic quark model

    International Nuclear Information System (INIS)

    In the relativistic quark model formulated in the infinite momentum frame a self-consistent description has been obtained for a pion, ω- and ρ-mesons, K- and K*-mesons. The role of the relativistic effects in the description of radiative, leptonic and semileptonic decays of heavy quarkonia is studied. The relativistic effects are shown to lead to noticeable suppression of the ψ → ηcγ decay width predicted in nonrelativistic approximation; however the discrepancy with the experimental data still remains. Predictions are obtained for amplitudes of D → μν, Ds → μν, B → μν, D → πeν and D → Keν decays. The relativistic effects are shown to lead to strong supperssion of coupling constants of D → μν, Ds → μν, B → μν decays. The prediction obtained for the coupling constant FD = 230-270 MeV is close to the boundary of available experimental restriction. 46 refs.; 2 figs.; 5 tabs

  12. Pseudocalar meson and vector meson interactions and dynamically generated axial-vector mesons

    OpenAIRE

    Zhou, Yu; Ren, Xiu-Lei; Chen, Hua-Xing; Geng, Li-Sheng

    2014-01-01

    The axial-vector mesons $a_1(1260)$, $b_1(1235)$, $f_1(1285)$, $h_1(1170)$, $h_1(1380)$, and $K_1(1270)$ are dynamically generated in the unitized chiral perturbation theory. Such a picture has been tested extensively in the past few years. In this work, we calculate the interaction kernel up to $\\mathcal{O}(p^2)$ and study the impact on the dynamically generated axial-vector states. In anticipation of future lattice QCD simulations, we calculate the scattering lengths and the pole positions ...

  13. D-meson production by muons in the COMPASS experiment at CERN

    Energy Technology Data Exchange (ETDEWEB)

    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

  14. Undergraduate participation in the ACU particle physics program

    International Nuclear Information System (INIS)

    Undergraduate students from ACU have played important roles in particle physics research since 1979. Most of the involvement has centered around the pion-nucleon program at the Clinton P. Anderson Meson Factory (LAMPF) at Los Alamos, NM. Other laboratories where students have participated have been Brookhaven, Fermilab, and the Petersburg Nuclear Physics Institute (Russia). The world's first complete sets of data in pion-nucleon scattering in the resonance region have been obtained. These measurements consisted of differential cross sections and analyzing power measurements for π+p → π+p, π-p →π0n and the spin rotation parameters (A ampersand R) for the first two reactions. Recent measurements have concentrated on detecting neutral-particle final states in pion-nucleon interactions, including measurements at the world's lowest energies for π-p → π0n (charge exchange scattering) and eta production (π-p → ηn). An overview of the experimental program and significant results will be presented. Insights will be discussed on the involvement of undergraduates in this type of research, based on fifteen years of experience

  15. Possible Anderson transition below two dimensions in disordered systems of noninteracting electrons

    OpenAIRE

    Asada, Yoichi; Slevin, Keith; Ohtsuki, Tomi

    2005-01-01

    We investigate the possibility of an Anderson transition below two dimensions in disordered systems of non-interacting electrons with symplectic symmetry. Numerical analysis of energy level statistics and conductance statistics on Sierpinski carpets with spin-orbit coupling indicates the occurrence of an Anderson transition below two dimensions.

  16. Dimensional Dependence of Critical Exponent of the Anderson Transition in the Orthogonal Universality Class

    OpenAIRE

    Ueoka, Yoshiki; Slevin, Keith

    2014-01-01

    We report improved numerical estimates of the critical exponent of the Anderson transition in Anderson's model of localization in $d=4$ and $d=5$ dimensions. We also report a new Borel-Pad\\'e analysis of existing $\\epsilon$ expansion results that incorporates the asymptotic behaviour for $d\\to \\infty$ and gives better agreement with available numerical results.

  17. All-solid-state cavity QED using Anderson-localized modes in disordered photonic crystal waveguides

    DEFF Research Database (Denmark)

    Lodahl, Peter; Sapienza, Luca; Nielsen, Henri Thyrrestrup;

    2010-01-01

    We employ Anderson-localized modes in deliberately disordered photonic crystal waveguides to confine light and enhance the interaction with matter. A 15-fold enhancement of the decay rate of a single quantum dot is observed meaning that 94% of the emitted single photons are coupled to an Anderson...

  18. Mesons from global Anti-de Sitter space

    CERN Document Server

    Erdmenger, Johanna

    2010-01-01

    In the context of gauge/gravity duality, we study both probe D7-- and probe D5--branes in global Anti-de Sitter space. The dual field theory is N=4 theory on R x S^3 with added flavour. The branes undergo a geometrical phase transition in this geometry as function of the bare quark mass m_q in units of 1/R with R the S^3 radius. The meson spectra are obtained from fluctuations of the brane probes. First, we study them numerically for finite quark mass through the phase transition. Moreover, at zero quark mass we calculate the meson spectra analytically both in supergravity and in free field theory on R x S^3 and find that the results match: For the chiral primaries, the lowest level is given by the zero point energy or by the scaling dimension of the operator corresponding to the fluctuations, respectively. The higher levels are equidistant. Similar results apply to the descendents. Our results confirm the physical interpretation that the mesons cannot pair-produce any further when their zero-point energy exc...

  19. Strong Couplings of Three Mesons with Charm(ing) Involvement

    CERN Document Server

    Lucha, Wolfgang; Sazdjian, Hagop; Simula, Silvano

    2016-01-01

    We determine the strong couplings of three mesons that involve, at least, one $\\eta_c$ or $J/\\psi$ meson, within the framework of a constituent-quark model by means of relativistic dispersion formulations. For strong couplings of $J/\\psi$ mesons to two charmed mesons, our approach leads to predictions roughly twice as large as those arising from QCD sum rules.

  20. The (di)muon physics in the ALICE experiment at the LHC: light vector meson analysis (ρ, ω, φ) in pp collisions [√(s)=7 TeV], Pb-Pb collisions [√(sNN)=2.76 TeV] and study of a new silicon tracker in the muon spectrometer acceptance

    International Nuclear Information System (INIS)

    ALICE experiment at LHC studies the Quark Gluon Plasma (QGP), a particular state of matter where quarks and gluons are deconfined. A probe to explore this state is the study of several resonances (ρ, ω, φ, J/ψ and Υ) through their dimuon decay channel, with a muon spectrometer covering pseudo-rapidity -4 NN)=2.76 TeV. Light vector mesons are powerful tools to probe the QGP due to their short lifetime and their dimuon decay channel. Indeed, leptons have negligible final state interactions. Production rates and spectral functions of those mesons are modified by the hot hadronic and QGP medium. Chiral symmetry restoration study is done thanks to the study of ρ spectral function. Strangeness enhancement is accessed via the ratio of φ over ρ + ω yields as a function of the centrality of the collision. In pp analysis, the emphasis is on background understanding and on first physics results such as φ yield over ρ + ω yield as a function of pT, and pT distributions of φ and ρ + ω. Cross sections and pT-differential cross sections of light mesons will also be shown. The Pb-Pb analysis and its prospects will be presented. The second part of the thesis concerns ALICE upgrade plans of year 2017. A feasibility study for a Muon Forward Tracker (MFT) in Silicon pixels located upstream of the hadronic absorber in the spectrometer acceptance was performed. This upgrade is mainly motivated by the improvement of the dimuon invariant mass resolution and secondary vertex measurement. This gives access to open charm and beauty direct study in single muon channel. Prompt J/ψ can also be distinguished from B feed-down J/ψ, allowing a better study of a QGP signature: the 'J/ψ suppression' in ultra-relativistic heavy ion collisions. MFT performances on those different topics were established in simulations. The track matching algorithm to match MFT tracks with spectrometer tracks (a crucial step for the feasibility of the project) and its results are presented. (author)

  1. Distortion of the HBT images by meson clouds

    CERN Document Server

    Hattori, K

    2009-01-01

    We study the effects of mesonic final state interactions on the Hanbury Brown and Twiss (HBT) intensity interferometry for mesons in ultra-relativistic heavy ion collisions. Modification of the one-body amplitude of emitted mesons while going through a cloud of other mesons is estimated in the semiclassical approximation with a mesonic optical potential which incorporates both coherent forward scattering with other mesons and the absorption due to the incoherent scattering in the meson clouds. We show how these effects results in the distortion of the HBT images.

  2. Exclusive φ meson production in HERMES

    Energy Technology Data Exchange (ETDEWEB)

    Golembiovskaya, Mayya

    2014-03-15

    In the present work exclusive φ meson leptoproduction at HERMES experiment in DESY was studied using the data collected at HERA accelerator in the period from 1998 till 2000 and from 2006 till 2007 years. In the analysis unpolarized and longitudinally polarized hydrogen and deuteron targets were used, the beam consisted of longitudinally polarized leptons. Via measurement of the angular and momentum distribution of the φ meson decay products 23 spin density matrix elements (SDMEs) for the φ meson were obtained. The number of SDMEs was defined by the experiment conditions, e.g. by the beam and target polarization directions. For the mentioned time period φ meson SDMEs were defined at HERMES for the first time. The quantities U{sub 1}, U{sub 2} and U{sub 3} which can be used to check presence of unnatural parity exchange (UPE) mechanism in phi meson production were calculated from SDMEs. All the results were obtained in 3 kinematic bins of Q{sup 2}, 4 kinematic bins of t' and for the integrated kinematics. No statistically significant difference between the results for hydrogen and deuteron targets was observed. The UPE quantities were found to be zero within 2 σ for the integrated kinematics, indicating negligible contribution of UPE for the φ meson production which is in agreement with theory predictions. The test of s-channel helicity conservation hypothesis via comparison of corresponding SDME values showed helicity conservation for the φ meson production.

  3. Exclusive φ meson production in HERMES

    International Nuclear Information System (INIS)

    In the present work exclusive φ meson leptoproduction at HERMES experiment in DESY was studied using the data collected at HERA accelerator in the period from 1998 till 2000 and from 2006 till 2007 years. In the analysis unpolarized and longitudinally polarized hydrogen and deuteron targets were used, the beam consisted of longitudinally polarized leptons. Via measurement of the angular and momentum distribution of the φ meson decay products 23 spin density matrix elements (SDMEs) for the φ meson were obtained. The number of SDMEs was defined by the experiment conditions, e.g. by the beam and target polarization directions. For the mentioned time period φ meson SDMEs were defined at HERMES for the first time. The quantities U1, U2 and U3 which can be used to check presence of unnatural parity exchange (UPE) mechanism in phi meson production were calculated from SDMEs. All the results were obtained in 3 kinematic bins of Q2, 4 kinematic bins of t' and for the integrated kinematics. No statistically significant difference between the results for hydrogen and deuteron targets was observed. The UPE quantities were found to be zero within 2 σ for the integrated kinematics, indicating negligible contribution of UPE for the φ meson production which is in agreement with theory predictions. The test of s-channel helicity conservation hypothesis via comparison of corresponding SDME values showed helicity conservation for the φ meson production.

  4. GlueX: Meson Spectroscopy in Photoproduction

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Carlos [Norfolk State University, JLAB; Smith, Elton S. [JLAB

    2014-03-01

    The goal of the GlueX experiment \\cite{gluex} is to provide crucial data to help understand the soft gluonic fields responsible for binding quarks in hadrons. Hybrid mesons, and in particular exotic hybrid mesons, provide the ideal laboratory for testing QCD in the confinement regime since these mesons explicitly manifest the gluonic degrees of freedom. Photoproduction is expected to be effective in producing exotic hybrids but there is little data on the photoproduction of light mesons. GlueX will use the new 12-GeV electron beam at Jefferson Lab to produce a 9-GeV beam of linearly polarized photons using the technique of coherent bremsstrahlung. A solenoid-based hermetic detector is under construction, which will be used to collect data on meson production and decays. These data will also be used to study the spectrum of conventional mesons, including the poorly understood excited vector mesons. This talk will give an update on the experiment as well as describe theoretical developments \\cite{Dudek:2011bn} to help understand how these data can provide insights into the fundamental theory of strong interactions.

  5. Neutral $B$ meson mixings and $B$ meson decay constants with static heavy and domain-wall light quarks

    CERN Document Server

    Aoki, Yasumichi; Izubuchi, Taku; Lehner, Christoph; Soni, Amarjit

    2014-01-01

    Neutral $B$ meson mixing matrix elements and $B$ meson decay constants are calculated. Static approximation is used for $b$ quark and domain-wall fermion formalism is employed for light quarks. The calculations are carried out on $2+1$ flavor dynamical ensembles generated by RBC/UKQCD Collaborations with lattice spacings $0.086$fm ($a^{-1}\\sim 2.3$GeV) and $0.11$fm ($1.7$GeV), and a fixed physical spatial volume of about $(2.7{\\rm fm})^3$. In the static quark action, link-smearings are used to improve the signal-to-noise ratio. We employ two kinds of link-smearings, HYP1 and HYP2, and their results are combined in taking the continuum limit. For the matching between the lattice and the continuum theory, one-loop perturbative $O(a)$ improvements are made to reduce discretization errors. As the most important quantity of this work, we obtain SU(3) breaking ratio $\\xi=1.208(60)$, where the error includes statistical and systematic one. We also find other neutral $B$ meson mixing quantities $f_B\\sqrt{\\hat{B}_B}=2...

  6. Anderson localisation of visible light on a nanophotonic chip

    CERN Document Server

    Crane, Tom; Sapienza, Luca

    2016-01-01

    Controlling the propagation of visible light on a chip is of tremendous interest in research areas such as energy harvesting, imaging, sensing and biology. Technological advances allow us to control light at the nanoscale and to strongly enhance the light-matter interaction in highly engineered devices. However, compared to state-of-the-art two-dimensional optical cavities operating at longer wavelengths, the quality factor of on-chip visible light confinement is several orders of magnitude lower. Our approach makes use of fabrication imperfections to trap light: we demonstrate, for the first time, Anderson localisation of visible light on a chip. Remarkably, compared to quality factors of engineered cavities, disorder-induced localisation proves to be more efficient in trapping light than highly engineered devices, thus reversing the trend observed so far. We measure light-confinement quality factors as high as 7600 and, by implementing a sensitive imaging technique, we directly visualise the localised modes...

  7. Anderson localization in metamaterials and other complex media

    CERN Document Server

    Gredeskul, Sergey A; Asatrian, Ara A; Bliokh, Konstantin Y; Bliokh, Yuri P; Freilikher, Valentin D; Shadrivov, Ilya V

    2012-01-01

    We review some recent (mostly ours) results on the Anderson localization of light and electron waves in complex disordered systems, including: (i) left-handed metamaterials, (ii) magneto-active optical structures, (iii) graphene superlattices, and (iv) nonlinear dielectric media. First, we demonstrate that left-handed metamaterials can significantly suppress localization of light and lead to an anomalously enhanced transmission. This suppression is essential at the long-wavelength limit in the case of normal incidence, at specific angles of oblique incidence (Brewster anomaly), and in the vicinity of the zero-epsilon or zero-mu frequencies for dispersive metamaterials. Remarkably, in disordered samples comprised of alternating normal and left-handed metamaterials, the reciprocal Lyapunov exponent and reciprocal transmittance increment can differ from each other. Second, we study magneto-active multilayered structures, which exhibit nonreciprocal localization of light depending on the direction of propagation ...

  8. Defect-controlled Anderson localization of light in photonic lattices

    International Nuclear Information System (INIS)

    The transverse localization of light in a disordered photonic lattice with a central defect is analyzed numerically. The effect of different input beam widths on various regimes of Anderson localization is investigated. The inclusion of a defect enhances the localization of both narrow and broad beams, as compared to the lattice with no defect. But, in the case of a broad beam a higher disorder level is needed to reach the same localization as for a narrow input beam. It is also investigated how the transverse localization of light in such geometries depends on both the strength of disorder and the strength of nonlinearity in the system. While in the linear regime the localization is most pronounced in the lattice with the defect, in the nonlinear regime this is not the case. (paper)

  9. Lifshitz transitions in magnetic phases of the periodic Anderson model

    International Nuclear Information System (INIS)

    We investigate the reconstruction of a Fermi surface, which is called a Lifshitz transition, in magnetically ordered phases of the periodic Anderson model on a square lattice with a finite Coulomb interaction between f electrons. We apply the variational Monte Carlo method to the model by using the Gutzwiller wavefunctions for the paramagnetic, antiferromagnetic, ferromagnetic, and charge-density-wave states. We find that an antiferromagnetic phase is realized around half-filling and a ferromagnetic phase is realized when the system is far away from half-filling. In both magnetic phases, Lifshitz transitions take place. By analyzing the electronic states, we conclude that the Lifshitz transitions to large ordered-moment states can be regarded as itinerant-localized transitions of the f electrons. (author)

  10. Unconstitutionality of Section 170 (e) of the price Anderson Act

    International Nuclear Information System (INIS)

    Several environmental protection groups in the State of North Carolina have recently contested the conformity with the United States Constitution of Section 170 (e) of the Atomic Energy Act (Price-Anderson Act). The court seized of the question (the United States District Court for the western district of North Carolina, Charlotte Division) held in March 1977 that this Section and the other provisions of the Atomic Energy Act concerning implementation of the $560 million limitation of liability for nuclear damage were unconstitutional and unenforceable insofar as they applied to nuclear incidents occurring inside the United States. The defendants, the former United States Atomic Energy Commission and its then Commissioners as well as the Duke Power Company (the local electricity company) will appeal this decision. The note on case law analyses the arguments retained by the court. (NEA)

  11. Price-Anderson Nuclear Safety Enforcement Program. 1997 annual report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This report summarizes activities in the Department of Energy's Price-Anderson Amendments Act (PAAA) Enforcement Program in calendar year 1997 and highlights improvements planned for 1998. The DOE Enforcement Program involves the Office of Enforcement and Investigation in the DOE Headquarters Office of Environment, Safety and Health, as well as numerous PAAA Coordinators and technical advisors in DOE Field and Program Offices. The DOE Enforcement Program issued 13 Notices of Violation (NOV`s) in 1997 for cases involving significant or potentially significant nuclear safety violations. Six of these included civil penalties totaling $440,000. Highlights of these actions include: (1) Brookhaven National Laboratory Radiological Control Violations / Associated Universities, Inc.; (2) Bioassay Program Violations at Mound / EG and G, Inc.; (3) Savannah River Crane Operator Uptake / Westinghouse Savannah River Company; (4) Waste Calciner Worker Uptake / Lockheed-Martin Idaho Technologies Company; and (5) Reactor Scram and Records Destruction at Sandia / Sandia Corporation (Lockheed-Martin).

  12. Price-Anderson Nuclear Safety Enforcement Program. 1997 annual report

    International Nuclear Information System (INIS)

    This report summarizes activities in the Department of Energy's Price-Anderson Amendments Act (PAAA) Enforcement Program in calendar year 1997 and highlights improvements planned for 1998. The DOE Enforcement Program involves the Office of Enforcement and Investigation in the DOE Headquarters Office of Environment, Safety and Health, as well as numerous PAAA Coordinators and technical advisors in DOE Field and Program Offices. The DOE Enforcement Program issued 13 Notices of Violation (NOV's) in 1997 for cases involving significant or potentially significant nuclear safety violations. Six of these included civil penalties totaling $440,000. Highlights of these actions include: (1) Brookhaven National Laboratory Radiological Control Violations / Associated Universities, Inc.; (2) Bioassay Program Violations at Mound / EG ampersand G, Inc.; (3) Savannah River Crane Operator Uptake / Westinghouse Savannah River Company; (4) Waste Calciner Worker Uptake / Lockheed-Martin Idaho Technologies Company; and (5) Reactor Scram and Records Destruction at Sandia / Sandia Corporation (Lockheed-Martin). Sandia / Sandia Corporation (Lockheed-Martin)

  13. Quasiparticle many-body dynamics of the Anderson model

    International Nuclear Information System (INIS)

    The paper addresses the many-body quasiparticle dynamics of the Anderson impurity model at finite temperatures in the framework of the equation-of-motion method. We find a new exact identity relating the one-particle and many-particle Green's Functions. Using this identity we present a consistent and general scheme for a construction of generalised mean fields (elastic scattering corrections) and self-energy (inelastic scattering) in terms of the Dyson equation. A new approach for the complex expansion for the single-particle propagator in terms of the Coulomb repulsion U and hybridization V is proposed. Using the exact identity, the essentially new many-body dynamical solution of SIAM has been derived. This approach offers a new way for the systematic construction of the approximative interpolating dynamical solutions of the strongly correlated electron systems. 47 refs

  14. The parabolic Anderson model random walk in random potential

    CERN Document Server

    König, Wolfgang

    2016-01-01

    This is a comprehensive survey on the research on the parabolic Anderson model – the heat equation with random potential or the random walk in random potential – of the years 1990 – 2015. The investigation of this model requires a combination of tools from probability (large deviations, extreme-value theory, e.g.) and analysis (spectral theory for the Laplace operator with potential, variational analysis, e.g.). We explain the background, the applications, the questions and the connections with other models and formulate the most relevant results on the long-time behavior of the solution, like quenched and annealed asymptotics for the total mass, intermittency, confinement and concentration properties and mass flow. Furthermore, we explain the most successful proof methods and give a list of open research problems. Proofs are not detailed, but concisely outlined and commented; the formulations of some theorems are slightly simplified for better comprehension.

  15. Atomic Bose and Anderson Glasses in Optical Lattices

    Science.gov (United States)

    Damski, B.; Zakrzewski, J.; Santos, L.; Zoller, P.; Lewenstein, M.

    2003-08-01

    An ultracold atomic Bose gas in an optical lattice is shown to provide an ideal system for the controlled analysis of disordered Bose lattice gases. This goal may be easily achieved under the current experimental conditions by introducing a pseudorandom potential created by a second additional lattice or, alternatively, by placing a speckle pattern on the main lattice. We show that, for a noncommensurable filling factor, in the strong-interaction limit, a controlled growing of the disorder drives a dynamical transition from superfluid to Bose-glass phase. Similarly, in the weak interaction limit, a dynamical transition from superfluid to Anderson-glass phase may be observed. In both regimes, we show that even very low-intensity disorder-inducing lasers cause large modifications of the superfluid fraction of the system.

  16. The contribution of multi-channel pion-pion scattering to the final states of Upsilon-meson family decays

    Czech Academy of Sciences Publication Activity Database

    Surovtsev, Yu .S.; Bydžovský, Petr; Gutsche, T.; Kaminski, R.; Lyubovitskij, V. E.; Nagy, M.

    Vol. 81. Les Ulis : EDP Sciences, 2014, 05028. ISSN 2100-014X. [13th International Workshop on Production, Properties and Interaction of Mesons (MESON 2014). Krakow (PL), 29.05.2014-03.06.2014] R&D Projects: GA MŠk LG14004; GA ČR(CZ) GAP203/12/2126 Institutional support: RVO:61389005 Keywords : scattering * pion-pion * multi-channel Subject RIV: BE - Theoretical Physics

  17. Search for radiative B meson decays

    International Nuclear Information System (INIS)

    The Crystal Ball detector at the ε+ε- storage ring DORIS-II has been used to search for radiative B meson decays, especially of the type b→sγ. No mono-energetic γ-lines have been found in the inclusive photon spectrum from Υ(4S) decays, and upper limits are obtained for radiative decays of B mesons to various strange mesons and to the D*. Integrating the photon spectrum over the corresponding energy range, we find BR(B→γX)-3 at 90% confidence level for the mass range 892 MeV≤MX≤2045 MeV. (orig.)

  18. Measurement of the B0-meson lifetime

    International Nuclear Information System (INIS)

    We report a measurement of the lifetime of the B0 meson based upon 29-GeV e+e- annihilation data taken with the Mark II detector at the SLAC storage ring PEP. The B0 mesons are tagged by their decays into D*-e+ν and D*-μ+ν, where the D*- is tagged by its decay into π-bar D0. We reconstruct the decay vertices of 15 B0-meson candidates and measure the B0 lifetime to be 1.20+0.52-0.36+0.160.14 psec

  19. Bottom-strange mesons in hyperonic matter

    OpenAIRE

    Pathak, Divakar; Mishra, Amruta

    2014-01-01

    The in-medium behavior of bottom-strange pseudoscalar mesons in hot, isospin asymmetric and dense hadronic environment is studied using a chiral effective model. The same was recently generalized to the heavy quark sector and employed to study the behavior of open-charm and open-bottom mesons. The heavy quark (anti-quark) is treated as frozen and all medium modifications of these bottom-strange mesons are due to their strange anti-quark (quark) content. We observe a pronounced dependence of t...

  20. Development of the M. D. Anderson Cancer Center Gynecologic Applicators for the Treatment of Cervical Cancer: Historical Analysis

    International Nuclear Information System (INIS)

    Purpose: To provide historical background on the development and initial studies of the gynecological (gyn) applicators developed by Dr. Gilbert H. Fletcher, a radiation oncologist and chairperson from 1948 to 1981 of the department at the M.D. Anderson Hospital (MDAH) for Cancer Research in Houston, TX, and to acknowledge the previously unrecognized contribution that Dr. Leonard G. Grimmett, a radiation physicist and chairperson from 1949 to 1951 of the physics department at MDAH, made to the development of the gynecological applicators. Methods and Materials: We reviewed archival materials from the Historical Resource Center and from the Department of Radiation Physics at University of Texas M. D. Anderson Cancer Center, as well as contemporary published papers, to trace the history of the applicators. Conclusions: Dr. Fletcher’s work was influenced by the work on gynecologic applicators in the 1940s in Europe, especially work done at the Royal Cancer Hospital in London. Those efforts influenced not only Dr. Fletcher’s approach to the design of the applicators but also the methods used to perform in vivo measurements and determine the dose distribution. Much of the initial development of the dosimetry techniques and measurements at MDAH were carried out by Dr. Grimmett.

  1. Weak decays of the Bc meson to Bs and B mesons in the relativistic quark model

    International Nuclear Information System (INIS)

    Semileptonic and non-leptonic decays of the Bc meson to Bs and B mesons, caused by the c→s,d quark transitions, are studied in the framework of the relativistic quark model. The heavy quark expansion in inverse powers of the active c and spectator anti b quark is used to simplify calculations while the final s and d quarks in the Bs and B mesons are treated relativistically. The decay form factors are explicitly expressed through the overlap integrals of the meson wave functions in the whole accessible kinematical range. The obtained results are compared with the predictions of other approaches. (orig.)

  2. Tetraquarks in the 1/N expansion and meson-meson resonances

    CERN Document Server

    Maiani, L; Riquer, V.

    2016-01-01

    Diquarks are found to have the right degrees of freedom to describe the tetraquark poles in hidden-charm to open-charm meson-meson amplitudes. Compact tetraquarks result as intermediate states in non-planar diagrams of the 1/N expansion and the corresponding resonances are narrower than what estimated before. The proximity of tetraquarks to meson-thresholds has an apparent role in this analysis and, in the language of meson molecules, an halving rule in the counting of states is obtained.

  3. Modified meson-nucleus optical potentials

    CERN Document Server

    Wilkin, C

    1973-01-01

    The author argues that the energy dependence of the meson-nucleus optical potential should be treated in a more dynamical fashion. When this is done, some of the difficulties found in phenomenological applications are eliminated. (13 refs).

  4. (→ + - 0) meson photoproduction on proton

    Indian Academy of Sciences (India)

    Swapan Das

    2010-10-01

    The cross-section for the + - 0 invariant mass distribution in the $ p$ reaction in the GeV region is calculated. This reaction is assumed to proceed through the formation of the -meson in the intermediate state, because the production cross-section for this meson in the reaction in the GeV region is significant and it has a large branching ratio (88.8%) in the + − 0 channel. The cross-sections for this reaction are calculated using the energy-dependent reaction amplitude, → (0), extracted from the latest -meson photoproduction data. We use established procedure to calculate other factors, like width and propagator of the -meson, so that our calculation can provide reliable cross-section. The calculated results reproduce the measured + - 0 invariant mass distribution spectra in the reaction.

  5. Kaons in flavor tagged B meson decays

    International Nuclear Information System (INIS)

    Using the ARGUS detector at the e+e- storage ring DORIS II, measurements of multiplicities of pseudoscalar kaons, of K*(892) and of φ(1020) in B meson decays have been performed through studies of angular and charge correlations between the above particles and high momentum leptons produced in semileptonic B decays. The method has made it possible to measure the multiplicities separately for B-mesons and anti-B-mesons. The excess of like charge lepton-kaon pairs over opposite charge pairs in semileptonic decays was used for estimating the ratio of charmed decays over all decays, and thus also the fraction of charmless decays. A search for an excess of fast neutral kaons from rare B decays was also made. All the results obtained support the assumption that almost all B mesons decay through b → c transitions into charmed hadrons. (66 refs.)

  6. Photo and electroproduction of heavy mesons

    International Nuclear Information System (INIS)

    This report reviews first the η0 photoproduction then the photoproduction vector mesons and presents some results. Finally, some notes on the experimental devices which should have to be developed to undertake this study are given

  7. Soft and Hard Scale QCD Dynamics in Mesons

    International Nuclear Information System (INIS)

    Using a ladder-rainbow kernel previously established for light quark hadron physics, we explore the extension to masses and electroweak decay constants of ground state pseudoscalar and vector quarkonia and heavy-light mesons in the c- and b-quark regions. We make a systematic study of the effectiveness of a constituent mass concept as a replacement for a heavy quark dressed propagator for such states. The difference between vector and axial vector current correlators is explored within the same model to provide an estimate of the four quark chiral condensate and the leading distance scale for the onset of non-perturbative phenomena in QCD.

  8. Radiative decay modes of the D0 meson

    International Nuclear Information System (INIS)

    In this paper we describe a search for four radiative decay modes of the D0 meson: D0→φγ, D0→ωγ, D0→ bar K*γ, and D0→ρ0γ. We obtain 90% C.L. upper limits on the branching ratios of these modes of 1.9x10-4, 2.4x10-4, 7.6x10-4, and 2.4x10-4, respectively. copyright 1998 The American Physical Society

  9. Quasinormal modes and meson decay rates

    Energy Technology Data Exchange (ETDEWEB)

    Hoyos, C. [Department of Physics, University of Wales Swansea, Swansea, SA2 8PP (United Kingdom); Landsteiner, K.; Montero, S. [Instituto de Fisica Teorica, C-XVI Universidad Autonoma de Madrid, 28049 Madrid (Spain)

    2007-05-15

    We model meson melting in a hot plasma by the quasinormal modes of D7-brane fluctuations of embeddings that fall into the horizon of a black hole in Ads{sub 5} x S{sup 5} geometry. The inverse of the imaginary part of the quasinormal frequency gives the lifetime of the meson in the plasma. We briefly comment on the possible application of our model to quarkonium suppression. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  10. Quasinormal modes and meson decay rates

    International Nuclear Information System (INIS)

    We model meson melting in a hot plasma by the quasinormal modes of D7-brane fluctuations of embeddings that fall into the horizon of a black hole in Ads5 x S5 geometry. The inverse of the imaginary part of the quasinormal frequency gives the lifetime of the meson in the plasma. We briefly comment on the possible application of our model to quarkonium suppression. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  11. Meson condensation in dense matter revisited

    CERN Document Server

    Yabu, H; Kubodera, K; Yabu, Hiroyuki

    1994-01-01

    The results for meson condensation in the literature vary markedly depending on whether one uses chiral perturbation theory or the current-algebra-plus-PCAC approach. To elucidate the origin of this discrepancy, we re-examine the role of the sigma-term in meson condensation. We find that the resolution of the existing discrepancy requires a knowledge of terms in the Lagrangian that are higher order in density than hitherto considered.

  12. Rare meson decays into very light neutralinos

    CERN Document Server

    O'Leary, Ben

    2009-01-01

    Results are presented for the two-body decays of mesons into light neutralinos and from the first complete calculation of the loop-induced decays of kaons to pions plus light neutralinos and of B mesons to kaons plus light neutralinos. The branching ratios are shown to be strongly suppressed within the MSSM with minimal flavor violation, and no bounds on the neutralino mass can be inferred from experimental data, i.e. a massless neutralino is allowed.

  13. A light exotic qantiqg hermaphrodite meson

    International Nuclear Information System (INIS)

    It is suggested that qantiqg mesons may exist as low as 1Gev in mass. The exotic Jsup(PC)=1-+ multiplet will have distinctive decay modes and perhaps be relatively stable. The bag model spectrum of the lowest lying qantiqg multiplet including hyperfine splittings is computed analogously to Jaffe's (Phys. Lett.; 60B:201 (1976)) qantiqqantiq bag model multiplets. Relevance to light meson phenomenology is discussed. (author)

  14. Oscillations of neutral B mesons systems

    OpenAIRE

    Boucrot, J.

    1999-01-01

    The oscillation phenomenon in the neutral B mesons systems is now well established. The motivations and principles of the measurements are given; then the most recent results from the LEP experiments, the CDF collaboration at Fermilab and the SLD collaboration at SLAC are reviewed. The present world average of the $\\bd$ meson oscillation frequency is $\\dmd = 0.471 \\pm 0.016 \\ps$ and the lower limit on the $\\bs$ oscillation frequency is $\\dms > 12.4 \\ps at 95% CL$.

  15. Meson and baryon spectroscopy on the lattice

    Energy Technology Data Exchange (ETDEWEB)

    David Richards

    2010-12-01

    Recent progress at understanding the excited state spectrum of mesons and baryons is described. I begin by outlining the application of the variational method to compute the spectrum, and the program of anisotropic clover lattice generation designed for hadron spectroscopy. I present results for the excited meson spectrum, with continuum quantum numbers of the states clearly delineated. I conclude with recent results for the low lying baryon spectrum, and the prospects for future calculations.

  16. The interactions of heavy mesons with nuclei

    International Nuclear Information System (INIS)

    Data obtained from interactions of heavy mesons with nuclei is reviewed. Nucleon-nucleon reactions followed by p + d (or d+p) reactions and nucleon-nucleus reactions are described. A meson decay experiment is discussed. The fundamental importance of S11 (1535) in η-nucleon is stressed. The propagation of resonances through nuclear matter is considered. Improvements in this research field require the developement of a new accelerator generation

  17. Bs mesons: semileptonic and nonleptonic decays

    Directory of Open Access Journals (Sweden)

    Albertus C.

    2014-01-01

    Full Text Available In this contribution we compute some nonleptonic and semileptonic decay widths of Bs mesons, working in the context of constituent quark models [1, 2]. For the case of semileptonic decays we consider reactions leading to kaons or different Jπ Ds mesons. The study of nonleptonic decays has been done in the factorisation approximation and includes the final states enclosed in Table 2.

  18. Beautiful mesons from QCD spectral sum rules

    Energy Technology Data Exchange (ETDEWEB)

    Narison, S. (OPM, Univ. Montpellier 2, 34 (France))

    1991-08-01

    We discuss the beautiful meson from the point of view of the QCD spectral sum rules (QSSR). The bottom quark mass and the mixed light quark-gluon condensates are determined quite accurately. The decay constant f{sub B} is estimated and we present some arguments supporting this result. The decay constants and the masses of the other members of the beautiful meson family are predicted. (orig.).

  19. Light $O^{++}$ Mesons: Scalargators in Florida

    OpenAIRE

    Pennington, M. R.

    2010-01-01

    Light scalar mesons abound in hadron processes, like the alligators in the Florida Everglades. Moreover, scalars are intimately tied to the vacuum structure of QCD. They are the product of many decays. Consequently, a rich source of recent information about them has come from experiments producing heavy flavour mesons. Indeed, scalars will continue to dominate many of the processes to be studied at forthcoming facilities like BESIII in Beijing, FAIR at GSI Darmstadt and the GlueX experiment a...

  20. Meson Condensation in Dense Matter Revisited

    OpenAIRE

    Yabu, Hiroyuki; Myhrer, F.; Kubodera, K.

    1994-01-01

    The results for meson condensation in the literature vary markedly depending on whether one uses chiral perturbation theory or the current-algebra-plus-PCAC approach. To elucidate the origin of this discrepancy, we re-examine the role of the sigma-term in meson condensation. We find that the resolution of the existing discrepancy requires a knowledge of terms in the Lagrangian that are higher order in density than hitherto considered.

  1. A search for {phi} meson nucleus bound state using antiproton annihilation on nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, H., E-mail: h-ohnishi@riken.jp [RIKEN, RIKEN Nishina Center (Japan); Buehler, P.; Cargnelli, M. [Stefan-Meyer-Institut fNur subatomare Physik (Austria); Curceanu, C.; Guaraldo, C. [Laboratori Nazionali di Frascati dellf INFN (Italy); Hartmann, O. [Stefan-Meyer-Institut fNur subatomare Physik (Austria); Hicks, K. [Ohio University, Department of Physics and Astronomy (United States); Iwasaki, M. [RIKEN, RIKEN Nishina Center (Japan); Ishiwatari, T. [Stefan-Meyer-Institut fNur subatomare Physik (Austria); Kienle, P. [Technische Universiat Munchen (Germany); Marton, J. [Stefan-Meyer-Institut fuer subatomare Physik (Austria); Muto, R.; Naruki, M. [KEK (High Energy Accelerator Research Organization) (Japan); Niiyama, M. [Kyoto University, Department of Physics (Japan); Noumi, H. [Osaka University, Research Center for Nuclear Physics (Japan); Okada, S.; Vidal, A. Romero [Laboratori Nazionali di Frascati dellf INFN (Italy); Sakaguchi, A. [Osaka University, Department of Physics (Japan); Sakuma, F. [RIKEN, RIKEN Nishina Center (Japan); Sawada, S. [KEK (High Energy Accelerator Research Organization) (Japan); and others

    2012-12-15

    The mass shift of the vector mesons in nuclei is known to be a powerful tool for investigating the mechanism of generating hadron mass from the QCD vacuum. The mechanism is known to be the spontaneous breaking of chiral symmetry. In 2007, KEK-PS E325 experiment reported about 3.4 % mass reduction of the {phi} meson in medium-heavy nuclei (Cu). This result is possibly one of the indications of the partial restoration of chiral symmetry in nuclei, however, unfortunately it is hard to make strong conclusions from the data. One of the ways to conclude the strength of the {phi} meson mass shift in nuclei will be by trying to produce only slowly moving {phi} mesons where the maximum nuclear matter effect can be probed. The observed mass reduction of the {phi} meson in the nucleus can be translated as the existence of an attractive force between {phi} meson and nucleus. Thus, one of the extreme conditions that can be achieved in the laboratory is indeed the formation of a {phi}-nucleus bound state, where the {phi} meson is 'trapped' in the nucleus. The purpose of the experiment is to search for a {phi}-nucleus bound state and measure the binding energy of the system. We will demonstrate that a completely background-free missing-mass spectrum can be obtained efficiently by (p-bar, {phi}) spectroscopy together with K{sup + }{Lambda} tagging, using the primary reaction channel p-bar p {yields} {phi} {phi}. This paper gives an overview of the physics motivation and the detector concept, and explains the direction of the initial research and development effort.

  2. A search for ϕ meson nucleus bound state using antiproton annihilation on nucleus

    Science.gov (United States)

    Ohnishi, H.; Bühler, P.; Cargnelli, M.; Curceanu, C.; Guaraldo, C.; Hartmann, O.; Hicks, K.; Iwasaki, M.; Ishiwatari, T.; Kienle, P.; Marton, J.; Muto, R.; Naruki, M.; Niiyama, M.; Noumi, H.; Okada, S.; Vidal, A. Romero; Sakaguchi, A.; Sakuma, F.; Sawada, S.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Tsukada, K.; Doce, O. Vazquez; Widmann, E.; Yokkaichi, S.; Zmeskal, J.

    The mass shift of the vector mesons in nuclei is known to be a powerful tool for investigating the mechanism of generating hadron mass from the QCD vacuum. The mechanism is known to be the spontaneous breaking of chiral symmetry. In 2007, KEK-PS E325 experiment reported about 3.4 % mass reduction of the ϕ meson in medium-heavy nuclei (Cu). This result is possibly one of the indications of the partial restoration of chiral symmetry in nuclei, however, unfortunately it is hard to make strong conclusions from the data. One of the ways to conclude the strength of the ϕ meson mass shift in nuclei will be by trying to produce only slowly moving ϕ mesons where the maximum nuclear matter effect can be probed. The observed mass reduction of the ϕ meson in the nucleus can be translated as the existence of an attractive force between ϕ meson and nucleus. Thus, one of the extreme conditions that can be achieved in the laboratory is indeed the formation of a ϕ-nucleus bound state, where the ϕ meson is "trapped" in the nucleus. The purpose of the experiment is to search for a ϕ-nucleus bound state and measure the binding energy of the system. We will demonstrate that a completely background-free missing-mass spectrum can be obtained efficiently by (bar{p}, φ) spectroscopy together with K + Λ tagging, using the primary reaction channel bar{p} p rightarrow φ φ. This paper gives an overview of the physics motivation and the detector concept, and explains the direction of the initial research and development effort.

  3. The continuum limit of the $D$ meson, $D_s$ meson and charmonium spectrum from $N_f=2+1+1$ twisted mass lattice QCD

    CERN Document Server

    Cichy, Krzysztof; Wagner, Marc

    2016-01-01

    We compute masses of $D$ meson, $D_s$ meson and charmonium states using $N_f=2+1+1$ Wilson twisted mass lattice QCD. All results are extrapolated to physical light quark masses, physical strange and charm quark masses and to the continuum. Our analysis includes states with spin $J = 0,1,2$, parity $\\mathcal{P} = -,+$ and in case of charmonium also charge conjugation $\\mathcal{C} = -,+$. Computations are based on a large set of quark-antiquark meson creation operators. We investigate and quantify all sources of systematic errors, including fitting range uncertainties, finite volume effects, isospin breaking effects and the choice of the fitting ansatz for the combined chiral and continuum extrapolation such that the resulting meson masses can be compared directly and in a meaningful way to experimental results. Within combined statistical and systematic errors, which are between below two per mille and three percent, our results agree with available experimental results for most of the states. In the few cases...

  4. In-medium (K)over-bar- and eta-Meson Interactions and Bound States

    Czech Academy of Sciences Publication Activity Database

    Gal, A.; Friedman, E.; Barnea, N.; Cieplý, Aleš; Mareš, Jiří; Gazda, Daniel

    2014-01-01

    Roč. 45, č. 3 (2014), s. 673-687. ISSN 0587-4254 R&D Projects: GA ČR(CZ) GAP203/12/2126 Institutional support: RVO:61389005 Keywords : meson-baryon * subthreshold energies * n amplitudes Subject RIV: BE - Theoretical Physics Impact factor: 0.850, year: 2014

  5. Calculating the two-pion decay and mixing of neutral K mesons

    CERN Document Server

    Christ, Norman H

    2013-01-01

    The recent calculation of the complex isospin-two decay amplitude A_2 with physical kinematics is presented together with exploratory calculations of the isospin-zero decay amplitude A_0. Prospects for accurate calculation of A_0 as well as the mass difference between the K_L and K_S mesons are discussed.

  6. Exotic mesons in quenched lattice QCD

    CERN Document Server

    Bernard, C W; DeTar, C E; Gottlieb, S; Heller, U M; Hetrick, J E; McNeile, C; Rummukainen, K; Sugar, B; Toussaint, D; Wingate, M; Bernard, Claude; Grand, Thomas A. De; Tar, Carleton De; Gottlieb, Steven; Heller, Urs M.; Hetrick, James E.; Neile, Craig Mc; Rummukainen, Kari; Sugar, Bob; Toussaint, Doug; Wingate, Matthew

    1997-01-01

    Since gluons in QCD are interacting fundamental constituents just as quarks are, we expect that in addition to mesons made from a quark and an antiquark, there should also be glueballs and hybrids (bound states of quarks, antiquarks and gluons). In general, these states would mix strongly with the conventional q-bar-q mesons. However, they can also have exotic quantum numbers inaccessible to q-bar-q mesons. Confirmation of such states would give information on the role of "dynamical" color in low energy QCD. In the quenched approximation we present a lattice calculation of the masses of mesons with exotic quantum numbers. These hybrid mesons can mix with four quark (q-bar-q-bar-q-q) states. The quenched approximation partially suppresses this mixing. Nonetheless, our hybrid interpolating fields also couple to four quark states. Using a four quark source operator, we demonstrate this mixing for the 1-+ meson. Using the conventional Wilson quark action, we calculate both at reasonably light quark masses, intend...

  7. Omega meson production in proton-proton collisions

    International Nuclear Information System (INIS)

    The TOF spectrometer is an external experiment fed by the proton accelerator COSY, which is located at the Forschungszentrum Juelich, Germany. While this detector does not utilize a magnetic field for particle identification, it, however, stands out for its high acceptance (approx. 2π in the laboratory frame) and versatility. TOF measures the velocity-vectors of all charged particles, which then are used to completely reconstruct the event pattern. Due to the modular design of the TOF detector, its components can be assembled to ideally match different experimental requirements. This makes it a multipurpose device, which has shown results for many hadronic channels, starting from the pion threshold up to excess energies as high as 1GeV. One of the experimental programs is dedicated to the ω meson production. In proton-proton interactions, this channel has remained largely unstudied until the late 1990s. Then, first experimental data in the direct vicinity of the threshold and at an excess energy of ε=320 MeV became available. We have published data on ω production for two (intermediate) excess energies of ε=93 MeV and ε=173 MeV. In parallel, a considerable interest on the part of theory arose, since the reaction dynamics of ω-meson production in nucleon-nucleon collisions has an impact on many fields of modern physics. For example, there is an ongoing discussion whether 'missing resonances' may (help to) explain the phenomena observed in dense matter. These resonances would couple to the pω, but not to the pπ channel. Although predicted by many authors, until now no pω resonance was found experimentally; the strangeness content of the nucleon is still an open question. One possible key to an answer is the ratio of the total cross sections of ω to φ - mesons, which experimentally is about a factor of seven larger than simple SU predictions (often referred to as 'violation of the OZI-rule'). However, this comparison is only valid assuming similar

  8. Extracting the $\\eta^\\prime$ meson mass from gluonic correlators in lattice QCD

    CERN Document Server

    Fukaya, H; Hashimoto, S; Kaneko, T

    2015-01-01

    Calculation of the eta-prime meson mass is a notoriously difficult problem, as it requires evaluation of the disconnected diagram which is costly and noisy. In this work, we use a gluonic operator to extract the eta-prime state after smearing the link variables through the Wilson flow. With this choice, one can avoid a large cancellation of pion contribution between the connected and disconnected diagrams. We obtain the eta-prime meson mass on lattices with three different lattice spacings and two physical volumes, which allow us to estimate its continuum and large volume limits.

  9. Two-photon Anderson localization in a disordered quadratic waveguide array

    International Nuclear Information System (INIS)

    We theoretically investigate two-photon Anderson localization in a χ (2) waveguide array with off-diagonal disorder. The nonlinear parametric down-conversion process would enhance both the single-photon and the two-photon Anderson localization. In the strong disorder regime, the two-photon position correlation exhibits a bunching distribution around the pumped waveguides, which is independent of pumping conditions and geometrical structures of waveguide arrays. Quadratic nonlinearity can be supplied as a new ingredient for Anderson localization. Also, our results pave the way for engineering quantum states through nonlinear quantum walks. (paper)

  10. Quantum criticality at the Anderson transition: A typical medium theory perspective

    Science.gov (United States)

    Mahmoudian, Samiyeh; Tang, Shao; Dobrosavljević, Vladimir

    2015-10-01

    We present a complete analytical and numerical solution of the typical medium theory (TMT) for the Anderson metal-insulator transition. This approach self-consistently calculates the typical amplitude of the electronic wave functions, thus representing the conceptually simplest order-parameter theory for the Anderson transition. We identify all possible universality classes for the critical behavior, which can be found within such a mean-field approach. This provides insights into how interaction-induced renormalizations of the disorder potential may produce qualitative modifications of the critical behavior. We also formulate a simplified description of the leading critical behavior, thus obtaining an effective Landau theory for Anderson localization.

  11. Routes Towards Anderson-Like Localization of Bose-Einstein Condensates in Disordered Optical Lattices

    Science.gov (United States)

    Schulte, T.; Drenkelforth, S.; Kruse, J.; Ertmer, W.; Arlt, J.; Sacha, K.; Zakrzewski, J.; Lewenstein, M.

    2005-10-01

    We investigate, both experimentally and theoretically, possible routes towards Anderson-like localization of Bose-Einstein condensates in disordered potentials. The dependence of this quantum interference effect on the nonlinear interactions and the shape of the disorder potential is investigated. Experiments with an optical lattice and a superimposed disordered potential reveal the lack of Anderson localization. A theoretical analysis shows that this absence is due to the large length scale of the disorder potential as well as its screening by the nonlinear interactions. Further analysis shows that incommensurable superlattices should allow for the observation of the crossover from the nonlinear screening regime to the Anderson localized case within realistic experimental parameters.

  12. Routes Towards Anderson-Like Localization of Bose-Einstein Condensates in Disordered Optical Lattices

    International Nuclear Information System (INIS)

    We investigate, both experimentally and theoretically, possible routes towards Anderson-like localization of Bose-Einstein condensates in disordered potentials. The dependence of this quantum interference effect on the nonlinear interactions and the shape of the disorder potential is investigated. Experiments with an optical lattice and a superimposed disordered potential reveal the lack of Anderson localization. A theoretical analysis shows that this absence is due to the large length scale of the disorder potential as well as its screening by the nonlinear interactions. Further analysis shows that incommensurable superlattices should allow for the observation of the crossover from the nonlinear screening regime to the Anderson localized case within realistic experimental parameters

  13. Spectroscopy of mesonic molecules with heavy-light flavour mesons

    CERN Document Server

    Rathaud, D P

    2016-01-01

    In this work, we have calculated the mass spectra and decay properties of dimesonic (meson-antimeson) bound state in the variational scheme. The intermesonic interaction considered as the Hellmann potential and One Pion Exchange potential. The mass spectra of the $D\\bar{D^{*}}$, $D\\bar{D_{s}^{*}}$, $D_{s}\\bar{D^{*}}$, $D_{s}\\bar{D_{s}^{*}}$, $D^{*}\\bar{D^{*}}$, $D_{s}^{*}\\bar{D_{s}^{*}}$, $D\\bar{B^{*}}$, $D\\bar{B_{s}^{*}}$, $D_{s}\\bar{B^{*}}$, $D_{s}\\bar{B_{s}^{*}}$, $B^{*}\\bar{D}$,$B^{*}\\bar{D_{s}}$, $B\\bar{B^{*}}$, $B_{s}\\bar{B^{*}}$, $B_{c}\\bar{B^{*}}$, $B^{*}\\bar{B^{*}}$, $B^{*}\\bar{B_{s}^{*}}$, $B_{s}^{*}\\bar{B_{s}^{*}}$ etc.. are calculated. The states X(3872), $X_{2c}(4013)$ ,$Z_{b}(10610)/X_{b}$ and $Z_{b}(10650)/X_{b2}$ are compared with $D\\bar{D^{*}}$, $D^{*}\\bar{D^{*}}$, $B\\bar{B^{*}}$ and $B^{*}\\bar{B^{*}}$ dimesonic bound states. To probe the molecular structure of the compared states, we have calculated the decay properties sensitive to their long and short distance structure of hadorinc molecul...

  14. Excited meson radiative transitions from lattice QCD using variationally optimized operators

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Experimental Status of Exotic Mesons and the GlueX Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Daniel Carman

    2006-10-22

    One of the unanswered and most fundamental questions in physics regards the nature of the confinement mechanism of quarks and gluons in QCD. Exotic hybrid mesons manifest gluonic degrees of freedom and their spectroscopy will provide the data necessary to test assumptions in lattice QCD and the specific phenomenology leading to confinement. Within the past two decades a number of experiments have put forth tantalizing evidence for the existence of exotic hybrid mesons in the mass range below 2 GeV. This talk represents an overview of the available data and what has been learned. In looking toward the future, the GlueX experiment at Jefferson Laboratory represents a new initiative that will perform detailed spectroscopy of the light-quark meson spectrum. This experiment and its capabilities will be reviewed.

  16. Lattice calculation of 1-+ hybrid mesons with improved Kogut-Susskind fermions

    International Nuclear Information System (INIS)

    We report on a lattice determination of the mass of the exotic 1-+ hybrid meson using an improved Kogut-Susskind action. Results from both quenched and dynamical quark simulations are presented. We also compare with earlier results using Wilson quarks at heavier quark masses. The results on lattices with three flavors of dynamical quarks show effects of sea quarks on the hybrid propagators which probably result from coupling to two meson states. We extrapolate the quenched results to the physical light quark mass to allow comparison with experimental candidates for the 1-+ hybrid meson. The lattice result remains somewhat heavier than the experimental result, although it may be consistent with the π1(1600)

  17. Lattice calculation of $1^{-+}$ hybrid mesons with improved Kogut-Susskind fermions

    CERN Document Server

    Bernard, C; DeTar, C E; Gottlieb, S; Gregory, E B; Heller, U M; Osborn, J; Sugar, R; Toussaint, D; Gottlieb, Steven

    2003-01-01

    We report on a lattice determination of the mass of the exotic $1^{-+}$ hybrid meson using an improved Kogut-Susskind action. Results from both quenched and dynamical quark simulations are presented. We also compare with earlier results using Wilson quarks at heavier quark masses. The results on lattices with three flavors of dynamical quarks show effects of sea quarks on the hybrid propagators which probably result from coupling to two meson states. We extrapolate the quenched results to the physical light quark mass to allow comparison with experimental candidates for the $1^{-+}$ hybrid meson. The lattice result remains somewhat heavier than the experimental result, although it may be consistent with the $\\pi_1(1600)$.

  18. Existence of the critical endpoint in the vector meson extended linear sigma model

    CERN Document Server

    Kovács, Peter; Wolf, György

    2016-01-01

    The chiral phase transition of the strongly interacting matter is investigated at nonzero temperature and baryon chemical potential mu_B within an extended (2+1) flavor Polyakov constituent quark-meson model which incorporates the effect of the vector and axial vector mesons. The effect of the fermionic vacuum and thermal fluctuations computed from the grand potential of the model is taken into account in the curvature masses of the scalar and pseudoscalar mesons. The parameters of the model are determined by comparing masses and tree-level decay widths with experimental values in a chi^2-minimization procedure which selects between various possible assignments of scalar nonet states to physical particles. We examine the restoration of the chiral symmetry by monitoring the temperature evolution of condensates and the chiral partners' masses and of the mixing angles for the pseudoscalar eta-eta' and the corresponding scalar complex. We calculate the pressure and various thermodynamical observables derived from...

  19. About neutral mesons and particle oscillations in the light of field-theoretical prescriptions of Weinberg

    CERN Document Server

    Slad, L M

    2016-01-01

    The postulated universality of the Weinberg's prescriptions on the diagonalization of the mass term of the Lagrangian without increasing the total number of entities leads to the following conclusions: the set of neutral $K$-mesons consists of two elements, $K_{S}^{0}$ and $K_{L}^{0}$; the states $K^{0}$ and $\\bar{K}^{0}$ do not exist as physical objects (in the form of particles or "particle mixtures"); the absence of the states $K^{0}$ and $\\bar{K}^{0}$ destroys grounds for introducing the notion of their oscillations. The conclusions concerning the neutral $K$-mesons are also applicable to the neutral $D$-, $B$- and $B_{s}$-mesons.A theoretical and experimental vulnerability of the neutrino oscillation concept is noted.

  20. Elements of beauty physics

    International Nuclear Information System (INIS)

    The aim of this manuscript is to present a few theoretical aspects of the B-meson physics. In the first chapter we discuss the hypothesis of quark-hadron duality on which most studies are based. The second chapter is dedicated to the discussion of another hypothesis used in the studies of non-leptonic processes: the factorization assumption. This simplifying hypothesis enables the study of non-leptonic B-mesons decays into 2 other mesons. The last 2 chapters are dedicated to the problem that arises in the production of orbital momentum l=1 when B-mesons decay (B → D**): experimental data go the wrong way with experimental data given by any phenomenological theoretical model. We propose an attempt to solve this inconsistency through a QCD calculation on lattices. A complete feasibility study through a QCD computation on lattices will require a computer with parallel architecture optimized for QCD. (A.C.)

  1. Photoproduction and Decay of Light Mesons in CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Amaryan, Moskov Jamalovich [Old Dominion University

    2013-08-01

    We present preliminary experimental results on photoproduction and decay of light mesons measured with CLAS setup at JLAB . This include Dalitz decay of pseudoscalar and vector mesons, radiative decay of pseudoscalar mesons as well hadronic decays of pseudoscalar and vector mesons. The collected high statistics in some of decay channels exceeds the world data by an order of magnitude and some other decay modes are observed for the first time. It is shown how the CLAS data will improve the world data on transition form factors of light mesons, Dalitz plot analyses, branching ratios of rare decay modes and other fundamental properties potentially accessible through the light meson decays.

  2. Hadron Physics at COSY

    CERN Document Server

    Gillman, A R; Kleber, V; Krewald, S; Morsch, H P; Rathmann, F; Sibirtsev, A A

    2003-01-01

    The workshop 'Hadron Physics at COSY' held from July 7th to July 10th 2003 in Bad Honnef brought together experimentalists and theoreticians from various fields of hadron physics to identify the key physics questions, which can be addressed with (un-) polarized proton and deuteron induced reactions at COSY. Topics discussed include charge symmetry breaking, elastic and inelastic nucleon-nucleon and nucleon-deuteron interactions, hadrons in the medium, mesonic bound states, meson and baryon resonances, and the hyperon-nucleon system. In addition prospects of the planned GSI facility were discussed. These Miniproceedings contain besides short summaries of the presentations the most relevant references for the field.

  3. Price--Anderson Act: the insurance industry's view

    International Nuclear Information System (INIS)

    The insurance industry feels the expense of providing insurance coverage under the Price-Anderson Act is justified because it encouraged development of nuclear power and assured protection for the public in the event of an accident. Insurance pools have been instituted in about 20 countries in order to distribute the risk on a worldwide basis. Changes in the original Act allow an off-site claimant to get compensation with defense waived and provide for the transition of financial responsibility from the public to the private sector. To date the pools have refunded $9.7 of $12.7 million (73 percent) of the premiums to the insured and the remainder has grown into a $45 million fund, which reflects the success of the nuclear industry and the regulatory agencies in establishing a safe record. This record covers 60 power reactors, 50 research and development reactors, waste disposal sites, and about 50 nuclear facilities. With the exception of reactor operators and fuel reprocessors, the insurance is voluntary at premiums ranging from $1000 to $260,000. A total of $600,000 has been paid in claims

  4. Magnetic flux creep in HTSC and Anderson-Kim theory

    International Nuclear Information System (INIS)

    The theoretical and experimental data on flux creep in high-temperature superconductors (HTSC) were analyzed in the review paper. On the one hand, the main attention is paid to the most striking experimental results which have had a significant influence on the investigations of flux creep in HTSC. On the other hand, the analysis of theoretical studies is concentrated on the works, which explain the features of flux creep on the basis of the Anderson-Kim (AK) theory modifications, and received previously unsufficient attention. However, it turned out that the modified AK theory could explain a lot of features of flux creep in HTSC: the scaling behaviour of current-voltage curves of HTSC, the finite rate of flux creep at ultra low temperatures, the logarithmic dependence of effective pinning potential as a function of transport current and its decrease with temperature. The harmonic potential field which is used in this approach makes it possible to solve accurately the both problems: viscous vortex motion and flux creep in this field. Moreover the distribution of pinning potential and the interaction of vortices with each other are taken into account in the approach. Thus, the modification of the AK theory consists, essentially, in its detailed elaboration and approaching to real situations in superconductors

  5. Anderson metal-insulator transitions with classical magnetic impurities

    Science.gov (United States)

    Jung, Daniel; Kettemann, Stefan; Slevin, Keith

    2016-04-01

    We study numerically the effects of classical magnetic impurities on the Anderson metal-insulator transition. We find that a small concentration of Heisenberg impurities enhances the critical disorder amplitude Wc with increasing exchange coupling strength J . The resulting scaling with J is analyzed which supports an anomalous scaling prediction by Wegner due to the combined breaking of time-reversal and spin-rotational symmetry. Moreover, we find that the presence of magnetic impurities lowers the critical correlation length exponent ν and enhances the multifractality parameter α0. The new value of ν improves the agreement with the value measured in experiments on the metal-insulator transition (MIT) in doped semiconductors like phosphor-doped silicon, where a finite density of magnetic moments is known to exist in the vicinity of the MIT. The results are obtained by a finite-size scaling analysis of the geometric mean of the local density of states which is calculated by means of the kernel polynomial method. We establish this combination of numerical techniques as a method to obtain critical properties of disordered systems quantitatively.

  6. What should the Price--Anderson Act accomplish

    International Nuclear Information System (INIS)

    A historical review of the Price-Anderson Act's goals is followed by recommendations for amendments to improve guarantees of public safety. Failures of the original Act are identified as its failure to cover some accident situations appropriately and to provide incentives for promoting public safety. Legislation should correct these problems and be extended to all energy areas. Legislation based on worst-case situations is not found to be meaningful in terms of increasing safety or estimating comprehensive compensation because it relies on invalidated assumptions, which are still useful in safety awareness. Legislation could take the direction of putting 1.5 percent of the reactor cost into a fund, with the vendor and licensee contributing equal parts. When an incident occurs at any reactor, another one percent is put in by every reactor plus a $1 million penalty proportioned among those responsible. The Federal government would cover amounts above the fund, which would have no limit. Compensation to public funds by the industry would be a social decision based on the social and economic impact

  7. Oscillazioni del mesone D^0

    CERN Document Server

    Schiraldi, Vito; Morello, Michael Joseph

    In fisica delle particelle, con il termine di "oscillazione" si indica la trasformazione di una particella neutra nella sua antiparticella e viceversa, fenomeno dovuto al fatto che gli autostati di flavor non sono autostati della matrice di massa. Il Modello Standard delle interazioni fondamentali predice che l'oscillazione del mesone D^0 avvenga su tempi molto maggiori di una vita media, e appaia perciò come un effetto piccolo, inferiore al percento, in contrasto con il caso dei mesoni B^0 e B^0_s che oscillano con molta maggiore rapidità. Sperimentalmente, l'oscillazione dei mesoni D^0 è rimasta inosservata fino a tempi recenti: la prima evidenza sperimentale dell'esistenza di un effetto di oscillazione è stata ottenuta soltanto nella primavera del 2007 dagli esperimenti BaBar (SLAC, USA) e Belle (KEKB, Japan). Nell'agosto 2007 anche l’esperimento CDF (Fermilab, USA) ha presentato una evidenza simile, basata sull'analisi di una parte del campione di dati disponibile. La tesi descrive gli aspetti speri...

  8. Quarkonium Contribution to Meson Molecules

    CERN Document Server

    Cincioglu, E; Ozpineci, A; Yilmazer, A U

    2016-01-01

    Starting from a molecular picture for the X(3872) resonance, this state and its J^{PC}=2++ HQSS partner [X2(4012)] are analyzed within a model which incorporates possible mixings with 2P charmonium states. Since it is reasonable to expect the bare chi_{c1}(2P) to be located above the D\\bar D* threshold, but relatively close to it, the presence of the charmonium state provides an effective attraction that will contribute to bind the X(3872), but it will not appear in the 2++ sector. Indeed in this latter sector, the chi_{c2}(2P) should provide an effective small repulsion, because it is placed well below the D*\\bar D* threshold. We show how the 1++ and 2++ bare charmonium poles are modified due to the D(*)\\bar D(*) loop effects, and the first one is moved to the complex plane. The meson loops produce, besides some shifts in the masses of the charmonia, a finite width for the 1++ dressed charmonium state. On the other hand, the X(3872) and X2(4012) start developing some charmonium content, which is estimated by...

  9. Radiative B Meson Decay as a Probe of Physics Beyond the Standard Model: Time-Dependent CP Violation in B0 --> KS pi0 gamma and the B --> phi K gamma Branching Fraction

    Energy Technology Data Exchange (ETDEWEB)

    Tuggle, Joseph Marion, IV; /Maryland U.

    2009-01-22

    The author presents measurements of radiative B meson decays to the final states K{sub s}{sup 0}{pi}{sup 0}{gamma} and K{phi}{gamma} based on data collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. In a data sample of 467 million B{bar B} pairs, the time-dependent CP asymmetry in B{sup 0} {yields} K{sub s}{sup 0}{pi}{sup 0}{gamma} decays is measured in two regions of K{sub s}{sup 0}-{pi}{sup 0} invariant mass. In the K* region, 0.8 < m(K{sub s}{sup 0}{pi}{sup 0}) < 1.0 GeV/c{sup 2}, we find S{sub K*{gamma}} = -0.03 {+-} 0.29 {+-} 0.03 and C{sub K*{gamma}} = -0.14 {+-} 0.16 {+-} 0.03; in the range 1.1 < m(K{sub s}{sup 0}{pi}{sup 0}) < 1.8 GeV/c{sup 2}, they find S{sub K{sub s}{sup 0}{pi}{sup 0}{gamma}} = -0.78 {+-} 0.59 {+-} 0.09 and C{sub K{sub s}{sup 0}{pi}{sup 0}{gamma}} = -0.36 {+-} 0.33 {+-} 0.04. With a sample of 228 million B{bar B} pairs they measure the branching fraction {Beta}(B{sup +} {yields} K{sup +}{phi}{gamma}) = (3.5 {+-} 0.6 {+-} 0.4) x 10{sup -6} and set the limit {Beta}(B{sup 0} {yields} K{sup 0}{phi}{gamma}) < 2.7 x 10{sup -6} at 90% confidence level. The direct CP asymmetry in B{sup +} {yields} K{sup +}{phi}{gamma} is found to be A{sub CP} = (-26 {+-} 14 {+-} 5)%. In each case the uncertainties are statistical and systematic, respectively.

  10. The Anderson transition due to random spin-orbit coupling in two-dimension

    OpenAIRE

    Asada, Yoichi; Slevin, Keith; Ohtsuki, Tomi

    2003-01-01

    We report an analysis of the Anderson transition in an SU(2) model with chiral symmetry. Clear single parameter scaling behaviour is observed. We estimate the critical exponent for the divergence of the localization length to be $\

  11. Non-Fermi liquid fixed points of a two-channel Anderson model

    International Nuclear Information System (INIS)

    A generalized two-channel Anderson Hamiltonian is diagonalized via the numerical renormalization group. The spectrum shows non-Fermi liquid fixed point for isotropic channel hybridization and normal Fermi liquid for the anisotropic case

  12. Wyodak-Anderson clinker in the Powder River Basin, Wyoming and Montana (prbclkg.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This ArcView shapefile contains a polygon representation of the Wyodak-Anderson clinker in the Powder River Basin, Wyoming and Montana. This theme was created...

  13. Non-Fermi liquid fixed points of a two-channel Anderson model

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, J.V.B.; Oliveira, L.N. de; Cox, D.L.; Libero, V.L. E-mail: valter@if.sc.usp.br

    2001-05-01

    A generalized two-channel Anderson Hamiltonian is diagonalized via the numerical renormalization group. The spectrum shows non-Fermi liquid fixed point for isotropic channel hybridization and normal Fermi liquid for the anisotropic case.

  14. Charmed and strange pseudoscalar meson decay constants from HISQ simulations

    CERN Document Server

    Bazavov, A; Bouchard, C; DeTar, C; Du, D; El-Khadra, A X; Foley, J; Freeland, E D; Gamiz, E; Gottlieb, Steven; Heller, U M; Kim, J; Komijani, J; Kronfeld, A S; Laiho, J; Levkova, L; Mackenzie, P B; Neil, E T; Simone, J N; Sugar, R L; Toussaint, D; Van de Water, R S; Zhou, R

    2013-01-01

    We update our determinations of $f_{D^+}$, $f_{D_s}$, $f_K$, and quark mass ratios from simulations with four flavors of HISQ dynamical quarks. The availability of ensembles with light quarks near their physical mass means that we can extract physical results with only small corrections for valence- and sea-quark mass mistunings instead of a chiral extrapolation. The adjusted valence-quark masses and lattice spacings may be determined from an ensemble-by-ensemble analysis, and the results for the quark mass ratios then extrapolated to the continuum limit. Our central values of the charmed meson decay constants, however, come from an alternative analysis, which uses staggered chiral perturbation theory for the heavy-light mesons, and allows us to incorporate data at unphysical quark masses where statistical errors are often smaller. A jackknife analysis propagated through all of these steps takes account of the correlations among all the quantities used in the analysis. Systematic errors from the finite spatia...

  15. Thomas Anderson Goudge and the introduction of symbolic logic at the University of Toronto

    OpenAIRE

    Anellis, Irving H.

    1997-01-01

    Thomas Anderson Goudge was the first member of the philosophy department faculty to teach a course in modern mathematical logic at the University of Toronto. We provide here a brief discussion of the origin of Goudge's interest in logic and of how he came to introduce symbolic logic courses into the philosophy department curriculum at the University of Toronto. Much of the information presented here is based upon John G. Slater's three-page essay "Thomas Anderson Goudge" pre...

  16. Nonequilibrium transport in the Anderson-Holstein model with interfacial screening

    Science.gov (United States)

    Perfetto, Enrico; Stefanucci, Gianluca

    Image charge effects in nanoscale junctions with strong electron-phonon coupling open the way to unexplored physical scenarios. Here we present a comprehensive study of the transport properties of the Anderson-Holstein model in the presence of dot-lead repulsion. We propose an accurate many-body approach to deal with the simultaneous occurrence of the Franck-Condon blockade and the screening-induced enhancement of the polaron mobility. Remarkably, we find that a novel mechanism of negative differential conductance origins from the competition between the charge blocking due to the electron-phonon interaction and the charge deblocking due to the image charges. An experimental setup to observe this phenomenon is discussed. References [1]E. Perfetto, G. Stefanucci and M. Cini, Phys. Rev. B 85, 165437 (2012). [2] E. Perfetto and G. Stefanucci, Phys. Rev. B 88, 245437 (2013). [3] E. Perfetto and G. Stefanucci, Journal of Computational Electronics 14, 352 (2015). E.P. and G.S. acknowledge funding by MIUR FIRB Grant No. RBFR12SW0J.

  17. Bottom-strange mesons in hyperonic matter

    CERN Document Server

    Pathak, Divakar

    2014-01-01

    The in-medium behavior of bottom-strange pseudoscalar mesons in hot, isospin asymmetric and dense hadronic environment is studied using a chiral effective model. The same was recently generalized to the heavy quark sector and employed to study the behavior of open-charm and open-bottom mesons. The heavy quark (anti-quark) is treated as frozen and all medium modifications of these bottom-strange mesons are due to their strange anti-quark (quark) content. We observe a pronounced dependence of their medium mass on baryonic density and strangeness content of the medium. Certain aspects of these in-medium interactions are similar to those observed for the strange-charmed mesons in a preceding investigation, such as the lifting of mass-degeneracy of $B_S^0$ and ${\\bar B}_S^0$ mesons in hyperonic matter, while the same is respected in vacuum as well as in nuclear matter. In general, however, there is a remarkable distinction between the two species, even though the formalism predicts a completely analogous in-medium...

  18. Rare meson decays into very light neutralinos

    CERN Document Server

    Dreiner, H K; Koschade, Daniel; Krämer, M; Langenfeld, Ulrich; O'Leary, Ben

    2009-01-01

    We investigate the bounds on the mass of the lightest neutralino from rare meson decays within the MSSM with and without minimal flavor violation. We present explicit formulae for the two-body decays of mesons into light neutralinos and perform the first complete calculation of the loop-induced decays of kaons to pions and light neutralinos and B mesons to kaons and light neutralinos. We find that the supersymmetric branching ratios are strongly suppressed within the MSSM with minimal flavor violation, and that no bounds on the neutralino mass can be inferred from experimental data, i.e. a massless neutralino is allowed. The branching ratios for kaon and B meson decays into light neutralinos may, however, be enhanced when one allows for non-minimal flavor violation. We find new constraints on the MSSM parameter space for such scenarios and discuss prospects for future kaon and B meson experiments. Finally, we comment on the search for light neutralinos in monojet signatures at the Tevatron and at the LHC.

  19. Rare meson decays into very light neutralinos

    Energy Technology Data Exchange (ETDEWEB)

    Dreiner, H.K.; Grab, S. [Bonn Univ. (Germany). Bethe Center for Theoretical Physics und Physikalisches Inst.; Koschade, D. [RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Physik; London Univ. (United Kingdom). Centre for Reserach in String Theory; Kraemer, M.; O' Leary, B. [RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Physik; Langenfeld, U. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2009-05-15

    We investigate the bounds on the mass of the lightest neutralino from rare meson decays within the MSSM with and without minimal flavor violation. We present explicit formulae for the two-body decays of mesons into light neutralinos and perform the first complete calculation of the loop-induced decays of kaons to pions and light neutralinos and B mesons to kaons and light neutralinos. We find that the supersymmetric branching ratios are strongly suppressed within the MSSM with minimal flavor violation, and that no bounds on the neutralino mass can be inferred from experimental data, i.e. a massless neutralino is allowed. The branching ratios for kaon and B meson decays into light neutralinos may, however, be enhanced when one allows for non-minimal flavor violation. We find new constraints on the MSSM parameter space for such scenarios and discuss prospects for future kaon and B meson experiments. Finally, we comment on the search for light neutralinos in monojet signatures at the Tevatron and at the LHC. (orig.)

  20. Light Vector Mesons in the Nuclear Medium

    CERN Document Server

    Wood, M H; Weygand, D P; Djalali, C; Tur, C; Mosel, U; Mühlich, P; Adams, G; Amaryan, M J; Ambrozewicz, P; Anghinolfi, M; Asryan, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Barrow, S; Battaglieri, M; Bedlinskiy, I; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, B L; Biselli, A S; Blaszczyk, L; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Burkert, V D; Butuceanu, C; Calarco, J R; Careccia, S L; Carman, D S; Carnahan, B; Casey, L; Chen, S; Cheng, L; Cole, P L; Collins, P; Coltharp, P; Crabb, D; Crannell, H; Credé, V; Cummings, J P; Dashyan, N; De Vita, R; De Sanctis, E; Degtyarenko, P V; Denizli, H; Dennis, L; Deur, A; Dharmawardane, K V; Dickson, R; Dodge, G E; Doughty, D; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Feldman, G; Feuerbach, R J; Fradi, A; Funsten, H; Garçon, M; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gordon, C I O; Gothe, R W; Griffioen, K A; Guidal, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hafidi, K; Hakobyan, H; Hakobyan, R S; Hanretty, C; Hardie, J; Hassall, N; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hyde-Wright, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Johnstone, J R; Joo, K; Jüngst, H G; Kalantarians, N; Kellie, J D; Khandaker, M; Khetarpal, P; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Kossov, M; Krahn, Z; Kramer, L H; Kubarovski, V; Kühn, J; Kuhn, S E; Kuleshov, S V; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Ji, Li; Livingston, K; Lu, H Y; MacCormick, M; Markov, N; Mattione, P; McAleer, S; McKinnon, B; McNabb, J W C; Mecking, B A; Mehrabyan, S; Melone, J J; Mestayer, M D; Meyer, C A; Mibe, T; Mikhailov, K; Minehart, R; Mirazita, M; Miskimen, R; Mokeev, V; Moriya, K; Morrow, S A; Moteabbed, M; Müller, J; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Paterson, C; Anefalos Pereira, S; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rosner, G; Rossi, P; Sabati, F; Salamanca, J; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Sharabyan, Yu G; Sharov, D; Shvedunov, N V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Stavinsky, A; Stepanyan, S; Stepanyan, S S; Stokes, B E; Stoler, P; Strakovsky, I I; Strauch, S; Taiuti, M; Tedeschi, D J; Tkabladze, A; Tkachenko, S; Todor, L; Ungaro, M; Vineyard, M F; Vlassov, A V; Watts, D P; Weinstein, L B; Williams, M; Wolin, E; Yegneswaran, A; Zana, L; Zhang, B; Zhang, J; Zhao, B; Zhao, Z W

    2008-01-01

    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 effects such as collisional...

  1. Rare meson decays into very light neutralinos

    International Nuclear Information System (INIS)

    We investigate the bounds on the mass of the lightest neutralino from rare meson decays within the MSSM with and without minimal flavor violation. We present explicit formulae for the two-body decays of mesons into light neutralinos and perform the first complete calculation of the loop-induced decays of kaons to pions and light neutralinos and B mesons to kaons and light neutralinos. We find that the supersymmetric branching ratios are strongly suppressed within the MSSM with minimal flavor violation, and that no bounds on the neutralino mass can be inferred from experimental data, i.e. a massless neutralino is allowed. The branching ratios for kaon and B meson decays into light neutralinos may, however, be enhanced when one allows for non-minimal flavor violation. We find new constraints on the MSSM parameter space for such scenarios and discuss prospects for future kaon and B meson experiments. Finally, we comment on the search for light neutralinos in monojet signatures at the Tevatron and at the LHC. (orig.)

  2. PHYSICS

    CERN Multimedia

    P. Sphicas

    There have been three physics meetings since the last CMS week: “physics days” on March 27-29, the Physics/ Trigger week on April 23-27 and the most recent physics days on May 22-24. The main purpose of the March physics days was to finalize the list of “2007 analyses”, i.e. the few topics that the physics groups will concentrate on for the rest of this calendar year. The idea is to carry out a full physics exercise, with CMSSW, for select physics channels which test key features of the physics objects, or represent potential “day 1” physics topics that need to be addressed in advance. The list of these analyses was indeed completed and presented in the plenary meetings. As always, a significant amount of time was also spent in reviewing the status of the physics objects (reconstruction) as well as their usage in the High-Level Trigger (HLT). The major event of the past three months was the first “Physics/Trigger week” in Apri...

  3. Recollection of meson multiparticle production studies

    International Nuclear Information System (INIS)

    More than fifty years have passed since the author started to study high energy physics theory in Tomonaga's group as a graduate student. At first the status of the meson multiparticle production theory before that time is summarized briefly mentioning the points of theories by (1) Lowis, Oppenheimer and Weuthusen (LOW), (2) Fukuda and Takeda, (3) Heisenberg, (4) Fermi and (5) Landau. Social background in Japan after the World War II is also realistically described. Landau's theory was very interesting as Koba suggested 'What Landau says will be necessarily proven to be true finally.' Then knowledge at that time from the cosmic ray is summarized i.e., the sharp angular distribution of the secondary particles, multiplicity, inelasticity and so on comparing them with the models of Fermi, Heisenberg, LOW and Landau. The nucleon to nuclei collision was studied based on Landau hydrodynamic model assuming the nuclei interact with the nucleus with the tube which the nucleon bores while penetrating a nucleus. Shock waves were solved to obtain energy and entropy distributions. The hydrodynamic model is then considered with the field theoretical view in mind. The limit of Landau model is discussed referring to the irreversible process by Kubo. The relation between elastic scattering and multiparticle production is discussed. Finally the quark cascade model including quark recombination is discussed. This model was invented to avoid the problem at the front part of the fluid which is not in local thermal equilibrium though needed to apply the hydrodynamic model. A new type of model was formulated for this part by using time dependent diffusion equation. (S. Funahashi)

  4. Static-light meson masses from twisted mass lattice QCD

    International Nuclear Information System (INIS)

    We compute the static-light meson spectrum using two-flavor Wilson twisted mass lattice QCD. We have considered five different values for the light quark mass corresponding to 300 MeVPSS mesons. (orig.)

  5. Review of meson spectroscopy: quark states and glueballs

    International Nuclear Information System (INIS)

    A group of three lectures on hadron spectroscopy are presented. Topics covered include: light L = 0 mesons, light L = 1 mesons, antiquark antiquark quark quark exotics, a catalogue of higher quark antiquark excitations, heavy quarkonium, and glueballs

  6. Auxiliary Field Meson Model at Finite Temperature and Density

    CERN Document Server

    Kouno, H; Kashiwa, K; Hamada, M; Tokudome, H; Matsuzaki, M; Yahiro, M

    2005-01-01

    Starting from many quark interactions, we construct a nonlinear sigma-omega model at finite temperature and density. The mesons are introduced as auxiliary fields. Effective quark-meson couplings are strongly related to effective meson masses, since they are derived simultaneously from the original many quark interactions. In this model, even if the effective omega-meson mass decreases due to the partial chiral restoration, the equation of state (EOS) of nuclear matter can become soft.

  7. Parabolic Anderson Model in a Dynamic Random Environment: Random Conductances

    Science.gov (United States)

    Erhard, D.; den Hollander, F.; Maillard, G.

    2016-06-01

    The parabolic Anderson model is defined as the partial differential equation ∂ u( x, t)/ ∂ t = κ Δ u( x, t) + ξ( x, t) u( x, t), x ∈ ℤ d , t ≥ 0, where κ ∈ [0, ∞) is the diffusion constant, Δ is the discrete Laplacian, and ξ is a dynamic random environment that drives the equation. The initial condition u( x, 0) = u 0( x), x ∈ ℤ d , is typically taken to be non-negative and bounded. The solution of the parabolic Anderson equation describes the evolution of a field of particles performing independent simple random walks with binary branching: particles jump at rate 2 d κ, split into two at rate ξ ∨ 0, and die at rate (- ξ) ∨ 0. In earlier work we looked at the Lyapunov exponents λ p(κ ) = limlimits _{tto ∞} 1/t log {E} ([u(0,t)]p)^{1/p}, quad p in {N} , qquad λ 0(κ ) = limlimits _{tto ∞} 1/2 log u(0,t). For the former we derived quantitative results on the κ-dependence for four choices of ξ : space-time white noise, independent simple random walks, the exclusion process and the voter model. For the latter we obtained qualitative results under certain space-time mixing conditions on ξ. In the present paper we investigate what happens when κΔ is replaced by Δ𝓚, where 𝓚 = {𝓚( x, y) : x, y ∈ ℤ d , x ˜ y} is a collection of random conductances between neighbouring sites replacing the constant conductances κ in the homogeneous model. We show that the associated annealed Lyapunov exponents λ p (𝓚), p ∈ ℕ, are given by the formula λ p({K} ) = {sup} {λ p(κ ) : κ in {Supp} ({K} )}, where, for a fixed realisation of 𝓚, Supp(𝓚) is the set of values taken by the 𝓚-field. We also show that for the associated quenched Lyapunov exponent λ 0(𝓚) this formula only provides a lower bound, and we conjecture that an upper bound holds when Supp(𝓚) is replaced by its convex hull. Our proof is valid for three classes of reversible ξ, and for all 𝓚

  8. Attractive Hubbard model with disorder and the generalized Anderson theorem

    International Nuclear Information System (INIS)

    Using the generalized DMFT+Σ approach, we study the influence of disorder on single-particle properties of the normal phase and the superconducting transition temperature in the attractive Hubbard model. A wide range of attractive potentials U is studied, from the weak coupling region, where both the instability of the normal phase and superconductivity are well described by the BCS model, to the strong-coupling region, where the superconducting transition is due to Bose-Einstein condensation (BEC) of compact Cooper pairs, formed at temperatures much higher than the superconducting transition temperature. We study two typical models of the conduction band with semi-elliptic and flat densities of states, respectively appropriate for three-dimensional and two-dimensional systems. For the semi-elliptic density of states, the disorder influence on all single-particle properties (e.g., density of states) is universal for an arbitrary strength of electronic correlations and disorder and is due to only the general disorder widening of the conduction band. In the case of a flat density of states, universality is absent in the general case, but still the disorder influence is mainly due to band widening, and the universal behavior is restored for large enough disorder. Using the combination of DMFT+Σ and Nozieres-Schmitt-Rink approximations, we study the disorder influence on the superconducting transition temperature Tc for a range of characteristic values of U and disorder, including the BCS-BEC crossover region and the limit of strong-coupling. Disorder can either suppress Tc (in the weak-coupling region) or significantly increase Tc (in the strong-coupling region). However, in all cases, the generalized Anderson theorem is valid and all changes of the superconducting critical temperature are essentially due to only the general disorder widening of the conduction band

  9. Exclusive vector meson production at HERMES

    Directory of Open Access Journals (Sweden)

    Movsisyan Aram

    2014-06-01

    Full Text Available Exclusive electroproduction of vector mesons has been measured on hydrogen and deuterium targets at HERMES using the 27.6 GeV electron/positron beam of HERA. From this process, more information can be obtained about generalized parton distributions (GPDs, which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs and transverse-position information (form factors. The study of the azimuthal distribution of the decay products via spin-density matrix elements provide constraints on helicity-amplitudes used to describe exclusive vector-meson production. Recent results from the HERMES experiment on the production of rho, omega and phi mesons will be presented.

  10. Exclusive vector meson production at HERMES

    Science.gov (United States)

    Movsisyan, Aram

    2014-06-01

    Exclusive electroproduction of vector mesons has been measured on hydrogen and deuterium targets at HERMES using the 27.6 GeV electron/positron beam of HERA. From this process, more information can be obtained about generalized parton distributions (GPDs), which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs) and transverse-position information (form factors). The study of the azimuthal distribution of the decay products via spin-density matrix elements provide constraints on helicity-amplitudes used to describe exclusive vector-meson production. Recent results from the HERMES experiment on the production of rho, omega and phi mesons will be presented.

  11. Massive mesons in Weyl-Dirac theory

    Science.gov (United States)

    Mirabotalebi, S.; Ahmadi, F.; Salehi, H.

    2008-01-01

    In order to study the mass generation of the vector fields in the framework of a conformal invariant gravitational model, the Weyl-Dirac theory is considered. The mass of the Weyl’s meson fields plays a principal role in this theory, it connects basically the conformal and gauge symmetries. We estimate this mass by using the large-scale characteristics of the observed universe. To do this we firstly specify a preferred conformal frame as a cosmological frame, then in this frame, we introduce an exact possible solution of the theory. We also study the dynamical effect of the massive vector meson fields on the trajectories of an elementary particle. We show that a local change of the cosmological frame leads to a Hamilton-Jacobi equation describing a particle with an adjustable mass. The dynamical effect of the massive vector meson field presents itself in the form of a correction term for the mass of the particle.

  12. Magnetic properties of ground-state mesons

    CERN Document Server

    Simonis, Vytautas

    2016-01-01

    Starting with the bag model a method for the study of the magnetic properties (magnetic moments, magnetic dipole transition widths) of ground-state mesons is developed. We calculate the M1 transition moments and use them subsequently to estimate the corresponding decay widths. These are compared with experimental data, where available, and with the results obtained in other approaches. Finally, we give the predictions for the static magnetic moments of all ground-state vector mesons including those containing heavy quarks. We have a good agreement with experimental data for the M1 decay rates of light as well as heavy mesons. Therefore, we expect our predictions for the static magnetic properties (usual magnetic moments) to be of sufficiently high quality, too.

  13. Nuclear fission induced by Pi mesons

    International Nuclear Information System (INIS)

    Pi mesons are an important part of the interactions among strongly-interacting particles, and their reactions with complex nuclei involve reactions with a wide range of interactions and time scales, with the slowest being the familiar fission process. Decades of effort have produced a wide range of fission data with stopped and energetic charged beams, both positive and negative. These results are the result of many uncoordinated studies, but in total can give a very good view of pion-induced fission. This review will compare and combine the measurements, with comparisons to a range of theoretical expectations. It is found that the nature of fission induced by pi mesons is not significantly different from fission induced by other energetic particles, in spite of the special features of the mesonic beam. This specific arena of nuclear science may now be considered complete. (author)

  14. Mesons beyond the naive quark model

    CERN Document Server

    Amsler, C

    2004-01-01

    We discuss theoretical predictions for the existence of exotic (non-quark-model) mesons and review prominent experimental candidates. These are especially the f0(1500) and f0(1710) mesons for the scalar glueball, fJ(2220) for the tensor glueball, η(1410) for the pseudoscalar glueball, f0(600), f0(980), a0(980), the still to be firmly established κ(800) and the f2(1565) for or two-meson states, and π1(1400), π1(1600) for hybrid states. We conclude that some of these states exist, offer our views and discuss crucial issues that need to be investigated both theoretically and experimentally.

  15. Weak decays of K and π mesons

    International Nuclear Information System (INIS)

    Through a special interplay of strong and weak interactions, small but significant pieces with a ''wrong'' flavor could be introduced into wave functions of mesons. Thus, e.g., not only a (u bar s) pair, but also a (u bar d) pair can be found with some probability within K+, etc. The possible importance of such ''anomalous'' terms in understanding of K-meson decays is discussed in a new scheme. The scheme is characterized by diagrammatic calculations of full amplitudes in the long-distance environment. Two classes of models which correctly reproduce the main K-meson branching ratios and the ΔI=1/2 rule are constructed. The predictive power of the scheme is then tested in a decay of a kaon into a pion and a light hyperphoton

  16. Two, three, many body systems involving mesons

    CERN Document Server

    Oset, E; Khemchandani, K P; Roca, L; Yamagata, J

    2011-01-01

    In this talk we show recent developments on few body systems involving mesons. We report on an approach to Faddeev equations using chiral unitary dynamics, where an explicit cancellation of the two body off shell amplitude with three body forces stemming from the same chiral Lagrangians takes place. This removal of the unphysical off shell part of the amplitudes is most welcome and renders the approach unambiguous, showing that only on shell two body amplitudes need to be used. Within this approach, systems of two mesons and one baryon are studied, reproducing properties of the low lying $1/2^+$ states. On the other hand we also report on multirho and $K^*$ multirho states which can be associated to known meson resonances of high spin.

  17. eta' meson production in proton-proton collisions

    OpenAIRE

    K Nakayama; Arellano, H. F.; Durso, J.W.; Speth, J.(Institut für Kernphysik, Forschungszentrum Jülich, Jülich, D-52425, Germany)

    1999-01-01

    The pp -> pp eta' reaction is investigated within a relativistic meson-exchange model of hadronic interactions. We explore the role of nucleonic and mesonic, as well as the N* resonance currents, in producing eta' mesons. In order to learn more about the production mechanisms, new measurements in the energy region far from the threshold are required.

  18. B meson spectrum and decay constant from Nf=2 simulations

    International Nuclear Information System (INIS)

    We report on the status of an ALPHA Collaboration project to extract quantities for B physics phenomenology from Nf=2 lattice simulations. The framework is Heavy Quark Effective Theory (HQET) expanded up to the first order of the inverse b-quark mass. The couplings of the effective theory are determined by imposing matching conditions of observables computed in HQET with their counterpart computed in QCD. That program, based on Nf=2 simulations in a small physical volume with Schroedinger functional boundary conditions, is now almost finished. On the other side the analysis of configurations selected from the CLS ensembles, in order to measure HQET hadronic matrix elements, has just started recently so that only results obtained at a single lattice spacing, a=0:07 fm, is discussed. We give our first results for the b-quark mass and for the B meson decay constant. (orig.)

  19. On the ultimate precision of meson mixing observables

    CERN Document Server

    Jubb, Thomas; Lenz, Alexander; Tetlalmatzi-Xolocotzi, Gilberto

    2016-01-01

    Meson mixing is considered to be an ideal candidate for new physics searches. Current experimental precision has greatly increased over the recent years, excelling in several cases the theoretical precision. A possible limit in the theoretical accuracy could be a hypothetcial breakdown of quark-hadron duality. We propose a simple model for duality violations and give stringent bounds on such effects for mixing observables, indicating regions, where future measurements of $\\Delta \\Gamma_d$, $a_{sl}^d$ and $a_{sl}^s$ would be clear signals of new physics. Finally, we turn our attention to the charm sector, and reveal that already a modest duality violation of about $20 \\%$ could explain the huge difference between HQE predictions for D-mixing and experimental data.

  20. Effect of coulomb interaction on Anderson localization; Effet de l'interaction coulombienne sur la localisation d'Anderson dans des systemes de basses dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Waintal, X

    1999-09-10

    We study the quantum mechanics of interacting particles in a disordered system, and in particular, what happens to Anderson localisation when interaction is taken into account. In the first part,one looks at the excited states of two particles in one dimension. For this model, it has been shown (Shepelyansky 1994) that a local repulsive interaction can partially destroy Anderson localisation. Here, we show that this model has similarities with the three-dimensional Anderson model at the metal-insulator transition. In particular, the maximum of rigidity obtained in the spectral statistics correspond to some intermediary statistics that cannot be described by random matrix theory neither by a Poisson statistics. The wave functions show a multifractal behaviour and the spreading of the center of mass of a wave packet is logarithmic in time. The second part deals with the ground state of a finite density of spinless fermions in two dimensions. After the scaling theory of localisation, it was commonly accepted that there was no metal in two dimensions. This idea has been challenged by the observation of a metal-insulator transition in low density electron gas (Kravchenko et al. 1994). We propose a scenario in which a metallic phase occurs between the Anderson insulator and the pinned Wigner crystal. This intermediate phase is characterized by an alignment of the local currents flowing in the system. (author)

  1. Study of the charmed mesons production at LEP with the ALEPH Detector; Etude de la production des mesons charmes au LEP avec le detecteur ALEPH

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, C.

    1995-06-16

    This work describes two aspects of Charm Physics as one can undertake to do at LEP. The first aspect concerns the Charm production in the Z{sup 0} boson decay through the measurement of the c quark forward-backward asymmetry. The second is about the spectroscopy of charmed mesons via an excited states D{sup **} research. (author). 63 refs., 78 figs., 16 tabs.

  2. Research in experimental nuclear physics. Progress report, 1 April 1984-31 March 1985

    International Nuclear Information System (INIS)

    This report summarizes the work carried out by personnel from the University of Texas at Austin at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF) during the calendar year 1984. The research activities involved experiments done with the Energetic Pion Channel and Spectrometer (EPICS), the High Resolution Spectrometer (HRS), and some work has been done at Argonne National Laboratory and Kernforschungsanlage, Juelich, West Germany. A brief overview of work supported by this contract, a list of abstracts of papers reported at scientific meetings, and a list of published papers and preprints are given. These papers summarize experiments undertaken this year and in the proceeding year and indicate the work accomplished by the participants in this program of medium energy nuclear physics research. Studies include parameters of the neutron density distributions for the Ca isotopes for the analysis of π+- elastic scattering, the excitation of ΔS = 1 transitions via pion inelastic scattering in light nuclei, 12C(π+,π+') inelastic scattering at very small angles, pion-induced double charge exchange reaction, and evidence for the population of a low-spin Δ-hole state at 248 MeV was found in 12C via 13C(p,d)12C* at 800 MeV

  3. The coupling of heavy mesons to the pion on the lattice; Couplage des mesons lourds au pion sur reseau

    Energy Technology Data Exchange (ETDEWEB)

    Herdoiza, G

    2004-04-15

    The QCD non-perturbative effects are among the main sources of uncertainty in our present knowledge of the Standard Model phenomenology. I will present some of the methods which can be used to study these effects, and I will particularly treat the case of lattice QCD. Effective theories can be combined to the lattice approach in order to study the chiral and the heavy quark sectors. I will give some examples of how these properties can be successfully applied to the quark flavour phenomenology. The coupling of heavy mesons to the pion is related to a non-perturbative quantity, noted g-bar, which is required to extract physical results from the effective theory combining both chiral and heavy quark symmetry. This coupling is also involved in the study of the form factors appearing in the heavy to light semi-leptonic decays. These heavy meson decays are used to extract some of the CKM matrix elements which are know, up to now, only with large uncertainties. Moreover, the chiral effects of heavy mesons depend on pion loops whose vertices are precisely the coupling g-bar. These are some of the reasons why the theoretical and experimental determination of this coupling is required. I will present the results of its studies on the lattice and I will compare them to those obtained through several other methods. I will therefore describe these different approaches, their limitations and possible improvements, both from the point of view of the method and of its application to the determination of the coupling g-bar. (author)

  4. Scalar mesons from an effective Lagrangian approach

    CERN Document Server

    Fariborz, Amir H; Schechter, Joseph

    2007-01-01

    A brief discussion of the recent interest in light scalar mesons motivates the study of a generalized linear sigma model. In an SU(3) flavor invariant version of the model there is a prediction that the the lighter scalars have sizeable "four quark" content. It is further predicted that one of the singlet scalars should be exceptionally light. Due to the presence of scalar mesons, the model gives "controlled" corrections to the current algebra formula for threshold pion pion scattering. These corections act in the direction to improve agreement with current experiments.

  5. Heavy Meson Molecules in Effective Field Theory

    OpenAIRE

    AlFiky, Mohammad T.; Gabbiani, Fabrizio; Petrov, Alexey A.

    2006-01-01

    We consider the implications from the possibility that the recently observed state X(3872) is a meson-antimeson molecule. We write an effective Lagrangian consistent with the heavy-quark and chiral symmetries needed to describe X(3872). We explore the consequences of the assumption that X(3872) is a molecular bound state of D^{*0} and anti-D^0 mesons for the existence of bound states in the D^0-anti-D^0 and D^{*0}-anti-D^{*0}.

  6. Turbulent meson condensation in quark deconfinement

    Directory of Open Access Journals (Sweden)

    Koji Hashimoto

    2015-06-01

    Full Text Available In a QCD-like strongly coupled gauge theory at large Nc, using the AdS/CFT correspondence, we find that heavy quark deconfinement is accompanied by a coherent condensation of higher meson resonances. This is revealed in non-equilibrium deconfinement transitions triggered by static, as well as quenched electric fields even below the Schwinger limit. There, we observe a “turbulent” energy flow to higher meson modes, which finally results in the quark deconfinement. Our observation is consistent with seeing deconfinement as a condensation of long QCD strings.

  7. Mass shift of -meson in nuclear matter

    Indian Academy of Sciences (India)

    J R Morones-Ibarra; Mónica Menchaca Maciel; Ayax Santos-Guevara; Felipe Robledo Padilla

    2013-03-01

    The propagation of -meson in nuclear matter is studied in the Walecka model, by assuming that the sigma couples to a pair of nucleon–antinucleon states and to particle–hole states. The in-medium effect of - mixing is also studied. For completeness, the coupling of sigma to two virtual pions was also considered. It is found that the -meson mass decreases with respect to its value in vacuum and that the contribution of the - mixing effect on the mass shift is relatively small.

  8. Diffractive hadroproduction of charmed D mesons

    International Nuclear Information System (INIS)

    We have observed charmed D meson production from a hydrogen target in a 217 GeV/c π- beam. Hadronic decays in the K+-π+-π+- channels were reconstructed in the Chicago Cyclotron Spectrometer at Fermilab. The proton recoil angle and momentum transfer were programmed so that objects of mass near that of two D mesons would be produced in the forward direction. A mass peak in the 40-MeV bin at 1875 MeV was found in each channel. The cross section for D+- production is 6--10 μb

  9. Isospin-violating mixing in meson nonets

    International Nuclear Information System (INIS)

    Segregation into ideally mixed nonets results when the OZI-violating interaction which would mix u anti u, d anti d, and s anti s mesons into isospin and SU(3) eigenstates is much weaker than the s anti s-d anti d mass difference. We show that the d anti d-u anti u mass difference can begin to induce a similar segregation into d anti d and anti u mesons which leads to large isospin violations. An experimental example of such large isospin breaking (approx. 30%) which we predict has probably already been seen in f → K anti K. (orig.)

  10. CP violation in B meson decays

    Science.gov (United States)

    Noguchi, S.; Belle Group

    2003-06-01

    CP violation in neutral B meson decays has been observed confirming the prediction of the Kobayashi-Maskawa model where introduction of six quaks naturally induces CP violation in the weak interaction. The measurements of CP asymmetryc in B meson decays were made at the newly constructed Asymmetric B factories, which consist of high luminosity, ebergy-asymmetric e+e- colliders (KEKB and PEP-II) and detectors (Belle and BaBar). The results are in good agreement and are consistent with other experimental results within the framework of the Standard Model.

  11. Soft-wall modelling of meson spectra

    CERN Document Server

    Afonin, S S

    2016-01-01

    The holographic methods inspired by the gauge/gravity correspondence from string theory have been actively applied to the hadron spectroscopy in the last eleven years. Within the phenomenological bottom-up approach, the linear Regge-like trajectories for light mesons are naturally reproduced in the so-called "Soft-wall" holographic models. I will give a very short review of the underlying ideas and technical aspects related to the meson spectroscopy. A generalization of soft-wall description of Regge trajectories to arbitrary intercept is proposed. The problem of incorporation of the chiral symmetry breaking is discussed.

  12. $B$ and $B_s$ Meson Spectroscopy

    CERN Document Server

    Godfrey, S; Swanson, E S

    2016-01-01

    Properties of bottom and bottom-strange mesons are computed in two relativized quark models. Model masses and wavefunctions are used to predict radiative transition rates and the $^3P_0$ quark pair creation model is used to compute strong decay widths. A comparison to recently observed bottom and bottom-strange states is made. We find that there are numerous excited $B$ and $B_s$ mesons that have relatively narrow widths and significant branching ratios to simple final states such as $B\\pi$, $B^*\\pi$, $BK$, and $B^*K$ that could be observed in the near future.

  13. Quasi-exotic open-flavor mesons

    CERN Document Server

    Hilger, T

    2016-01-01

    Meson states with exotic quantum numbers arise naturally in a covariant bound-state framework in QCD. We investigate the consequences of shifting quark masses such that the states are no longer restricted to certain C-parities, but only by J^P. Then, a priori, one can no longer distinguish exotic or conventional states. In order to identify signatures of the different states to look for experimentally, we provide the behavior of masses, leptonic decay constants, and orbital-angular-momentum decomposition of such mesons, as well as the constellations in which they could be found. Most prominently, we consider the case of charged quasi-exotic excitations of the pion.

  14. PHYSICS

    CERN Document Server

    D. Acosta

    2010-01-01

    A remarkable amount of progress has been made in Physics since the last CMS Week in June given the exponential growth in the delivered LHC luminosity. The first major milestone was the delivery of a variety of results to the ICHEP international conference held in Paris this July. For this conference, CMS prepared 15 Physics Analysis Summaries on physics objects and 22 Summaries on new and interesting physics measurements that exploited the luminosity recorded by the CMS detector. The challenge was incorporating the largest batch of luminosity that was delivered only days before the conference (300 nb-1 total). The physics covered from this initial running period spanned hadron production measurements, jet production and properties, electroweak vector boson production, and even glimpses of the top quark. Since then, the accumulated integrated luminosity has increased by a factor of more than 100, and all groups have been working tremendously hard on analysing this dataset. The September Physics Week was held ...

  15. PHYSICS

    CERN Multimedia

    J. Incandela

    There have been numerous developments in the physics area since the September CMS week. The biggest single event was the Physics/Trigger week in the end of Octo¬ber, whereas in terms of ongoing activities the “2007 analyses” went into high gear. This was in parallel with participation in CSA07 by the physics groups. On the or¬ganizational side, the new conveners of the physics groups have been selected, and a new database for man¬aging physics analyses has been deployed. Physics/Trigger week The second Physics-Trigger week of 2007 took place during the week of October 22-26. The first half of the week was dedicated to working group meetings. The ple¬nary Joint Physics-Trigger meeting took place on Wednesday afternoon and focused on the activities of the new Trigger Studies Group (TSG) and trigger monitoring. Both the Physics and Trigger organizations are now focused on readiness for early data-taking. Thus, early trigger tables and preparations for calibr...

  16. PHYSICS

    CERN Multimedia

    P. Sphicas

    The CPT project came to an end in December 2006 and its original scope is now shared among three new areas, namely Computing, Offline and Physics. In the physics area the basic change with respect to the previous system (where the PRS groups were charged with detector and physics object reconstruction and physics analysis) was the split of the detector PRS groups (the old ECAL-egamma, HCAL-jetMET, Tracker-btau and Muons) into two groups each: a Detector Performance Group (DPG) and a Physics Object Group. The DPGs are now led by the Commissioning and Run Coordinator deputy (Darin Acosta) and will appear in the correspond¬ing column in CMS bulletins. On the physics side, the physics object groups are charged with the reconstruction of physics objects, the tuning of the simulation (in collaboration with the DPGs) to reproduce the data, the provision of code for the High-Level Trigger, the optimization of the algorithms involved for the different physics analyses (in collaboration with the analysis gr...

  17. New physics with beauty

    Indian Academy of Sciences (India)

    Rahul Sinha

    2000-07-01

    We review the effects of new physics on CP asymmetries and decays of mesons. Possible sources and corresponding signals for new physics are studied briefly. We discuss how the decay mode → sℓℓ$ (and → * ℓℓ) will enable us to understand the nature of new physics. We also examine the possibility of truly clean signature of new physics – a signature based on observables alone and without hadronic uncertainties.

  18. B mesons phenomenology and lattice QCD; Phenomenologie des mesons B et chromodynamique quantique sur reseau

    Energy Technology Data Exchange (ETDEWEB)

    Blossier, B

    2006-06-15

    We have studied some phenomenological aspects of the B meson physics by using lattice QCD, which is a non perturbative method (based on the first principles of Quantum Field Theory) of computing Green functions of the theory. Pionic couplings g{sub 1} and g{sub 2}, parameterizing the effective chiral Lagrangian which describes interactions between heavy-light mesons and soft pions, have been computed beyond the quenched approximation (at N{sub f} = 2). We have renormalized the operator q-bar{gamma}{sub {mu}}{gamma}{sup 5}q non perturbatively by using chiral Ward identities. We obtain g{sub 1} = 0.4/0.6 and g{sub 2} = -0.1/-0.3. We have estimated from an un-quenched simulation (at N{sub f} = 2) the strange quark mass: the non perturbative renormalisation scheme RI-MOM has been applied. After the matching in the MS scheme the result is m{sub s}(2 GeV) = 101 {+-} 8(-0,+25) MeV. We have proposed a method to calculate on the lattice the Heavy Quark Effective Theory form factors of the semileptonic transitions B {yields} D{sup **} at zero recoil. The renormalisation constant of the operator h-bar{gamma}{sub i}{gamma}{sup 5}D{sub j}h has been computed at one-loop order of the perturbation theory. We obtain {tau}{sub 1/2}(1) = 0.3/0.5 and {tau}{sub 3/2}(1) 0.5/0.7. Eventually the bag parameter B{sub B{sub s}} associated the B{sub s} - B{sub s}-bar mixing amplitude in the Standard Model has been estimated in the quenched approximation by using for the strange quark an action which verifies the chiral symmetry at finite lattice spacing a. Thus systematic errors are significantly reduced in the renormalisation procedure because the spurious mixing of the four-fermion operator h-bar{gamma}{sub {mu}}{sub L}qh-bar{gamma}{sub {mu}}{sub L}q with four-fermion operators of different chirality is absent. The result is B{sub B{sub s}} = 0.92(3). (author)

  19. Effect of coupled channels of the multi-channel pion-pion scattering in two-pion transitions of the Upsilon mesons

    Czech Academy of Sciences Publication Activity Database

    Surovtsev, Yu .S.; Bydžovský, Petr; Gutsche, T.; Kaminski, R.; Lyubovitskij, V. E.; Nagy, M.

    Vol. 39. Horny Smokovec : World Scientific Publishing Co Pte Ltd, 2015, s. 1560090. E-ISSN 2010-1945. [The 9th Joint International Hadron Structure 2015 Conference. Horný Smokovec (SK), 29.06.2015-03.07.2015] R&D Projects: GA ČR(CZ) GA15-04301S; GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : coupled–channel formalism * meson–meson scattering * heavy meson decays * scalar and pseudoscalar mesons Subject RIV: BE - Theoretical Physics http://www.worldscientific.com/doi/pdf/10.1142/S2010194515600903

  20. Studies of Nucleon Resonance Structure in Exclusive Meson Electroproduction

    CERN Document Server

    Aznauryan, I G; Braun, V; Brodsky, S J; Burkert, V D; Chang, L; Chen, Ch; El-Bennich, B; Cloët, I C; Cole, P L; Edwards, R G; Fedotov, G V; Giannini, M M; Gothe, R W; Lin, Huey-Wen; Kroll, P; Lee, T -S H; Melnitchouk, W; Mokeev, V I; Peña, M T; Ramalho, G; Roberts, C D; Santopinto, E; de Teramond, G F; Tsushima, K; Wilson, D J

    2013-01-01

    Studies of the structure of excited baryons are key to the N* program at Jefferson Lab. Within the first year of data taking with the Hall B CLAS12 detector following the 12 GeV upgrade, a dedicated experiment will aim to extract the N* electrocouplings at high photon virtualities Q2. This experiment will allow exploration of the structure of N* resonances at the highest photon virtualities ever yet achieved, with a kinematic reach up to Q2 = 12 GeV2. This high-Q2 reach will make it possible to probe the excited nucleon structures at distance scales ranging from where effective degrees of freedom, such as constituent quarks, are dominant through the transition to where nearly massless bare-quark degrees of freedom are relevant. In this document, we present a detailed description of the physics that can be addressed through N* structure studies in exclusive meson electroproduction. The discussion includes recent advances in reaction theory for extracting N* electrocouplings from meson electroproduction off pro...