B-meson factories: Physics, machines and detectors

International Nuclear Information System (INIS)

Kolanoski, H.

1990-10-01

This report gives a short survey of the present status of B-meson factory plans and discussions at different laboratories. The physics motivation for an e + e - machine running with the highest possible luminosity in the Γ(4S) energy region is outlined emphasizing the possibility to observe CP violation in the B-meson system. The technical concepts for such machines together with the basic luminosity limitations are discussed. Finally, the requirements on a detector which is able to cover the rich physics program are presented. (orig.)

Oxygen enhancement ratio for negative pi mesons

International Nuclear Information System (INIS)

Hall, E.J.; Astor, M.

1979-01-01

Experiments were performed at the Los Alamos Meson Physics Facility (LAMPF) to determine the oxygen enhancement ratio (OER) for the clinically used beam of negative pi mesons. V79 Chinese hamster cells, cultured in vitro, were used as the biological test system; hypoxia was produced by metabolic depletion as a result of sealing 2 million cells in 1 ml glass ampules. The Bragg peak of the pion depth dose curve was spread out to cover 10 cm by using a dynamic range shifter. Cells were irradiated at the center of the spead out Bragg peak, where the dose/rate was 0.1 Gy/min over a 6 x 6 cm field. The OER obtained was 2.2, compared with 3.8 obtained for γ rays under the same conditions

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.

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)

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

LOS ALAMOS: Winds of change

Energy Technology Data Exchange (ETDEWEB)

Anon.

1984-03-15

The seventeenth annual Users' Group Meeting of the Los Alamos Meson Physics Facility (LAMPF) felt the winds of change. LAMPF Director Louis Rosen noted that recent progress at the 800 MeV proton linac should not hide the fact that these are difficult times. Extra funding for operations together with good luck in sustaining 800-900 μA beam for lengthy operating cycles have resulted in high utilization and effective running for difficult experiments such as neutrino scattering and the 'Crystal Box' measurement of rare muon decays. New impetus has been given to nuclear spectroscopy with the incorporation of a polarized target (partly from KEK) on the proton spectrometer, while the proton storage ring and beam areas will extend the LAMPF programme in 1985.

Pion physics at the meson factories

International Nuclear Information System (INIS)

Nagle, D.E.; Johnson, M.B.; Measday, D.F.

1987-01-01

Pi meson probes have contributed much to our ideas about how neutrons and protons are distributed and move relative to each other in nuclei, and along with other probes, to our understanding of basic symmetries in particle physics

New physics effects from meson decays

Indian Academy of Sciences (India)

Abstract. 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.

Plans for a new pulsed spallation source at Los Alamos

International Nuclear Information System (INIS)

Pynn, R.

1993-01-01

Los Alamos National Laboratory has proposed to change the emphasis of research at its Meson Physics Facility (LAWF) by buabg a new pulsed spallation source for neutron scattering research. The new source would have a beam power of about one megawatt shared between two neutron production targets, one operating at 20 Hz and the other at 40 Hz. It would make use of much of the existing proton linac and would be designed to accommodate a later upgrade to a beam power of 5 MW or so. A study of technical feasibility is underway and will be published later this year

General developments in the Los Alamos Nuclear Physics group (T-16)

International Nuclear Information System (INIS)

Young, P.G.; Chadwick, M.B.

2000-01-01

Nuclear physics activities in support of nuclear data development by the newly formed ''Nuclear Physics'' group (T-16) at Los Alamos are summarized. Activities such as the development of a new Hauser-Feshbach/preequilibrium reaction theory code, improvements to and reissue of the existing GNASH reaction theory code, nuclear cross section evaluation in the context of ENDF/B-VI, development of a new medium-energy optical model potential, new fission neutron spectrum calculations with the Los Alamos model, and development of new 6-group delayed neutron constants for ENDF/B-VI are described. (author)

Mesonic effects in nuclear physics

International Nuclear Information System (INIS)

Johnson, M.

1978-01-01

The relation between mesons and nucleons and the properties of nuclear matter, as presently understood, is considered in these lectures. Feynman diagrams, meson theoretical nucleon-nucleon interactions, mesonic components in nuclear wave functions, direct observation of mesonic components in NN scattering above the pion production threshold, nuclear matter theory, and pion condensation are treated. 120 references

Discovery of omega meson, first neutral vector meson

International Nuclear Information System (INIS)

Anon.

1976-01-01

A personal account of the discovery of the ω meson is given by researcher B. Maglich. His account includes such topics as early and unsuccessful searches for a neutral vector meson (by himself and others), eventual discovery of the rho meson, the Goldhaber effect, and the observation and characterization of the ω meson. Explanatory physics notes on electromagnetic structure experiments and the determination of the quantum numbers of the ω meson are provided for nonspecialists. Also included are an outline of the relation between vector mesons and nuclear forces, a reprint of the Physical Review Letter on Evidence for a T = 0 three-pion resonance, and a scientific autobiography of the researcher. 14 figures, 1 table

A calculation of the physical mass of sigma meson

International Nuclear Information System (INIS)

Morones-Ibarra, J.R.; Santos-Guevara, Ayax

2007-01-01

We calculate the physical mass and the width of the sigma meson by considering that it couples in vacuum to two virtual pions. The mass is calculated by using the spectral function, and we find that it is about 600 MeV. In addition, we obtained 220 MeV as the value for the width of its spectral function. The value obtained for the mass is in good agreement with that reported in the Particle Data Book for the σ meson, which is also named f 0 (600). This result also shows that σ-meson can be considered as a two-pion resonance. (author)

Hypernuclear physics with a neutral meson spectrometer

International Nuclear Information System (INIS)

Peng, J.C.

1993-01-01

The (K - , π degrees) reaction, which complements the (K - , π - ) and the (π + , K + ) reactions, offers another means to study hypernuclear physics. The physics motivation for measuring the (K - , π degrees) reaction is discussed. The feasibility for detecting π degrees using the LAMPF Neutral Meson Spectrometer is studied with Monte-Carlo simulations. We conclude that the (K - , π degrees) reaction can be well measured at existing kaon beam lines

Experience at the Los Alamos Meson Physics Facility with the use of alloy Inconel 718 as an enclosure for a beam degrader and as a proton beam entry window

International Nuclear Information System (INIS)

Sommer, W.F.; Ferguson, P.D.; Brown, R.D.; Cedillo, C.M.; Zimmerman, E.

1994-01-01

Operation of the Los Alamos Meson Physics Facility (LAMPF) began in 1972 and continues at present. An injector delivers protons to a 0.8 kin long linear accelerator which produces a particle energy of 800 MeV; the protons are then transported to a variety of experimental areas. The proton beam is transported in a vacuum tube, controlled and bent by electromagnets. The highest intensity beam, at a maximum level of 1 mA, is delivered to the experimental area designated as Area A. At the end of the experimental area, the beam is transported through an interface between beamline vacuum and one atmosphere air pressure. This interface is made of metal and is generally referred to as a beam entry window. At LAMPF, after the beam has exited the vacuum tube, it becomes incident on a number of experiments or ''targets.'' These include capsules for radiation damage studies, a beam ''degrader'' for the long-term neutrino experiment, and as many nine targets in the Isotope Production (IP) stringer system used to produce medically significant isotopes. Following the IP system is a beam stop used for the purpose its name implies. The beam stop also contains a beam entry window, whose purpose is to separate the 250 psig water cooling environment from I atmosphere of air. The beam entry window, the beam degrader, and the beam stop window are made of alloy Inconel 718, have endured a lengthy irradiation service time at LAMPF, and are the subject of this report

New directions in physics. The Los Alamos 40th anniversary

International Nuclear Information System (INIS)

Metropolis, N.; Kerr, D.M.; Rota, G.C.

1987-01-01

In 1983 the outstanding scientists gathered in Los Alamos to celebrate the 40th anniversary of the laboratory. This volume contains the papers presented in that meeting. It presents many of the important advances made in physics over the intervening forty years and provides an idea of the possibilities for the future. Among the contributors are eight Nobel Laureates. The contents include: Los Alamos in the 1980s; tiny computers obeying quantum mechanical laws; present, and future of nuclear magnetic resonance; experimental evidence that an asteroid impact led to the extinction of many species 65 million years ago; the lunar laboratory; the future of particle accelerators: Post WWII and now; models, hypotheses and approximations; comments on three thermonuclear paths for the synthesis of helium; and the sad augurs mock their own passage; experiments on time reversal symmetry and parity; on the course of our magnetic fusion energy enterprise; early days in the Lawrence Laboratory; nuclear charge distribution in fission; developing larger software systems; reflections on style in physics; tuning up the TPC; remarks on the future of particle physics; supernova theory; how well we meant; history and the hierarchy of structure

B meson physics with polarized electron beams at the SLC

International Nuclear Information System (INIS)

Atwood, W.B.

1988-09-01

The expected large cross-section for e + e - → Z 0 and subsequent decay to b/bar b/ quarks makes the Z 0 an attractive place to pursue B meson physics. In addition, the big Electroweak asymmetries, thought to exist in Z 0 decays to b/bar b/ quarks with polarized electron beams, provide an outstanding handle for observation of such effects as B 0 -/bar B/ 0 mixing. In this paper, the feasibility of such measurements is investigated and, with relatively small samples of Z 0 's (a few hundred thousand), both B/sub d/ and B/sub s/ meson mixing are shown to be measurable. The subject of CP violation in neutral B mesons is discussed last, but presently such measurements seem to be out of reach. 7 refs., 6 figs., 3 tabs

Tensor meson dominance and e+e--physics

International Nuclear Information System (INIS)

Genz, H.; Karlsruhe Univ.; Mallik, S.

1983-01-01

The phenomenological status of tensor meson dominance is reported. Some new results concerning hadronic decays of the 2 ++ -meson chi 2 (3.55) and the heavy lepton tau are also included. Considering experimental errors, tensor meson dominance is in agreement with experiment. (author)

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.

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

International Nuclear Information System (INIS)

Poelakker, K.

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

Perspective of meson science

International Nuclear Information System (INIS)

Yamazaki, T.; Nagamine, K.

1992-01-01

Unstable particles such as mesons and muons are now used in various research domains of physics, chemistry, engineering, and life sciences. This book is aimed at summarizing the present exploratory activities and giving future perspectives from a very broad scope. It contains 27 contributions in a wide range of subjects, such as μSR studies of superconductivities, magnetism, muon beam and μSr methodology, theoretical accounts of muon hyperfine interactions, muon catalyzed fusion processes, metastable exotic atoms, medical diagnostics, strangeness nuclear physics, mesons in nuclei, meson-related nuclear reactions and structure, and exotic decays of mesons

Low-energy meson physics (chiral theory)

International Nuclear Information System (INIS)

Volkov, M.K.; Pervushin, V.N.

1976-01-01

A quantum chiral theory which allows to obtain low-energy expansions of various hadron processes without introducing arbitrary parameters into the theory with the exception of hadron masses and interaction constants is presented. A hypothesis about the dynamic symmetry of strong interactions is suggested. The interaction lagrangian is derived which satisfies conditions of the dynamic symmetry. Examples of the use of the quantum chiral theory for describing low-energy processes of meson interaction are given. It is noted that the results obtained reproduce the actual qualitative pattern of various physical processes and in most cases result in good quantitative agreement with experiments

L3 physics at the Z resonance and a search for the Higgs particle

International Nuclear Information System (INIS)

Coan, T.A.; Kinnison, W.W.; Kapustinsky, J.; Shukla, J.

1997-01-01

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory. Electroweak interactions were studied using the L3 Detector on the Large Electron-Positron Collider (LEP) at the European Center for Nuclear Study (CERN). The specific physics studied utilized the Silicon Microvertex Detector (SMD) of L3, which Los Alamos had previously played a major role in proposing, designing, constructing, and commissioning. This detector enabled L3 to investigate short-lived mesons containing b-quarks

The Los Alamos suite of relativistic atomic physics codes

International Nuclear Information System (INIS)

Fontes, C J; Zhang, H L; Jr, J Abdallah; Clark, R E H; Kilcrease, D P; Colgan, J; Cunningham, R T; Hakel, P; Magee, N H; Sherrill, M E

2015-01-01

The Los Alamos suite of relativistic atomic physics codes is a robust, mature platform that has been used to model highly charged ions in a variety of ways. The suite includes capabilities for calculating data related to fundamental atomic structure, as well as the processes of photoexcitation, electron-impact excitation and ionization, photoionization and autoionization within a consistent framework. These data can be of a basic nature, such as cross sections and collision strengths, which are useful in making predictions that can be compared with experiments to test fundamental theories of highly charged ions, such as quantum electrodynamics. The suite can also be used to generate detailed models of energy levels and rate coefficients, and to apply them in the collisional-radiative modeling of plasmas over a wide range of conditions. Such modeling is useful, for example, in the interpretation of spectra generated by a variety of plasmas. In this work, we provide a brief overview of the capabilities within the Los Alamos relativistic suite along with some examples of its application to the modeling of highly charged ions. (paper)

Intermediate energy nuclear physics (Task C) and charge exchange reactions (Task W). Technical progress report, October 1, 1985-October 1, 1986

International Nuclear Information System (INIS)

Kraushaar, J.J.

1986-10-01

This report describes the experimental work in intermediate energy research carried out over the past year at the University of Colorado. The experimental program is very broad in nature, ranging from investigations in pion-nucleus interactions, nucleon charge exchange, inelastic electron scattering, and nucleon transfer reactions. The experiments were largely carried out at the Los Alamos Meson Physics Facility, but important programs were conducted at the Tri-University Meson Facility at the University of British Columbia, the Indiana University Cyclotron Facility and Netherlands Institute for Nuclear Physics Research (NIKHEF-K)

The current status and possible future of the Los Alamos spallation radiation effects facility

Energy Technology Data Exchange (ETDEWEB)

Borden, M.J.; Sommer, W.F. [Los Alamos National Laboratory, NM (United States)

1995-10-01

The Los Alamos Spallation Radiation Effects Facility (LASREF) has been configured for both proton and spallation neutron irradiations since 1985. The facility makes use of the Los Alamos Meson Physics Facility 1 mA 800 MeV proton beam. Environment controlled proton and neutron irradiations have been demonstrated over the past nine years. The current copper beam stop configuration produces a maximum measured neutron flux of 4.6 x 10{sup 17} m{sup {minus}2}s{sup {minus}1} for energies greater than 1 KeV. The maximum proton flux at the center of Gaussian shaped beam is 1.2 x 10{sup 14} protons cm{sup {minus}2}s{sup {minus}1} with beam spot diameter of 3.5 cm at 2{sigma}. Previously published work has shown that the neutron flux can be increased by a factor of ten by changing the beam stop to tungsten and decreasing the diameter. Expertise exists at Los Alamos to further optimize this design to tailor neutron production and spectrum. Consideration and preliminary planning has also been done for increasing the LAMPF proton current from 1 mA to a few mA with a possible maximum of 10 mA. An upgrade of this type would produce current densities comparable to those proposed for the Accelerator-Driven Transmutation Technologies (ADTT) programs.

Some results of applied spallation physics research at Los Alamos

International Nuclear Information System (INIS)

Russell, G.J.; Gilmore, J.S.

1983-01-01

At the Los Alamos National Laboratory, we have an active effort in the general area of Applied Spallation Physics Research. The main emphasis of this activity has been on obtaining basic data relevant to spallation neutron source development, accelerator breeder technology, and validation of computer codes used in these applications. We present here an overview of our research effort and show some measured and calculated results of differential and clean integral experiments

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

International Nuclear Information System (INIS)

Ali, A.

2007-12-01

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.)

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

Energy Technology Data Exchange (ETDEWEB)

Ali, A.

2007-12-15

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.)

Tensor meson dominance and e/sup +/e/sup -/-physics

Energy Technology Data Exchange (ETDEWEB)

Genz, H [Miami Univ., Coral Gables, FL (USA). Center for Theoretical Studies; Karlsruhe Univ. (T.H.) (Germany, F.R.). Inst. fuer Theoretische Kernphysik); Mallik, S [Karlsruhe Univ. (T.H.) (Germany, F.R.). Inst. fuer Theoretische Kernphysik

1983-01-01

The phenomenological status of tensor meson dominance is reported. Some new results concerning hadronic decays of the 2/sup + +/-meson chi/sub 2/(3.55) and the heavy lepton tau are also included. Considering experimental errors, tensor meson dominance is in agreement with experiment.

Meson spectroscopy experiment at KEK - E/iota puzzle

International Nuclear Information System (INIS)

Tsuru, Tsuneaki

1985-01-01

Physics interests at the KEK (National Laboratory for High Energy Physics) are (1) search for exotic mesons such as glueballs (gg), meiktons (q anti q g) and multiquark states (q sup(2 - )q 2 ), (2) search for missing ordinary mesons (q anti q) and confirmation of unestablished mesons, and (3) new informations of quark contents of mesons, mixing angles of SU(3) singlet-octet and tests of conservations law. Special interest is in search for exotics such as glueballs and meiktons. (2) is a so-called meson spectroscopy experiment. This is important not only in itself but also in identifying newly discovered states as exotics because exotics have often same quantum numbers as ordinary mesons. Contents are the following: glueballs and E/iota puzzles, spectrometer system, experiments, performance of the spectrometer, physics outputs, E/iota puzzles and πI experiment, future plans. (Mori, K.)

Meson 2000 Conference Summary lite

International Nuclear Information System (INIS)

Barnes, T.

2000-01-01

This short contribution is a late MESON2000 conference summary. As appropriate for the 600th anniversary of the Jagiellonian University, it begins with a brief summary of the last 600 years of European history and its place in hadron physics. Next a ''physicist chirality'' order parameter PC is introduced. When applied to MESON2000 plenary speakers this order parameter illustrates the separation of hadron physicists into disjoint communities. The individual plenary talks in MESON2000 are next sorted according to the subconference associated with each of the 36 plenary speakers. Finally, I conclude with a previously unreported Feynman story regarding the use of models in hadron physics. (author)

Spin information from vector-meson decay in photoproduction

International Nuclear Information System (INIS)

Kloet, W.M.; Chiang, W.; Tabakin, F.

1998-01-01

For the photoproduction of vector mesons, all single and double spin observables involving vector-meson two-body decays are defined consistently in the γN center-of-mass frame. These definitions yield a procedure for extracting physically meaningful single and double spin observables that are subject to known rules concerning their angle and energy evolution. As part of this analysis, we show that measuring the two-meson decay of a photo produced ρ or φ does not determine the vector meson's vector polarization, but only its tensor polarization. The vector meson decay into lepton pairs is also insensitive to the vector meson's vector polarization, unless one measures the spin of one of the leptons. Similar results are found for all double spin observables which involve observation of vector-meson decay. To access the vector meson's vector polarization, one therefore needs to either measure the spin of the decay leptons, make an analysis of the background interference effects, or relate the vector meson's vector polarization to other accessible spin observables. copyright 1998 The American Physical Society

Applications of the EPR effect in the particle physics correlated decays of kaon and b-meson pairs with CP violation

International Nuclear Information System (INIS)

Lipkin, H. J.

1989-11-01

The Einstein-Podolsky-Rosen effect arises in particle physics when pairs of neutral K, D or B mesons are created in a definite quantum state, and the decays of the two mesons are correlated. Choosing the decay mode to be detected for one of the two mesons creates a 'polarized beam' on the other side which has interesting and usfull properties. Application to nvestigations of CP violation are discussed. (author)

Meson facility. Powerful new research tool

International Nuclear Information System (INIS)

Lobashev, V.M.; Tavkhelidze, A.N.

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

Nuclear physics accelerator facilities

International Nuclear Information System (INIS)

1988-12-01

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

Experiments on eta-meson production

International Nuclear Information System (INIS)

Peng, J.C.

1985-01-01

Following a review of some highlights of eta-meson characteristics, the status of eta-meson production experiments is reviewed. The physics motivations and first results of two LAMPF experiments on (π,eta) reactions are discussed. Possible future experiments are also discussed. 42 refs., 12 figs., 4 tabs

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

International Nuclear Information System (INIS)

Allred, J.C.; Talley, B.

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

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)

Light meson physics from maximally twisted mass lattice QCD

International Nuclear Information System (INIS)

Baron, R.; Boucaud, P.

2009-12-01

We present a comprehensive investigation of light meson physics using maximally twisted mass fermions for N f =2 mass-degenerate quark flavours. By employing four values of the lattice spacing, spatial lattice extents ranging from 2.0 fm to 2.5 fm and pseudo scalar masses in the range 280 PS < or similar 650 MeV we control the major systematic effects of our calculation. This enables us to confront our data with chiral perturbation theory and extract low energy constants of the effective chiral Lagrangian and derived quantities, such as the light quark mass, with high precision. (orig.)

Physics Division progress report, January 1, 1984-September 30, 1986

International Nuclear Information System (INIS)

Keller, W.E.

1987-10-01

This report provides brief accounts of significant progress in development activities and research results achieved by Physics Division personnel during the period January 1, 1984, through September 31, 1986. These efforts are representative of the three main areas of experimental research and development in which the Physics Division serves Los Alamos National Laboratory's and the Nation's needs in defense and basic sciences: (1) defense physics, including the development of diagnostic methods for weapons tests, weapon-related high-energy-density physics, and programs supporting the Strategic Defense Initiative; (2) laser physics and applications, especially to high-density plasmas; and (3) fundamental research in nuclear and particle physics, condensed-matter physics, and biophysics. Throughout the report, emphasis is placed on the design, construction, and application of a variety of advanced, often unique, instruments and instrument systems that maintain the Division's position at the leading edge of research and development in the specific fields germane to its mission. A sampling of experimental systems of particular interest would include the relativistic electron-beam accelerator and its applications to high-energy-density plasmas; pulsed-power facilities; directed energy weapon devices such as free-electron lasers and neutral-particle-beam accelerators; high-intensity ultraviolet and x-ray beam lines at the National Synchrotron Light Source (at Brookhaven National Laboratory); the Aurora KrF ultraviolet laser system for projected use as an inertial fusion driver; antiproton physics facility at CERN; and several beam developments at the Los Alamos Meson Physics Facility for studying nuclear, condensed-matter, and biological physics, highlighted by progress in establishing the Los Alamos Neutron Scattering Center

Physics with ETA mesons

International Nuclear Information System (INIS)

Liu, Lon-chang.

1989-01-01

Since the advent of pion factories, an impressive amount of information about the nuclear dynamics of the Δ(1232) pion- nucleon resonance has been obtained. The study of this isospin-3/2 resonance has greatly benefited from the fact that π/sup /minus//n and π + p systems are pure I = 3/2 states, which couple only to the Δ in the resonance region. Such isospin selectivity of the pion does not exist, however, for the I = 1/2 N* resonances because it is not possible to form a pure I = 1/2 state with a pion and a nucleon. Eta mesons have zero isospin. Consequently, the /eta/N systems are in a pure I = 1/2 state, and /eta/ can be used to tag those N* resonances to which it strongly couples. We will briefly review the πN interaction from the threshold region to c.m. energy √s ≅1600 MeV. We shall see how improved πN data can help the study of πN interactions. I shall discuss what new information about the hadronic interaction can be learned from the study of eta production in pp collisions. The behavior of eta meson in nuclei will be discussed. The interesting question of the quark structure of /eta/(549) and /eta/'(958) will also be discussed within the framework of a simple model. 19 refs., 13 figs

New physics effects from meson decays

Indian Academy of Sciences (India)

beyond the Standard Model from -meson decays, taking К-parity conserving and violating super- symmetry .... particular choice of the parameter space, can be much higher than the SM ones. .... CLEO has already given some food for thought.

Fifty-one years of Los Alamos Spacecraft

Energy Technology Data Exchange (ETDEWEB)

Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2014-09-04

From 1963 to 2014, the Los Alamos National Laboratory was involved in at least 233 spacecraft. There are probably only one or two institutions in the world that have been involved in so many spacecraft. Los Alamos space exploration started with the Vela satellites for nuclear test detection, but soon expanded to ionospheric research (mostly barium releases), radioisotope thermoelectric generators, solar physics, solar wind, magnetospheres, astrophysics, national security, planetary physics, earth resources, radio propagation in the ionosphere, and cubesats. Here, we present a list of the spacecraft, their purpose, and their launch dates for use during RocketFest

Light meson physics from maximally twisted mass lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Baron, R.; Boucaud, P. [Paris XI Univ., 91 - Orsay (France). Lab. de Physique Theorique; Dimopoulos, P. [Roma Tor Vergata Univ. (Italy). Dipt. di Fisica; INFN, Rome (IT)] (and others)

2009-12-15

We present a comprehensive investigation of light meson physics using maximally twisted mass fermions for N{sub f}=2 mass-degenerate quark flavours. By employing four values of the lattice spacing, spatial lattice extents ranging from 2.0 fm to 2.5 fm and pseudo scalar masses in the range 280

Strange mesonic transition form factor

International Nuclear Information System (INIS)

Goity, J.L.; Musolf, M.J.

1996-01-01

The strange-quark vector current ρ-to-π meson transition form factor is computed at one-loop order using strange meson intermediate states. A comparison is made with a φ-meson dominance model estimate. We find that one-loop contributions are comparable in magnitude to those predicted by φ-meson dominance. It is possible that the one-loop contribution can make the matrix element as large as those of the electromagnetic current mediating vector meson radiative decays. However, due to the quadratic dependence of the one-loop results on the hadronic form factor cutoff mass, a large uncertainty in the estimate of the loops is unavoidable. These results indicate that non-nucleonic strange quarks could contribute appreciable in moderate-parallel Q 2 parallel parity-violating electron-nucleus scattering measurements aimed at probing the strange-quark content of the nucleon. copyright 1996 The American Physical Society

Decommissioning the Los Alamos Molten Plutonium Reactor Experiment (LAMPRE I)

International Nuclear Information System (INIS)

Harper, J.R.; Garde, R.

1981-11-01

The Los Alamos Molten Plutonium Reactor Experiment (LAMPRE I) was decommissioned at the Los Alamos National Laboratory, Los Alamos, New Mexico, in 1980. The LAMPRE I was a sodium-cooled reactor built to develop plutonium fuels for fast breeder applications. It was retired in the mid-1960s. This report describes the decommissioning procedures, the health physics programs, the waste management, and the costs for the operation

B meson physics and related new physics

International Nuclear Information System (INIS)

Tanimoto, Morimitsu

1988-01-01

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 B d 0 -B-bar d 0 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 B d 0 -B-bar d 0 mixing and obtained some interesting results. (author)

B meson physics with polarized electron beams at linear colliders running at the Z0

International Nuclear Information System (INIS)

Atwood, W.B.

1988-12-01

The expected large cross section for e + e - → Z 0 and subsequent decay to b/bar b/ quarks makes the Z 0 an attractive placeto pursue B meson physics. The cross section for b-quark production at the Z 0 is compared to resonance production at the Υ/sub 4s/ and Υ/sub 5s/. In addition the big electroweak asymmetries, thought to exist in Z 0 decays to b/bar b/ quarks with polarized electron beams, provide an outstanding handle for observation of such effects as B 0 - /bar B/ 0 mixing. In this paper, the feasibility of such measurements is investigated and, with relatively small samples of Z 0 's (a few hundred thousand), both B/sub d/ and B/sub s/ meson mixing are shown to be measurable. The subject of CP violation in neutral B mesons is discussed last, but presently such measurements seem to be out of reach. 7 refs., 7 figs., 3 tabs

A high luminosity superconducting mini collider for Phi meson production and particle beam physics

International Nuclear Information System (INIS)

Pellegrini, C.; Robin, D.; Cline, D.; Kolonko, J.; Anderson, C.; Barletta, W.; Chargin, A.; Cornacchia, M.; Dalbacka, G.; Halbach, K.; Lueng, E.; Kimball, F.; Madura, D.; Patterson, L.

1991-01-01

A 510MeV electron-positron collider has been proposed at UCLA to study particle beam physics and Phi-Meson physics, at luminosities larger than 10 32 cm -2 s -1 . The collider consists of a single compact superconducting storage ring (SMC), with bending field of 4 T and a current larger than 1 A. The authors discuss the main characteristics of this system and its major technical components: superconducting dipoles, RF, vacuum, injection

Hot cell chemistry for isotope production at Los Alamos Meson Physics Facility

International Nuclear Information System (INIS)

Barnes, J.W.; Bentley, G.E.; Ott, M.A.; DeBusk, T.P.

1978-01-01

A family of standardized glass and plastic ware has been developed for the unit processes of dissolution, volume reduction, ion exchange, extraction, gasification, filtration, centrifugation, and liquid transfer in the hot cells. Computerized data handling and gamma pulse analysis have been applied to quality control and process development in hot cell procedures for production of isotopes for research in physics and medicine. The above has greatly reduced the time needed to set up for and produce a new isotope

Physics Division progress report, January 1, 1984-September 30, 1986

Energy Technology Data Exchange (ETDEWEB)

Keller, W.E. (comp.)

1987-10-01

This report provides brief accounts of significant progress in development activities and research results achieved by Physics Division personnel during the period January 1, 1984, through September 31, 1986. These efforts are representative of the three main areas of experimental research and development in which the Physics Division serves Los Alamos National Laboratory's and the Nation's needs in defense and basic sciences: (1) defense physics, including the development of diagnostic methods for weapons tests, weapon-related high-energy-density physics, and programs supporting the Strategic Defense Initiative; (2) laser physics and applications, especially to high-density plasmas; and (3) fundamental research in nuclear and particle physics, condensed-matter physics, and biophysics. Throughout the report, emphasis is placed on the design, construction, and application of a variety of advanced, often unique, instruments and instrument systems that maintain the Division's position at the leading edge of research and development in the specific fields germane to its mission. A sampling of experimental systems of particular interest would include the relativistic electron-beam accelerator and its applications to high-energy-density plasmas; pulsed-power facilities; directed energy weapon devices such as free-electron lasers and neutral-particle-beam accelerators; high-intensity ultraviolet and x-ray beam lines at the National Synchrotron Light Source (at Brookhaven National Laboratory); the Aurora KrF ultraviolet laser system for projected use as an inertial fusion driver; antiproton physics facility at CERN; and several beam developments at the Los Alamos Meson Physics Facility for studying nuclear, condensed-matter, and biological physics, highlighted by progress in establishing the Los Alamos Neutron Scattering Center.

LOS ALAMOS: Candidate events in a search for neutrino oscillations

International Nuclear Information System (INIS)

Anon.

1995-01-01

In the past several years, a number of experiments have searched for neutrino oscillations,where a neutrino of one type (say muon-antineutrinos) spontaneously transforms into a neutrino of another type (say electron antineutrinos). For this phenomenon to occur, neutrinos must be massive and the apparent conservation law of lepton families must be violated. At this time, there is no broadly accepted evidence for neutrino oscillations from a terrestrial experiment. The Liquid Scintillator Neutrino Detector (LSND) experiment (July 1993, page 10) at the Los Alamos Meson Physics facility (LAMPF) is designed to search with high sensitivity for muon-antineutrino electronantineutrino oscillations from positive muon decay at rest. The collaboration consists of groups from the University of California at Riverside, San Diego and Santa Barbara, the University California Intercampus Institute for Research at Particle Accelerators, Embry Riddle Aeronautical University, Linfield College, Los Alamos National Laboratory, Louisiana State University, Louisiana Tech University, the University of New Mexico, Southern University, and Temple University. LAMPF is an intense source of low energy neutrinos due to its 1 mA proton intensity and 800 MeV energy. The neutrino source is well understood because almost all neutrinos arise from positive pion or muon decay; negative muons and pions are readily captured in the iron of the shielding and copper of the beam stop. The production of kaons and heavier mesons is negligible at these energies. The electron-antineutrino rate is calculated to be only 4 x 10 -4 that of muon-antineutrinos in the neutrino energy range between 36 and 52.8 MeV, so that the observation of a significant electronantineutrino rate would be evidence for muon-antineutrino electronantineutrino oscillations. The LSND detector consists of an approximately cylindrical tank 8.3 m long by 5.7 m in diameter. The centre of the detector is 30 m from the neutrino source. On the

The η' meson from lattice QCD

International Nuclear Information System (INIS)

Jansen, K.; Michael, C.; Urbach, C.

2008-04-01

We study the flavour singlet pseudoscalar mesons from first principles using lattice QCD. With N f =2 flavours of light quark, this is the so-called η 2 meson and we discuss the phenomenological status of this. Using maximally twisted-mass lattice QCD, we extract the mass of the η 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.)

Photoproduction opportunities at CEBAF: Meson spectroscopy and the physics of flying φ's

International Nuclear Information System (INIS)

Dzierba, A.R.

1994-01-01

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 φ'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 φ's. The physics contemplated at e + e - φ factories, such as CP and CPT tests, might be also studied at CEBAF with completely different and complementary systematics; e.g. having the φ's decay in flight may offer distinct advantages over φ's produced at rest

Application of heavy-light methods to B meson physics

International Nuclear Information System (INIS)

Eichten, E.; Hockney, G.; Thacker, H.B.

1989-01-01

The heavy-light method is applied to the study of the B meson spectrum, the pseudoscalar decay constant f B , the mixing (B) parameter, and exclusive semileptonic B meson decays. Preliminary results are discussed for f B and the B parameter at β = 5.7 and κ = 0.165 on a 12 3 x 24 lattice and at β = 5.9 and κ = 0.158 on a 16 3 x 32 lattice. 9 refs., 2 figs., 2 tabs

Studies in medium energy physics

International Nuclear Information System (INIS)

Green, A.; Hoffmann, G.W.; McDonough, J.; Purcell, M.J.; Ray, R.L.; Read, D.E.; Worn, S.D.

1991-12-01

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

A physicists guide to The Los Alamos Primer

International Nuclear Information System (INIS)

Reed, B Cameron

2016-01-01

In April 1943, a group of scientists at the newly established Los Alamos Laboratory were given a series of lectures by Robert Serber on what was then known of the physics and engineering issues involved in developing fission bombs. Serber’s lectures were recorded in a 24 page report titled The Los Alamos Primer , which was subsequently declassified and published in book form. This paper describes the background to the Primer and analyzes the physics contained in its 22 sections. The motivation for this paper is to provide a firm foundation of the background and contents of the Primer for physicists interested in the Manhattan Project and nuclear weapons. (invited comment)

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.

Scalar mesons and radiative vector meson decays

International Nuclear Information System (INIS)

Gokalp, A.; Ylmaz, O

2002-01-01

The light scalar mesons with vacuum quantum numbers J p =0 ++ have fundamental importance in understanding low energy QCD phenomenology and the symmetry breaking mechanisms in QCD. The nature and quark substructure of the best known scalar mesons, isoscalar σ(500), f0(980) and isovector a0(980) have been a subject of continuous controversy. The radioactive decay of neutral vector mesons ρ, w and φ into a single photon and a pair of neutral pseudoscalar mesons have been studied in order to obtain information on the nature of these scalar mesons. For such studies, it is essential that a reliable understanding of the mechanisms for these decays should be at hand. In this work, we investigate the particularly interesting mechanism of the exchange of scalar mesons for the radiative vector meson decays by analysing the experimental results such as measured decay rates and invariant mass spectra and compare them with the theoretical prediction of different reaction mechanisms

The WNR facility - a pulsed spallation neutron source at the Los Alamos Scientific Laboratory

International Nuclear Information System (INIS)

Russell, G.J.; Lisowski, P.W.; King, N.S.P.

1978-01-01

The Weapons Neutron Research facility (WNR) at the Los Alamos Scientific Laboratory is the first operating example of a new class of pulsed neutron sources using the X(p,n)Y spallation reaction. At present, up to 10 microamperes of 800-MeV protons from the Clinton P. Anderson Meson Physics Facility (LAMPF) linear accelerator bombard a Ta target to produce an intense white-neutron spectrum from about 800 MeV to 100 keV. The Ta target can be coupled with CH 2 and H 2 O moderators to produce neutrons of lower energy. The time structure of the WNR proton beam may be varied to optimize neutron time-of-flight (TOF) measurements covering the energy range from several hundred MeV to a few meV. The neutronics of the WNR target and target/moderator configurations have been calculated from 800 MeV to 0.5 eV. About 11 neutrons per proton are predicted for the existing Ta target. Some initial neutron TOF data are presented and compared with calculations

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

International Nuclear Information System (INIS)

Allred, J.C.

1982-03-01

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

LOS ALAMOS: Hadron future

International Nuclear Information System (INIS)

Ernst, David J.

1992-01-01

At a Workshop on the Future of Hadron Facilities, held on 15-16 August at Los Alamos National Laboratory, several speakers pointed out that the US physics community carrying out fixed target experiments with hadron beam had not been as successful with funding as it deserved. To rectify this, they said, the community should be better organized and present a more united front

LOS ALAMOS: Hadron future

Energy Technology Data Exchange (ETDEWEB)

Ernst, David J.

1992-11-15

At a Workshop on the Future of Hadron Facilities, held on 15-16 August at Los Alamos National Laboratory, several speakers pointed out that the US physics community carrying out fixed target experiments with hadron beam had not been as successful with funding as it deserved. To rectify this, they said, the community should be better organized and present a more united front.

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

Meson-Meson molecules and compact four-quark states

International Nuclear Information System (INIS)

Vijande, J.; Valcarce, A.

2010-01-01

The physics of charm has become one of the best laboratories exposing the limitations of the naive constituent quark model and also giving hints into a more mature description of meson spectroscopy, beyond the simple quark-antiquark configurations. In this talk we review some recent studies of multiquark components in the charm sector and discuss in particular exotic and non-exotic four-quark systems.

Los Alamos Spheromak Program

International Nuclear Information System (INIS)

Knox, S.O.; Barnes, C.W.; Fernandez, J.C.

1985-01-01

The Los Alamos Spheromak Program consists of two experimental facilities. The confinement physics of sustained and decaying spheromaks are being studied in CTX, which has an extensive array of diagnostics. Experiments are directed towards extending the physics understanding of the spheromak as a magnetic confinement concept. Electrodes for the production of clean sustained spheromaks are developed on the Electrode Facility, which is more flexible in terms of experimental modifications. Improvements to helicity sources and elecrodes which are proven on the Electrode Facility are then considered for incorporation onto CTX

LAMPF II workshop, Los Alamos National Laboratory, Los Alamos, New Mexico, February 1-4, 1982

International Nuclear Information System (INIS)

Thiessen, H.A.

1982-01-01

This report contains the proceedings of the first LAMPF II Workshop held at Los Alamos February 1 to 4, 1982. Included are the talks that were available in written form. The conclusion of the participants was that there are many exciting areas of physics that will be addressed by such a machine

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.

Charged track multiplicity in B meson decay

International Nuclear Information System (INIS)

Brandenburg, G.; Ershov, A.; Gao, Y. S.; Kim, D. Y.-J.; Wilson, R.; Browder, T. E.; Li, Y.; Rodriguez, J. L.; Yamamoto, H.; Bergfeld, T.

2000-01-01

We have used the CLEO II detector to study the multiplicity of charged particles in the decays of B mesons produced at the Υ(4S) resonance. Using a sample of 1.5x10 6 B meson pairs, we find the mean inclusive charged particle multiplicity to be 10.71±0.02 -0.15 +0.21 for the decay of the pair. This corresponds to a mean multiplicity of 5.36±0.01 -0.08 +0.11 for a single B meson. Using the same data sample, we have also extracted the mean multiplicities in semileptonic and nonleptonic decays. We measure a mean of 7.82±0.05 -0.19 +0.21 charged particles per BB(bar sign) decay when both mesons decay semileptonically. When neither B meson decays semileptonically, we measure a mean charged particle multiplicity of 11.62±0.04 -0.18 +0.24 per BB(bar sign) pair. (c) 2000 The American Physical Society

A Sailor in the Los Alamos Navy

Energy Technology Data Exchange (ETDEWEB)

Judd, D. L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Meade, Roger Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States

2016-12-20

As part of the War Department’s Manhattan Engineer District (MED), Los Alamos was an Army installation during World War II, complete with a base commander and a brace of MPs. But it was a unique Army installation, having more civilian then military personnel. Even more unique was the work performed by the civilian population, work that required highly educated scientists and engineers. As the breadth, scope, and complexity of the Laboratory’s work increased, more and more technically educated and trained personnel were needed. But, the manpower needs of the nation’s war economy had created a shortage of such people. To meet its manpower needs, the MED scoured the ranks of the Army for anyone who had technical training and reassigned these men to its laboratories, including Los Alamos, as part of its Special Engineer Detachment (SED). Among the SEDs assigned to Los Alamos was Val Fitch, who was awarded the Nobel Prize in Physics in 1980. Another was Al Van Vessem, who helped stack the TNT for the 100 ton test, bolted together the Trinity device, and rode shotgun with the bomb has it was driven from Los Alamos to ground zero.

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

International Nuclear Information System (INIS)

Allred, J.C.

1985-04-01

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

Workshop on mesons and mesonic states up to slightly above 1 GeV/c2

International Nuclear Information System (INIS)

Oelert, W.; Sefzick, T.

1991-04-01

The new accelerator COSY-Juelich will provide protons with momenta up to 3.3 GeV/c. Thus an effective mass slightly above 1 GeV/c 2 can be produced in the pp-interaction. Employing higher mass targets also heavier mesons can be observed. The production of single mesons and of mesonic states with and without strangeness can be investgated at COSY. The structure of some mesons in the mass range of 950 McV/c 2 to 1020 MeV/c 2 is still not well understood. While the Φ(1020) at the upper limit of this range is believed to be of rahter pure santi s nature the content of the η'(958) meson at the lower limit of this range is still under discussion. New results suggest that what is called the f o meson (former notation S*) consists in reality of two close and narrow states; one of them being a santi s - quarks configuration while the other should be a flavour singlet which couples to ππ and Kanti K with similar strengths. Also the discussion on possible gluonium candidates is still alive. It is speculated that some of these mesons - till now supposed to have widths of 30 to 50 MeV/c 2 - could rather be an overlay of structures with much smaller widths. Another features of resonances in this region is their partial decay into the Kanti K channel if their actual mass is large enough. Strong decays in Kanti K could be a signal of a Kanti K 'molecular' nature of the resonance. In particular the atomic K + K - structure should exist. In order to have review of the physics related to these problems there was a workshop held on: MESONS and MESONIC STATES up to slightly above 1 GeV/c 2 at the ZEL - Forschungszentrum - Juelich February 19 to 20, 1990. The following contains copies of the shown transparencies and short write-ups as far as available. (orig.)

MESON AND DI-ELECTRON PRODUCTION WITH HADES

Czech Academy of Sciences Publication Activity Database

Frohlich, I.; Agakishiev, G.; Agodi, C.; Balanda, A.; Bellia, G.; Belver, D.; Belyaev, A.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Braun-Munzinger, P.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; Díaz, J.; Dohrmann, F.; Dybczak, A.; Eberl, T.; Fabbietti, L.; Fateev, O.; Finocchiaro, P.; Fonte, P.; Friese, J.; Galatyuk, T.; Garzón, J.A.; Gernhäuser, R.; Gil, A.; Gilardi, C.; Golubeva, M.; Gonzalez-Diaz, D.; Grosse, E.; Guber, F.; Heilmann, M.; Hennino, T.; Holzmann, R.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Kirschner, D.; Koenig, I.; Koenig, W.; Kolb, B.W.; Kotte, R.; Kozuch, A.; Krása, Antonín; Křížek, Filip; Krücken, R.; Kuhn, W.; Kugler, Andrej; Kurepin, A.; Lamas-Valverde, J.; Lang, S.; Lange, J.S.; Lapidus, K.; Lopes, L.; Maier, L.; Mangiarotti, A.; Marín, J.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Mishra, D.; Moriniére, E.; Mousa, J.; Muntz, C.; Naumann, L.; Novotny, R.; Otwinowski, J.; Pachmayer, Y.C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Cavalcanti, T.P.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Roy-Stephan, M.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Schmah, A.; Simon, R. S.; Sobolev, Yuri, G.; Spataro, S.; Spruck, B.; Strobele, H.; Stroth, J.; Sturm, C.; Sudol, M.; Tarantola, A.; Teilab, K.; Tlustý, Pavel; Traxler, M.; Trebacz, R.; Tsertos, H.; Veretenkin, I.; Wagner, Vladimír; Wen, H.; Wisniowski, M.; Wojcik, T.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Yu.; Zhou, P.; Zumbruch, P.

2009-01-01

Roč. 24, 2-3 (2009), s. 317-326 ISSN 0217-751X. [Conference MESON 2008. Jagiellonian Univ, Cracow, 06.06.2008-10.06.2008] R&D Projects: GA AV ČR IAA100480803; GA MŠk LC07050 Institutional research plan: CEZ:AV0Z10480505 Keywords : Mesons * di-electrons * resonances Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.941, year: 2009

CKM Phenomenology and B-mesons physics-present status and current issues

International Nuclear Information System (INIS)

Ali, A.

2004-01-01

We review the status of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and the CP-violating phases in the CKM-unitarity triangle. The emphasis in these lecture notes is on B-meson physics, through we also review the current status and issues in the light quark sector of this matrix. Selected applications of theoretical methods in QCD used in the interpretation of data are given and some of the issues restricting the theoretical precision on the CKM matrix elements discussed. The overall consistency of the CKM theory with the available data in flavour physics is impressive and we quantify this consistency. Current data also show some anomalies which, however, are not yet statistically significant. They are discussed briefly. some benchmark measurements that remain to be done in experiments at the B-factories and hadron colliders are listed. Together with the already achieved results, they will provide unprecedented test of the CKM theory and by the same token may lead to the discovery of new physics. (Author) 284 refs

Quantum field theory approaches to meson structure

International Nuclear Information System (INIS)

Branz, Tanja

2011-01-01

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 f 0 (980) and a 0 (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.

Quark-hadron duality in meson physics

International Nuclear Information System (INIS)

Anisovich, V.V.

1994-01-01

Quark hadron dualism is discussed, based on observing the changes in the quark model characteristics after the inclusion into hadron degrees of freedom. A standard version of the potential model is presented. The potential which is responsible for the formation of mesons may be divided into two pieces: a short-range part for distances about 0.3 - 0.5 fm and a long-range part at distances more than 1 fm. (R.P.). 5 refs., 2 figs

Quark-hadron duality in meson physics

Energy Technology Data Exchange (ETDEWEB)

Anisovich, V.V. [Petersburg Nuclear Physics Inst., Gatchina (Russian Federation)

1994-12-31

Quark hadron dualism is discussed, based on observing the changes in the quark model characteristics after the inclusion into hadron degrees of freedom. A standard version of the potential model is presented. The potential which is responsible for the formation of mesons may be divided into two pieces: a short-range part for distances about 0.3 - 0.5 fm and a long-range part at distances more than 1 fm. (R.P.). 5 refs., 2 figs.

Meson-meson scattering in lattice QED2+1

International Nuclear Information System (INIS)

Fiebig, H.R.; Woloshyn, R.M.

1993-01-01

Scattering phase shifts of a meson-meson system in staggered 3-dimensional lattice QED are computed. The main task of the simulation is to obtain a discrete set of two-body energy levels. These are extracted from a 4-point time correlation matrix and then used to obtain scattering phase shifts. The results for the l = 0 and l = 2 partial waves are consistent with short-range repulsion and intermediate-range attraction of the residual meson-meson interaction. (orig.)

The multi-disciplinary role of 'pion factories'

International Nuclear Information System (INIS)

Davies, J.D.; Batty, C.J.; Green, K.

1977-01-01

The multi-disciplinary role of intermediate energy proton accelerators in pure and applied nuclear physics is discussed with particular reference to the experimental programmes at LAMPF (Los Alamos Meson Physics Facility) and SIN (Swiss Institute for Nuclear Research, Zurich). (author)

Interference in Exclusive Vector Meson Production in Heavy-Ion Collisions

International Nuclear Information System (INIS)

Klein, Spencer R.; Nystrand, Joakim

2000-01-01

Vector mesons are produced copiously in peripheral relativistic heavy-ion collisions. Virtual photons from one ion can fluctuate into quark-antiquark pairs and scatter from the second ion, emerging as vector mesons. The emitter and target are indistinguishable, so emission from the two ions will interfere. Vector mesons have negative parity so the interference is destructive, reducing the production of mesons with small transverse momentum. The mesons are short lived, and decay before emission from the two ions can overlap. However, the decay-product wave functions overlap and interfere since they are produced in an entangled state, providing an example of the Einstein-Podolsky-Rosen paradox. (c) 2000 The American Physical Society

Meson-nucleus potentials and the search for meson-nucleus bound states

Science.gov (United States)

Metag, V.; Nanova, M.; Paryev, E. Ya.

2017-11-01

Recent experiments studying the meson-nucleus interaction to extract meson-nucleus potentials are reviewed. The real part of the potentials quantifies whether the interaction is attractive or repulsive while the imaginary part describes the meson absorption in nuclei. The review is focused on mesons which are sufficiently long-lived to potentially form meson-nucleus quasi-bound states. The presentation is confined to meson production off nuclei in photon-, pion-, proton-, and light-ion induced reactions and heavy-ion collisions at energies near the production threshold. Tools to extract the potential parameters are presented. In most cases, the real part of the potential is determined by comparing measured meson momentum distributions or excitation functions with collision model or transport model calculations. The imaginary part is extracted from transparency ratio measurements. Results on K+ ,K0 ,K- , η ,η‧ , ω, and ϕ mesons are presented and compared with theoretical predictions. The interaction of K+ and K0 mesons with nuclei is found to be weakly repulsive, while the K- , η ,η‧ , ω and ϕ meson-nucleus potentials are attractive, however, with widely different strengths. Because of meson absorption in the nuclear medium the imaginary parts of the meson-nucleus potentials are all negative, again with a large spread. An outlook on planned experiments in the charm sector is given. In view of the determined potential parameters, the criteria and chances for experimentally observing meson-nucleus quasi-bound states are discussed. The most promising candidates appear to be the η and η‧ mesons.

Meson production near threshold: physics implications and new technical challenges

Energy Technology Data Exchange (ETDEWEB)

Meyer, H.O. [Indiana Univ., Bloomington, IN (United States). Dept. of Physics

1995-02-01

Recently, the study of pion production in few-nucleon systems has been advanced considerably, mainly due to experiments using internal targets in stored, cooled beams. Experimental progress has inspired theoretical insights: from measurements close to threshold we have learned that an enhancement of the axial charge caused by heavy-meson exchange significantly contributes to pion production. The study of the production of pions, as well as heavier mesons, with stored polarized beams and polarized internal targets is likely to heave important consequences for our understanding of the nuclear force. (author). 42 refs, 11 figs.

Proceedings of the Los Alamos neutrino workshop

International Nuclear Information System (INIS)

Boehm, F.; Stephenson, G.J. Jr.

1982-08-01

A workshop on neutrino physics was held at Los Alamos from June 8 to 12, 1981. The material presented has been provided in part by the organizers, in part by the chairmen of the working sessions. Closing date for contributions was October 1981

Experiments in intermediate energy physics

International Nuclear Information System (INIS)

Dehnhard, D.

2003-01-01

Research in experimental nuclear physics was done from 1979 to 2002 primarily at intermediate energy facilities that provide pion, proton, and kaon beams. Particularly successful has been the work at the Los Alamos Meson Physics Facility (LAMPF) on unraveling the neutron and proton contributions to nuclear ground state and transition densities. This work was done on a wide variety of nuclei and with great detail on the carbon, oxygen, and helium isotopes. Some of the investigations involved the use of polarized targets which allowed the extraction of information on the spin-dependent part of the triangle-nucleon interaction. At the Indiana University Cyclotron Facility (IUCF) we studied proton-induced charge exchange reactions with results of importance to astrophysics and the nuclear few-body problem. During the first few years, the analysis of heavy-ion nucleus scattering data that had been taken prior to 1979 was completed. During the last few years we created hypernuclei by use of a kaon beam at Brookhaven National Laboratory (BNL) and an electron beam at Jefferson Laboratory (JLab). The data taken at BNL for a study of the non-mesonic weak decay of the A particle in a nucleus are still under analysis by our collaborators. The work at JLab resulted in the best resolution hypernuclear spectra measured thus far with magnetic spectrometers

Experiments in intermediate energy physics

Energy Technology Data Exchange (ETDEWEB)

Dehnhard, D.

2003-02-28

Research in experimental nuclear physics was done from 1979 to 2002 primarily at intermediate energy facilities that provide pion, proton, and kaon beams. Particularly successful has been the work at the Los Alamos Meson Physics Facility (LAMPF) on unraveling the neutron and proton contributions to nuclear ground state and transition densities. This work was done on a wide variety of nuclei and with great detail on the carbon, oxygen, and helium isotopes. Some of the investigations involved the use of polarized targets which allowed the extraction of information on the spin-dependent part of the triangle-nucleon interaction. At the Indiana University Cyclotron Facility (IUCF) we studied proton-induced charge exchange reactions with results of importance to astrophysics and the nuclear few-body problem. During the first few years, the analysis of heavy-ion nucleus scattering data that had been taken prior to 1979 was completed. During the last few years we created hypernuclei by use of a kaon beam at Brookhaven National Laboratory (BNL) and an electron beam at Jefferson Laboratory (JLab). The data taken at BNL for a study of the non-mesonic weak decay of the A particle in a nucleus are still under analysis by our collaborators. The work at JLab resulted in the best resolution hypernuclear spectra measured thus far with magnetic spectrometers.

Excited meson spectroscopy with two chirally improved quarks

Science.gov (United States)

Engel, G.; Lang, C. B.; Mohler, D.; Limmer, M.; Schäfer, A.

The excited isovector meson spectrum is explored using two chirally improved dynamical quarks. Seven ensembles, with pion masses down to \\approx 250 MeV are discussed and used for extrapolations to the physical point. Strange mesons are investigated using partially quenched s-quarks. Using the variational method, we extract excited states in several channels and most of the results are in good agreement with experiment.

Meson photoproduction (CLAS)

Energy Technology Data Exchange (ETDEWEB)

Steffen Strauch

2009-10-01

This is a brief and selective discussion of meson photoproduction measurements with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Meson photo- production is being used as a tool for various investigations, including the spectroscopy of baryons and mesons and the search for vector-meson medium modifications.

Nonleptonic B decays involving tensor mesons

Energy Technology Data Exchange (ETDEWEB)

Lopez Castro, G. [Departamento de Fisica, Cinvestav del IPN, Apdo. Postal 14-740, 07000 Mexico, D.F. (Mexico); Munoz, J.H. [Departamento de Fisica, Cinvestav del IPN, Apdo. Postal 14-740, 07000 Mexico, D.F. (Mexico)]|[Departamento de Fisica, Universidad del Tolima, A.A. 546, Ibague (Colombia)

1997-05-01

Two-body nonleptonic decays of B mesons into PT and VT modes are calculated using the nonrelativistic quark model of Isgur {ital et al.} The predictions obtained for B{r_arrow}{pi}D{sub 2}{sup {asterisk}},{rho}D{sub 2}{sup {asterisk}} are a factor of 3{endash}5 below present experimental upper limits. Interesting patterns are obtained for ratios of B decays involving mesons with different spin excitations and their relevance for additional tests of forms factor models are briefly discussed. {copyright} {ital 1997} {ital The American Physical Society}

Discrete symmetries with neutral mesons

Science.gov (United States)

Bernabéu, José

2018-01-01

Symmetries, and Symmetry Breakings, in the Laws of Physics play a crucial role in Fundamental Science. Parity and Charge Conjugation Violations prompted the consideration of Chiral Fields in the construction of the Standard Model, whereas CP-Violation needed at least three families of Quarks leading to Flavour Physics. In this Lecture I discuss the Conceptual Basis and the present experimental results for a Direct Evidence of Separate Reversal-in-Time T, CP and CPT Genuine Asymmetries in Decaying Particles like Neutral Meson Transitions, using Quantum Entanglement and the Decay as a Filtering Measurement. The eight transitions associated to the Flavour-CP eigenstate decay products of entangled neutral mesons have demonstrated with impressive significance a separate evidence of TRV and CPV in Bd-physics, whereas a CPTV asymmetry shows a 2σ effect interpreted as an upper limit. Novel CPTV observables are discussed for K physics at KLOE-2, including the difference between the semileptonic asymmetries from KL and KS, the ratios of double decay rate Intensities to Flavour-CP eigenstate decay products and the ω-effect. Their observation would lead to a change of paradigm beyond Quantum Field Theory, however there is nothing in Quantum Mechanics forbidding CPTV.

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

International Nuclear Information System (INIS)

Allred, J.C.

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

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.

Precision electroweak physics with neutrinos at Los Alamos

International Nuclear Information System (INIS)

Sanders, G.H.

1989-01-01

We review the status of current efforts at Los Alamos to measure the mass of /bar /nu///sub e/ with tritium beta decay and to search for oscillation of /bar /nu///sub μ/ to /bar /nu///sub e/. A new proposal to carry out a precision measurement of the electroweak mixing angle, θ/sub W/, using neutrino-electron scattering measured in a 7000-ton water /hacek C/erenkov detector, the Large /hacek C/erenkov Detector (LCD), is described. 17 refs., 6 figs., 1 tab

Nucleon and meson beams of the JINR phasotron for fundamental and applied investigations

International Nuclear Information System (INIS)

Abazov, V.M.; Andreev, G.A.; Bragin, A.N.

1990-01-01

The paper throughly describes the medical beam lines and reports the results obtained in measurement of the physical and dosimetric characteristics of high energy neutron, meson and proton beams obtained at the JINR phasotron in the last three years. It is pointed out that for the present intensity of the extracted proton beam of the JINR phasotron 2.0-2.5 μA the meson beam intensities 10 3 s- 1 (π + -mesons) and 3x10 7 s -1 (π - -mesons) have been achieved with a wide-angle magnetic lens. These values correspond to the designed parameters of the facility 'F' meson beams for the extracted proton beam intensity planned to be 25 μA. Besides, a beam of so-called 'surface μ-muons (energy about 4 MeV) with the intensity 10 4 s -1 has been obtained. The achieved meason beam intensities make the possibilities of the JINR phasotron as high as those of small meson factories with the equivalent extracted proton beam current 20-25 μA and ensures progress both in meson physics studies and in fulfilment of some applied tasks. 20 refs.; 7 figs.; 8 tabs

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

International Nuclear Information System (INIS)

Allred, J.C.

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

Irradiation facilities at the Los Alamos Meson Physics Facility

International Nuclear Information System (INIS)

Sandberg, V.

1990-01-01

The irradiation facilities for testing SSC components and detector systems are described. Very high intensity proton, neutron, and pion fluxes are available with beam kinetic energies of up to 800 MeV. 4 refs., 12 figs., 2 tabs

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.

Los Alamos Opacities: Transition from LEDCOP to ATOMIC

International Nuclear Information System (INIS)

Magee, N.H.; Abdallah, J.; Colgan, J.; Hakel, P.; Kilcrease, D.P.; Mazevet, S.; Sherrill, M.; Fontes, C.J.; Zhang, H.L.

2004-01-01

This paper discusses the development of the ATOMIC code, a new low to mid Z opacity code, which will replace the current Los Alamos low Z opacity code LEDCOP. The ATOMIC code is based on the FINE code, long used by the Los Alamos group for spectral comparisons in local thermodynamic equilibrium (LTE) and for non-LTE calculations, utilizing the extensive databases from the atomic physics suite of codes based on the work of R. D. Cowan. Many of the plasma physics packages in LEDCOP, such as line broadening and free-free absorption, are being transferred to the new ATOMIC code. A new equation of state (EOS) model is being developed to allow higher density calculations than were possible with either the FINE or LEDCOP codes. Extensive modernization for both ATOMIC and the atomic physics code suites, including conversion to Fortran 90 and parallelization, are under way to speed up the calculations and to allow the use of expanded databases for both the LTE opacity tables and the non-LTE calculations. Future plans will be outlined, including considerations for new generation opacity tables

Meson decays in a quark model

International Nuclear Information System (INIS)

Roberts, W.; Silvestre-Brac, B.

1998-01-01

A recent model of hadron states is extended to include meson decays. We find that the overall success of the model is quite good. Possible improvements to the model are suggested. copyright 1997 The American Physical Society

Light meson decays from photon-induced reactions with CLAS

Energy Technology Data Exchange (ETDEWEB)

Kunkel, Michael C. [Forschungszentrum Juelich (Germany); Collaboration: CLAS-Collaboration

2015-07-01

Photo-production experiments with the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Laboratory produce data sets with unprecedented statistics of light mesons. With these data sets, measurements of transition form factors for η, ω, and η' via conversion decays are performed using a line shape analysis on the invariant mass of the final state dileptons. Tests of fundamental symmetries and information on the light quark mass difference are performed using a Dalitz plot analysis of the meson decay. In addition, the data allows for a search for dark matter, such as the heavy photon via conversion decays of light mesons and physics beyond the Standard Model is searched for via invisible decays of η mesons. An overview of the first results and future prospects is given.

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

Energy Technology Data Exchange (ETDEWEB)

Maiani, L. [Dipartimento di Fisica and INFN, ‘Sapienza’ Università di Roma, P.le Aldo Moro 5, I-00185 Roma (Italy); Polosa, A.D. [Dipartimento di Fisica and INFN, ‘Sapienza’ Università di Roma, P.le Aldo Moro 5, I-00185 Roma (Italy); CERN Theory Department, CH-1211 Geneva 23 (Switzerland); Riquer, V. [Dipartimento di Fisica and INFN, ‘Sapienza’ Università di Roma, P.le Aldo Moro 5, I-00185 Roma (Italy)

2016-06-27

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.

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

International Nuclear Information System (INIS)

Maiani, L.; Polosa, A.D.; 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.

Nuclear physics brought about by the π-mesons studied from field theory and experiments

International Nuclear Information System (INIS)

Toki, Hiroshi

2012-01-01

In nuclei π-mesons are playing key role. At first the important interactions of π-mesons in light nuclei is explained mentioning that the π-meson exchange force is tensor force. It is pointed out that the importance of π-meson is observed even in the deuterons. By the progress of computations it is possible at present to calculate nuclei up to the mass number of twelve. It is explained then how to handle the π-mesons in heavy nuclei referring to the discovery of the halo of 11 Li and its analysis. Due to the pseudo scalar properties of the π-mesons, tensor force is the strong nucleon-nucleon interaction. It has been necessary to go through numbers of trials and errors to arrive at the discovery of the proper tensor force analysis. It is shown to be possible to handle them in the Tensor-Optimized Shell Model (TOSM) based on the variation method. The explanation of the Extended Brueckner Hartree-Fock (EBHF) method obtained by combining the TOSM with the mean field theory used in the heavy nuclei is given. EBHF theory has the structure including high momentum components in the 2p2h wave functions. Calculated equation of state of symmetric nuclear matter is shown as a function of density in which important contribution of the tensor force is observed. Properties of nuclear matter are discussed. (S. Funahashi)

Nucleon-nucleon scattering at LAMPF and KEK

International Nuclear Information System (INIS)

Glass, G.

1988-01-01

A review of current measurements of spin-dependent observables in p-p and n-p scattering is given for experiments done at two laboratories, Clinton P. Anderson Meson Physics Facility at Los Alamos (LAMPF) and the National Laboratory for High Energy Physics in Japan (KEK). 18 refs., 12 figs

Meson-induced correlations of nucleons in nuclear Compton scattering

International Nuclear Information System (INIS)

Huett, M.; Milstein, A.I.

1998-01-01

The nonresonant (seagull) contribution to the nuclear Compton amplitude at low energies is strongly influenced by nucleon correlations arising from meson exchange. We study this problem in a modified Fermi gas model, where nuclear correlation functions are obtained with the help of perturbation theory. The dependence of the mesonic seagull amplitude on the nuclear radius is investigated and the influence of a realistic nuclear density on this amplitude is discussed. We found that different form factors appear for the static part (proportional to the enhancement constant κ) of the mesonic seagull amplitude and for the parts, which contain the contribution from electromagnetic polarizabilities. copyright 1998 The American Physical Society

Test of scalar meson structure in φ radiative decays

International Nuclear Information System (INIS)

Kumano, S.

1992-12-01

We show that φ radiative decays into scalar mesons [f 0 (975), a 0 (980) ≡ S] can provide important clues on the internal structures of these mesons. Radiative decay widths vary widely: B.R. = 10 -4 -10 -6 depending on the substructures (qq-bar, qqq-barq-bar, KK-bar, glueball). Hence, we could discriminate among various models by measuring these widths at future φ factories. The understanding of these meson structures is valuable not only in hadron spectroscopy but also in nuclear physics in connection with the widely-used but little-understood σ meson. We also find that the decay φ→S γ →K 0 K-bar 0 γ is not strong enough to pose a significant background problem for studying CP violation via φ→K 0 K-bar 0 at the φ factories. (author)

Modified quark-meson coupling model for nuclear matter

International Nuclear Information System (INIS)

Jin, X.; Jennings, B.K.

1996-01-01

The quark-meson coupling model for nuclear matter, which describes nuclear matter as nonoverlapping MIT bags bound by the self-consistent exchange of scalar and vector mesons, is modified by introducing medium modification of the bag constant. We model the density dependence of the bag constant in two different ways: One invokes a direct coupling of the bag constant to the scalar meson field, and the other relates the bag constant to the in-medium nucleon mass. Both models feature a decreasing bag constant with increasing density. We find that when the bag constant is significantly reduced in nuclear medium with respect to its free-space value, large canceling isoscalar Lorentz scalar and vector potentials for the nucleon in nuclear matter emerge naturally. Such potentials are comparable to those suggested by relativistic nuclear phenomenology and finite-density QCD sum rules. This suggests that the reduction of bag constant in nuclear medium may play an important role in low- and medium-energy nuclear physics. copyright 1996 The American Physical Society

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.

ω(→ π+π−π0) meson photoproduction on proton

Indian Academy of Sciences (India)

PRAMANA c Indian Academy of Sciences. Vol. 75, No. 4. — journal of. October 2010 physics pp. 665–674 ω(→ π+π−π0) meson photoproduction on proton ... The vector meson can probe the low-lying nucleonic resonances [7] because it ... reaction amplitudes from the latest measurement of the four-momentum transfer.

Overview of LAMPF and its accomplishments

International Nuclear Information System (INIS)

Rosen, L.

1978-04-01

The report presented is from a talk given at a Los Alamos Scientific Laboratory colloquium on October 4, 1977, in which the history, technological accomplishments, present status, and scientific program at the Clinton P. Anderson Meson Physics Facility (LAMPF) were reviewed

Universal behavior in excited heavy-light and light-light mesons

International Nuclear Information System (INIS)

Olsson, M.G.

1997-01-01

A common pattern of large orbital and radial excitations in heavy-light and light-light mesons is demonstrated. For a general potential model with linear confinement the Regge slopes of the light degrees of freedom for these mesons are shown to be in the ratio of 2. The possibility of 'tower' degeneracy occurs only with pure scalar confinement. copyright 1997 The American Physical Society

Compton scattering, meson exchange, and the polarizabilities of bound nucleons

International Nuclear Information System (INIS)

Feldman, G.; Mellendorf, K.E.; Eisenstein, R.A.; Federspiel, F.J.; Garino, G.; Igarashi, R.; Kolb, N.R.; Lucas, M.A.; MacGibbon, B.E.; Mize, W.K.; Nathan, A.M.; Pywell, R.E.; Wells, D.P.

1996-01-01

Elastic photon scattering cross sections on 16 O have been measured in the energy range 27 endash 108 MeV. These data are inconsistent with a conventional interpretation in which the electric and magnetic polarizabilities of the bound nucleon are unchanged from the free values and the meson-exchange seagull amplitude is taken in the zero-energy limit. Agreement with the data can be achieved by invoking either strongly modified polarizabilities or a substantial energy dependence to the meson-exchange seagull amplitude. It is argued that these seemingly different explanations are experimentally indistinguishable and probably physically equivalent. copyright 1996 The American Physical Society

Spectrum-generating SU(4) in particle physics. II. Electromagnetic decays of vector mesons

International Nuclear Information System (INIS)

Bohm, A.; Teese, R.B.

1977-09-01

The decay rates for the electromagnetic decays of vector mesons are derived within the spectrum-generating SU(4) approach. Radiative as well as leptonic decays of vector mesons can be derived from one theoretical assumption and given in terms of three reduced matrix elements. The implication of the experimental value GAMMA(rho → πγ) = (35 +- 10) keV for the form of the electromagnetic current operator is discussed

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.

Measurement of Charm Meson Lifetimes

International Nuclear Information System (INIS)

Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J.; Chan, S.; Eigen, G.; Lipeles, E.; Schmidtler, M.; Shapiro, A.; Sun, W.M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F.; Jaffe, D.E.; Masek, G.; Paar, H.P.; Potter, E.M.; Prell, S.; Sharma, V.; Asner, D.M.; Eppich, A.; Gronberg, J.; Hill, T.S.; Korte, C.M.; Lange, D.J.; Morrison, R.J.; Nelson, H.N.; Nelson, T.K.; Roberts, D.; Tajima, H.; Behrens, B.H.; Ford, W.T.; Gritsan, A.; Krieg, H.; Roy, J.; Smith, J.G.; Alexander, J.P.; Baker, R.; Bebek, C.; Berger, B.E.; Berkelman, K.; Boisvert, V.; Cassel, D.G.; Crowcroft, D.S.; Dickson, M.; Dombrowski, S. von; Drell, P.S.; Dumas, D.J.; Ecklund, K.M.; Ehrlich, R.; Foland, A.D.; Gaidarev, P.; Gibbons, L.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Hopman, P.I.; Katayama, N.; Kreinick, D.L.; Lee, T.; Liu, Y.; Meyer, T.O.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Ogg, M.; Patterson, J.R.; Peterson, D.; Riley, D.; Soffer, A.; Thayer, J.G.; Thies, P.G.; Valant-Spaight, B.; Warburton, A.; Ward, C.; Athanas, M.; Avery, P.; Jones, C.D.; Lohner, M.; Prescott, C.; Rubiera, A.I.; Yelton, J.; Zheng, J.; Brandenburg, G.; Briere, R.A.; Ershov, A.; Gao, Y.S.; Kim, D.Y.; Wilson, R.; Browder, T.E.; Li, Y.; Rodriguez, J.L.; Yamamoto, H.; Bergfeld, T.; Eisenstein, B.I.; Ernst, J.; Gladding, G.E.; Gollin, G.D

1999-01-01

We report measurements of the D 0 , D + , and D + s meson lifetimes using 3.7 fb -1 of e + e - annihilation data collected near the Υ(4S) resonance with the CLEO detector. The measured lifetimes of the D 0 , D + , and D + s mesons are 408.5±4.1 +3.5 -3.4 fs , 1033.6±22.1 +9.9 -12.7 fs , and 486.3±15.0 +4.9 -5.1 fs . The precision of these lifetimes are comparable to those of the best previous measurements, and the systematic errors are very different. In a single experiment we find that the ratio of the D + s and D 0 lifetimes is 1.19±0.04 . copyright 1999 The American Physical Society

Technical progress report

International Nuclear Information System (INIS)

1982-01-01

This report summarizes the work carried out by personnel at the Nuclear Physics Laboratory of the University of Colorado from about August 1, 1981 to October 1, 1982, under contract with the Department of Energy. The intermediate energy studies summarized in this report were carried out at the meson physics facilities at Los Alamos (LAMPF), the cyclotron at Indiana University (IUCF), and the meson physics facilities at Vancouver (TRIUMF). This year, for the first time, intermediate energy experimental studies are being reported in separate documents from the low energy and theoretical nuclear physics efforts. Experimental studies are reported on pion-nucleus interactions, charge exchange reactions, nucleon transfer reactions, and apparatus development

Temperature-dependent cross sections for meson-meson nonresonant reactions in hadronic matter

International Nuclear Information System (INIS)

Zhang Yiping; Xu Xiaoming; Ge Huijun

2010-01-01

We present a potential of which the short-distance part is given by one gluon exchange plus perturbative one- and two-loop corrections and of which the large-distance part exhibits a temperature-dependent constant value. The Schroedinger equation with this temperature-dependent potential yields a temperature dependence of the mesonic quark-antiquark relative-motion wave function and of meson masses. The temperature dependence of the potential, the wave function and the meson masses brings about temperature dependence of cross sections for the nonresonant reactions ππ→ρρ for I=2, KK→K*K* for I=1, KK*→K*K* for I=1, πK→ρK* for I=3/2, πK*→ρK* for I=3/2, ρK→ρK* for I=3/2 and πK*→ρK for I=3/2. As the temperature increases, the rise or fall of peak cross sections is determined by the increased radii of initial mesons, the loosened bound states of final mesons, and the total-mass difference of the initial and final mesons. The temperature-dependent cross sections and meson masses are parametrized.

Search for Neutrinoless τ Decays Involving π0 or η Mesons

International Nuclear Information System (INIS)

Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J.; Barish, B.; Chadha, M.; Chan, S.; Eigen, G.; Miller, J.S.; OGrady, C.; Schmidtler, M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F.; Asner, D.M.; Bliss, D.W.; Brower, W.S.; Masek, G.; Paar, H.P.; Prell, S.; Sharma, V.; Gronberg, J.; Hill, T.S.; Kutschke, R.; Lange, D.J.; Menary, S.; Morrison, R.J.; Nelson, H.N.; Nelson, T.K.; Qiao, C.; Richman, J.D.; Roberts, D.; Ryd, A.; Witherell, M.S.; Balest, R.; Behrens, B.H.; Cho, K.; Ford, W.T.; Park, H.; Rankin, P.; Roy, J.; Smith, J.G.; Alexander, J.P.; Bebek, C.; Berger, B.E.; Berkelman, K.; Bloom, K.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Crowcroft, D.S.; Dickson, M.; Drell, P.S.; Ecklund, K.M.; Ehrlich, R.; Elia, R.; Foland, A.D.; Gaidarev, P.; Galik, R.S.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Hopman, P.I.; Kandaswamy, J.; Kim, P.C.; Kreinick, D.L.; Lee, T.; Liu, Y.; Ludwig, G.S.; Masui, J.; Mevissen, J.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Ogg, M.; Patterson, J.R.; Peterson, D.; Riley, D.; Soffer, A.; Valant-Spaight, B.; Ward, C.; Athanas, M.; Avery, P.; Jones, C.D.; Lohner, M.; Prescott, C.; Yelton, J.; Zheng, J.; Brandenburg, G.; Briere, R.A.; Gao, Y.S.; Kim, D.Y.; Wilson, R.; Yamamoto, H.; Browder, T.E.; Li, F.; Li, Y.; Rodriguez, J.L.; Bergfeld, T.; Eisenstein, B.I.; Ernst, J.

1997-01-01

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 π 0 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

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)

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

International Nuclear Information System (INIS)

Lehner, F.; Faverot-Spengler, S.

2007-11-01

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)

Publications of Los Alamos Research, 1977-1981: formerly Publications of LASL Research. Volume II

International Nuclear Information System (INIS)

Sheridan, C.J.; Garcia, C.A.

1983-03-01

This volume is a bibliography of Los Alamos publications during the specified period in the following areas: general physics; nuclear physics; particles and fields; radioisotope and radiation applications; nuclear materials security safeguards; solar energy; theoretical plasma physics; and transportation of property and nuclear materials

Angular Momentum Content of the ρ Meson in Lattice QCD

International Nuclear Information System (INIS)

Glozman, Leonid Ya.; Lang, C. B.; Limmer, Markus

2009-01-01

The variational method allows one to study the mixing of interpolators with different chiral transformation properties in the nonperturbatively determined physical state. It is then possible to define and calculate in a gauge-invariant manner the chiral as well as the partial wave content of the quark-antiquark component of a meson in the infrared, where mass is generated. Using a unitary transformation from the chiral basis to the 2S+1 L J basis one may extract a partial wave content of a meson. We present results for the ground state of the ρ meson using quenched simulations as well as simulations with n f =2 dynamical quarks, all for lattice spacings close to 0.15 fm. We point out that these results indicate a simple 3 S 1 -wave composition of the ρ meson in the infrared, like in the SU(6) flavor-spin quark model.

Angular Momentum Content of the ρ Meson in Lattice QCD

Science.gov (United States)

Glozman, Leonid Ya.; Lang, C. B.; Limmer, Markus

2009-09-01

The variational method allows one to study the mixing of interpolators with different chiral transformation properties in the nonperturbatively determined physical state. It is then possible to define and calculate in a gauge-invariant manner the chiral as well as the partial wave content of the quark-antiquark component of a meson in the infrared, where mass is generated. Using a unitary transformation from the chiral basis to the LJ2S+1 basis one may extract a partial wave content of a meson. We present results for the ground state of the ρ meson using quenched simulations as well as simulations with nf=2 dynamical quarks, all for lattice spacings close to 0.15 fm. We point out that these results indicate a simple S13-wave composition of the ρ meson in the infrared, like in the SU(6) flavor-spin quark model.

MesonNet Workshop on Meson Transition Form Factors

CERN Document Server

Eidelman, S; Hanhart, C; Kubis, B; Kupsc, A; Leupold, S; Moskal, P; Schadmand, S

2012-01-01

The mini-proceedings of the Workshop on Meson Transition Form Factors held in Cracow from May 29th to 30th, 2012 introduce the meson transition form factor project with special emphasis on the interrelations between the various form factors (on-shell, single off-shell, double off-shell). Short summaries of the talks presented at the workshop follow.

High energy neutron dosimetry for the fusion program

International Nuclear Information System (INIS)

Barr, D.W.; Norris, A.E.

1977-01-01

Neutron dosimetry by the foil activation method offers a flexible technique for characterizing neutron spectra ranging from thermal energies to 30 MeV with the potential for extension to higher neutron energies as investigated by the Los Alamos Radiochemistry Group at the Los Alamos Meson Physics Facility and in the Apollo-Soyuz Test Project. The use of this method for the neutron flux description in thermal, resonance, and fission spectrum assemblies has been demonstrated. An extension of the method to environments involving thermonuclear processes was developed at Los Alamos in the early 1950's to characterize mixed fission-thermonuclear systems

Meson Spectroscopy in the Light Quark Sector

Science.gov (United States)

De Vita, R.

2014-03-01

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 qbar q configuration as tetraquarks (qqoverline{qq}), hybrids (qbar qg) 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 qbar q 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, pbar p annihilation, pion scattering, proton-proton scattering and photo-production, to produce meson states. This intense effort is

Holographic estimate of the meson cloud contribution to nucleon axial form factor

Science.gov (United States)

Ramalho, G.

2018-04-01

We use light-front holography to estimate the valence quark and the meson cloud contributions to the nucleon axial form factor. The free couplings of the holographic model are determined by the empirical data and by the information extracted from lattice QCD. The holographic model provides a good description of the empirical data when we consider a meson cloud mixture of about 30% in the physical nucleon state. The estimate of the valence quark contribution to the nucleon axial form factor compares well with the lattice QCD data for small pion masses. Our estimate of the meson cloud contribution to the nucleon axial form factor has a slower falloff with the square momentum transfer compared to typical estimates from quark models with meson cloud dressing.

DOE R and D data tracking base

International Nuclear Information System (INIS)

Horpedahl, L.; Brooks, M.

2000-01-01

This document consists of DOE R and D tracking information for the following topics: Stockpile Readiness Program; Stockpile Reduction Program; Enduring Stockpile Program; Future Stockpile Program; Archiving; Nuclear Component Assessment; Advanced Application; Validation and Verification; Distance and Distributed Computing; DOD Munitions; Performance Assessment; Physics; Los Alamos Meson Physics Facility/Los Alamos Neutron Science Center; Advanced Hydrodynamic Radiography; Systems Engineering; Advanced Manufacturing; Chemistry and Materials; High Explosives; Special Nuclear Mateirals; Tritium; Collaboration with ASCI; Numeric Environment for Weapons Simulation; Target Physics; Theory and Modeling; Target Development; Fabrication and Handling; Other ICF Activities; Development of Predictive Capabilities--Nuclear; Development of Diagnostic Tools--Nuclear; Process Development; and IPPD/Agile Manufacturing

Los Alamos Climatology 2016 Update

Energy Technology Data Exchange (ETDEWEB)

Bruggeman, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-02-10

The Los Alamos National Laboratory (LANL or the Laboratory) operates a meteorology monitoring network to support LANL emergency response, engineering designs, environmental compliance, environmental assessments, safety evaluations, weather forecasting, environmental monitoring, research programs, and environmental restoration. Weather data has been collected in Los Alamos since 1910. Bowen (1990) provided climate statistics (temperature and precipitation) for the 1961– 1990 averaging period, and included other analyses (e.g., wind and relative humidity) based on the available station locations and time periods. This report provides an update to the 1990 publication Los Alamos Climatology (Bowen 1990).

Search for New Physics in Rare and Semi-Rare Decays of B- Mesons in ATLAS

CERN Document Server

Ibragimov, Iskander; 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. The properties of the decay of the Bd meson into K*mu+ mu- are also sensitive to the presence of New Physics in loops and has received renewed interest because of possible deviations from the standard model in this decay observed by LHCb. We present recent results obtained by ATLAS, concerning the angular distribution parameters FL, S_i and P’_i in the region Q^2(mu+mu-)<6 GeV^2.

Los Alamos offers Fellowships

Science.gov (United States)

Los Alamos National Laboratory in New Mexico is calling for applications for postdoctoral appointments and research fellowships. The positions are available in geoscience as well as other scientific disciplines.The laboratory, which is operated by the University of California for the Department of Energy, awards J. Robert Oppenheimer Research Fellowships to scientists that either have or will soon complete doctoral degrees. The appointments are for two years, are renewable for a third year, and carry a stipend of $51,865 per year. Potential applicants should send a resume or employment application and a statement of research goals to Carol M. Rich, Div. 89, Human Resources Development Division, MS P290, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 by mid-November.

Composite mesons in self-confining chiral solitons

International Nuclear Information System (INIS)

Tandy, P.C.; Frank, M.R.

1991-01-01

Most quark-meson models for formation of a baryon as a bag or soliton solution begin with elementary local meson fields including a classical scalar configuration that provides repulsion of valence quarks from the vacuum. This presentation explores aspects of the very different formation mechanism that operates in a model where chiral effective meson fields are composite objects generated from bilocal qq-bar fluctuation fields and the dynamical quark mass can be self-confining. The focus is on the dynamical self-energy for quarks and the related distributed vertex for quark meson coupling. Initial numerical work to explore the practical consequences of these features is presented in the context of a static mean-field soliton. The particular method employed to identify the energy functional at the mean field or Hartree level is to obtain the standard effective action from the Legendre transformation with the help of a chemical potential constraint for the baryon number. The purpose of this approach is two-fold. First, a possible future consideration of radiative corrections might be undertaken by systematically continuing with the loop expansion beyond the lowest level. A second, more practical reason, is that in the presence of a general space-time dependent dynamical self-energy for quarks there are wavefunction renormalisation effects and energy self-consistencies to be defined and maintained for the valence quark states and eigenvalues. Speculations are made on whether this point of view can motivate meson-nucleon relativistic field models containing intrinsic cutoffs for use in nuclear physics. 29 refs., 5 figs

Observation of the weak time’s arrow in B mesons

CERN Multimedia

CERN. Geneva

2012-01-01

The mechanism of CP violation in weak interactions, as arising from the single physical phase in the CKM matrix, has been validated by more than a decade of intense experimental work probing CP violation, particularly with studies with B mesons. Since the Standard Model theory is CPT invariant, it predicts a “weak arrow of time” matching the large observed matter-antimatter asymmetry in B mesons. However, until recently there has been no direct observation of the expected, large time reversal (T) asymmetry. In this seminar we shall discuss how the BABAR experiment at SLAC has conducted a new data analysis where the decays of entangled neutral B mesons allow comparisons between the rates of four different transitions and their inverse, as a function of the time evolution of the B meson. The results lead to the first high significance, direct observation of T non-invariance through the exchange of initial and final states in transitions that can only be connected by a T symmetry transformation.

Measurements of the $B$ meson production cross-sections at LHCb

CERN Document Server

LIU, Bo; ROBBE, Patrick; HE, Jibo

Quantum Chromodynamics (QCD), one of the most fundamental components of the Standard Model theory of Particle Physics, is dedicated to describe the strong interactions among quarks and gluons. For the $B$ meson production cross-sections in hadron-hadron collisions, perturbative QCD (pQCD) calculations are available at next-to-leading order (NLO) and with the fixed-order plus next-to-leading logarithms (FONLL) approximations. Measuring $B$ meson production cross-sections at the Large Hadron Collider (LHC) is of great importance to test the pQCD calculations. The LHCb detector is a single-arm forward spectrometer. It collects the physical information of the products in proton-proton collisions at the LHC. The differential and total production cross-sections of $B$ mesons (including $B^+$, $B^0$ and $B_s^0$) in proton-proton collisions at $\\sqrt{s}=7\\,{\\rm TeV}$ are studied using 35${\\rm pb}^{-1}$ of data in 2010 and 370${\\rm pb}^{-1}$ of data in 2011 collected by the LHCb detector, and reported in this dissert...

Non prompt D-meson measurements with ALICE at the LHC

International Nuclear Information System (INIS)

Mazzilli, Marianna

2016-01-01

The production of hadrons with open heavy flavour (charm and beauty) in high-energy nucleus-nucleus collisions is a powerful tool to study the properties of the deconfined phase of strongly interacting matter known as the Quark-Gluon Plasma (QGP). The production of charm and beauty quarks occurs in hard partonic scattering processes in the early stage of the collisions. ALICE is the LHC experiment devoted to the study of heavy-ion physics. It is able to reconstruct charmed mesons in exclusive decays (e.g. D"0→K"−π"+) and beauty hadrons in semi-inclusive decays (e.g. B→eX, B→J/ψ X) . At LHC energies a significant component of the inclusive D-meson yield originates from the decay of beauty-flavoured hadrons, whose knowledge is essential to determine the production of prompt D mesons coming from charm quarks. A precise determination of the non-prompt fraction combined with the determination of the inclusive D-meson yield would allow a measurement of beauty production. A data-driven method that exploits the different shapes of the distributions of the transverse-plane impact parameter to the primary vertex of prompt and feed-down D mesons in p-Pb collisions is used in ALICE. An alternative approach based on the D-meson decay length for Pb–Pb collisions is under study.

Cabibbo-Kobayashi-Maskawa-favored B decays to a scalar meson and a D meson

Energy Technology Data Exchange (ETDEWEB)

Zou, Zhi-Tian; Li, Ying [Yantai University, Department of Physics, Yantai (China); Liu, Xin [Jiangsu Normal University, School of Physics and Electronic Engineering, Xuzhou (China)

2017-12-15

In this work, we attempt to study the Cabibbo-Kobayashi-Maskawa-favored B → anti DS (''S'' denoting the scalar meson) decays within the perturbative QCD approach at the leading order and the leading power. Although the light scalar mesons are widely perceived as primarily the four-quark bound states, in practice it is hard for us to make quantitative predictions based on the four-quark picture for light scalars. Hence, we calculate the decays with light scalars in the two-quark model. For the decays with scalar mesons above 1 GeV, we have explored two possible scenarios, depending on whether the light scalars are treated as the lowest lying q anti q states or four-quark particles. In total, we calculated the branching fractions of 72 decay modes, and most of them are in the range 10{sup -4}-10{sup -7}, which are measurable in the on-going LHCb experiment and the forthcoming Belle-II experiment. Moreover, since in the standard model these decays occur only through tree operators and have no CP asymmetries, any deviation will be a signal of new physics beyond the standard model. Despite large uncertainties induced by nonperturbative parameters and corrections of high order and high power, our results and discussions will be useful for the on-going LHCb and the forthcoming Belle-II experiments. (orig.)

A theory of scalar mesons

International Nuclear Information System (INIS)

Hooft, G. t'; Isidori, G.; Maiani, L.; Polosa, A.D.; Riquer, V.

2008-01-01

We discuss the effect of the instanton induced, six-fermion effective Lagrangian on the decays of the lightest scalar mesons in the diquark-antidiquark picture. This addition allows for a remarkably good description of light scalar meson decays. The same effective Lagrangian produces a mixing of the lightest scalars with the positive parity qq-bar states. Comparing with previous work where the qq-bar mesons are identified with the nonet at 1200-1700 MeV, we find that the mixing required to fit the mass spectrum is in good agreement with the instanton coupling obtained from light scalar decays. A coherent picture of scalar mesons as a mixture of tetraquark states (dominating in the lightest mesons) and heavy qq-bar states (dominating in the heavier mesons) emerges

The Los Alamos primer

CERN Document Server

Serber, Robert

2018-01-01

Unabridged declassified value reproduction of The Los Alamos Primer by Robert Serber, in full color with all censor markings. This is the booklet given to new workers at Los Alamos during World War II, to catch them up on how to build a practical fission bomb. The Primer was driven by Robert Oppenheimer asking his protégé Robert Serber to summarize all knowledge and possible solutions known as of April 1943 in a series of lectures. Serber did such an excellent job that the notes from the series was turned into The Los Alamos Primer. Serber was known as an expert that bridged theory and reality, and so was also chosen to be one of the first Americans to enter Hiroshima and Nagasaki to assess the atomic damage in 1945.

Charmed meson production at LHCb

International Nuclear Information System (INIS)

Müller, Dominik

2016-01-01

Measurements of charm meson production are important tests for QCD predictions and LHCb is uniquely suited to perform these measurements in the forward region. This paper summarises recent charm meson production measurements performed by LHCb of J/ψ and open charm mesons and the associated production of ϒ and open charm mesons. The J/ψ and open charm meson measurements are performed with data recorded in Run 2 of the Large Hadron Collider. With proton-proton collisions at √s = 13 TeV, these open a new regime in which QCD predictions for charm meson production may be precisely tested. Furthermore, ratios of cross-sections at different centre-of-mass energies benefit of cancellation of both experimental and theoretical uncertainties, providing a new sensitive test of the QCD calculations. Measurements of ϒ and open charm meson associated production are performed using √s = 7 TeV and √s = 8 TeV data and constitute the first observation of this production channel.

Pseudoscalar decay constant of B and Bs mesons using Dirac formalism

International Nuclear Information System (INIS)

Vinodkumar, P.C.; Shah, Manan; Patel, Bhavin

2015-01-01

The pseudoscalar decay constants are of great interest since they enter as input in nonleptonic B q decays, in the hadronic matrix elements of B q - B¯ q mixing, and in the extraction of CKM matrix elements |V cb |, |V ub | from the leptonic decay widths of B mesons. In the ongoing quest for new effects in high-energy particle physics, flavour physics provides information complementary to that from the direct searches performed at ATLAS and CMS. There is no direct evidence for decay constant from experimental side. Recently, two approaches, QCD sum rules (QCDSR) and lattice QCD (LQCD) found the pseudoscalar decay constant of B and B s mesons

Exclusive semileptonic decays of charmed and b-flavored mesons

International Nuclear Information System (INIS)

Barik, N.; Tripathy, S.K.; Kar, S.; Dash, P.C.

1997-01-01

We investigate the exclusive semileptonic decays of (B,B s ;D,D s ) mesons into less heavy as well as light mesons in a field-theoretic framework based on the independent quark model with a confining potential in scalar-vector-harmonic form. With the recoil effect properly taken into account, the present model describes consistently the semileptonic decays of charmed and b-flavored mesons, agreeing well with the experimental data. The transition form factors in the heavy to heavy decays, in particular, comply with the heavy quark symmetry relations expected from HQET. The CKM parameters extracted in this formalism are close to the existing data. The model prediction also satisfies the Isgur-Wise relation connecting the form factors of the semileptonic (B→ρeν) and that of rare radiative decay (B→ργ). copyright 1997 The American Physical Society

High statistics inclusive phi-meson production at SPS energies

International Nuclear Information System (INIS)

Dijkstra, H.B.

1985-01-01

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 8x10 6 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.)

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.)

PROPERTIES OF THE $omega$ MESON

Energy Technology Data Exchange (ETDEWEB)

Shafer, J. B.; Murray, J. J.; Ferro-Luzzi, M.; Huwe, D. O.

1963-06-15

Properties of the omega meson were studied from the reaction K/sup -/ + p yields LAMBDA + omega in a 72-in. hydrogen bubble chamber. The momentum of the K/sup -/ mesons was 1.2 to 1.75 Bev/c. The mass of the omega meson is found to be 782 Mev with a width, predominated by three-meson( pi ) decay mode, estimated to be less than 4 Mev. Branching ratios for omega -meson decay into pi /sup +/ pi /sup -/ pi /sup o/, pi /sup o/ gamma , pi /sup +/ i/ sup -/, and e/sup +/e/sup -o/ were determined. (R.E.U.)

Physics, Computer Science and Mathematics Division annual report, January 1--December 31, 1976

International Nuclear Information System (INIS)

Lepore, J.V.

1977-01-01

This annual report of the Physics, Computer Science and Mathematics Division describes the scientific research and other work carried out within the Division during the calendar year 1976. The Division is concerned with work in experimental and theoretical physics, with computer science and applied mathematics, and with the operation of a computer center. The major physics research activity is in high-energy physics; a vigorous program is maintained in this pioneering field. The high-energy physics research program in the Division now focuses on experiments with e + e - colliding beams using advanced techniques and developments initiated and perfected at the Laboratory. The Division continues its work in medium energy physics, with experimental work carried out at the Bevatron and at the Los Alamos Pi-Meson Facility. Work in computer science and applied mathematics includes construction of data bases, computer graphics, computational physics and data analysis, mathematical modeling, and mathematical analysis of differential and integral equations resulting from physical problems. The computer center serves the Laboratory by constantly upgrading its facility and by providing day-to-day service. This report is descriptive in nature; references to detailed publications are given

Physics, Computer Science and Mathematics Division annual report, January 1--December 31, 1976

Energy Technology Data Exchange (ETDEWEB)

Lepore, J.V. (ed.)

1977-01-01

This annual report of the Physics, Computer Science and Mathematics Division describes the scientific research and other work carried out within the Division during the calendar year 1976. The Division is concerned with work in experimental and theoretical physics, with computer science and applied mathematics, and with the operation of a computer center. The major physics research activity is in high-energy physics; a vigorous program is maintained in this pioneering field. The high-energy physics research program in the Division now focuses on experiments with e/sup +/e/sup -/ colliding beams using advanced techniques and developments initiated and perfected at the Laboratory. The Division continues its work in medium energy physics, with experimental work carried out at the Bevatron and at the Los Alamos Pi-Meson Facility. Work in computer science and applied mathematics includes construction of data bases, computer graphics, computational physics and data analysis, mathematical modeling, and mathematical analysis of differential and integral equations resulting from physical problems. The computer center serves the Laboratory by constantly upgrading its facility and by providing day-to-day service. This report is descriptive in nature; references to detailed publications are given. (RWR)

Properties of the ρ meson in dense nuclear matter

International Nuclear Information System (INIS)

Herrmann, M.

1992-05-01

In order to reach a description of the ρ meson, which is in accordance with the principles of the gauge invariance of the electromagnetic interaction, the vector-dominance hypothesis, and the unitarity a model for the ρ meson in the vacuum is developed. Thereafter follows the calculation of the properties of the ρ meson in nuclear matter. First the connection between the spectral function of the ρ meson and the dilepton production rate for an equilibrium state is derived. Then the model for the pion in nuclear matter is described. Following approximations are applied: The description of the pion-baryon interaction pursues non-relativistically and both the width of the delta resonance and the short-range repulsive delta-nucleon interaction is neglected. The self-energy of the ρ meson in nuclear matter following from this description is formally derived from the requirement to couple the ρ meson to a conserved current. The corrections for the 3-point and 4-point vertex resulting from this are calculated and discussed. Thereafter the physical consequences of the changed self-energy of the ρ meson in nuclear matter are considered. By means of the spectral function it is shown that up to the two-fold of the ground-state density the position of the resonance is nearly not changed. At still higher densities the resonances is a little shifted to higher energies. In the range of an invariant mass of about 400 meV a strong increasement concentrated on a small range results. This is caused by coupling to a naked delta-hole state and a pion. Finally the possibilities are discussed to apply the results of this thesis to the prediction of experimental data. Thereby it is proved to be necessary to base on a simulation of the heavy ion reaction. (orig./HSI) [de

Multisensory experiments and data acquisition systems on the meson facilities

International Nuclear Information System (INIS)

Bystritskij, V.M.

2000-01-01

The paper describes some of the multisensory experiments performed or being performed at the meson factories PSI (Switzerland), TRIUMF (Canada), LAMPF (USA), KEK (Japan), RAL (England) in order to investigate the fundamental processes in elementary particle physics. Designs of various detectors are briefly reviewed, the organizational ideology and the structure of the recording electronics and data acquisition systems for these experiments are considered. The ideology underlying the off-line analysis software is touched upon and the most important results of the investigations at meson factories are given

Alternative space-time view of vector-meson dominance for virtual-photon--nucleus scattering

International Nuclear Information System (INIS)

Argyres, E.N.; Lam, C.S.

1977-01-01

We clarify the meaning of vector-meson dominance for virtual photons via a coupled-channel formalism, in which the photon can interact only by converting itself into a vector meson, the conversion occurring anywhere in space. We calculate the relative contributions of the different conversion regions, discuss their physical interpretation, and establish the equivalence of this approach to the usual treatment

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.

Issues in light meson spectroscopy: The case for meson spectroscopy at CEBAF

Energy Technology Data Exchange (ETDEWEB)

Godfrey, S. [Carleton Univ., Ottawa (Canada)

1994-04-01

The author reviews some outstanding issues in meson spectroscopy. The most important qualitative issue is whether hadrons with explicit gluonic degrees of freedom exist. To answer this question requires a much better understanding of conventional q{bar q} mesons. The author therefore begins by examining the status of conventional meson spectroscopy and how the situation can be improved. The expected properties of gluonic excitations are discussed with particular emphasis on hybrids to give guidance to experimental searches. Multiquark systems are commented upon as they are likely to be important in the mass region under study and will have to be understood better. In the final section the author discusses the opportunities that CEBAF can offer for the study of meson spectroscopy.

Investigation of Semileptonic {ital B} Meson Decays to {ital p} -Wave Charm Mesons

Energy Technology Data Exchange (ETDEWEB)

Anastassov, A.; Duboscq, J.E.; Fujino, D.; Gan, K.K.; Hart, T.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Spencer, M.B.; Sung, M.; Undrus, A.; Wanke, R.; Wolf, A.; Zoeller, M.M. [Ohio State University, Columbus, Ohio 43210 (United States); Nemati, B.; Richichi, S.J.; Ross, W.R.; Skubic, P. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Bishai, M.; Fast, J.; Hinson, J.W.; Menon, N.; Miller, D.H.; Shibata, E.I.; Shipsey, I.P.; Yurko, M. [Purdue University, West Lafayette, Indiana 47907 (United States); Glenn, S.; Johnson, S.D.; Kwon, Y.; Roberts, S.; Thorndike, E.H. [University of Rochester, Rochester, New York 14627 (United States); Jessop, C.P.; Lingel, K.; Marsiske, H.; Perl, M.L.; Savinov, V.; Ugolini, D.; Wang, R.; Zhou, X. [Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States); Coan, T.E.; Fadeyev, V.; Korolkov, I.; Maravin, Y.; Narsky, I.; Shelkov, V.; Staeck, J.; Stroynowski, R.; Volobouev, I.; Ye, J. [Southern Methodist University, Dallas, Texas 75275 (United States); Artuso, M.; Efimov, A.; Goldberg, M.; He, D.; Kopp, S.; Moneti, G.C.; Mountain, R.; Schuh, S.; Skwarnicki, T.; Stone, S.; Viehhauser, G.; Xing, X. [Syracuse University, Syracuse, New York 13244 (United States); Bartelt, J.; Csorna, S.E.; Jain, V.; McLean, K.W.; Marka, S. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Godang, R.; Kinoshita, K.; Lai, I.C.; Pomianowski, P.; Schrenk, S. [Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States); Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J. [Wayne State University, Detroit, Michigan 48202 (United States); Barish, B.; Chadha, M.; Chan, S.; Eigen, G.; Miller, J.S.; OGrady, C.; Schmidtler, M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F. [California Institute of Technology, Pasadena, California 91125 (United States); Bliss, D.W.; Masek, G.; Paar, H.P.; Prell, S.; Sharma, V. and others

1998-05-01

We have studied semileptonic B meson decays with a p -wave charm meson in the final state using 3.29{times}10{sup 6} B{ovr B} 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{sup {minus}}{r_arrow}D{sup 0}{sub 1} {ell}{sup {minus}}{ovr {nu}}{sub {ell}}) B(D{sup 0}{sub 1}{r_arrow}D{sup {asterisk}+} {pi}{sup {minus}})=(0.373{plus_minus}0.085{plus_minus} 0.052{plus_minus}0.024){percent} and an upper limit for B(B{sup {minus}}{r_arrow}D{sup {asterisk}0}{sub 2} {ell}{sup {minus}}{ovr {nu}}{sub {ell}}) B(D{sup {asterisk}0}{sub 2}{r_arrow}D{sup {asterisk}+ }{pi}{sup {minus}}){lt}0.16{percent} (90{percent} C.L.). Furthermore, we present the first measurement of the q{sup 2} spectrum for B{sup {minus}}{r_arrow}D{sup 0}{sub 1}{ell}{sup {minus}} {ovr {nu}}{sub {ell}} . {copyright} {ital 1998} {ital The American Physical Society}

Comparative distribution of plutonium in contaminated ecosystems at Oak Ridge, Tennessee, and Los Alamos, New Mexico

International Nuclear Information System (INIS)

Dahlman, R.C.; Garten, C.T. Jr.; Hakonson, T.E.

1980-01-01

The distribution of plutonium was compared in portions of forest ecosystems at Oak Ridge, TN, and Los Alamos, NM, which were contaminated by liquid effluents. Inventories of plutonium in soil at the two sites were generally similar, but a larger fraction of the plutonium was associated with biota at Los Alamos than at Oak Ridge. Most (99.7 to 99.9%) of the plutonium was present in the soil, and very little (0.1 to 0.3%) was in biotic components. Comparative differences in distributions within the two ecosystems appeared to be related to individual contamination histories and greater physical transport of plutonium in soil to biotic surfaces at Los Alamos

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)

Bednar, M.; Hron, J.

2001-01-01

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.)

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.

Are narrow mesons, baryons and dibaryons evidence for multiquark states?

International Nuclear Information System (INIS)

Tatischeff, B.; Yonnet, J.

2000-01-01

Several narrow structures have been progressively observed since the last fifteen years, in di-baryonic invariant mass spectra or in missing mass spectra. More recently, narrow structures were observed in baryonic and now in mesonic mass spectra. Since these small peaks appear at fixed masses, independently of the experiment, they are associated with real states. There is no room to explain these states within classical nuclear physics taking into account baryonic and mesonic degrees of freedom. An interpretation is proposed, which associate these narrow structures with two coloured quark clusters. (authors)

Overview of the Los Alamos National Laboratory Inertial Confinement Fusion Program

International Nuclear Information System (INIS)

Harris, D.B.

1991-01-01

The Los Alamos Inertial Confinement Fusion (ICF) Program is focused on preparing for a National Ignition Facility. Target physics research is addressing specific issues identified for the Ignition Facility target, and materials experts are developing target fabrication techniques necessary for the advanced targets. We are also working with Lawrence Livermore National Laboratory on the design of the National Ignition Facility target chamber. Los Alamos is also continuing to develop the KrF laser-fusion driver for ICF. We are modifying the Aurora laser to higher intensity and shorter pulses and are working with the Naval Research Laboratory on the development of the Nike KrF laser. 9 refs., 1 fig., 2 tabs

Critical Infrastructure Protection- Los Alamos National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Bofman, Ryan K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-02-24

Los Alamos National Laboratory (LANL) has been a key facet of Critical National Infrastructure since the nuclear bombing of Hiroshima exposed the nature of the Laboratory’s work in 1945. Common knowledge of the nature of sensitive information contained here presents a necessity to protect this critical infrastructure as a matter of national security. This protection occurs in multiple forms beginning with physical security, followed by cybersecurity, safeguarding of classified information, and concluded by the missions of the National Nuclear Security Administration.

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

International Nuclear Information System (INIS)

Clearwater, S.H.; Papcun, G.; Clark, D.A.

1985-01-01

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

After the Resistance: The Alamo Today

Centers for Disease Control (CDC) Podcasts

2014-09-23

Byron Breedlove reads his essay After the Resistance: The Alamo Today about the Alamo and emerging disease resistance.  Created: 9/23/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/20/2014.

Chiral Quark-Meson model of N and DELTA with vector mesons

International Nuclear Information System (INIS)

Broniowski, W.; Banerjee, M.K.

1985-10-01

Vector mesons rho, A 1 and ω are introduced in the Chiral Quark-Meson Theory (CQMT) of N and Δ. We propose a new viewpoint for developing CQMT from QCD at the mean-field level. The SU(2) x SU(2) chiral Lagrangian incorporates universal coupling. Accordingly, rho is coupled to the conserved isospin current, A to the partially conserved axial-vector current (PCAC), and ω to the conserved baryon current. As a result the only parameter of the model not directly related to experiment is the quark-pion coupling constant. A fully self-consistent mean-field solution to the model is found for fields in the hedgehog ansatz. The vector mesons play a very important role in the system. They contribute significantly to the values of observables and produce a high-quality fit to many data. The classical stability of the system with respect to hedgehog excitations is analyzed through the use of the Quark-Meson RPA equations (QMRPA)

Critical assembly: a technical history of Los Alamos during the Oppenheimer years, 1943-1945

International Nuclear Information System (INIS)

Hoddeson, Lillian; Henriksen, P.W.; Meade, R.A.; Westfall, Catherine.

1993-01-01

This book sets out the history of the technical developments at the Los Alamos Laboratory which produced the first atomic bombs. Based on both classified and unclassified material it looks at the methodology of the research at Los Alamos. The research and development which led to the implosion and gun weapons, the research that enabled physics, chemistry and metallurgy that enabled scientists to design the weapons and to conceive the idea of the thermonuclear bomb are all chronicled. The methodology of the 'big science' carried out in national laboratories is studied. (UK)

Critical assembly: a technical history of Los Alamos during the Oppenheimer years, 1943-1945

Energy Technology Data Exchange (ETDEWEB)

Hoddeson, Lillian; Henriksen, P.W.; Meade, R.A.; Westfall, Catherine.

1993-01-01

This book sets out the history of the technical developments at the Los Alamos Laboratory which produced the first atomic bombs. Based on both classified and unclassified material it looks at the methodology of the research at Los Alamos. The research and development which led to the implosion and gun weapons, the research that enabled physics, chemistry and metallurgy that enabled scientists to design the weapons and to conceive the idea of the thermonuclear bomb are all chronicled. The methodology of the 'big science' carried out in national laboratories is studied. (UK).

Exotic hybrid mesons in hard electroproduction

CERN Document Server

Anikin, I V; Szymanowski, L; Teryaev, O V; Wallon, S

2005-01-01

We estimate the sizeable cross section for deep exclusive electroproduction of an exotic $J^{PC}=1^{-+}$ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e. as $1/Q^2$. This is due to the non-vanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in $\\alpha_{S}$ and we explore the consequences of fixing the renormalization scale ambiguity through the BLM procedure. We study the particular case where the hybrid meson decays through a $\\pi\\eta $ meson pair. We discuss the $\\pi\\eta$ generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of $\\pi$ and $\\eta$ mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very ...

Making nuclei by using nuclear forces. Overwhelming power and difficulties of π mesons

International Nuclear Information System (INIS)

Toki, Hiroshi

2013-01-01

This paper is contributed to the planed title of 'Thirty Years History of The Playing Fields of Physics'. These thirty years are exactly the period while the author has devoted himself to the research and study of physics. The title is centered on the papers on experiments. He wishes, however, to write based on his experience as a theoretical physicist on the nuclear physics as it should be and in which direction to be developed. He would like to dedicate this paper to the late Professors M. Muraoka and K. Sugimoto of Osaka University. In the section 2 of 'Overwhelming Power and Difficulty of π Mesons', the fundamental pictures of '2.1 Start of the Yukawa's π Meson theory', '2.2 Mayer-Jensen's shell model', '2.3 Nambu's chiral symmetry and its spontaneous breaking' are introduced briefly. In the section 3 of 'Physics Lead by the Nuclear Forces Including π Mesons', the subsection '3.1 Phenomenological nuclear force' is taken up at first, then '3.2 Structure of D and tensor forces', '3.3 Structure of triton and three body forces', '3.4 Tensor forces in α-particles' and '3.5 Shell structure of light nuclei developed by the Argonne group' are explained successively. In section 4 of 'Tensor Best Fitting Shell-Model', problems on '4.1 Halo structure of 11 Li brought about by the tensor force' and '4.2 Strong tensor correlated Hartree-Fock theory' are explained. In section 5 of 'Nuclear Structure in the age of K computer', present and future view is given in '5.1 Nuclear forces described on Quantum Chromo Dynamics', '5.2 Present status of the nuclear structure derived on the lattice QCD', '5.3 Three-body forces created by π mesons' and '5.4 Role of K computer in nuclear physics'. In section 6 of 'Fusion of D', a new way to reconsider this problem as one of the nuclear physics is presented. In the final section 7 of 'Exciting Nuclear Physics' a short summary and memories of Professor Sugimoto are given. (S. Funahashi)

Meson spectroscopy at the Serpukhov accelerator

International Nuclear Information System (INIS)

Prokoshkin, Yu.D.

1987-01-01

At present meson spectroscopy is a dominating direction of experimental studies at the IHEP accelerator. The main attention is paid to the search and study of exotic meson states. This report presents some new results obtained recently at the IHEP accelerator. First, observation is made of a narrow 1750 MeV meson decays into ηη. Above |t| ∼ 0.2 (GeV-c) 2 (t: a square of 4-momentum transferred to a neutron), a clear narrow peak appears in Mηη mass spectrum at a mass of 1750 MeV. Second, 2.22 GeV narrow meson decaying into η'η is described. At present only premature conclusions have been obtained in this area and the situation with ζ is not clear. Third, a study is made on new exotic tensor meson χ(1810) decaying into 4π deg and ηη channels. The decay M deg → 4π deg is a very promissing instrument in search for exotic mesons. Next, G(1590)-meson as a scalar glueball is discussed. BR(G → 4π deg) has a large value, an independent evidence of the exotic nature of G(1590)-meson. Experimental data obtained on all essential decay channels of G(1590)-meson allows to give a selfconsistent description of its production and decay as the scalar glueball, a particle with the dominating gluon component. The final two parts deal with exotic vector meson C(1480) decaying into ψπ deg and observation of D(1285) → ψγ decay. (Nogami, K.)

Future perspective of meson spectroscopy studies at KEK-PS

International Nuclear Information System (INIS)

Tsuru, T.

1992-01-01

Physics of light-quark meson spectroscopy at present is simply reviewed and a direction of next generation experiment is investigated. A new charge and gamma spectrometer is proposed to push forward next generation physics at KEK-PS. It should have almost 4π acceptance for both charged particles and gamma's and have options of π/K separation and good π 0 /γ separation. (author)

Spin-zero mesons and current algebras

International Nuclear Information System (INIS)

Wellner, M.

1977-01-01

Large chiral algebras, using the f and d coefficients of SU(3) can be constructed with spin-1/2 baryons. Such algebras have been found useful in some previous investigations. This article examines under what conditions similar or identical current algebras may be realized with spin-0 mesons. A curious lack of analogy emerges between meson and baryon currents. Second-class currents, made of mesons, are required in some algebras. If meson and baryon currents are to satisfy the same extended SU(3) algebra, four meson nonets are needed, in terms of which we give an explicit construction for the currents

What Can We Learn from Hadronic and Radiative Decays of Light Mesons?

Science.gov (United States)

Kubis, Bastian

2013-04-01

Chiral perturbation theory offers a powerful tool for the investigation of light pseudoscalar mesons. It incorporates the fundamental symmetries of QCD, interrelates various processes, and allows to link these to the light quark masses. Its shortcomings lie in a limited energy range: the radius of convergence of the chiral expansion is confined to below resonance scales. Furthermore, the strongest consequences of chiral symmetry are manifest for pseudoscalars (pions, kaons, eta) only: vector mesons, e.g., have a severe impact in particular for reactions involving photons. In this talk, I advocate dispersions relations as another model-independent tool to extend the applicability range of chiral perturbation theory. They even allow to tackle the physics of vector mesons in a rigorous way. It will be shown how dispersive methods can be used to resum large rescattering effects, and to provide model-independent links between hadronic and radiative decay modes. Examples to be discussed will include decays of the eta meson, giving access to light-quark-mass ratios or allowing to test the chiral anomaly; and meson transition form factors, which have an important impact on the hadronic light-by-light-scattering contribution to the anomalous magnetic moment of the muon.

Electroproduction and photoproduction of vector mesons and generalized vector meson dominance

International Nuclear Information System (INIS)

Fraas, H.; Kuroda, M.

1977-05-01

Using generalized vector meson dominance, electro- and photoproduction of vector mesons is studied. The unnatural parity exchange part of ω(1.2) production is estimated to be about one fourth of that of ω-production. The off diagonal transition model suggests the suppression of diffractive rho(1.2) and ω(1.2) production. (orig.) [de

Deep electroproduction of exotic hybrid mesons

International Nuclear Information System (INIS)

Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

2004-01-01

We evaluate the leading order amplitude for the deep exclusive electroproduction of an exotic hybrid meson in the Bjorken regime. We show that, contrarily to naive expectation, this amplitude factorizes at the twist 2 level and thus scales like usual meson electroproduction when the virtual photon and the hybrid meson are longitudinally polarized. Exotic hybrid mesons may thus be studied in electroproduction experiments at JLAB, HERA (HERMES) or CERN (Compass)

Numerical study of the lattice meson form factor

International Nuclear Information System (INIS)

Woloshyn, R.M.; Kobos, A.M.

1986-01-01

The electric form factor of the pseudo-Goldstone meson (the generic pion) is calculated in quenched lattice quantum chromodynamics with SU(2) color. Charge radii are calculated for different values of the bare-quark mass. The results are in agreement with the physically reasonable expectation that heavier quarks have distributions of smaller radius

B-meson anomalies and Higgs physics in flavored U(1)' model

Science.gov (United States)

Bian, Ligong; Lee, Hyun Min; Park, Chan Beom

2018-04-01

We consider a simple extension of the Standard Model with flavor-dependent U(1)', that has been proposed to explain some of B-meson anomalies recently reported at LHCb. The U(1)' charge is chosen as a linear combination of anomaly-free B_3-L_3 and L_μ -L_τ . In this model, the flavor structure in the SM is restricted due to flavor-dependent U(1)' charges, in particular, quark mixings are induced by a small vacuum expectation value of the extra Higgs doublet. As a result, it is natural to get sizable flavor-violating Yukawa couplings of heavy Higgs bosons involving the bottom quark. In this article, we focus on the phenomenology of the Higgs sector of the model including extra Higgs doublet and singlet scalars. We impose various bounds on the extended Higgs sector from Higgs and electroweak precision data, B-meson mixings and decays as well as unitarity and stability bounds, then discuss the productions and decays of heavy Higgs bosons at the LHC.

Exotic hybrid mesons in hard electroproduction

International Nuclear Information System (INIS)

Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

2005-01-01

We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC =1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e., as 1/Q 2 . This is due to the nonvanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy-momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in α S and we explore the consequences of fixing the renormalization scale ambiguity through the Brodsky-Lepage-Mackenzie (BLM) procedure. We study the particular case where the hybrid meson decays through a πη meson pair. We discuss the πη generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of π and η mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very high energy, in the diffractive limit where a QCD Odderon exchange mechanism should dominate. The conclusion of our study is that hard electroproduction is a promising way to study exotic hybrid mesons, in particular, at JLAB, HERA (HERMES), or CERN (Compass)

Los Alamos racquetball contamination incident

International Nuclear Information System (INIS)

McAtee, J.L.; Stafford, R.G.; Dowdy, E.J.; Prestwood, R.J.

1985-01-01

Several employees of the Los Alamos Plutonium Facility were found to have low levels of radioactivity on their hands and clothing when they arrived for work one morning. The initial concern was that the stringent contamination or material controls at the facility had failed, and that one or more of the employees had either accidentally or intentionally removed plutonium from the Laboratory premises. Fortunately, however, an investigation revealed that the source of the radioactivity was radon daughters electrostatically collected upon the surface of the racquetball and transferred by physical contact to the employees during an early morning racquetball game. This paper describes the events leading to the discovery of this phenomenon. 1 figure

Studies of η' (ω) mesons with the crystal ball/TAPS setup at MAMI

Energy Technology Data Exchange (ETDEWEB)

Adlarson, Patrik [Institut fuer Kernphysik, Johannes Gutenberg Universitaet, Mainz (Germany); Collaboration: A2-Collaboration

2015-07-01

Precision studies of light meson decays are used to investigate a wide range of topics related to fundamental aspects of hadron physics. In particular, η' decays allow for tests of such diverse topics as ππ scattering lengths, the SU(3) singlet-octet mixing angle, quark mass differences and light-by-light contribution to the anomalous magnetic moment of the muon. Recently, a large statistics sample of η'(ω) mesons have been produced and collected with the Crystal Ball/TAPS setup at MAMI. An overview of the physics motivation, the experimental setup and preliminary results from the ongoing analyses are presented.

Underground science initiatives at Los Alamos

International Nuclear Information System (INIS)

Simmons, L.M. Jr.

1985-01-01

Recently, the Los Alamos National Laboratory has proposed two major new initiatives in underground science. Following the dissolution of the original gallium solar neutrino collaboration, Los Alamos has formed a new North American collaboration. We briefly review the rationale for solar neutrino research, outline the proposal and new Monte Carlo simulations, and describe the candidate locations for the experiment. Because there is no dedicated deep underground site in North America suitable for a wide range of experiments, Los Alamos has conducted a survey of possible sites and developed a proposal to create a new National Underground Science Facility. This paper also reviews that proposal

Nature of the light scalar mesons

International Nuclear Information System (INIS)

Vijande, J.; Valcarce, A.; Fernandez, F.; Silvestre-Brac, B.

2005-01-01

Despite the apparent simplicity of meson spectroscopy, light scalar mesons cannot be accommodated in the usual qq structure. We study the description of the scalar mesons below 2 GeV in terms of the mixing of a chiral nonet of tetraquarks with conventional qq states. A strong diquark-antidiquark component is found for several states. The consideration of a glueball as dictated by quenched lattice QCD drives a coherent picture of the isoscalar mesons

Quarks and mesons in nuclei

International Nuclear Information System (INIS)

Rho, M.

1981-01-01

Quantum chromodynamics is believed to be candidate theory for the strong interactions and contains as its ingredients spinor quark fields and vector gluons, none of which can perhaps be ever liberated and detected in laboratories. A nucleus consists of nucleons bound by nuclear force which are however separately observable and which seem to preserve their identities even under extreme conditions. An intriguing question is: when compressed to high densities or heated to high temperature, at what point does a nuclear matter cease to be describable in terms of nucleon and meson degrees of freedom, but become a plasma of quarks and gluons; and how does this transition occur. This is not an idle question. If quarks and gluons are never to be observed isolated, then it may be that at low energies (or at low densities) they are not the right variables to do physics with. Instead hadrons must be. On the other hand, asymptotic freedom - the unique property of non-abelian gauge theories to which QCD belongs that quark-gluon and gluon-gluon interactions get weaker at short distances - tells us that at some large matter density the matter must necessarily be in the form of quark gas interacting only weakly. This means that a change in degrees of freedom must take place. We would like to know where this occurs and how. In this talk, I would like to address to this question by discussing first the large success we have had in understanding the role that mesons play in finite nuclei and nuclear matter and then attempting to correlate nucleon and meson degrees of freedom to quark-gluon degrees of freedom. In my opinion we are now at a stage where we feel fairly confident in our understanding of nucleon-meson structure of nuclei and nuclear matter and any further progress in deeper understanding of nuclear dynamics - and strong interactions - must come from QCD or its effective version, bags or strings. (orig.)

Meson factories

International Nuclear Information System (INIS)

Dicello, J.F.; Zaider, M.; Bradbury, J.N.

1979-01-01

Technological improvements in accelerator design in the 1960's resulted in the capability to develop medium-energy proton accelerators with beam intensities of almost 1 mA. These beams are able to produce fluxes of secondary particles, including pions, muons, neutrinos, and neutrons, which are as much as 10,000 times as intense as those previously available. Those machines built for optimum meson production are commonly called meson factories. The characteristics of these facilities are reviewed, and the present programs in applied research, and some potential areas of future work are discussed

UC/Los Alamos Entrepreneurial Postdoctoral Fellowship Pilot Program

Energy Technology Data Exchange (ETDEWEB)

Johnston, Mariann R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clow, Shandra Deann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-03-06

The UC/Los Alamos Entrepreneurial Postdoctoral Fellowship Pilot Program (Pilot) for existing postdoctoral researchers at Los Alamos National Laboratory (Los Alamos) to gain skills in entrepreneurship and commercializing technology as part of their postdoctoral experience. This program will incorporate training and mentoring during the first 6-month period, culminating in a focused 6-month Fellowship aimed at creating a new business in Northern New Mexico.

Zero sound velocity in π, ρ mesons at different temperatures

International Nuclear Information System (INIS)

Dey, J.; Dey, M.; Tomio, L.; Araujo, C.F. de Jr.

1994-07-01

Sharp transitions are perhaps absent in QCD, so that one looks for physical quantities which may reflect the phase change. One such quantity is the sound velocity which was shown in lattice theory to become zero at the transition point for pure glue. We show that even in a simple bag model the sound velocity goes to zero at temperature T=T ν ≠ 0 and that the numerical value of this T ν depends on the nature of the meson. The average thermal energy of mesons go linearly with T near T ν , with much smaller slope for the pion. The T ν - s can be connected with the Boltzmann temperatures obtained from transverse momentum spectrum of these mesons in heavy ion collision at mid-rapidity. It would be interesting to check the presence of different T ν - s in present day finite T lattice theory. (author). 22 refs, 1 fig., 2 tabs

Dosimetry at the Los Alamos Critical Experiments Facility: Past, present, and future

International Nuclear Information System (INIS)

Malenfant, R.E.

1993-10-01

Although the primary reason for the existence of the Los Alamos Critical Experiments Facility is to provide basic data on the physics of systems of fissile material, the physical arrangements and ability to provide sources of radiation have led to applications for all types of radiation dosimetry. In the broad definition of radiation phenomena, the facility has provided sources to evaluate biological effects, radiation shielding and transport, and measurements of basic parameters such as the evaluation of delayed neutron parameters. Within the last 15 years, many of the radiation measurements have been directed to calibration and intercomparison of dosimetry related to nuclear criticality safety. Future plans include (1) the new applications of Godiva IV, a bare-metal pulse assembly, for dosimetry (including an evaluation of neutron and gamma-ray room return); (2) a proposal to relocate the Health Physics Research Reactor from the Oak Ridge National Laboratory to Los Alamos, which will provide the opportunity to continue the application of a primary benchmark source to radiation dosimetry; and (3) a proposal to employ SHEBA, a low-enrichment solution assembly, for accident dosimetry and evaluation

How to test entanglement for meson-antimeson systems

International Nuclear Information System (INIS)

Bertlmann, R.A.; Durstberger, K.; Hiesmayr, B.C.

2004-01-01

Also in particle physics basic questions of quantum mechanics can be raised and the peculiar behavior of entanglement can be investigated, which is the basic ingredient for the future technologies such as quantum information and quantum communication. A Bell inequality - analogous to the entangled photon system - can be derived, however, the inequality is not violated because of the 'unfortunate' constants in these systems. However, these entangled meson-antimeson systems offer other properties - not analogous to other known spin-1/2 systems - which open new insights, e.g. that the violation of the CP symmetry is related to entanglement. Another approach to study entanglement is via decoherence models. New data from the B-meson factory of the KEKB collider in Japan (BELLE detector) or the new data from the K-meson factory of the DAPHNE machine in Italy can be used to get upper bounds on decoherence and to test/exclude different decoherence models. Surprisingly, it turns out that the parameter extracted from the experiments is in simple connections to mathematical and theoretical concepts which in this way are directly confronted with experimental data. (author)

QCD bosonization and the meson effective action

International Nuclear Information System (INIS)

Praschifka, J.; Roberts, C.D.; Cahill, R.T.

1987-01-01

A bosonization of quantum chromodynamics (QCD) is employed to derive a meson effective action, thus providing a direct link between QCD and meson phenomenology. As an example of this approach expressions are obtained for the meson parameters associated with the analysis of ω→3π decay. The bosonization also directly motivates a divergence-free, global color-symmetry model for mesons, which is seen to be a generalization of various phenomenological models. Good estimates are obtained for the values of several of the meson parameters

The CDF silicon vertex trigger for B-mesons physics study

International Nuclear Information System (INIS)

Belforte, S.; Donati, S.; Ristori, L.; Spinella, F.; Budagov, Yu.; Chlachidze, G.; Glagolev, V.; Semenov, A.; Sisakyan, A.; Punzi, G.

2001-01-01

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 (B 0 → π + π - ) and B s mixing (B s 0 → D s - π + , B s 0 → D s - 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 (p t ), azimuthal angle (φ) and impact parameter (d) with 30 μm precision. The simulation studies show the background reduction by factor 1000 for B 0 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

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

Central Production of Two-Pseudoscalar Meson Systems at the COMPASS Experiment at CERN

CERN Document Server

Austregesilo, Alexander; Mallot, Gerhard

The question of the existence of glueballs is one of the unsolved problems in modern particle physics and can be regarded as a stringent test for quantum chromodynamics. Especially the supernumerous states in the light scalar meson spectrum are candidates for the observation of mixing effects between $q\\bar q$ mesons and pure gluonic bound states. On the other hand, the existence and the properties of many resonances in this sector are disputed. The COMPASS experiment was proposed to make significant contributions to this field. COMPASS is a fixed-target experiment at the CERN SPS which focused on light-quark hadron spectroscopy during the data taking periods in 2008 and 2009. A world-leading data set was collected with a $190\\,\\mathrm{GeV}/c$ hadron beam impinging on a liquid hydrogen target in order to study, inter alia, the central production of glueball candidates in the light meson sector. Especially the double-Pomeron exchange mechanism is well suited for the production of mesons without valenc...

ρ-meson self-energy and dielectron emissivity in an isospin-asymmetric pion medium

International Nuclear Information System (INIS)

Titov, A.I.; Gulamov, T.I.; Kaempfer, B.

1996-01-01

The ρ-meson self-energy in an isospin-asymmetric pion gas at finite temperature and charged-pion chemical potential is evaluated. We utilize a conventional effective π-ρ Lagrangian and the functional integral representation of the partition function in the second order in the ρππ coupling constant. We analyze the ρ-meson polarization operator and its dependence on the invariant mass M and spatial momentum parallel p parallel of the ρ meson. The pole positions and the values of the imaginary parts of the self-energy for different polarization states have different functional dependences on M and parallel p parallel. The corresponding dielectron rate (calculated from the imaginary part of the in-medium ρ-meson propagator) shows a distinctive asymmetry when the momentum t=p + -p - is perpendicular or parallel to p, where p ± are the e ± momenta of the electron pair. copyright 1996 The American Physical Society

Interplay of mesonic and baryonic degrees of freedom in quark matter

Energy Technology Data Exchange (ETDEWEB)

Khan, Naseemuddin

2015-11-03

In this work we study the influence of mesonic and baryonic fluctuations on the phase diagram of quark matter with two flavors. By examining the hadronization process and related techniques, we derive effective low-energy models, where the gluons are integrated out. To be able to compare our model calculations with lattice results at finite chemical potential, we investigate a QCD-like theory with two colors, where the sign-problem is absent. To this end we introduce a quark-meson-diquark model, where the bosonic diquarks play the role of colorless, baryonic degrees of freedom competing with the mesons. To access the phase diagram and determine the phases of chiral and diquark condensation, we employ a functional renormalization group approach allowing for a systematic non-perturbative truncation scheme. Interesting phenomena arise that are known from condensed matter physics, as the BEC-BSC crossover and a phase of condensation within domains. We explore the impact of running wave function renormalizations and Yukawa couplings for the quarks and the boson fields on top of the scale dependence of the effective potential. In the course of this we discuss the Silver Blaze property and its realization within a functional approach. In parallel, we formulate a quark-meson-diquark-baryon model for physical QCD as a low-energy effective theory for baryonic matter at high density, and discuss the relevance of the diquark and baryon degrees of freedom. In this sense, we compute a phase diagram for QCD from functional methods, including a color superconducting phase.

Separate T, CP, CPT Asymmetries in Neutral Meson Transitions

Science.gov (United States)

Bernabéu, José

2017-07-01

Symmetries, and Symmetry Breakings, in the Laws of Physics play a crucial role in Fundamental Science. Parity and Charge Conjugation Violations prompted the consideration of Chiral Fields in the construction of the Standard Model, whereas CP-Violation needed at least three families of Quarks leading to Flavour Physics. In this Lecture I will discuss the Conceptual Basis and the present experimental results for a Direct Evidence of Separate Reversal-in-Time T, CP and CPT Genuine Asymmetries in Decaying Particles like Neutral Meson Transitions, using Quantum Entanglement and the Decay as a Filtering Measurement. The eight transitions associated to the Flavour-CP eigenstate decay products of entangled neutral mesons have demonstrated with impressive significance a separate evidence of TRV and CPV in Bd-physics, whereas a CPTV asymmetry shows a 2-σ effect interpreted as an upper limit. Novel CPTV observables are discussed for K and Bd transitions. Their observation would lead to a change of paradigm beyond Quantum Field Theory, however there is nothing in Quantum Mechanics forbidding CPTV. A clean methodology to disentangle CPTV effects in the Hamiltonian dynamics and the ω-effect weakening Entanglement in a given experiment is discussed.

In-medium QCD sum rules for {omega} meson, nucleon and D meson

Energy Technology Data Exchange (ETDEWEB)

Thomas, Ronny

2008-07-01

The modifications of hadronic properties caused by an ambient nuclear medium are investigated within the scope of QCD sum rules. This is exemplified for the cases of the {omega} meson, the nucleon and the D meson. By virtue of the sum rules, integrated spectral densities of these hadrons are linked to properties of the QCD ground state, quantified in condensates. For the cases of the {omega} meson and the nucleon it is discussed how the sum rules allow a restriction of the parameter range of poorly known four-quark condensates by a comparison of experimental and theoretical knowledge. The catalog of independent four-quark condensates is covered and relations among these condensates are revealed. The behavior of four-quark condensates under the chiral symmetry group and the relation to order parameters of spontaneous chiral symmetry breaking are outlined. In this respect, also the QCD condensates appearing in differences of sum rules of chiral partners are investigated. Finally, the effects of an ambient nuclear medium on the D meson are discussed and relevant condensates are identified. (orig.)

In-medium pseudoscalar D/B mesons and charmonium decay width

Energy Technology Data Exchange (ETDEWEB)

Chhabra, Rahul; Kumar, Arvind [Dr. B.R. Ambedkar National Institute of Technology Jalandhar, Department of Physics, Jalandhar, Punjab (India)

2017-05-15

Using QCD sum rules and the chiral SU(3) model, we investigate the effect of temperature, density, strangeness fraction and isospin asymmetric parameter on the shift in masses and decay constants of the pseudoscalar D and B meson in the hadronic medium, which consist of nucleons and hyperons. The in-medium properties of D and B mesons within the QCD sum rule approach depend upon the quark and gluon condensates. In the chiral SU(3) model, quark and gluon condensates are introduced through the explicit symmetry breaking term and the trace anomaly property of the QCD, respectively and are written in terms of the scalar fields σ, ζ, δ and χ. Hence, through medium modification of σ, ζ, δ and χ fields, we obtain the medium-modified masses and decay constants of D and B mesons. As an application, using {sup 3}P{sub 0} model, we calculate the in-medium decay width of the higher charmonium states ψ(3686), ψ(3770) and χ(3556) to the D anti D pairs, considering the in-medium mass of D mesons. These results may be important to understand the possible outcomes of the high-energy physics experiments, e.g., CBM and PANDA at GSI, Germany. (orig.)

In-medium pseudoscalar D/B mesons and charmonium decay width

Science.gov (United States)

Chhabra, Rahul; Kumar, Arvind

2017-05-01

Using QCD sum rules and the chiral SU(3) model, we investigate the effect of temperature, density, strangeness fraction and isospin asymmetric parameter on the shift in masses and decay constants of the pseudoscalar D and B meson in the hadronic medium, which consist of nucleons and hyperons. The in-medium properties of D and B mesons within the QCD sum rule approach depend upon the quark and gluon condensates. In the chiral SU(3) model, quark and gluon condensates are introduced through the explicit symmetry breaking term and the trace anomaly property of the QCD, respectively and are written in terms of the scalar fields σ, ζ, δ and χ. Hence, through medium modification of σ, ζ, δ and χ fields, we obtain the medium-modified masses and decay constants of D and B mesons. As an application, using {}3P0 model, we calculate the in-medium decay width of the higher charmonium states ψ(3686), ψ(3770) and χ(3556) to the D\\bar{D} pairs, considering the in-medium mass of D mesons. These results may be important to understand the possible outcomes of the high-energy physics experiments, e.g., CBM and PANDA at GSI, Germany.

Proton Radiography at Los Alamos

Energy Technology Data Exchange (ETDEWEB)

Saunders, Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-02-28

The proton radiography (pRad) facility at Los Alamos National Lab uses high energy protons to acquire multiple frame flash radiographic sequences at megahertz speeds: that is, it can make movies of the inside of explosions as they happen. The facility is primarily used to study the damage to and failure of metals subjected to the shock forces of high explosives as well as to study the detonation of the explosives themselves. Applications include improving our understanding of the underlying physical processes that drive the performance of the nuclear weapons in the United States stockpile and developing novel armor technologies in collaboration with the Army Research Lab. The principle and techniques of pRad will be described, and examples of some recent results will be shown.

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}.

A neural network to identify neutral mesons

International Nuclear Information System (INIS)

Lefevre, F.; Lautridou, P.; Marques, M.; Matulewicz, T.; Ostendorf, R.; Schutz, Y.

1994-01-01

Both π 0 and η mesons decay long before they can reach a detector. They predominantly decay by emission of two photons, and are identified by constructing the invariant mass of the photons. Misidentified mesons result from ambiguity in associating photons. Our work tries to select which pair is the most likely to be a physical one rather than a chance one. We first designed a Hopfield neural net, but all the activities converged rapidly towards zero except the highest one. To improve the solution we slew down the computation in order to let the network explore several states and to impose activities to converge towards one for all selected pairs. This was achieved by adding links connecting each cell to itself. The network performance is all the more interesting that the solid angle covered by the detector is greater than 15%. (D.L.). 5 refs

Mesons and quarks in nuclei

International Nuclear Information System (INIS)

Oset, E.

1980-01-01

A short review of the topic of mesons in nuclei is exposed paying particular attention to the relationship between several mesonic processes. Special emphasis is put into the microscopic pictures that can ultimately relate all these processes with the elementary coupling of mesons to the nuclear hadronic components. The importance of the short range part of the nuclear interaction opens the doors to a more basic understanding in terms of the quark components of nucleons and isobars. (orig.)

Direct CP Violation in Charmless Hadronic B-Meson Decays at the PEP-II Asymmetric B-Meson Factory

Energy Technology Data Exchange (ETDEWEB)

Telnov, Alexandre Valerievich; /UC, Berkeley

2005-05-06

The study of the quark transition b {yields} s{bar s}s, which is a pure loop-level (''penguin'') process leading to several B-meson-decay final states, most notably {phi}K, is arguably the hottest topic in B-meson physics today. The reason is the sensitivity of the amplitudes and the CP-violating asymmetries in such processes to physics beyond the Standard Model. By performing these measurements, we improve our understanding of the phenomenon of combined-parity (CP) violation, which is believed to be responsible for the dominance of matter over antimatter in our Universe. Here, we present measurements of branching fractions and charge asymmetries in the decays B{sup +} {yields} {phi}K{sup +} and B{sup 0} {yields} {phi}K{sup 0} in a sample of approximately 89 million B{bar B} pairs collected by the BABAR detector at the PEP-II asymmetric-energy B-meson Factory at SLAC. We determine {Beta}(B{sup +} {yields} {phi}K{sup +}) = (10.0{sub -0.8}{sup +0.9} {+-} 0.5) x 10{sup -6} and {Beta}(B{sup 0} {yields} {phi}K{sup 0}) = (8.4{sub -1.3}{sup +1.5} {+-} 0.5) x 10{sup -6}, where the first error is statistical and the second is systematic. Additionally, we measure the CP-violating charge asymmetry {Alpha}{sub CP}(B{sup {+-}} {yields} {phi}K{sup {+-}}) = 0.04 {+-} 0.09 {+-} 0.01, with a 90% confidence-level interval of [-0.10, 0.18], and set an upper limit on the CKM- and color-suppressed decay B{sup +} {yields} {phi}{pi}{sup +}, {Beta}(B{sup +} {yields} {phi}{pi}{sup +}) < 0.41 x 10{sup -6} (at the 90% confidence level). Our results are consistent with the Standard Model, which predicts {Alpha}{sub CP}(B{sup {+-}} {yields} {phi}K{sup {+-}}) {approx}< 1% and {Beta}(B {yields} {phi}{tau}) << 10{sup -7}. Since many models of physics beyond the Standard Model introduce additional loop diagrams with new heavy particles and new CP-violating phases that would contribute to these decays, potentially making {Alpha}{sub CP} (B{sup {+-}} {yields} {phi

Towers of hybrid mesons

International Nuclear Information System (INIS)

Semay, Claude; Buisseret, Fabien; Silvestre-Brac, Bernard

2009-01-01

A hybrid meson is a quark-antiquark pair in which, contrary to ordinary mesons, the gluon field is in an excited state. In the framework of constituent models, the interaction potential is assumed to be the energy of an excited string. An approximate, but accurate, analytical solution of the Schroedinger equation with such a potential is presented. When applied to hybrid charmonia and bottomonia, towers of states are predicted in which the masses are a linear function of a harmonic oscillator band number for the quark-antiquark pair. Such a formula could be a reliable guide for the experimental detection of heavy hybrid mesons.

Charge parity exotic mesons

International Nuclear Information System (INIS)

Burden, C.J.

1998-01-01

Full text: Evidence for a meson with exotic quantum numbers J PC 1 -+ , the ρ(1405), has been observed at the AGS at Brookhaven and Crystal Barrel at CERN. This meson is exotic to the extent that its quantum numbers are not consistent with the generalised Pauli exclusion principle applied to the naive constituent quark model. In a fully relativistic field theoretic treatment, however, there is nothing in principle to preclude the existence of charge parity exotics. Using our earlier covariant Bethe-Salpeter model of light-quark mesons with no new parameter fitting we demonstrate the existence of a q - q-bar bound state with the quantum numbers of the ρ

Gamma-ray isotopic analysis development at Los Alamos

Energy Technology Data Exchange (ETDEWEB)

Thomas E. Sampson

1999-11-01

This report describes the development history and characteristics of software developed in the Safeguards Science and Technology group at Los Alamos for gamma-ray isotopic analysis. This software analyzes the gamma-ray spectrum from measurements performed on actinide samples (principally plutonium and uranium) of arbitrary size, geometry, and physical and chemical composition. The results are obtained without calibration using only fundamental tabulated nuclear constants. Characteristics of the current software versions are discussed in some detail and many examples of implemented measurement systems are shown.

Proceedings of High Energy Physics Workshop ''Scalar Mesons: An Interesting Puzzle for QCD'' held at SUNY Institute of Technology, May 16-18, 2003 Published by the American Institute of Physics AIP Conference Proceedings 688 Editor: Amir H. Fariborz

International Nuclear Information System (INIS)

Fariborz, Amir H.

2003-01-01

The proceedings of the workshop: ''Scalar Mesons: An Interesting Puzzle for QCD'' contains papers that were presented at the workshop by a number of experts from around the world. It includes three main categories of Theoretical, Computational and Experimental works. The topics that are presented in this proceedings are of interest to senior and junior investigators in high energy physics, nuclear physics and computational physics, and provide most recent ideas, techniques, and directions for future research in these fields

New physics effects in charm meson decays involving c → ul{sup +}l{sup -}(l{sub i}{sup -+}l{sub j}{sup ±}) transitions

Energy Technology Data Exchange (ETDEWEB)

Sahoo, Suchismita; Mohanta, Rukmani [University of Hyderabad, School of Physics, Hyderabad (India)

2017-05-15

We study the effect of the scalar leptoquark and Z{sup '} boson on the rare decays of the D mesons involving flavour changing transitions c → ul{sup +}l{sup -}(l{sub i}{sup -+}l{sub j}{sup ±}). We constrain the new physics parameter space using the branching ratio of the rare decay mode D{sup 0} → μ{sup +}μ{sup -} and the D{sup 0} - anti D{sup 0} oscillation data. We compute the branching ratios, forward-backward asymmetry parameters and flat terms in D{sup +(0)} → π{sup +(0)} μ{sup +}μ{sup -} processes using the constrained parameters. The branching ratios of the lepton flavour violating D meson decays, such as D{sup 0} → μe, τe and D{sup +(0)} → π{sup +(0)} μ{sup -}e{sup +} are also investigated. (orig.)

Meson-meson bound state in a 2+1 lattice QCD model with two flavors and strong coupling

International Nuclear Information System (INIS)

Faria da Veiga, Paulo A.; O'Carroll, Michael; Neto, Antonio Francisco

2005-01-01

We consider the existence of bound states of two mesons in an imaginary-time formulation of lattice QCD. We analyze an SU(3) theory with two flavors in 2+1 dimensions and two-dimensional spin matrices. For a small hopping parameter and a sufficiently large glueball mass, as a preliminary, we show the existence of isoscalar and isovector mesonlike particles that have isolated dispersion curves (upper gap up to near the two-particle threshold ∼-4lnκ). The corresponding meson masses are equal up to and including O(κ 3 ) and are asymptotically of order -2lnκ-κ 2 . Considering the zero total isospin sector, we show that there is a meson-meson bound state solution to the Bethe-Salpeter equation in a ladder approximation, below the two-meson threshold, and with binding energy of order bκ 2 ≅0.02359κ 2 . In the context of the strong coupling expansion in κ, we show that there are two sources of meson-meson attraction. One comes from a quark-antiquark exchange. This is not a meson exchange, as the spin indices are not those of the meson particle, and we refer to this as a quasimeson exchange. The other arises from gauge field correlations of four overlapping bonds, two positively oriented and two of opposite orientation. Although the exchange part gives rise to a space range-one attractive potential, the main mechanism for the formation of the bound state comes from the gauge contribution. In our lattice Bethe-Salpeter equation approach, this mechanism is manifested by an attractive distance-zero energy-dependent potential. We recall that no bound state appeared in the one-flavor case, where the repulsive effect of Pauli exclusion is stronger

Search for rare B meson decays into Ds+ mesons

International Nuclear Information System (INIS)

Albrecht, H.; Ehrlichmann, H.; Hamacher, T.; Hofmann, R.P.; Kirchhoff, T.; Nau, A.; Nowak, S.; Schroeder, H.; Schulz, H.D.; Walter, M.; Wurth, R.; Appuhn, R.D.; Hast, C.; Kolanoski, H.; Lange, A.; Lindner, A.; Mankel, R.; Schieber, M.; Siegmund, T.; Spaan, B.; Thurn, H.; Toepfer, D.; Walther, A.; Wegener, D.; Britton, D.I.; Charlesworth, C.E.K.; Edwards, K.W.; Hyatt, E.R.F.; Kapitza, H.; Krieger, P.; MacFarlane, D.B.; Patel, P.M.; Prentice, J.D.; Saull, P.R.B.; Tzamariudaki, K.; Van de Water, R.G.; Yoon, T.S.; Ressing, D.; Schmidtler, M.; Schneider, M.; Schubert, K.R.; Strahl, K.; Waldi, R.; Weseler, S.; Balagura, V.; Belyaev, I.; Chechelnitsky, S.; Danilov, M.; Droutskoy, A.; Gershtein, Yu.; Golutvin, A.; Gorelov, I.; Kostina, G.; Lubimov, V.; Pakhlov, P.; Ratnikov, F.; Semenov, S.; Shibaev, V.; Soloshenko, V.; Tichomirov, I.; Zaitsev, Yu.

1993-01-01

A search has been performed for rare B meson decays into D s + mesons arising from b→u transitions, W exchange modes, B + annihilation processes, and decays where the D s + is not produced via a W→c anti s quark pair coupling, using the ARGUS detector operating on the Y(4S) resonance at the e + e - storage ring DORIS II. Upper limits for individual decay modes are obtained. In addition, from a study of D s + l - correlations an upper limit of BR(B→D s + l - X)<1.2%(90% CL) is determined. (orig.)

From meson- and photon-nucleon scattering to vector mesons in nuclear matter

International Nuclear Information System (INIS)

Wolf, Gy.; Lutz, M.F.M.; Friman, B.

2003-01-01

A relativistic and unitary approach to pion- and photon-nucleon scattering taking into account the πN, ρN, ωN, ηN, πΔ, KΛ and KΣ channels is presented. The scheme dynamically generates the s- and d-wave baryon resonances N(1535), N(1650), N(1520) and N(1700) and as well as Δ(1620) and Δ(1700) in terms of quasi-local two-body interaction terms. A fair description of the experimental data relevant to the properties of slow vector mesons in nuclear matter is obtained. The resulting s-wave ρ- and ω-meson-nucleon scattering amplitudes which define the leading density modification of the ρ- and ω-meson spectral functions in nuclear matter are presented. (author)

Linac design study for an intense neutron-source driver

International Nuclear Information System (INIS)

Lynch, M.T.; Browman, A.; DeHaven, R.; Jameson, R.; Jason, A.; Neuschaefer, G.; Tallerico, P.; Regan, A.

1993-01-01

The 1-MW spallation-neutron source under design study at Los Alamos is driven by a linac-compressor-ring scheme that utilizes a large portion of the existing Los Alamos Meson Physics Facility (LAMPF) linac, as well as the facility infrastructure. The project is referred to as the National Center for Neutron Research (NCNR). A second phase of the proposal will upgrade the driver power to 5 MW. A description of the 1-MW scheme is given in this paper. In addition, the upgrade path to the substantial increase of beam power required for the 5 MW scenario is discussed

Materials performance experience at spallation neutron sources

Energy Technology Data Exchange (ETDEWEB)

Sommer, W.F. [Los Alamos National Laboratory, NM (United States)

1995-10-01

There is a growing, but not yet substantial, data base for materials performance at spallation neutron sources. Specially designed experiments using medium energy protons (650 MeV) have been conducted at the Proton Irradiation Experiment (PIREX) facility at the Swiss Nuclear Institute accelerator (SIN). Specially designed experiments using 760-800 MeV copper target have been completed at the Los Alamos Spallation Radiation Effects Facility (LASREF) at Los Alamos Meson Physics Facility (LAMPF). An extensive material testing program was initiated at LASREF in support of the German spallation neutron source (SNQ) project, before it terminated in 1985.

Los Alamos low-level waste performance assessment status

International Nuclear Information System (INIS)

Wenzel, W.J.; Purtymun, W.D.; Dewart, J.M.; Rodgers, J.E.

1986-06-01

This report reviews the documented Los Alamos studies done to assess the containment of buried hazardous wastes. Five sections logically present the environmental studies, operational source terms, transport pathways, environmental dosimetry, and computer model development and use. This review gives a general picture of the Los Alamos solid waste disposal and liquid effluent sites and is intended for technical readers with waste management and environmental science backgrounds but without a detailed familiarization with Los Alamos. The review begins with a wide perspective on environmental studies at Los Alamos. Hydrology, geology, and meteorology are described for the site and region. The ongoing Laboratory-wide environmental surveillance and waste management environmental studies are presented. The next section describes the waste disposal sites and summarizes the current source terms for these sites. Hazardous chemical wastes and liquid effluents are also addressed by describing the sites and canyons that are impacted. The review then focuses on the transport pathways addressed mainly in reports by Healy and Formerly Utilized Sites Remedial Action Program. Once the source terms and potential transport pathways are described, the dose assessment methods are addressed. Three major studies, the waste alternatives, Hansen and Rogers, and the Pantex Environmental Impact Statement, contributed to the current Los Alamos dose assessment methodology. Finally, the current Los Alamos groundwater, surface water, and environmental assessment models for these mesa top and canyon sites are described

Mesons above the deconfining transition

International Nuclear Information System (INIS)

De Forcrand, P.; Garcia Perez, M.; Hashimoto, T.

1999-01-01

We analyze temporal and spatial meson correlators in quenched lattice QCD at T > 0. Above T c we find different masses and (spatial) 'screening masses', signals of plasma formation, and indication of persisting 'mesonic' excitations. (author)

Scattering amplitudes to all orders in meson exchange

International Nuclear Information System (INIS)

Silbar, R.R.; Mattis, M.P.

1990-01-01

As the number of colors in QCD, N C , becomes large, it is possible to sum up all meson-exchange contributions, however arbitrarily complicated, to meson-baryon and baryon-baryon scattering. A semi-classical structure for the two-flavor theory emerges, in close correspondence to vector-meson-augmented Skyrme models. In this limit, baryons act as extended static sources for the classical meson fields. This leads to non-linear differential equations for the classical meson fields which can be solved numerically for static radial (hedgehog-like) solutions. The non-linear terms in the equations of motion for the quantized meson fields can then be simplified, to leading order in 1/N C , by replacing all factors of the meson field but one by the previously-found classical field. This results in linear, Schroedinger-like equations, which are easily solved. For the meson-baryon case the solution can be subsequently analyzed to obtain the phase shifts for the scattering and, from these, the baryon resonance spectrum of the model. As the warm-up, we have carried out this calculation for the simple case of σ mesons only, finding sensible results. 8 refs., 3 figs

Studies on inclusive meson resonance and particle production

International Nuclear Information System (INIS)

Saarikko, Heimo

1978-01-01

Production and decay of meson resonances are studied in medium energy meson-proton collisions. Strong evidence is found that hadronic collisions are dominated by resonance production. Especially the vector mesons have often large inclusive cross sections, typically of the order of few millibarns at the present energies. In all, a majority of pions and kaons appear to be decay products of resonances or other unstable particles. The detailed kinematics of the parent resonance's decays is found to play an important role in determining inclusive pion spectra. The squared transverse momentum distributions of hadrons heavier than the pion appear to have in common an exponential behaviour, with a universal slope for the esponential fall-off. The observed vector meson yields suggest that only a small fraction of the direct lepton production observed at large transverse momentum in nucleon-nucleon interactions is accounted for by the ''old'' vector mesons. An attempt has been made to separate out the central production and fragmentation components of the meson production. Both the central production and the fragmentation of the incoming meson are found to be important mechanisms in the non-strange meson production whereas the central production of strange meson resonances is rare at our energies. The ratios of the observed meson yields are found to be generally in good agreement with a simple quark-counting model. (author)

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.)

Single spin asymmetry for charm mesons

International Nuclear Information System (INIS)

Dominguez Zacarias, G.; Herrera, G.; Mercado, J.

2007-01-01

We study single spin asymmetries of D 0 and D - mesons in polarized proton-proton collisions. A two component model is used to describe charm meson production. The production of D mesons occurs by recombination of the constituents present in the initial state as well as by fragmentation of quarks in the final state. This model has proved to describe the production of charm. The recombination component involves a mechanism of spin alignment that ends up in a single spin asymmetry. Experimental measurements of single spin asymmetry for pions at RHIC are compared with the model. Predictions for the asymmetry in D mesons are presented. (orig.)

Meson Correlators in Finite Temperature Lattice QCD

CERN Document Server

De Forcrand, Philippe; Hashimoto, T; Hioki, S; Matsufuru, H; Miyamura, O; Nakamura, A; Takaishi, T; Umeda, T; Stamatescu, I O; CERN. Geneva; Forcrand, Ph. de

2001-01-01

We analyze temporal and spatial meson correlators in quenched lattice QCD at T>0. Below T_c we observe little change in the meson properties as compared with T=0. Above T_c we observe new features: chiral symmetry restoration and signals of plasma formation, but also indication of persisting mesonic (metastable) states and different temporal and spatial masses in the mesonic channels. This suggests a complex picture of QGP in the region 1 - 1.5 T_c.

Asymptotic energy scale factors for pseudoscalar meson scattering and charmed meson couplings

International Nuclear Information System (INIS)

Thews, R.L.

1977-01-01

Energy scale factors ν 0 for PP → PP scattering amplitudes are related via absence of exotic resonances of ratios of tensor to vector coupling strengths. These same ratios are extracted from FESR's for non-exotic reactions. The scale factors obtained are all of the order of 1.0 GeV 2 or less, indepedent of quantum numbers. This contradicts the expectations of dual amplitudes in which ν 0 =1/α', and trajectory slopes are smaller for charmed mesons. Decay widths for tensor mesons are predicted. An observed SU(3) violation for the ratio A 2 → KantiK/K** → Kπ is shown to be consistent with the FESR results. Charmed meson decays are predicted to be factors of 2 to 3 larger than those predicted by SU(4). (author)

Photoproduction of eta mesons from threshold to 1.2 GeV

International Nuclear Information System (INIS)

Rigney, A.; Breuer, M.; Hoffman-Rothe, P.; Anton, G.; Arends, J.; Berrier-Ronsin, G.; Beulertz, W.; Blanpied, G.; Bock, A.; Bruns, M.; Didelez, J.; Djaladi, C.; Edel, G.; Frascaria, R.; Maass, R.; Helbing, K.; Hey, J.; Noeldeke, G.; Hourani, E.; Mayers, M.; Preedom, B.; Ritchie, B.; Rosier, L.; Saghai, B.; Schumacher, M.; Smend, F.; Whisnant, S.

1995-01-01

We have measured total and differential cross sections for η-meson photo-production on 7 cm thick 1 H, 2 D, and 14 N liquid targets from threshold to 1.2 GeV, using the tagged Bremsstrahlung photon beam produced by the electrons extracted from the ELSA storage ring at Bonn. The photoreaction was identified by detecting the η 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. Some of our recent preliminary results, both theoretical and experimental, will be discussed. copyright 1995 American Institute of Physics

Heavy meson observables and Dyson-Schwinger equations

International Nuclear Information System (INIS)

Ivanov, M. A.

1998-01-01

Dyson-Schwinger equation (DSE) studies show that the b-quark mass-function is approximately constant, and that this is true to a lesser extent for the c-quark. This observation provides the basis for a study of the leptonic and semileptonic decays of heavy pseudoscalar mesons using a ''heavy-quark'' limit of the DSES, which, when exact, reduces the number of independent form factors. Semileptonic decays with light mesons in the final state are also accessible because the DSES provide a description of light-quark propagation characteristics and light-meson structure. A description of B-meson decays is straightforward, however, the study of decays involving the D-meson indicates that c-quark mass-corrections are quantitatively important

Parity violating nuclear force by meson mixing

International Nuclear Information System (INIS)

Iqbal, M.J.; Niskanen, J.A.

1990-01-01

We study a mechanism for parity violation in the two nucleon meson-exchange interaction by way of the mixing of mesons of opposite parities. This mixing arises from parity violating W ± and Z exchange between the q bar q pair in the meson. Numerically its effect turns out to be as important as vector meson exchange with a weak meson-nucleon vertex and may partly be used to model this vertex. The calculation is performed using both the standard Born approximation adding the amplitude phases by Watson's theorem and also using the exact correlated two-nucleon wave functions. The effect of correlations and form factors is found to be crucially important at intermediate energies

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.

About oscillations in the system of K0 mesons

International Nuclear Information System (INIS)

Beshtoev, Kh.M.

2011-01-01

This work considers K 0 -, K 0 bar - meson mixings and oscillations via K 1 0 , K 2 0 - meson states at strangeness violation by the weak interactions and K 1 0 -, K 2 0 - meson mixings and oscillations via K S -, K L - meson states at CP violation by the weak interactions without and with taking into account decay widths. We work in the framework of the masses mixing scheme. It is shown that K 1 0 -(K S -) meson states appear at big distances from the K 0 -mesons source after their decays (τ L ≥ τ S (τ 2 ≥τ 1 )) due to oscillations of residual K 2 0 (K L ) mesons and then again we see short-living K 1 0 (K S ) mesons. It is implied that K L ↔K S meson oscillations are absent. The case is also considered when at CP violation unitarity is violated, but orthogonality of K S , K L states remains. The general expressions for probabilities of meson oscillations (transitions) are given

Exclusive φ meson production in HERMES

International Nuclear Information System (INIS)

Golembiovskaya, Mayya

2014-03-01

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 1 , U 2 and U 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 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.

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.

Nucleons, mesons and quarks: the electron scattering approach

International Nuclear Information System (INIS)

Frois, B.

1985-05-01

A few examples of the research carried out by electron scattering in order to elucidate the relevant degrees of freedom for nuclear physics. Is considered first quasielastic scattering from 3 He which gives some insight into the properties of the nucleon in the nuclear medium. Then examples of meson exchange currents are presented. Finally, the present status of our understanding of shorter range effects is discussed

Semileptonic decays of B mesons into excited charm mesons: leading order and 1/mc contributions

International Nuclear Information System (INIS)

Mannel, T.

1994-01-01

We use the heavy quark effective theory to investigate the form factors that describe the semileptonic decays of a B meson into excited daughter mesons. For an excited daughter meson with charm, a single form factor is needed at leading order, while five form factors and two dimensionful constants are needed to order 1/m c in the heavy quark expansion. For non-charmed final states, a total of four form factors are needed at leading order. For the process B→D(*)Xlν, four form factors are also needed at leading order. (orig.)

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.

Discussion of the 3P0 model applied to the decay of mesons into two mesons

International Nuclear Information System (INIS)

Bonnaz, R.; Silvestre-Brac, B.

1999-01-01

The 3 P 0 model for the decay of a meson into two mesons is revisited. In particular, the formalism is extended in order to deal with an arbitrary form for the creation vertex and with the exact meson wave functions. A careful analysis of both effects is performed and discussed. The model is then applied to a large class of transitions known experimentally. Two types of quark-antiquark potentials have been tested and compared. (author)

Mass-producing B mesons

Energy Technology Data Exchange (ETDEWEB)

Aleksan, Roy; Ali, Ahmed

1993-06-15

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 Z resonance. Experiments at

Mass-producing B mesons

International Nuclear Information System (INIS)

Aleksan, Roy; Ali, Ahmed

1993-01-01

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

Production of excited charmed mesons at LEP

CERN Document Server

Abbaneo, D

2000-01-01

Studies od the production of orbitally excited charmed and charmed strange mesons in e+e- collisions, performed by the LEP collaborations are reviewed. Measurements of the production rates of orbitally excited charmed mesons in semileptonic b decays are presented. Searches for charmed meson radial excitations are also briefly discussed.

Rare decays of B-mesons

International Nuclear Information System (INIS)

Ali, A.

1992-01-01

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

Hard electroproduction of hybrid mesons

International Nuclear Information System (INIS)

Anikin, I.V.; LPT Universite Paris-Sud, Orsay; Szymanowski, L.; Teryaev, O.V.; ); Wallon, S.

2005-01-01

We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC = 1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e. as 1/Q 2 . This is due to the non-vanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in as and we explore the consequences of fixing the renormalization scale ambiguity through the BLM procedure. (author)

S-wave spectroscopy and Hyperne splitting of Bc meson

International Nuclear Information System (INIS)

Shah, Manan; Bhavsar, Tanvi; Vinodkumar, P.C.

2017-01-01

B c meson is the only heavy meson with two open flavours. This system is also interesting because they cannot annihilate into gluons. The mass spectra and hyperfine splitting of the B c meson are investigated in the Dirac framework with the help of linear + constant potential. The spin-spin interactions are also included in the calculation of the pseudoscalar and vector meson masses. Our computed result for the B c meson are in very good agreement with experimental results as well as other available theoretical result. Decay properties are also interesting because it is expected that decay of B c meson occur in to neutral meson. We hope our theoretical results are helpful for future experimental observations

Search for rare B meson decays into D+s mesons

International Nuclear Information System (INIS)

Albrecht, H.; Ehrlichmann, H.; Hamacher, T.

1993-04-01

A search has been performed for rare B meson decays into D s + mesons arising from b → u transitions, W exchange modes, B + annihilation processes, and decays where the D s + is not produced via a W → c anti s quark pair coupling, using the ARGUS detector operating on the Y(4S) resonance at the e + e - storage ring DORIS II. Upper limits for individual decay modes are obtained. In addition, from a study of D s + l - correlations an upper limit of BR(B → D s + l - X) < 1.2% (90% CL) is determined. (orig.)

Mesonic and Quark Degrees of Freedom in the Neutron Star Matter

International Nuclear Information System (INIS)

Kubis, S.; Kutschera, M.; Niemiec, J.; Stachniewicz, S.

1999-01-01

Full text: It is expected that mesonic and quark degrees of freedom may play an important role in the physics of dense matter in neutron stars. Any conclusions, however, as to the presence of e.g. meson condensates and/or quark matter inside neutron stars are subject to uncertainties which reflect incompatible model predictions at a purely nucleon level. In our project, as far as mesonic contributions to the equation of state of dense matter are concerned, we focus on the role of kaons and the isovector scalar meson a 0 (980). We find that a threshold density for the kaon condensate to form is very sensitive to a high density behaviour of the electron chemical potential, which is not well known due to uncertainties of nucleon-nucleon interactions. An important effect of the inclusion of the a 0 meson is a splitting of proton and neutron masses in the neutron star matter. A proper construction of the nucleon-quark phase transition in dense neutron star matter predicts that nucleons and quarks coexist over a finite range of pressure, with quarks (nucleons) filling gradually larger (smaller) fraction of space. We find, using a simple bag-model equation of state for the quark matter, that properties of such a mixed quark-nucleon phase are determined by the behaviour of nucleon matter isobars which is sensitive to the nuclear symmetry energy at high densities. We study also implications of the presence of a mixed phase for the structure of neutron stars. (author)

Analysis results from the Los Alamos 2D/3D program

International Nuclear Information System (INIS)

Boyack, B.E.; Cappiello, M.W.; Stumpf, H.; Shire, P.; Gilbert, J.; Hedstrom, J.

1986-01-01

Los Alamos National Laboratory is a participant in the 2D/3D program. Activities conducted at Los Alamos National Laboratory in support of 2D/3D program goals include analysis support of facility design, construction, and operation; provision of boundary and initial conditions for test facility operations based on analysis of pressurized water reactors; performance of pretest and posttest predictions and analyses; and use of experimental results to validate and assess the single- and multidimensional nonequilibrium features in the Transient Reactor Analysis Code (TRAC). During Fiscal Year 1986, Los Alamos conducted analytical assessment activities using data from the Cylindrical Core Test Facility and the Slab Core Test Facility. Los Alamos also continued to provide support analysis for the planning of Upper Plenum Test Facility experiments. Finally, Los Alamos either completed or is currently working on three areas of TRAC modeling improvement. In this paper, Los Alamos activities during Fiscal Year 1986 are summarized; several significant accomplishments are described in more detail to illustrate the work activities at Los Alamos

The role of top in heavy flavor physics

Energy Technology Data Exchange (ETDEWEB)

Hewett, J.L. [Stanford Linear Accelerator Center, Stanford, CA (United States)

1997-01-01

The implications of the massive top quark on heavy flavor transitions are explored. We review the generation of quark masses and mixings and the determination techniques, and present the status of the elements of the weak mixing matrix. Purely leptonic decays of heavy mesons are briefly summarized. We present a general introduction to flavor changing neutral currents and an extensive summary of radiative and other rare decay modes. The physics of neutral meson mixing is reviewed and applied to each meson system. We describe the phenomenology of CP violation and how it may be measured in meson decays. Standard Model predictions are given in each case and the effects of physics beyond the Standard Model are also discussed. Throughout, we contrast these transitions in the K and B meson systems to those in the D meson and top-quark sectors.

The role of top in heavy flavor physics

International Nuclear Information System (INIS)

Hewett, J.L.

1997-01-01

The implications of the massive top quark on heavy flavor transitions are explored. We review the generation of quark masses and mixings and the determination techniques, and present the status of the elements of the weak mixing matrix. Purely leptonic decays of heavy mesons are briefly summarized. We present a general introduction to flavor changing neutral currents and an extensive summary of radiative and other rare decay modes. The physics of neutral meson mixing is reviewed and applied to each meson system. We describe the phenomenology of CP violation and how it may be measured in meson decays. Standard Model predictions are given in each case and the effects of physics beyond the Standard Model are also discussed. Throughout, we contrast these transitions in the K and B meson systems to those in the D meson and top-quark sectors

Antiproton-proton annihilation into light neutral meson pairs within an effective meson theory

Science.gov (United States)

Wang, Ying; Bystritskiy, Yury M.; Ahmadov, Azad I.; Tomasi-Gustafsson, Egle

2017-08-01

Antiproton-proton annihilation into light neutral mesons in the few GeV energy domain is investigated in view of a global description of the existing data and predictions for future work at the Antiproton Annihilation at Darmstadt (PANDA) experiment at the Facility for Antiproton and Ion Research (FAIR). An effective meson model earlier developed, with mesonic and baryonic degrees of freedom in s , t , and u channels, is applied here to π0π0 production. Form factors with logarithmic s and t (u ) dependencies are applied. A fair agreement with the existing angular distributions is obtained. Applying SU(3) symmetry, it is straightforward to recover the angular distributions for π0η and η η production in the same energy range. A good agreement is generally obtained with all existing data.

Publications of Los Alamos Research, 1983

International Nuclear Information System (INIS)

Sheridan, C.J.; McClary, W.J.; Rich, J.A.; Rodriguez, L.L.

1984-10-01

This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1983. Papers published in 1982 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers publishd in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them

Publications of Los Alamos Research 1982

International Nuclear Information System (INIS)

McClary, W.J.; Rodriguez, L.L.; Sheridan, C.J.

1983-10-01

This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1982. Papers published in 1982 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassfiication of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them

Publications of Los Alamos Research, 1983

Energy Technology Data Exchange (ETDEWEB)

Sheridan, C.J.; McClary, W.J.; Rich, J.A.; Rodriguez, L.L. (comps.)

1984-10-01

This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1983. Papers published in 1982 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers publishd in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

Publications of Los Alamos research 1980

Energy Technology Data Exchange (ETDEWEB)

Salazar, C.A.; Willis, J.K. (comps.)

1981-09-01

This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1980. Papers published in 1980 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted-even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was pubished more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-laboratory reports, journal articles, books, chapters of books, conference papers published either separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

External meeting - Geneva University: Semileptonic and Radiative B-meson decays

CERN Multimedia

2007-01-01

GENEVA UNIVERSITY ECOLE DE PHYSIQUE Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet 1211 GENEVE 4 - Tél : 022 379 62 73 - Fax: 022 379 69 92 Wednesday 4 April 2007 PARTICLE PHYSICS SEMINAR at 17:00 - Stückelberg Auditorium Semileptonic and Radiative B-meson decays by Dr Antonio Limosani / K2K, Japon The success of the B Factories at KEK and SLAC has furthered our knowledge of CP violation, a necessary ingredient for the creation of a matter-dominanted universe. Ever increasing data samples has ushered in a new era of precision CP measurements, in which the unitarity of the Cabibbo-Kobayashi-Maskawa matrix is examined for signs of New Physics. One of the crucial pieces of information, surprisingly, comes not from CP violation but from studies of semileptonic decays of the B mesons. I will discuss how various measurements of semileptonic and radiative B decays combine together to provide a precision measurement of the CKM matrix element |Vcb| and to determine the value of s...

Results of a neutrino oscillation experiment performed at a meson factory beam-stop

International Nuclear Information System (INIS)

Mitchell, J.W.

1989-04-01

This document describes a neutrino oscillation experiment performed at the Los Alamos Meson Physics Facility. The oscillation mode searched for is /bar /nu///sub μ/ → /bar /nu///sub e/. The first chapter is a review of the known properties of the neutrino and a description of the phenomenon of neutrino oscillation. Previous experimental limits on this unobserved phenomenon are also given. The second chapter describes the experimental apparatus used by the E645 experiment to detect neutrinos produced in the LAMPF beam stop. The salient features of the detector are its large mass (20 tons of CH 2 ), its fine segmentation (to allow good particle tracking), good energy resolution, its recording of the history both before and after tracks appear in the detector, an active cosmic-ray anticoincidence shield, and 2000 gm/cm 2 of passive cosmic-ray shielding. It is located 26.8 m from the neutrino source, which has a mean neutrino energy of 40 MeV. The third chapter details the reduction of the 1.3 million event data sample to a 49 event sample of neutrino candidates. Principle backgrounds are Michel electrons from stopping cosmic-ray muons and protons from np elastic scattering by cosmic-ray neutrons. The fourth chapter explains how background levels from neutrino-nuclear scattering are predicted. The result of a maximum-likelihood analysis reveals no evidence for oscillation. 90% confidence levels are set at δm 2 = .10 eV 2 for large mixing and sin 2 (2θ) = .014 for large δm 2 . 82 refs., 18 figs., 55 tabs

Meson Spectroscopy at CLAS and CLAS12: the present and the future

International Nuclear Information System (INIS)

De Vita, R.

2011-01-01

Mesons are the simplest quark bound system, being made by a quark and an anti-quark pair. Studying their structure and properties is a fundamental step to reach a deep understanding of QCD. For this purpose both the precise determination of the meson spectrum for conventional states and the search for states beyond the simple qq-bar configurations, as hybrids (qqg) or glueballs, are needed. Finding evidence for these unconventional states would help in understanding some of the open issues in hadronic physics, as how the quarks are confined within hadrons and what is the role of gluons. These topics are presently studied with the CLAS detector at Jefferson Lab and will be studied with the novel CLAS12 experiment after the 12 GeV upgrade of the facility. In my talk I will present the physics program that is presently in progress and the future perspectives.

LAMPF: a nuclear research facility

International Nuclear Information System (INIS)

Livingston, M.S.

1977-09-01

A description is given of the recently completed Los Alamos Meson Physics Facility (LAMPF) which is now taking its place as one of the major installations in this country for the support of research in nuclear science and its applications. Descriptions are given of the organization of the Laboratory, the Users Group, experimental facilities for research and for applications, and procedures for carrying on research studies

Space Science at Los Alamos National Laboratory

Science.gov (United States)

Smith, Karl

2017-09-01

The Space Science and Applications group (ISR-1) in the Intelligence and Space Research (ISR) division at the Los Alamos National Laboratory lead a number of space science missions for civilian and defense-related programs. In support of these missions the group develops sensors capable of detecting nuclear emissions and measuring radiations in space including γ-ray, X-ray, charged-particle, and neutron detection. The group is involved in a number of stages of the lifetime of these sensors including mission concept and design, simulation and modeling, calibration, and data analysis. These missions support monitoring of the atmosphere and near-Earth space environment for nuclear detonations as well as monitoring of the local space environment including space-weather type events. Expertise in this area has been established over a long history of involvement with cutting-edge projects continuing back to the first space based monitoring mission Project Vela. The group's interests cut across a large range of topics including non-proliferation, space situational awareness, nuclear physics, material science, space physics, astrophysics, and planetary physics.

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.

PQCD analysis of inclusive semileptonic decays of B mesons

International Nuclear Information System (INIS)

Li, H.; Yu, H.

1996-01-01

We develop the perturbative QCD formalism for inclusive semileptonic B meson decays, which includes Sudakov suppression from the resummation of large radiative corrections near the high end of charged lepton energy. Transverse degrees of freedom of partons are introduced to facilitate the factorization of B meson decays. Ambiguities appearing in the quark-level analysis are then avoided. A universal distribution function, arising from the nonperturbative Fermi motion of the b quark, is constructed according to the heavy quark effective field theory based operator product expansion, through which the mean and the width of the distribution function are related to hadronic matrix elements of local operators. Charged lepton spectra of the B→X ul ν decay are presented. We find 50% suppression near the end point of the spectrum. The overall suppression on the total decay rate is 8% for the free quark model, and is less than 7% for the use of smooth distribution functions. With our predictions, it is then possible to extract the Cabibbo-Kobayashi-Maskawa matrix element parallel V ub parallel from experimental data. We also discuss possible implications of our analysis when confronted with the rather small observed semileptonic branching ratio in B meson decays. copyright 1996 The American Physical Society

Recent advances in excimer laser technology at Los Alamos

International Nuclear Information System (INIS)

Bigio, I.J.; Czuchlewski, S.; McCown, A.W.; Taylor, A.J.

1991-01-01

This paper reports that current research in excimer laser technology at Los Alamos progresses in two major areas: In the Bright Source program, the development of ultra-high brightness (sub-piosecond) laser systems, based on discharge -pumped excimer laser amplifiers, continues Recently the authors have completed rigorous measurements of the saturation parameter for ultra-short pulses. In the laser fusion program, implementation of the large KrF laser fusion amplifiers have been accompanied by numerous studies of the laser physics and kinetics of large e-beam pumped devices

Needs assessment for fire department services and resources for the Los Alamos National Laboratory, Los Alamos, New Mexico. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-11-15

This report has been developed in response to a request from the Los Alamos National Laboratory (LANL) to evaluate the need for fire department services so as to enable the Laboratory to plan effective fire protection and thereby: meet LANL`s regulatory and contractual obligations; interface with the Department of Energy (DOE) and other agencies on matters relating to fire and emergency services; and ensure appropriate protection of the community and environment. This study is an outgrowth of the 1993 Fire Department Needs Assessment (prepared for DOE) but is developed from the LANL perspective. Input has been received from cognizant and responsible representatives at LANL, DOE, Los Alamos County (LAC) and the Los Alamos Fire Department (LAFD).

Status of Monte Carlo at Los Alamos

International Nuclear Information System (INIS)

Thompson, W.L.; Cashwell, E.D.

1980-01-01

At Los Alamos the early work of Fermi, von Neumann, and Ulam has been developed and supplemented by many followers, notably Cashwell and Everett, and the main product today is the continuous-energy, general-purpose, generalized-geometry, time-dependent, coupled neutron-photon transport code called MCNP. The Los Alamos Monte Carlo research and development effort is concentrated in Group X-6. MCNP treats an arbitrary three-dimensional configuration of arbitrary materials in geometric cells bounded by first- and second-degree surfaces and some fourth-degree surfaces (elliptical tori). Monte Carlo has evolved into perhaps the main method for radiation transport calculations at Los Alamos. MCNP is used in every technical division at the Laboratory by over 130 users about 600 times a month accounting for nearly 200 hours of CDC-7600 time

Design features of a seven-cell high-gradient superconducting cavity

International Nuclear Information System (INIS)

Liska, D.J.; Ledford, J.; Black, S.; Spalek, G.; DiMarco, J.N.

1992-01-01

A cavity development program is in place at Los Alamos National Laboratory to evaluate structures that could be used to accelerate pions. The work is being guided by the conceptual design of PILAC, a high-gradient superconducting linac for raising the energy of rapidly decaying intense pion beams generated by Los Alamos Meson Physics Facility (LAMPF) to 1 GeV. The specification requires a cavity gradient of 12.5 MV/m at 805 MHz. The design of a seven-cell prototype cavity to achieve these high gradients has been completed by the Accelerator Technology division. The cavity is presently under procurement for high power testing a 2.0 K in 1993

White source gamma-ray production spectral measurement facilities in the USA

International Nuclear Information System (INIS)

Larson, D.C.; Dickens, J.K.; Nelson, R.O.; Wender, S.A.

1991-01-01

The two primary neutron sources for measuring gamma-ray production (GRP) cross sections for basic and applied work in the USA are the Oak Ridge Electron Linear Accelerator (ORELA) located at the Oak Ridge National Laboratory (ORNL) and the Weapons Neutron Research (WNR) facility located at the Los Alamos National Laboratory (LANL). ORELA is based on a 180-MeV electron linear accelerator, while the WNR facility uses the Los Alamos Meson Physics Facility 800 MeV proton beam to produce neutrons. The facilities collectively cover the neutron-energy range from thermal to over 700 MeV. The paper describes the present capabilities for GRP measurements at each facility. 18 refs

The phi-meson and Chiral-mass-meson production in heavy-ion collisions as potential probes of quark-gluon-plasma and Chiral symmetry transitions

Science.gov (United States)

Takahashi, Y.; Eby, P. B.

1985-01-01

Possibilities of observing abundances of phi mesons and narrow hadronic pairs, as results of QGP and Chiral transitions, are considered for nucleus-nucleus interactions. Kinematical requirements in forming close pairs are satisfied in K+K decays of S(975) and delta (980) mesons with small phi, and phi (91020) mesons with large PT, and in pi-pi decays of familiar resonance mesons only in a partially restored chiral symmetry. Gluon-gluon dominance in QGP can enhance phi meson production. High hadronization rates of primordial resonance mesons which form narrow hadronic pairs are not implausible. Past cosmic ray evidences of anomalous phi production and narrow pair abundances are considered.

Photoproduction of vector mesons off nucleons near threshold

International Nuclear Information System (INIS)

Friman, B.

1995-01-01

A simple meson-exchange model is proposed for the photoproduction of ρ- and ω-mesons off protons near threshold. This model provides a good description of the available data and implies a large ρ-nucleon interaction in the scalar channel (σ-exchange). This phenomenological interaction is applied to estimate the leading contribution to the self-energy of ρ-mesons in matter. The implications of our calculation for experimental studies of the ρ-meson mass in nuclei are discussed. (author)

Analysis results from the Los Alamos 2D/3D program

International Nuclear Information System (INIS)

Boyack, B.E.; Cappiello, M.W.; Harmony, S.C.; Shire, P.R.; Siebe, D.A.

1987-01-01

Los Alamos National Laboratory is a participant in the 2D/3D program. Activities conducted at Los Alamos National Laboratory in support of 2D/3D program goals include analysis support of facility design, construction, and operation; provision of boundary and initial conditions for test-facility operations based on analysis of pressurized water reactors; performance of pretest and posttest predictions and analyses; and use of experimental results to validate and assess the single- and multi-dimensional, nonequilibrium features in the Transient Reactor Analysis Code (TRAC). During fiscal year 1987, Los Alamos conducted analytical assessment activities using data from the Slab Core Test Facility, The Cylindrical Core Test Facility, and the Upper Plenum Test Facility. Finally, Los Alamos continued work to provide TRAC improvements. In this paper, Los Alamos activities during fiscal year 1987 will be summarized; several significant accomplishments will be described in more detail to illustrate the work activities at Los Alamos

Temperature, chemical potential and the ρ meson

International Nuclear Information System (INIS)

Roberts, C. D.; Schmidt, S. M.

2000-01-01

Models of QCD must confront nonperturbative phenomena such as confinement, dynamical chiral symmetry breaking (DCSB) and the formation of bound states. In addition, a unified approach should describe the deconfinement and chiral symmetry restoring phase transition exhibited by strongly-interacting matter under extreme conditions of temperature and density. Nonperturbative Dyson-Schwinger equation (DSE) models provide insight into a wide range of zero temperature hadronic phenomena; e.g., non-hadronic electroweak interactions of light- and heavy-mesons, and diverse meson-meson and meson-nucleon form factors. This is the foundation for their application at nonzero-(T, μ). Herein the authors describe the calculation of the reconfinement and chiral symmetry restoring phase boundary, and the medium dependence of ρ-meson properties. They also introduce an extension to describe the time-evolution in the plasma of the quark's scalar and vector self energies based on a Vlasov equation

Letter of intent for a study of CP violation in B meson decays

International Nuclear Information System (INIS)

1994-04-01

A major unresolved issue in the understanding of the Universe is how the current Universe evolved from the matter-antimatter symmetric Big Bang. CP-violating effects have played a key role in the development of the Universe. Since the Kobayashi-Maskawa hypothesis of six quarks has been substantiated, the K-M model for CP violation is now considered to be an essential part of the Standard Model. Observations indicated that it would be feasible to carry out the decisive tests of the K-M model by studying B meson decay. The observation of CP-violating asymmetry in B meson decay would be the first successful demonstration of a CP-violating effect outside K 0 meson system, and would be the dramatic confirmation of the K-M model. In light of the strong competition in this research, the upgrade of the TRISTAN facility and the construction of a detector must be ready as early as possible. In this letter of intent for the experiment at National Laboratory for High Energy Physics B Factory, the goals of this experiment, detector requirements and optimization, accelerator-detector interface, the reference design, physics simulation, and cost, schedule and organization are described. (K.I.) 140 refs

Spin O decay angular distribution for interfering mesons in electroproduction

Energy Technology Data Exchange (ETDEWEB)

Funsten, H.; Gilfoyle, G.

1994-04-01

Self analyzing meson electroproduction experiments are currently being planned for the CEBAF CLAS detector. These experiments deduce the spin polarization of outgoing unstable spin s (?)0 mesons from their decay angular distribution, W({theta},{psi}). The large angular acceptance of the CLAS detector permits kinematic tracking of a sufficient number of these events to accurately determine electroproduction amplitudes from the deduced polarization. Maximum polarization information is obtained from W({theta},{psi}) for decay into spin 0 daughters. The helicity of the decaying meson is transferred to the daughter`s relative orbital angular momentum m-projection; none is {open_quotes}absorbed{close_quotes} into daughter helicities. The decaying meson`s helicity maximally appears in W({theta},{psi}). W({theta},{psi}) for spin 0 daughters has been derived for (1) vector meson electroproduction and (2) general interfering mesons produced by incident pions. This paper derives W({theta},{psi}) for electroproduction of two interfering mesons that decay into spin 0 daughters. An application is made to the case of interfering scalar and vector mesons. The derivation is an extension of work by Schil using the general decay formalism of Martin. The expressions can be easily extended to the case of N interfering mesons since interference occurs pairwise in the observable W ({theta},{psi}), a quadratic function of the meson amplitudes. The derivation uses the virtual photon density matrix of Schil which is transformed by a meson electroproduction transition operator, T. The resulting density matrix for the interfering mesons is then converted into a corresponding statistical tensor and contracted into the efficiency tensor for spin 0 daughters.

The light scalar mesons as tetraquarks

Directory of Open Access Journals (Sweden)

Gernot Eichmann

2016-02-01

Full Text Available We present a numerical solution of the four-quark Bethe–Salpeter equation for ground-state scalar tetraquarks with JPC=0++. We find that the four-body equation dynamically generates pseudoscalar-meson poles in the Bethe–Salpeter amplitude. The resulting tetraquarks are genuine four-quark states that are dominated by pseudoscalar meson–meson correlations. Diquark–antidiquark contributions are subleading because of their larger mass scale. In the light quark sector, the sensitivity of the tetraquark wave function to the pion poles leads to an isoscalar tetraquark mass Mσ∼350 MeV which is comparable to that of the σ/f0(500. The masses of its multiplet partners κ and a0/f0 follow a similar pattern. This provides support for a tetraquark interpretation of the light scalar meson nonet in terms of ‘meson molecules’.

[Medium energy meson research

International Nuclear Information System (INIS)

Crowe, K.M.

1992-01-01

The activities of this group are primarily concerned with experiments using the Crystal Barrel Detector. This detector is installed and operating at the Low Energy Antiproton Ring (LEAR) at CERN. QCD, the modem theory of the strong interaction, is reasonably well understood at high energies, but unfortunately, low-energy QCD is still not well understood, and is far from being adequately tested. The Crystal Barrel experiments are designed to provide some of the tests. The basic line of research involves meson spectroscopy, analyses bearing on the quark and/or gluon content of nuclear states, and the exploration of mechanisms and rules which govern p bar p annihilation dynamics. The Crystal Barrel Detector detects and identifies charged and neutral particles with a geometric acceptance close to 100%. The principal component of the detector is an array of 1,380 CsI(TI) crystals. These crystals surround a Jet Drift Chamber (JDC), located in a 1.5 Tesla magnetic field, which measures the momentum and dE/dx of charged particles. One of the very interesting physics goals of the detector is a search for exotic mesonic states -- glueballs and hybrids. Annihilation at rest will be studied with both liquid and gaseous hydrogen targets. The gaseous target offers the possibility of triggering on atomic L-shell X rays so that specific initial angular momentum states can be studied.These topics as well as other related topics are discussed in this report

Commercialization of Los Alamos National Laboratory technologies via small businesses. Final report

Energy Technology Data Exchange (ETDEWEB)

Brice, R.; Carton, D.; Rhyne, T. [and others

1997-06-01

Appendices are presented from a study performed on a concept model system for the commercialization of Los Alamos National Laboratory technologies via small businesses. Topics include a summary of information from the joint MCC/Los Alamos technology conference; a comparison of New Mexico infrastructure to other areas; a typical licensing agreement; technology screening guides; summaries of specific DOE/UC/Los Alamos documents; a bibliography; the Oak Ridge National Laboratory TCRD; The Ames Center for Advanced Technology Development; Los Alamos licensing procedures; presentation of slides from monthly MCC/Los Alamos review meetings; generalized entrepreneurship model; and a discussion on receiving equity for technology.

Environmental analysis of Lower Pueblo/Lower Los Alamos Canyon, Los Alamos, New Mexico

International Nuclear Information System (INIS)

Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Becker, N.M.; Rodgers, J.C.; Hansen, W.R.

1994-12-01

The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, Pueblo Canyon, and Los Alamos Canyon found residual contamination at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons all the way to the Rio Grande. The largest reservoir of residual radioactivity is in lower Pueblo Canyon, which is on DOE property. However, residual radioactivity does not exceed proposed cleanup criteria in either lower Pueblo or lower Los Alamos Canyons. The three alternatives proposed are (1) to take no action, (2) to construct a sediment trap in lower Pueblo Canyon to prevent further transport of residual radioactivity onto San Ildefonso Indian Pueblo land, and (3) to clean the residual radioactivity from the canyon system. Alternative 2, to cleanup the canyon system, is rejected as a viable alternative. Thousands of truckloads of sediment would have to be removed and disposed of, and this effort is unwarranted by the low levels of contamination present. Residual radioactivity levels, under either present conditions or projected future conditions, will not result in significant radiation doses to persons exposed. Modeling efforts show that future transport activity will not result in any residual radioactivity concentrations higher than those already existing. Thus, although construction of a sediment trap in lower Pueblo Canyon is a viable alternative, this effort also is unwarranted, and the no-action alternative is the preferred alternative

Environmental analysis of Lower Pueblo/Lower Los Alamos Canyon, Los Alamos, New Mexico

Energy Technology Data Exchange (ETDEWEB)

Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Becker, N.M.; Rodgers, J.C.; Hansen, W.R.

1994-12-01

The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, Pueblo Canyon, and Los Alamos Canyon found residual contamination at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons all the way to the Rio Grande. The largest reservoir of residual radioactivity is in lower Pueblo Canyon, which is on DOE property. However, residual radioactivity does not exceed proposed cleanup criteria in either lower Pueblo or lower Los Alamos Canyons. The three alternatives proposed are (1) to take no action, (2) to construct a sediment trap in lower Pueblo Canyon to prevent further transport of residual radioactivity onto San Ildefonso Indian Pueblo land, and (3) to clean the residual radioactivity from the canyon system. Alternative 2, to cleanup the canyon system, is rejected as a viable alternative. Thousands of truckloads of sediment would have to be removed and disposed of, and this effort is unwarranted by the low levels of contamination present. Residual radioactivity levels, under either present conditions or projected future conditions, will not result in significant radiation doses to persons exposed. Modeling efforts show that future transport activity will not result in any residual radioactivity concentrations higher than those already existing. Thus, although construction of a sediment trap in lower Pueblo Canyon is a viable alternative, this effort also is unwarranted, and the no-action alternative is the preferred alternative.

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

Meson spectroscopy, quark mixing and quantum chromodynamics

International Nuclear Information System (INIS)

Filippov, A.T.

1979-01-01

A semiphenomenological theory of mass spectrum for mesons, consisting of a quark-antiquark pair, is presented. Relativistic kinematical effects of the quark mass differences, the SU(3)-symmetry breaking in slopes of the Regge trajectories and in radially excited states are taken into account. The OZI-rule breaking is taken into account by means of the mixing matrix for the quark wave functions, whose form is suggested by the quantum chromodynamics. A simple extrapolation of expression, given by the quantum chromodynamics from the ''asymptotic freedom'' region to the ''infrared slavery'' region is proposed to describe the dependence of the mixing parameters on the meson masses. To calculate masses and mixing angles for pseudoscalar mesons a condition is proposed that the pion mass is minimal. In this situation the eta-meson mass is near the maximal value. The predictions of the theory for masses and mixing angles of the mesons are in good agreement with the experiment

New Generation of Los Alamos Opacity Tables

Science.gov (United States)

Colgan, James; Kilcrease, D. P.; Magee, N. H.; Sherrill, M. E.; Abdallah, J.; Hakel, P.; Fontes, C. J.; Guzik, J. A.; Mussack, K. A.

2016-05-01

We present a new generation of Los Alamos OPLIB opacity tables that have been computed using the ATOMIC code. Our tables have been calculated for all 30 elements from hydrogen through zinc and are publicly available through our website. In this poster we discuss the details of the calculations that underpin the new opacity tables. We also show several recent applications of the use of our opacity tables to solar modeling and other astrophysical applications. In particular, we demonstrate that use of the new opacities improves the agreement between solar models and helioseismology, but does not fully resolve the long-standing `solar abundance' problem. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396.

Strange mesonic transition form factor in the chiral constituent quark model

International Nuclear Information System (INIS)

Ito, H.; Ramsey-Musolf, M.J.

1998-01-01

The form factor g ρπ (S) (Q 2 ) of the strange vector current transition matrix element left-angle ρ|bar sγ μ s|π right-angle is calculated within the chiral quark model. A strange vector current of the constituent U and D quarks is induced by kaon radiative corrections and this mechanism yields the nonvanishing values of g ρπ (S) (0). The numerical result at the photon point is consistent with the one given by the φ-meson dominance model, but the falloff in the Q 2 dependence is faster than the monopole form factor. Mesonic radiative corrections are also examined for the electromagnetic ρ-to-π and K * -to-K transition amplitudes. copyright 1998 The American Physical Society

Chiral Extrapolations of the $\\boldsymbol{ρ(770)}$ Meson in $\\mathbf{N_f=2+1}$ Lattice QCD Simulations

Energy Technology Data Exchange (ETDEWEB)

Molina, Raquel [Univ. of Sao Paulo (Brazil); Hu, Bitao [George Washington Univ., Washington, DC (United States); Doering, Michael [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); George Washington Univ., Washington, DC (United States); Mai, Maxim [George Washington Univ., Washington, DC (United States); Alexandru, Andrei [George Washington Univ., Washington, DC (United States)

2018-04-01

Several lattice QCD simulations of meson-meson scattering in p-wave and Isospin = 1 in Nf = 2 + 1 flavours have been carried out recently. Unitarized Chiral Perturbation Theory is used to perform extrapolations to the physical point. In contrast to previous findings on the analyses of Nf = 2 lattice data, where most of the data seems to be in agreement, some discrepancies are detected in the Nf = 2 + 1 lattice data analyses, which could be due to different masses of the strange quark, meson decay constants, initial constraints in the simulation, or other lattice artifacts. In addition, the low-energy constants are compared to the ones from a recent analysis of Nf = 2 lattice data.

Materials accounting at Los Alamos National Laboratory

International Nuclear Information System (INIS)

Erkkila, B.H.; Roberts, N.J.

1989-01-01

This presentation gives an overview of the accounting system used at the Los Alamos National Laboratory by the Los Alamos Nuclear Material Accounting and Safeguards System (MASS). This system processes accounting data in real time for bulk materials, discrete items, and materials undergoing dynamic processing. The following topics are covered in this chapter: definitions; nuclear material storage; nuclear material storage; computer system; measurement control program; inventory differences; and current programs and future plans

Further evidence for magnetic charge from meson spectroscopy

International Nuclear Information System (INIS)

Akers, D.

1987-01-01

Recently evidence was presented for the existence of magnetic charge from Zeeman splitting in meson states. The model by Akers predicted the existence of a new eta meson at 1814 MeV with I/sup G/ (J/sup PC/) = O + (O -+ ). Experimental evidence for this new meson is cited and discussed

The Meson Spectroscopy Program at the Jefferson Laboratory

Energy Technology Data Exchange (ETDEWEB)

Filippi, Alessandro [Istituto Nazionale di Fisica Nucleare (INFN), Torino (Italy). et al.

2015-06-01

The experimental techniques that will be applied by the next generation meson spectroscopy experiments at JLab are described. For the first time, these experiments will be able to exploit the features of a photon beam of unprecedented intensity and momentum resolution, that will allow to perform precision studies of meson states with masses below 3 GeV/c². Photon induced reactions will enhance the production of spin-1 mesons, that are of particular interest according to the most recent Lattice QCD calculations of the lightest exotic hybrid meson.

Photoproduction of vector mesons off nucleons near threshold

International Nuclear Information System (INIS)

Friman, B.; Soyeur, M.

1995-11-01

We propose a simple meson-exchange model of the photoproduction of ρ-and ω-mesons off protons near threshold (E γ < or∼2 GeV). We show that this model provides a good description of the available data and implies a large ρ-nucleon interaction in the scalar channel (σ-exchange). We use this phenomenological interaction to estimate the leading contribution to the self-energy of ρ-mesons in matter. We discuss the implications of our calculation for experimental studies of the ρ-meson mass in nuclei. (orig.)

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)

Mass spectrum of 1-+ exotic mesons from lattice QCD

International Nuclear Information System (INIS)

Cook, M. S.; Fiebig, H. R.

2006-01-01

Time correlation functions of a hybrid exotic meson operator, with J PC =1 -+ , generated in quenched lattice QCD are subjected to a (Bayesian) maximum entropy analysis. Five distinct spectral levels are uncovered. Their extrapolation into the physical pion mass region suggests a possible relationship to experimentally known states π 1 (1400) and π 1 (1600), and also to a state in the 2 GeV region carrying the same quantum numbers

Search for radiative B meson decays

International Nuclear Information System (INIS)

Lesiak, T.; Muryn, B.; Nowak, G.; Antreasyan, D.; Irion, J.; McBride, P.; Strauch, K.; Bartels, H.W.; Bienlein, J.K.; Brockmueller, K.; Jakubowski, Z.; Karch, K.; Kloiber, T.; Koch, W.; Maschmann, W.; Meyer, H.; Skwarnicki, T.; Trost, H.J.; Voigt, A.; Wachs, K.; Zschorsch, P.; Besset, D.; Cabenda, R.; Cowan, R.; Bieler, C.; Graaf, K.; Heinsius, F.H.; Kiel, T.; Krueger, S.; Lekebusch, R.; Nernst, R.; Sievers, D.; Stock, V.; Strohbusch, U.; Bloom, E.D.; Clare, R.; Cooper, S.; Fairfield, K.; Fridman, A.; Gaiser, J.; Gelphman, D.; Godfrey, G.; Hofstadter, R.; Kirkbride, I.; Lee, R.; Leffler, S.; Litke, A.M.; Lockman, W.; Lowe, S.; Niczyporuk, B.; Pollock, B.; Schwarz, A.; Tompkins, J.; Van Uitert, B.; Wacker, K.; Brock, I.; Engler, A.; Kraemer, R.W.; Marlow, D.; Messing, F.; Prindle, D.; Renger, B.; Rippich, C.; Vogel, H.; Cavalli-Sforza, M.; Coyne, D.; Folger, G.; Glaser, G.; Kobel, M.; Lurz, B.; Schuette, J.; Volland, U.; Wegener, H.; Janssen, H.; Koenig, A.C.; Metzger, W.J.; Reidenbach, M.; Schotanus, J.; Walle, R.T. van de; Walk, W.; Keh, S.; Kilian, H.; Koenigsmann, K.; Scheer, M.; Schmitt, P.; Marsiske, H.; Williams, D.A.

1992-01-01

The Crystal Ball detector at the e + e - 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≤M X ≤2045 MeV. (orig.)

Search for radiative B meson decays

International Nuclear Information System (INIS)

Lesiak, T.; Muryn, B.; Nowak, G.; Antreasyan, D.; Irion, J.; McBride, P.; Strauch, K.; Bartels, H.W.; Bienlein, J.K.; Brockmueller, K.; Jakubowski, Z.; Karch, K.; Kloiber, T.; Koch, W.; Maschmann, W.; Meyer, H.; Skwarnicki, T.; Trost, H.J.; Voigt, A.; Wachs, K.; Zschorsch, P.; Besset, D.; Cabenda, R.; Cowan, R.; Bieler, C.; Graaf, K.; Heinsius, F.H.; Kiel, T.; Krueger, S.; Lekebusch, R.; Nernst, R.; Sievers, D.; Stock, V.; Strohbusch, U.; Bloom, E.D.; Clare, R.; Cooper, S.; Fairfield, K.; Fridman, A.; Gaiser, J.; Gelphman, D.; Godfrey, G.; Hofstadter, R.; Kirkbride, I.; Lee, R.; Leffler, S.; Litke, A.M.; Lockman, W.; Lowe, S.; Niczyporuk, B.; Pollock, B.; Schwarz, A.; Tompkins, J.; Van Uitert, B.; Wacker, K.; Brock, I.; Engler, A.; Kraemer, R.W.; Marlow, D.; Messing, F.; Prindle, D.; Renger, B.; Rippich, C.; Vogel, H.; Cavalli-Sforza, M.; Coyne, D.; Folger, G.; Glaser, G.; Kobel, M.; Lurz, B.; Schuette, J.; Volland, U.; Wegener, H.; Janssen, H.; Koenig, A.C.; Metzger, W.J.; Reidenbach, M.; Schotanus, J.; Walle, R.T. van de; Walk, W.; Keh, S.; Kilian, H.; Koenigsmann, K.; Scheer, M.; Schmitt, P.; Marsiske, H.; Peck, C.; Porter, F.C.; Ratoff, P.; Williams, D.A.

1991-07-01

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≤M X ≤2045 MeV. (orig.)

Measurement of nuclear transparencies from exclusive ρ0 meson production in muon-nucleus scattering

International Nuclear Information System (INIS)

Fang, G.Y.

1995-01-01

Preliminary results on the measurement of nuclear transparencies from exclusive incoherent ρ 0 meson production off deuterium, carbon, calcium, and lead, normalized to hydrogen, and coherent ρ 0 meson production off calcium and lead, normalized to carbon, in deep-inelastic muon-nucleus scattering are reported. The data were collected with the E665 spectrometer using the Fermilab Tevatron muon beam with a mean beam energy of 470 GeV. Increases in the transparencies are observed in both coherent and incoherent production as the virtuality of the photon increases, as expected of color transparency. copyright 1995 American Institute of Physics

Quantum chromodynamics with infinite number of vector mesons

International Nuclear Information System (INIS)

Geshkenbejn, B.V.

1988-01-01

Families of vector mesons Ρ,Ψ,Υ, contain an infinite number of resonances with gradually increasing widths are considered. The asymptotic freedom requirement involves a relationship between the electric width of k-th resonance and its mass M k derivative over the number k. It is shown that for the families of Ψ and Υ mesons the moment from experimental function R(s) is equal to the sum of the moment from a bare quark loop and the edge term which stems from replacing of summation by integration. These equalities are fulfilled up to 1% for 60 moments in the Ψ-meson family and up to 2% for 96 moments in the Υ-meson family. The electronic widths of the resonances and the Ρ-meson mass are calculated. 7 refs

Is a charmed axial-vector meson already found

International Nuclear Information System (INIS)

Matsuda, S.

1976-12-01

A calculation is presented of the production rate via e + e - annihilation for a charmed p-wave meson of Jsup(P) = 1 + , based on a non-relativistic quark model of charmed hadrons. The results strongly suggest that the charmed axial-vector meson should be found copiously in association with a ground-state charmed meson. (author)

The mixing of scalar mesons and the baryon-baryon interaction

International Nuclear Information System (INIS)

Dai, L.R.

2011-01-01

By introducing the mixing of scalar mesons in the chiral SU(3) quark model, we dynamically investigate the baryon-baryon interaction. The hyperon-nucleon and nucleon-nucleon interactions are studied by solving the resonating group method (RGM) equation in a coupled-channel calculation. In our present work, the experimental lightest pseudoscalar π, K, η, η' mesons correspond exactly to the chiral nonet pseudoscalar fields π, K, η, η' in the chiral SU(3) quark model. The η, η' mesons are considered as the mixing of singlet and octet mesons, and the mixing angle θ ps is taken to be -23 . For scalar nonet mesons, we suppose that there exists a correspondence between the experimental lightest scalar f 0 (600), κ, a 0 (980), f 0 (980) mesons and the theoretical scalar nonet σ, κ, σ', ε fields in the chiral SU(3) quark model. For scalar mesons, we consider two different mixing cases: one is the ideal mixing and another is the θ s = 19 mixing. The masses of the σ' and ε mesons are taken to be 980MeV, which are just the masses of the experimental a 0 (980), f 0 (980) mesons. The mass of the σ meson is an adjustable parameter and is decided by fitting the binding energy of the deuteron, the masses of 560MeV and 644MeV are obtained for the ideal mixing and the θ s = 19 mixing, respectively. We find that, in order to reasonably describe the YN interactions, the mass of the κ meson is near 780MeV for the ideal mixing. However, we must enhance the mass of the κ meson for the θ s = 19 mixing, the 1050MeV is favorably used in the present work. The experimental σ and κ scalar mesons are very strange, both have larger widths. Hence, no matter what kind of mixing is considered, all the masses of scalar mesons we used in the present work seem to be consistent with the present PDG information. (orig.)

Nuclear structure studies with pions and light ions: Progress report for the period June 1, 1984-May 31, 1987

International Nuclear Information System (INIS)

Dehnhard, D.

1986-11-01

Pion and proton scattering experiments were done on a variety of nuclei at the Los Alamos Meson Physics Facility. The data were used to test nuclear structure models and models of the pion-nucleus interaction, as well as assumptions about the basic nucleon-nucleon interaction. Included in this report are descriptions of completed work, work in progress, and a list of publications. 63 refs., 24 figs., 1 tab

Measurement of the reaction 12C(νμ,μ-)X near threshold

International Nuclear Information System (INIS)

Albert, M.; Athanassopoulos, C.; Auerbach, L.B.; Bauer, D.; Bolton, R.; Boyd, B.; Burman, R.L.; Cohen, I.; Caldwell, D.O.; Dieterle, B.D.; Donahue, J.B.; Eisner, A.M.; Fazely, A.; Federspiel, F.J.; Garvey, G.T.; Gunasingha, R.M.; Highland, V.; Hill, J.; Imlay, R.; Johnston, K.; Louis, W.C.; Lu, A.; Mann, A.K.

1995-01-01

The reaction 12 C(ν μ ,μ - )X has been measured near threshold using a π + decay-in-flight ν μ beam from the Los Alamos Meson Physics Facility and a massive liquid scintillator neutrino detector (LSND). In the energy region 123.7 ν -40 cm 2 } is more than a factor of 2 lower than that predicted by the Fermi-gas model and by a recent random phase approximation calculation

Transport of radionuclides from the LAMPF lagoons

International Nuclear Information System (INIS)

Ferenbaugh, R.W.; Purtymun, W.D.

1985-01-01

Monitoring of the discharge water from the Los Alamos Meson Physics Facility lagoons continued during June and December of 1983. The list of radionuclides being monitoring includes 7 Be, 57 Co, 134 Cs, 3 H, 54 Mn, 22 Na, and 83 Rb. The sampling locations and the data obtained to date are presented. Movement of radionuclides around the lagoons has been described in a previous report. 1 reference, 1 table

Search for scalar mesons

International Nuclear Information System (INIS)

Pennington, M.R.

1989-01-01

The search for I = 0 0 ++ mesons is described. The crucial role played by the states in the 1 GeV region is highlighted. An analysis program that with unimpeachable data would produce definitive results on these is outlined and shown with present data to provide prima facie evidence for dynamics beyond that of the quark model. The authors briefly speculate on the current status of the lowest mass scalar mesons and discuss how experiment can resolve the unanswered issues. 30 references, 6 figures, 1 table

Fock exchange in meson theories of nuclei

International Nuclear Information System (INIS)

Bolsterli, M.

1986-01-01

The Fock exchange term in meson field theories of nuclear systems is shown to arise from a two-loop ground-state self-energy diagram. Evaluation of this diagram gives the relativistic or semirelativistic analog of the Fock exchange energy; it differs from the nucleon-nucleon Fock energy in including retardation effects. In finite meson-field theories of nuclear systems, the variational nature of the meson-field analog of the Hartree-Fock energy functional can be further elucidated. 4 refs

On some rare weak decays of vector mesons

International Nuclear Information System (INIS)

Kurdadze, L.M.; Silagadze, Z.K.

2000-01-01

Some semileptonic weak decays of vector mesons are considered in the framework of the most popular quark models. Two the most popular models go give more elaborated estimates for the vector meson semileptonic decay rates are used. Unfortunately the predicted branching ratios are too small to make a study of these decays realistic at meson factories under construction [ru

Neutral and charged scalar mesons, pseudoscalar mesons, and diquarks in magnetic fields

Science.gov (United States)

Liu, Hao; Wang, Xinyang; Yu, Lang; Huang, Mei

2018-04-01

We investigate both (pseudo)scalar mesons and diquarks in the presence of external magnetic field in the framework of the two-flavored Nambu-Jona-Lasinio (NJL) model, where mesons and diquarks are constructed by infinite sum of quark-loop chains by using random phase approximation. The polarization function of the quark-loop is calculated to the leading order of 1 /Nc expansion by taking the quark propagator in the Landau level representation. We systematically investigate the masses behaviors of scalar σ meson, neutral and charged pions as well as the scalar diquarks, with respect to the magnetic field strength at finite temperature and chemical potential. It is shown that the numerical results of both neutral and charged pions are consistent with the lattice QCD simulations. The mass of the charge neutral pion keeps almost a constant under the magnetic field, which is preserved by the remnant symmetry of QCD ×QED in the vacuum. The mass of the charge neutral scalar σ is around two times quark mass and increases with the magnetic field due to the magnetic catalysis effect, which is an typical example showing that the polarized internal quark structure cannot be neglected when we consider the meson properties under magnetic field. For the charged particles, the one quark-antiquark loop contribution to the charged π± increases essentially with the increase of magnetic fields due to the magnetic catalysis of the polarized quarks. However, the one quark-quark loop contribution to the scalar diquark mass is negative comparing with the point-particle result and the loop effect is small.

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.)

Meson exchange corrections in deep inelastic scattering on deuteron

International Nuclear Information System (INIS)

Kaptari, L.P.; Titov, A.I.

1989-01-01

Starting with the general equations of motion of the nucleons interacting with the mesons the one-particle Schroedinger-like equation for the nucleon wave function and the deep inelastic scattering amplitude with the meson-exchange currents are obtained. Effective pion-, sigma-, and omega-meson exchanges are considered. It is found that the mesonic corrections only partially (about 60%) restore the energy sum rule breaking because of the nucleon off-mass-shell effects in nuclei. This results contradicts with the prediction based on the calculation of the energy sum rule limited by the second order of the nucleon-meson vertex and static approximation. 17 refs.; 3 figs

Unified Chiral models of mesons and baryons

International Nuclear Information System (INIS)

Mendez-Galain, R.; Ripka, G.

1990-01-01

Unified Chiral models of mesons and baryons are presented. Emphasis is placed on the underlying quark structure of hadrons including the Skyrmion. The Nambu Jona-Lasinio model with vector mesons is discussed

Search for gluonic excitations in light unconventional mesons

Energy Technology Data Exchange (ETDEWEB)

Paul Eugenio

2007-07-01

Studies of meson spectra via strong decays provide insight regarding QCD at the confinement scale. These studies have led to phenomenologicalmodels for QCD such as the constituent quark model. However, QCD allows for a much richer spectrum of meson states which include extra states such as exotics, hybrids, multi-quarks, and glueballs. First discussion of the status of exotic meson searches is given followed by a discussion of plans at Jefferson Lab to double the energy of the machine to 12 GeV, which will allow us to access photoproduction of mesons in search for gluonic excited states.

Sigma meson in heavy ion collision

International Nuclear Information System (INIS)

Cristian, Ivan; Fuchs, Christian

2004-01-01

We want to present a short theoretical prediction of the behaviour of the sigma meson in heavy ion collisions. It is considered that the sigma meson is a pion-pion correlation, resulting from the decay of the N*(1440) resonance. There will be presented some QMD simulations. (authors)

Research in experimental nuclear physics: Progress report, April 1, 1988--March 31, 1989

International Nuclear Information System (INIS)

Moore, C.F.

1988-11-01

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 1987 under grant AS05-87ER40343 between The University of Texas at Austin and the United States Department of Energy. The research activities involved experiments done with the Energetic Pion Channel and Spectrometer (EPICS), the Low Energy Pion Channel (LEP), the Pion and Particle Physics Channel (P 3 ), and the High Resolution Spectrometer (HRS). A brief overview of work supported by this grant is given. This report contains a list of abstracts of papers reported at scientific meetings, a list of invited papers, and a list of published papers and preprints. These papers summarize experiments undertaken in this grant period and indicate the work accomplished by the participants in this program of medium energy nuclear physics research. Much of the experimental work that has been attempted during the period covered by this report has either been published or submitted for publication. Also included is a list of the recent proposals on which we have participation at LAMPF, and a list of personnel who have participated in this research program

Preliminary results with the CLAMSUD pion spectrometer at the Moscow Meson Factory

International Nuclear Information System (INIS)

Badala, A.; Barbera, R.; Librizzi, F.; Longhitano, A.; Nicotra, D.; Palmeri, A.; Pappalardo, G.S.; Riggi, F.; Santoro, A.; Turrisi, R.; Aseev, V.; Feschenko, A.; Gavrilov, Yu.; Guber, F.; Golubeva, M.; Karavicheva, T.; Kurepin, A.; Ostroumov, P.; Potapov, V.; Tiflov, V.; Zhuravlev, A.

1995-01-01

A magnetic spectrometer has been recently installed at the new proton beam facility of the Moscow Meson Factory, to study charged pion production from proton-nucleus interactions at 200-400 MeV bombarding energy. Preliminary reults obtained during the first runs are reported. The planned physics program is also discussed. (orig.)

Old tensor mesons in QCD sum rules

International Nuclear Information System (INIS)

Aliev, T.M.; Shifman, M.A.

1981-01-01

Tensor mesons f, A 2 and A 3 are analyzed within the framework of QCD sum rules. The effects of gluon and quark condensate is accounted for phenomenologically. Accurate estimates of meson masses and coupling constants of the lowest-lying states are obtained. It is shown that the masses are reproduced within theoretical uncertainty of about 80 MeV. The coupling of f meson to the corresponding quark current is determined. The results are in good aqreement with experimental data [ru

Why do nucleons cling. [Meson theory

Energy Technology Data Exchange (ETDEWEB)

Kumar, N [Hindu Coll., Delhi (India)

1976-10-01

The nature of the forces which bind nucleons together within the nucleus of an atom have been discussed in detail. The characteristic properties of the nucleons, such as spin, interaction range etc. and the meson theory of nuclear forces are described. The present researches indicate that the force between two nucleons in a many-nucleon system is not very different from the force between two free nucleons. Researches related to the origin of nuclear forces based on the meson theory are now mainly concerned with the role played by the heavier mesons and the two pion exchanges in the middle region around 0.7 fm. (10/sup -13/ cm).

Single meson photoproduction and IR renormalons

International Nuclear Information System (INIS)

Agaev, S.S.

1996-10-01

Single pseudoscalar and vector mesons inclusive photoproduction γh → MX via higher twist mechanism is calculated using the QCD running coupling constant method. It is proved that in the context of this method a higher twist contribution to the photoproduction cross section cannot be normalized in terms of the meson electromagnetic form factor. The structure of infrared renormalon singularities of the higher twist subprocess cross section and the resumed expression (the Borel sum) for it are found. Comparisons are made with earlier results, as well as with leading twist cross section. Phenomenological effects of studied contributions for π, K, ρ-meson photoproduction are discussed. (author). 21 refs, 8 figs

Production and decay rates of the iota meson

International Nuclear Information System (INIS)

Frank, M.; O'Donnell, P.J.; Toronto Univ., Ontario

1984-01-01

We correlate the results for the mass spectrum of low lying isoscalar-pseudoscalar mesons with the production decay rates from J/psi->γP, with P=eta 1 , eta' 1 , eta 2 and iota and study the radiative decays of the iota meson. We conclude that the iota meson has to be interpreted as having a strong gluonium component. (orig.)

Publications of Los Alamos research, 1977-1981

International Nuclear Information System (INIS)

Sheridan, C.J.; Garcia, C.A.

1983-03-01

This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1977-1981. Papers published in those years are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them

Publications of Los Alamos research, 1977-1981

Energy Technology Data Exchange (ETDEWEB)

Sheridan, C.J.; Garcia, C.A. (comps.)

1983-03-01

This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1977-1981. Papers published in those years are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

The mixing of scalar mesons and the baryon-baryon interaction

Energy Technology Data Exchange (ETDEWEB)

Dai, L.R. [Liaoning Normal University, Department of Physics, Dalian (China)

2011-02-15

By introducing the mixing of scalar mesons in the chiral SU(3) quark model, we dynamically investigate the baryon-baryon interaction. The hyperon-nucleon and nucleon-nucleon interactions are studied by solving the resonating group method (RGM) equation in a coupled-channel calculation. In our present work, the experimental lightest pseudoscalar {pi}, K, {eta}, {eta}' mesons correspond exactly to the chiral nonet pseudoscalar fields {pi}, K, {eta}, {eta}' in the chiral SU(3) quark model. The {eta}, {eta}' mesons are considered as the mixing of singlet and octet mesons, and the mixing angle {theta}{sub ps} is taken to be -23 . For scalar nonet mesons, we suppose that there exists a correspondence between the experimental lightest scalar f{sub 0}(600), {kappa}, a{sub 0}(980), f{sub 0}(980) mesons and the theoretical scalar nonet {sigma}, {kappa}, {sigma}', {epsilon} fields in the chiral SU(3) quark model. For scalar mesons, we consider two different mixing cases: one is the ideal mixing and another is the {theta}{sub s} = 19 mixing. The masses of the {sigma}' and {epsilon} mesons are taken to be 980MeV, which are just the masses of the experimental a{sub 0}(980), f{sub 0}(980) mesons. The mass of the {sigma} meson is an adjustable parameter and is decided by fitting the binding energy of the deuteron, the masses of 560MeV and 644MeV are obtained for the ideal mixing and the {theta}{sub s} = 19 mixing, respectively. We find that, in order to reasonably describe the YN interactions, the mass of the {kappa} meson is near 780MeV for the ideal mixing. However, we must enhance the mass of the {kappa} meson for the {theta}{sub s} = 19 mixing, the 1050MeV is favorably used in the present work. The experimental {sigma} and {kappa} scalar mesons are very strange, both have larger widths. Hence, no matter what kind of mixing is considered, all the masses of scalar mesons we used in the present work seem to be consistent with the present PDG information

Los Alamos Neutron Science Center

Energy Technology Data Exchange (ETDEWEB)

Kippen, Karen Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-11-08

For more than 30 years the Los Alamos Neutron Science Center (LANSCE) has provided the scientific underpinnings in nuclear physics and material science needed to ensure the safety and surety of the nuclear stockpile into the future. In addition to national security research, the LANSCE User Facility has a vibrant research program in fundamental science, providing the scientific community with intense sources of neutrons and protons to perform experiments supporting civilian research and the production of medical and research isotopes. Five major experimental facilities operate simultaneously. These facilities contribute to the stockpile stewardship program, produce radionuclides for medical testing, and provide a venue for industrial users to irradiate and test electronics. In addition, they perform fundamental research in nuclear physics, nuclear astrophysics, materials science, and many other areas. The LANSCE User Program plays a key role in training the next generation of top scientists and in attracting the best graduate students, postdoctoral researchers, and early-career scientists. The U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA) —the principal sponsor of LANSCE—works with the Office of Science and the Office of Nuclear Energy, which have synergistic long-term needs for the linear accelerator and the neutron science that is the heart of LANSCE.

RCRA facility investigation for the townsite of Los Alamos, New Mexico

International Nuclear Information System (INIS)

Dorries, A.M.; Conrad, R.C.; Nonno, L.M.

1992-01-01

During World War II, Los Alamos, New Mexico was established as an ideal location for the secrecy and safety needed for the research and development required to design a nuclear fission bomb. Experiments carried out in the 1940s generated both radioactive and hazardous waste constituents on what is presently part of the Los Alamos townsite. Under the RCRA permit issued to Los alamos national Laboratory in 1990, the Laboratory is scheduled for investigation of its solid waste management units (SWMUs). The existing information on levels of radioactivity on the townsite is principally data from soil samples taken during the last site decontamination in 1976, little information on the presence of hazardous constituents exists today. This paper addresses pathway analysis and a preliminary risk assessment for current residents of the Los Alamos townsite. The estimated dose levels, in mrem per year, show that the previously decontaminated SWMU areas on the Los Alamos townsite will not contribute a radiation dose of any concern to the current residents

Radiative decays of vector mesons in the chiral bag model

International Nuclear Information System (INIS)

Tabachenko, A.N.

1988-01-01

A new model of radiative π-meson decays of vector mesons in the chiral bag model is proposed. The quark-π-meson interaction has the form of a pseudoscalar coupling and is located on the bag surface. The vector meson decay width depends on the quark masses, the π-meson decay constant, the radius of the bag, and the free parameter Z 2 , which specifies the disappearance of the bag during the decay. The obtained results for the omega- and p-decay widths are in satisfactory agreement with the experiment

Inclusive spectra of hadrons in B-meson decays

International Nuclear Information System (INIS)

Dobrovol'skaya, A.V.; Ter-Martirosyan, K.A.; Zoller, V.R.

1989-01-01

The inclusive spectra of hadrons (mainly pions) produced in the semileptonic and nonleptonic decays of B-mesons are calculated. Parameters of spectra for different types of hard qq-bar-strings, appearing in the B-meson decays, are determined using the data on e+e-annihilation. Numerical results for B-meson decay induced by both b→b and b→u transitions are presented. 10 refs.; 5 figs

Recent progress in the Los Alamos KrF Program

International Nuclear Information System (INIS)

McDonald, T.E.; Cartwright, D.C.; Coggeshall, S.V.

1988-01-01

The goal of the Inertial Confinement Fusion Program (ICF) is to develop the ability to ignite and burn small masses of thermonuclear fuel. Although the present near-term objectives of the program are directed toward defense applications, ICF research continues to be carried out with a view to the longer term goal of commercial power production. The characteristics of a KrF laser make it an attractive candidate as an ICF driver. The KrF wavelength of 248 nm provides a target coupling that is very high at intensities of 10 14 w/cm 2 . In addition, the KrF laser can be repetitively operated at frequencies appropriate for a power reactor and has an intrinsically high efficiency, which allows projections to the long-term goal of energy production. The ICF program at Los Alamos consists of driver development, target design and fabrication, and target experimentation. The major effort at present is the investigation and development of KrF technology to determine its applicability for use in a laboratory driver at Los Alamos. Such a driver would be used in defense related technology studies and in areas of scientific study such as highly ionized materials and high-energy-density physics

Omega meson production in proton-proton collisions

International Nuclear Information System (INIS)

Schulte-Wissermann, M.; Brinkmann, K.; Dshemuchadse, S.

2005-01-01

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

Summary of research for the Inertial Confinement Fusion Program at Los Alamos National Laboratory

International Nuclear Information System (INIS)

Cartwright, D.C.

1985-03-01

The information presented in this report is a summary of the status of the Inertial Confinement Fusion (ICF) program at the Los Alamos National Laboratory as of February 1985. This report contains material on the existing high-power CO 2 laser driver (Antares), the program to determine the potential of KrF as an ICF driver, heavy-ion accelerators as drivers for ICF, target fabrication for ICF, and a summary of our understanding of laser-plasma interactions. A classified companion report contains material on our current understanding of capsule physics and lists the contributions to the Laboratory's weapons programs made by the ICF program. The information collected in these two volumes is meant to serve as a report on the status of some of the technological components of the Los Alamos ICF program rather than a detailed review of specific technical issues

SACLAY: Eta mesons at Saturne

Energy Technology Data Exchange (ETDEWEB)

Anon.

1992-05-15

Using a nuclear reaction, the new tagged eta meson facility now operating at the French Saturne National Laboratory in Saclay produces eta mesons (together with recoil helium-3 nuclei) by proton bombardment of a deuterium target. The proton beam is extracted from the Saturne synchrotron at 893 MeV, stabilized to 80 keV. This is a scant 1.5 MeV above the reaction threshold and close to the energy where eta production peaks.

SACLAY: Eta mesons at Saturne

International Nuclear Information System (INIS)

Anon.

1992-01-01

Using a nuclear reaction, the new tagged eta meson facility now operating at the French Saturne National Laboratory in Saclay produces eta mesons (together with recoil helium-3 nuclei) by proton bombardment of a deuterium target. The proton beam is extracted from the Saturne synchrotron at 893 MeV, stabilized to 80 keV. This is a scant 1.5 MeV above the reaction threshold and close to the energy where eta production peaks

Multistrange Meson-Baryon Dynamics and Resonance Generation

Science.gov (United States)

Khemchandani, K. P.; Martínez Torres, A.; Hosaka, A.; Nagahiro, H.; Navarra, F. S.; Nielsen, M.

2018-05-01

In this talk I review our recent studies on meson-baryon systems with strangeness - 1 and - 2. The motivation of our works is to find resonances generated as a consequence of coupled channel meson-baryon interactions. The coupled channels are all meson-baryon systems formed by combining a pseudoscalar or a vector meson with an octet baryon such that the system has the strange quantum number equal to - 1 or - 2. The lowest order meson-baryon interaction amplitudes are obtained from Lagrangians based on the chiral and the hidden local symmetries related to the vector mesons working as the gauge bosons. These lowest order amplitudes are used as an input to solve the Bethe-Salpeter equation and a search for poles is made in the resulting amplitudes, in the complex plane. In case of systems with strangeness - 1, we find evidence for the existence of some hyperons such as: Λ(2000), Σ(1750), Σ(1940), Σ(2000). More recently, in the study of strangeness - 2 systems we have found two narrow resonances which can be related to Ξ (1690) and Ξ(2120). In this latter work, we have obtained the lowest order amplitudes relativistically as well as in the nonrelativistic approximation to solve the scattering equations. We find that the existence of the poles in the complex plane does not get affected by the computation of the scattering equation with the lowest order amplitudes obtained in the nonrelativistic approximation.

Discovery of massive neutral vector mesons

International Nuclear Information System (INIS)

Anon.

1976-01-01

Personal accounts of the discovery of massive neutral vector mesons (psi particles) are given by researchers S. Ting, G. Goldhaber, and B. Richter. The double-arm spectrometer and the Cherenkov effect are explained in a technical note, and the solenoidal magnetic detector is discussed in an explanatory note for nonspecialists. Reprints of three papers in Physical Review Letters which announced the discovery of the particles are given: Experimental observation of a heavy particle J, Discovery of a narrow resonance in e + e - annihilation, and Discovery of a second narrow resonance in e + e - annihilation. A discussion of subsequent developments and scientific biographies of the three authors are also presented. 25 figures

Relativistic meson spectroscopy in momentum space

International Nuclear Information System (INIS)

Hersbach, H.

1994-01-01

In this paper a relativistic constituent-quark model based on the Ruijgrok--de Groot formalism is presented. The quark model is not defined in configuration space, but in momentum space. The complete meson spectrum, with the exception of the self-conjugate light unflavored mesons, is calculated. The potential used consists of a one-gluon exchange (OGE) part and a confining part. For the confining part a relativistic generalization of the linear plus constant potential was used, which is well defined in momentum space without introducing any singularities. For the OGE part several potentials were investigated. Retardations were included at all places. By the use of a fitting procedure involving 52 well-established mesons, but results were obtained for a potential consisting of a purely vector Richardson potential and a purely scalar confining potential. Reasonable results were also obtained for a modified Richardson potential. Most meson masses, with the exception of the π, the K, and the K 0 * , were found to be quite well described by the model

Asymptotics of Heavy-Meson Form Factors

CERN Document Server

Grozin, A.G.; Grozin, Andrey G.; Neubert, Matthias

1997-01-01

Using methods developed for hard exclusive QCD processes, we calculate the asymptotic behaviour of heavy-meson form factors at large recoil. It is determined by the leading- and subleading-twist meson wave functions. For $1\\ll |v\\cdot v'|\\ll m_Q/\\Lambda$, the form factors are dominated by the Isgur--Wise function, which is determined by the interference between the wave functions of leading and subleading twist. At $|v\\cdot v'|\\gg m_Q/\\Lambda$, they are dominated by two functions arising at order $1/m_Q$ in the heavy-quark expansion, which are determined by the leading-twist wave function alone. The sum of these contributions describes the form factors in the whole region $|v\\cdot v'|\\gg 1$. As a consequence, there is an exact zero in the form factor for the scattering of longitudinally polarized $B^*$ mesons at some value $v\\cdot v'\\sim m_b/\\Lambda$, and an approximate zero in the form factor of $B$ mesons in the timelike region ($v\\cdot v'\\sim -m_b/\\Lambda$). We obtain the evolution equations and sum rules ...

Estimating mass of σ-meson and study on application of the linear σ-model

International Nuclear Information System (INIS)

Ding Yibing; Li Xin; Li Xueqian; Liu Xiang; Shen Hong; Shen Pengnian; Wang Guoli; Zeng Xiaoqiang

2004-01-01

Whether the σ-meson (f 0 (600)) exists as a real particle is a long-standing problem in both particle physics and nuclear physics. In this work, we analyse the deuteron binding energy in the linear σ-model and by fitting the data, we are able to determine the range of m σ and also investigate applicability of the linear σ-model for the interaction between hadrons in the energy region of MeVs. Our result shows that the best fit to the data of the deuteron binding energy and others advocates a narrow range for the σ-meson mass as 520 ≤ m σ ≤ 580 MeV and the concrete values depend on the input parameters such as the couplings. Inversely by fitting the experimental data, one can set constraints on the couplings and the other relevant phenomenological parameters in the model

Two-Body B Meson Decays to η and η' : Observation of B→η'K

International Nuclear Information System (INIS)

Behrens, B.H.; Ford, W.T.; Gritsan, A.; Krieg, H.; Roy, J.; Smith, J.G.; Zhao, M.; Alexander, J.P.; Baker, R.; Bebek, C.; Berger, B.E.; Berkelman, K.; Bloom, K.; Boisvert, V.; Cassel, D.G.; Crowcroft, D.S.; Dickson, M.; Dombrowski, S. von; Drell, P.S.; Ecklund, K.M.; Ehrlich, R.; Foland, A.D.; Gaidarev, P.; Gibbons, L.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Hopman, P.I.; Kandaswamy, J.; Kim, P.C.; Kreinick, D.L.; Lee, T.; Liu, Y.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Ogg, M.; Patterson, J.R.; Peterson, D.; Riley, D.; Soffer, A.; Valant-Spaight, B.; Ward, C.; Athanas, M.; Avery, P.; Jones, C.D.; Lohner, M.; Patton, S.; Prescott, C.; Yelton, J.; Zheng, J.; Brandenburg, G.; Briere, R.A.; Ershov, A.; Gao, Y.S.; Kim, D.Y.; Wilson, R.; Yamamoto, H.; Browder, T.E.; Li, Y.; Rodriguez, J.L.; Bergfeld, T.; Eisenstein, B.I.; Ernst, J.; Gladding, G.E.; Gollin, G.D.; Hans, R.M.; Johnson, E.; Karliner, I.; Marsh, M.A.; Palmer, M.; Selen, M.; Thaler, J.J.; Edwards, K.W.; Edwards, K.W.; Bellerive, A.; Bellerive, A.; Janicek, R.; Janicek, R.; MacFarlane, D.B.; MacFarlane, D.B.; Patel, P.M.; Patel, P.M.; Sadoff, A.J.; Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Darling, C.; Davis, R.; Kotov, S.; Kravchenko, I.; Kwak, N.; Zhou, L.; Anderson, S.; Kubota, Y.; Lee, S.J.; ONeill, J.J.; Poling, R.; Riehle, T.

1998-01-01

In a sample of 6.6x10 6 produced B mesons we have observed decays B→η ' K , with branching fractions B(B + →η ' K + )=(6.5 +1.5 -1.4 ±0.9)x10 -5 and B(B 0 →η ' K 0 )=(4.7 +2.7 -2.0 ±0.9)x10 -5 . We have searched with comparable sensitivity for 17 related decays to final states containing an η or η ' meson accompanied by a single particle or low-lying resonance. Our upper limits for these constrain theoretical interpretations of the B→η ' K signal. copyright 1998 The American Physical Society

C(1480) meson and electromagnetic processes

International Nuclear Information System (INIS)

Landsberg, L.G.

1992-01-01

Possible processes of production of the vector meson C(1480) → var-phi π, a candidate for exotic states, in electromagnetic processes are considered [photoproduction, e + e - →C(1480) → var-phi π 0 , and the reaction of production of C(1480) in the Coulomb field of a nucleus]. It is shown that coherent Coulomb production of the C(1480) meson allows one to determine the absolute value of BR[C(1480) → var-phi π], which is essential for the interpretation of the nature of this hadron. Possibilities of observing C(1480) mesons in e + e - collisions at the var-phi factory DAΦNE are studied. 27 refs., 12 figs., 1 tab

Radiative decay of light and heavy mesons

International Nuclear Information System (INIS)

Barik, N.; Dash, P.C.

1994-01-01

The M1 transition among the vector (V) and pseudoscalar (P) mesons in the light and heavy flavor sectors has been investigated in a potential model of independent quarks. Going beyond the static approximation, to add some momentum dependence due to the recoil effect in a more realistic calculation, we find an improvement in the results for the radiative decay of light flavored mesons. However, our prediction on the decay rates for the mesons (D * and B * ) in the heavy flavor sector remains unaffected and compares well with those of other model calculations

In-medium meson properties and screening correlators

International Nuclear Information System (INIS)

Bazavov, A; Karsch, F; Mukherjee, Swagato; Petreczky, P; Maezawa, Y

2014-01-01

We study spatial meson correlation functions consisting of strange quarks, strange and charm quarks and charm quarks in (2 + 1)-flavor QCD using the highly improved staggered quark action. We find that the in-medium modification of the meson correlators decreases with increasing charm quark content and decreasing size. In particular, we find strong in-medium modification of φ and D s meson correlators around the chiral transition temperature T c , while J/ψ and η c correlators show strong in-medium modification only at temperatures of 1.4T c .

Vector mesons in meson-baryon scattering and large-N_c quantum chromodynamics

International Nuclear Information System (INIS)

Fuhrmann, Hans-Friedrich

2016-01-01

We examined strong interactions in the low-energy regime in terms of two complementary non-perturbative approaches: the interplay of large-N_c QCD and chiral perturbation theory was studied. While the expansion in the parameter 1/N_c is based on quark and gluon degrees of freedom, chiral perturbation theory uses hadrons as effective degrees of freedom. The focus of our work was the investigation of mesons and baryons composed from up-, down- and strange quarks. We used the chiral SU(3) Lagrangian with (J"P=(1)/(2)"+)- and (J"P=(3)/(2)"+)-baryon ground states as building blocks. In the SU(3)-flavour limit the latter form an octet and a decuplet, respectively. Studies in chiral perturbation theory hold a challenge: the chiral Lagrangian consists of an infinite number of terms. The treatment of low-energy QCD physics via a perturbation theory requires the ordering of these terms according to their relevance. We used the interplay between large-N_c QCD and chiral perturbation theory to shed light on the structure of the chiral Lagrangian. In the limit of large-N_c the low-energy parameters of the chiral Lagrangian are correlated. For instance the masses of the two baryon multiplets turn degenerate in the SU(3)-flavour limit. This serves as the starting point of our investigations. In this work we analysed the time-ordered product of two scalar and two vector currents in the baryon ground state. The examination of these matrix elements at large-N_c was compared to corresponding results derived in chiral perturbation theory. From this we obtained sum rules for some low-energy parameters of the chiral Lagrangian. The results for the vector correlation function were used to constrain a phenomenological interaction of light vector mesons with the baryon ground states. In the second part of this thesis we addressed a formal problem which arises in a partial wave decomposition of reaction amplitudes for particles with non-vanishing spin. In particular we considered the vector

Neutral meson tests of time-reversal symmetry invariance

OpenAIRE

Bevan, Adrian; Inguglia, Gianluca; Zoccali, Michele

2013-01-01

The laws of quantum physics can be studied under the mathematical operation T that inverts the direction of time. Strong and electromagnetic forces are known to be invariant under temporal inversion, however the weak force is not. The BaBar experiment recently exploited the quantum-correlated production of pairs of B0 mesons to show that T is a broken symmetry. Here we show that it is possible to perform a wide range of tests of quark flavour changing processes under T in order to validate th...

Review of meson resonance radiative decays

International Nuclear Information System (INIS)

Thorndike, E.H.

1977-01-01

The radiative decays of meson resonances can be studied by three different approaches, it is noted. These are the meson-exchange, Primakoff effect, and the production of the desired resonance and subsequent observation of its decay. These approaches are criticized and examples of them are reviewed. Mass distributions are shown and branching ratios discussed. 21 references

Bound on dissipative effects from semileptonic neutral B-meson decays

Energy Technology Data Exchange (ETDEWEB)

Benatti, F.; Marcantoni, S.; Pinotti, P.; Zimmermann, K. [Universita di Trieste, Dipartimento di Fisica, Trieste (Italy); Istituto Nazionale di Fisica Nucleare, Trieste (Italy); Floreanini, R. [Istituto Nazionale di Fisica Nucleare, Trieste (Italy)

2017-09-15

The semileptonic decay asymmetry A{sub Δm} is studied within the open quantum systems approach to the physics of the neutral meson B{sup 0}-B{sup 0} system: this extended treatment takes into account possible non-standard, dissipative effects induced by the presence of an external environment. A bound on these effects is provided through the analysis of available experimental data from the Belle Collaboration. (orig.)

The liquid scintillator neutrino detector and LAMPF neutrino source

Energy Technology Data Exchange (ETDEWEB)

Athanassopoulos, C.; Auerbach, L.B.; Bauer, D.; Bolton, R.D.; Burman, R.L.; Cohen, I.; Caldwell, D.O.; Dieterle, B.D.; Donahue, J.B.; Eisner, A.M.; Fazely, A.; Federspiel, F.J.; Garvey, G.T.; Gray, M.; Gunasingha, R.M.; Highland, V.; Imlay, R.; Johnston, K.; Kim, H.J.; Louis, W.C.; Lu, A.; Margulies, J.; Mills, G.B.; McIlhany, K.; Metcalf, W.; Reeder, R.A.; Sandberg, V.; Schillaci, M.; Smith, D.; Stancu, I.; Strossman, W.; Tayloe, R.; VanDalen, G.J.; Vernon, W.; Wang, Y.-X.; White, D.H.; Whitehouse, D.; Works, D.; Xiao, Y.; Yellin, S. [California Univ., Riverside, CA (United States)]|[University of California, San Diego, CA 92093 (United States)]|[University of California, Santa Barbara, CA 93106 (United States)]|[University of California, Intercampus Institute for Research at Particle Accelerators, Stanford, CA 94309 (United States)]|[Embry Riddle Aeronautical University, Prescott, AZ 86301 (United States)]|[Linfield College, McMinnville, OR 97128 (United States)]|[Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)]|[Louisiana State University, Baton Rouge, LA 70803 (United States)]|[Louisiana Tech University, Ruston, LA 71272 (United States)]|[University of New Mexico, Albuquerque, NM 87131 (United States)]|[Southern University, Baton Rouge, LA 70813 (United States)]|[Temple University, Philadelphia, PA 19122 (United States)

1997-03-21

A search for neutrino oscillations of the type {nu}{sub {mu}}{yields}{nu}{sub e} has been conducted at the Los Alamos Meson Physics Facility using {nu}{sub {mu}} from muon decay at rest. Evidence for this transition has been reported previously. This paper discusses in detail the experimental setup, detector operation and neutrino source, including aspects relevant to oscillation searches in the muon decay-at-rest and pion decay in flight channels. (orig.).

Meson masses and decay constants from unquenched lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); McNeile, C. [Glasgow Univ. (United Kingdom). Dept. of Physics and Astronomy; Michael, C. [Liverpool Univ. (United Kingdom). Theoretical Physics Div., Dept. of Mathematical Sciences; Urbach, C. [Humboldt Univ. Berlin (Germany). Inst. fuer Physik

2009-06-15

We report results for the masses of the flavour non-singlet light 0{sup ++}, 1{sup --}, and 1{sup +-} mesons from unquenched lattice QCD at two lattice spacings. The twisted mass formalism was used with two flavours of sea quarks. For the 0{sup ++} and 1{sup +-} mesons we look for the effect of decays on the mass dependence. For the light vector mesons we study the chiral extrapolations of the mass. We report results for the leptonic and transverse decay constants of the meson. We test the mass dependence of the KRSF relations. (orig.)

Meson masses and decay constants from unquenched lattice QCD

International Nuclear Information System (INIS)

Jansen, K.; McNeile, C.; Michael, C.; Urbach, C.

2009-06-01

We report results for the masses of the flavour non-singlet light 0 ++ , 1 -- , and 1 +- mesons from unquenched lattice QCD at two lattice spacings. The twisted mass formalism was used with two flavours of sea quarks. For the 0 ++ and 1 +- mesons we look for the effect of decays on the mass dependence. For the light vector mesons we study the chiral extrapolations of the mass. We report results for the leptonic and transverse decay constants of the meson. We test the mass dependence of the KRSF relations. (orig.)

Inclusive decays of the B meson and possible life-time difference between Bd0 and B± mesons

International Nuclear Information System (INIS)

Tanimoto, Morimitsu

1992-01-01

We study branching ratios of the inclusive semileptonic decay and the inclusive anti ccanti s decay of the B meson in the spectator model, focusing on the life-time difference between B d 0 and B + mesons. In the case of τsub(B ± )/τsub(B d 0 )=1, it is impossible to get the branching ratio below 12% for B→eνX without going over 20% for B→anti ccanti s, which is unfavored by the inclusive K - decay of the B meson. It is found that the sizable life-time difference leads to the reasonable inclusive semileptonic decay rate and the inclusive anti ccanti s decay rate. (orig.)

Observation and study of bottom-meson decays to a charm meson, a proton-antiproton pair, and pions

Energy Technology Data Exchange (ETDEWEB)

Hong, Tae Min [Univ. of California, Santa Barbara, CA (United States)

2010-04-27

Bottom-meson decays with baryons show two unusual features—the branching fractions are enhanced for multibody decays and the baryon-antibaryon subsystem recoils against the other decay products—and their reasons are not yet well understood. Moreover, measurements using explicit reconstruction techniques constitute only about 1% out of about 8% of such decays. This Dissertation reports the study of ten bottom-meson decays (labeled 0– 9) to a proton-antiproton pair, a charm meson, and a system of up to two pions, using the BABAR Experiment’s 455×10⁶ BB pairs produced with the PEP-II asymmetric-energy e⁺e^- collider at the Stanford Linear Accelerator Center.

CORNELL: CLEO discovers B meson penguins

Energy Technology Data Exchange (ETDEWEB)

Anon.

1993-06-15

The CLEO collaboration at Cornell's CESR electron-positron storage ring has discovered a rare type of B meson decay in which only a high energy photon and a K* meson are produced. These decays provide the first unambiguous evidence for an alternative route for heavy quark decay that has been given the whimsical name ''penguin diagram''. In the mid-1970s penguin diagrams were proposed to explain the puzzling strangeness quantum number selection rules in the decay of K mesons. At the same time it was realized that penguin diagrams could also be important in the CP violation seen in neutral K meson decay. CP violation, an asymmetry between matter and antimatter, is an essential ingredient in understanding why there is much more matter than antimatter in the universe. CP violation introduces a definite direction to the arrow of time, which could otherwise point equally forwards or backwards. In addition, penguin decays are very sensitive to some extensions of the Standard Model of weak decay. Although penguin diagrams were first proposed to explain an effect in K meson decay, the K system gives no unique signature for them, and verification of penguin processes meant looking elsewhere. In the Standard Model, quarks decay under the influence of the weak force, emitting a W boson. Since the W is charged, the charge of the initial quark differs from that of the final quark, so the charge of the quark changes as well as its flavour.

Medium modifications of mesons. Chiral symmetry restoration, in-medium QCD sum rules for D and ρ mesons, and Bethe-Salpeter equations

Energy Technology Data Exchange (ETDEWEB)

Hilger, Thomas Uwe

2012-04-11

The interplay of hadron properties and their modification in an ambient nuclear medium on the one hand and spontaneous chiral symmetry breaking and its restoration on the other hand is investigated. QCD sum rules for D and B mesons embedded in cold nuclear matter are evaluated. We quantify the mass splitting of D- anti D and B- anti B mesons as a function of the nuclear matter density and investigate the impact of various condensates in linear density approximation. The analysis also includes D{sub s} and D{sup *}{sub 0} mesons. QCD sum rules for chiral partners in the open-charm meson sector are presented at nonzero baryon net density or temperature. We focus on the differences between pseudo-scalar and scalar as well as vector and axial-vector D mesons and derive the corresponding Weinberg type sum rules. Based on QCD sum rules we explore the consequences of a scenario for the ρ meson, where the chiral symmetry breaking condensates are set to zero whereas the chirally symmetric condensates remain at their vacuum values. The complementarity of mass shift and broadening is discussed. An alternative approach which utilizes coupled Dyson-Schwinger and Bethe-Salpeter equations for quark-antiquark bound states is investigated. For this purpose we analyze the analytic structure of the quark propagators in the complex plane numerically and test the possibility to widen the applicability of the method to the sector of heavy-light mesons in the scalar and pseudo-scalar channels, such as the D mesons, by varying the momentum partitioning parameter. The solutions of the Dyson-Schwinger equation in the Wigner-Weyl phase of chiral symmetry at nonzero bare quark masses are used to investigate a scenario with explicit but without dynamical chiral symmetry breaking.

Review of liquid metal heat pipe work at Los Alamos

International Nuclear Information System (INIS)

Reid, R.S.; Merrigan, M.A.; Sena, J.T.

1990-01-01

A survey of space-power related liquid metal heat pipe work at Los Alamos National Laboratory is presented. Heat pipe development at Los Alamos has been on-going since 1963. Heat pipes were initially developed for thermionic nuclear-electrical power production in space. Since then Los Alamos has developed liquid metal heat pipes for numerous applications related to high temperature systems in both the space and terrestrial environments. Some of these applications include thermionic electrical generators, thermoelectric energy conversion (both in-core and direct radiation), thermal energy storage, hypersonic vehicle leading edge cooling, and heat pipe vapor laser cells. Some of the work performed at Los Alamos has been documented in internal reports that are often little-known. A representative description and summary of progress in space-related liquid metal heat pipe technology is provided followed by a reference section citing sources where these works may be found. 53 refs

Coupled Weather and Wildfire Behavior Modeling at Los Alamos: An Overview

Energy Technology Data Exchange (ETDEWEB)

Bossert, James E.; Harlow, Francis H.; Linn, Rodman R.; Reisner, Jon M.; White, Andrew B.; Winterkamp, Judith L.

1997-12-31

Over the past two years, researchers at Los Alamos National Laboratory (LANL) have been engaged in coupled weather/wildfire modeling as part of a broader initiative to predict the unfolding of crisis events. Wildfire prediction was chosen for the following reasons: (1) few physics-based wild-fire prediction models presently exist; (2) LANL has expertise in the fields required to develop such a capability; and (3) the development of this predictive capability would be enhanced by LANL`s strength in high performance computing. Wildfire behavior models have historically been used to predict fire spread and heat release for a prescribed set of fuel, slope, and wind conditions (Andrews 1986). In the vicinity of a fire, however, atmospheric conditions are constantly changing due to non-local weather influences and the intense heat of the fire itself. This non- linear process underscores the need for physics-based models that treat the atmosphere-fire feedback. Actual wildfire prediction with full-physics models is both time-critical and computationally demanding, since it must include regional- to local-scale weather forecasting together with the capability to accurately simulate both intense gradients across a fireline, and atmosphere/fire/fuel interactions. Los Alamos has recently (January 1997) acquired a number of SGI/Cray Origin 2000 machines, each presently having 32 to 64 processors. These high performance computing systems are part of the Department of Energy`s Accelerated Strategic Computing Initiative (ASCI). While offering impressive performance now, upgrades to the system promise to deliver over 1 Teraflop (10(12) floating point operations per second) at peak performance before the turn of the century.

DOE Los Alamos National Laboratory – PV Feasibility Assessment, 2015 Update, NREL Final Report

Energy Technology Data Exchange (ETDEWEB)

Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Witt, Monica Rene [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-04-06

This report summarizes solar and wind potential for Los Alamos National Laboratory (LANL). This report is part of the “Los Alamos National Laboratory and Los Alamos County Renewable Generation” study.

Los Alamos Science, Number 25 -- 1997: Celebrating the neutrino

Energy Technology Data Exchange (ETDEWEB)

Cooper, N.G. [ed.

1997-12-31

This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos.

Los Alamos Science, Number 25 -- 1997: Celebrating the neutrino

International Nuclear Information System (INIS)

Cooper, N.G.

1997-01-01

This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos

Meson phase space density from interferometry

International Nuclear Information System (INIS)

Bertsch, G.F.

1993-01-01

The interferometric analysis of meson correlations a measure of the average phase space density of the mesons in the final state. The quantity is a useful indicator of the statistical properties of the systems, and it can be extracted with a minimum of model assumptions. Values obtained from recent measurements are consistent with the thermal value, but do not rule out superradiance effects

Vector mesons on the light front

International Nuclear Information System (INIS)

Naito, K.; Maedan, S.; Itakura, K.

2004-01-01

We apply the light-front quantization to the Nambu-Jona-Lasinio model with the vector interaction, and compute vector meson's mass and light-cone wavefunction in the large N limit. Following the same procedure as in the previous analyses for scalar and pseudo-scalar mesons, we derive the bound-state equations of a qq-bar system in the vector channel. We include the lowest order effects of the vector interaction. The resulting transverse and longitudinal components of the bound-state equation look different from each other. But eventually after imposing an appropriate cutoff, one finds these two are identical, giving the same mass and the same (spin-independent) light-cone wavefunction. Mass of the vector meson decreases as one increases the strength of the vector interaction

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

Energy Technology Data Exchange (ETDEWEB)

Bernardini, Alex Eduardo de

2001-07-01

Since the discovery of QCD (Quantum Chromodynamics), there have been remarkable technical achievements in perturbative calculations applied to hadrons. However, it is difficult to use QCD directly to compute hadronic properties. In this context, phenomenological potential models have provided extremely satisfactory results on description of ordinary hadrons, more specifically about quark-antiquark bound states (mesons). In this work we propose and study the main aspects in the construction of a potential model and search a generalized description of meson spectroscopy, with emphasis in heavy quark bound states. We analyze important aspects in the choice of the treatment in good agreement with the dynamics of interacting particles, attempting to relativistic aspects as well as to the possibilities of nonrelativistic approximation analysis. Initially the 'soft QCD' is employed to determine effective potential terms establishing the asymptotic Coulomb term from one gluon exchange approximation. At the same time, a linear confinement term is introduced in accordance with QCD and phenomenological prescription. We perform the calculations of mass spectroscopy for particular sets of mesons and we verify whether the potential model could be extended to calculating the electronic transition rate ({gamma}(q q-bar {yields} e{sup -}e{sup +})). Finishing, we discuss the real physical possibilities of development of a generalized potential model (all quark flavors), its possible advantages relative to experimental parametrization, complexity in numerical calculations and in the description of physical reality in agreement with a quantum field theory (QCD). (author)

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

Energy Technology Data Exchange (ETDEWEB)

Bernardini, Alex Eduardo de

2001-07-01

Since the discovery of QCD (Quantum Chromodynamics), there have been remarkable technical achievements in perturbative calculations applied to hadrons. However, it is difficult to use QCD directly to compute hadronic properties. In this context, phenomenological potential models have provided extremely satisfactory results on description of ordinary hadrons, more specifically about quark-antiquark bound states (mesons). In this work we propose and study the main aspects in the construction of a potential model and search a generalized description of meson spectroscopy, with emphasis in heavy quark bound states. We analyze important aspects in the choice of the treatment in good agreement with the dynamics of interacting particles, attempting to relativistic aspects as well as to the possibilities of nonrelativistic approximation analysis. Initially the 'soft QCD' is employed to determine effective potential terms establishing the asymptotic Coulomb term from one gluon exchange approximation. At the same time, a linear confinement term is introduced in accordance with QCD and phenomenological prescription. We perform the calculations of mass spectroscopy for particular sets of mesons and we verify whether the potential model could be extended to calculating the electronic transition rate ({gamma}(q q-bar {yields} e{sup -}e{sup +})). Finishing, we discuss the real physical possibilities of development of a generalized potential model (all quark flavors), its possible advantages relative to experimental parametrization, complexity in numerical calculations and in the description of physical reality in agreement with a quantum field theory (QCD). (author)

Composite vector mesons and string models

International Nuclear Information System (INIS)

Mandelstam, S.

1985-01-01

The author discusses the general question of gauge mesons in extended supergravities, and whether such theories can produce the gauge mesons corresponding to a group at least as large as SU(3) x SU(2) x U(1). An exciting conjecture in this direction was made a few years ago by previous authors, who suggested that there might be composite SU(8) gauge mesons in a supergravity model known as the N=8 model. Until we have a consistent, renormalizable theory of supergravity we cannot really obtain any indication of the truth or falseness of that conjecture. One form of the Neveu-Schwarz string model has been shown to be a theory of supergravity; it is finite at the one-loop level and probably in any order of perturbation theory. The discussion is within the framework of this model. The author questions whether massive vector mesons can possibly lose their mass due to interactions. Arguments have been given on both sides of this question, and the author believes that this can occur under certain circumstances. Our conclusions is that the FNNS mechanism will create a gauge symmetry in addition to the rigid symmetry

High statistics inclusive φ meson production at SPS energies

International Nuclear Information System (INIS)

Dijkstra, H.; Belau, E.

1986-01-01

Inclusive φ meson production has been measured for 100 GeV/c and 200 GeV/c incident π - , anti p and K - , and for 120 GeV/c and 200 GeV/c incident π + , p and K + , using a Be target. A total of 630,000 φ mesons has been recorded in the kinematic range 0 F F and dσ/dp T 2 . The longitudinal momentum distributions show that the strange valence quarks of the incident K mesons play an important role in φ meson production, even at small x F . The decay angular distribution of the φ meson is evaluated in the Gottfried-Jackson frame and is expressed in the elements of the density matrix. There is a small but significant cos 2 θ GJ dependence for small p T , which decreases for increasing p T . (Auth.)

Molecular components in P-wave charmed-strange mesons

CERN Document Server

Ortega, Pablo G.

2016-10-26

Results obtained by various experiments show that the $D_{s0}^{\\ast}(2317)$ and $D_{s1}(2460)$ mesons are very narrow states located below the $DK$ and $D^{\\ast}K$ thresholds, respectively. This is markedly in contrast with the expectations of naive quark models and heavy quark symmetry. Motivated by a recent lattice study which addresses the mass shifts of the $c\\bar{s}$ ground states with quantum numbers $J^{P}=0^{+}$ ($D_{s0}^{\\ast}(2317)$) and $J^{P}=1^{+}$ ($D_{s1}(2460)$) due to their coupling with $S$-wave $D^{(\\ast)}K$ thresholds, we perform a similar analysis within a nonrelativistic constituent quark model in which quark-antiquark and meson-meson degrees of freedom are incorporated. The quark model has been applied to a wide range of hadronic observables and thus the model parameters are completely constrained. The coupling between quark-antiquark and meson-meson Fock components is done using a modified version of the $^{3}P_{0}$ decay model. We observe that the coupling of the $0^{+}$ $(1^{+})$ mes...

Observation of an excited Bc+/- meson state with the ATLAS detector

Czech Academy of Sciences Publication Activity Database

Aad, G.; Abbott, B.; Abdallah, J.; Böhm, Jan; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav

2014-01-01

Roč. 113, č. 21 (2014), "2120041"-"212004-5" ISSN 0031-9007 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : error * statistical * p p * scattering * B/c+ * ATLAS * meson * mass difference * CERN LHC Coll * excited state * ground state * J/psi(3100) * pi+ pi- Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 7.512, year: 2014

CORNELL: CLEO discovers B meson penguins

International Nuclear Information System (INIS)

Anon.

1993-01-01

The CLEO collaboration at Cornell's CESR electron-positron storage ring has discovered a rare type of B meson decay in which only a high energy photon and a K* meson are produced. These decays provide the first unambiguous evidence for an alternative route for heavy quark decay that has been given the whimsical name ''penguin diagram''. In the mid-1970s penguin diagrams were proposed to explain the puzzling strangeness quantum number selection rules in the decay of K mesons. At the same time it was realized that penguin diagrams could also be important in the CP violation seen in neutral K meson decay. CP violation, an asymmetry between matter and antimatter, is an essential ingredient in understanding why there is much more matter than antimatter in the universe. CP violation introduces a definite direction to the arrow of time, which could otherwise point equally forwards or backwards. In addition, penguin decays are very sensitive to some extensions of the Standard Model of weak decay. Although penguin diagrams were first proposed to explain an effect in K meson decay, the K system gives no unique signature for them, and verification of penguin processes meant looking elsewhere. In the Standard Model, quarks decay under the influence of the weak force, emitting a W boson. Since the W is charged, the charge of the initial quark differs from that of the final quark, so the charge of the quark changes as well as its flavour

Quark-gluon mixing in scalar mesons

International Nuclear Information System (INIS)

Eremyan, Sh.S.; Nazaryan, A.E.

1986-01-01

Scalar mesons are considered within the quark-gluon mixing model. It is shown that there exists decouplet of scalar particles consisting of S* (975), ε (1400), S*' (1700), δ (980) and κ (1350) resonances. It has turned out that the long ago known S* (975)-resonance is a nearly pure glouball. A good description of all available experimental data on scalar meson decays is obtained

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.

SU(4) flavor symmetry breaking in D-meson couplings to light hadrons

Energy Technology Data Exchange (ETDEWEB)

Fontoura, C.E. [Instituto Tecnologico da Aeronautica, DCTA, Sao Jose dos Campos, SP (Brazil); Universidade Estadual Paulista, Instituto de Fisica Teorica, Sao Paulo, SP (Brazil); Haidenbauer, J. [Institute for Advanced Simulation, Institut fuer Kernphysik, and Juelich Center for Hadron Physics, Forschungszentrum Juelich, Juelich (Germany); Krein, G. [Universidade Estadual Paulista, Instituto de Fisica Teorica, Sao Paulo, SP (Brazil)

2017-05-15

The validity of SU(4)-flavor symmetry relations of couplings of charmed D-mesons to light mesons and baryons is examined with the use of {sup 3}P{sub 0} quark-pair creation model and nonrelativistic quark-model wave functions. We focus on the three-meson couplings ππρ, KKρ and DDρ and baryon-baryon-meson couplings NNπ, NΛK and NΛ{sub c}D. It is found that SU(4)-flavor symmetry is broken at the level of 30% in the DDρ tree-meson couplings and 20% in the baryon-baryon-meson couplings. Consequences of these findings for DN cross sections and existence of bound states D-mesons in nuclei are discussed. (orig.)

Study of light mesons with WASA-at-COSY

Science.gov (United States)

Prencipe, Elisabetta

2014-06-01

The WASA detector, operating at the COSY facility in Jülich (Germany) has been collecting data since 2007. The experiment allows to perform studies of light mesons, such as π0, η and ω rare decay processes, in order to perform precise measurements of branching ratios, determine Dalitz plot parameters, test symmetry and symmetry breaking, and evaluate transition form factors. In the experiments a proton or deuteron beam impinged on a pellet target of hydrogen or deuterium, which allows the reactions proton-proton (pp) or proton-deuteron (pd). A high-statistics sample of η mesons has been collected: in the reaction pd →3He η, 3×107η mesons were tagged at a beam energy of 1.0 GeV, while 5×108η mesons were produced in the reaction pp → ppη at 1.4 GeV. This corresponds to the production of 10 η/s and 100 η/s, respectively, for the two reaction processes. In the pp dataset a higher background level is found compared to the pd data set. In both cases, we identify the η mesons by means of the missing mass derived from the recoil particles. A kinematic fit largely rejects the background in our analysis. The advantage in using the pp dataset is that the production of η mesons is almost a factor of 10 higher than in the pd fusion to 3He. As we plan to measure the branching ratios of very rare processes, high statistics is needed. A summary of the recent activity on the study of light mesons with WASA-at-COSY here is given.

Study of light mesons with WASA-at-COSY

Directory of Open Access Journals (Sweden)

Prencipe Elisabetta

2014-06-01

Full Text Available The WASA detector, operating at the COSY facility in Jülich (Germany has been collecting data since 2007. The experiment allows to perform studies of light mesons, such as π0, η and ω rare decay processes, in order to perform precise measurements of branching ratios, determine Dalitz plot parameters, test symmetry and symmetry breaking, and evaluate transition form factors. In the experiments a proton or deuteron beam impinged on a pellet target of hydrogen or deuterium, which allows the reactions proton-proton (pp or proton-deuteron (pd. A high-statistics sample of η mesons has been collected: in the reaction pd →3He η, 3×107η mesons were tagged at a beam energy of 1.0 GeV, while 5×108η mesons were produced in the reaction pp → ppη at 1.4 GeV. This corresponds to the production of 10 η/s and 100 η/s, respectively, for the two reaction processes. In the pp dataset a higher background level is found compared to the pd data set. In both cases, we identify the η mesons by means of the missing mass derived from the recoil particles. A kinematic fit largely rejects the background in our analysis. The advantage in using the pp dataset is that the production of η mesons is almost a factor of 10 higher than in the pd fusion to 3He. As we plan to measure the branching ratios of very rare processes, high statistics is needed. A summary of the recent activity on the study of light mesons with WASA-at-COSY here is given.

Computing K and D meson masses with Nf=2+1+1 twisted mass lattice QCD

International Nuclear Information System (INIS)

Baron, Remi; Blossier, Benoit; Boucaud, Philippe

2010-05-01

We discuss the computation of the mass of the K and D mesons within the framework of N f =2+1+1 twisted mass lattice QCD from a technical point of view. These quantities are essential, already at the level of generating gauge configurations, being obvious candidates to tune the strange and charm quark masses to their physical values. In particular, we address the problems related to the twisted mass flavor and parity symmetry breaking, which arise when considering a non-degenerate (c,s) doublet. We propose and verify the consistency of three methods to extract the K and D meson masses in this framework. (orig.)

Renormalization group analysis of B →π form factors with B -meson light-cone sum rules

Science.gov (United States)

Shen, Yue-Long; Wei, Yan-Bing; Lü, Cai-Dian

2018-03-01

Within the framework of the B -meson light-cone sum rules, we review the calculation of radiative corrections to the three B →π transition form factors at leading power in Λ /mb. To resum large logarithmic terms, we perform the complete renormalization group evolution of the correlation function. We employ the integral transformation which diagonalizes evolution equations of the jet function and the B -meson light-cone distribution amplitude to solve these evolution equations and obtain renormalization group improved sum rules for the B →π form factors. Results of the form factors are extrapolated to the whole physical q2 region and are compared with that of other approaches. The effect of B -meson three-particle light-cone distribution amplitudes, which will contribute to the form factors at next-to-leading power in Λ /mb at tree level, is not considered in this paper.

The search for scalar mesons

International Nuclear Information System (INIS)

Pennington, M.R.

1988-09-01

The search of I = 0 0 ++ mesons is described. We highlight the crucial role played by the states in the 1 GeV region. An analysis program that with unimpeachable data would produce definitive results on these is outlined and shown with present data to provide prima facie evidence for dynamics beyond that of the quark model. We briefly speculate on the current status of the lowest mass scalar mesons and discuss how experiment can resolve the unanswered issues. 30 refs., 6 figs., 1 tab

Proceedings of the conference on numerical methods in high temperature physics

International Nuclear Information System (INIS)

Alcouffe, R.E.; Holm, D.D.; O'Rourke, P.J.

1988-11-01

These proceedings contain full papers presented at the Los Alamos Conference on High Temperature Physics. This conference discussed many aspects of high temperature physics including hydrodynamics, radiation and particle transport and some computational issues important for efficient calculations. The meetings was held between researchers from Los Alamos and the French Commissariat a L'Energy Atomique

Elements of beauty physics

International Nuclear Information System (INIS)

Morenas, Vincent

2006-01-01

The physics of B is an important side of the particle physics both from theoretical and experimental point of view. This dissertation addresses a number of aspects of this subject among which at first there are certain usual theoretical hypotheses: - the duality hypothesis which assumes that most of the inclusive calculations of the transitions between hadron states implies implicitly processes described only by transitions of quarks constituents of the respective hadrons. This hypothesis was tested for the case of semileptonic decays of B mesons and causes of possible violations were investigated; the factorization hypothesis, a simplifying assumption, currently used in the field, allows for instance the study of the B mesons decay into other two mesons. We have carried out an exhaustive study of the available experimental data as compared with an improved version of this hypothesis. Further, we present a problem related to the production of states of l=1 orbital angular momentum in B mesons decays: the experimental data go against all the phenomenological theoretical models. Thus we propose a tentative solution of the puzzle using the lattice QCD. Finally we describe the APEnext project (the European parallel computer project dedicated to lattice calculations)

Meson spectral functions at finite temperature

International Nuclear Information System (INIS)

Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S.

2001-10-01

The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T c . The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64) 3 x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature. (orig.)

Meson spectral functions at finite temperature

International Nuclear Information System (INIS)

Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S.

2002-01-01

The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T c . The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64) 3 x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature

Meson spectral functions at finite temperature

Energy Technology Data Exchange (ETDEWEB)

Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S

2002-03-01

The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T{sub c}. The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64){sup 3} x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature.

Meson spectral functions at finite temperature

Energy Technology Data Exchange (ETDEWEB)

Wetzorke, I.; Karsch, F.; Laermann, E.; Petreczky, P.; Stickan, S. [Bielefeld Univ. (Germany). Fakultaet fuer Physik

2001-10-01

The Maximum Entropy Method provides a Bayesian approach to reconstruct the spectral functions from discrete points in Euclidean time. The applicability of the approach at finite temperature is probed with the thermal meson correlation function. Furthermore the influence of fuzzing/smearing techniques on the spectral shape is investigated. We present first results for meson spectral functions at several temperatures below and above T{sub c}. The correlation functions were obtained from quenched calculations with Clover fermions on large isotropic lattices of the size (24 - 64){sup 3} x 16. We compare the resulting pole masses with the ones obtained from standard 2-exponential fits of spatial and temporal correlation functions at finite temperature and in the vacuum. The deviation of the meson spectral functions from free spectral functions is examined above the critical temperature. (orig.)

A unified model of K- and π-mesons

International Nuclear Information System (INIS)

Skyrme, T.H.R.

1994-01-01

On the foundation of an antecedent non-linear meson field theory it is suggested that the π-meson field may be described in terms of collective motions of the K-meson fields. A particular model of the K-nucleon interaction is considered whose collective π-modes have symmetrical PV coupling with the nucleon system; parity is conserved to a great extent for the π-nucleon system in the absence of strange particles. The direct K-nucleon interactions do not conserve parity; their sign and symmetry are qualitatively acceptable. The masses and coupling constants of the meson fields are determinate in terms of one universal coupling constant and a cut-off. The structure of this model suggests a natural way for the introduction of the 'spurion', describing weak interactions that violate strangeness. (author). 6 refs

Measurement of elastic electroproduction of $\\phi$ mesons at HERA

CERN Document Server

Adloff, C.; Andrieu, B.; Arkadov, V.; Astvatsatourov, A.; Ayyaz, I.; Babaev, A.; Bahr, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bassler, U.; Bate, P.; Beglarian, A.; Behnke, O.; Beier, C.; Belousov, A.; Benisch, T.; Berger, Christoph; Bernardi, G.; Berndt, T.; Bizot, J.C.; Borras, K.; Boudry, V.; Braunschweig, W.; Brisson, V.; Broker, H.B.; Brown, D.P.; Bruckner, W.; Bruel, P.; Bruncko, D.; Burger, J.; Busser, F.W.; Bunyatyan, A.; Burkhardt, H.; Burrage, A.; Buschhorn, G.; Campbell, A.J.; Cao, Jun; Carli, T.; Caron, S.; Chabert, E.; Clarke, D.; Clerbaux, B.; Collard, C.; Contreras, J.G.; Coughlan, J.A.; Cousinou, M.C.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; David, M.; Davidsson, M.; Delcourt, B.; Delerue, N.; Demirchyan, R.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dixon, P.; Dodonov, V.; Dowell, J.D.; Droutskoi, A.; Duprel, C.; Eckerlin, Guenter; Eckstein, D.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellerbrock, M.; Elsen, E.; Erdmann, M.; Erdmann, W.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Ferron, S.; Fleischer, M.; Flugge, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Foster, J.M.; Franke, G.; Gabathuler, E.; Gabathuler, K.; Garvey, J.; Gassner, J.; Gayler, Joerg; Gerhards, R.; Ghazarian, S.; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goodwin, C.; Grab, C.; Grassler, H.; Greenshaw, T.; Grindhammer, Guenter; Hadig, T.; Haidt, D.; Hajduk, L.; Haynes, W.J.; Heinemann, B.; Heinzelmann, G.; Henderson, R.C.W.; Hengstmann, S.; Henschel, H.; Heremans, R.; Herrera, G.; Herynek, I.; Hilgers, M.; Hiller, K.H.; Hladky, J.; Hoting, P.; Hoffmann, D.; Hoprich, W.; Horisberger, R.; Hurling, S.; Ibbotson, M.; Issever, C.; Jacquet, M.; Jaffre, M.; Janauschek, L.; Jansen, D.M.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jones, M.A.S.; Jung, H.; Kastli, H.K.; Kant, D.; Kapichine, M.; Karlsson, M.; Karschnick, O.; Kaufmann, O.; Kausch, M.; Keil, F.; Keller, N.; Kennedy, J.; Kenyon, I.R.; Kermiche, S.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Knies, G.; Koblitz, B.; Kolya, S.D.; Korbel, V.; Kostka, P.; Kotelnikov, S.K.; Krasny, M.W.; Krehbiel, H.; Kroseberg, J.; Krucker, D.; Kruger, K.; Kupper, A.; Kuhr, T.; Kurca, T.; Kutuev, R.; Lachnit, W.; Lahmann, R.; Lamb, D.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Lebedev, A.; Leissner, B.; Lemrani, R.; Lendermann, V.; Levonian, S.; Lindstrom, M.; Lobodzinska, E.; Lobodzinski, B.; Loktionova, N.; Lubimov, V.; Luders, S.; Luke, D.; Lytkin, L.; Magnussen, N.; Mahlke-Kruger, H.; Malden, N.; Malinovski, E.; Malinovski, I.; Maracek, R.; Marage, P.; Marks, J.; Marshall, R.; Martyn, H.U.; Martyniak, J.; Maxfield, S.J.; Mehta, A.; Meier, K.; Merkel, P.; Metlica, F.; Meyer, H.; Meyer, J.; Meyer, P.O.; Mikocki, S.; Milstead, D.; Mkrtchyan, T.; Mohr, R.; Mohrdieck, S.; Mondragon, M.N.; Moreau, F.; Morozov, A.; Morris, J.V.; Muller, K.; Murin, P.; Nagovizin, V.; Naroska, B.; Naumann, J.; Naumann, T.; Nellen, G.; Newman, Paul R.; Nicholls, T.C.; Niebergall, F.; Niebuhr, C.; Nix, O.; Nowak, G.; Nunnemann, T.; Olsson, J.E.; Ozerov, D.; Panassik, V.; Pascaud, C.; Patel, G.D.; Perez, E.; Phillips, J.P.; Pitzl, D.; Poschl, R.; Potachnikova, I.; Povh, B.; Rabbertz, K.; Radel, G.; Rauschenberger, J.; Reimer, P.; Reisert, B.; Reyna, D.; Riess, S.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Royon, C.; Rusakov, S.; Rybicki, K.; Sankey, D.P.C.; Scheins, J.; Schilling, F.P.; Schleper, P.; Schmidt, D.; Schoeffel, L.; Schoning, A.; Schorner, T.; Schroder, V.; Schultz-Coulon, H.C.; Sedlak, K.; Sefkow, F.; Chekelian, V.I.; Sheviakov, I.; Shtarkov, L.N.; Siegmon, G.; Sievers, P.; Sirois, Y.; Sloan, T.; Smirnov, P.; Solochenko, V.; Solovev, Y.; Spaskov, V.; Specka, Arnd E.; Spitzer, H.; Stamen, R.; Steinhart, J.; Stella, B.; Stellberger, A.; Stiewe, J.; Straumann, U.; Struczinski, W.; Swart, M.; Tasevsky, M.; Tchernyshov, V.; Tchetchelnitski, S.; Thompson, Graham; Thompson, P.D.; Tobien, N.; Traynor, D.; Truoel, Peter; Tsipolitis, G.; Turnau, J.; Turney, J.E.; Tzamariudaki, E.; Udluft, S.; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vazdik, Y.; von Dombrowski, S.; Wacker, K.; Wallny, R.; Walter, T.; Waugh, B.; Weber, G.; Weber, M.; Wegener, D.; Wegner, A.; Wengler, T.; Werner, M.; White, G.; Wiesand, S.; Wilksen, T.; Winde, M.; Winter, G.G.; Wissing, C.; Wobisch, M.; Wollatz, H.; Wunsch, E.; Wyatt, A.C.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zomer, F.; Zsembery, J.

2000-01-01

The elastic electroproduction of phi mesons is studied at HERA with the H1 detector for photon virtualities 1 < Q^2 < 15 GeV^2 and hadronic centre of mass energies 40 < W < 130 GeV. The Q^2 and t dependences of the cross section are extracted (t being the square of the four-momentum transfer to the target proton). When plotted as function of (Q^2 + M_V^2) and scaled by the appropriate SU(5) quark charge factor, the phi meson cross section agrees within errors with the cross sections of the vector mesons V = rho, omega and J/psi. A detailed analysis is performed of the phi meson polarisation state and the ratio of the production cross sections for longitudinally and transversely polarised phi mesons is determined. A small but significant violation of s-channel helicity conservation (SCHC) is observed.

Photoproduction of scalar mesons at medium energies

Energy Technology Data Exchange (ETDEWEB)

Da Silva, M. L. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-090, Pelotas, RS (Brazil); Machado, M. V. [High Energy Physics Phenomenology Group, GFPAE IF-UFRGS, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

2013-03-25

In this work we will focus on photoproduction of mesons states a{sub 0}(980), f{sub 0}(1500) and f{sub 0}(1710). The f{sub 0}(1500) and f{sub 0}(1710) mesons will be considered in distinct mixing possibilities and assuming that a{sub 0}(980) is member of the ground-state nonet. The theoretical formalism is the Regge approach with reggeized {rho} and {omega} exchange. The differential and integrated total cross section are computed for the cases of the mesons a{sub 0}(980), f{sub 0}(1500) and f{sub 0}(1710) focusing the GlueX energy regime with photon energy E = 9 GeV.

Semileptonic B-meson decays in SU(3)

International Nuclear Information System (INIS)

Li Zuohong; Hou Yunzhi

1994-01-01

Based on the SU(3) approximate symmetry in the strong interaction three-body and four-body semileptonic B-meson decays are analyzed. Relations between decay rates are derived. Some of these relations may provide information on the nature of various competing dynamical effects that can occur in semileptonic B-meson decays

A survey of macromycete diversity at Los Alamos National Laboratory, Bandelier National Monument, and Los Alamos County; A preliminary report

Energy Technology Data Exchange (ETDEWEB)

Jarmie, N.; Rogers, F.J. [Mycology Associates, Los Alamos, NM (United States)

1997-11-01

The authors have completed a 5-year survey (1991--1995) of macromycetes found in Los Alamos County, Los Alamos National Laboratory, and Bandelier National Monument. The authors have compiled a database of 1,048 collections, their characteristics, and identifications. The database represents 123 (98%) genera and 175 (73%) species reliably identified. Issues of habitat loss, species extinction, and ecological relationships are addressed, and comparisons with other surveys are made. With this baseline information and modeling of this baseline data, one can begin to understand more about the fungal flora of the area.

Decays of mesons with charm quarks on the lattice

International Nuclear Information System (INIS)

Ali Khan, A.; Braun, V.; Burch, T.; Goeckeler, M.; Schaefer, A.; Schierholz, G.

2007-10-01

We investigate mesons containing charm quarks on fine lattices with a -1 ∝ 5 GeV. The quenched approximation is employed using theWilson gauge action at β = 6.6 and nonperturbatively O(a) improvedWilson quarks. We present results for decay constants using various interpolating fields and give preliminary results for form factors of semileptonic decays of D s mesons to light pseudoscalar mesons. (orig.)

Electroproduction of pseudoscalar mesons at large transverse momenta

Energy Technology Data Exchange (ETDEWEB)

Domokos, G.; Kovesi-Domokos, S.; Yunn, B. C.

1973-07-15

Inclusive electroproduction of spinless (pseudoscalar) mesons at large transverse momenta is studied in the framework of local scale invariance. Scaling laws are established for the structure iunctions and approximate analytic expressions are derived for the scaling functions. It is predicted that the cross section decreases essentially according to a power law as a function of the transverse momentum of the observed meson, similarly to hadronic cross sections. The production rate of heavy mesons is found to rise slowly with the laboratory energy of the virtual photon. (auth)

Meson-mass generation by instantons, 2

Energy Technology Data Exchange (ETDEWEB)

Saito, T [Kyoto Prefectural Univ. of Medicine (Japan); Shigemoto, K

1979-05-01

In a previous work we discussed how pseudo-scalar mesons and scalar mesons acquire their masses by instantons in the colored gauge field. We considered there the two-flavor model with chiral U(2) x U(2) symmetry. In the present paper the same problem is discussed, including the chiral flavor U(3) x U(3) symmetry. An importance of non-local effects due to instantons is emphasized.

The interpretation of the iota meson

International Nuclear Information System (INIS)

Frank, M.

1985-01-01

The authors analyze the iota (1440) meson in a non-relativistic quark model. The authors review the experimental data, then attempt to incorporate it in the mass spectrum and radiative decays of the low-lying pseudoscalar and vector mesons. Correlating these results with production decay rates from J/psi and the radiative decays of iota, the authors conclude that the iota has to be interpreted as having a strong gluonium component

Excited charmed mesons

International Nuclear Information System (INIS)

Butler, J.N.; Shukla, S.

1995-05-01

The experimental status of excited charmed mesons is reviewed and is compared to theoretical expectations. Six states have been observed and their properties are consistent with those predicted for excited charmed states with orbital angular momentum equal to one

Proceedings of the conference on numerical methods in high temperature physics

Energy Technology Data Exchange (ETDEWEB)

Alcouffe, R.E.; Holm, D.D.; O' Rourke, P.J. (comps.)

1988-11-01

These proceedings contain full papers presented at the Los Alamos Conference on High Temperature Physics. This conference discussed many aspects of high temperature physics including hydrodynamics, radiation and particle transport and some computational issues important for efficient calculations. The meetings was held between researchers from Los Alamos and the French Commissariat a L'Energy Atomique (CEA).

Report of the Los Alamos accelerator automation application toolkit workshop

International Nuclear Information System (INIS)

Clout, P.; Daneels, A.

1990-01-01

A 5 day workshop was held in November 1988 at Los Alamos National Laboratory to address the viability of providing a toolkit optimized for building accelerator control systems. The workshop arose from work started independently at Los Alamos and CERN. This paper presents the discussion and the results of the meeting. (orig.)

Notes on Los Alamos

Energy Technology Data Exchange (ETDEWEB)

Meade, Roger Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-04-05

In 1954 an unknown author drafted a report, reprinted below, describing the Laboratory and the community as they existed in late 1953. This report, perhaps intended to be crafted into a public relations document, is valuable because it gives us an autobiographical look at Los Alamos during the first half of the 1950s. It has been edited to enhance readability.

New searches for the C-noninvariant decay π0→3γ and the rare decay π0→4γ

International Nuclear Information System (INIS)

McDonough, J.; Highland, V.L.; McFarlane, W.K.

1988-01-01

A search for the charge-conjugation-noninvariant decay π 0 →3γ has been made using the Crystal Box of the Los Alamos Meson Physics Facility. No signal in excess of background was observed, resulting in a branching-ratio upper limit of 3.1 x 10/sup -8/ (90% C.L.). A new upper limit of 2 x 10/sup -8/ (90% C.L.) was also established for the allowed decay π 0 →4γ

Characteristics of a delay-line readout in a cylindrical drift chamber system

International Nuclear Information System (INIS)

Barber, R.; Ahmed, M.W.; Dzemidzic, M.; Empl, A.; Hungerford, E.V.; Lan, K.J.; Wilson, J.; Cooper, M.D.; Gagliardi, C.A.; Haim, D.; Kim, G.J.; Koetke, D.D.; Tribble, R.E.; Van Ausdeln, L.A.

2002-01-01

This paper reports on the design, construction, and operational characteristics of a delay-line readout implemented on the cathode foils of a cylindrical drift chamber system. The readout was used to determine the position of an event along the length of the 1.74 m drift wires in the MEGA detectors used at the Los Alamos Meson Physics Facility. The performance of the system is interpreted by comparison to a PSPICE simulation, and to simple analytical models

Measurement of observables in the pion-nucleon system and investigation of charge symmetry in 3He and 3H. Progress report, March 1, 1985-February 28, 1986

International Nuclear Information System (INIS)

Sadler, M.E.

1986-03-01

Progress is reported for the past year in pion scattering programs. The measurements include: (1) a complete set of observables in the pion-nucleon system in the momentum interval 400 to 700 MeV/c, (2) differential cross sections at low energy for pion-nucleon charge exchange, and (3) elastic and inelastic scattering of π +- on 3 H and 3 He. The experiments are conducted at the Clinton P. Anderson Meson Physics Facility at Los Alamos (LAMPF)

A unitarized meson model including color Coulomb interaction

International Nuclear Information System (INIS)

Metzger, Kees.

1990-01-01

Ch. 1 gives a general introduction into the problem field of the thesis. It discusses in how far the internal structure of mesons is understood theoretically and which models exist. It discusses from a phenomenological point of view the problem of confinement indicates how quark models of mesons may provide insight in this phenomenon. In ch. 2 the formal theory of scattering in a system with confinement is given. It is shown how a coupled channel (CC) description and the work of other authors fit into this general framework. Explicit examples and arguments are given to support the CC treatment of such a system. In ch. 3 the full coupled-channel model as is employed in this thesis is presented. On the basis of arguments from the former chapters and the observed regularities in the experimental data, the choices underlying the model are supported. In this model confinement is described with a mass-dependent harmonic-oscillator potential and the presence of open (meson-meson) channels plays an essential role. In ch. 4 the unitarized model is applied to light scalar meson resonances. In this regime the contribution of the open channels is considerable. It is demonstrated that the model parameters as used for the description of the pseudo-scalar and vector mesons, unchanged can be used for the description of these mesons. Ch. 5 treats the color-Coulomb interaction. There the effect of the Coulomb interaction is studied in simple models without decay. The results of incorporating the color-Coulomb interaction into the full CC model are given in ch.6. Ch. 7 discusses the results of the previous chapters and the present status of the model. (author). 182 refs.; 16 figs.; 33 tabs

J/Ψ decays, quark-gluon mixing in light mesons and glueball interpretation of L(1440), Θ(1720) and S*(980)-mesons

International Nuclear Information System (INIS)

Eremyan, Sh.S.; Nazaryan, A.Eh.

1987-01-01

The mixing angles for pseudoscalar, tensor and scalar meson multiplets are obtained in assumption on existence of a glueball component. The results are shown to be independent on the kind of the mixing matrix. It turned out that L(1440), Θ(1720) and S*(980) mesons are quite real candidates for glueballs. All the available experimental data on two-particle decays of 0 - , 2 + and 0 + -mesons are described and predictions for a large of such decays are given. 13 refs.; 6 figs.; 9 tabs

Pre Incident Planning For The Los Alamos National Laboratory

Science.gov (United States)

2017-12-01

laboratory was asked to design and build the world’s first atomic bomb . The Los Alamos Fire Department (LAFD) provides emergency response services to...Project: the newly established laboratory was asked to design and build the world’s first atomic bomb . The Los Alamos Fire Department (LAFD) provides...lower priority despite its importance to the responders’ scene safety.20 In a Carolina Fire Rescue EMS Journal article, retired New York City

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...

Azimuthal anisotropy of D -meson production in Pb-Pb collisions at sNN =2.76 TeV

Czech Academy of Sciences Publication Activity Database

Abelev, B.; Adam, J.; Adamová, Dagmar; Bielčík, J.; Bielčíková, Jana; Brož, M.; Čepila, J.; Ferencei, Jozef; Hladký, Jan; Křelina, M.; Křížek, Filip; Kučera, Vít; Kushpil, Svetlana; Mareš, Jiří A.; Pachr, M.; Petráček, V.; Petráň, M.; Schulc, M.; Špaček, M.; Šumbera, Michal; Vajzer, Michal; Wagner, V.; Zach, Č.; Závada, Petr

2014-01-01

Roč. 90, č. 3 (2014), s. 034904 ISSN 0556-2813 R&D Projects: GA MŠk(CZ) LG13031 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : ALICE collaboration * heavy ion collisions * meson production Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders; BF - Elementary Particles and High Energy Physics (FZU-D) Impact factor: 3.733, year: 2014

Environmental surveillance at Los Alamos during 1976

International Nuclear Information System (INIS)

1977-04-01

This report documents the environmental monitoring program at the Los Alamos Scientific Laboratory (LASL) in 1976. Data are presented for concentrations of radioactivity measured in air, ground and surface waters, sediments, soils, and foodstuffs, and are compared with relevant U.S. Energy Research and Development Administration guides and/or data from other reporting periods. Levels of external penetrating radiation measured in the LASL environs are given. The average whole-body radiation dose to residents of Los Alamos County resulting from LASL operations is calculated. Chemical qualities of surface and ground waters in the LASL environs have been determined and compared to applicable standards. Results of related environmental studies are summarized

Environmental surveillance at Los Alamos during 1974

International Nuclear Information System (INIS)

Apt, K.E.; Lee, V.J.

1975-05-01

The CY 1974 environmental monitoring program of the Los Alamos Scientific Laboratory (LASL) is documented. Data are presented for concentrations of radioactivity measured in air, ground, and surface waters, sediments, and soils, and those data are compared with relevant AEC guides and/or data from other reporting periods. Levels of external penetrating radiation measured in the LASL environs are given. The average whole-body radiation dose to residents of Los Alamos County resulting from LASL operations is calculated. Chemical and biological qualities of surface and ground waters of the LASL environs have been determined and are compared to applicable standards. Results of related environmental studies are provided. (U.S.)

Environmental surveillance at Los Alamos during 1975

International Nuclear Information System (INIS)

Apt, K.E.; Lee, V.J.

1976-04-01

This report documents the CY 1975 environmental monitoring program of the Los Alamos Scientific Laboratory (LASL). Data are presented for concentrations of radioactivity measured in air, ground and surface waters, sediments, soils, and foodstuffs, and are compared with relevant U.S. Energy Research and Development Administration guides and/or data from other reporting periods. Levels of external penetrating radiation measured in the LASL environs are given. The average whole-body radiation dose to residents of Los Alamos County resulting from LASL operations is calculated. Chemical qualities of surface and ground waters in the LASL environs have been determined and compared to applicable standards. Results of related environmental studies are summarized

On the Reduction of Vector and Axial-Vector Fields in a Meson Effective Action at O(p4)

International Nuclear Information System (INIS)

Bel'kov, A.A.; Lanev, A.V.; Schaale, A.

1994-01-01

Starting from an effective NJL-type quark interaction we have derived an effective meson action for the pseudoscalar sector. The vector and axial-vector degrees of freedom have been integrated out, applying the static equations of motion. As the results we have found a (reduced) pseudoscalar meson Lagrangian of the Gasser-Leutwyler type with modified structure coefficients L i . This method has been also used to construct the reduced weak and electromagnetic-weak currents. The application of the reduced Lagrangian and currents has been considered in physical processes. 36 refs., 1 fig., 1 tab

Nuclear science research at the WNR and LANSCE neutron sources

International Nuclear Information System (INIS)

Lisowski, P.W.

1994-01-01

The Weapons Neutron Research (WNR) Facility and the Los Alamos Neutron Scattering Center (LANSCE) use 800 MeV proton beam from the Los Alamos Meson Physics Facility (LAMPF) to generate intense bursts of neutrons. Experiments using time-of-flight (TOF) energy determination can cover an energy range from thermal to about 2 MeV at LANSCE and 0.1 to 800 MeV at WNR. At present, three flight paths at LANSCE and six flight paths at WNR are used in basic and applied nuclear science research. In this paper we present a status report on WNR and LANSCE, discuss plans for the future, and describe three experiments recently completed or underway that use the unique features of these sources

UCLA intermediate energy nuclear physics and relativistic heavy ion physics. Annual report, February 1, 1983-January 31, 1984

International Nuclear Information System (INIS)

1984-01-01

In this contract year the UCLA Intermediate Energy Group has continued to pursue a general set of problems in intermediate energy physics using new research tools and theoretical insights. Our program to study N-N scattering and proton-light nucleus scattering has been enhanced by a new polarized target facility (both hydrogen and deuterium) at the High Resolution Spectrometer (HRS) of the Los Alamos Meson Physics Facility (LAMPF). This facility has been constructed by our group in collaboration with physicists from KEK, LAMPF and the University of Minnesota; and the first set of experiments studying polarized beam-polarized target scattering at the HRS were completed this summer and early fall. The HRS mode of operation has led to some unique design features which are described. At the Bevalac, a new beam line spectrometer will be constructed for us during this year and next to significantly enhance our capability to study subthreshold k + , k - and anti p production in relativistic heavy ion collisions and to search for fractionally charged particles. During this period a proposal is being prepared for a very large acceptance spectrometer and its associated beam line which will be used to detect dilepton pairs produced in relativistic heavy ion collisions. In concert with these experimental projects, theoretical advances in the understanding of new data from the HRS, particularly spin transfer data, have been made by the UCLA group and are described

Self-consistent descriptions of vector mesons in hot matter reexamined

International Nuclear Information System (INIS)

Riek, Felix; Knoll, Joern

2010-01-01

Technical concepts are presented that improve the self-consistent treatment of vector mesons in a hot and dense medium. First applications concern an interacting gas of pions and ρ mesons. As an extension of earlier studies, we thereby include random-phase-approximation-type vertex corrections and further use dispersion relations to calculate the real part of the vector-meson self-energy. An improved projection method preserves the four transversality of the vector-meson polarization tensor throughout the self-consistent calculations, thereby keeping the scheme void of kinematical singularities.

Experimental evidence for hadroproduction of exotic mesons

International Nuclear Information System (INIS)

G. S. Adams; T. Adams; Z. Bar-Yam; J. M. Bishop; V. A. Bodyagin; B. B. Brabson; D. S. Brown; N. M. Cason; S. U. Chung; R. R. Crittenden; J. P. Cummings; K. Danyo; S. Denisov; V. Dorofeev; J. P. Dowd; A. R. Dzierba; P. Eugenio; J. Gunter; R. W. Hackenburg; M. Hayek; E. I. Ivanov; I. Kachaev; W. Kern; E. King; O. L. Kodolova; V. L. Korotkikh; M. A. Kostin; J. Kuhn; R. Lindenbusch; V. Lipaev; J. M. LoSecco; J. J. Manak; J. Napolitano; M. Nozar; C. Olchanski; A. I. Ostrovidov; T. K. Pedlar; A. Popov; D. R. Rust; D. Ryabchikov; A. H. Sanjari; L. I. Sarycheva; E. Scott; K. K. Seth; N. Shenhav; W. D. Shephard; N. B. Sinev; J. A. Smith; P. T. Smith; D. L. Stienike; T. Sulanke; S. A. Taegar; S. Teige; D. R. Thompson; I. N. Vardanyan; D. P. Weygand; D. White; H. J. Willutzki; J. Wise; M. Witkowski; A. A. Yershov; D. Zhao

2001-01-01

New measurements of peripheral meson production are presented. The data confirm the existence of exotic mesons at 1.4 and 1.6 GeV/c2. The latter state dominates the eta'pi- decay spectrum. The data on eta pi+pi-pi- decay show large strength in several exotic (Jpc = 1- +) waves as well

Exclusive ρ.sup.0./sup. meson photoproduction with a leading neutron at HERA

Czech Academy of Sciences Publication Activity Database

Andreev, V.; Baghdasaryan, A.; Begzsuren, K.; Cvach, Jaroslav; Hladký, Jan; Reimer, Petr

2016-01-01

Roč. 76, č. 1 (2016), 1-21, č. článku 41. ISSN 1434-6044 R&D Projects: GA MŠk LG14033 Institutional support: RVO:68378271 Keywords : deep-inelastic scattering * vector meson production * pion exchange model * elastic photoproduction Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.331, year: 2016

QED effects in the pseudoscalar meson sector

Energy Technology Data Exchange (ETDEWEB)

Horsley, R. [School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD (United Kingdom); Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe, Hyogo, 650-0047 (Japan); Perlt, H. [Institut für Theoretische Physik, Universität Leipzig, Brüderstrasse 16, Leipzig, 04109 (Germany); Pleiter, D. [Jülich Supercomputer Centre, Forschungszentrum Jülich, Jülich, 52425 (Germany); Institut für Theoretische Physik, Universität Regensburg, Regensburg, 93040 (Germany); Rakow, P.E.L. [Theoretical Physics Division, Department of Mathematical Sciences, University of Liverpool, Peach Street , Liverpool, L69 3BX (United Kingdom); Schierholz, G. [Deutsches Elektronen-Synchrotron DESY, Hamburg, 22603 (Germany); Schiller, A. [Institut für Theoretische Physik, Universität Leipzig, Brüderstrasse 16, Leipzig, 04109 (Germany); Stokes, R. [CSSM, Department of Physics, University of Adelaide, Adelaide, SA, 5005 (Australia); Stüben, H. [Regionales Rechenzentrum, Universität Hamburg, Hamburg, 20146 (Germany); Young, R.D.; Zanotti, J.M. [CSSM, Department of Physics, University of Adelaide, Adelaide, SA, 5005 (Australia); Collaboration: the QCDSF and UKQCD collaboration

2016-04-15

In this paper we present results on the pseudoscalar meson masses from a fully dynamical simulation of QCD+QED, concentrating particularly on violations of isospin symmetry. We calculate the π{sup +}–π{sup 0} splitting and also look at other isospin violating mass differences. We have presented results for these isospin splittings in http://arxiv.org/abs/1508.06401. In this paper we give more details of the techniques employed, discussing in particular the question of how much of the symmetry violation is due to QCD, arising from the different masses of the u and d quarks, and how much is due to QED, arising from the different charges of the quarks. This decomposition is not unique, it depends on the renormalisation scheme and scale. We suggest a renormalisation scheme in which Dashen’s theorem for neutral mesons holds, so that the electromagnetic self-energies of the neutral mesons are zero, and discuss how the self-energies change when we transform to a scheme such as (MS)-bar , in which Dashen’s theorem for neutral mesons is violated.

Direct-current proton-beam measurements at Los Alamos

International Nuclear Information System (INIS)

Sherman, J.; Stevens, R.R.; Schneider, J.D.; Zaugg, T.

1994-01-01

Recently, a CW proton accelerator complex was moved from Chalk River Laboratories (CRL) to Los Alamos National Laboratory. This includes a 50-keV dc proton injector with a single-solenoid low-energy beam transport system (LEBT) and a CW 1.25-MeV, 267-MHz radiofrequency quadrupole (RFQ). The move was completed after CRL had achieved 55-mA CW operation at 1.25 MeV using 250-kW klystrode tubes to power the RFQ. These accelerator components are prototypes for the front end of a CW linac required for an accelerator-driven transmutation linac, and they provide early confirmation of some CW accelerator components. The injector (ion source and LEBT) and emittance measuring unit are installed and operational at Los Alamos. The dc microwave ion source has been operated routinely at 50-keV, 75-mA hydrogen-ion current. This ion source has demonstrated very good discharge and H 2 gas efficiencies, and sufficient reliability to complete CW RFQ measurements at CRL. Proton fraction of 75% has been measured with 550-W discharge power. This high proton fraction removes the need for an analyzing magnet. Proton LEBT emittance measurements completed at Los Alamos suggest that improved transmission through the RFQ may be achieved by increasing the solenoid focusing current. Status of the final CW RFQ operation at CRL and the installation of the RFQ at Los Alamos is given

The Los Alamos Space Science Outreach (LASSO) Program

Science.gov (United States)

Barker, P. L.; Skoug, R. M.; Alexander, R. J.; Thomsen, M. F.; Gary, S. P.

2002-12-01

The Los Alamos Space Science Outreach (LASSO) program features summer workshops in which K-14 teachers spend several weeks at LANL learning space science from Los Alamos scientists and developing methods and materials for teaching this science to their students. The program is designed to provide hands-on space science training to teachers as well as assistance in developing lesson plans for use in their classrooms. The program supports an instructional model based on education research and cognitive theory. Students and teachers engage in activities that encourage critical thinking and a constructivist approach to learning. LASSO is run through the Los Alamos Science Education Team (SET). SET personnel have many years of experience in teaching, education research, and science education programs. Their involvement ensures that the teacher workshop program is grounded in sound pedagogical methods and meets current educational standards. Lesson plans focus on current LANL satellite projects to study the solar wind and the Earth's magnetosphere. LASSO is an umbrella program for space science education activities at Los Alamos National Laboratory (LANL) that was created to enhance the science and math interests and skills of students from New Mexico and the nation. The LASSO umbrella allows maximum leveraging of EPO funding from a number of projects (and thus maximum educational benefits to both students and teachers), while providing a format for the expression of the unique science perspective of each project.

Oscillations of neutral B mesons systems

CERN Document Server

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

Hybrid mesons with auxiliary fields

International Nuclear Information System (INIS)

Buisseret, F.; Mathieu, V.

2006-01-01

Hybrid mesons are exotic mesons in which the color field is not in the ground state. Their understanding deserves interest from a theoretical point of view, because it is intimately related to nonperturbative aspects of QCD. Moreover, it seems that some recently detected particles, such as the π 1 (1600) and the Y(4260), are serious hybrid candidates. In this work, we investigate the description of such exotic hadrons by applying the auxiliary fields technique (also known as the einbein field method) to the widely used spinless Salpeter Hamiltonian with appropriate linear confinement. Instead of the usual numerical resolution, this technique allows to find simplified analytical mass spectra and wave functions of the Hamiltonian, which still lead to reliable qualitative predictions. We analyse and compare two different descriptions of hybrid mesons, namely a two-body q system with an excited flux tube, or a three-body qg system. We also compute the masses of the 1 -+ hybrids. Our results are shown to be in satisfactory agreement with lattice QCD and other effective models. (orig.)

Up sector of minimal flavor violation: top quark properties and direct D meson CP violation

Energy Technology Data Exchange (ETDEWEB)

Bai, Yang; Berger, Joshua; Hewett, JoAnne L.; Li, Ye

2013-07-01

Minimal Flavor Violation in the up-type quark sector leads to particularly interesting phenomenology due to the interplay of flavor physics in the charm sector and collider physics from flavor changing processes in the top sector. We study the most general operators that can affect top quark properties and D meson decays in this scenario, concentrating on two CP violating operators for detailed studies. The consequences of these effective operators on charm and top flavor changing processes are generically small, but can be enhanced if there exists a light flavor mediator that is a Standard Model gauge singlet scalar and transforms under the flavor symmetry group. This flavor mediator can satisfy the current experimental bounds with a mass as low as tens of GeV and explain observed D-meson direct CP violation. Additionally, the model predicts a non-trivial branching fraction for a top quark decay that would mimic a dijet resonance.

Nuclear matter studies with density-dependent meson-nucleon coupling constants

International Nuclear Information System (INIS)

Banerjee, M.K.; Tjon, J.A.; Banerjee, M.K.; Tjon, J.A.

1997-01-01

Due to the internal structure of the nucleon, we should expect, in general, that the effective meson nucleon parameters may change in nuclear medium. We study such changes by using a chiral confining model of the nucleon. We use density-dependent masses for all mesons except the pion. Within a Dirac-Brueckner analysis, based on the relativistic covariant structure of the NN amplitude, we show that the effect of such a density dependence in the NN interaction on the saturation properties of nuclear matter, while not large, is quite significant. Due to the density dependence of the g σNN , as predicted by the chiral confining model, we find, in particular, a looping behavior of the binding energy at saturation as a function of the saturation density. A simple model is described, which exhibits looping and which is shown to be mainly caused by the presence of a peak in the density dependence of the medium modified σN coupling constant at low density. The effect of density dependence of the coupling constants and the meson masses tends to improve the results for E/A and density of nuclear matter at saturation. From the present study we see that the relationship between binding energy and saturation density may not be as universal as found in nonrelativistic studies and that more model dependence is exhibited once medium modifications of the basic nuclear interactions are considered. copyright 1997 The American Physical Society

Short-distance matrix elements for $D$-meson mixing for 2+1 lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Chang, Chia Cheng [Univ. of Illinois, Champaign, IL (United States)

2015-01-01

We study the short-distance hadronic matrix elements for D-meson mixing with partially quenched N_f = 2+1 lattice QCD. We use a large set of the MIMD Lattice Computation Collaboration's gauge configurations with a² tadpole-improved staggered sea quarks and tadpole-improved Lüscher-Weisz gluons. We use the a² tadpole-improved action for valence light quarks and the Sheikoleslami-Wohlert action with the Fermilab interpretation for the valence charm quark. Our calculation covers the complete set of five operators needed to constrain new physics models for D-meson mixing. We match our matrix elements to the MS-NDR scheme evaluated at 3 GeV. We report values for the Beneke-Buchalla-Greub-Lenz-Nierste choice of evanescent operators.

The development of the atomic bomb, Los Alamos

Energy Technology Data Exchange (ETDEWEB)

Seidel, R.W.

1993-11-01

The historical presentation begins with details of the selection of Los Alamos as the site of the Army installation. Wartime efforts of the Army Corps of Engineers, and scientists to include the leader of Los Alamos, Robert Oppenheimer are presented. The layout and construction of the facilities are discussed. The monumental design requirements of the bombs are discussed, including but not limited to the utilization of the second choice implosion method of detonation, and the production of bomb-grade nuclear explosives. The paper ends with a philosophical discussion on the use of nuclear weapons.

Contribution to the study of mesons and their interactions with nuclei, by threshold production in low nucleon number systems; Contribution a l`etude des mesons et de leur interaction avec les noyaux, par production au seuil dans les systemes a petit nombre de nucleons

Energy Technology Data Exchange (ETDEWEB)

Roudot, F

1995-01-01

The threshold excitation function of the pd {yields} {sup 3}HeX reaction and the total {eta}-meson production cross section near threshold in the dd {yields} {alpha}{eta} reaction have been measured using the SPES4 beam line of the Laboratoire National Saturne. In the pd {yields} {sup 3}HeX threshold function, clear signals are observed at {omega}, {eta}` and {phi}6 mesons threshold; some structures appear at central masses of the a{sub 0} and f{sub 0}-mesons, as just above the two kaons production threshold. These structures could be the signature of new hadronic exotic states. The two-pion and two-kaon physical background has been estimated in a one-pion exchange model allowing the calculation of the differential cross section for the {pi}{sup -}p {yields} nX elementary process. The results of this calculation of the physical background of the threshold excitation function. The the dd {yields} {alpha}{eta} study, the {eta}-meson was clearly observed in the spectrometer`s final focal plane spectra, in good agreement with a Monte Carlo simulation. A total cross section of the order of the nano-barn has been measured. The results are compared to some other {eta}-meson production processes with lighter nuclei than helium-4. Using different nuclei a comparative study of the {eta}-nucleus interaction has shown that the latter is more binding in the helium-4 case. Based on these data, the charge symmetry breaking in the dd {yields} {alpha}{pi}{sup 0} reaction is studied. Using a {pi}{sup 0}-{eta} mixing model, the extracted cross sections are compatible with the only measurement of this reaction cross section. (author). 59 refs.

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

International Nuclear Information System (INIS)

1984-11-01

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, 12 C(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 12 C via 13 C(p,d) 12 C* at 800 MeV

Los Alamos Programming Models

Energy Technology Data Exchange (ETDEWEB)

Bergen, Benjamin Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-07-07

This is the PDF of a powerpoint presentation from a teleconference on Los Alamos programming models. It starts by listing their assumptions for the programming models and then details a hierarchical programming model at the System Level and Node Level. Then it details how to map this to their internal nomenclature. Finally, a list is given of what they are currently doing in this regard.

Publications of Los Alamos research 1988

International Nuclear Information System (INIS)

Varjabedian, K.; Dussart, S.A.; McClary, W.J.; Rich, J.A.

1989-12-01

This bibliography lists unclassified publications of work done at the Los Alamos National Laboratory for 1988. The entries, which are subdivided by broad subject categories, are cross-referenced with an author index and a numeric index

Publications of Los Alamos research 1988

Energy Technology Data Exchange (ETDEWEB)

Varjabedian, K.; Dussart, S.A.; McClary, W.J.; Rich, J.A. (comps.)

1989-12-01

This bibliography lists unclassified publications of work done at the Los Alamos National Laboratory for 1988. The entries, which are subdivided by broad subject categories, are cross-referenced with an author index and a numeric index.

Science and Innovation at Los Alamos

Science.gov (United States)

Alamos National Laboratory Delivering science and technology to protect our nation and promote world stability Science & Innovation Collaboration Careers Community Environment Science & Innovation Facilities Science Pillars Research Library Science Briefs Science News Science Highlights Lab Organizations

On wave functions of mesons involving the s-, c- and b-quarks

International Nuclear Information System (INIS)

Zhitnitskij, A.R.; Zhitnitskij, I.R.; Chernyak, V.L.

1983-01-01

The wave function components of pseudoscalar and vestor mesons which are antisymmertric with respect to permutation of the quark momenta are studied. The results are as follows: elt xsub(s)-xsub(u) > sub(K) approximately equal to 0.11 for the K meson, sub(K*) approximately equal to 0.15-C.20 for the K* meson, being a mean fraction of the longitudinal momentum transferred by the s(u) quark. The following estimates are obtained: / approximately equal to 0.20-0.25; / approximately equal to 0.8x10 -2 . The asymptotics of the K 0 -meson form factor and the etasub(c) → KK* decay width are found. Properties of the wave functions of mesons which contain a light and a heavy quark (D, B, ...) are considered. For the B 0 meson approximately equal to 0.10 is found. Arguments are given supporting nonenhancement of the amplitudes of the processes involving D mesons compared to similar K-meson amplitudes. A simple way is suggested to determine the asymptotic form of various wave functions

A lattice QCD determination of potentials between pairs of static-light mesons

International Nuclear Information System (INIS)

Hetzenegger, Martin

2011-01-01

Potentials between pairs of static-light mesons are interesting in a sense that they give insights in the nature of strong interactions from first principles for multiquark systems. For large heavy quark masses, e.g., the spectra of heavy-light mesons are determined by excitations of the light quark and gluonic degrees of freedom. In particular, the vector-pseudoscalar splitting vanishes and a static-light meson can be interpreted as either a B, a B * , a D or a D * heavy-light meson. Calculating potentials between two static-light mesons also enables investigations of possible bound tetraquark states or for particles that are close to the meson-antimeson threshold, such as the X(3872) or the Z + (4430).

Flavour Physics and CP Violation

CERN Document Server

Fleischer, Robert

2005-01-01

The starting point of these lectures is an introduction to the weak interactions of quarks and the Standard-Model description of CP violation, where the key element is the Cabibbo--Kobayashi--Maskawa matrix and the corresponding unitarity triangles. Since the B-meson system will govern the stage of (quark) flavour physics and CP violation in this decade, it will be -- after a brief look at the kaon system -- our main focus. We shall classify B-meson decays, introduce the theoretical tools to deal with them, explore the requirements for non-vanishing CP-violating asymmetries, and discuss B^0_q--B^0_q_bar mixing (q={d,s}). We will then turn to B-factory benchmark modes, discuss the physics potential of B^0_s mesons, which is particularly promising for B-decay experiments at hadron colliders, and emphasize the importance of studies of rare decays, which are absent at the tree level in the Standard Model, complement nicely the studies of CP violation, and provide interesting probes for new physics.

Multiple production of mesons in Au+Au and Pb+Pb collisions

CERN Document Server

Guptaroy, P; Bhattacharya, D P; Bhattacharya, S

2003-01-01

The study presented here pertains to the model-based analyses for production of some important charged secondaries in lead-lead and gold-gold collisions at AGS, SPS and RHIC energies. We examine the role of a particular version of the Sequential Chain Model (SCM) in interpreting the data on the production of only the secondary mesons of the most abundant variety in relativistic nucleus-nucleus collisions. The initial results derived for basic pp collisions have been transformed into the corresponding cases for nucleus-nucleus collisions through the appropriate physical-mathematical formalisms. The agreement between the model of choice and the measured data for the most important varieties of mesons in the two above-stated nuclear collisions could so far be rated to be barely modest. This is presumably due to our neglect of the effects of rescattering and cascading, while we choose to obtain only the first-order results in the initial attempt. (47 refs).

About direct CP violation in the system of K0 mesons

International Nuclear Information System (INIS)

Beshtoev, Kh.M.

2012-01-01

This work is devoted to computation of the parameter of direct CP violation by the weak interactions in the system of K 0 mesons at K 1 0 -, K 2 0 -meson mixings and oscillations via K S -, K L -meson states

Mixed meson masses with domain-wall valence and staggered sea fermions

International Nuclear Information System (INIS)

Orginos, Kostas; Walker-Loud, Andre

2008-01-01

Mixed action lattice calculations allow for an additive lattice-spacing-dependent mass renormalization of mesons composed of one sea and one valence quark, regardless of the type of fermion discretization methods used in the valence and sea sectors. The value of the mass renormalization depends upon the lattice actions used. This mixed meson mass shift is an important lattice artifact to determine for mixed action calculations; because it modifies the pion mass, it plays a central role in the low-energy dynamics of all hadronic correlation functions. We determine the leading order, O(a 2 ), and next-to-leading order, O(a 2 m π 2 ), additive mass shift of valence-sea mesons for a mixed lattice action with domain-wall valence fermions and rooted staggered sea fermions, relevant to the majority of current large scale mixed action lattice efforts. We find that, on the asqtad-improved coarse MILC lattices, this additive mass shift is well parametrized in lattice units by Δ(am) 2 =0.034(2)-0.06(2)(am π ) 2 , which in physical units, using a=0.125 fm, corresponds to Δ(m) 2 =(291±8 MeV) 2 -0.06(2)m π 2 . In terms of the mixed action effective field theory parameters, the corresponding mass shift is given by a 2 Δ Mix =(316±4 MeV) 2 at leading order plus next-to-leading order corrections including the necessary chiral logarithms for this mixed action calculation, determined in this work. Within the precision of our calculation, one cannot distinguish between the full next-to-leading order effective field theory analysis of this additive mixed meson mass shift and the parametrization given above.

Mesonic atom production in high-energy nuclear collisions

International Nuclear Information System (INIS)

Wakai, M.; Bando, H.; Sano, M.

1987-08-01

The production probability of π-mesonic atom in high-energy nuclear collisions is estimated by a coalescence model. The production cross section is calculated for p + Ne and Ne + Ne systems at 2.1 GeV/A and 5.0 GeV/A beam energy. It is shown that nuclear fragments with larger charge numbers have the advantage in the formation of π-mesonic atoms. The cross section is proportional to Z 3 and of the order of magnitude of 1 ∼ 10 μb in all the above cases. The production cross sections of K-mesonic atoms are also estimated. (author)

Light meson decays in CLAS and CLAS12

Energy Technology Data Exchange (ETDEWEB)

Kunkel, Michael [Forschungszentrum Juelich (Germany); Collaboration: CLAS Collaboration

2016-07-01

Photoproduction experiments with the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Facility produce data sets with competitive statistics of light mesons. With these data sets, measurements of transition form factors for η, ω, and η' mesons via conversion decays can be performed using the invariant mass distribution of the final state dileptons. Tests of fundamental symmetries and information on the light quark mass difference can be performed using a Dalitz plot analysis of the meson decay. An overview of preliminary results, from existing CLAS data, and future prospects within the newly upgraded CLAS12 apparatus are given.

On the mesonic-exchange currents in the photomesic reactions

International Nuclear Information System (INIS)

Lazard, C.; Maric, Z.; Zivanovic, D.

1979-02-01

The γd→π 0 d reaction is analysed in the framework of the relativistic many-body theory with mesonic degrees of freedom explicitly present. It is shown that the mesonic correlations can be grouped into transition operators containing vertices of some elementary reactions between photon, nucleons and pions. The wave function corrections due to meson exchange currents are included in the transition operators and the S-matrix is obtained with the non relativistic deuteron wave function

Finite temperature QCD sum rule and the ρ-meson

International Nuclear Information System (INIS)

Liu Jueping; Jin Yaping

1995-01-01

The contributions from the three-gluon condensates to the finite temperature QCD sum rule for the ρ-meson are calculated, and then the dependence of the properties of the ρ-meson upon temperature is investigated in a string model of condensates. The results show that the parameters characterizing the properties of the ρ-meson change noticeably when the temperature closes to the critical temperature of the condensates, and if the critical temperatures of condensates are the same

Radiative decays of B mesons at LHCb

CERN Document Server

Soomro, Fatima; Golutvin, Andrei

2011-01-01

This thesis is dedicated to the study of radiative decays of $B$ mesons at LHC$b$. At quark level, such decays are a $b\\to s\\gamma$ transition and take place via a penguin loop and are sensitive to virtual contribution of New Physics, which can be indicated by an increase in the decay rates. These decays also offer the possibility to test the V-A structure of the Standard Model coupling in the processes mediated by loop penguin diagrams. In the decay $B_s \\to \\phi\\gamma$, New Physics contribution can be probed by measuring the polarization of the photon in this decay. Systematic effects in the proper time reconstruction of the $B_s$ in $B_s \\to \\phi\\gamma$ can bias the photon polarization measurement in this decay, which will reduce the sensitivity on the relevant New Physics parameter. The author studied those effects and developed ideas to calibrate them using $B_d\\to K^{*}\\gamma$ and $B_s\\to J/\\psi\\phi$ decays as control channels. These studies are mostly Monte Carlo based due to a relatively small data ...

The process F+- → Pπ+- as a mean for determining the strange content of eta'(iota) and the nature of the iota-meson

International Nuclear Information System (INIS)

Bediaga, I.; Caruso, F.; Predazzi, E.

1986-01-01

Several tests that have been proposed to determine the various components (nonstrange, strange and gluonic) of the pseudoscalar mesons eta-eta'-iota are briefly reviewed. The constraints provided by these tests do not allow an unambiguous determination of the strange components of the eta' and iota mesons. It is suggested that this would follow from the experimental measurement of the branching ratios BR(F +- → eta'π +- ) and BR(F +- → iotaπ +- ). The decay F +- → iotaπ +- , in particular, would be crucial to understand the physical nature of the iota-meson or, differently stated, to establish (or to disprove) the validity of the eta-eta'-iota mixing

Hadronic physics of q anti q light quark mesons, quark molecules and glueballs

International Nuclear Information System (INIS)

Lindenbaum, S.J.

1980-10-01

A brief introduction reviews the development of QCD and defines quark molecules and glueballs. This review is concerned primarily with u, d, and s quarks, which provide practically all of the cross section connected with hadronic interactions. The following topics form the bulk of the paper: status of quark model classification for conventional u, d, s quark meson states; status of multiquark or quark molecule state predictions and experiments; glueballs and how to find them; and the OZI rule in decay and production and how glueballs might affect it. 17 figures, 1 table

Scalar meson field and many-body forces. Chapter 23

International Nuclear Information System (INIS)

Nyman, E.M.

1979-01-01

In applications of field theory to the theory of the nuclear forces, one has frequently assumed that there is a scalar meson. It will then be responsible for most of the medium-range attraction between the nucleons. According to current ideas, however, it is possible to account for the medium-range attraction without an elementary sigma meson. This approach requires a careful treatment of the exchange of interacting pairs of π mesons, such as to include those ππ interactions which are responsible for the formation and decay of the sigma meson. Recently, the scalar field in the nuclear many-body problem has begun to receive more attention. There are two reasons for this change of philosophy. One reason is the discovery of neutron stars. In neutron stars, the nucleon number density can be much higher than in nuclei. One therefore wants to derive the equation of state from a relativistic many-body theory. This forces one to deal explicitly with a set of mesons, such that in the non-relativistic limit one recovers the one-boson-exchange potential. (Auth.)

$B$- and $D$-meson leptonic decay constants from four-flavor lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Bazavov, A. [Michigan State U.; Bernard, C. [Washington U., St. Louis; Brown, N. [Washington U., St. Louis; Detar, C. [Utah U.; El-Khadra, A. X. [Fermilab; Gámiz, E. [Granada U., Theor. Phys. Astrophys.; Gottlieb, Steven [Indiana U.; Heller, U. M. [APS, New York; Komijani, J. [TUM-IAS, Munich; Kronfeld, A. S. [TUM-IAS, Munich; Laiho, J. [Syracuse U.; Mackenzie, P. B. [Fermilab; Neil, E. T. [RIKEN BNL; Simone, J. N. [Fermilab; Sugar, R. L. [UC, Santa Barbara; Toussaint, D. [Glasgow U.; Van De Water, R. S. [Fermilab

2017-12-26

We calculate the leptonic decay constants of heavy-light pseudoscalar mesons with charm and bottom quarks in lattice quantum chromodynamics on four-flavor QCD gauge-field configurations with dynamical $u$, $d$, $s$, and $c$ quarks. We analyze over twenty isospin-symmetric ensembles with six lattice spacings down to $a\\approx 0.03$~fm and several values of the light-quark mass down to the physical value $\\frac{1}{2}(m_u+m_d)$. We employ the highly-improved staggered-quark (HISQ) action for the sea and valence quarks; on the finest lattice spacings, discretization errors are sufficiently small that we can calculate the $B$-meson decay constants with the HISQ action for the first time directly at the physical $b$-quark mass. We obtain the most precise determinations to-date of the $D$- and $B$-meson decay constants and their ratios, $f_{D^+} = 212.6 (0.5)$~MeV, $f_{D_s} = 249.8(0.4)$~MeV, $f_{D_s}/f_{D^+} = 1.1749(11)$, $f_{B^+} = 189.4(1.4)$~MeV, $f_{B_s} = 230.7(1.2)$~MeV, $f_{B_s}/f_{B^+} = 1.2180(49)$, where the errors include statistical and all systematic uncertainties. Our results for the $B$-meson decay constants are three times more precise than the previous best lattice-QCD calculations, and bring the QCD errors in the Standard-Model predictions for the rare leptonic decays $\\overline{\\mathcal{B}}(B_s \\to \\mu^+\\mu^-) = 3.65(11) \\times 10^{-9}$, $\\overline{\\mathcal{B}}(B^0 \\to \\mu^+\\mu^-) = 1.00(3) \\times 10^{-11}$, and $\\overline{\\mathcal{B}}(B^0 \\to \\mu^+\\mu^-)/\\overline{\\mathcal{B}}(B_s \\to \\mu^+\\mu^-) = 0.00264(7)$ to well below other sources of uncertainty. As a byproduct of our analysis, we also update our previously published results for the light-quark-mass ratios and the scale-setting quantities $f_{p4s}$, $M_{p4s}$, and $R_{p4s}$. We obtain the most precise lattice-QCD determination to date of the ratio $f_{K^+}/f_{\\pi^+} = 1.1950(^{+15}_{-22})$~MeV.

Scattering of vector mesons off nucleons

International Nuclear Information System (INIS)

Lutz, M.F.M.; Friman, B.; Wolf, G.

2001-12-01

We construct a relativistic and unitary approach to 'high' energy pion- and photon-nucleon reactions taking the πN, πΔ, ρN, ωN, ηN, K Λ, KΣ final states into account. Our scheme dynamically generates the s- and d-wave nucleon resonances N(1535), N(1650) and N(1520) and isobar resonances Δ(1620) and δ(1700) in terms of quasi-local interaction vertices. The description of photon-induced processes is based on a generalized vector-meson dominance assumption which directly relates the electromagnetic quasi-local 4-point interaction vertices to the corresponding vertices involving the ρ and ω fields. We obtain a satisfactory description of the elastic and inelastic pion- and photon-nucleon scattering data in the channels considered. The resulting s-wave ρ- and ω-nucleon scattering amplitudes are presented. Using these amplitudes we compute the leading density modification of the ρ and ω mass distributions in nuclear matter. We find a repulsive mass shift for the ω meson at small nuclear density but predict considerable strength in resonance-hole like ω-meson modes. Compared to previous calculations our result for the ρ-meson spectral function shows a significantly smaller in-medium effect. This reflects a not too large coupling strength of the N(1520) resonance to the ρN channel. (orig.)

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.)

Smart instrumentation development at Los Alamos

International Nuclear Information System (INIS)

Erkkila, B.

1984-01-01

For several years Los Alamos has incorporated microprocessors into instruments to expand the capability of portable survey type equipment. Beginning with portable pulse height analyzers, the developments have expanded to small dedicated instruments which handle the measurement and interpretation of various radiation fields. So far, instruments to measure gamma rays, neutrons, and beta particles have been produced. The computer capability built into these instruments provides significant computational power into the instruments. Capability unheard of a few years ago in small portable instruments is routine today. Large computer-based laboratory measurement systems which required much space and electrical power can now be incorporated in a portable hand-held instrument. The microprocessor developments at Los Alamos are now restricted to radiation monitoring equipment but can be expanded to chemical and biological applications as well. Applications for radiation monitoring equipment and others are discussed

A lattice QCD determination of potentials between pairs of static-light mesons

Energy Technology Data Exchange (ETDEWEB)

Hetzenegger, Martin

2011-07-04

Potentials between pairs of static-light mesons are interesting in a sense that they give insights in the nature of strong interactions from first principles for multiquark systems. For large heavy quark masses, e.g., the spectra of heavy-light mesons are determined by excitations of the light quark and gluonic degrees of freedom. In particular, the vector-pseudoscalar splitting vanishes and a static-light meson can be interpreted as either a B, a B{sup *}, a D or a D{sup *} heavy-light meson. Calculating potentials between two static-light mesons also enables investigations of possible bound tetraquark states or for particles that are close to the meson-antimeson threshold, such as the X(3872) or the Z{sup +}(4430).

δ meson effects in the Nolen-Schiffer anomaly

International Nuclear Information System (INIS)

Menezes, D.P.; Avancini, S.S.; Vasconcellos, C.Z.; Razeira, M.

2009-01-01

In this work we revisit the Okamoto-Nolen-Schiffer (ONS) anomaly in the context of four parametrizations of effective hadronic models, two of them with constant couplings between the nucleons and the mesons and two with density-dependent couplings. A Thomas-Fermi approximation is performed and the effects of the isovector-scalar virtual δ (a 0 (980)) mesons are investigated since they influence directly the proton and neutron effective masses in opposite ways. The ρ-ω mixing term is claimed to be important in the explanation of the ONS anomaly and is added in our calculations. We have concluded that as far as the ρ-ω mixing term is included, Δ M(Z, N) is clearly larger in models with δ than in models where this meson is not considered, which is not always the case if the coupling is discarded. None of the models is good enough to describe all experimental data, but the models that better describe the experimental values include the δ mesons. (orig.)

Meson masses in electromagnetic fields with Wilson fermions

Science.gov (United States)

Bali, G. S.; Brandt, B. B.; Endrődi, G.; Gläßle, B.

2018-02-01

We determine the light meson spectrum in QCD in the presence of background magnetic fields using quenched Wilson fermions. Our continuum extrapolated results indicate a monotonous reduction of the connected neutral pion mass as the magnetic field grows. The vector meson mass is found to remain nonzero, a finding relevant for the conjectured ρ -meson condensation at strong magnetic fields. The continuum extrapolation was facilitated by adding a novel magnetic field-dependent improvement term to the additive quark mass renormalization. Without this term, sizable lattice artifacts that would deceptively indicate an unphysical rise of the connected neutral pion mass for strong magnetic fields are present. We also investigate the impact of these lattice artifacts on further observables like magnetic polarizabilities and discuss the magnetic field-induced mixing between ρ -mesons and pions. We also derive Ward-Takashi identities for QCD +QED both in the continuum formulation and for (order a -improved) Wilson fermions.

Vector meson decays in the chiral bag model

International Nuclear Information System (INIS)

Maxwell, O.V.; Jennings, B.K.

1985-01-01

Vector meson decays are examined in a model where a confined quark and antiquark annihilate, producing a pair of elementary pseudoscalar mesons. Two versions of the pseudoscalar meson-quark interaction are employed, one where the coupling is restricted to the bag surface and one where it extends throughout the bag volume. Energy conservation is ensured in the model through insertion of exponential factors containing the bag energy at each interaction vertex. To guarantee momentum conservation, a wave-packet description is utilized in which the decay widths are normalized by a factor involving the overlap of the initial bag state with the confined qanti q state of zero momentum. With either interaction, the model yields a value for the p-width that exceeds the empirical width by a factor two. For the Ksup(*) and PHI mesons, the computed widths depend strongly on the interaction employed. Implications of these results for chiral bag models are discussed. (orig.)

RFQ development at Los Alamos

International Nuclear Information System (INIS)

Wangler, T.P.; Crandall, K.R.; Stokes, R.H.

1982-01-01

The basic principles of the radio-frequency quadrupole (RFQ) linac are reviewed and a summary of past and present Los Alamos work is presented. Some beam-dynamics effects, important for RFQ design, are discussed. A design example is shown for xenon and a brief discussion of low-frequency RFQ structures is given

B physics at the tevatron

International Nuclear Information System (INIS)

1998-07-01

Precision B-physics results from the CDF and D0 Collaborations based on data collected during the Tevatron 1992-96 run are presented. In particular we discuss the measurement of the B s meson lifetime, B c meson observation, and B 0 - anti B 0 mixing results obtained using time-evolution analyses. Prospects for the next Tevatron run, starting in 1999, are also reported

Skyrmions and vector mesons: a symmetric approach

International Nuclear Information System (INIS)

Caldi, D.G.

1984-01-01

We propose an extension of the effective, low-energy chiral Lagrangian known as the Skyrme model, to one formulated by a non-linear sigma model generalized to include vector mesons in a symmetric way. The model is based on chiral SU(6) x SU(6) symmetry spontaneously broken to static SU(6). The rho and other vector mesons are dormant Goldstone bosons since they are in the same SU(6) multiplet as the pion and other pseudoscalars. Hence the manifold of our generalized non-linear sigma model is the coset space (SU(6) x SU(6))/Su(6). Relativistic effects, via a spin-dependent mass term, break the static SU(6) and give the vectors a mass. The model can then be fully relativistic and covariant. The lowest-lying Skyrmion in this model is the whole baryonic 56-plet, which splits into the octet and decuplet in the presence of relativistic SU(6)-breaking. Due to the built-in SU(6) and the presence of vector mesons, the model is expected to have better phenomenological results, as well as providing a conceptually more unified picture of mesons and baryons. 29 references

Hard production of exotic hybrid mesons

Energy Technology Data Exchange (ETDEWEB)

Anikin, I.; Teryaev, O.V. [Bogoliubov Lab. of Theoretical Physics, JINR, Dubna (Russian Federation); Pire, B.; Anikin, I. [Ecole Polytechnique, CPHT, 91 - Palaiseau (France); Szymanowski, I. [Soltan Institute for Nuclear Studies, Warsaw (Poland); Liege Univ. (Belgium); Anikin, I.; Wallon, S. [Paris-11 Univ., Lab. de Physique Theorique, 91 - Orsay (France)

2005-07-01

Exotic hybrid mesons H, with quantum numbers J{sup PC} = 1{sup -+} may be copiously produced in the hard exclusive processes {gamma}{sup *}(Q{sup 2}){gamma} {yields} H and {gamma}{sup *}(Q{sup 2})P(p) {yields} HP(p') because they have a leading twist distribution amplitude with a sizable coupling constant f{sub H}, which may be estimated through QCD sum rules. The reaction rates scale in the same way as the corresponding rates for usual mesons. (authors)

Summary of environmental surveillance at Los Alamos during 1995

International Nuclear Information System (INIS)

1996-10-01

Linking the Rio Grande Valley and the Jemez Mountains, New Mexico's Pajarito Plateau is home to a world-class scientific institution. Los Alamos National Laboratory (or the Laboratory), managed by the Regents of the University of California, is a government-owned, Department of Energy-supervised complex investigating all areas of modern science for the purposes of national defense, health, conservation, and ecology. The Laboratory was founded in 1943 as part of the Manhattan Project, whose members assembled to create the first nuclear weapon. Occupying the campus of the Los Alamos Ranch School, American and British scientists gathered on the isolated mesa tops to harness recently discovered nuclear power with the hope of ending World War II. In July 1945, the initial objective of the Laboratory, a nuclear device, was achieved in Los Alamos and tested in White Sands, New Mexico. Today the Laboratory continues its role in defense, particularly in nuclear weapons, including developing methods for safely handling weapons and managing waste. For the past twenty years, the Laboratory has published an annual environmental report. This pamphlet offers a synopsis that briefly explains important concepts, such as radiation and provides a summary of the monitoring results and regulatory compliance status that are explained at length in the document entitled Environmental Surveillance at Los Alamos during 1995

Los Alamos DP West Plutonium Facility decontamination project

International Nuclear Information System (INIS)

Garde, R.; Cox, E.J.; Valentine, A.M.

1982-01-01

The DP West Plutonium Facility operated by the Los Alamos National Laboratory, Los Alamos, New Mexico, was decontaminated between April 1978 and April 1981. The facility was constructed in 1944 to 1945 to produce plutonium metal and fabricate parts for nuclear weapons. It was continually used as a plutonium processing and research facility until mid-1978. Decontamination operations included dismantling and removing gloveboxes and conveyor tunnels; removing process systems, utilities, and exhaust ducts; and decontaminating all remaining surfaces. This report describes glovebox and conveyor tunnel separations, decontamination techniques, health and safety considerations, waste management procedures, and costs of the operation

QCD sum rules for the decay amplitudes of pseudoscalar mesons

International Nuclear Information System (INIS)

Narison, S.

1981-07-01

Bounds on the π and K meson decay amplitudes are obtained to a good accuracy from QCD sum rules of the Laplace transform type. A relation between fsub(π) and the rho meson coupling to the photon is given. Using the heavy quarks q 2 =0 sum rule to two loops we find our best bounds: fsub(D) approximately < (101+-25) MeV and fsub(F) approximately < (147+-41.6) MeV to be compared to fsub(π) approximately 93.3 MeV. We also derive a relation between the D and F meson masses and the charm quark mass. Our results are extended to the beautiful B mesons. (author)

Mesons versus quasi-normal modes: undercooling and overheating

NARCIS (Netherlands)

Paredes Galan, A.; Peeters, K.; Zamaklar, m.

2008-01-01

In holographic models of gauge theories with matter, there generically exists a first order phase transition in which mesons dissociate. We perform a careful analysis of the meson and quasi-particle spectra in the overheated resp. undercooled regimes close to the junction of the two phases. We show

Electro- and chromomagnetism in the charm meson spectrum

International Nuclear Information System (INIS)

Fritzsch, H.

1977-01-01

How the D and F meson spectrum is influenced by the chromomagnetic and electomagnetic hyperfine interaction is discussed. In particular a relation between the hyperfine splitting of charmed mesons and the magnetic moments of the baryons is derived. M(Fsub(+)*)-M(Fsub(+)) approximately 100+-8 MeV. (Auth.)

Measurements of transient electromagnetic propagation through concrete and sand

Energy Technology Data Exchange (ETDEWEB)

Aurand, J.F.

1996-09-01

This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). If a beam-chopping system could be developed for the Los Alamos Meson Physics Facility low-energy beam line, there would be potential to operate the Los Alamos Neutron Scattering Center (LANSCE) at much higher power and duty factor and enable such operation with a radio-frequency quadrapole (RFQ) injector. This would greatly extend the capability of the facility. To accommodate LANSCE operation in the new configuration, a chopped beam must be created in the low-energy transport line before the RFQ. Chopping in this region has never been demonstrated and constitutes the major uncertainty of the proposal and determines the critical path for project completion. This study produces a better understanding of the physics involved in chopping an H-beam in a dilute plasma background, and in transporting a chopped H-beam through a neutralized or partially neutralized plasma channel, as well as an estimate for the optimum neutralization strategy for the beam chopping and transport between the ion source and the RFQ.

Elements of beauty physics

International Nuclear Information System (INIS)

Morenas, V.

2006-11-01

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.)

Semileptonic decays of the Bc meson

International Nuclear Information System (INIS)

Barik, N.; Naimuddin, Sk.; Dash, P. C.; Kar, Susmita

2009-01-01

We study the semileptonic transitions B c →η c ,J/Ψ,D,D*,B,B*,B s ,B s * in the leading order in the framework of a relativistic independent quark model based on a confining potential in the equally mixed scalar-vector harmonic form. We compute relevant weak form factors as overlap integrals of the meson-wave functions obtained in the relativistic independent quark model in the whole accessible kinematical range. We predict that the semileptonic transitions of the B c meson are mostly dominated by two Cabibbo-Kobayashi-Maskawa (CKM)-favored modes, B c →B s (B s *)eν, contributing about 77% of the total decay width, and its decays to vector meson final states take place in the predominantly transverse mode. Our predicted values for the total decay rates, branching ratios, polarization ratios, the forward-backward asymmetry factor, etc., are broadly in agreement with other model predictions.

Κ-meson decays and parity violation

International Nuclear Information System (INIS)

Dalitz, R.H.

1989-01-01

Between 1948 and 1954 many Κ-meson decay modes were observed, including the tau, pion and xi positives, in emulsion experiments all with masses around 500 MeV. An attempt was made to rationalize the various names for the new particles being discovered. A period of experimental consolidation followed. An attempt was then made to determine the spin parity of the three-pion system from tau plus decay using matrix calculations. New stripped emulsion techniques now permitted a secondary-particle track to be followed to its endpoint. Stacked emulsions were flown in balloons to study Κ mesons and hyperons using cosmic radiation. Later similar work used the new particle accelerators, the Cosmotron and the Bevatron as sources. The author showed that the tau plus and theta plus were competing decay modes of the same Κ + meson, but this meant that parity conservation was violated. Later theoreticians T D Lee and C N Yang provided evidence for this surprising idea from their work on semileptonic weak interactions. (UK)

{phi} meson electroproduction at small Bjorken-x

Energy Technology Data Exchange (ETDEWEB)

Kroll, P. [Wuppertal Univ., Fachbereich Physik (Germany)

2005-07-01

It is reported on an analysis of {phi}-meson electroproduction at small Bjorken-x(x{sub B{sub j}}) within the handbag approach. The amplitudes can be factorized into generalized parton distribution (GPDs) and a partonic subprocess, electroproduction off gluons. Cross-sections and spin density matrix elements are evaluated for {phi}-meson electroproduction and found to be in fair agreement with recent HERA data. (author)

Beautiful mesons from QCD spectral sum rules

International Nuclear Information System (INIS)

Narison, S.

1991-01-01

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 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.)

Static-light meson masses from twisted mass lattice QCD

International Nuclear Information System (INIS)

Jansen, Karl; Michael, Chris; Shindler, Andrea; Wagner, Marc

2008-08-01

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 MeV PS S mesons. (orig.)

Magnetic polarizabilities of light mesons in SU(3 lattice gauge theory

Directory of Open Access Journals (Sweden)

E.V. Luschevskaya

2015-09-01

Full Text Available We investigate the ground state energies of neutral pseudoscalar and vector meson in SU(3 lattice gauge theory in the strong abelian magnetic field. The energy of ρ0 meson with zero spin projection sz=0 on the axis of the external magnetic field decreases, while the energies with non-zero spins sz=−1 and +1 increase with the field. The energy of π0 meson decreases as a function of the magnetic field. We calculate the magnetic polarizabilities of pseudoscalar and vector mesons for lattice volume 184. For ρ0 with spin |sz|=1 and π0 meson the polarizabilities in the continuum limit have been evaluated. We do not observe any evidence in favour of tachyonic mode existence.

Vector mesons in meson-baryon scattering and large-N{sub c} quantum chromodynamics

Energy Technology Data Exchange (ETDEWEB)

Fuhrmann, Hans-Friedrich

2016-02-11

We examined strong interactions in the low-energy regime in terms of two complementary non-perturbative approaches: the interplay of large-N{sub c} QCD and chiral perturbation theory was studied. While the expansion in the parameter 1/N{sub c} is based on quark and gluon degrees of freedom, chiral perturbation theory uses hadrons as effective degrees of freedom. The focus of our work was the investigation of mesons and baryons composed from up-, down- and strange quarks. We used the chiral SU(3) Lagrangian with (J{sup P}=(1)/(2){sup +})- and (J{sup P}=(3)/(2){sup +})-baryon ground states as building blocks. In the SU(3)-flavour limit the latter form an octet and a decuplet, respectively. Studies in chiral perturbation theory hold a challenge: the chiral Lagrangian consists of an infinite number of terms. The treatment of low-energy QCD physics via a perturbation theory requires the ordering of these terms according to their relevance. We used the interplay between large-N{sub c} QCD and chiral perturbation theory to shed light on the structure of the chiral Lagrangian. In the limit of large-N{sub c} the low-energy parameters of the chiral Lagrangian are correlated. For instance the masses of the two baryon multiplets turn degenerate in the SU(3)-flavour limit. This serves as the starting point of our investigations. In this work we analysed the time-ordered product of two scalar and two vector currents in the baryon ground state. The examination of these matrix elements at large-N{sub c} was compared to corresponding results derived in chiral perturbation theory. From this we obtained sum rules for some low-energy parameters of the chiral Lagrangian. The results for the vector correlation function were used to constrain a phenomenological interaction of light vector mesons with the baryon ground states. In the second part of this thesis we addressed a formal problem which arises in a partial wave decomposition of reaction amplitudes for particles with non

Study of the meson mass spectroscopy with a potential model inspired in the quantum chromodynamics

International Nuclear Information System (INIS)

Bernardini, Alex Eduardo de

2001-01-01

Since the discovery of QCD (Quantum Chromodynamics), there have been remarkable technical achievements in perturbative calculations applied to hadrons. However, it is difficult to use QCD directly to compute hadronic properties. In this context, phenomenological potential models have provided extremely satisfactory results on description of ordinary hadrons, more specifically about quark-antiquark bound states (mesons). In this work we propose and study the main aspects in the construction of a potential model and search a generalized description of meson spectroscopy, with emphasis in heavy quark bound states. We analyze important aspects in the choice of the treatment in good agreement with the dynamics of interacting particles, attempting to relativistic aspects as well as to the possibilities of nonrelativistic approximation analysis. Initially the 'soft QCD' is employed to determine effective potential terms establishing the asymptotic Coulomb term from one gluon exchange approximation. At the same time, a linear confinement term is introduced in accordance with QCD and phenomenological prescription. We perform the calculations of mass spectroscopy for particular sets of mesons and we verify whether the potential model could be extended to calculating the electronic transition rate (Γ(q q-bar → e - e + )). Finishing, we discuss the real physical possibilities of development of a generalized potential model (all quark flavors), its possible advantages relative to experimental parametrization, complexity in numerical calculations and in the description of physical reality in agreement with a quantum field theory (QCD). (author)

A survey of E/iota meson in hadroproduction

International Nuclear Information System (INIS)

Chung, S.U.

1987-01-01

The E(1420) meson has been around with us since 1963, when its observation was first reported by R. Armenteros et al. With the discovery of the iota(1460) in the same decay channel from J/ψ radiative decays in 1980, there has been a resurgence of interest in this meson because it may turn out to be a pseudoscalar glueball. This review covers the E/iota states seen in hadroproduction, while an update of the iota meson from J/ψ radiative decays is covered by D. Hitlin in this volume. The present review represents an updated version of the previous reviews given by the author at Lund, Leipzig, and Santander

Semileptonic Branching Fractions of Charged and Neutral B Mesons

International Nuclear Information System (INIS)

Athanas, M.; Brower, W.; Masek, G.; Paar, H.P.; Gronberg, J.; Kutschke, R.; Menary, S.; Morrison, R.J.; Nakanishi, S.; Nelson, H.N.; Nelson, T.K.; Qiao, C.; Richman, J.D.; Ryd, A.; Tajima, H.; Sperka, D.; Witherell, M.S.; Balest, R.; Cho, K.; Ford, W.T.; Johnson, D.R.; Lingel, K.; Lohner, M.; Rankin, P.; Smith, J.G.; Alexander, J.P.; Bebek, C.; Berkelman, K.; Bloom, K.; Browder, T.E.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Crowcroft, D.S.; Drell, P.S.; Dumas, D.; Ehrlich, R.; Gaidarev, P.; Garcia-Sciveres, M.; Geiser, B.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Jones, C.D.; Jones, S.L.; Kandaswamy, J.; Katayama, N.; Kim, P.C.; Kreinick, D.L.; Ludwig, G.S.; Masui, J.; Mevissen, J.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Patterson, J.R.; Peterson, D.; Riley, D.; Salman, S.; Sapper, M.; Wuerthwein, F.; Avery, P.; Freyberger, A.; Rodriguez, J.; Yang, S.; Yelton, J.; Cinabro, D.; Liu, T.; Saulnier, M.; Wilson, R.; Yamamoto, H.; Bergfeld, T.; Eisenstein, B.I.; Gollin, G.; Ong, B.; Palmer, M.; Selen, M.; Thaler, J.J.; Edwards, K.W.; Ogg, M.; Bellerive, A.; Britton, D.I.; Hyatt, E.R.F.; MacFarlane, D.B.; Patel, P.M.; Spaan, B.; Sadoff, A.J.; Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Copty, N.; Davis, R.; Hancock, N.; Kelly, M.; Kotov, S.; Kravchenko, I.; Kwak, N.; Lam, H.; Kubota, Y.; Lattery, M.; Momayezi, M.; Nelson, J.K.; Patton, S.; Poling, R.; Savinov, V.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Ling, Z.; Mahmood, A.H.; O'Neill, J.J.; Severini, H.; Sun, C.R.; Wappler, F.; Crawford, G.; Daubenmier, C.M.; Fulton, R.; Fujino, D.; Gan, K.K.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Skovpen, Y.; Sung, M.; White, C.; Zoeller, M.M.; Butler, F.; Fu, X.; Nemati, B.; Ross, W.R.; Skubic, P.; Wood, M.; Bishai, M.; Fast, J.; Gerndt, E.; McIlwain, R.L.; Miao, T.; Miller, D.H.; Modesitt, M.; Payne, D.; Shibata, E.I.; Shipsey, I.P.J.; Wang, P.N.; Battle, M.; Ernst, J.; Gibbons, L.; Kwon, Y.

1994-01-01

An examination of leptons in Υ(4S) events tagged by reconstructed B meson decays yields semileptonic branching fractions of b - =(10.1±1.8±1.5)% for charged and b 0 =(10.9±0.7±1.1)% for neutral B mesons. This is the first measurement for charged B mesons. Assuming equality of the charged and neutral semileptonic widths, the ratio b - /b 0 =0.93±0.18±0.12 is equivalent to the ratio of lifetimes

Quasi-exotic open-flavor mesons

Energy Technology Data Exchange (ETDEWEB)

Hilger, T.; Krassnigg, A. [University of Graz, NAWI Graz, Institute of Physics, Graz (Austria)

2017-06-15

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{sup 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. (orig.)

A search for unconventional mesons

International Nuclear Information System (INIS)

Turnau, J.

1984-01-01

Selected problems of the fixed target meson spectroscopy connected with the issue of unconventional states glueballs, hybrides and four-quarks are discussed. The experimental basis of the dissertation consists of some results of the WA3 experiment performed by ACCMOR collaboration (Π - p→(3Π) - p, K - p→K - Π + Π - p, Π - p→K s o K s o n) and of the S136 experiment performed by CCM collaborations (Π - p↑→Π + Π - n, Π - p↑→K + K - n). Mesons with spin parities J PC = 0 -+ , 0 ++ , 1 ++ and 2 ++ are discussed from the point of view of the phenomenology of unconventional states. (author)

Computing K and D meson masses with N{sub f}=2+1+1 twisted mass lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Baron, Remi [CEA, Centre de Saclay, 91 - Gif-sur-Yvette (France). IRFU/Service de Physique Nucleaire; Blossier, Benoit; Boucaud, Philippe [Paris XI Univ., 91 - Orsay (FR). Lab. de Physique Theorique] (and others)

2010-05-15

We discuss the computation of the mass of the K and D mesons within the framework of N{sub f}=2+1+1 twisted mass lattice QCD from a technical point of view. These quantities are essential, already at the level of generating gauge configurations, being obvious candidates to tune the strange and charm quark masses to their physical values. In particular, we address the problems related to the twisted mass flavor and parity symmetry breaking, which arise when considering a non-degenerate (c,s) doublet. We propose and verify the consistency of three methods to extract the K and D meson masses in this framework. (orig.)

Few body problems in nuclear and particle physics

International Nuclear Information System (INIS)

Slobodrian, R.J.; Cujec, B.; Ramavataram, K.

1975-01-01

Nucleon-nucleon interactions at all energies, meson-nucleon and meson-deuteron interactions, nuclear bremsstrahlung, on-shell and off-shell interactions, final-state interactions, bound and scattering states, few-body forces, polarization phenomena, short range correlations, quasi-free scattering, composite hadron models, subnucleon structure, multiparticle and coherent production processes, break-up reactions, electrodisintegration, relativistic effects and future resources in nuclear and particle physics are discussed in relation to the state of few-body physics in 1974. (B.F.G.)

Igniting the Light Elements: The Los Alamos Thermonuclear Weapon Project, 1942-1952

Energy Technology Data Exchange (ETDEWEB)

Fitzpatrick, Anne C. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

1999-07-01

The American system of nuclear weapons research and development was conceived and developed not as a result of technological determinism, but by a number of individual architects who promoted the growth of this large technologically-based complex. While some of the technological artifacts of this system, such as the fission weapons used in World War II, have been the subject of many historical studies, their technical successors--fusion (or hydrogen) devices--are representative of the largely unstudied highly secret realms of nuclear weapons science and engineering. In the postwar period a small number of Los Alamos Scientific Laboratory's staff and affiliates were responsible for theoretical work on fusion weapons, yet the program was subject to both the provisions and constraints of the US Atomic Energy Commission, of which Los Alamos was a part. The Commission leadership's struggle to establish a mission for its network of laboratories, least of all to keep them operating, affected Los Alamos's leaders' decisions as to the course of weapons design and development projects. Adapting Thomas P. Hughes's ''large technological systems'' thesis, I focus on the technical, social, political, and human problems that nuclear weapons scientists faced while pursuing the thermonuclear project, demonstrating why the early American thermonuclear bomb project was an immensely complicated scientific and technological undertaking. I concentrate mainly on Los Alamos Scientific Laboratory's Theoretical, or T, Division, and its members' attempts to complete an accurate mathematical treatment of the ''Super''--the most difficult problem in physics in the postwar period--and other fusion weapon theories. Although tackling a theoretical problem, theoreticians had to address technical and engineering issues as well. I demonstrate the relative value and importance of H-bomb research over time in the postwar era to

Publications of Los Alamos research, 1985

International Nuclear Information System (INIS)

Sheridan, C.J.; McClary, W.J.; Rich, J.A.; Dussart, S.A.

1986-11-01

This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1985, including laboratory reports, papers released as non-laboratory reports, journal articles, books, conference papers, papers published in congrssional hearings, theses, and US patents

Phases, quantum interferences and effective vector meson masses in nuclei

Energy Technology Data Exchange (ETDEWEB)

Soyeur, M.

1996-12-31

We discuss the prospects for observing the mass of {rho}- and {omega}-mesons around nuclear matter density by studying their coherent photoproduction in nuclear targets and subsequent in-medium decay into e{sup +}e{sup -}pairs. The quantum interference of {rho} and {omega}-mesons in the e{sup +}e{sup -}channel and the interference between Bethe-Heitler pairs and dielectrons from vector meson decays are of particular interest. (author). 21 refs.

Study of the exclusive production of the Meson $ \\chi_{c0}$ in CMS / LHC Experiment

CERN Document Server

Da Silva Ramos Carneiro, Marilia

2013-01-01

We present a study of the central exclusive pro duction of the c 0 meson in pp collisions at p s = 7 TeV in the CMS detector at the LHC collider. The c 0 is a c c meson state with the same quantum numb ers as the Higgs b oson, so it's observation is a go o d opp ortunity to test the exclusive pro duction mechanism. We b egin with a brief description of the Standard Mo del, diraction physics and the exp erimental environment. The analysis was done using data collected in 2010 by CMS. We p erformed eciency studies using real data and a sample of simulated Monte Carlo events and a preliminary estimation of the cross section

Observation of a New Narrow Axial-Vector Meson alpha(1)(1420)

Czech Academy of Sciences Publication Activity Database

Adolph, C.; Akhunzyanov, R.; Alexeev, M.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Azevedo, C.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Birsa, R.; Bisplinghoff, J.; Bodlák, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Büchele, M.; Burtin, E.; Chang, W.-C.; Chiosso, M.; Choi, I.; Chung, S. U.; Cicuttin, A.; Crespo, M.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O.; Dhara, L.; Donskov, S. V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger jr., M.; Fischer, H.; Franco, C.; Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Gnesi, I.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Grosse-Perdekapm, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, E.; Hinterberger, F.; Horikawa, N.; d´Hose, N.; Hsieh, C.-Yu.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jarý, V.; Jörg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Y.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z. V.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.; Marchand, C.; Martin, A.; Marzec, J.; Matoušek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neyret, D.; Nikolaenko, V. I.; Nový, J.; Nowak, W. D.; Nunes, A.S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.-C.; Pereira, F.; Pešek, M.; Peshekhonov, D. V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Rocco, E.; Rossiyskaya, N. S.; Ryabchikov, D.; Rychter, A.; Samoylenko, V. D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schmeing, S.; Schmidt, K.; Schlüter, T.; Selyunin, A.; Schmieden, H.; Schönning, K.; Schopferer, S.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sozzi, F.; Srnka, Aleš; Stolarski, M.; Šulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Wallner, S.; Weisrock, T.; Wilfert, M.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

2015-01-01

Roč. 115, č. 8 (2015), 082001:1-6 ISSN 0031-9007 R&D Projects: GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : COMPASS * pion-nucleon scattering * hadron spectroscopy * light-meson spectrum * axial-vector mesons * exotic mesons Subject RIV: BH - Optics, Masers, Lasers Impact factor: 7.645, year: 2015

Limits on rare exclusive decays of B mesons

International Nuclear Information System (INIS)

Avery, P.; Besson, D.; Bowcock, T.; Giles, R.T.; Hassard, J.; Kinoshita, K.; Pipkin, F.M.; Wilson, R.; Wolinski, J.; Xiao, D.; Gentile, T.; Haas, P.; Hempstead, M.; Jensen, T.; Kagan, H.; Kass, R.; Behrends, S.; Guida, J.M.; Guida, J.A.; Morrow, F.; Poling, R.; Thorndike, E.H.; Tipton, P.; Alam, M.S.; Katayama, N.; Kim, I.J.; Sun, C.R.; Tanikella, V.; Bortoletto, D.; Chen, A.; Garren, L.; Goldberg, M.; Holmes, R.; Horwitz, N.; Jawahery, A.; Lubrano, P.; Moneti, G.C.; Sharma, V.; Csorna, S.E.; Mestayer, M.D.; Panvini, R.S.; Word, G.B.; Bean, A.; Bobbink, G.J.; Brock, I.C.; Engler, A.; Ferguson, T.; Kraemer, R.W.; Rippich, C.; Vogel, H.; Bebek, C.; Berkelman, K.; Blucher, E.; Cassel, D.G.; Copie, T.; DeSalvo, R.; DeWire, J.W.; Ehrlich, R.; Galik, R.S.; Gilchriese, M.G.D.; Gittelman, B.; Gray, S.W.; Halling, A.M.; Hartill, D.L.; Heltsley, B.K.; Holzner, S.; Ito, M.; Kandaswamy, J.; Kowalewski, R.; Kreinick, D.L.; Kubota, Y.; Mistry, N.B.; Mueller, J.; Namjoshi, R.; Nordberg, E.; Ogg, M.; Perticone, D.; Peterson, D.; Pisharody, M.; Read, K.; Riley, D.; Silverman, A.; Stone, S.; Yi Xia; Sadoff, A.J.

1987-01-01

We have set upper limits for rare exclusive decays of B mesons arising from higher order processes in the standard model of electroweak interactions. Such decays may occur via ''penguin diagrams'' in B decay. We also set an upper limit on a lepton-number-violating decay mode of the neutral B meson. (orig.)

Transportation of a 451 ton generator stator and a 234 ton generator rotor from Hartsville, TN, to Los Alamos, NM

International Nuclear Information System (INIS)

Boenig, H.J.; Rogers, J.D.; McLelland, G.R.; Pelts, C.T.

1989-01-01

A 1430 MVA steam turbine generator was acquired from a cancelled nuclear power plant in Tennessee to be used as the pulsed power and energy storage unit for the Confinement Physics Research Facility being built at Los Alamos, NM. The transportation from Hartsville, near Nashville, TN, to Los Alamos, NM, of the two largest single pieces of the generator, a 451 t stator and a 234 t rotor presented a special challenge. Details of the move, by barge from Hartsville to Catoosa, near Tulsa, OK, by rail from Catoosa to Lamy, near Santa Fe, NM, and by road from Lamy to Los Alamos are described. The greatest difficulty of the successful move was the crossing of the Rio Grande river on an existing reinforced concrete bridge. The two-lane wide road transporters for the stator and rotor were fitted with outriggers to provide a four-lane wide vehicle, thus spreading the load over the entire bridge width and meeting acceptable load distribution and bridge safety factors. 2 refs., 6 figs

Determining the meson-nucleus potential - on the way to mesic states

Energy Technology Data Exchange (ETDEWEB)

Metag, Volker, E-mail: volker.metag@exp2.physik.uni-giessen.de [Universität Giessen, II. Physikalisches Institut (Germany)

2015-08-15

Experimental approaches to determine the real and imaginary part of the meson-nucleus potential are described. The experiments have been performed with the Crystal Barrel/TAPS detector at the electron accelerator ELSA (Bonn) and the Crystal Ball/TAPS detector at MAMI (Mainz). Measuring the transparency ratio as well as the excitation function and momentum distribution for photo production of ω and η′ mesons, the imaginary part of the η′-nucleus potential is found to be smaller than the real part. In case of the ω meson the opposite is observed. This makes the η′ meson a good candidate for the search for meson-nucleus bound states while no resolved ω mesic states can be expected. The results are discussed and compared to theoretical predictions. An outlook on future experiments is given.

Intersections between particle and nuclear physics

International Nuclear Information System (INIS)

Van Oers, W.T.H.

1992-01-01

This report contains papers on High Energy Physics and Nuclear Physics research. Some of areas covered are: antiproton physics; detectors and instrumentation; accelerator facilities; hadron physics; mesons and lepton decays; physics with electrons and muons; physics with relativistic heavy ions; physics with spin; neutrinos and nonaccelerator physics. The individual paper have been indexed separately elsewhere

Latest results from meson photoproduction at ELSA and MAMI

Science.gov (United States)

Krusche, B.

2014-06-01

Photoproduction of mesons plays a key role for the investigation of the excitation spectrum of the nucleon and thus for our understanding of the strong interaction in the non-perturbative regime. In this contribution we discuss recent results from the experiments at the tagged photon beams of the electron accelerators ELSA in Bonn and MAMI in Mainz. They include the measurement of cross sections and (double) polarization observables for single meson production and production of meson pairs off free protons as well as of quasi-free nucleons bound in light nuclei (in particular the deuteron).

Muoproduction of J/ψ-mesons and the gluon distribution in nucleons

International Nuclear Information System (INIS)

Jong, Maarten de.

1991-01-01

The cross sections for production of J/ψ-mesons in muon-scattering at hydrogen and deuterium have been measured at a muon-energy of 280 GeV in order to extract from these the momentum distribution of gluons in the nucleon. These cross sections turned out to be equal for protons and neutrons within the experimental error. In the framework of the colour singlet model the gluon distribution has been determined from the cross section for the inelastic production of J/ψ mesons. At small gluon impulses the distribution obtained resembles a brems-strahlung spectrum. This distribution decreases, according to a simple description (counting rules) at larger impulses. The same model however underestimates the cross section for elastic production of J/ψ-mesons seriously. It is found that in inelastic production of J/ψ-mesons both helicities of the meson occur equally. Also a correlation has been observed between the scattering plane and the plane in which the J/ψ meson decays. The production of J/ψ-mesons and ψ'-mesons has been investigated in muon scattering at concrete at the same incoming energy. The measured ratio of their cross sections agrees with the colour singlet model but disagrees with the simplified description which characterizes the 'photon-gluon fusion model'. The possible nuclear-mass dependence of the cross section for J/ψ-meson production has been investigated in interactions of muons with tin and carbon at an energy of 280 GeV. This possible dependence turns out to be absent which means that on the basis of the colour singlet model the distributions of the gluons in the nucleon are equal in tin and carbon. (author). 103 refs.; 60 figs.; 19 tabs

A Phenomenological approach to rescattering of mesons and antibaryons in a heavy nucleus

International Nuclear Information System (INIS)

Camiz, P.; Ferrari, E.

1996-01-01

On the basis of a conceptual line developed in a previuos publication a phenomenological model for the description of rescattering of mesons and antibaryons in a heavy nucleus is presented. Together with the previous work, this treatment allows one to set up a model-independent routine that can be used in different physical situations. The approximations and the reliability of the approach are thoroughly discussed

Flaws found in Los Alamos safety procedures

Science.gov (United States)

Gwynne, Peter

2017-12-01

A US government panel on nuclear safety has discovered a series of safety issues at the Los Alamos National Laboratory, concluding that government oversight of the lab's emergency preparation has been ineffective.

submitter Time-dependent CP violation in charm mesons

CERN Document Server

Inguglia, Gianluca

CP violation is a well established phenomenon for B and K mesons, but for D0 mesons, bound states made up of a quark-antiquark pair containing a charm quark, a conclusive answer to the question whether there is CP vio- lation or not, has yet to be determined. I show here the phenomenology of time-dependent CP asymmetries in charm decays, and discuss the implica- tions of experimental tests aimed at the measurement of CP violation in the interference between mixing and decays of charm mesons, in particular when studying the decay channels D0 ! h+h (h = K; ). The decay channels considered can also be used to constrain quantities that are poorly measured or still to be investigated, such as MIX and c;eff , provided that the e ects of penguin pollution are ignored. I considered correlated production of D0 mesons at the SuperB experiment and its planned asymmetric run at the charm threshold and performed a study of simulated events, nding that a boost factor = 0:28 would not be su cient to produce competitive re- ...

Quasi two-body decays of D0 meson

International Nuclear Information System (INIS)

Terasaki, K.; Oneda, S.

1985-08-01

Quasi two-body decays of D 0 -meson are studied from an algebraic approach, using a hard meson extrapolation. In this innovation of old current algebra with new perspective, a reasonable unified description of K sub(S) → 2π and D 0 → K-barπ decays has been obtained previously, keeping only the contribution of ground state mesons to the now surviving surface term. In this paper, it is shown that quasi two-body decays can also be accomodated reasonably well in the same scheme. A distinctive feature of our result is that GAMMA(D 0 → phi K-bar 0 ) is sizable, while D 0 → rho 0 K-bar 0 is relatively suppressed. (author)

Los Alamos contribution to target diagnostics on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Mack, J.M.; Baker, D.A.; Caldwell, S.E. [and others

1994-07-01

The National Ignition Facility (NIF) will have a large suite of sophisticated target diagnostics. This will allow thoroughly diagnosed experiments to be performed both at the ignition and pre-ignition levels. As part of the national effort Los Alamos National Laboratory will design, construct and implement a number of diagnostics for the NIF. This paper describes Los Alamos contributions to the ``phase I diagnostics.`` Phase I represents the most fundamental and basic measurement systems that will form the core for most work on the NIF. The Los Alamos effort falls into four categories: moderate to hard X-ray (time resolved imaging neutron spectroscopy- primarily with neutron time of flight devices; burn diagnostics utilizing gamma ray measurements; testing measurement concepts on the TRIDENT laser system at Los Alamos. Because of the high blast, debris and radiation environment, the design of high resolution X-ray imaging systems present significant challenges. Systems with close target proximity require special protection and methods for such protection is described. The system design specifications based on expected target performance parameters is also described. Diagnosis of nuclear yield and burn will be crucial to the NIF operation. Nuclear reaction diagnosis utilizing both neutron and gamma ray detection is discussed. The Los Alamos TRIDENT laser system will be used extensively for the development of new measurement concepts and diagnostic instrumentation. Some its potential roles in the development of diagnostics for NIF are given.

Los Alamos contribution to target diagnostics on the National Ignition Facility

International Nuclear Information System (INIS)

Mack, J.M.; Baker, D.A.; Caldwell, S.E.

1994-01-01

The National Ignition Facility (NIF) will have a large suite of sophisticated target diagnostics. This will allow thoroughly diagnosed experiments to be performed both at the ignition and pre-ignition levels. As part of the national effort Los Alamos National Laboratory will design, construct and implement a number of diagnostics for the NIF. This paper describes Los Alamos contributions to the ''phase I diagnostics.'' Phase I represents the most fundamental and basic measurement systems that will form the core for most work on the NIF. The Los Alamos effort falls into four categories: moderate to hard X-ray (time resolved imaging neutron spectroscopy- primarily with neutron time of flight devices; burn diagnostics utilizing gamma ray measurements; testing measurement concepts on the TRIDENT laser system at Los Alamos. Because of the high blast, debris and radiation environment, the design of high resolution X-ray imaging systems present significant challenges. Systems with close target proximity require special protection and methods for such protection is described. The system design specifications based on expected target performance parameters is also described. Diagnosis of nuclear yield and burn will be crucial to the NIF operation. Nuclear reaction diagnosis utilizing both neutron and gamma ray detection is discussed. The Los Alamos TRIDENT laser system will be used extensively for the development of new measurement concepts and diagnostic instrumentation. Some its potential roles in the development of diagnostics for NIF are given

Inclusive weak decays of charmed mesons

International Nuclear Information System (INIS)

Matthews, C.G.

1993-01-01

Inclusive analysis provide a different insight into the understanding of weak decay physics. This thesis experimentally determines inclusive decay predictions of charmed D mesons. Exclusive decay predictions are also used from a variety of theoretical models to make predictions about inclusive properties. Both experimental and theoretical realms benefit from the new techniques presented in this thesis. Inclusive properties derived are the multiplicity distributions, average multiplicities and inclusive branching ratios of charged particles, charged and neutral kaons, and charged pions. The center-of-mass momentum spectra of charged and neutral kaons are also obtained. Additionally, in the theoretical realm only, the inclusive properties of neutral pions, and the center-of-mass momentum spectra of charged and neutral pions are determined. The experimental analysis, which uses data from the mark II experiment at the Stanford Linear Accelerator Center, employs an unfold technique utilizing fold matrices to obtain the charged particle and kaon properties. A new enhanced unfold technique involving fold tensors obtains the first-ever results for the inclusive charged pion properties. The average strange quark contents and the average charged lepton multiplicities of the D + , D 0 and D + 8 are also presented. In the theoretical analysis, the exclusive decay mode predictions from the factorization model for Bauer, Stech and Wirbel; the quark diagram scheme of Chau and Cheng; and the QCD sum rules model of Block and Shifman are processed to determine inclusive predictions will lead to a better understanding of the model. The thesis also derives inclusive predictions from the D meson exclusive branching ratios compiled by the Particle Data Group

Chiral symmetry breaking and the spin content of the ρ and ρ' mesons

International Nuclear Information System (INIS)

Glozman, L.Ya.; Lang, C.B.; Limmer, M.

2011-01-01

Using interpolators with different SU(2) L xSU(2) R transformation properties we study the chiral symmetry and spin contents of the ρ and ρ ' mesons in lattice simulations with dynamical quarks. A ratio of couplings of the q-bar γ i τq and q-bar σ 0i τq interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of ∼1 fm. In the ground state ρ meson the chiral symmetry is strongly broken with comparable contributions of both the (0,1)+(1,0) and (1/2,1/2) b chiral representations with the former being the leading contribution. In contrast, in the ρ ' meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1/2,1/2) b . Using a unitary transformation from the chiral basis to the 2S+1 L J basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The ρ meson is practically a 3 S 1 state with no obvious trace of a 'spin crisis'. The ρ ' meson has a sizeable contribution of the 3 D 1 wave, which implies that the ρ ' meson cannot be considered as a pure radial excitation of the ρ meson.

Electro- and chromomagnetism in the charm meson spectrum

CERN Document Server

Fritzsch, Harald

1977-01-01

How the D and F meson spectrum is influenced by the chromomagnetic and electromagnetic hyperfine interaction is discussed. In particular a relation between the hyperfine splitting of charmed mesons and the magnetic moments of the baryons is derived. It is found that M(F/sub + /*)-M(F/sub +/) approximately=100+or-8 MeV. (12 refs).

Recent trends in the mesonic description of nuclei

International Nuclear Information System (INIS)

Delorme, J.

1985-07-01

A survey is given of some recent developments in the domain of meson induced phenomena in nuclei. The manifestations of mesonic degrees of freedom are considered in the context of exchange currents as well as that of effective interactions. The significance of past successes is reexamined in the light of recent progress towards a QCD based nuclear theory

First measurement of the B S meson mass

Science.gov (United States)

Buskulic, D.; De Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Blucher, E.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Hagelberg, R.; Harvey, J.; Haywood, S.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Lohse, T.; Maggi, M.; Markou, C.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miotto, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Pusztaszeri, J.-F.; Ranjard, F.; Redlinger, G.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Veenhof, R.; Wachsmuth, H.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Lannutti, J.; Levinthal, D.; Sawyer, L.; Wasserbaech, S.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Tomalin, I. R.; Wright, A. G.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Steeg, F.; Walther, S. M.; Wanke, R.; Wolf, B.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jacobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; St. Denis, R.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jaffe, D. E.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Carter, J. M.; Gao, Y.; Green, M. G.; March, P. V.; Mir, Ll. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L. R.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Cinabro, D.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; LeClaire, B. W.; Lishka, C.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Sharma, V.; Shi, Z. H.; Walsh, A. M.; Weber, F. V.; Wu, Sau Lan; Wu, X.; Zheng, M.; Zobernig, G.

1993-07-01

In a sample of about 1.1 million hadronic Z decays recorded with the ALEPH detector during the 1990-1992 running of LEP, two unambiguous B S meson candidates were observed. From these events the mass of the B S meson has been measured to be 5.3686 ± 0.0056 (stat.) ± 0.0015 (syst.) GeV.

Production of φ-Mesons in anti NN-Annihilation

International Nuclear Information System (INIS)

Sapozhnikov, M.G.

1994-01-01

Recent results from the experiments on the φ-meson production in the annihilation of stopped antiprotons have demonstrated a significant (by a factor of 30-50) violation of the OZI rule. Experimental information on the φ-meson production is discussed and possible theoretical explanations of the strong OZI rule violation are reviewed. 37 refs., 4 figs., 2 tabs

Perspectives of Scalar- and Vector- Meson Production in Hadron-Nucleus Reactions