Clinton P. Anderson Meson Physics Facility and its operational safety program
International Nuclear Information System (INIS)
Putnam, T.M.
1975-01-01
The Clinton P. Anderson Meson Physics Facility (LAMPF) at the Los Alamos Scientific Laboratory consists of/ (1) a medium-energy, high-intensity linear proton accelerator; (2) experimental areas designed to support a multidisciplined program of research and practical applications; and (3) support facilities for accelerator operations and the experimental program. The high-intensity primary and secondary beams at LAMPF and the varied research program create many interesting and challenging problems for the Health Physics staff. A brief overview of LAMPF is presented, and the Operational Safety Program is discussed, with emphasis on the radiological safety and health physics aspects
International Nuclear Information System (INIS)
1987-09-01
This document constitutes the (1987 to 1988) progress report for the ongoing medium energy nuclear physics research program supported by the US Department of Energy with the University of Texas at Austin. A major part of the work has been and will continue to be associated with research done at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF) using the High Resolution Spectrometer (HRS), the External Proton Beam (EPB), and the new Neutron Time of Flight Facility (NTOF). Other research is done at the Fermi National Accelerator Laboratory (FNAL). The research focuses on (1) providing proton + nucleus data which test nonrelativistic and relativistic models of the medium energy proton + nucleus interaction, (2) providing (p,p) and (p,n) data which are to be analyzed to provide new nuclear structure information (both ground state and excited state), (3) providing nucleon + nucleon data to aid in the systematic study of the fundamental nucleon-nucleon interaction, (4) developing and improving the proton + nucleus theoretical models themselves, and (5) initiating new experimental programs whose goals are to search for new phenomena in nuclear physics. 182 refs., 71 figs., 5 tabs
Operational health physics at the Los Alamos meson physics proton accelerator
International Nuclear Information System (INIS)
Engelke, M.J.
1975-01-01
The operational health physics practices and procedures at the Clinton P. Anderson Los Alamos Meson Physics Facility (LAMPF), a medium energy, high intensity proton accelerator are reviewed. The operational philosophy used for the control of personnel exposures and radioactive materials is discussed. A particular operation involving the removal of a radioactive beam stop reading in excess of 1000 R/h is described
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
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
International Nuclear Information System (INIS)
Green, W.V.; Sommer, W.F.; Coulter, C.A.
1979-01-01
Experience is reported with the first in-situ cyclic-stress irradiation at LAMPF. A proton beam ion current of 3 to 6 μA of 800 MeV protons was utilized for 24 days irradiation. Radiation damage effects of 800 MeV protons incident on a 1-cm thick Cu target were calculated using the nucleon-meson transport code to determine the nuclear reactions produced by the protons, the theory of Lindhard to evaluate the resultant damage energy deposited in the target. These calculations have been extended to Al. Damage effects were nearly uniform through a 1-cm target thickness, and the results obtained can be expressed in cross section form. The calculation yielded a damage energy cross section of about 63 barn-keV, a nuclear transmutation cross section of 0.44 barns, and indicated copious hydrogen, helium, and neutron production. Analysis of the effect of dislocation vibration on the efficiency of a dislocation line as a sink for point defects predicted that dislocation vibration should suppress void growth. The effect results from the fact that the dislocation will sweep up vacancies, which diffuse less rapidly than interstitials. The growth rate of voids in Al under simultaneous proton irradiation and cyclic stressing are compared to that of samples irradiated at the same time but without any stressing. The samples are placed one behind the other along the proton path so that identical irradiation histories can be achieved. The temperature of the samples is controlled, known and uniform. The initial preirradiation state is a prestrained state of a few hundred stress cycles. The samples are irradiated without stress through the incubation period for void nucleation before the cyclic stress is applied
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.
New physics effects from meson decays
Indian Academy of Sciences (India)
It has long been established that the -meson system (both charged and neutral) may be the ideal place to look for indirect effects of physics, both CP-conserving and CP-violating, beyond the Standard Model (BSM) [1]. However, before one proceeds, one must remember that the theoretical uncertainties are still significant, ...
Status of the Clinton P. Anderson Meson Physics Facility (LAMPF)
International Nuclear Information System (INIS)
Jain, M.; Rosen, L.
1975-01-01
A brief history and a description of the LAMPF Linac is given, followed by a discussion of the experimental areas, some selected experimental results, and some practical applications. Differential cross section data for n-p charge exchange scattering near 640 MeV are compared with data taken on other machines, and data on pion scattering are presented. The application of negative pions to the treatment of cancer is discussed
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)
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.
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.)
International Nuclear Information System (INIS)
Sharirli, M.; Butner, J.M.; Rand, J.L.; Macek, R.J.; McKinney, S.J.; Roush, M.L.
1992-01-01
This paper presents results from a Los Alamos National Laboratory Engineering and Safety Analysis Group assessment of the worse-case design-basis accident associated with the Clinton P. Anderson Meson Physics Facility (LAMPF)/Weapons Neutron Research (WNR) Facility. The primary goal of the analysis was to quantify the accident sequences that result in personnel radiation exposure in the WNR Experimental Hall following the worst-case design-basis accident, a complete spill of the LAMPF accelerator 1L beam. This study also provides information regarding the roles of hardware systems and operators in these sequences, and insights regarding the areas where improvements can increase facility-operation safety. Results also include confidence ranges to incorporate combined effects of uncertainties in probability estimates and importance measures to determine how variations in individual events affect the frequencies in accident sequences
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.
Progress at LAMPF: Clinton P. Anderson Meson Physics Facility. Progress report, July-December 1980
Energy Technology Data Exchange (ETDEWEB)
Allred, J.C. (ed.)
1981-03-01
Progress at LAMPF is the semiannual progress report of the MP Division of the Los Alamos National Laboratory. The report also includes brief reports on research done at LAMPF by researchers from other institutions and Los Alamos divisions.
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
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, 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
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
Seismic vulnerability study Los Alamos Meson Physics Facility (LAMPF)
International Nuclear Information System (INIS)
Salmon, M.; Goen, L.K.
1995-01-01
The Los Alamos Meson Physics Facility (LAMPF), located at TA-53 of Los Alamos National Laboratory (LANL), features an 800 MeV proton accelerator used for nuclear physics and materials science research. As part of the implementation of DOE Order 5480.25 and in preparation for DOE Order 5480.28, a seismic vulnerability study of the structures, systems, and components (SSCs) supporting the beam line from the accelerator building through to the ends of die various beam stops at LAMPF has been performed. The study was accomplished using the SQUG GIP methodology to assess the capability of the various SSCs to resist an evaluation basis earthquake. The evaluation basis earthquake was selected from site specific seismic hazard studies. The goals for the study were as follows: (1) identify SSCs which are vulnerable to seismic loads; and (2) ensure that those SSCs screened during die evaluation met the performance goals required for DOE Order 5480.28. The first goal was obtained by applying the SQUG GIP methodology to those SSCS represented in the experience data base. For those SSCs not represented in the data base, information was gathered and a significant amount of engineering judgment applied to determine whether to screen the SSC or to classify it as an outlier. To assure the performance goals required by DOE Order 5480.28 are met, modifications to the SQUG GIP methodology proposed by Salmon and Kennedy were used. The results of this study ire presented in this paper
Symmetry breaking and physical properties of the bosonic single-impurity Anderson model
Warnes, J. H.; Miranda, E.
2012-10-01
We show how exact diagonalization of small clusters can be used as a fast and reliable impurity solver by determining the phase diagram and physical properties of the bosonic single-impurity Anderson model. This is specially important for applications which require the solution of a large number of different single-impurity problems, such as the bosonic dynamical mean field theory of disordered systems. In particular, we investigate the connection between spontaneous global gauge symmetry breaking and the occurrence of Bose-Einstein condensation (BEC). We show how BEC is accurately signaled by the appearance of broken symmetry, even when a fairly modest number of states is retained. The occurrence of symmetry breaking can be detected both by adding a small conjugate field or, as in generic quantum critical points, by the divergence of the associated phase susceptibility. Our results show excellent agreement with the considerably more demanding numerical renormalization group (NRG) method. We also investigate the mean impurity occupancy and its fluctuations, identifying an asymmetry in their critical behavior across the quantum phase transitions between BEC and `Mott' phases.
The ideal mixing departure in vector meson physics
International Nuclear Information System (INIS)
Epele, L.; Fanchiotti, H.; Grunfeld, A.G.
2003-01-01
In this work we study the departure from the ideal φ-ω mixing angle within the framework of the Nambu-Jona-Lasinio model. In this context we show that the flavor symmetry breaking is unable to produce the shifting of the ideal mixing. We found that a nonet symmetry breaking in the neutral vector sector is necessary to regulate the non-strange content of the φ meson. The phenomenology is well described by our proposal. (orig.)
A calculation of the physical mass of sigma meson
Indian Academy of Sciences (India)
where the coefficient 3/2 for the pion loop comes from the three isospin states and the permutation symmetry factor [29]. We will work in the σ-meson rest frame, for which kμ. = (k0,0). Carrying out the integration of Σ(k) with respect to q0 by using the Cauchy residue theorem, and integrating in the q0 complex plane, we obtain.
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
Los Alamos Meson Physics Facility high-resolution-spectrometer dipole magnets: a summary report
International Nuclear Information System (INIS)
Kozlowski, T.; Madland, D.G.; Rolfe, R.; Smith, W.E.; Spencer, J.E.; Tanaka, N.; Thiessen, H.A.; Varghese, P.; Wilkerson, L.C.
1982-12-01
This report explains the design, fabrication, measurement, optimization, and installation of two 122 metric ton electromagnets for the High Resolution Proton Spectrometer at the Los Alamos Meson Physics Facility. These two magnets are the principal components of the proton spectrometer, which has an energy resolution of less than or equal to 10 - 4 FWHM. Many technical problems occurred during fabrication, measurement, and optimization, and the majority have been successfully solved. We hope that this report will help others planning similar projects
Noninterceptive beam energy measurements in line D of the Los Alamos Meson Physics Facility
International Nuclear Information System (INIS)
Gilpatrick, J.D.; Carter, H.; Plum, M.; Power, J.F.; Rose, C.R.; Shurter, R.B.
1995-01-01
Several members of the Accelerator and Operations Technology (AOT) division beam-diagnostics team performed time-of-flight (TOF) beam-energy measurements in line D of the Los Alamos Meson Physics Facility (LAMPF) using developmental beam time. These measurements provided information for a final design of an on-line beam energy measurement. The following paper discusses these measurements and how they apply to the final beam energy measurement design
Proceedings of the LAMPF workshop on photon and neutral meson physics at intermediate energies
International Nuclear Information System (INIS)
Baer, H.W.; Crannell, H.; Peterson, R.J.
1987-12-01
This volume contains the Proceedings of the Workshop on ''Photon and Neutral-Meson, Physics at Intermediate Energies,'' held at Los Alamos, New Mexico, January 7 to 9, 1987. The purpose of this workshop was to bring together scientists working in the areas of electromagnetic, heavy-ion, and light hadron physics to discuss both the physics that could be addressed and potential capabilities of new, large intermediate-energy photon detectors. Based on the papers contained in these proceedings, it appears clear that there are a number of important areas that could be addressed with a much higher resolution neutral meson detector. It is also clear that the technical capability for building a neutral meson detector for energies up to 4 GeV with solid angle of approximately 10 mrs and resolution of a few hundred keV now exists. It also appears entirely reasonable to construct such a detector to be easily transportable so that it would become a national facility, available for use at a number of different laboratories. From the many interesting papers presented and from the broad representation of physicists from laboratories in Asia, Canada, Europe, Japan, and the United States, there appears to be a strong case for proceeding with the construction of such a detector
Present and future neutrino physics research at the Los Alamos Meson Physics Facility
International Nuclear Information System (INIS)
Sanders, G.H.
1988-01-01
The Los Alamos Meson Physics Facility is currently the site of two neutrino experiments. A measurement of elastic scattering of electron-neutrinos on electrons is providing confirmation of the destructive interference between the weak neutral and charged currents predicted in the standard electroweak theory. A search for the appearance of /bar/ν//sub e/ is being carried out at the LAMPF beam stop, as well. The status of this experiment is described. A major new initiative is being undertaken to measure neutrino-electron scattering in a large water Cerenkov detector. This meaurement will be precise enough to provide, in combination with the meaurements to be performed at the new generation of high-energy electron-positron colliers, the first experimental study of the standard electrowak theory at the level of one-loop radiative corrections. The detector will also be a vehicle for neutrino-oscillation searches, measurement of neutrinos from supernovae, and other fundamental physics. The apparatus will consist of a neutrino production target and shield surrounded by a water Cerenkov detector. The fiducial volume of water will be approximately 7000 tons, viewed by approximately 13000 20 cm diameter photomultiplier tubes. 11 refs., 6 figs
Phil Anderson and Gauge Symmetry Breaking
Witten, Edward
In this article, I describe the celebrated paper that Phil Anderson wrote in 1962 with early contributions to the idea of gauge symmetry breaking in particle physics. To set the stage, I describe the work of Julian Schwinger to which Anderson was responding, and also some of Anderson's own work on superconductivity that provided part of the context. After describing Anderson's work I describe the later work of others, leading to the modern understanding of gauge symmetry breaking in weak interactions...
International Nuclear Information System (INIS)
Huneycutt, S.E.
1996-05-01
The purpose of this study was to determine the effects of the addition of an air scrubber to an already existing delay line and whether it would scrub 11 CO 2 . There were three main objectives of this study. The first objective was to determine the scrubbing efficiency of the scrubber. The scrubbing efficiency was then used to predict the dose rates in the scrubber area and compare those values with measurements from radiological surveys. The third objective was to determine if the shield blocks were effective in reducing the dose rates in the scrubber area. The activities were measured before and during scrubber operation and this information was used to calculate the scrubbing efficiency and the efficiency of 11 CO 2 removal was determined to be around 50%. Microshield was then used to predict dose rates and compared those values with measurements from radiological surveys. This was also used to determine the that the shield blocks around the scrubber were effective in reducing the dose rates from the radiation field produced by the radionuclides in the scrubber
Ion-chamber-based loss monitor system for the Los Alamos Meson Physics Facility
International Nuclear Information System (INIS)
Plum, M.A.; Brown, D.; Browman, A.; Macek, R.J.
1995-01-01
A new loss monitor system has been designed and installed at the Los Alamos Meson Physics Facility (LAMPF). The detectors are ion chambers filled with N 2 gas. The electronics modules have a threshold range of 1:100, and they can resolve changes in beam loss of about 2% of the threshold settings. They can generate a trip signal in 2 μs if the beam loss is large enough; if the response time of the Fast Protect System is included the beam will be shut off in about 37 μs
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.
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
Physics and detector simulation studies of B-meson decays in ATLAS
Damet, J
2001-01-01
This thesis has two objectives; the first is to study the phenomenology of heavy quarks in high energy proton- proton collisions at the Large Hadron Collider (LHC) at the European Laboratory for Particle Physics (CERN). The second objective is to estimate the performance for B- physics analysis of the Inner Tracking Detector in the ATLAS experimental set-up at the LHC. Phenomenological models of B-meson production-asymmetry and prompt J/ψ production are examined to investigate, and better understand, the different non perturbative QCD models and their description of potential sources of background in CP violation measurements. A Monte Carlo evaluation is made of the precision that can be reached in measurements of CP-violation in the B0d→J/yK0 s decay channel as well as of the possibilities of ATLAS to detect physics beyond the Standard Model in the B+ → K+K +π− decay channel. It is shown that after three years of running at low luminosity (30 fb−1) with...
Renormalization-group evolution of new physics contributions to (semi)leptonic meson decays
González-Alonso, Martín; Martin Camalich, Jorge; Mimouni, Kin
2017-09-01
We study the renormalization group evolution (RGE) of new physics contributions to (semi)leptonic charged-current meson decays, focusing on operators involving a chirality flip at the quark level. We calculate their evolution under electroweak and electromagnetic interactions, including also the three-loop QCD running and provide numerical formulas that allow us to connect the values of the corresponding Wilson coefficients from scales at the TeV to the low-energy scales. The large mixing of the tensor operator into the (pseudo)scalar ones has important phenomenological implications, such as the RGE of new physics bounds obtained from light quark decays or in b → cℓν transitions. For instance, we study scenarios involving tensor effective operators, which have been proposed in the literature to address the B-decay anomalies, most notably those concerning the R D (*) ratios. We conclude that the loop effects are important and should be taken into account in the analysis of these processes, especially if the operators are generated at an energy scale of ∼1 TeV or higher.
50 Years of Anderson Localization
Abrahams, Elihu
2010-01-01
In his groundbreaking paper Absence of diffusion in certain random lattices (1958), Philip W. Anderson originated, described and developed the physical principles underlying the phenomenon of the localization of quantum objects due to disorder. Anderson's 1977 Nobel Prize citation featured that paper, which was fundamental for many subsequent developments in condensed matter theory and technical applications. After more than a half century, the subject continues to be of fundamental importance. In particular, in the last 25 years, the phenomenon of localization has proved to be crucial for the
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
International Nuclear Information System (INIS)
Bowen, B.M.; Olsen, W.A.; Chen, Ili; Van Etten, D.M.
1987-11-01
An array of three portable, pressurized ionization chambers (PICs) continued to measure external radiation levels during 1985 caused by radionuclides emitted from the Los Alamos Meson Physics Facility (LAMPF). A Gaussian-type atmospheric dispersion model, using onsite meteorological and stack release data, was tested during this study. A more complex finite model, which takes into account the contribution of radiation at a receptor from different locations of the passing plume, was also tested. Monitoring results indicate that, as in 1984, a persistent wind up the Rio Grande Valley during the evening and early morning hours is largely responsible for causing the highest external radiation levels to occur to the northeast and north-northeast of LAMPF. However, because of increased turbulent mixing during the day, external radiation levels are generally much less during the day than at night. External radiation levels during 1985 show approximately a 75% reduction over 1984 levels. This resulted from a similar percentage reduction in LAMPF emissions caused by newly implemented emission controls. Comparison of predicted and measured daily external radiation levels indicates a high degree of correlation. The model also gives accurate estimates of measured concentrations over longer time periods. Comparison of predicted and measured hourly values indicates that the model generally tends to overpredict during the day and underpredict at night. 9 refs., 14 figs., 13 tabs
International Nuclear Information System (INIS)
Hey, A.J.G.; Morgan, D.
1977-04-01
Following is an abbreviated list of section headings: meson spectrum - classification schemes introduced and compared to experiment (quark models, dual models); symmetries of hadrons - theories and models for classifying mesons and their transitions (including - current algebra, PCAC and chiral symmetry, infinite momentum and SU(6)sub(W), the Melosh transformation and the SU(6)sub(W) structure of transitions); meson decays (hadronic decays and the quark model, electromagnetic decays, weak decays); experimental study of meson resonances - special problems and analysis and interpretation (including - three-body phase shift analysis - status of the A 1 , Q and related effects, exchange mechanism in dimeson production - meson-meson scattering, scalar mesons); the mesons (including - theoretical models and especially charm). (U.K)
International Nuclear Information System (INIS)
Tolpin, A.E.
1992-01-01
A new approach toward understanding the heavy-fermion systems (HFS) within a framework of the almost-degenerate lattice Anderson Hamiltonian in the Kondo regime is proposed. In the coherent low-temperature regime, operators in the effective Hamiltonian are found to belong to an SU(2J + 3) dynamical algebra. A canonical transformation is employed to decouple the quasiparticle branches, thereby setting up the decoupling equation. It is found that this decoupling equation has a solution of the symmetry-altering type. The thermodynamic response functions and other quantities are calculated for this new state. This solution is a consequence of the degeneracy of the uncoupled f-orbitals. It is characterized by the interatomic hopping of f-electrons, which produces the spin-delocalization regime and with the renormalized f-level pinned close to the Fermi level. This is also found to be the source of the apparent spin-compensation regime, which is accompanied by large enhancement of the thermodynamic response functions. In addition, the calculated phase coherence length is found to be much greater than a lattice constant, thereby showing a many-body character of this new state. It is believed that this new state provides an accurate description of the heavy-fermion state at low temperatures. The stability conditions for the new regime are also discussed
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
Research in experimental nuclear physics: Progress report, 1 April 1978 to 31 March 1979
International Nuclear Information System (INIS)
1979-01-01
This report summarizes the work carried out at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF). The research activities involved experiments done with the High Resolution Spectrometer (HRS), the Energetic Pion Channel and Spectrometer (EPICS), and the External Proton Beam (EPB). A list of publications during the contract period and personnel is included. 33 refs., 36 figs., 1 tab
Indian Academy of Sciences (India)
Home; Fellowship. Fellow Profile. Elected: 1978 Honorary. Anderson, Prof. John Stuart. Date of birth: 9 January 1908. Date of death: 25 December 1990. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held ...
Anderson, Prof. Basil Williams
Indian Academy of Sciences (India)
Home; Fellowship. Fellow Profile. Elected: 1964 Honorary. Anderson, Prof. Basil Williams. Date of birth: 3 July 1901. Date of death: 24 February 1984. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held ...
Indian Academy of Sciences (India)
Home; Fellowship. Fellow Profile. Elected: 1978 Honorary. Anderson, Prof. John Stuart. Date of birth: 9 January 1908. Date of death: 25 December 1990. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India ...
Anderson, Prof. Basil Williams
Indian Academy of Sciences (India)
Home; Fellowship. Fellow Profile. Elected: 1964 Honorary. Anderson, Prof. Basil Williams. Date of birth: 3 July 1901. Date of death: 24 February 1984. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on ...
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
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
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.
Kettemann, S.; Mucciolo, E. R.; Varga, I.; Slevin, K.
2012-03-01
Dilute magnetic impurities in a disordered Fermi liquid are considered close to the Anderson metal-insulator transition (AMIT). Critical power-law correlations between electron wave functions at different energies in the vicinity of the AMIT result in the formation of pseudogaps of the local density of states. Magnetic impurities can remain unscreened at such sites. We determine the density of the resulting free magnetic moments in the zero-temperature limit. While it is finite on the insulating side of the AMIT, it vanishes at the AMIT, and decays with a power law as function of the distance to the AMIT. Since the fluctuating spins of these free magnetic moments break the time-reversal symmetry of the conduction electrons, we find a shift of the AMIT, and the appearance of a semimetal phase. The distribution function of the Kondo temperature TK is derived at the AMIT, in the metallic phase, and in the insulator phase. This allows us to find the quantum phase diagram in an external magnetic field B and at finite temperature T. We calculate the resulting magnetic susceptibility, the specific heat, and the spin relaxation rate as a function of temperature. We find a phase diagram with finite-temperature transitions among insulator, critical semimetal, and metal phases. These new types of phase transitions are caused by the interplay between Kondo screening and Anderson localization, with the latter being shifted by the appearance of the temperature-dependent spin-flip scattering rate. Accordingly, we name them Kondo-Anderson transitions.
International Nuclear Information System (INIS)
Bowen, B.M.; Chen, A.I.; Olsen, W.A.; Van Etten, D.M.
1985-01-01
Short-term gamma-absorbed doses were measured by one high-pressure ionization chamber (HPIC) at an azimuth of 12 0 from the Los Alamos Meson Physics Facility (LAMPF) stack during the January 1 through February 8 operating cycle. Two HPICs were in the field during the September 8 through December 31 operating cycle, one north and the other north-northeast of the LAMPF stack, but they did not provide reliable data. Meteorological data were also measured at both East Gate and LAMPF. Airborne emission data were taken at the stack. Daily model predictions, based on the integration of modeled 15-min periods, were made for the first LAMPF operating cycle and were compared with the measured data. A comparison of the predicted and measured daily gamma doses due to LAMPF emissions is presented. There is very good correlation between measured and predicted values. During 39-day operating cycles, the model predicted an absorbed dose of 10.3 mrad compared with the 8.8 mrad that was measured, an overprediction of 17%
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)
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], January-December 1987
International Nuclear Information System (INIS)
Poelakker, K.
1988-09-01
This report is the annual progress report of MP Division of the Los Alamos National Laboratory. Included are brief reports on research done at LAMPF by researchers from other institutions and other Los Alamos Divisions. These reports included the following topics: Nuclear and particle physics; Atomic and molecular physics; Materials science; Radiation-effects studies; Biomedical research and instrumentation; Nuclear chemistry; Radioisotope production and accelerator facilities development and operation
MesonNet 2014 International Workshop : Mini-proceedings
Kupsc, Andrzej; Masjuan, Pere
2014-01-01
The MesonNet International Workshop was held in the Laboratori Nazionali di Frascati from September the 29th to October the 1st, 2014, being the concluding meeting of the MesonNet research network within EU HadronPhysics3 project. MesonNet is a research network focused on light meson physics gathering experimentalist and theoreticians from Europe and abroad. An overview of the research projects related to the scope of the network is presented in these mini-proceedings.
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
Non-leptonic B meson decays as a probe of new physics
Energy Technology Data Exchange (ETDEWEB)
Jung, Martin
2009-07-17
Despite the tremendous success of the Standard Model, the arguments for the necessity of an extension are compelling. The corresponding energy scale is expected to be O(TeV); it should lead therefore to visible effects in high-precision flavour observables. While no conclusive effect is seen there up to now, the data reveal certain puzzles when compared to Standard Model expectations based on a global fit of the CKM unitarity triangle and general theoretical expectations. The discussion of these tensions in the channels B{yields}J/{psi}K, B{yields}{phi}K, and B{yields}{pi}K, and the deduced constraints for New Physics operators of the class b{yields}s anti qq form the first project discussed in this thesis. On the other hand, hadronic uncertainties within the Standard Model are still not well understood. Therefore the opposite assumption of large hadronic Standard Model effects in B{yields}J/{psi}K is made in the second project, allowing in addition for a New Physics phase in B- anti B mixing. Finally, the necessity of reliable SM predictions is addressed by developing a framework for the model-independent inclusion of corrections to U-spin symmetry predictions. (orig.)
Light Meson Distribution Amplitudes
Arthur, R.; Brommel, D.; Donnellan, M.A.; Flynn, J.M.; Juttner, A.; de Lima, H.Pedroso; Rae, T.D.; Sachrajda, C.T.; Samways, B.
2010-01-01
We calculated the first two moments of the light-cone distribution amplitudes for the pseudoscalar mesons ($\\pi$ and $K$) and the longitudinally polarised vector mesons ($\\rho$, $K^*$ and $\\phi$) as part of the UKQCD and RBC collaborations' $N_f=2+1$ domain-wall fermion phenomenology programme. These quantities were obtained with a good precision and, in particular, the expected effects of $SU(3)$-flavour symmetry breaking were observed. Operators were renormalised non-perturbatively and extrapolations to the physical point were made, guided by leading order chiral perturbation theory. The main results presented are for two volumes, $16^3\\times 32$ and $24^3\\times 64$, with a common lattice spacing. Preliminary results for a lattice with a finer lattice spacing, $32^3\\times64$, are discussed and a first look is taken at the use of twisted boundary conditions to extract distribution amplitudes.
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
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.)
An interacting multielectron Anderson model
Zenk, H
2003-01-01
This article is a first tiny step towards a rigorous description of an interacting multielectron system in a random potential of Anderson type. Deterministic spectrum and a Wegner estimate for this model are proven.
Lithuania 1940 / Herbert Foster Anderson
Foster Anderson, Herbert
2004-01-01
Stseenid Leedu ennesõjaaegsest pealinnast Kaunasest briti ärimehe H. Foster Andersoni silme läbi 1940. aastal. Lühikokkuvõte raamatust: Foster Anderson, Herbert. Borderline Russia. London : Cresset press, 1942
International Nuclear Information System (INIS)
Jones, R.
2000-01-01
The Price-Anderson Act establishes nuclear liability law in the United States. First passed in 1957, it has influenced other nuclear liability legislation around the world. The insurer response the nuclear accident at Three Mile Island in 1979 demonstrates the application of the Act in a real life situation. The Price-Anderson Act is scheduled to be renewed in 2002, and the future use of commercial nuclear power in tge United States will be influenced by this renewal. (author)
Theoretical overview: The New mesons
Energy Technology Data Exchange (ETDEWEB)
Quigg, Chris; /Fermilab
2004-11-01
After commenting on the state of contemporary hadronic physics and spectroscopy, I highlight four areas where the action is: searching for the relevant degrees of freedom, mesons with beauty and charm, chiral symmetry and the D{sub sJ} levels, and X(3872) and the lost tribes of charmonium.
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
Indian Academy of Sciences (India)
... 13 December 1923. Address: Department of Physics, Joseph Henry Laboratories, Princeton University, Jadwin Hall, Post Box 708, Princeton, NJ 08544-0708, U.S.A.. Contact: Office: (+1-609) 258 5850. Residence: (+1-609) 454 5075. Fax: (+1-609) 258 1006. Email: pwa@princeton.edu. YouTube; Twitter; Facebook; Blog ...
International Nuclear Information System (INIS)
Madsen, V.A.; Landau, R.H.
1986-01-01
Final technical report on a contract supporting theoretical studies in nuclear physics at Oregon State University is presented. The research was led by Professors Landau and Madsen and carried out in collaboration with graduate students in Corvallis and scientists at LLNL-Livermore, KFA-Julich, Purdue University-West Lafayette, University of Oregon-Eugene, Florida State University-Talahasie, and TRIUMF-Vancouver. The studies included meson exchange current effects, quark effects,and relativistic/Dirac effects deduced from spin observables in p- 3 He scattering, coupled bound and continuum eigenstates in momentum space for kaons and antiprotons, and charge symmetry violation in π scattering from trinucleons. Additional studies included microscopic optical potential calculations, multiple step processes, and differences in neutron and proton multipole matrix elements in low lying collective states and in giant resonances. 45 refs
Anderson's Relevant Deontic and Eubouliatic Systems
Lokhorst, G.J.C.
2008-01-01
We present axiomatizations of the deontic fragment of Anderson's relevant deontic logic (the logic of obligation and related concepts) and the eubouliatic fragment of Anderson's eubouliatic logic (the logic of prudence, safety, risk, and related concepts).
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.)
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
PWA90 Workshop : Marking the Scientific Accomplishments of Philip W. Anderson
Coleman, PIers; Kotliar, Gabi; Ong, Phuan; Stein, Daniel L; Yu, Clare; PWA90 : a lifetime of emergence
2016-01-01
In a remarkable career spanning more than six decades, Philip W Anderson has made many fundamental contributions to physics. As codified in his oft-quoted phrase "More is Different", Anderson has been the most forceful and persuasive proponent of the radical, but now ubiquitous, viewpoint of emergent phenomena: truly fundamental concepts that can and do emerge from studies of Nature at each layer of complexity or energy scale. Anderson's ideas have also extended deeply into other areas of physics, including the Anderson–Higgs mechanism and the dynamics of pulsars. PWA90: A Lifetime of Emergence is a volume of original scientific essays and personal reminiscences of Philip W Anderson by experts in the field, that were presented as part of "PWA90: Emergent Frontiers of Condensed Matter" meeting held at Princeton in December 2013 to highlight Anderson's contributions to physics.
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}.
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.
Chen, Kan; Pang, Cheng-Qun; Liu, Xiang; Matsuki, Takayuki
2015-04-01
Inspired by the abundant experimental observation of axial-vector states, we study whether the observed axial-vector states can be categorized into the conventional axial-vector meson family. In this paper we carry out an analysis based on the mass spectra and two-body Okubo-Zweig-Iizuka-allowed decays. Besides testing the possible axial-vector meson assignments, we also predict abundant information for their decays and the properties of some missing axial-vector mesons, which are valuable for further experimental exploration of the observed and predicted axial-vector mesons.
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
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
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.
Studies of Light Pseudoscalar Mesons at BESIII
Directory of Open Access Journals (Sweden)
Redmer C. F
2014-05-01
Full Text Available Studies of light pseudoscalar mesons are an important aspect of the physics program pursued at BESIII. In this presentation recent results from η and η′ decays and the current status of the γγ physics program will be 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.
Interplay of Anderson localization and strong interaction in disordered systems
Energy Technology Data Exchange (ETDEWEB)
Henseler, Peter
2010-01-15
We study the interplay of disorder localization and strong local interactions within the Anderson-Hubbard model. Taking into account local Mott-Hubbard physics and static screening of the disorder potential, the system is mapped onto an effective single-particle Anderson model, which is studied within the self-consistent theory of electron localization. For fermions, we find rich nonmonotonic behavior of the localization length {xi}, particularly in two-dimensional systems, including an interaction-induced exponential enhancement of {xi} for small and intermediate disorders and a strong reduction of {xi} due to hopping suppression by strong interactions. In three dimensions, we identify for half filling a Mott-Hubbard-assisted Anderson localized phase existing between the metallic and the Mott-Hubbard-gapped phases. For small U there is re-entrant behavior from the Anderson localized phase to the metallic phase. For bosons, the unrestricted particle occupation number per lattice site yields a monotonic enhancement of {xi} as a function of decreasing interaction, which we assume to persist until the superfluid Bose-Einstein condensate phase is entered. Besides, we study cold atomic gases expanding, by a diffusion process, in a weak random potential. We show that the density-density correlation function of the expanding gas is strongly affected by disorder and we estimate the typical size of a speckle spot, i.e., a region of enhanced or depleted density. Both a Fermi gas and a Bose-Einstein condensate (in a mean-field approach) are considered. (orig.)
Interplay of Anderson localization and strong interaction in disordered systems
International Nuclear Information System (INIS)
Henseler, Peter
2010-01-01
We study the interplay of disorder localization and strong local interactions within the Anderson-Hubbard model. Taking into account local Mott-Hubbard physics and static screening of the disorder potential, the system is mapped onto an effective single-particle Anderson model, which is studied within the self-consistent theory of electron localization. For fermions, we find rich nonmonotonic behavior of the localization length ξ, particularly in two-dimensional systems, including an interaction-induced exponential enhancement of ξ for small and intermediate disorders and a strong reduction of ξ due to hopping suppression by strong interactions. In three dimensions, we identify for half filling a Mott-Hubbard-assisted Anderson localized phase existing between the metallic and the Mott-Hubbard-gapped phases. For small U there is re-entrant behavior from the Anderson localized phase to the metallic phase. For bosons, the unrestricted particle occupation number per lattice site yields a monotonic enhancement of ξ as a function of decreasing interaction, which we assume to persist until the superfluid Bose-Einstein condensate phase is entered. Besides, we study cold atomic gases expanding, by a diffusion process, in a weak random potential. We show that the density-density correlation function of the expanding gas is strongly affected by disorder and we estimate the typical size of a speckle spot, i.e., a region of enhanced or depleted density. Both a Fermi gas and a Bose-Einstein condensate (in a mean-field approach) are considered. (orig.)
Benedict Andersons forestillede fællesskaber
DEFF Research Database (Denmark)
Ivarsson, Søren
2007-01-01
Artiklen diskuterer Benedict Andersons analyse af nationalismens opståen i en kolonial kontekst og den kritik som Partha Chatterjee har rejst mod denne. Udgivelsesdato: Januar 2008......Artiklen diskuterer Benedict Andersons analyse af nationalismens opståen i en kolonial kontekst og den kritik som Partha Chatterjee har rejst mod denne. Udgivelsesdato: Januar 2008...
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
Discrete symmetries with neutral mesons
Bernabéu, José
2018-01-01
Symmetries, and Symmetry Breakings, in the Laws of Physics play a crucial role in Fundamental Science. Parity and Charge Conjugation Violations prompted the consideration of Chiral Fields in the construction of the Standard Model, whereas CP-Violation needed at least three families of Quarks leading to Flavour Physics. In this Lecture I discuss the Conceptual Basis and the present experimental results for a Direct Evidence of Separate Reversal-in-Time T, CP and CPT Genuine Asymmetries in Decaying Particles like Neutral Meson Transitions, using Quantum Entanglement and the Decay as a Filtering Measurement. The eight transitions associated to the Flavour-CP eigenstate decay products of entangled neutral mesons have demonstrated with impressive significance a separate evidence of TRV and CPV in Bd-physics, whereas a CPTV asymmetry shows a 2σ effect interpreted as an upper limit. Novel CPTV observables are discussed for K physics at KLOE-2, including the difference between the semileptonic asymmetries from KL and KS, the ratios of double decay rate Intensities to Flavour-CP eigenstate decay products and the ω-effect. Their observation would lead to a change of paradigm beyond Quantum Field Theory, however there is nothing in Quantum Mechanics forbidding CPTV.
Dowdall, R J; Davies, C T H; Horgan, R R; Monahan, C J; Shigemitsu, J
2013-05-31
We present the first lattice QCD calculation of the decay constants f(B) and f(B(s)) with physical light quark masses. We use configurations generated by the MILC Collaboration including the effect of u, d, s, and c highly improved staggered quarks in the sea at three lattice spacings and with three u/d quark mass values going down to the physical value. We use improved nonrelativistic QCD (NRQCD) for the valence b quarks. Our results are f(B)=0.186(4) GeV, f(B(s))=0.224(4) GeV, f(B(s))/f(B)=1.205(7), and M(B(s))-M(B)=85(2) MeV, superseding earlier results with NRQCD b quarks. We discuss the implications of our results for the standard model rates for B((s))→μ(+)μ(-) and B→τν.
Extracting excited mesons from the finite volume
Energy Technology Data Exchange (ETDEWEB)
Doring, Michael [George Washington Univ., Washington, DC (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2014-12-01
As quark masses come closer to their physical values in lattice simulations, finite volume effects dominate the level spectrum. Methods to extract excited mesons from the finite volume are discussed, like moving frames in the presence of coupled channels. Effective field theory can be used to stabilize the determination of the resonance spectrum.
Eugenio, Paul
2016-03-01
tudies of meson spectra via strong decays provide insight regarding QCD at the confinement scale. These studies have led to phenomenological models 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 hybrids, exotics, multi-quarks, and glueballs. Within the past two decades a number of experiments have put forth tantalizing evidence for the existence of light quark exotic hybrid mesons in the mass range below 2 GeV . Recent Lattice QCD calculations of the light-quark meson spectrum indicate a constituent gluon-like excitation contributing an additional JPC =1+- and mass 1 - 1 . 5 GeV resulting in the lightest hybrid nonets with masses near 2 . 0 GeV . High statistical yields from recent experiments along with new advances in analysis techniques have shed a new light towards the understanding the latest experimental exotic candidates. Recent results from hadro-production and photo-production will be presented followed by an overview of ongoing and future efforts to search for light exotic mesons.
On the Anderson localization conjecture in Dusty Plasma
Liaw, Constanze; Busse, Kyle; Matthews, Lorin; Hyde, Truell
2015-11-01
In 1958, Anderson suggested that sufficiently large impurities in a semi-conductor could lead to spatial localization of electrons. This idea unfolded into the field of Anderson Localization, one of the most fascinating phenomena in solid-state physics as it plays a major role in the conductive properties of imperfectly ordered materials. The Anderson Localization Conjecture claims that random disorder of any strength causes localization of electrons in the medium. The problem has proven to be highly non-trivial. Over the years the community has argued whether spatial localization occurs in 2D for small impurities. From a mathematical standpoint, the conjecture is still considered an open question. In 2013, Liaw challenged the commonly held assumption that localization holds in 2D by introducing a new mathematically more rigorous method to test for extended states, and applying it to the discrete random Schrödinger operator. One of the advantages of the underlying method is its versatility. It can be applied to any ordered system such as colloids, crystals, and atomic lattices. In a cross-disciplinary effort we merge this method with a numerical code used to simulate 2D physics systems, in preparation for experimentally testing the theory against complex plasma crystals.
Mott transitions in the periodic Anderson model
International Nuclear Information System (INIS)
Logan, David E; Galpin, Martin R; Mannouch, Jonathan
2016-01-01
The periodic Anderson model (PAM) is studied within the framework of dynamical mean-field theory, with particular emphasis on the interaction-driven Mott transition it contains, and on resultant Mott insulators of both Mott–Hubbard and charge-transfer type. The form of the PAM phase diagram is first deduced on general grounds using two exact results, over the full range of model parameters and including metallic, Mott, Kondo and band insulator phases. The effective low-energy model which describes the PAM in the vicinity of a Mott transition is then shown to be a one-band Hubbard model, with effective hoppings that are not in general solely nearest neighbour, but decay exponentially with distance. This mapping is shown to have a range of implications for the physics of the problem, from phase boundaries to single-particle dynamics; all of which are confirmed and supplemented by NRG calculations. Finally we consider the locally degenerate, non-Fermi liquid Mott insulator, to describe which requires a two-self-energy description. This is shown to yield a number of exact results for the associated local moment, charge, and interaction-renormalised levels, together with a generalisation of Luttinger’s theorem to the Mott insulator. (paper)
Schemata, Cognitive Structure, and Advance Organizers: A Reply to Anderson, Spiro, and Anderson.
Ausubel, David P.
1980-01-01
Anderson, Spiro, and Anderson (EJ 189 658) assert that the author's assimilation theory of meaningful learning and retention is "hopelessly vague." Documented examination of these assertions indicates that they are unspecified, unsubstantiated, undocumented, and based on indisputable misrepresentation of published material and on logical…
Indian Academy of Sciences (India)
−0.16 ps [1]. 4. Conclusion. Based on a simple nonrelativistic potential scheme within variational approach we have been able to predict the S- and P-wave masses and lifetime of B+ c meson successfully. Mass spectrum and pseudoscalar decay constants fBc are computed for the potential index (ν) from 0.5 to 2.
Indian Academy of Sciences (India)
antiquark potential of the form − c r + A r with varying from 0.5 to 2.0. The and -wave masses, pseudoscalar decay constant, weak decay partial widths in spectator model and the lifetime of c meson are computed. The properties calculated ...
International Nuclear Information System (INIS)
Bonnet, Frederic D.R.; Edwards, Robert G.; Felming, George T.; Randal Lewis; David Richards
2003-01-01
We have started a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present preliminary results computed with domain wall valence fermions on MILC asqtad lattices, as well as Wilson fermions on quenched lattices. These methods can easily be extended to rho-to-gamma-pi transition form factors
Indian Academy of Sciences (India)
One consequence of the chiral restoration is the mixing of parity partners. We look for a possible signature of the mixing of vector and axial vector mesons in heavy-ion collisions. We suggest an experimental method for its observation. The dynamical evolution of the heavy-ion collision is described by a transport equation of ...
International Nuclear Information System (INIS)
Lanius, K.
1977-01-01
Some of the essential results are given of the hadron spectroscopy which have been obtained in the last two years. The progress in meson spectroscopy originates in high statistics and in the extensive use of partial wave analysis. The resonances established fill the major meson multiplets. The rotational excitation (α)=0 multiplet is complete. With regard to the gaps in the 1 ++ and 1 +- nonets of the α=1 multiplet there are some good condidates, like Q 2 (1400) and D(1285). Concerning the α=2 and 3 multiplets, there are only very few established states. The reactions that should be studied in searching for the missing states are exclusive channels with multiparticle final state. Both the new evidence about meson resonances and the non-evidence for exotic states, which cannot be represented as a bound q anti q pair, show that the general pattern of meson states is in agreement with the naive nonrelativistic quark model. The summary of SU(6)xO(3) multiplets, as far as it belongs to the distribution of the observed resonances among the different multiplets, can be changed in future. Only the [56.0 + ] can be considered as well established concerning the distribution of the states. As far as it belongs to the [56.1 - ], [70.2 + ] and the second [56.2 + ], additional confirmations are necessary
A proposal to extend the intensity frontier of nuclear and particle physics to 45 GeV (LAMPF 2)
International Nuclear Information System (INIS)
1984-12-01
It is proposed to construct and operate a high-intensity, medium energy synchrotron addition to the Clinton P. Anderson Meson Physics Facility. The addition is to consist of a 6-GeV, 170-μA booster and a 45-GeV, 34-μA, 3-Hz main synchrotron with 50% duty factor. The physics of strong and electroweak interactions to be studied at the facility is discussed, as well as accelerator design, scope of experimental area facilities, and cost estimates and schedule
meson properties and its leptonic radiative decays
Indian Academy of Sciences (India)
Abstract. The properties of the meson B are outlined. The leptonic radiative decays for B meson are presented. An outlook on the studies of the meson is given. Keywords. B-meson; properties; radiative decays. PACS Nos 14.40.Lb; 14.40.Nd; 13.20.-v; 13.20.Jf. 1. Introduction. According to the terminology of PDG, the meson.
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
Random nanolasing in the Anderson localized regime
DEFF Research Database (Denmark)
Liu, Jin; Garcia, P. D.; Ek, Sara
2014-01-01
multiple scattering. The applicability of random lasers has been limited due to multidirectional emission, lack of tunability, and strong mode competition with chaotic fluctuations due to a weak mode confinement. The regime of Anderson localization of light has been proposed for obtaining stable multimode...... random lasing, and initial work concerned macroscopic one-dimensional layered media. Here, we demonstrate on-chip random nanolasers where the cavity feedback is provided by the intrinsic disorder. The strong confinement achieved by Anderson localization reduces the spatial overlap between lasing modes...
B meson decays into charmless pseudoscalar scalar mesons
International Nuclear Information System (INIS)
Delepine, D.; Lucio M, J. L.; Ramirez, Carlos A.; Mendoza S, J. A.
2007-01-01
The nonleptonic weak decays of meson B into a scalar and pseudoscalar meson are studied. The scalar mesons under consideration are σ (or f0(600)), f0(980), a0(980) and K 0 * (1430). We calculate the Branching ratios in the Naive Factorization approximation. Scalars are assumed to be qq-bar bounded sates, but an estimation can be obtained in the case they are four bounded states
{eta} meson photoproduction on deuterium; Photoproduction du meson {eta} sur le deuterium
Energy Technology Data Exchange (ETDEWEB)
Hoffmann-Rothe, P.
1996-05-30
Measurements of the total and differential cross sections for {eta}-meson photoproduction on a D{sub 2} liquid target from threshold to 1.2 GeV, have been taken using the tagged Bremsstrahlung photon beam produced by the electrons extracted from the ELSA storage ring at Bonn. The reaction was identified by detecting the eta decay products in the neutral meson spectrometer SPES0-2{pi}, while the recoil baryons (proton, neutron or deuteron) were detected by a variety of large angle scintillator detectors. We succeeded to identify completely the final states corresponding to the production of an {eta} meson on a Quasi-Free (QF) proton, a QF neutron and the coherent deuteron. The differential cross sections corresponding to the production of a coherent deuteron n the final state have been measured, from threshold to 800 MeV; they are 6 times smaller the only previous measurement reported by Anderson and Prepost in 1969. This is consistent with an Isoscalar part of the Amplitude much smaller than the Isovector one. The differential cross sections are in good agreement with the theoretical prediction on the impulse approximation mechanism; indicating in particular, fairly small contributions from rescattering terms. A direct measurement of the neutron to proton cross section ratios has been obtained by integrating the counting rates on the corresponding QF peaks and is 0.70 {+-} 0.03, from 700 MeV to 900 MeV, with a small angular dependence. These two results by comparison to the measured free proton data should allow to reconstruct the free neutron cross sections in a rather model-independent way. (authors). 56 refs., 90 figs., 13 tabs.
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-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.)
Signatures of Anderson localization excited by an optical frequency comb
Gentilini, S.
2010-01-25
We investigate Anderson localization of light as occurring in ultrashort excitations. A theory based on time dependent coupled-mode equations predicts universal features in the spectrum of the transmitted pulse. In particular, the process of strong localization of light is shown to correspond to the formation of peaks in both the amplitude and in the group delay of the transmitted pulse. Parallel ab initio simulations made with finite-difference time-domain codes and molecular dynamics confirm theoretical predictions, while showing that there exists an optimal degree of disorder for the strong localization. © 2010 The American Physical Society.
Photoproduction of pseudoscalar mesons
International Nuclear Information System (INIS)
Arndt, R.A.; Briscoe, W.J.; O'Rielly, G.V.; Strakovsky, I.I.; Workman, R.L.
2003-01-01
Experiments that study the photoproduction of pseudoscalar mesons; pions, etas and kaons, have the potential to increase our knowledge of baryon and hyperon resonance properties. Recent experiments at JLab, Mainz, GRAAL, and Bonn are beginning to produce results in the form of polarization and asymmetry measurements and determinations of the differential and integrated cross sections. These new data are essential to the performance of Partial-Wave Analyses that are less model dependent and coupled-channels calculations that incorporate unitarity dynamically, combining hadronic reaction channels together with electromagnetic processes. This approach is necessary to extract resonance properties and may lead to the identification of missing, but predicted, resonances. Some recent experimental and phenomenological results for single and double pseudoscalar meson photoproduction are discussed
Energy Technology Data Exchange (ETDEWEB)
Hooft, G. t' [Institute for Theoretical Physics, Utrecht University, and Spinoza Institute, Postbus 8000, 3508 TA Utrecht (Netherlands); Isidori, G. [Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); INFN, Laboratori Nazionali di Frascati, Via E.Fermi 40, 00044 Frascati (Italy); Maiani, L. [Dipartimento di Fisica, Universita di Roma ' La Sapienza' , P.le A. Moro 2, 00185 Roma (Italy); INFN, Sezione di Roma ' La Sapienza' , P.le A. Moro 2, 00185 Roma (Italy); Polosa, A.D. [INFN, Sezione di Roma ' La Sapienza' , P.le A. Moro 2, 00185 Roma (Italy)], E-mail: antonio.polosa@cern.ch; Riquer, V. [INFN, Sezione di Roma ' La Sapienza' , P.le A. Moro 2, 00185 Roma (Italy)
2008-05-08
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.
Effect of coulomb interaction on Anderson localization
International Nuclear Information System (INIS)
Waintal, X.
1999-01-01
We study the quantum mechanics of interacting particles in a disordered system, and in particular, what happens to Anderson localisation when interaction is taken into account. In the first part, one looks at the excited states of two particles in one dimension. For this model, it has been shown (Shepelyansky 1994) that a local repulsive interaction can partially destroy Anderson localisation. Here, we show that this model has similarities with the three-dimensional Anderson model at the metal-insulator transition. In particular, the maximum of rigidity obtained in the spectral statistics correspond to some intermediary statistics that cannot be described by random matrix theory neither by a Poisson statistics. The wave functions show a multifractal behaviour and the spreading of the center of mass of a wave packet is logarithmic in time. The second part deals with the ground state of a finite density of spinless fermions in two dimensions. After the scaling theory of localisation, it was commonly accepted that there was no metal in two dimensions. This idea has been challenged by the observation of a metal-insulator transition in low density electron gas (Kravchenko et al. 1994). We propose a scenario in which a metallic phase occurs between the Anderson insulator and the pinned Wigner crystal. This intermediate phase is characterized by an alignment of the local currents flowing in the system. (author)
Effects of the magnetic dipole moment of charged vector mesons in their radiative decay distribution
International Nuclear Information System (INIS)
Castro, G.L.; Sanchez, G.T.
1997-01-01
We consider the effects of anomalous magnetic dipole moments of vector mesons in the decay distribution of photons emitted in two-pseudoscalar decays of charged vector mesons. By choosing a kinematical configuration appropriate to isolate these effects from model-dependent and dominant bremsstrahlung contributions, we show that this method can provide a valid alternative for a measurement of the unknown magnetic dipole moments of charged vector mesons. copyright 1997 The American Physical Society
MesonNet Workshop on Meson Transition Form Factors
Eidelman, S; Hanhart, C; Kubis, B; Kupsc, A; Leupold, S; Moskal, P; Schadmand, S
2012-01-01
The mini-proceedings of the Workshop on Meson Transition Form Factors held in Cracow from May 29th to 30th, 2012 introduce the meson transition form factor project with special emphasis on the interrelations between the various form factors (on-shell, single off-shell, double off-shell). Short summaries of the talks presented at the workshop follow.
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
The hybrid mesons quest: the MesonEx experiment at Jefferson Laboratory
Energy Technology Data Exchange (ETDEWEB)
Rizzo, Alessandro [Univ. of Rome Tor Vergata (Italy)
2016-03-01
The meson spectroscopy plays nowadays a central role in the investigation of hadron structure thanks to the possible existence of exotic hybrid mesons, quark-antiquark-gluon bound states. Their explicit gluonic degrees of freedom which should clearly emerge from a Partial Wave Analysis (PWA) of the corresponding Dalitz plot of the exotic particle decay, may result in final JPC configurations not allowed in the constituent quark model. Besides this clear signature, hybrid mesons are also expected to have a large particle multiplicity decays, requiring for their search an experimental apparatus with high performances in terms of rate capability, resolution and almost a full acceptance to apply PWA methods. New-generation experiments are planned at Thomas Jefferson National Laboratory (VA, USA) for which an unprecedented statistics of large multiplicity decay events with fully reconstructed kinematics will be available. In particular for the MesonEx (CLAS12) experiment in Hall B, a wide scientific program that will start in 2016 has been deployed to study the meson spectrum at energies up to 11 GeV. A key role in such program is played by the Forward Tagger apparatus of the experiment, which will allow to extend the study of meson electro-production to very low Q2 values, in a quasi-real photo production kinematical region, where the production of hybrid mesons is expected to be favorite. Currently a new analysis framework for the search of the hybrid mesons is being set up by the HASPECT network, an international structure which gather people involved into theoretical and experimental hadronic physics all over the world. The goals of the network is to develop new analysis models and statistical techniques to unfold the signal and background distributions in high-statistics datasets. In this work are briefly presented the first preliminary results from the application of a statistical technique, namely the sPlot, to the data already acquired by the CLAS experiment for
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.
Glueballs and vector mesons at NICA
Parganlija, Denis
2016-08-01
Two interconnected fields of interest are suggested for NICA. Firstly, existence of glueballs is predicted by the theory of strong interaction but --even after decades of research-- glueball identification in the physical spectrum is still unclear. NICA can help to ascertain experimental glueball candidates via J/Ψ decays whose yield is expected to be large. Importance of glueballs is not limited to vacuum: since they couple to other meson states, glueballs can also be expected to influence signatures of chiral-symmetry restoration in the high-energy phase of strong dynamics. Mass shifting or in-medium broadening of vector and axial-vector mesons may occur there but the extent of such phenomena is still uncertain. Additionally, glueball properties could also be modified in medium. Exploration of these issues is the second suggested field of interest that can be pursued at NICA.
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
Energy Technology Data Exchange (ETDEWEB)
Acosta, D.; The CDF Collaboration
2005-05-25
We report the first evidence of a fully reconstructed decay mode of the B{sub c}{sup {+-}} meson in the channel B{sub c}{sup {+-}} {yields} J/{psi}{sup {+-}}, with J/{psi} {yields} {mu}{sup +}{mu}{sup -}. The analysis is based on an integrated luminosity of 360 pb{sup -1} in p{bar p} collisions collected by the Collider Detector at Fermilab. We observe 18.9 {+-} 5.7 signal events on a background of 10.0 {+-} 1.4 events and the fit to the J/{psi}{pi}{sup {+-}} mass spectrum yields a B{sub c}{sup {+-}} mass of 6287.0 {+-} 4.8(stat) {+-} 1.1(syst) MeV/c{sup 2}.
Anderson introduces a new biomass baler
Energy Technology Data Exchange (ETDEWEB)
D' amour, L.; Lavoie, F. [Anderson Group Co., Chesterville, PQ (Canada)
2010-07-01
Canadian-based Anderson Group Company has developed an innovative round baler for harvesting a large variety of woody biomass. The baler was initially developed in 2005 in collaboration with the University Laval and Agriculture and Agri-Food Canada. The third generation BIOBALER{sup TM} is currently built, engineered and commercialized by Anderson. It can produce up to 40 bales/hr in short rotations woody crops such as willow and hybrid poplar. The unit can harvest brushes up to 125 mm in diameter. A standard tractor can pull the BIOBALER in fallow or abandoned land, under power transmission lines, and between planted trees. The patented BIOBALER includes a mulcher head attachment, a choice of long or short swivel tongue, a fixed chamber and an undercarriage frame.
Haas, Florian
2009-01-01
QCD predicts four quark states or gluonic excitations like hybrids or glueballs to contribute to the meson spectrum in addition to $q\\overline{q}$ pair configurations. The most promising way to identify such states is the search for $J^{PC}$ quantum number combinations which are forbidden in the constituent quark model. The fixed target COMPASS experiment at CERN offers the opportunity to search for such states in the light quark sector with an unprecedented statistics. Diffractive reactions of 190 GeV/c pions on a lead target were studied by COMPASS during a pilot run in 2004. A Partial Wave Analysis (PWA) of the $\\pi^{−}\\pi^{−}\\pi^{+}$ final state with 42 waves including acceptance corrections through a phase-space Monte Carlo simulation of the spectrometer was performed. The exotic $\\pi_{1}$(1600) meson with quantum numbers $J^{PC}= 1^{−+}$ has been clearly established in the rho-pi decay channel with a mass of 1660 $\\pm$ 10(stat) MeV/c$^{2}$ and a width of 269 $\\pm$ 21(stat) MeV/c$^{2}$. The final s...
Grube, Boris
2016-11-29
The goal of the COMPASS experiment at CERN is to study the structure and dynamics of hadrons. The two-stage spectrometer used by the experiment has large acceptance and covers a wide kinematic range for charged as well as neutral particles and can therefore measure a wide range of reactions. The spectroscopy of light mesons is performed with negative (mostly $\\pi^-$) and positive ($p$, $\\pi^+$) hadron beams with a momentum of 190 GeV/$c$. The light-meson spectrum is measured in different final states produced in diffractive dissociation reactions with squared four-momentum transfer $t$ to the target between 0.1 and 1.0 $(\\text{GeV}/c)^2$. The flagship channel is the $\\pi^-\\pi^-\\pi^+$ final state, for which COMPASS has recorded the currently world's largest data sample. These data not only allow to measure the properties of known resonances with high precision, but also to observe new states. Among these is a new axial-vector signal, the $a_1(1420)$, with unusual properties. Novel analysis techniques have been...
Brownian motion and parabolic Anderson model in a renormalized Poisson potential
Chen, Xia; Kulik, Alexey M.
2012-01-01
A method known as renormalization is proposed for constructing some more physically realistic random potentials in a Poisson cloud. The Brownian motion in the renormalized random potential and related parabolic Anderson models are modeled. With the renormalization, for example, the models consistent to Newton’s law of universal attraction can be rigorously constructed.
DEFF Research Database (Denmark)
Opper, Manfred; Winther, Ole
2001-01-01
We develop an advanced mean held method for approximating averages in probabilistic data models that is based on the Thouless-Anderson-Palmer (TAP) approach of disorder physics. In contrast to conventional TAP. where the knowledge of the distribution of couplings between the random variables...
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.
Anderson localization and Mott insulator phase in the time domain
Sacha, Krzysztof
2015-01-01
Particles in space periodic potentials constitute standard models for investigation of crystalline phenomena in solid state physics. Time periodicity of periodically driven systems is a close analogue of space periodicity of solid state crystals. There is an intriguing question if solid state phenomena can be observed in the time domain. Here we show that wave-packets localized on resonant classical trajectories of periodically driven systems are ideal elements to realize Anderson localization or Mott insulator phase in the time domain. Uniform superpositions of the wave-packets form stationary states of a periodically driven particle. However, an additional perturbation that fluctuates in time results in disorder in time and Anderson localization effects emerge. Switching to many-particle systems we observe that depending on how strong particle interactions are, stationary states can be Bose-Einstein condensates or single Fock states where definite numbers of particles occupy the periodically evolving wave-packets. Our study shows that non-trivial crystal-like phenomena can be observed in the time domain. PMID:26074169
Czech Academy of Sciences Publication Activity Database
Pokorný, Vladislav; Žonda, M.; Kauch, Anna; Janiš, Václav
2017-01-01
Roč. 131, č. 4 (2017), s. 1042-1044 ISSN 0587-4246 R&D Projects: GA ČR GA15-14259S Institutional support: RVO:68378271 Keywords : Anderson model * parquet equations * numerical renormalization group Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 0.469, year: 2016
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)
International Nuclear Information System (INIS)
Chakrabarty, S.
1989-08-01
In this article we give a review of certain aspects of the present understanding of spectroscopy of heavy mesons and constituent quark masses in the light of non-relativistic potential model approach motivated by quantum chromodynamics. We find that the one gluon exchange at short distance and colour-confining interaction at large distance which is pure scalar (or scalar-vector admixture with dominant scalar interaction) under the Lorentz transformation, can explain only partially the present data on 1P states of cc-bar and bb-bar states. The S-wave data, that are available at present, however can be understood with both scalar confinement or scalar-vector admixture with scalar-dominant interaction. (author). 44 refs, 13 tabs
Price-Anderson Act and nuclear insurance
International Nuclear Information System (INIS)
Long, J.D.; Long, D.P.
1979-01-01
The nuclear incident at Three Mile Island has served to intensify debate about elimination of the federal limit on liability of utilities (and others) for operation of private nuclear reactions and about elimination of possible federal indemnification of utilities (or others) for claims paid in nuclear incidents. Not all those who debate these issues appear to be fully informed about the present nuclear liability and insurance system. This paper provides a brief description of the Price-Anderson Act, as amended, and of the operation of the nuclear insurance pools. It also includes a comment on the recent federal district court award against the Kerr-McGee Corporation
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
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
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.
International Nuclear Information System (INIS)
Truhlik, E.; Mach, R.
1992-01-01
62 papers and one summary talk were presented at the conference, on subject matters in between nuclear physics (mainly light nuclei) and elementary particle physics, as indicated by the session headings (1) Electroweak nuclear interaction (2) Nuclear physics with pions and antiprotons (3) Nuclear physics with strange particles (4) Relativistic nuclear physics (5) Quark degrees of freedom. (Quittner)
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
Beam tomography or ART in accelerator physics
International Nuclear Information System (INIS)
Fraser, J.S.
1978-11-01
Projections of charged particle beam current density have been used for many years as a measure of beam position and size. The conventional practice of obtaining only two projections, usually in the horizontal and vertical planes, puts a severe limit on the detail that can be recovered from the projections. A third projection provides sufficient improvement to justify the addition of a wire to the conventional wire scanner in certain cases. A group of programs using algebraic reconstruction techniques was written to reconstruct beam current density from beam projections obtained at three or more specific or arbitrary angles around the beam. A generalized program, which makes use of arbitrary 2 x 2 transfer matrices between projections, can be used to reconstruct transverse or longitudinal emittance from appropriate projections. Reconstruction examples of beam current density and transverse and longitudinal emittance using experimental data from the Clinton P. Anderson Meson Physics Facility (LAMPF) accelerator beam are given
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.)
Leptonic Decays of Charged Pseudoscalar Mesons - 2015
Energy Technology Data Exchange (ETDEWEB)
Rosner, Jonathan L. [Chicago U., EFI; Stone, Sheldon [Syracuse U.; Van de Water, Ruth S. [Fermilab
2015-09-07
We review the physics of purely leptonic decays of $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of the constituent quarks and a strong interaction parameter related to the overlap of the quark and antiquark wave-functions in the meson, called the decay constant $f_P$. The leptonic decay constants for $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ mesons can be obtained with controlled theoretical uncertainties and high precision from {\\it ab initio} lattice-QCD simulations. The combination of experimental leptonic decay-rate measurements and theoretical decay-constant calculations enables the determination of several elements of the CKM matrix within the standard model. These determinations are competitive with those obtained from semileptonic decays, and also complementary because they are sensitive to different quark flavor-changing currents. They can also be used to test the unitarity of the first and second rows of the CKM matrix. Conversely, taking the CKM elements predicted by unitarity, one can infer "experimental" values for $f_P$ that can be compared with theory. These provide tests of lattice-QCD methods, provided new-physics contributions to leptonic decays are negligible at the current level of precision. This review is the basis of the article in the Particle Data Group's 2016 edition, updating the versions in Refs. [1-3].
Bianchi Type-I cosmological mesonic stiff fluid models in Lyra's ...
Indian Academy of Sciences (India)
Bianchi Type-I cosmological models in Lyra's geometry are obtained when the source of gravitational field is a perfect fluid coupled with massless mesonic scalar field. Some physical and kinematical properties of the models are also discussed.
Mesonic and Non-Mesonic Weak Decay of Hypernuclei with FINUDA
International Nuclear Information System (INIS)
Agnello, M.; Andronenkov, A.; Beer, G.; Benussi, L.; Bertani, M.; Bhang, H.C.; Bonomi, G.; Botta, E.; Bregant, M.; Bressani, T.; Bufalino, S.; Busso, L.; Calvo, D.; Camerini, P.; Dalena, B.; De Mori, F.; D'Erasmo, G.
2009-01-01
The FINUDA experiment performed a systematic study of both mesonic and non-mesonic weak decay of p-shell Λ-hypernuclei. Recent results on the mesonic decay rates and the non-mesonic decay ratios are illustrated and briefly discussed.
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
Lepton decay constants of light mesons
International Nuclear Information System (INIS)
Simonov, Yu. A.
2016-01-01
A theory of lepton decay constants based on the path-integral formalism is given for chiral and vector mesons. Decay constants of the pseudoscalar and vector mesons are calculated and compared to other existing results.
Meson production in + reactions
Indian Academy of Sciences (India)
... Krakow, Poland; Institut für Kernphysik, Universität Münster, Münster, Germany; Institute of Nuclear Physics and Nuclear Energy, Sofia, Bulgaria; Institute of Physics, Jagellonian University, Krakow, Poland; Physics Faculty, University of Sofia, Sofia, Bulgaria; Physics Department, George Mason University, Fairfax, Virginia, ...
Anderson Exploration Ltd. 1998 annual report
International Nuclear Information System (INIS)
1999-01-01
In 1998, Anderson Exploration's undeveloped land inventory in the western provinces decreased 7% to 3,183,000 net acres largely due to lease expiries and drilling activity. The undeveloped land base is located 63% in Alberta, 19% in British Columbia, 17% in Saskatchewan, and 1% in Manitoba. During 1998, Anderson Exploration participated in drilling 446 wells for oil and gas vs. 669 for 1997. The average working interest in the wells was 63% vs. 64% in 1997. In 1998, the company spent $109 million on the construction of field gathering systems and production facilities vs. $123 million in 1997. In 1998, the company's gas sales increased to 555 million cubic feet per day from 549 million cubic feet per day in 1997. Crude oil sales averaged 29,808 barrels per day in 1998, an increase of 9% over the 1997 production. In 1998, the company replaced 148% of production with proven reserve additions, net of revisions, by spending 163% of cash flow from operations on capital spending. After a volatile year in 1 997, natural gas prices stabilized somewhat in 1998. A modest price increase was experienced in 1997. The company's average plant gate natural gas price increased modestly in 1998 to $1.94 per thousand cubic feet, marking the 3rd consecutive price increase. The company owns an average interest of 10.4% in two straddle plants at Empress, Alberta. The company operates and is a 50% owner of Federated Pipe Lines Ltd. The company is committed to protecting the health and safety of all employees and the public, as well as preserving the quality of the environment
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)
Meson Correlators in Finite Temperature Lattice QCD
De Forcrand, Philippe; Hashimoto, T; Hioki, S; Matsufuru, H; Miyamura, O; Nakamura, A; Takaishi, T; Umeda, T; Stamatescu, I O; CERN. Geneva; Forcrand, Ph. de
2001-01-01
We analyze temporal and spatial meson correlators in quenched lattice QCD at T>0. Below T_c we observe little change in the meson properties as compared with T=0. Above T_c we observe new features: chiral symmetry restoration and signals of plasma formation, but also indication of persisting mesonic (metastable) states and different temporal and spatial masses in the mesonic channels. This suggests a complex picture of QGP in the region 1 - 1.5 T_c.
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.)
Controlling Anderson localization in disordered photonic crystal waveguides
DEFF Research Database (Denmark)
Garcia-Fernández, David; Smolka, Stephan; Stobbe, Søren
2010-01-01
In most experiments on Anderson localization so far, only completely random systems without any long-range correlation between the scattering sites have been used, meaning that the Anderson localized modes cannot be controlled. Strongly confined modes were recently observed in the slow-light regime...... of a disordered photonic crystal waveguide and attributed to Anderson localization. We have tested this hypothesis by measuring the light localization length, ξloc, in a disordered photonic crystal waveguide and checked explicitly the criterion of one dimensional Anderson localization that ξloc is shorter than...... the waveguide length LS. Our measurements demonstrate for the first time the close relation between light localization and density of states, which can be used ultimately for controlling Anderson localized modes....
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)
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)
Neutral B meson flavor tagging
Wilson, R J
2001-01-01
We present an investigation of the use of net charge and kaon identification to tag the flavor of neutral B mesons. The net charge of the neutral B meson decay products is zero if all charged particles are used and slightly non-zero if only undiscriminated hadronic final states are used. The net charge of the kaons alone correctly tags the identity of the neutral meson in at least a third of all decays. We have parametrized the particle identification capability of several techniques, such as dE/dx in time projection chambers, LEP/SLC ring-imaging chambers and an enhanced BaBar DIRC. Using these parametrisations we compare the relative tagging power of each technique to that of an ideal detector. (8 refs).
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)
Ginzburg-Landau expansion in strongly disordered attractive Anderson-Hubbard model
Kuchinskii, E. Z.; Kuleeva, N. A.; Sadovskii, M. V.
2017-07-01
We have studied disordering effects on the coefficients of Ginzburg-Landau expansion in powers of superconducting order parameter in the attractive Anderson-Hubbard model within the generalized DMFT+Σ approximation. We consider the wide region of attractive potentials U from the weak coupling region, where superconductivity is described by BCS model, to the strong coupling region, where the superconducting transition is related with Bose-Einstein condensation (BEC) of compact Cooper pairs formed at temperatures essentially larger than the temperature of superconducting transition, and a wide range of disorder—from weak to strong, where the system is in the vicinity of Anderson transition. In the case of semielliptic bare density of states, disorder's influence upon the coefficients A and B of the square and the fourth power of the order parameter is universal for any value of electron correlation and is related only to the general disorder widening of the bare band (generalized Anderson theorem). Such universality is absent for the gradient term expansion coefficient C. In the usual theory of "dirty" superconductors, the C coefficient drops with the growth of disorder. In the limit of strong disorder in BCS limit, the coefficient C is very sensitive to the effects of Anderson localization, which lead to its further drop with disorder growth up to the region of the Anderson insulator. In the region of BCS-BEC crossover and in BEC limit, the coefficient C and all related physical properties are weakly dependent on disorder. In particular, this leads to relatively weak disorder dependence of both penetration depth and coherence lengths, as well as of related slope of the upper critical magnetic field at superconducting transition, in the region of very strong coupling.
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
Adaptive and self-averaging Thouless-Anderson-Palmer mean-field theory for probabilistic modeling
DEFF Research Database (Denmark)
Opper, Manfred; Winther, Ole
2001-01-01
We develop a generalization of the Thouless-Anderson-Palmer (TAP) mean-field approach of disorder physics. which makes the method applicable to the computation of approximate averages in probabilistic models for real data. In contrast to the conventional TAP approach, where the knowledge of the d...... distributions in the thermodynamic limit. On the other hand, simulations on a real data model demonstrate that the method achieves more accurate predictions as compared to conventional TAP approaches....
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
A light meson translatable template
International Nuclear Information System (INIS)
Allgower, C.E.; Peaslee, D.C.
2002-01-01
Recently surveyed (mass)2 values for I = 0, JPC = 2++ light mesons can be assembled into repeating patterns of 4 states, dubbed 'templates'. Within error, both internal and external template spacings approximate simple multiples of Δm2 ≅ 0.35 GeV2. Hopefully, this feature will be useful in predicting the positions of higher isoscalar 2++ states
Exclusive meson production at COMPASS
Pochodzalla, Josef; Moinester, Murray; Piller, Gunther; Sandacz, Andrzej; Vanderhaeghen, Marc; Pochodzalla, Josef; Mankiewicz, Lech; Moinester, Murray; Piller, Gunther; Sandacz, Andrzej; Vanderhaeghen, Marc
1999-01-01
We explore the feasibility to study exclusive meson production (EMP) in hard muon-proton scattering at the COMPASS experiment. These measurements constrain the off-forward parton distributions (OFPD's) of the proton, which are related to the quark orbital contribution to the proton spin.
Orbitally excited charm - strange mesons
Energy Technology Data Exchange (ETDEWEB)
Kasper, Penelope A. [Illinois Inst. of Technology, Chicago, IL (United States)
1996-05-01
This thesis describes an attempt to measure the properties of mesons containing a charm quark and a strange quark in a state of orbital angular momentum L > 0, and compare these with the predictions of theoretical models based on heavy quark effective theory.
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.
Charm physics: theoretical review
Petrov, Alexey A.
2003-01-01
We review recent developments in charm physics, focusing on the physics of charmed mesons. We discuss charm spectroscopy, decay constants, as well as searches for new physics with charmed mesons. We discuss D0-anti-D0 mixing and CP-violation in charm decays. We also present the modified Nelson plot of charm mixing predictions.
1999-01-01
In 1936, at age 31, Carl David Anderson became the second youngest Nobel laureate for his discovery of antimatter when he observed positrons in a cloud chamber.He is responsible for developing rocket power weapons that were used in World War II.He was born in New York City in 1905 and was educated in Los Angeles. He served for many years as a physics professor at California Institute of Technology. Prior to Oppenheimer, Anderson was offered the job of heading the Los Alamos atomic bomb program but could not assume the role because of family obligations.He was a pioneer in studying cosmic rays
Test of scalar meson structure in {phi} radiative decays
Energy Technology Data Exchange (ETDEWEB)
Kumano, S. [Mainz Univ. (Germany). Inst. fuer Kernphysik
1992-12-01
We show that {phi} radiative decays into scalar mesons [f{sub 0}(975), a{sub 0}(980) {identical_to} S] can provide important clues on the internal structures of these mesons. Radiative decay widths vary widely: B.R. = 10{sup -4}-10{sup -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 {phi} 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 {sigma} meson. We also find that the decay {phi}{yields}S{sub {gamma}}{yields}K{sup 0}K-bar{sup 0}{sub {gamma}} is not strong enough to pose a significant background problem for studying CP violation via {phi}{yields}K{sup 0}K-bar{sup 0} at the {phi} factories. (author).
Cavity quantum electrodynamics in the Anderson-localized regime
DEFF Research Database (Denmark)
Sapienza, Luca; Nielsen, Henri Thyrrestrup; Stobbe, Søren
2010-01-01
We experimentally measure, by means of time-resolved photoluminescence spectroscopy, a 15-fold enhancement of the spontaneous emission decay rate of single semiconductor quantum dots coupled to disorder-induced Anderson-localized modes with efficiencies reaching 94%....
Martin Anderson valis "Joonase lähetamise" / Priit Kuusk
Kuusk, Priit, 1938-
2000-01-01
M. Anderson kommenteeris ameerika muusikaajakirjas "Fanfare" viit talle kõige enam mõju avaldanud heliplaati, sh. R. Tobiase oratooriumi "Joonase lähetamine" CD-plaati (BIS). M. Andersoni huvist eesti muusika vastu
Controlling Anderson localization in disordered photonic crystal waveguides
DEFF Research Database (Denmark)
Garcia-Fernández, David; Smolka, Stephan; Stobbe, Søren
structures [1,2]. Originally proposed for electrons by P. W. Anderson [3], only completely random systems without any long-range correlation between the scattering sites have been used so far, meaning that the Anderson-localized modes cannot be controlled. In disordered photonic crystals, these modes...... are predicted to appear at frequencies in or near a band gap [4] providing a possible way to control Anderson-localized modes. We have tested this hypothesis by measuring the light localization length, ξ, in a disordered photonic crystal waveguide (PCW) as a function of the dispersive slowdown factor of light...... of the waveguide. Our measurements demonstrate for the first time the close relation between light localization and density of states [5], which can be used ultimately for controlling the extension and spectral position of Anderson-localized modes....
Probing the statistical properties of Anderson localization with quantum emitters
DEFF Research Database (Denmark)
Smolka, Stephan; Nielsen, Henri Thyrrestrup; Sapienza, Luca
2011-01-01
Wave propagation in disordered media can be strongly modified by multiple scattering and wave interference. Ultimately, the so-called Anderson-localized regime is reached when the waves become strongly confined in space. So far, Anderson localization of light has been probed in transmission...... experiments by measuring the intensity of an external light source after propagation through a disordered medium. However, discriminating between Anderson localization and losses in these experiments remains a major challenge. In this paper, we present an alternative approach where we use quantum emitters...... embedded in disordered photonic crystal waveguides as light sources. Anderson-localized modes are efficiently excited and the analysis of the photoluminescence spectra allows us to explore their statistical properties, for example the localization length and average loss length. With increasing the amount...
The effect of instanton-induced interaction on P-wave meson spectra ...
Indian Academy of Sciences (India)
physics pp. 75–85. The effect of instanton-induced interaction on P-wave meson spectra in constituent quark model. BHAVYASHRI1, S SARANGI2, GODFREY ... P-wave spectra. PACS Nos 14.40.-n; 14.40.-Aq; 14.40.Ev; 12.39.-Jh. 1. Introduction. Numerous papers have been devoted to the study of meson spectra in the ...
Strong Anderson localization in cold atom quantum quenches
Micklitz, T.; Müller, C. A.; Altland, A.
2013-01-01
Signatures of strong Anderson localization in the momentum distribution of a cold atom cloud after a quantum quench are studied. We consider a quasi one-dimensional cloud initially prepared in a well defined momentum state, and expanding for some time in a disorder speckle potential. Anderson localization leads to a formation of a coherence peak in the \\emph{forward} scattering direction (as opposed to the common weak localization backscattering peak). We present a microscopic, and fully time...
Controlling Anderson localization in disordered photonic crystal waveguides
DEFF Research Database (Denmark)
Smolka, Stephan; Garcia, Pedro D.; Lodahl, Peter
2010-01-01
We prove Anderson localization in the slow-light regime of a photonic crystal waveguide by measuring the ensemble-averaged localization length which is controlled by the dispersion of the disordered photonic crystal waveguide.......We prove Anderson localization in the slow-light regime of a photonic crystal waveguide by measuring the ensemble-averaged localization length which is controlled by the dispersion of the disordered photonic crystal waveguide....
Delta, iota and other meson spectroscopies
International Nuclear Information System (INIS)
Lipkin, H.J.
1986-05-01
This talk is given from the point of view of an experimentalist. Meson spectroscopy in the 1 to 3 GeV region is interesting because experiments exploring this region, in particular radiative psi decay, have found a rich structure of resonances too complicated to unravel with any one experiment, and not easily interpreted with any one theoretical model. None of the theoretical calculations predicting all kinds of interesting and exotic objects in this region is very convincing or reliable. Additional input from anti pp annihilation can be very useful in helping to find the answers to the following open questions: what exactly is this spectrum, what are the masses and quantum numbers of the resonances, as determined from analysis of data without theoretical prejudices; how is this spectrum described by QCD, is there evidence for new kinds of states like glue-balls, hybrids, axions, Higgses or multiquark exotics, and is there any evidence for new physics beyond QCD. 20 refs
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
D meson lifetimes within the Heavy Quark Expansion
Lenz, Alexander
2013-01-01
Even if new data indicates that direct CP violation in D meson decays is compatible with the standard model expectation, it triggered a lot of interest and charm phenomenology will remain an essential part of new physics searches due to the unique role as a probe for FCNC among up-type quarks. Charm physics poses considerable theoretical challenges, because the charm mass is neither light nor truly heavy. The Heavy Quark Expansion (HQE) provides a perturbative expansion in the inverse heavy quark mass for inclusive rates. It proved to be very successful in the B sector, yet its validity for charm decays has often been questioned. We present results of a HQE study of D meson lifetimes including NLO QCD and subleading 1/m_c corrections. We find good agreement with experimental data, however with huge hadronic uncertainties due to missing lattice input for hadronic matrix elements.
International Nuclear Information System (INIS)
Feldman, G.J.
1977-01-01
A review is given of the nonleptonic decays of D mesons. Included are measurements of the psi(3772), the accurate determination of D masses and their consequences, and inclusive measurements and tagged events. It is noted that the distinction between the above designated events is that in the former one detects a D decay and ignores the remainder of the event, while in the tagged events a D decay is detected and also the remainder of the event is studied. 39 references
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.)
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.
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 properties in magnetized quark matter
Wang, Ziyue; Zhuang, Pengfei
2018-02-01
We study neutral and charged meson properties in the magnetic field. Taking the bosonization method in a two-flavor Nambu-Jona-Lasinio model, we derive effective meson Lagrangian density with minimal coupling to the magnetic field, by employing derivative expansion for both the meson fields and Schwinger phases. We extract from the effective Lagrangian density the meson curvature, pole and screening masses. As the only Goldstone mode, the neutral pion controls the thermodynamics of the system and propagates the long range quark interaction. The magnetic field breaks down the space symmetry, and the quark interaction region changes from a sphere in vacuum to a ellipsoid in magnetic field.
International Nuclear Information System (INIS)
Gajewski, W.; Swiecki, M.
1975-01-01
This paper is devoted to the description of the present status of our knowledge about π meson elastic form factor. In the first section there is given a definition of the form factor on the basis of electromagnetic interactions, and its extension to weak and strong interactions. Next, there are reviewed theoretical models, which on the assumption of analyticity predict features of π meson form factor. In the last sections the results of experimental investigaton of π meson form factor are described with the stress on the results of the recent experiment made on Serpukhov accelerator in order to measure the π meson electromagnetic radius. (author)
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
Investigation of Anderson lattice behavior in Yb1-xLuxAl3
International Nuclear Information System (INIS)
Bauer, E.D.; Booth, C.H.; Lawrence, J.M.; Hundley, M.F.; Sarrao, J.L.; Thompson, J.D.; Riseborough, P.S.; Ebihara, T.
2003-01-01
Measurements of magnetic susceptibility χ(T), specific heat C(T), Hall coefficient R H (T), and Yb valence ν = 2 + n f [f-occupation number n f (T) determined from Yb L 3 x-ray absorption measurements] were carried out on single crystals of Yb 1-x Lu x Al 3 . The low temperature anomalies observed in χ(T) and C(T) corresponding to an energy scale T coh ∼ 40 K in the intermediate valence, Kondo lattice compound YbAl 3 are suppressed by Lu concentrations as small as 5% suggesting these low-T anomalies are extremely sensitive to disorder and, therefore, are a true coherence effect. By comparing the temperature dependence of various physical quantities to the predictions of the Anderson Impurity Model, the slow crossover behavior observed in YbAl 3 , in which the data evolve from a low-temperature coherent, Fermi-liquid regime to a high temperature local moment regime more gradually than predicted by the Anderson Impurity Model, appears to evolve to fast crossover behavior at x ∼ 0.7 where the evolution is more rapid than predicted. These two phenomena found in Yb 1-x Lu x Al 3 , i.e., the low-T anomalies and the slow/fast crossover behavior are discussed in relation to recent theories of the Anderson lattice
Direct observation of Anderson localization of matter waves in a controlled disorder.
Billy, Juliette; Josse, Vincent; Zuo, Zhanchun; Bernard, Alain; Hambrecht, Ben; Lugan, Pierre; Clément, David; Sanchez-Palencia, Laurent; Bouyer, Philippe; Aspect, Alain
2008-06-12
In 1958, Anderson predicted the localization of electronic wavefunctions in disordered crystals and the resulting absence of diffusion. It is now recognized that Anderson localization is ubiquitous in wave physics because it originates from the interference between multiple scattering paths. Experimentally, localization has been reported for light waves, microwaves, sound waves and electron gases. However, there has been no direct observation of exponential spatial localization of matter waves of any type. Here we observe exponential localization of a Bose-Einstein condensate released into a one-dimensional waveguide in the presence of a controlled disorder created by laser speckle. We operate in a regime of pure Anderson localization, that is, with weak disorder-such that localization results from many quantum reflections of low amplitude-and an atomic density low enough to render interactions negligible. We directly image the atomic density profiles as a function of time, and find that weak disorder can stop the expansion and lead to the formation of a stationary, exponentially localized wavefunction-a direct signature of Anderson localization. We extract the localization length by fitting the exponential wings of the profiles, and compare it to theoretical calculations. The power spectrum of the one-dimensional speckle potentials has a high spatial frequency cutoff, causing exponential localization to occur only when the de Broglie wavelengths of the atoms in the expanding condensate are greater than an effective mobility edge corresponding to that cutoff. In the opposite case, we find that the density profiles decay algebraically, as predicted in ref. 13. The method presented here can be extended to localization of atomic quantum gases in higher dimensions, and with controlled interactions.
Relative rates of B meson decays into psi(2S) and J/psi mesons.ptonic decay channel
Czech Academy of Sciences Publication Activity Database
Abazov, V. M.; Abbott, B.; Abolins, M.; Kupčo, Alexander; Lokajíček, Miloš
2009-01-01
Roč. 79, č. 11 (2009), 111102/1-111102/6 ISSN 1550-7998 R&D Projects: GA MŠk LC527; GA MŠk LA08047 Institutional research plan: CEZ:AV0Z10100502 Keywords : tevatron * D0 * B meson * muon Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.922, year: 2009 http://link.aps.org/doi/10.1103/PhysRevD.79.111102
Meson spectroscopy with COMPASS
Nerling, Frank
2011-01-01
The COMPASS fixed-target experiment at CERN SPS is dedicated to the study of hadron structure and dynamics. In the physics programme using hadron beams, the focus is on the detection of new states, in particular the search for $J^{PC}$ exotic states and glueballs. After a short pilot run in 2004 (190 GeV/c negative pion beam, lead target), we started our hadron spectroscopy programme in 2008 by collecting an unprecedented statistics with a negative hadron beam (190 GeV/c) on a liquid hydrogen target. A similar amount of data with positive hadron beam (190 GeV/c) has been taken in 2009, as well as some additional data with negative beam on nuclear targets. The spectrometer features a large angular acceptance and high momentum resolution and also good coverage by electromagnetic calorimetry, crucial for the detection of final states involving $\\pi^0$ or $\\eta$. A first important result is the observation of a significant $J^{PC}$ spin exotic signal consistent with the disputed $\\pi_1(1600)$ in the pilot run dat...
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
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
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)
Experimental evidence for hadroproduction of exotic mesons
Energy Technology Data Exchange (ETDEWEB)
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.
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
Meson theory and nuclear matter
International Nuclear Information System (INIS)
Skyrme, T.H.R.
1994-01-01
An attempt is made to justify the use of the concept of a 'mesic fluid' in connection with the structure of nuclear matter. A transformation is made of the usual symmetric pseudo-scalar meson theory to bring into evidence certain saturation properties, which provide a natural basis for the use of a 'self-consistent' field in the discussion of nuclear structure. Fluctuations about this semi-classical saturated state will give rise to residual interparticle forces within the nucleus, and are also briefly considered in relation to electromagnetic interactions. (author). 5 refs
Mohler, Daniel; Woloshyn, R. M.
2010-01-01
Preliminary results are presented for the spectrum of D_s mesons using the 2+1 flavor Clover-Wilson configurations made available by the PACS-CS collaboration. For the heavy quark, the Fermilab method is employed and we report on the tuning of the charm-quark hopping parameter. As our main focus, we present initial results for the spectrum of P-wave states, where previous results have been mostly from quenched calculations. As a cross-check, some calculations of the charmonium spectrum are al...
Multihadron decays of new mesons
International Nuclear Information System (INIS)
Koller, K.; Walsh, T.F.
1975-12-01
We discuss the hadronic decays of the new I = 0 mesons seen in e + e - , PSI-3,105 or PSI-3,695 with G = - and CHI or X with G = +. We present some isospin inequalities for I = 0 pure pionic final states, and a discussion of anti-K K and ETA-549, ETA-958 fractions. We also present a statistical model analysis of pion final states, and conclude that a large fraction of hadronic PSI-3,105 decays contain something besides pions and anti-K K probably ETA-549 and ETA-958, possibly radiative modes. (orig.) [de
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
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
Strong Anderson localization in cold atom quantum quenches.
Micklitz, T; Müller, C A; Altland, A
2014-03-21
Signatures of Anderson localization in the momentum distribution of a cold atom cloud after a quantum quench are studied. We consider a quasi-one-dimensional cloud initially prepared in a well-defined momentum state, and expanding for some time in a disorder speckle potential. Quantum interference generates a peak in the forward scattering amplitude which, unlike the common weak localization backscattering peak, is a signature of strong Anderson localization. We present a nonperturbative, and fully time resolved description of the phenomenon, covering the entire diffusion-to-localization crossover. Our results should be observable by present day experiments.
DEFF Research Database (Denmark)
Jacobsen, Finn
2011-01-01
The effect known as ‘weak Anderson localisation’, ‘coherent backscattering’ or ‘enhanced backscattering’ is a physical phenomenon that occurs in random systems, e.g., disordered media and linear wave systems, including reverberation rooms: the mean square response is increased at the drive point...... position it is obviously very difficult to measure the effect directly. The ‘concentration factor’ is usually assumed to be 2, and the ‘modal kurtosis’ is assumed to be 3. This paper presents the results of an indirect experimental estimation of these two parameters, and discusses implications...... for the uncertainty of sound power measurements....
DEFF Research Database (Denmark)
Jacobsen, Finn
2011-01-01
The effect known as ‘weak Anderson localisation’, ‘coherent backscattering’ or ‘enhanced backscattering’ is a physical phenomenon that occurs in random systems, e.g., disordered media and linear wave systems, including reverberation rooms: the mean square response is increased at the drive point....... In a reverberation room this means that one can expect an increase of the reverberant sound field at the position of the source that generates the sound field. This affects the sound power output of the source and is therefore of practical concern. However, because of the stronger direct sound field at the source...... for the uncertainty of sound power measurements....
Role of Higg's mesons in the violation of muon number
International Nuclear Information System (INIS)
Dicus, D.A.; Teplitz, V.L.
1977-02-01
The branching ratio for the process μ → eγ is calculated by assuming that the couplings of both the scalar (Higg's) mesons and the gauge mesons to heavy leptons violate muon number conservation. When the Higg's mesons are somewhat lighter than the gauge mesons their contribution to μ → eγ is the more important one
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
GlueX: Meson Spectroscopy in Photoproduction
Energy Technology Data Exchange (ETDEWEB)
Salgado, Carlos [Norfolk State University, JLAB; Smith, Elton S. [JLAB
2014-03-01
The goal of the GlueX experiment \\cite{gluex} is to provide crucial data to help understand the soft gluonic fields responsible for binding quarks in hadrons. Hybrid mesons, and in particular exotic hybrid mesons, provide the ideal laboratory for testing QCD in the confinement regime since these mesons explicitly manifest the gluonic degrees of freedom. Photoproduction is expected to be effective in producing exotic hybrids but there is little data on the photoproduction of light mesons. GlueX will use the new 12-GeV electron beam at Jefferson Lab to produce a 9-GeV beam of linearly polarized photons using the technique of coherent bremsstrahlung. A solenoid-based hermetic detector is under construction, which will be used to collect data on meson production and decays. These data will also be used to study the spectrum of conventional mesons, including the poorly understood excited vector mesons. This talk will give an update on the experiment as well as describe theoretical developments \\cite{Dudek:2011bn} to help understand how these data can provide insights into the fundamental theory of strong interactions.
Exotic hybrid mesons in hard electroproduction
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 ...
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.
Meson Form Factors and Deep Exclusive Meson Production Experiments
Energy Technology Data Exchange (ETDEWEB)
Horn, Tanja [The Catholic Univ. of America, Washington, DC (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2017-05-01
Pion and kaon electroproduction data play a unique role in Nature and our understanding of them is essential for explaining hadron structure. Precision longitudinaltransverse separated pion and kaon cross sections are of particular interest. They allow for the extraction of meson form factors and validation of understanding of hard exclusive and semi-inclusive reactions (π+, K+, π0, γ) towards 3D hadron imaging and potential future flavor decomposition. We review recent data and present prospects for deep exclusive pion and kaon electroproduction at the 12 GeV Jefferson Lab including the prospects to use projected charged- and neutral pion data to further determine the spin, charge-parity and flavor of GPDs, including the helicity-flip GPDs.
Spectral Approach to Anderson Localization in a Disordered 2D Complex Plasma Crystal
Kostadinova, Eva; Liaw, Constanze; Matthews, Lorin; Busse, Kyle; Hyde, Truell
2016-10-01
In condensed matter, a crystal without impurities acts like a perfect conductor for a travelling wave-particle. As the level of impurities reaches a critical value, the resistance in the crystal increases and the travelling wave-particle experiences a transition from an extended to a localized state, which is called Anderson localization. Due to its wide applicability, the subject of Anderson localization has grown into a rich field in both physics and mathematics. Here, we introduce the mathematics behind the spectral approach to localization in infinite disordered systems and provide physical interpretation in context of both quantum mechanics and classical physics. We argue that the spectral analysis is an important contribution to localization theory since it avoids issues related to the use of boundary conditions, scaling, and perturbation. To test accuracy and applicability we apply the spectral approach to the case of a 2D hexagonal complex plasma crystal used as a macroscopic analog for a graphene-like medium. Complex plasma crystals exhibit characteristic distance and time scales, which are easily observable by video microscopy. As such, these strongly coupled many-particle systems are ideal for the study of localization phenomena. The goal of this research is to both expand the spectral method into the classical regime and show the potential of complex plasma as a macroscopic tool for localization experiments. NSF / DOE funding is gratefully acknowledged - PHY1414523 & PHY1262031.
Quantum criticality of quasi one-dimensional topological Anderson insulators
Altland, A.; Bagrets, D.; Fritz, L.; Kamenev, A.; Schmiedt, H.
2014-01-01
We present an analytic theory of quantum criticality in the quasi one-dimensional topological Anderson insulators of class AIII and BDI. We describe the systems in terms of two parameters (g,χ) representing localization and topological properties, respectively. Surfaces of half-integer valued χ
Spectra of Anderson type models with decaying randomness
Indian Academy of Sciences (India)
Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45
There have been but few models in higher dimensional random operators of the Anderson model type in which presence ... The models we consider in this paper are related to the discrete Laplacian ( u)(n) = ∑. |i|=1 u(n + i) on l2( ν). .... identically distributed real valued random variables with distribution µ. The operator H0.
Coordination of lanthanide cation to an Anderson type ...
Indian Academy of Sciences (India)
Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 5. Coordination of lanthanide cation to an Anderson type polyoxometalate anion ... and spectroscopy. Vaddypally Shivaiah Tanmay Chatterjee Samar K Das. Special issue on Chemical Crystallography Volume 126 Issue 5 September 2014 pp 1525-1533 ...
Interpolation solution of the single-impurity Anderson model
International Nuclear Information System (INIS)
Kuzemsky, A.L.
1990-10-01
The dynamical properties of the single-impurity Anderson model (SIAM) is studied using a novel Irreducible Green's Function method (IGF). The new solution for one-particle GF interpolating between the strong and weak correlation limits is obtained. The unified concept of relevant mean-field renormalizations is indispensable for strong correlation limit. (author). 21 refs
Eigenfunction statistics for Anderson model with Hölder continuous ...
Indian Academy of Sciences (India)
continuous (0 < α ≤ 1) single site distribution. In localized regime, we study the distri- bution of eigenfunctions in space and energy simultaneously. In a certain scaling limit, we prove limit points are Poisson. Keywords. Anderson model; Hölder continuous measure; Poisson statistics. 2010 Mathematics Subject Classification ...
Controlling Anderson localization in disordered photonic crystal waveguides
DEFF Research Database (Denmark)
Garcia-Fernández, David; Smolka, Stephan; Stobbe, Søren
2010-01-01
are predicted to appear at frequencies in or near a band gap [4] providing a possible way to control Anderson-localized modes. We have tested this hypothesis by measuring the light localization length, ξ, in a disordered photonic crystal waveguide (PCW) as a function of the dispersive slowdown factor of light...
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)
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
From the {psi} to charmed mesons
Energy Technology Data Exchange (ETDEWEB)
Goldhaber, G. [Lawrence Berkeley Lab., CA (United States)]|[Univ. of California, Berkeley, CA (United States). Center for Particle Astrophysics
1994-11-01
This talk deals with the author`s recollections about the discoveries of the J/{psi} the {psi}{prime} as well as psion spectroscopy and charmed mesons. He gives a chronology for the {psi} and {psi}{prime} discoveries. He also discusses the events which led to the charmed meson discovery as well as detailed discussions on the proof that the resonance observed in the K{sup {minus}} {pi}{sup +} system, at 1,865 MeV, was indeed the predicted charmed meson.
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.)
Spectator interactions in the Drell-Yan process: meson + meson -> lepton pair + anything
Energy Technology Data Exchange (ETDEWEB)
Lindsay, W.W. (Southampton Univ. (UK). Dept. of Physics)
1984-01-16
A previous calculation, in the Feynman gauge, demonstrating the cancellation (up to two-loop order) of 'long-distance', non-factorizing contributions, to the Drell-Yan cross section for the process: quark + meson -> lepton pair + anything, is extended to include the process: meson + meson -> lepton pair + anything. Again, although non-factorizing terms arise, when contributions from all diagrams are summed, they cancel.
Spectator interactions in the Drell-Yan process: meson + meson -> lepton pair + anything
International Nuclear Information System (INIS)
Lindsay, W.W.
1984-01-01
A previous calculation, in the Feynman gauge, demonstrating the cancellation (up to two-loop order) of 'long-distance', non-factorizing contributions, to the Drell-Yan cross section for the process: quark + meson -> lepton pair + anything, is extended to include the process: meson + meson -> lepton pair + anything. Again, although non-factorizing terms arise, when contributions from all diagrams are summed, they cancel. (orig.)
Brambila, Danilo
2012-01-01
We have theoretically studied Anderson localization in a 2D+1 nonlinear kicked rotor model. The system shows a very rich dynamical behavior, where the Anderson localization is suppressed and soliton wave-particles undergo a superdiffusive motion.
Elliott, Perry; Baker, Robert; Pasquale, Ferdinando; Quarta, Giovanni; Ebrahim, Hatim; Mehta, Atul B.; Hughes, Derralynn A.; Anastasakis, Aristides; Autore, Camillo; Musumeci, Maria Beatrice; Frenneaux, Michael; Gimeno, Juan; Tiina, Heliö; Kuusisto, Johanna; Aalto-Setäla, Katriina; McKeown, Pascal; Monserrat, Lorenzo; Fernandez, Xusto; Pacileo, Giuseppe; Limongelli, Giuseppe; Rapezzi, Claudio; Biagini, Elena; ten Cate, Folkert J.; Wilde, Arthur A. M.; Pinto, Yigal M.; Christiaans, Imke; Zachara, Elisabetta
2011-01-01
The prevalence of Anderson-Fabry disease (AFD) in patients presenting with unexplained left ventricular hypertrophy (LVH) is controversial. The aim of this study was to determine the prevalence of AFD in a large, consecutive cohort of patients with hypertrophic cardiomyopathy (HCM) using rapid
Czech Academy of Sciences Publication Activity Database
Kaluža, Luděk; Palcheva, R.; Spojakina, A.; Jirátová, Květa; Tyuliev, G.
2012-01-01
Roč. 42, SI (2012), s. 873-884 E-ISSN 1877-7058. [International Congress of Chemical and Process Engineering CHISA 2012 and 15th Conference PRES 2012 /20./. Prague, 25.08.2012-29.08.2012] R&D Projects: GA ČR GAP106/11/0902 Institutional support: RVO:67985858 Keywords : NiMo/γ-Al2O3 * anderson heteropolymolybdate * additives Subject RIV: CF - Physical ; Theoretical Chemistry
2010-06-16
... Employment and Training Administration Plastic Omnium Automotive Exteriors, LLC, Anderson, SC; Plastic Omnium... Assistance on March 18, 2010, applicable to workers of Plastic Omnium Automotive Exteriors, LLC, Anderson... have occurred involving workers in support of the Anderson, South Carolina location of Plastic Omnium...
Meson's correlation functions in a nuclear medium
Directory of Open Access Journals (Sweden)
Chanyong Park
2016-09-01
Full Text Available We investigate meson's spectrum, decay constant and form factor in a nuclear medium through holographic two- and three-point correlation functions. To describe a nuclear medium composed of protons and neutrons, we consider a hard wall model on the thermal charged AdS geometry and show that due to the isospin interaction with a nuclear medium, there exist splittings of the meson's spectrum, decay constant and form factor relying on the isospin charge. In addition, we show that the ρ-meson's form factor describing an interaction with pseudoscalar fluctuation decreases when the nuclear density increases, while the interaction with a longitudinal part of an axial vector meson increases.
Kaons in flavor tagged B meson decays
International Nuclear Information System (INIS)
Cronstroem, H.I.
1991-01-01
Using the ARGUS detector at the e + e - storage ring DORIS II, measurements of multiplicities of pseudoscalar kaons, of K*(892) and of φ(1020) in B meson decays have been performed through studies of angular and charge correlations between the above particles and high momentum leptons produced in semileptonic B decays. The method has made it possible to measure the multiplicities separately for B-mesons and anti-B-mesons. The excess of like charge lepton-kaon pairs over opposite charge pairs in semileptonic decays was used for estimating the ratio of charmed decays over all decays, and thus also the fraction of charmless decays. A search for an excess of fast neutral kaons from rare B decays was also made. All the results obtained support the assumption that almost all B mesons decay through b → c transitions into charmed hadrons. (66 refs.)
Hybrid mesons: old prejudices and new spectroscopy
International Nuclear Information System (INIS)
Kalashnikova, Yu.S.
1997-01-01
The models for hybrid mesons are discussed, in which the gluonic excitations manifest themselves as the vibrations of the quark-antiquark QCD string. The predictions for the spectra, decays and mixing with hadronic channels are presented. (orig.)
Vector mesons in meson-baryon scattering and large-Nc 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 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
Quark spin content of vector mesons
International Nuclear Information System (INIS)
Bander, M.
1991-01-01
η' dominance of form factors of the topological QCD current leads to an expression for the portion of the spin of the light vector mesons that is due to quarks. Vector dominance of the radiative decays of the η' is used to estimate the couplings of this meson to the vector ones. This results in the conclusion that only around 30% of the spin of these particles is due to quarks. Possible interpretations of this result are presented
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.
Meson and baryon spectroscopy on the lattice
Energy Technology Data Exchange (ETDEWEB)
David Richards
2010-12-01
Recent progress at understanding the excited state spectrum of mesons and baryons is described. I begin by outlining the application of the variational method to compute the spectrum, and the program of anisotropic clover lattice generation designed for hadron spectroscopy. I present results for the excited meson spectrum, with continuum quantum numbers of the states clearly delineated. I conclude with recent results for the low lying baryon spectrum, and the prospects for future calculations.
Oscillations of neutral B mesons systems
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
Hadron electromagnetic structure and heavy vector mesons
International Nuclear Information System (INIS)
Zovko, N.
1975-01-01
The present status of knowledge on hadron form factors is summarized. The extended vector meson dominance model, supplemented with additional dynamical constraints, provides the most natural simple scheme which is able to account for all basic features of analytic form factors. The model discussed connects the asymptotics of form factors and the characteristics of heavy vector mesons with a large amount of data on form factors. Also some other recent models are touched peripherally
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
Vector meson production in ultra-peripheral collisions
Thomas, James O.
Charged ions moving at relativistic speeds generate strong electromagnetic fields (E/M) that, at regions outside the source (important when the E/M sources are nuclei), behave like the fields from a beam of real photons. These equivalent, or virtual photons, can induce an excitation in another nucleus as the source flies by. Existing theories attempt to explain such processes and predict their outcome. One way to study such Ultra-Peripheral Collisions (UPCs) is to simulate them using a Monte-Carlo Multi-Collisional (MCMC) model based on nucleon degrees of freedom. The CRISP (acronym for Collaboration Rio-Illheus-Sao Paulo) model is one such theory. It is basically at the stage of a well-documented software package that implements the MCMC. This model has successfully predicted observables, such as neutron multiplicity, from central collisions and also in UPCs with relativistic heavy ions. However, the photoproduction of vector mesons has only recently been added to the CRISP model. A completely different approach to study UPCs focuses on the role of Parton Distribution Functions (PDFs) in the excitation process. Here, instead of nucleons, the degrees of freedom are quarks and gluons (generically known as partons). Several distinct PDFs exist in the literature and are continually being updated. This work used experimental results released from the ALICE collaboration at the Large Hadron Collider (LHC) facility located at the international particle physics laboratory CERN in Switzerland. Our outputs from the CRISP model, and from the sub-nucleon degrees of freedom model, were photonuclear cross sections for vector meson production. A comparison of our results with the experimental data allowed us to constrain different PDFs, as well as the effect of multiple collisions on the production of mesons with nucleons in the final channel. Upon completion of the calculations, it was seen that the hadronic models could accurately predict the production of the J/psi meson, but
Studying Online Behavior: Comment on Anderson et al. 2014
Directory of Open Access Journals (Sweden)
Kevin Lewis
2015-01-01
Full Text Available As social scientists increasingly employ data from online sources, it is important that we acknowledge both the advantages an limitations of this research. The latter have received comparatively little public attention. In this comment, I argue that a recent article by Anderson and colleagues: 1 inadequately describes the study sample; 2 inadequately describes how the website operates; and 3 inadequately develops the paper’s central measures — such that it is difficult to evaluate the generalizability, veracity, and importance of their claims and impossible to replicate their findings. These limitations are not unique to the Anderson et al. article; rather, they point to a set of concerns that all researchers in this growing and important line of study need to address if our work is to have enduring impact.
New supersymmetric CP-violating contribution to neutral meson mixing
International Nuclear Information System (INIS)
Worah, M.P.
1996-01-01
We study the contribution to flavor-changing neutral current processes from box diagrams with light Higgsinos and squarks. Starting with just the Cabibbo-Kobayashi-Maskawa (CKM) phase, we find contributions to the K 0 and B 0 meson mass matrices that are out of phase with the standard model contributions in the case of substantial mixing between the up-type squarks. This difference in phase could be large enough to be detected at the proposed B factories, with interesting implications for the unitarity triangle of CKM matrix elements. copyright 1996 The American Physical Society
Composite Vector Mesons from QCD to the Little Higgs
Energy Technology Data Exchange (ETDEWEB)
Piai, Maurizio
2004-05-24
We review how the {rho} meson can be modeled in an effective theory and discuss the implications of applying this approach to heavier spin-one resonances. Georgi's vector limit is explored, and its relationship to locality in a deconstructed extra-dimension is discussed. We then apply the formalism for {rho}'s to strongly coupled theories of electroweak symmetry breaking, studying the lightest spin-one techni-{rho}s resonances. Understanding these new particles in Little Higgs models can shed light on previously incalculable, ultraviolet sensitive physics, including the mass of the Higgs boson.
Wegner Estimate and Anderson Localization for Random Magnetic Fields
Erdős, László; Hasler, David
2012-01-01
We consider a two dimensional magnetic Schrödinger operator with a spatially stationary random magnetic field. We assume that the magnetic field has a positive lower bound and that it has Fourier modes on arbitrarily short scales. We prove the Wegner estimate at arbitrary energy, i.e. we show that the averaged density of states is finite throughout the whole spectrum. We also prove Anderson localization at the bottom of the spectrum.
Experimental Test of Universality of the Anderson Transition
Lopez, Matthias; Clément, Jean-François; Szriftgiser, Pascal; Garreau, Jean Claude; Delande, Dominique
2012-03-01
We experimentally test the universality of the Anderson three dimensional metal-insulator transition, using a quasiperiodic atomic kicked rotor. Nine sets of parameters controlling the microscopic details have been tested. Our observation indicates that the transition is of second order, with a critical exponent independent of the microscopic details; the average value 1.63±0.05 agrees very well with the numerically predicted value ν=1.58.
Dynamic greedy algorithms for the Edwards-Anderson model
Schnabel, Stefan; Janke, Wolfhard
2017-11-01
To provide a novel tool for the investigation of the energy landscape of the Edwards-Anderson spin-glass model we introduce an algorithm that allows an efficient execution of a greedy optimization based on data from a previously performed optimization for a similar configuration. As an application we show how the technique can be used to perform higher-order greedy optimizations and simulated annealing searches with improved performance.
Effect of Anderson magnetic impurities on superconducting alloys
International Nuclear Information System (INIS)
Ahmed, M.; Rashid, R.I.M.A.
1983-06-01
A model which consists of a BCS Hamiltonian and a periodic Anderson Hamiltonian for a lattice of magnetic ions is studied using the Green functions equation of motion method. It is found that the Cooper pairing on the site-localized magnetic electrons with antiferromagnetic coupling is capable of destroying superconductivity at a lower critical temperature and thus predicting a reentrant behaviour of the superconducting transition temperature. (author)
Nuclear liability and the Price--Anderson Act
International Nuclear Information System (INIS)
Wilson, R.
1977-01-01
The Price-Anderson Act is viewed as meeting public needs in a unique and responsible way, reflecting the far-sightedness of those involved in the early development of nuclear power who saw the importance of building safety into each step of the program. An extension of the Act is advised as a first step in recognizing that many potential and real disasters (e.g., dam breaks, floods, etc.) are man-made rather than ''Acts of God''. Rather than abolish the Price-Anderson Act because it is unique, the case is made for extending it to cover these other situations. Provisions of the Act are examined in terms of the role of negligence in nuclear accidents, and the conclusion is reached that public concern for reactor safety should not be affected. Limited assets on the part of insurers and insurance pools have made government involvement important but not a real subsidy because of high premiums. Premiums in the new amendment are paid retroactively when there is an accident, which relieves the problem of anticipating what premiums may be needed in the future. This limits government liability and, combined with the waiver of defenses against liability, offers better protection for the public. Recommendations for allowing tort law to operate above the $560 million Price-Anderson limits are criticized, and a counter proposal is made for reassessing the figure at an appropriate limit and extending insurance to competitive industries
MD Anderson's Population Health Approaches to Cancer Prevention.
Foxhall, Lewis; Moreno, Mark; Hawk, Ernest
2018-02-01
Texas's size and unique population demographics present challenges to addressing the state's cancer burden. The University of Texas MD Anderson Cancer Center is one of 69 National Cancer Institute-designated cancer centers across the United States. While these centers traditionally have focused on research, education and training, and providing research-driven patient care, they are in a unique position to collaboratively advance population health through cancer control. Unlike the traditional academic model of a three-legged stool representing research, education, and patient care, MD Anderson's mission includes a fourth leg that incorporates population health approaches. MD Anderson has leveraged state- and national-level data and freely available resources to develop population-health priorities and a set of evidence-based actions across policy, public and professional education, and community-based clinical service domains to address these priorities. Population health approaches complement dissemination and implementation research and treatment, and will be increasingly needed to address the growing cancer burden in Texas and the nation.
Time of Anderson-Fabry Disease Detection and Cardiovascular Presentation
Directory of Open Access Journals (Sweden)
K. Selthofer-Relatic
2018-01-01
Full Text Available Background. Anderson-Fabry disease is an X-linked inherited disease, which manifests in a different manner depending on gender and genotype. Making a working diagnosis of Anderson-Fabry disease is difficult because of several reasons: (a that it is a multiorgan disease with wide variety of phenotypes, (b different timelines of presentation, (c gender differences, and (d possible coexistence with other comorbidities. Late-onset/cardiac type of presentation with minimal involvement of other organs can additionally make diagnosis difficult. Aim. To describe different cardiac manifestations at different time points in the course of the disease: (1 72-year-old female (echocardiography detection, heterozygote, significant left and mild right ventricular hypertrophy; (2 62-year-old male (echocardiography detection, hemizygote, left ventricular hypertrophy, implanted cardiac pacemaker, a performed percutaneous coronary intervention after myocardial infarction, degenerative medium degree aortic valve stenosis; (3 45-year-old female (asymptomatic/family screening, heterozygote, thickened mitral papillary muscle, mild left ventricular hypertrophy, first degree diastolic dysfunction; and (4 75-year-old female (symptomatic/family screening, heterozygote, cardiomyopathy with reduced left ventricular ejection fraction after heart surgery (mitral valve annuloplasty and plastic repair of the tricuspid valve. Conclusion. All patients have Anderson-Fabry disease but with different clinical presentations depending on the gender, the type of mutation, and the time of detection. All these features can make the patients’ profiles unique and delay the time of detection.
Interplay of quark and meson degrees of freedom in a near-threshold resonance
Energy Technology Data Exchange (ETDEWEB)
Baru, V. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Forschungszentrum Juelich, Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Juelich (Germany); Hanhart, C. [Forschungszentrum Juelich, Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Juelich (Germany); Kalashnikova, Yu.S.; Kudryavtsev, A.E.; Nefediev, A.V. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)
2010-04-15
We investigate the interplay of quark and meson degrees of freedom in a physical state representing a near-threshold resonance for the case of a single continuum channel. We demonstrate that such a near-threshold resonance may possess quite peculiar properties if both quark and meson dynamics generate weakly coupled near-threshold poles in the S -matrix. In particular, the scattering t -matrix may possess zeros in this case. We also discuss possible implications for production reactions as well as studies within lattice QCD. (orig.)
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.
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)
Li, Hai-hong; Shao, Feng-lan; Song, Jun
2018-01-01
We study the multiplicity fluctuation and correlation of identified mesons and baryons formed at hadronization by the quark combination mechanism in the context of ultra-relativistic heavy-ion collisions. Based on the statistical method of free quark combination, we derive the two-hadron multiplicity correlations, including meson-meson and meson-baryon correlations, and take the effects of quark number fluctuation at hadronization into account by a Taylor expansion method. After including the decay contributions, we calculate the dynamical fluctuation observable {ν }{dyn} for {{K}}{{π }}, {{p}}{{π }} and Kp pairs and discuss what underlying physics can be obtained by comparing with data from Pb-Pb collisions at \\sqrt{{s}{NN}}=2.76 {TeV} and simulations from the HIJING and AMPT event generators. Supported by National Natural Science Foundation of China (11575100)
Separate T, CP, CPT Asymmetries in Neutral Meson Transitions
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.
Photo- and electroproduction of strange mesons:from elementary process to hypernuclei
Czech Academy of Sciences Publication Activity Database
Sotona, Miloslav
2000-01-01
Roč. 50, - (2000), s. 49-68 ISSN 0011-4626. [TAPS Workshop /5./ "Electromagnetic and Mesonic Probesof Nuclear Matter". Prague, 04.09.1999-08.09.1999] Institutional research plan: CEZ:AV0Z1048901 Subject RIV: BG - Nuclear , Atomic and Molecular Physics, Colliders Impact factor: 0.298, year: 2000
Dipole model for double meson production in two-photon interactions at high energies
Energy Technology Data Exchange (ETDEWEB)
Goncalves, V.P. [Universidade Federal de Pelotas, Instituto de Fisica e Matematica, Caixa Postal 354, Pelotas, RS (Brazil); Machado, M.V.T. [Universidade Federal do Pampa, Centro de Ciencias Exatas e Tecnologicas, Campus de Bage, Bage, RS (Brazil)
2007-02-15
In this work double vector meson production in two-photon interactions at high energies is investigated considering saturation physics. We extend the color dipole picture for this process and study the energy and virtuality dependence of the forward differential cross section. A comparison with previous results is presented, and the contribution of the different photon polarizations is estimated. (orig.)
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
Can parameters of f(0)-mesons be determined correctly analyzing only pi pi scattering?
Czech Academy of Sciences Publication Activity Database
Surovtsev, Yu .S.; Bydžovský, Petr; Kaminski, R.; Lyubovitskij, V. E.; Nagy, M.
2012-01-01
Roč. 86, č. 11 (2012), 116002/1-116002/5 ISSN 1550-7998 R&D Projects: GA ČR(CZ) GAP203/12/2126; GA MŠk LA08002 Institutional support: RVO:61389005 Keywords : mesons * QCD * S- matrix Subject RIV: BE - Theoretical Physics Impact factor: 4.691, year: 2012
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.
Description of meson strong weak and electromagnetic interactions in quantum chiral theory
International Nuclear Information System (INIS)
Volkov, M.K.; Ehbert, D.
1979-01-01
The picture of all the principal meson decays of the basic octet has been obtained in the framework of the SU(3)xSU(3) symmetric chiral model of the field theory. An attempt is made to generalize the nonlinear chiral model for the case of charmed hadrons, i.e., a transition from the SU(3)xSU(3) group to the SU(4)xSU(4) group. The authors have succeeded in elucidating unambiguously the role of the Kabibbo angle both in weak and strong interactions (it defines the structure of weak hadron currents and hadron mass splitting in isotopic multiplets). Proceeding from decays of the basic octet mesons it has been shown that the nonlinear chiral SU(3)xSU(3) symmetric theory may be considered as the quantum field theory, which satisfactorily describes the low-energy meson physics in two first orders of the perturbation theory (tree and single-loop approximations)
Schiraldi, Vito; Morello, Michael Joseph
In fisica delle particelle, con il termine di "oscillazione" si indica la trasformazione di una particella neutra nella sua antiparticella e viceversa, fenomeno dovuto al fatto che gli autostati di flavor non sono autostati della matrice di massa. Il Modello Standard delle interazioni fondamentali predice che l'oscillazione del mesone D^0 avvenga su tempi molto maggiori di una vita media, e appaia perciò come un effetto piccolo, inferiore al percento, in contrasto con il caso dei mesoni B^0 e B^0_s che oscillano con molta maggiore rapidità. Sperimentalmente, l'oscillazione dei mesoni D^0 è rimasta inosservata fino a tempi recenti: la prima evidenza sperimentale dell'esistenza di un effetto di oscillazione è stata ottenuta soltanto nella primavera del 2007 dagli esperimenti BaBar (SLAC, USA) e Belle (KEKB, Japan). Nell'agosto 2007 anche l’esperimento CDF (Fermilab, USA) ha presentato una evidenza simile, basata sull'analisi di una parte del campione di dati disponibile. La tesi descrive gli aspetti speri...
Combined Analysis of Processes ππ → ππ;KK;ηη and J=ψ Decays and Parameters of Scalar Mesons
Czech Academy of Sciences Publication Activity Database
Surovtsev, Yu .S.; Bydžovský, Petr; Kaminski, R.; Lyubovitskij, V. E.; Nagy, M.
2012-01-01
Roč. 8, 056 (2012), s. 1-20 ISSN 1824-8039. [XXI International Baldin Seminar on High energy Physics Problems. Dubna, 10.09.2012-15.09.2012] R&D Projects: GA ČR(CZ) GAP203/12/2126; GA MŠk LA08002 Institutional support: RVO:61389005 Keywords : scalar mesons * meson-meson scattering * multichannel resonances Subject RIV: BE - Theoretical Physics http://pos.sissa.it/archive/conferences/173/056/Baldin%20ISHEPP%20XXI_056.pdf
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
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.)
Triton as a three-nucleon - one-meson problem
International Nuclear Information System (INIS)
Noyes, H.P.; Orlowski, M.K.
1982-06-01
The standard method for basing nuclear physics on elementary particle physics is to first derive a potential and then use this interaction in the nonrelativistic Schroedinger equation for the nucleonic degrees of freedom. Unfortunately there has never been a consensus as to how to perform the first step. Currently we have dispersion-theoretic models and one-boson-exchange models which contain much the same physics, but which differ in detail; more modern approaches start from quark bags, but again there is no consensus as to whether the bag should be large or small. In this paper we offer an alternative approach in which the mesonic and nucleonic degrees of freedom are put on the same footing
Mixing among light scalar mesons and L=1 qq-bar scalar mesons
Energy Technology Data Exchange (ETDEWEB)
Teshima, T. [Department of Applied Physics, Chubu University, Kasugai (Japan)]. E-mail: teshima@isc.chubu.ac.jp; Kitamura, I.; Morisita, N. [Department of Applied Physics, Chubu University, Kasugai (Japan)
2002-06-01
Following the re-establishment of the {sigma}(500) and the {kappa}(900), the light scalar mesons a{sub 0}(980) and f{sub 0}(980) together with the {sigma}(500) and the {kappa}(900) are considered as the chiral scalar partner of pseudoscalar nonet in SU(3) chiral symmetry, and the high mass scalar mesons a{sub 0}(1450), K*{sub 0}(1430), f{sub 0}(1370) and f{sub 0}(1710) turned out to be considered as the L=1 qq-bar scalar mesons. We assume that the high mass of the L=1 qq-bar scalar mesons is caused by the mixing with the light scalar mesons. For the structure of the light scalar mesons, we adopted the qqq-barq-bar model in order to explain the 'scalar meson puzzle'. The inter-mixing between the light scalar nonet and the high mass L=1 qq-bar nonet and the intra-mixing among each nonet are analysed by including the glueball into the high mass scalar nonet. (author)
Mesons beyond the naive quark model
Amsler, C
2004-01-01
We discuss theoretical predictions for the existence of exotic (non-quark-model) mesons and review prominent experimental candidates. These are especially the f0(1500) and f0(1710) mesons for the scalar glueball, fJ(2220) for the tensor glueball, η(1410) for the pseudoscalar glueball, f0(600), f0(980), a0(980), the still to be firmly established κ(800) and the f2(1565) for or two-meson states, and π1(1400), π1(1600) for hybrid states. We conclude that some of these states exist, offer our views and discuss crucial issues that need to be investigated both theoretically and experimentally.
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
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
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.)
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
Meson wave functions in 2-dim QCD
International Nuclear Information System (INIS)
Hildebrandt, S.; Visnjic, V.
1977-07-01
We consider the eigenvalue problem of 't Hooft for the meson spectrum in 2-dim QCD by defining some alternative formulations whose equivalence we prove. Hence we are able to prove that the spectrum is discrete and of finite multiplicity and to derive bounds (upper and lower) for the eigenvalues (ground state, with state and n → infinitely state). We prove that the functions are analytic and use this to carry out explicit numerical calculations of the wave functions for various values of the quark masses and to recalculate the meson spectrum. (orig.) [de
Non-mesonic decay of hypernuclei
International Nuclear Information System (INIS)
Dubach, J.
1986-01-01
The ΛN → NN non-mesonic decay mode of hypernuclei is examined in a model that employs a weak, strangeness-changing meson exchange potential in a Fermi gas model of the hypernucleus. Results are in good agreement with recent experiments for A = 11 and A = 12 hypernuclei. The calculations suggest that the ratio of proton-stimulated to neutron-stimulated decays and the ratio of parity-violating to parity-conserving decays are particularly sensitive to the details of the model. Finally, preliminary results using a more sophisticated shell model of the hypernucleus are discussed. 13 refs., 2 tabs
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)
Isospin-violating mixing in meson nonets
International Nuclear Information System (INIS)
Isgur, N.
1979-01-01
Segregation into ideally mixed nonets results when the OZI-violating interaction which would mix u anti u, d anti d, and s anti s mesons into isospin and SU(3) eigenstates is much weaker than the s anti s-d anti d mass difference. We show that the d anti d-u anti u mass difference can begin to induce a similar segregation into d anti d and anti u mesons which leads to large isospin violations. An experimental example of such large isospin breaking (approx. 30%) which we predict has probably already been seen in f → K anti K. (orig.)
Measurement of D-meson branching ratios
International Nuclear Information System (INIS)
Aguilar-Benitez, M.; Colino, N.; Ladron de Guevara, P.
1986-01-01
Charm data from 360 GeV/c π - p interactions are used to give results on D-meson branching ratios. The analysis is based on 114 charm events containing 183 observed charm particle decays. We present topological branching ratios and decay multiplicities, as well as the following inclusive branching ratios of D-mesons: B(Dsup(+-)->Ksup(-+) + anything) = 0.16+-0.08, B(D 0 ->Ksup(+-) + anything) = 0.44+-0.11, B(Dsup(+-)->esup(+-) + 2,4 charged hadrons) = 0.07+-0.07, B(D 0 ->esup(+-) + anything) = 0.17+-0.07. (orig./HSI)
Turbulent meson condensation in quark deconfinement
Directory of Open Access Journals (Sweden)
Koji Hashimoto
2015-06-01
Full Text Available In a QCD-like strongly coupled gauge theory at large Nc, using the AdS/CFT correspondence, we find that heavy quark deconfinement is accompanied by a coherent condensation of higher meson resonances. This is revealed in non-equilibrium deconfinement transitions triggered by static, as well as quenched electric fields even below the Schwinger limit. There, we observe a “turbulent” energy flow to higher meson modes, which finally results in the quark deconfinement. Our observation is consistent with seeing deconfinement as a condensation of long QCD strings.
A variational study of superconducting correlations within periodic Anderson model
International Nuclear Information System (INIS)
Dua, Piyush; Panwar, Sunil; Singh, Ishwar
2005-01-01
In this work we present the study of heavy fermion (HF) systems represented by the extended periodic Anderson model (PAM). A term, which contains the superconducting correlations, has been included in the conventional PAM. The study has been carried out at finite U. We have used the variational method. The variational wavefunction contains two variational parameters A kσ and B kσ . We have found that both the variational parameters are mutually dependent. We have studied ground state as well as finite temperature properties. We have found that T c increases, as J increases
Remembering Joan (Jan) Mary Anderson (1932-2015).
Chow, Wah Soon; Horton, Peter; Barrett, Martin; Osmond, Charles Barry
2016-08-01
Joan Mary Anderson, known to most people as Jan, was born on May 12, 1932 in Dunedin, New Zealand. She died on August 28, 2015 in Canberra, Australia. To celebrate her life, we present here a brief biography, some comments on her discoveries in photosynthesis during a career spanning more than half a century, and reminiscences from family and friends. We remember this wonderful person who had an unflagging curiosity, creative ability to think laterally, enthusiasm, passion, generosity and love of color and culture.
Price-Anderson Nuclear Safety Enforcement Program. 1996 Annual report
International Nuclear Information System (INIS)
1996-01-01
This first annual report on DOE's Price Anderson Amendments Act enforcement program covers the activities, accomplishments, and planning for calendar year 1996. It also includes the infrastructure development activities of 1995. It encompasses the activities of the headquarters' Office of Enforcement in the Office of Environment, Safety and Health (EH) and Investigation and the coordinators and technical advisors in DOE's Field and Program Offices and other EH Offices. This report includes an overview of the enforcement program; noncompliances, investigations, and enforcement actions; summary of significant enforcement actions; examples where enforcement action was deferred; and changes and improvements to the program
Unbinding slave spins in the Anderson impurity model
Guerci, Daniele; Fabrizio, Michele
2017-11-01
We show that a generic single-orbital Anderson impurity model, lacking, for instance, any kind of particle-hole symmetry, can be exactly mapped without any constraint onto a resonant level model coupled to two Ising variables, which reduce to one if the hybridization is particle-hole symmetric. The mean-field solution of this model is found to be stable to unphysical spontaneous magnetization of the impurity, unlike the saddle-point solution in the standard slave-boson representation. Remarkably, the mean-field estimate of the Wilson ratio approaches the exact value RW=2 in the Kondo regime.
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)
Meson exchange-current effects in heavy nuclei
Energy Technology Data Exchange (ETDEWEB)
Dehesa, J.S.; Lallena, A. (Granada Univ. (Spain). Dept. de Fisica Nuclear); Krewald, S. (Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Kernphysik); Donnelly, T.W. (Massachusetts Inst. of Tech., Cambridge (USA). Lab. for Nuclear Science; Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Physics)
1985-04-15
Meson exchange-current effects in the electroexcitation of magnetic states are evaluated in /sup 16/O and /sup 208/Pb. A new method is suggested which properly includes the influence of the nuclear mean field on meson exchange-current effects. In addition, an effective meson exchange-current operator is developed which considerably simplifies the evaluation of meson exchange-current effects. Over a wide range of momentum transfers, the magnetic cross sections for the electroexcitation of high-spin, stretched 1 plh states are found to be smoothly enhanced by meson exchange currents.
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
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
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.
Quarkonium Contribution to Meson Molecules
Energy Technology Data Exchange (ETDEWEB)
Cincioglu, E.; Yilmazer, A.U. [Ankara University, Department of Physics Engineering, Ankara (Turkey); Nieves, J. [Instituto de Fisica Corpuscular (IFIC) Centro Mixto CSIC-Universidad de Valencia, Institutos de Investigacion de Paterna, Valencia (Spain); Ozpineci, A. [Middle East Technical University, Department of Physics, Ankara (Turkey)
2016-10-15
Starting from a molecular picture for the X(3872) resonance, this state and its J{sup PC} = 2{sup ++} heavy-quark spin symmetry partner [X{sub 2}(4012)] are analyzed within a model which incorporates possible mixings with 2P charmonium (c anti c) states. Since it is reasonable to expect the bare χ{sub c1}(2P) to be located above the D anti D{sup *} threshold, but relatively close to it, the presence of the charmonium state provides an effective attraction that will contribute to binding the X(3872), but it will not appear in the 2{sup ++} sector. Indeed in the latter sector, the χ{sub c2}(2P) should provide an effective small repulsion, because it is placed well below the D{sup *} anti D{sup *} threshold. We show how the 1{sup ++} and 2{sup ++} bare charmonium poles are modified due to the D{sup (*)} anti D{sup (*)} loop effects, and the first one is moved to the complex plane. The meson loops produce, besides some shifts in the masses of the charmonia, a finite width for the 1{sup ++} dressed charmonium state. On the other hand, X(3872) and X{sub 2}(4012) start developing some charmonium content, which is estimated by means of the compositeness Weinberg sum rule. It turns out that in the heavy-quark limit, there is only one coupling between the 2P charmonia and the D{sup (*)} anti D{sup (*)} pairs. We also show that, for reasonable values of this coupling, leading to X(3872) molecular probabilities of around 70-90 %, the X{sub 2} resonance destabilizes and disappears from the spectrum, becoming either a virtual state or one being located deep into the complex plane, with decreasing influence in the D{sup *} anti D{sup *} scattering line. Moreover, we also discuss how around 10-30 % charmonium probability in the X(3872) might explain the ratio of radiative decays of this resonance into ψ(2S)γ and J/ψγ. Finally, we qualitatively discuss within this scheme, the hidden bottom flavor sector, paying a special attention to the implications for the X{sub b} and X
La importancia de Comunidades imaginadas y de Benedict Anderson
Directory of Open Access Journals (Sweden)
Craig Calhoun
2017-01-01
Full Text Available El remarcable libro Comunidades imaginadas de Benedict Anderson reconfiguró el estudio de las naciones y el nacionalismo. Sorprendentemente original, rompió con el excesivo énfasis que hasta el momento se ponía en el continente europeo y con los argumentos falsamente polarizados sobre si las naciones existían desde siempre o eran meros epifenómenos de los estados modernos. Comunidades imaginadas dirige la atención a la dinámica de la imaginación organizada social y culturalmente como proceso que se encuentra en el corazón de la cultura política, la comprensión de uno mismo y la solidaridad, idea que, como innovación de primer orden en la comprensión de los ‘imaginarios sociales’, tuvo una influencia que va más allá del estudio del nacionalismo. Sin embargo, el enfoque de Anderson conservó el incapié en las condiciones materiales que configuran la cultura y en las instituciones que facilitan su reproducción, desde periódicos y novelas a censos, mapas y museos.
Permittivity disorder induced Anderson localization in magnetophotonic crystals
Energy Technology Data Exchange (ETDEWEB)
Abdi-Ghaleh, R., E-mail: r.abdi@bonabu.ac.ir [Department of Laser and Optical Engineering, University of Bonab, 5551761167 Bonab (Iran, Islamic Republic of); Namdar, A. [Faculty of Physics, University of Tabriz, 5166614766 Tabriz (Iran, Islamic Republic of)
2016-11-15
This theoretical study was carried out to investigate the permittivity disorder induced Anderson localization of light in one-dimensional magnetophotonic crystals. It was shown that the disorder create the resonant transmittance modes associated with enhanced Faraday rotations inside the photonic band gap. The average localization length of the right- and left-handed circular polarizations (RCP and LCP), the total transmittance together with the ensemble average of the RCP and LCP phases, and the Faraday rotation of the structure were also investigated. For this purpose, the off-diagonal elements of the permittivity tensor were varied for various wavelengths of incident light. The obtained results revealed the nonreciprocal property of circular eigen modes. This study can potentially open up a new aspect for utilizing the disorder magnetophotonic structures in nonreciprocal systems such as isolators and circulators. - Highlights: • We theoretically investigated the permittivity disorder induced Anderson localization of light in magnetophotonic crystals. • The disorder considered in the diagonal elements of the permittivity tensor of magneto-optical layers. • The disorder create the resonant transmittance modes associated with enhanced Faraday rotations in the photonic band gap. • The average localization length of the circular polarizations and the ensemble average of their phases were investigated. • The obtained results revealed the nonreciprocal property of circular eigen modes.
Price-Anderson Act - the third decade. Report to Congress
International Nuclear Information System (INIS)
Saltzman, J.
1983-12-01
Subsection 170p. of the Atomic Energy Act of 1954, as amended, requires that the Commission submit to the Congress by August 1, 1983, a detailed report on the need for continuation or modification of Section 170 of the Act, the Price-Anderson provisions. The report is divided into four sections with detailed subject reports appended to the main report. Sections I through III include an examination of issues that the Commission was required by statute to study (i.e., condition of the nuclear industry, state of knowledge of nuclear safety, and availability of private insurance), and discussion of other issues of interest and importance to the Congress and to the public. The subjects covered are as follows: (1) overview of the Price-Anderson system; (2) the state of knowledge of nuclear safety; (3) availability of private insurance; (4) conditions of the nuclear industry; (5) causality and proof of damages; (6) limitation of liability and subsidy; and (7) a proposal that would provide for removal of the limitation of liability but with limited annual liability payments. Section IV of the report contains conclusions and recommendations. Section V contains a bibliography
Energy Technology Data Exchange (ETDEWEB)
Blossier, B
2006-06-15
We have studied some phenomenological aspects of the B meson physics by using lattice QCD, which is a non perturbative method (based on the first principles of Quantum Field Theory) of computing Green functions of the theory. Pionic couplings g{sub 1} and g{sub 2}, parameterizing the effective chiral Lagrangian which describes interactions between heavy-light mesons and soft pions, have been computed beyond the quenched approximation (at N{sub f} = 2). We have renormalized the operator q-bar{gamma}{sub {mu}}{gamma}{sup 5}q non perturbatively by using chiral Ward identities. We obtain g{sub 1} = 0.4/0.6 and g{sub 2} = -0.1/-0.3. We have estimated from an un-quenched simulation (at N{sub f} = 2) the strange quark mass: the non perturbative renormalisation scheme RI-MOM has been applied. After the matching in the MS scheme the result is m{sub s}(2 GeV) = 101 {+-} 8(-0,+25) MeV. We have proposed a method to calculate on the lattice the Heavy Quark Effective Theory form factors of the semileptonic transitions B {yields} D{sup **} at zero recoil. The renormalisation constant of the operator h-bar{gamma}{sub i}{gamma}{sup 5}D{sub j}h has been computed at one-loop order of the perturbation theory. We obtain {tau}{sub 1/2}(1) = 0.3/0.5 and {tau}{sub 3/2}(1) 0.5/0.7. Eventually the bag parameter B{sub B{sub s}} associated the B{sub s} - B{sub s}-bar mixing amplitude in the Standard Model has been estimated in the quenched approximation by using for the strange quark an action which verifies the chiral symmetry at finite lattice spacing a. Thus systematic errors are significantly reduced in the renormalisation procedure because the spurious mixing of the four-fermion operator h-bar{gamma}{sub {mu}}{sub L}qh-bar{gamma}{sub {mu}}{sub L}q with four-fermion operators of different chirality is absent. The result is B{sub B{sub s}} = 0.92(3). (author)
Design of a Municipal Yard Waste Composting Facility for Anderson County, South Carolina
National Research Council Canada - National Science Library
Klapmeyer, Michael
2003-01-01
.... Large-scale composting is a proven method by which Anderson County can demonstrate sound environmental stewardship while drastically reducing the volume of waste entering county landfills, thereby...
International Nuclear Information System (INIS)
Duong Van Phi; Duong Anh Duc
1993-08-01
The decay channels of the D s -meson are deduced from a Selection Rule and a Lagrangian, formed on L*O(4) group invariance and on principle of minimal structure. A comparison of the results with experimental data is made. (author). 4 refs
Vector mesons in strongly interacting matter
Indian Academy of Sciences (India)
... used to extract experimental information on in-medium properties of hadrons. Results on the light vector mesons ρ, , and , are summarized and compared. Almost all experiments report a softening of the spectral functions with increases in width depending on the density and temperature of the hadronic environment.
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.
Vector mesons in strongly interacting matter
Indian Academy of Sciences (India)
Properties of hadrons in strongly interacting matter provide a link between quantum chromodynamics in the ... Top: Spectral function of the ρ-meson at normal nuclear matter density as a function of mass and ... directly but folded with the branching ratio ΓV →p1+p2 /Γtot into the specific final channel one is investigating.
Anomalies in radiation decays of charmed mesons
International Nuclear Information System (INIS)
Kalinovskij, Yu.L.; Pervushin, V.N.; Sarikov, N.A.
1986-01-01
The amplitudes of the charmed meson decays D→0 - +0 - +γ and F→0 - +0 - +γ are calculated in the framework of the SU(4)xSU(4)-chiral Lagrangians with account for anomalies. It is shown that in this approach no E1-transition exists
Versatile secondary beam for the meson area
International Nuclear Information System (INIS)
Kirk, T.
1982-03-01
A new secondary beam design is outlined for the Meson M6 Beamline that combines versatility with economy. The beamline described will transport charged particles of either sign to 800 GeV/c and bring the beam to a focus in one of three potential experimental areas. The plan makes maximal use of existing civil construction
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.)
QCD sum rules for light mesons
International Nuclear Information System (INIS)
Narison, S.
1980-10-01
Bounds on the leptonic widths of light mesons rho, ω, phi, A 1 , Ksup(*) are derived from the positivity and the analyticity of the spectral functions, within the framework of quantum chromodynamics (QCD). A comparison of the bounds with previous estimates and with experiment is done. (author)
Meson production in Ф· reactions
Indian Academy of Sciences (India)
Then, by making use of conservation laws the four momentum vectors of the unobserved mesons could be extracted. Recoils being emitted under zero degree in the .... The lions share to the forward back- ward asymmetry comes from l = 1. In figure 7 we show the momentum dependence of the presently deduced values of ...
Vector mesons in strongly interacting matter
Indian Academy of Sciences (India)
Results on the light vector mesons ρ, , and , are summarized and compared. Almost all experiments report a softening of the spectral functions with increases in width depending on the density and temperature of the hadronic environment. No evidence for mass shifts is found in majority of the experiments. Remaining ...
Charmonium meson and hybrid radiative transitions
Energy Technology Data Exchange (ETDEWEB)
Guo, Peng [Indiana U., JLAB; Yépez-Martínez, Tochtli [Indiana U.; Szczepaniak, Adam P. [Indiana U., JLAB
2014-06-01
We consider the non-relativistic limit of the QCD Hamiltonian in the Coulomb gauge, to describe radiative transitions between conventional charmonium states and from the lowest multiplet of cc¯ hybrids to charmonium mesons. The results are compared to potential quark models and lattices calculations.
QCD confinement and the meson spectrum
González, P; Valcarce, A; Vijande, J
2003-01-01
From QCD and lattice calculations two specific forms of quark confining potential, a strict linear and a screened linear confinement, come out. Both forms of the potential, implemented by the one gluon exchange interaction, are applied to the description of heavy quarkonia: cc and bb. Applications to light hadrons, mesons and baryons, are also commented. (11 refs).
meson properties and its leptonic radiative decays
Indian Academy of Sciences (India)
Now there is no one who doubt the color-singlet mechanism for double heavy meson production. Whereas the so-called color-octet mechanism still need to be tested, although it has been proposed for years and obtained a few experimental supports. Besides the reasons mentioned here precisely, the first observation of the ...
Electromagnetic Production of η and η' Mesons
International Nuclear Information System (INIS)
Stroeher, H.
2002-01-01
The production of eta (η) and eta-prime (η') mesons on free and bound nucleons by electromagnetic probes, i.e. real and virtual photons, is an old but very active and viable field of research. A brief summary of the present status and knowledge with a detailed reference list is given
Studies of nucleon resonance structure in exclusive meson electroproduction
International Nuclear Information System (INIS)
Aznauryan, I.G.; Bashir, A.; Braun, V.M.
2013-01-01
Studies of the structure of excited baryons are key factors to the N* program at Jefferson Lab (JLab). Within the first year of data taking with the Hall B CLAS12 detector following the 12 GeV upgrade, a dedicated experiment will aim to extract the N* electrocouplings at high photon virtualities Q 2 . This experiment will allow exploration of the structure of N* resonances at the highest photon virtualities ever achieved, with a kinematic reach up to Q 2 = 12 GeV 2 . This high-Q 2 reach will make it possible to probe the excited nucleon structures at distance scales ranging from where effective degrees of freedom, such as constituent quarks, are dominant through the transition to where nearly massless bare-quark degrees of freedom are relevant. In this document, we present a detailed description of the physics that can be addressed through N* structure studies in exclusive meson electroproduction. The discussion includes recent advances in reaction theory for extracting N* electrocouplings from meson electroproduction off protons, along with Quantum Chromodynamics (QCD)-based approaches to the theoretical interpretation of these fundamental quantities. This program will afford access to the dynamics of the nonperturbative strong interaction responsible for resonance formation, and will be crucial in understanding the nature of confinement and dynamical chiral symmetry breaking in baryons, and how excited nucleons emerge from QCD. (author)
Constraining secret gauge interactions of neutrinos by meson decays
Bakhti, P.; Farzan, Y.
2017-05-01
Secret coupling of neutrinos to a new light vector boson, Z', with a mass smaller than 100 MeV is motivated within a myriad of scenarios which are designed to explain various anomalies in particle physics and cosmology. Due to the longitudinal component of the massive vector boson, the rates of three-body decay of charged mesons (M ) such as the pion and the kaon to the light lepton plus neutrino and Z' (M →l ν Z') are enhanced by a factor of (mM/mZ')2. On the other hand, the standard two body decay M →l ν is suppressed by a factor of (ml/mM)2 due to chirality. We show that in the case of (M →e ν Z'), the enhancement of mM4/me2mZ'2˜1 0 8-1 010 relative to two-body decay (M →e ν ) enables us to probe very small values of gauge coupling for νe. The strongest bound comes from the RK≡Br (K →e +ν )/Br (K →μ +ν ) measurement in the NA62 experiment. The bound can be significantly improved by customized searches for signals of three-body charged meson decay into the positron plus missing energy in the NA62 and/or PIENU data.
Flavor Dependence of Hadroproduced Charm Strange Mesons
Energy Technology Data Exchange (ETDEWEB)
Jedicke, Robert [Toronto U.
1992-01-01
Experiment 769 at the Tagged Photon Laboratory of the Fermi National Accelerator Laboratory wrote approximately 400x$10^6$ events to tape from the reactions of a tagged hadronic beam consisting of $\\pi$, K and p. The interactions took place within a foil target assembly including targets ofW, Be, Cu and Al. We use the D8 meson to determine ifthere exists a dependence of the production properties of the meson on the incident beam particle flavour. A total sample of 83±13 $D_s$ mesons in the $\\phi \\pi$ and $K^* K$ decay modes yields 29±8, 15±5 and 5.6±4.2 $D_s$ mesons using only the transverse energy trigger for the $\\pi$, K and p beams respectively. This is the world's largest sample of kaon induced $D_s$ mesons. This indicates an average $\\sigma$ •B (normalizing B($D_s \\to tK^*K$) to B($D_s \\to \\phi \\pi$)) over the two modes of 0.036±0.015μb/nucleon, 0.044±0.018μb/nucleon and 0.035±0.025μb/nucleon for each of the three different beam particles respectively using $A^{0.95 ± 0.05}$ for $X_F$ > O. These values are consistent with recent measurements by the ACCMOR collaboration at CERN. The absolute cross sections for production of $D_s$ by each of the three beam particles are calculated using the world average of the branching ratio to the $\\phi \\pi$ decay mode. Assuming that all systematic errors cancel, the ratio of the K to $\\pi$ absolute $D_s$ production cross section is found to be 1.2 ± 0.7 for $X_F$ > O. The $X_F$ and $PT^2$ distributions of the Ds mesons for all three beam particles are also presented. All of these results are compared to QCD predictions as well as the LUND Monte Carlo. The differential distributions are consistent to within errors with other experimental results. We find no evidence for a flavour dependence of the production of the $D_s$ meson in the total and differential cross sections.
Many-body Anderson localization of strongly interacting bosons in random lattices
International Nuclear Information System (INIS)
Katzer, Roman
2015-05-01
In the present work, we investigate the problem of many-body localization of strongly interacting bosons in random lattices within the disordered Bose-Hubbard model. This involves treating both the local Mott-Hubbard physics as well as the non-local quantum interference processes, which give rise to the phenomenon of Anderson localization, within the same theory. In order to determine the interaction induced transition to the Mott insulator phase, it is necessary to treat the local particle interaction exactly. Therefore, here we use a mean-field approach that approximates only the kinetic term of the Hamiltonian. This way, the full problem of interacting bosons on a random lattice is reduced to a local problem of a single site coupled to a particle bath, which has to be solved self-consistently. In accordance to previous works, we find that a finite disorder width leads to a reduced size of the Mott insulating regions. The transition from the superfluid phase to the Bose glass phase is driven by the non-local effect of Anderson localization. In order to describe this transition, one needs to work within a theory that is non-local as well. Therefore, here we introduce a new approach to the problem. Based on the results for the local excitation spectrum obtained within the mean-field theory, we reduce the full, interacting model to an effective, non-interacting model by applying a truncation scheme to the Hilbert space. Evaluating the long-ranged current density within this approximation, we identify the transition from the Bose glass to the superfluid phase with the Anderson transition of the effective model. Resolving this transition using the self-consistent theory of localization, we obtain the full phase diagram of the disordered Bose-Hubbard model in the regime of strong interaction and larger disorder. In accordance to the theorem of inclusions, we find that the Mott insulator and the superfluid phase are always separated by the compressible, but insulating
Central Production of Two-Pseudoscalar Meson Systems at the COMPASS Experiment at CERN
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...
Observation of the weak time’s arrow in B mesons
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.
In-medium pseudoscalar D/B mesons and charmonium decay width
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.
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.)
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 parabolic Anderson model random walk in random potential
König, Wolfgang
2016-01-01
This is a comprehensive survey on the research on the parabolic Anderson model – the heat equation with random potential or the random walk in random potential – of the years 1990 – 2015. The investigation of this model requires a combination of tools from probability (large deviations, extreme-value theory, e.g.) and analysis (spectral theory for the Laplace operator with potential, variational analysis, e.g.). We explain the background, the applications, the questions and the connections with other models and formulate the most relevant results on the long-time behavior of the solution, like quenched and annealed asymptotics for the total mass, intermittency, confinement and concentration properties and mass flow. Furthermore, we explain the most successful proof methods and give a list of open research problems. Proofs are not detailed, but concisely outlined and commented; the formulations of some theorems are slightly simplified for better comprehension.
Compressible ferrimagnetism in the depleted periodic Anderson model
Costa, N. C.; Araújo, M. V.; Lima, J. P.; Paiva, T.; dos Santos, R. R.; Scalettar, R. T.
2018-02-01
Tight-binding Hamiltonians with single and multiple orbitals exhibit an intriguing array of magnetic phase transitions. In most cases the spin ordered phases are insulating, while the disordered phases may be either metallic or insulating. In this paper we report a determinant quantum Monte Carlo study of interacting electrons in a geometry which can be regarded as a two-dimensional periodic Anderson model with depleted interacting (f ) orbitals. For a single depletion, we observe an enhancement of antiferromagnetic correlations and formation of localized states. For half of the f orbitals regularly depleted, the system exhibits a ferrimagnetic ground state. We obtain a quantitative determination of the nature of magnetic order, which we discuss in the context of Tsunetsugu's theorem, and show that, although the dc conductivity indicates insulating behavior at half filling, the compressibility remains finite.
Spin-liquid state in an inhomogeneous periodic Anderson model
Caro, R. C.; Franco, R.; Silva-Valencia, J.
2018-02-01
We studied the ground state of alkaline-earth-metal atoms confined in one-dimensional optical lattices with an effective hybridization generated by a suitable laser field. This system is modeled by the periodic Anderson model plus a quadratic confining potential, and we adopted the density-matrix renormalization group to calculate its ground state. We found a one-to-one correspondence between the local variance, the local von Neumann entropy, and the on-site spin-spin correlation. For low global densities, we observed the formation of local singlets between delocalized and localized atoms and found Kondo spin-liquid domains that can be tuned with the confining potential, the hybridization, and the local repulsion. Band insulator, metallic, phase separation, and Kondo spin-liquid regions coexist in the ground state.
Price-Anderson Nuclear Safety Enforcement Program. 1997 annual report
International Nuclear Information System (INIS)
1998-01-01
This report summarizes activities in the Department of Energy's Price-Anderson Amendments Act (PAAA) Enforcement Program in calendar year 1997 and highlights improvements planned for 1998. The DOE Enforcement Program involves the Office of Enforcement and Investigation in the DOE Headquarters Office of Environment, Safety and Health, as well as numerous PAAA Coordinators and technical advisors in DOE Field and Program Offices. The DOE Enforcement Program issued 13 Notices of Violation (NOV's) in 1997 for cases involving significant or potentially significant nuclear safety violations. Six of these included civil penalties totaling $440,000. Highlights of these actions include: (1) Brookhaven National Laboratory Radiological Control Violations / Associated Universities, Inc.; (2) Bioassay Program Violations at Mound / EG ampersand G, Inc.; (3) Savannah River Crane Operator Uptake / Westinghouse Savannah River Company; (4) Waste Calciner Worker Uptake / Lockheed-Martin Idaho Technologies Company; and (5) Reactor Scram and Records Destruction at Sandia / Sandia Corporation (Lockheed-Martin). Sandia / Sandia Corporation (Lockheed-Martin)
Classical diffusion, Anderson localization, and spectral statistics in billiard chains
International Nuclear Information System (INIS)
Dittrich, T.; Doron, E.; Smilansky, U.
1993-03-01
We study spectral properties of quasi one-dimensional extended systems that show deterministic diffusion on the classical level and Anderson localization in the quantal description. Using semiclassical arguments, we relate to universal aspects of the spectral fluctuations to features of the set of classical periodic orbits, expressed in terms of probability to perform periodic motion, that are likewise universal. This allows to derive an analytical expression for the spectral form factor which reflects the diffusive nature of the corresponding classical dynamics. It defines a novel spectral universality class which covers the transition between GOE statistics in the limit of a small ratio of the system size to the localization length, corresponding to the metallic regime of disordered systems, to Poissonian level fluctuations in the opposite limit. Our semiclassical predictions are illustrated and confirmed by a numerical investigation of aperiodic chains of chaotic billiards. (authors)
Unconstitutionality of Section 170 (e) of the price Anderson Act
International Nuclear Information System (INIS)
1977-01-01
Several environmental protection groups in the State of North Carolina have recently contested the conformity with the United States Constitution of Section 170 (e) of the Atomic Energy Act (Price-Anderson Act). The court seized of the question (the United States District Court for the western district of North Carolina, Charlotte Division) held in March 1977 that this Section and the other provisions of the Atomic Energy Act concerning implementation of the $560 million limitation of liability for nuclear damage were unconstitutional and unenforceable insofar as they applied to nuclear incidents occurring inside the United States. The defendants, the former United States Atomic Energy Commission and its then Commissioners as well as the Duke Power Company (the local electricity company) will appeal this decision. The note on case law analyses the arguments retained by the court. (NEA) [fr
Superconductivity in the periodic Anderson model with anisotropic hybridization
International Nuclear Information System (INIS)
Sarasua, L.G.; Continentino, Mucio A.
2003-01-01
In this work we study superconductivity in the periodic Anderson model with both on-site and intersite hybridization, including the interband Coulomb repulsion. We show that the presence of the intersite hybridization together with the on-site hybridization significantly affects the superconducting properties of the system. The symmetry of the hybridization has a strong influence in the symmetry of the superconducting order parameter of the ground state. The interband Coulomb repulsion may increase or decrease the superconducting critical temperature at small values of this interaction, while is detrimental to superconductivity for strong values. We show that the present model can give rise to positive or negative values of dT c /dP, depending on the values of the system parameters
X-slave boson approach to the periodic Anderson model
International Nuclear Information System (INIS)
Franco, R.; Figueira, M.S.; Foglio, M.E.
2001-01-01
The periodic anderson model (PAM) in the limit U=∞, can be studied by employing the Hubbard X operators to project out the unwanted states. In a previous work, we have studied the cumulant expansion of this Hamiltonian employing the hybridization as a perturbation, but probability conservation of the local states (completeness) is not usually satisfied when partial expansions like the 'chain approximation (CHA)' are employed. To consider this problem, we use a technique similar to the one employed by Coleman to treat the same problem with slave-bosons in the mean-field approximation. Assuming a particular renormalization for hybridization, we obtain a description that avoids an unwanted phase transition that appears in the mean-field slave-boson method at intermediate temperatures
All-solid-state cavity QED using Anderson-localized modes in disordered photonic crystal waveguides
DEFF Research Database (Denmark)
Lodahl, Peter; Sapienza, Luca; Nielsen, Henri Thyrrestrup
2010-01-01
We employ Anderson-localized modes in deliberately disordered photonic crystal waveguides to confine light and enhance the interaction with matter. A 15-fold enhancement of the decay rate of a single quantum dot is observed meaning that 94% of the emitted single photons are coupled to an Anderson...
Mott Transition of Cerium Compound CeCu2Si2 in the Anderson ...
African Journals Online (AJOL)
The Exact-Diagonalization (ED) technique is applied to the Single Site Impurity Anderson Model (SIAM) and the Periodic Anderson Model (PAM) to elucidate the nature of the ground-state energy and the phase diagram of the two models. The results obtained show a smooth phase transition from an antiferromagnetic ...
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
The topological Anderson insulator phase in the Kane-Mele model
Orth, Christoph P.; Sekera, Tibor; Bruder, Christoph; Schmidt, Thomas L.
2016-04-01
It has been proposed that adding disorder to a topologically trivial mercury telluride/cadmium telluride (HgTe/CdTe) quantum well can induce a transition to a topologically nontrivial state. The resulting state was termed topological Anderson insulator and was found in computer simulations of the Bernevig-Hughes-Zhang model. Here, we show that the topological Anderson insulator is a more universal phenomenon and also appears in the Kane-Mele model of topological insulators on a honeycomb lattice. We numerically investigate the interplay of the relevant parameters, and establish the parameter range in which the topological Anderson insulator exists. A staggered sublattice potential turns out to be a necessary condition for the transition to the topological Anderson insulator. For weak enough disorder, a calculation based on the lowest-order Born approximation reproduces quantitatively the numerical data. Our results thus considerably increase the number of candidate materials for the topological Anderson insulator phase.
Shiba states and zero-bias anomalies in the hybrid normal-superconductor Anderson model
Žitko, Rok; Lim, Jong Soo; López, Rosa; Aguado, Ramón
2015-01-01
Hybrid semiconductor-superconductor systems are interesting melting pots where various fundamental effects in condensed-matter physics coexist. For example, when a quantum dot is coupled to a superconducting electrode two very distinct phenomena, superconductivity and the Kondo effect, compete. As a result of this competition, the system undergoes a quantum phase transition when the superconducting gap Δ is of the order of the Kondo temperature TK. The underlying physics behind such transition ultimately relies on the physics of the Anderson model where the standard metallic host is replaced by a superconducting one, namely the physics of a (quantum) magnetic impurity in a superconductor. A characteristic feature of this hybrid system is the emergence of subgap bound states, the so-called Yu-Shiba-Rusinov (YSR) states, which cross zero energy across the quantum phase transition, signaling a switching of the fermion parity and spin (doublet or singlet) of the ground state. Interestingly, similar hybrid devices based on semiconducting nanowires with spin-orbit coupling may host exotic zero-energy bound states with Majorana character. Both parity crossings and Majorana bound states (MBSs) are experimentally marked by zero-bias anomalies in transport, which are detected by coupling the hybrid device with an extra normal contact. We here demonstrate theoretically that this extra contact, usually considered as a nonperturbing tunneling weak probe, leads to nontrivial effects. This conclusion is supported by numerical renormalization-group calculations of the phase diagram of an Anderson impurity coupled to both superconducting and normal-state leads. We obtain this phase diagram for an arbitrary ratio Δ/TK, which allows us to analyze relevant experimental scenarios, such as parity crossings as well as Kondo features induced by the normal lead, as this ratio changes. Spectral functions at finite temperatures and magnetic fields, which can be directly linked to
International Nuclear Information System (INIS)
Yamamoto, H.
1994-01-01
The author discusses a number of different topics. First is the question of where CESR will be in the year 2000, in terms of luminosity and its detector, and the impact of this on charm physics. Also what has been learned of semileptonic decays of D 0 , D + , D s , and Cabbibo-favored/suppressed decays. Studies of hadronic decays, Cabbibo-favored/suppressed, rare decays, mixing, and CP invariance. What role can a Tau Charm Factory play in this type of physics, and what can it tell us beyond what we can reach at present
Two-particle Bound States: Mesons and Glueballs
Directory of Open Access Journals (Sweden)
Ganbold G.
2010-04-01
Full Text Available A relativistic quantum-ﬁeld model based on analytic conﬁnement is considered to study the twoquark and two-gluon bound states. For the spectra of two-particle bound states we solve the ladder Bethe-Salpeter equation. We provide a new, independent and analytic estimate of the lowest glueball mass and found it at 1660 MeV. The conventional mesons and the weak decay constants are described to extend the consideration. By using a few parameters (the quark masses, the coupling constant and the conﬁnement scale we obtain numerical results which are in reasonable agreement with experimental evidence in the wide range of energy scale from 140MeV up to 9 GeV. The model can serve a reasonable framework to describe simultaneously diﬀerent sectors in low-energy particle physics.
Meson exchange and neutral weak currents
Energy Technology Data Exchange (ETDEWEB)
Beck, D.H. [Univ. of Illinois, Urbana, IL (United States)
1994-04-01
Measurements of parity-violating electron scattering asymmetries to determine weak neutral currents in nuclei will be effected by the presence of meson exchange currents. Present low momentum transfer calculations, based on a flavor independent framework, show these effects to be small. In general, however, as the momentum transfer increases to values typical of deep-inelastic scattering, fragmentation functions show a clear flavor dependence. It is suggested that a good experimental starting point for understanding the flavor dependence of meson production and exchange currents is the Q{sup 2} dependence of parity-violating asymmetry in inclusive single pion electroproduction. A CEBAF facility with doubled energy is necessary to approach momentum transfers where this process begins to scale.
A Dependence of Charmed Meson Production
Energy Technology Data Exchange (ETDEWEB)
Alves, Gilvan Augusto [Rio de Janeiro, CBPF
1992-03-01
One report is presented of a recent direct measurement of the nucleon number (A) dependence of the production cross sections for the charmed mesons $D^0$ and $D^+$ using $\\pi^+_{-}$ and $K^+_{-}$ beams incident on a segmented target of Be, Al, Cu and W. The data derive from the experiment E769 - Hadroproductlon of Charm at Fermilab. The experimental apparatus is described together with the following analysis. Starting from a sample of -1500 D mesons in the range of $O< x_{f} <1$, the data are found to be well described by the parameterization $\\sigma_{A}$ = $\\sigma_{O}$ , with $\\alpha = 0.99 \\pm 0.03$. The $x_f$ dependence of $\\alpha$ is examined and the results obtained are compared with those of other .experiments and wl th -theoretical expectations based on perturbatlve QCD and on an EMC like model of nuclear shadowing
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.)
LHCb: LHCb results on $B$ meson mixing
Eitschberger, U
2013-01-01
On the poster three LHCb results on B meson mixing using a datasample of 1 fb$^{-1}$ of $pp$ collisions at $\\sqrt{s} =$ 7 TeV are presented. The B meson oscillation frequencies are measured as $\\Delta m_d = 0.5156 \\pm 0.0051 (\\text{stat}) \\pm 0.0033 (\\text{syst}) \\text{ps}^{-1}$ and $\\Delta m_s = 17.768 \\pm 0.023 (\\text{stat}) \\pm 0.006 (\\text{syst}) \\text{ps}^{-1}$. The CP violation observables in the decay channel $B^0 \\rightarrow J/\\psi K^0_S$ are determined as $S_{J/\\psi K^0_S} = 0.73 \\pm 0.07 (\\text{stat})\\pm 0.04 (\\text{syst})$ and $C_{J/\\psi K^0_S} = 0.03 \\pm 0.09 (\\text{stat})\\pm 0.01 (\\text{syst})$.
The lightest hybrid meson supermultiplet in QCD
Energy Technology Data Exchange (ETDEWEB)
Dudek, Jozef J
2011-10-01
We interpret the spectrum of meson states recently obtained in non-perturbative lattice QCD calculations in terms of constituent quark-antiquark bound states and states, called 'hybrids', in which the q{bar q} pair is supplemented by an excitation of the gluonic field. We identify a lightest supermultiplet of hybrid mesons with J{sup PC} = (0,1,2){sup {-+}}, 1{sup -} built from a gluonic excitation of chromomagnetic character coupled to q{bar q} in an S-wave. The next lightest hybrids are suggested to be quark orbital excitations with the same gluonic excitation, while the next distinct gluonic excitation is significantly heavier. Existing models of gluonic excitations are compared to these findings and possible phenomenological consequences explored.
Production of polarized vector mesons off nuclei
International Nuclear Information System (INIS)
Kopeliovich, B. Z.; Nemchik, J.; Schmidt, Ivan
2007-01-01
Using the light-cone QCD dipole formalism we investigate manifestations of color transparency (CT) and coherence length (CL) effects in electroproduction of longitudinally (L) and transversally (T) polarized vector mesons. Motivated by forthcoming data from the HERMES experiment we predict both the A and Q 2 dependence of the L/T ratios for ρ 0 mesons produced coherently and incoherently off nuclei. For an incoherent reaction the CT and CL effects add up and result in a monotonic A dependence of the L/T ratio at different values of Q 2 . In contrast, for a coherent process the contraction of the CL with Q 2 causes an effect opposite to that of CT and we expect quite a nontrivial A dependence
Energy Technology Data Exchange (ETDEWEB)
Erdmenger, J. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Muenchen (Germany); Evans, N. [Southampton University, School of Physics and Astronomy, Southampton (United Kingdom); Isaac Newton Institute for Mathematical Sciences, Cambridge (United Kingdom); Kirsch, I. [ETH Zuerich, Institut fuer Theoretische Physik, Zuerich (Switzerland); Threlfall, E.J. [Southampton University, School of Physics and Astronomy, Southampton (United Kingdom)
2008-01-15
We review recent progress in studying mesons within gauge/gravity duality, in the context of adding flavour degrees of freedom to generalizations of the AdS/CFT correspondence. Our main focus is on the 'top-down approach' of considering models constructed within string theory. We explain the string-theoretical constructions in detail, aiming at non-specialists. These give rise to a new way of describing strongly coupled confining large-N gauge theories similar to large-N QCD. In particular, we consider gravity dual descriptions of spontaneous chiral symmetry breaking, and compare with lattice results. A further topic covered is the behaviour of flavour bound states in finite-temperature field theories dual to a gravity background involving a black hole. We also describe the 'bottom up' phenomenological approach to mesons within AdS/QCD. Some previously unpublished results are also included. (orig.)
Meson Spectroscopy from QCD - Project Results
Energy Technology Data Exchange (ETDEWEB)
Dudek, Jozef [Old Dominion Univ., Norfolk, VA (United States)
2017-04-17
Highlights of the research include: the determination of the form of the lowest energy gluonic excitation within QCD and the spectrum of hybrid hadrons which follows; the first calculation of the spectrum of hybrid baryons within a first-principles approach to QCD; a detailed mapping out of the phase-shift of elastic ππ scattering featuring the ρ resonance at two values of the light quark mass within lattice QCD; the first (and to date, only) determinations of coupled-channel meson-meson scattering within first-principles QCD; the first (and to date, only) determinations of the radiative coupling of a resonant state, the ρ appearing in πγ→ππ; the first (and to date, only) determination of the properties of the broad σ resonance in elastic ππ scattering within QCD without unjustified approximations.
Production and propagation of neutral mesons at relativistic energies
International Nuclear Information System (INIS)
Loehner, H.
1997-01-01
The formation and evolution of compressed nuclear matter is studied in heavy ion collisions at relativistic energies. Neutral mesons (π 0 ,η) yields from baryon resonance decays have beam measured for a number of colliding systems and bombarding energies. The energy dependent of the meson yields suggests the formation of an equilibrated baryon system with an initial thermal energy of roughly 85% of the available energy. Collisions of resonances of mesons with nucleons cause absorption redistribution of mesons in phase space. This results in an azimuthal asymmetry of pions. The energy spectra of π 0 and η mesons reveal a scaling with the transverse mass similar to observations at ultrarelativistic energies. This underlines the importance of individual resonances for the spectral distribution of mesons. The azimuthal dependence of baryon energy spectra reveals the influence of shadowing by spectator matter. (authors)
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.
Meson Spectroscopy at CLAS and CLAS12: the present and the future
Energy Technology Data Exchange (ETDEWEB)
Rafaella De Vita
2011-05-01
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 a 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.
Production ratio of pseudoscalar to vector mesons
International Nuclear Information System (INIS)
Chliapnikov, P.V.; Uvarov, V.A.
1990-01-01
The P/V ratio of directly produced pseudoscalar (P) to vector (V) mesons is analysed using the data on the K S 0 and K * (892) total inclusive cross sections in pp, π + p and K ± p reactions. The indication for a change of P/V from a value of about 1 at low energies, where the fragmentation processes dominate, to a value of 1/3, suggested by spin-statistics, at high energies is discussed. (orig.)
Updating experimental results on light meson spectroscopy
International Nuclear Information System (INIS)
Diekmann, B.
1991-06-01
A recollection and summary is given on the understanding of light qanti q (q = u,d,s) mesons under the regime of the qanti q potential turning from a coulombic behaviour to a 'confining' one. In the second part the experimental knowledge obtained in the last years is updated: e + e - experiments, fixed target experiments with hadrons (kaons) and photons and panti p annihilations at LEAR discovered unknown objects and added new constraints on known but not fully understood states. (orig.)
Non-conventional mesons at PANDA
Giacosa, Francesco
2015-04-01
Non-conventional mesons, such as glueballs and tetraquarks, will be in the focus of the PANDA experiment at the FAIR facility. In this lecture we recall the basic properties of QCD and describe some features of unconventional states. We focus on the search of the not-yet discovered glueballs and the use of the extended Linear Sigma Model for this purpose, and on the already discovered but not-yet understood X, Y, Z states.
B decays to excited charm mesons
Energy Technology Data Exchange (ETDEWEB)
Colangelo, P.; De Fazio, F.; Paver, N
1999-04-01
We review several aspects of the phenomenology of P-wave q-barQ mesons: mass splittings, effective strong couplings and leptonic constants. We also describe a QCD sum rule determination to order {alpha}{sub s} of the form factor {tau}{sub 1/}2(y) governing the semileptonic B decays to the charm doublet with J{sup P} = (0{sup +}{sub 1/2}), 1{sup +}{sub 1/2}))00.
Energy Technology Data Exchange (ETDEWEB)
Chan Hongmo [Rutherford Appleton Lab., Chilton (United Kingdom); Tsou Sheungtsun [Oxford Univ. (United Kingdom). Mathematical Inst.
1991-12-01
In expectation of imminent results from the new hyperon beam experiment at CERN concerning the exotic U-meson at 3.1 GeV, we propose a detailed program of experimental tests to check the suggestion that U is a qqq-barq-bar ``M-diquonium`` state. Apart from some very characteristic decay modes, the U is expected to occur together with several analogous states with various quantum numbers to which it is intimately related. (author).
LAMPF: the meson factory. A LASL monograph
International Nuclear Information System (INIS)
Allred, J.C.
1977-08-01
A general and simplified introduction to the entire concept of LAMPF is given in terms of its experimental capabilities. Parts of the current experimental program are used as illustrative examples. Topics discussed include: (1) the evolution of the meson factory; (2) accelerator construction; (3) strong focusing; (4) accelerator innovations at LAMPF; (5) photons and pions; (6) muons as nuclear probes; (7) nuclear chemistry; (8) radiobiology and medical applications; (9) radioisotope production; (10) materials testing; and (11) LAMPF management and users group
Vector meson production from a polarized nucleon
International Nuclear Information System (INIS)
Diehl, M.
2007-04-01
We provide a framework to analyze the electroproduction process ep→epρ with a polarized target, writing the angular distribution of the ρ decay products in terms of spin density matrix elements that parameterize the hadronic subprocess γ * p → ρp. Using the helicity basis for both photon and meson, we find a representation in which the expressions for a polarized and unpolarized target are related by simple substitution rules. (orig.)
Euclidean fields: vector mesons and photons
International Nuclear Information System (INIS)
Loffelholz, J.
1979-01-01
Free transverse vector fields of mass >= 0 are studied. The model is related to the usual free vector meson and electromagnetic quantum field theories by extension of the field operators from transverse to arbitrary test functions. The one-particle states in transverse gauge and their localization are described. Reflexion positivity is proved and derived are free Feynman-Kac-Nelson formulas. An Euclidean approach to a photon field in a spherical world using dilatation covariance and inversions is given
LAMPF: the meson factory. A LASL monograph
Energy Technology Data Exchange (ETDEWEB)
Allred, J.C.
1977-08-01
A general and simplified introduction to the entire concept of LAMPF is given in terms of its experimental capabilities. Parts of the current experimental program are used as illustrative examples. Topics discussed include: (1) the evolution of the meson factory; (2) accelerator construction; (3) strong focusing; (4) accelerator innovations at LAMPF; (5) photons and pions; (6) muons as nuclear probes; (7) nuclear chemistry; (8) radiobiology and medical applications; (9) radioisotope production; (10) materials testing; and (11) LAMPF management and users group. (PMA)
Holographic picture of heavy vector meson melting
Energy Technology Data Exchange (ETDEWEB)
Braga, Nelson R.F.; Diles, Saulo [Universidade Federal do Rio de Janeiro, Instituto de Fisica, Rio de Janeiro, RJ (Brazil); Martin Contreras, Miguel Angel [Universidad de los Andes, High Energy Group, Department of Physics, Bogota (Colombia)
2016-11-15
The fraction of heavy vector mesons produced in a heavy ion collision, as compared to a proton-proton collision, serves as an important indication of the formation of a thermal medium, the quark-gluon plasma. This sort of analysis strongly depends on understanding the thermal effects of a medium like the plasma on the states of heavy mesons. In particular, it is crucial to know the temperature ranges where they undergo a thermal dissociation, or melting. AdS/QCD models are know to provide an important tool for the calculation of hadronic masses, but in general are not consistent with the observation that decay constants of heavy vector mesons decrease with excitation level. It has recently been shown that this problem can be overcome using a soft wall background and introducing an extra energy parameter, through the calculation of correlation functions at a finite position of anti-de Sitter space. This approach leads to the evaluation of masses and decay constants of S wave quarkonium states with just one flavor dependent and one flavor independent parameter. Here we extend this more realistic model to finite temperatures and analyze the thermal behavior of the states 1S, 2S and 3S of bottomonium and charmonium. The corresponding spectral function exhibits a consistent picture for the melting of the states where, for each flavor, the higher excitations melt at lower temperatures. We estimate for these six states the energy ranges in which the heavy vector mesons undergo a transition from a well-defined peak in the spectral function to complete melting in the thermal medium. A very clear distinction between the heavy flavors emerges, with the bottomonium state Υ(1S) surviving a deconfinement transition at temperatures much larger than the critical deconfinement temperature of the medium. (orig.)
Exclusive ω meson production at COMPASS
Directory of Open Access Journals (Sweden)
Nowak Wolf-Dieter
2016-01-01
Full Text Available Exclusive ω meson production is studied by the COMPASS Collaboration using the CERN 160 GeV/c muon beam and a transversely polarised proton target. Single-spin and double-spin asymmetries are measured, some of which are sensitive to the Generalised Parton Distributions E that are related to quark orbital angular momenta. The results, which are sensitive also to the pion-pole contribution to the production mechanism, are compared to the predictions of a phenomenological model.
Understanding the baryon and meson spectra
Energy Technology Data Exchange (ETDEWEB)
Pennington, Michael R. [JLAB
2013-10-01
A brief overview is given of what we know of the baryon and meson spectra, with a focus on what are the key internal degrees of freedom and how these relate to strong coupling QCD. The challenges, experimental, theoretical and phenomenological, for the future are outlined, with particular reference to a program at Jefferson Lab to extract hadronic states in which glue unambiguously contributes to their quantum numbers.
Spin O decay angular distribution for interfering mesons in electroproduction
International Nuclear Information System (INIS)
Funsten, H.; Gilfoyle, G.
1994-01-01
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(θ,ψ). 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(θ,ψ) 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 absorbedclose quotes into daughter helicities. The decaying meson's helicity maximally appears in W(θ,ψ). W(θ,ψ) 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(θ,ψ) 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 (θ,ψ), 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
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
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.
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)
D mesons in asymmetric nuclear matter
International Nuclear Information System (INIS)
Mishra, Amruta; Mazumdar, Arindam
2009-01-01
We calculate the in-medium D and D meson masses in isospin-asymmetric nuclear matter in an effective chiral model. The D and D mass modifications arising from their interactions with the nucleons and the scalar mesons in the effective hadronic model are seen to be appreciable at high densities and have a strong isospin dependence. These mass modifications can open the channels of the decay of the charmonium states (Ψ ' ,χ c ,J/Ψ) to DD pairs in dense hadronic matter. The isospin asymmetry in the doublet D=(D 0 ,D + ) is seen to be particularly appreciable at high densities and should show in observables such as their production and flow in asymmetric heavy-ion collisions in the compressed baryonic matter experiments in the future facility of FAIR, GSI. The results of the present work are compared to calculations of the D(D) in-medium masses in the literature using the QCD sum rule approach, quark meson coupling model, and coupled channel approach as well as to those from studies of quarkonium dissociation using heavy-quark potentials from lattice QCD at finite temperatures
Antiproton-proton annihilation into light neutral meson pairs within an effective meson theory
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.
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.)
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
Photoproduction of Light and Exotic Mesons in Hall D
Meyer, Curtis
2000-10-01
The Jefferson Lab Hall D collaboration is proposing a program to search for and study gluonic excitations of mesons using 8-9 GeV linearly polarized photon beams. By extending the nearly non-existent meson data in photoproduction, as well as taking advantage of a spin 1 probe, we expect to be able to produce and study hybrid mesons with exotic, or non q-barq quantum numbers. The properties of these mesons yield information on the dynamic nature of gluons, and yield information on the issue of confinement.
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.
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.)
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/c^{2}. 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.
Medium energy elementary particle physics
Energy Technology Data Exchange (ETDEWEB)
1991-01-01
This report discusses the following topics: muon beam development at LAMPF; muon physics; a new precision measurement of the muon g-2 value; measurement of the spin-dependent structure functions of the neutron and proton; and meson factories. (LSP)
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.)
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
Quark diagram analysis of bottom meson decays emitting pseudoscalar and vector mesons
Kaur, Maninder; Singh, Supreet Pal; Verma, R. C.
2018-01-01
This paper presents the two body weak nonleptonic decays of B mesons emitting pseudoscalar ( P) and vector ( V) mesons within the framework of the diagrammatic approache at flavor SU(3) symmetry level. Using the decay amplitudes, we are able to relate the branching fractions of B → PV decays induced by both b → c and b → u transitions, which are found to be well consistent with the measured data. We also make predictions for some decays, which can be tested in future experiments.
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.)
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.
Kofler, Stefan; Pasquini, Barbara
2017-05-01
The unpolarized, helicity and transversity parton distribution functions of the nucleon are studied within a convolution model where the bare nucleon is dressed by its virtual meson cloud. Using light-front time-ordered perturbation theory, the Fock states of the physical nucleon are expanded in a series involving a bare nucleon and two-particle (meson-baryon) states. The bare baryons and mesons are described with light-front wave functions (LFWFs) for the corresponding valence-parton components. Using a representation in terms of overlap of LFWFs, the role of the nonperturbative antiquark degrees of freedom and the valence-quark contribution at the input scale of the model is discussed for the leading-twist collinear parton distributions. After introducing perturbative QCD effects through evolution to experimental scales, the results are compared with available data and phenomenological extractions. Predictions for the nucleon tensor charge are also presented, finding a very good agreement with recent phenomenological extractions.
Renormalization group analysis of B →π form factors with B -meson light-cone sum rules
Shen, Yue-Long; Wei, Yan-Bing; Lü, Cai-Dian
2018-03-01
Within the framework of the B -meson light-cone sum rules, we review the calculation of radiative corrections to the three B →π transition form factors at leading power in Λ /mb. To resum large logarithmic terms, we perform the complete renormalization group evolution of the correlation function. We employ the integral transformation which diagonalizes evolution equations of the jet function and the B -meson light-cone distribution amplitude to solve these evolution equations and obtain renormalization group improved sum rules for the B →π form factors. Results of the form factors are extrapolated to the whole physical q2 region and are compared with that of other approaches. The effect of B -meson three-particle light-cone distribution amplitudes, which will contribute to the form factors at next-to-leading power in Λ /mb at tree level, is not considered in this paper.
Radiative Decays of the B Meson
Energy Technology Data Exchange (ETDEWEB)
Tanaka, Hirohisa A
2003-09-23
The radiative decays of the B meson to the final states K *(892){gamma} and {rho}(770){gamma} proceed through virtual effective flavor-changing neutral current processes which are sensitive to contributions from high mass scales from within the Standard Model of particle interactions and from possible new physics. In the context of the Standard Model, these transitions are of interest in probing the weak interaction behavior of the top quark. In particular, the ratio of branching fractions for the two processes can be used to extract the ratio of Cabibbo-Kobayashi-Maskawa matrix elements |V{sub td}/V{sub ts}|. Potential new physics contributions in these virtual transitions may induce new sources of direct CP violation and enhancement or suppression of the rate of these processes. The B {yields} K*{gamma} is a manifestation of the b {yields} s{gamma} radiative transition. This process has been previously observed by the CLEO collaboration and its branching fraction measured. While the theoretical prediction for the inclusive rate of b {yields} s{gamma} transitions is more robust than that of the exclusive B {yields} K*{gamma}, the prospects for precise measurements of {Beta}[B {yields} K*{gamma}] and direct CP violation in this channel has attracted considerable attention. The analysis described here represents an improved measurement of the B {yields} K*{gamma} branching factions and a more sensitive search for direct CP violation. In 22.7 x 10{sup 6} B{bar B} events collected by the BABAR detector in 1999-2000, we measure: {Beta}[B{sup 0} {yields} K*{sup 0}{gamma}] = 4.23 {+-} 0.40(stat.) {+-} 0.22(syst.) x 10{sup -5} and {Beta}[B{sup +} {yields} K*{sup +}{gamma}] = 3.83 {+-} 0.62(stat.) {+-} 0.22(syst.) x 10{sup -5}. We find no evidence for direct CP violation in the decays and constrain -0.170 < A{sub CP} < 0.082 at 90% Confidence Level. The B {yields} {rho}{gamma} proceeds through the analogous b {yields} d{gamma} radiative transition. As such, its rate is
Indian Academy of Sciences (India)
We review the effects of new physics on CP asymmetries and decays of mesons. Possible sources and corresponding signals for new physics are studied brieﬂy. We discuss how the decay mode → sℓℓ$ (and → * ℓℓ) will enable us to understand the nature of new physics. We also examine the possibility of truly ...
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.)
Anderson transition in one-dimension using Wegner's Flow equations
Bhattacharjee, Paraj; Quito, Victor; Pekker, David; Refael, Gil
2015-03-01
We study the Anderson transition in one-dimensional random single-particle Hamiltonians with long-range hoppings decaying in a power-law. Explicitly, we consider the single particle tight-binding model in the spin representation with disorder both in the fields and hoppings. It has been shown by Mirlin et. al. that this model shows an extended-to-localized transition as a function of the power-law exponent with a critical multi-fractal regime when the decay exponent is equal to one. We generalize the flow equation technique, first introduced by Wegner, to the disordered system and use it to study the model and elucidate the character of this transition. This method allows us to efficiently compute the eigenvalues and local observables. We follow, analytically and numerically, the flow of the coupling distributions for the different exponents as a function of the flow-time and look for signatures of the two distinct phases as well as a characterization of the critical point.
Anderson's considerations on the flow of superfluid helium: Some offshoots
Varoquaux, Eric
2015-07-01
Nearly five decades have elapsed since the seminal 1966 paper of P. W. Anderson on the flow of superfluid helium, 4He at that time. Some of his "considerations"—the role of the quantum phase as a dynamical variable, the interplay between the motion of quantized vortices and potential superflow, its incidence on dissipation in the superfluid and the appearance of critical velocities, the quest for the hydrodynamic analogs of the Josephson effects in helium—and the way they have evolved over the past half century are recounted in this review. But it is due to key advances on the experimental front that phase slippage could be harnessed in the laboratory, leading to a deeper understanding of superflow, vortex nucleation, the various intrinsic and extrinsic dissipation mechanisms in superfluids, macroscopic quantum effects, and the superfluid analog of both ac and dc Josephson effects—pivotal concepts in superfluid physics—have been performed. Some of the experiments that have shed light on the more intimate effect of quantum mechanics on the hydrodynamics of the dense heliums are surveyed, including the nucleation of quantized vortices both by Arrhenius processes and by macroscopic quantum tunneling, the setting up of vortex mills, and superfluid interferometry.
Magnetic flux creep in HTSC and Anderson-Kim theory
International Nuclear Information System (INIS)
Lykov, A.N.
2014-01-01
The theoretical and experimental data on flux creep in high-temperature superconductors (HTSC) were analyzed in the review paper. On the one hand, the main attention is paid to the most striking experimental results which have had a significant influence on the investigations of flux creep in HTSC. On the other hand, the analysis of theoretical studies is concentrated on the works, which explain the features of flux creep on the basis of the Anderson-Kim (AK) theory modifications, and received previously unsufficient attention. However, it turned out that the modified AK theory could explain a lot of features of flux creep in HTSC: the scaling behaviour of current-voltage curves of HTSC, the finite rate of flux creep at ultra low temperatures, the logarithmic dependence of effective pinning potential as a function of transport current and its decrease with temperature. The harmonic potential field which is used in this approach makes it possible to solve accurately the both problems: viscous vortex motion and flux creep in this field. Moreover the distribution of pinning potential and the interaction of vortices with each other are taken into account in the approach. Thus, the modification of the AK theory consists, essentially, in its detailed elaboration and approaching to real situations in superconductors
What should the Price--Anderson Act accomplish
International Nuclear Information System (INIS)
Kane, G.L.
1977-01-01
A historical review of the Price-Anderson Act's goals is followed by recommendations for amendments to improve guarantees of public safety. Failures of the original Act are identified as its failure to cover some accident situations appropriately and to provide incentives for promoting public safety. Legislation should correct these problems and be extended to all energy areas. Legislation based on worst-case situations is not found to be meaningful in terms of increasing safety or estimating comprehensive compensation because it relies on invalidated assumptions, which are still useful in safety awareness. Legislation could take the direction of putting 1.5 percent of the reactor cost into a fund, with the vendor and licensee contributing equal parts. When an incident occurs at any reactor, another one percent is put in by every reactor plus a $1 million penalty proportioned among those responsible. The Federal government would cover amounts above the fund, which would have no limit. Compensation to public funds by the industry would be a social decision based on the social and economic impact
QCD constituent counting rules for neutral vector mesons
Brodsky, Stanley J.; Lebed, Richard F.; Lyubovitskij, Valery E.
2018-02-01
QCD constituent counting rules define the scaling behavior of exclusive hadronic scattering and electromagnetic scattering amplitudes at high momentum transfer in terms of the total number of fundamental constituents in the initial and final states participating in the hard subprocess. The scaling laws reflect the twist of the leading Fock state for each hadron and hence the leading operator that creates the composite state from the vacuum. Thus, the constituent counting scaling laws can be used to identify the twist of exotic hadronic candidates such as tetraquarks and pentaquarks. Effective field theories must consistently implement the scaling rules in order to be consistent with the fundamental theory. Here, we examine how one can apply constituent counting rules for the exclusive production of one or two neutral vector mesons V0 in e+e- annihilation, processes in which the V0 can couple via intermediate photons. In the case of a (narrow) real V0, the photon virtuality is fixed to a precise value s1=mV02, thus treating the V0 as a single fundamental particle. Each real V0 thus contributes to the constituent counting rules with NV0=1. In effect, the leading operator underlying the V0 has twist 1. Thus, in the specific physical case of single or double on-shell V0 production via intermediate photons, the predicted scaling from counting rules coincides with vector-meson dominance (VMD), an effective theory that treats V0 as an elementary field. However, the VMD prediction fails in the general case where the V0 is not coupled through an elementary photon field, and then the leading-twist interpolating operator has twist NV 0=2 . Analogous effects appear in p p scattering processes.
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.)
Electro- and chromomagnetism in the charm meson spectrum
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).
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.)
Isospin symmetry violation, meson production and η-nucleus ...
Indian Academy of Sciences (India)
Meson production; meson–nucleus interaction; charge symmetry. PACS Nos 13.60.Le; 13.75.-n. 1. Introduction ... sibility to investigate isospin symmetry violation in the pseudoscalar meson sector is by comparing the cross-section of the .... A test measurement was performed with this set-up and more measurements are in ...
{pi}{eta} pair hard electroproduction and exotic hybrid mesons
Energy Technology Data Exchange (ETDEWEB)
Anikin, I.V. [LPT, Universite Paris-Sud, 91405-Orsay, France, UMR 8627 du CNRS (France); BLTP, JINR, 141980 Dubna (Russian Federation); CPHT, Ecole Polytechnique, 91128 Palaiseau, France, UMR 7644 du CNRS (France); Pire, B. [CPHT, Ecole Polytechnique, 91128 Palaiseau, France, UMR 7644 du CNRS (France); Szymanowski, L. [Soltan Institute for Nuclear Studies, Warsaw (Poland) and Univ. de Liege, B-4000 Liege (Belgium); Teryaev, O.V. [BLTP, JINR, 141980 Dubna (Russian Federation); Wallon, S. [LPT, Universite Paris-Sud, 91405-Orsay, France, UMR 8627 du CNRS (France)
2005-06-13
We show that hard electroproduction is a promising way to study exotic hybrid mesons, in particular through the hybrid decay channel H->{pi}{eta}. We discuss the {pi}{eta} generalized distribution amplitude, calculate the production amplitude and propose a forward-backward asymmetry as a signal for the hybrid meson production.
πη pair hard electroproduction and exotic hybrid mesons
International Nuclear Information System (INIS)
Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.
2005-01-01
We show that hard electroproduction is a promising way to study exotic hybrid mesons, in particular through the hybrid decay channel H->πη. We discuss the πη generalized distribution amplitude, calculate the production amplitude and propose a forward-backward asymmetry as a signal for the hybrid meson production
Modification of the omega-meson lifetime in nuclear matter
Kotulla, M.; Trnka, D.; Muehlich, P.; Anton, G.; Bacelar, J. C. S.; Bartholomy, O.; Bayadilov, D.; Beloglazov, Y. A.; Bogendoerfer, R.; Castelijns, R.; Crede, V.; Dutz, H.; Ehmanns, A.; Elsner, D.; Ewald, R.; Fabry, I.; Fuchs, M.; Essig, K.; Funke, Ch.; Gothe, R.; Gregor, R.; Gridnev, A. B.; Gutz, E.; Hoeffgen, S.; Hoffmeister, P.; Horn, I.; Hoessl, J.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Klein, Frank; Klein, Fritz; Klempt, E.; Konrad, M.; Kopf, B.; Krusche, B.; Langheinrich, J.; Loehner, H.; Lopatin, I. V.; Lotz, J.; Lugert, S.; Menze, D.; Messchendorp, J. G.; Mertens, T.; Metag, V.; Mosel, U.; Nanova, M.; Novotny, R.; Ostrick, M.; Pant, L. M.; van Pee, H.; Pfeiffer, M.; Roy, A.; Radkov, A.; Schadmand, S.; Schmidt, Ch.; Schmieden, H.; Schoch, B.; Shende, S.; Suft, G.; Sumachev, V. V.; Szczepanek, T.; Suele, A.; Thoma, U.; Varma, R.; Walther, D.; Weinheimer, Ch.; Wendel, Ch.
2008-01-01
Information on hadron properties in the nuclear medium has been derived from the photoproduction of omega mesons on the nuclei C, Ca, Nb, and Pb using the Crystal Barrel/TAPS detector at the ELSA tagged photon facility in Bonn. The dependence of the omega-meson cross section on the nuclear mass
Meson Spectra: Power Law Potential Model in the Dirac Equation ...
African Journals Online (AJOL)
A single mass-spectra potential model has been used to predict the spectra of both light and heavy mesons (including leptonic decay-widths) in the Dirac equation. In fact a power law potential has been proposed with effective power where is the mass of the constituent quarks (in GeV) of the mesons considered.
Jet structure in e+e- meson production
International Nuclear Information System (INIS)
Kitazoe, T.; Hama, S.
1977-01-01
The matrix elements of the reaction e + e - → nπ are expressed in terms of overlap integral of outcoming meson Bethe-Salpeter (B-S) amplitude. Since the B-S amplitudes of high energy mesons receive a strong Lorentz contraction, the overlap integral imposes a restriction on the outcoming momenta and predicts that the meson momenta must be separated into two narrow jets. A maximum of the overlap integral predicts a special type of distribution for meson momenta and charges in a jet, which can be tested by experiment. As the strong ordering low derived there gives no interference between the final meson states, the meson production cross sections are interpreted as quark and antiquark production by a virtual γ and their subsequent cascade decays. It is shown that the quark in this interpretation is purely light-like and has nothing to do with real quark mass. An inclusion of a vector meson in a jet gives a correct angular dependence of the jet axis and incorporates the spin 1 / 2 nature of the light-like quark. A scaling low is also predicted for the momentum distributions of mesons emitted by the light-like quark
SU(3) symmetry in leptonic decays of pseudoscalar mesons
International Nuclear Information System (INIS)
Bohm, A.; Igarashi, M.; Werle, J.
1976-02-01
A short report of the present status of SU(3) symmetry in leptonic decays of pseudoscalar mesons is given including some new results. All the more involved calculations are omitted. It is found that this model works quite well in the case of leptonic decays of pseudoscalar mesons
First measurement of the B S meson mass
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.
Photoproduction of $D^{* \\pm}$ and $D^0$ Mesons
Energy Technology Data Exchange (ETDEWEB)
Jaross, Glen Richard [Illinois U., Urbana
1991-01-01
The charmed mesons D0 and Dd have been observed in photon-nucleus collisions at the FNAL ·wide Band Laboratory. A sample of 5500 inclusive $D^0$ events and $1400 D^\\pm \\to D^0 \\pi^{\\pm}$ events were used to study charm production mechanisms and $D^0$ meson decay dynamics....
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
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
Measurements of the $B$ meson production cross-sections at LHCb
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...
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
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)
Mesonic and isobar modes in matter
Energy Technology Data Exchange (ETDEWEB)
Riek, Felix C.
2007-07-01
Experiments with heavy ion collisions, like the ones performed at the GSI, are a tool to gain insight in the structure of matter. One key point needed to understand the experimental data is the theoretical description of the in medium properties of mesons and baryons. In this thesis we first developed a self-consistent description for the light vector mesons, {rho} and {omega}, and the pion at finite temperature and in a baryon free environment. A generalisation of these calculations towards finite densities mandatorily needs a reliable description for the pion and the {delta}(1232) resonance. Here we extended the approaches discussed in literature by the inclusion of vertex corrections and a selfconsistent and completely relativistic description. Within these models we were able to show that even at high temperatures the {rho}-meson properties are not changed dramatically when temperature effects are considered only. In contrast to this the behaviour of the pion and the {delta}-isobar is dramatically changed a finite density. The isobar mass-shift is given by an appropriate choice of the mean-fields. Therefore we can not draw a final conclusion about such shifts within our model. In order to do so more calculations, especially of the photo absorption on the nucleus, have to be performed. A further aspect of the calculations presented is that due to a consistent consideration of vertex corrections we were able to achieve a description of the {delta}-resonance without the usually used soft formfactor. This is especially important for the in-medium calculations because only in this way we can guarantee that soft modes of the spectrum are treated consistently. The techniques developed within this thesis allow for a straight forward generalisation of the presented models with respect to the consideration of more resonances or couplings. Doing so the here obtained description of the in-medium properties of the considered particles can be refined. (orig.)
Mesonic and isobar modes in matter
International Nuclear Information System (INIS)
Riek, Felix C.
2007-01-01
Experiments with heavy ion collisions, like the ones performed at the GSI, are a tool to gain insight in the structure of matter. One key point needed to understand the experimental data is the theoretical description of the in medium properties of mesons and baryons. In this thesis we first developed a self-consistent description for the light vector mesons, ρ and ω, and the pion at finite temperature and in a baryon free environment. A generalisation of these calculations towards finite densities mandatorily needs a reliable description for the pion and the Δ(1232) resonance. Here we extended the approaches discussed in literature by the inclusion of vertex corrections and a selfconsistent and completely relativistic description. Within these models we were able to show that even at high temperatures the ρ-meson properties are not changed dramatically when temperature effects are considered only. In contrast to this the behaviour of the pion and the Δ-isobar is dramatically changed a finite density. The isobar mass-shift is given by an appropriate choice of the mean-fields. Therefore we can not draw a final conclusion about such shifts within our model. In order to do so more calculations, especially of the photo absorption on the nucleus, have to be performed. A further aspect of the calculations presented is that due to a consistent consideration of vertex corrections we were able to achieve a description of the Δ-resonance without the usually used soft formfactor. This is especially important for the in-medium calculations because only in this way we can guarantee that soft modes of the spectrum are treated consistently. The techniques developed within this thesis allow for a straight forward generalisation of the presented models with respect to the consideration of more resonances or couplings. Doing so the here obtained description of the in-medium properties of the considered particles can be refined. (orig.)
Multiple production of mesons in Au+Au and Pb+Pb collisions
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).
Study of the exclusive production of the Meson $ \\chi_{c0}$ in CMS / LHC Experiment
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
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 a^{2} tadpole-improved staggered sea quarks and tadpole-improved Lüscher-Weisz gluons. We use the a^{2} 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.
Intersections between particle and nuclear physics
International Nuclear Information System (INIS)
Bunce, G.M.
1988-01-01
This report contains papers from an AIP conference on the intersections between particle and nuclear physics. Some of the general topics covered are: Accelerator physics; Antiproton physics; Electron and muon physics; Hadron scattering; Hadron spectroscopy; Meson and lepton decays; Neutrino physics; Nonaccelerator and astrophysics; Relativistic heavy-ion physics; and Spin physics. There are 166 papers that will be processed separately
Recent developments at the TRIUMF meson factory
International Nuclear Information System (INIS)
Craddock, M.K.
1976-10-01
The TRIUMF meson factory, which is based on a 6-sector isochronous cyclotron accelerating H - ions to 520 MeV, has been operating since December 1974. Two proton beams are extracted simultaneously to feed the two experimental areas. Characteristics of the beams and beam lines are given. Work is also proceeding on (i) additional beam lines, (ii) a 180 kW beam dump and thermal neutron source, (iii) a medium resolution proton spectrometer, and (iv) adding third harmonic flat-topping to the RF to permit separation of the internal orbits and reduction of the energy spread of the extracted beam to 0.1 MeV. (author)
Tensor glueball-meson mixing phenomenology
International Nuclear Information System (INIS)
Burakovsky, L.; Page, P.R.
2000-01-01
The overpopulated isoscalar tensor states are sifted using Schwinger-type mass relations. Two solutions are found: one where the glueball is the f J (2220), and one where the glueball is more distributed, with f 2 (1820) having the largest component. The f 2 (1565) and f J (1710) cannot be accommodated as glueball-(hybrid) meson mixtures in the absence of significant coupling to decay channels. f 2 '(1525)→ππ is in agreement with experiment. The f J (2220) decays neither flavour democratically nor is narrow. (orig.)
Higgs scalar in vector meson decays
International Nuclear Information System (INIS)
Frampton, P.H.; Wada, W.W.
1978-01-01
For the (anti tt) bound-state which is designated T, expected to be discovered shortly, the leptonic and hadronic decay widths, and the production cross section in e + e - annihilation are studied. For both Y(9.5,anti bb) and T, the decay into Higgs scalar plus photon is calculated, employing a triangle diagram estimate for the dependence of this decay matrix element on the Higgs mass. Provided that the Higgs mass is less than the masses of the vector mesons, the decay should be observable
Spectroscopic properties of the B meson
Directory of Open Access Journals (Sweden)
Devlani Nayneshkumar
2015-01-01
Full Text Available Investigation of the B(bq̄; q = u, d meson properties is carried out using variational method within phenomenological quark antiquark potential(coulomb plus power model using the Gaussian wave function. O(1/m correction to the potential energy term and relativistic corrections to the kinetic energy term of the hamiltonian are incorporated. Spin-orbit, spin-spin and tensor interactions are employed to obtain the mass spectra. Various other properties such as the decay constants, e1 and m1 transitions are also obtained
Isoscalar meson spectroscopy from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Jozef Dudek, Robert Edwards, David Richards, Christopher Thomas, Balint Joo, Michael Peardon
2011-06-01
We extract to high statistical precision an excited spectrum of single-particle isoscalar mesons using lattice QCD, including states of high spin and, for the first time, light exotic JPC isoscalars. The use of a novel quark field construction has enabled us to overcome the long-standing challenge of efficiently including quark-annihilation contributions. Hidden-flavor mixing angles are extracted and while most states are found to be close to ideally flavor mixed, there are examples of large mixing in the pseudoscalar and axial sectors in line with experiment. The exotic JPC isoscalar states appear at a mass scale comparable to the exotic isovector states.
Decay constants of heavy-light mesons
International Nuclear Information System (INIS)
Allton, C.R.; Crisafulli, M.; Lubicz, V.; Martinelli, G.; Salina, G.; Bartoloni, A.; Battista, C.; Cabasino, S.; Cabibbo, N.; Marzano, F.; Paolucci, P.S.; Pech, J.; Rapuano, F.; Sarno, R.; Todesco, G.M.; Torelli, M.; Tross, W.; Vicini, P.
1994-01-01
The decay constants of the heavy-light pseudoscalar mesons are studied in a high statistics run using the Wilson action at β=6.0 and β=6.2, and the clover action at β=6.0. The systematics of O(a) discretisation errors are discussed. Our best estimates of the decay constants are: f D =218(9) MeV, f D /f D s =1.11(1) and we obtain preliminary values for f B . (orig.)
Large acceptance spectrometers for π0 mesons
International Nuclear Information System (INIS)
Awes, T.C.; Ferguson, R.L.; Obenshain, F.E.
1984-01-01
A spectrometer composed of lead-oxide loaded glass blocks has been constructed for detection of neutral pi mesons emitted in low energy heavy ion reactions. The spectrometer detects the Cerenkov radiation emitted when the high energy photons (Eγ approx. 70 MeV) resulting from π 0 decay create electron-position pairs in the glass, initiating electromagnetic showers. A geometric acceptance of better than 5% of 4π is possible; the π 0 detection efficiency varies between this value at T/sub π/ = 0 MeV and 1% for T/sub π/ approx. 100 MeV
2010-02-24
... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY Proposed CERCLA Administrative Settlement; Anderson-Calhoun Mine and Mill Site, Leadpoint, WA AGENCY: Environmental Protection Agency (EPA). ACTION: Notice; request for public comment. SUMMARY: In...
Steady-State Anderson Accelerated Coupling of Lattice Boltzmann and Navier–Stokes Solvers
Atanasov, Atanas
2016-10-17
We present an Anderson acceleration-based approach to spatially couple three-dimensional Lattice Boltzmann and Navier–Stokes (LBNS) flow simulations. This allows to locally exploit the computational features of both fluid flow solver approaches to the fullest extent and yields enhanced control to match the LB and NS degrees of freedom within the LBNS overlap layer. Designed for parallel Schwarz coupling, the Anderson acceleration allows for the simultaneous execution of both Lattice Boltzmann and Navier–Stokes solver. We detail our coupling methodology, validate it, and study convergence and accuracy of the Anderson accelerated coupling, considering three steady-state scenarios: plane channel flow, flow around a sphere and channel flow across a porous structure. We find that the Anderson accelerated coupling yields a speed-up (in terms of iteration steps) of up to 40% in the considered scenarios, compared to strictly sequential Schwarz coupling.
Modified Anderson orthogonality catastrophe power law in the presence of shell structure
Bandopadhyay, Swarnali; Hentschel, Martina
2011-01-01
We study Anderson orthogonality catastrophe (AOC) for parabolic quantum dots and focus on the effects of degeneracies, realized through the inherent shell structure of their energy levels that can be lifted through an external magnetic field, on the Anderson overlap. We find rich and interesting behaviors as a function of the strength and position of the perturbation, the system size, and the applied magnetic field. In particular, even for weak perturbations, we observe a pronounced AOC that is related to the degeneracy of energy levels. Most importantly, the power-law decay of the Anderson overlap as a function of the number of particles is modified in comparison to the metallic case due to the rearrangement of the energy-level shell structure. We support our analytical results by numerical calculations and also study the distribution of Anderson overlaps.
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
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.
Anderson localization for 2D discrete Schrödinger operator with random vector potential
Klopp, F
2002-01-01
We prove the Anderson localization near the bottom of the spectrum for two dimensional discrete Schr{\\"o}dinger operators with a class of random vector potentials and no scalar potentials. Main lemmas are the Lifshitz tail and the Wegner estimate on the integrated density of states. Then, the Anderson localization, i.e., the pure point spectrum with exponentially decreasing eigenfunctions, is proved by the standard multiscale argument.
Wegner estimates, Lifshitz tails, and Anderson localization for Gaussian random magnetic fields
Ueki, Naomasa
2016-07-01
The Wegner estimate for the Hamiltonian of the Anderson model for the special Gaussian random magnetic field is extended to more general magnetic fields. The Lifshitz tail upper bounds of the integrated density of states as analyzed by Nakamura are reviewed and extended so that Gaussian random magnetic fields can be treated. By these and multiscale analysis, the Anderson localization at low energies is proven.
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
Attractive Hubbard model with disorder and the generalized Anderson theorem
International Nuclear Information System (INIS)
Kuchinskii, E. Z.; Kuleeva, N. A.; Sadovskii, M. V.
2015-01-01
Using the generalized DMFT+Σ approach, we study the influence of disorder on single-particle properties of the normal phase and the superconducting transition temperature in the attractive Hubbard model. A wide range of attractive potentials U is studied, from the weak coupling region, where both the instability of the normal phase and superconductivity are well described by the BCS model, to the strong-coupling region, where the superconducting transition is due to Bose-Einstein condensation (BEC) of compact Cooper pairs, formed at temperatures much higher than the superconducting transition temperature. We study two typical models of the conduction band with semi-elliptic and flat densities of states, respectively appropriate for three-dimensional and two-dimensional systems. For the semi-elliptic density of states, the disorder influence on all single-particle properties (e.g., density of states) is universal for an arbitrary strength of electronic correlations and disorder and is due to only the general disorder widening of the conduction band. In the case of a flat density of states, universality is absent in the general case, but still the disorder influence is mainly due to band widening, and the universal behavior is restored for large enough disorder. Using the combination of DMFT+Σ and Nozieres-Schmitt-Rink approximations, we study the disorder influence on the superconducting transition temperature T c for a range of characteristic values of U and disorder, including the BCS-BEC crossover region and the limit of strong-coupling. Disorder can either suppress T c (in the weak-coupling region) or significantly increase T c (in the strong-coupling region). However, in all cases, the generalized Anderson theorem is valid and all changes of the superconducting critical temperature are essentially due to only the general disorder widening of the conduction band
Mesonic states in quantum spin ice
Petrova, Olga; Moessner, Roderich; Sondhi, Shivaji
We study magnetic monopoles in quantum spin ice, whose dynamics is induced by a transverse field term. We find that the bipartiteness of the state graph of the model and the local spin ice rule constraints result in the presence of an approximately flat band at the classical energy of the nearest neighbor monopole pair. The degeneracy of the so-called mesonic states making up the flat band splits at the same order as the spin ice ground state manifold. We show that the mesonic states result in a crisp neutron scattering signature of magnetic monopoles in the system, and that the momentum dependence of the structure factor may allow for the detection of quantum fluctuations in a spin ice system near the classical limit. This work was supported by the Helmholtz Virtual Institute New States of Matter and their Excitations, NSF Grant No. DMR-1311781; Alexander von Humboldt Foundation; DFG via SFB 1143; and LabEX ENS-ICFP: ANR-10-LABX-0010/ANR-10-IDEX-0001-02 PSL*.
High-energy photoproduction of neutral mesons
Charity, Tim
1987-01-01
This thesis presents results from the first full period of data-taking of the experiment WA69 at the Omega^'^ectrometer, CERN, Geneva. The experiment used a tagged photon beam of energy 60-180 GeV incident on a liquid hydrogen target to study photoproduction of hadronic states. The various components of the experiment are described, with particular emphasis on the electromagnetic calorimeters, and the associated offline software for event reconstruction and acceptance calculation. The performance of the outer calorimeter is discussed, and the pi^0 detection and reconstruction efficiency is examined by comparison with pi^{+/- } production. Searches for photoproduction of neutral meson states reveal a clear signal for the pi^0, eta^0 , and omega^0 mesons. The cross-section for elastic omega^0 production is estimated, and found to be consistent with the established value of 1 mub. The cross-section for inclusive pi^0 and eta^0 production is studied using the variable Feynman-x (x_{F }), and pi^0 production as a ...
Light-Meson Spectroscopy with COMPASS
Grube, Boris
2010-01-01
COMPASS is a multi-purpose fixed-target experiment at the CERN Super Proton Synchrotron investigating the structure and spectrum of hadrons. One primary goal is the search for new hadronic states, in particular spin-exotic mesons and glueballs. After a short pilot run in 2004 with a 190 GeV/c $\\pi^-$ beam on a Pb target, which showed a significant spin-exotic $J^{PC} = 1^{-+}$ resonance consistent with the controversial $\\pi_1(1600)$, COMPASS collected large data samples with negative and positive hadron beams on H$_2$, Ni, W, and Pb targets in 2008 and 2009. We present results from a partial-wave analysis of diffractive dissociation of 190 GeV/c $\\pi^-$ into $\\pi^-\\pi^+\\pi^-$ final states on Pb and H$_2$ targets with squared four-momentum transfer in the range 0.1 < t' < 1 (GeV/c)^2. This reaction provides clean access to the light-quark meson spectrum up to masses of 2.5 GeV/c^2. A first comparison of the data from Pb and H$_2$ target shows a strong target dependence of the production strength of stat...
Light-Meson Spectroscopy at COMPASS
Krinner, Fabian
2017-01-01
The goal of the COMPASS experiment at CERN is to study the structure and spectroscopy of hadrons. The two-stage spectrometer has large acceptance and covers a wide kinematic range for charged as well as neutral particles allowing to access a wide range of reactions. Light mesons are studied with negative (mostly $\\pi^-$) and positive ($p$, $\\pi^+$) hadron beams with a momentum of $190\\,\\text{GeV}/c$. The light-meson spectrum is measured in different final states produced in diffractive dissociation reactions with squared four-momentum transfer $t$ to the target between $0.1$ and $1.0\\,(\\text{GeV}/c)^2$. The flagship channel is the $\\pi^-\\pi^+\\pi^-$ final state, for which COMPASS has recorded the currently world's largest data sample. These data not only allow us to measure the properties of known resonances with high precision, but also to search for new states. Among these is a new axial-vector signal, the $a_1(1420)$, with unusual properties. The findings are confirmed by the analysis of the $\\pi^-\\pi^0\\pi^...
Precision measurement of $D$ meson mass differences
INSPIRE-00258707; Abellan Beteta, C; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Elsby, D; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skwarnicki, T; Smith, N A; Smith, E; Smith, M; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A
2013-01-01
Using three- and four-body decays of $D$ mesons produced in semileptonic $b$-hadron decays, precision measurements of $D$ meson mass differences are made together with a measurement of the $D^{0}$ mass. The measurements are based on a dataset corresponding to an integrated luminosity of 1.0 fb$^{-1}$ collected in $pp$ collisions at 7~TeV. Using the decay $D^0 \\rightarrow K^{+} K^{-} K^{-} \\pi^{+}$, the $D^0$ mass is measured to be \\begin{alignat*}{3} M(D^0) \\phantom{ghd} &=&~1864.75 \\pm 0.15 \\,({\\rm stat}) \\pm 0.11 \\,({\\rm syst}) \\, \\textrm{MeV}/c^2. \\end{alignat*} The mass differences \\begin{alignat*}{3} M(D^{+}) - M(D^{0}) &=& 4.76 \\pm 0.12 \\,({\\rm stat}) \\pm 0.07 \\,({\\rm syst}) \\, \\textrm{MeV}/c^2, \\\\ M(D^{+}_s) - M(D^{+}) &=& \\phantom{00}98.68 \\pm 0.03 \\,({\\rm stat}) \\pm 0.04 \\,({\\rm syst}) \\, \\textrm{MeV}/c^2 \\end{alignat*} are measured using the $D^0 \\rightarrow K^{+} K^{-} \\pi^{+} \\pi^{-}$ and $D^{+}_{(s)} \\rightarrow K^{+}K^{-} \\pi^{+}$ modes.
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
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
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.
Energy Technology Data Exchange (ETDEWEB)
Waintal, X
1999-09-10
We study the quantum mechanics of interacting particles in a disordered system, and in particular, what happens to Anderson localisation when interaction is taken into account. In the first part,one looks at the excited states of two particles in one dimension. For this model, it has been shown (Shepelyansky 1994) that a local repulsive interaction can partially destroy Anderson localisation. Here, we show that this model has similarities with the three-dimensional Anderson model at the metal-insulator transition. In particular, the maximum of rigidity obtained in the spectral statistics correspond to some intermediary statistics that cannot be described by random matrix theory neither by a Poisson statistics. The wave functions show a multifractal behaviour and the spreading of the center of mass of a wave packet is logarithmic in time. The second part deals with the ground state of a finite density of spinless fermions in two dimensions. After the scaling theory of localisation, it was commonly accepted that there was no metal in two dimensions. This idea has been challenged by the observation of a metal-insulator transition in low density electron gas (Kravchenko et al. 1994). We propose a scenario in which a metallic phase occurs between the Anderson insulator and the pinned Wigner crystal. This intermediate phase is characterized by an alignment of the local currents flowing in the system. (author)
Evidence for the anti Bs0 meson in Z0 decays at the ALEPH detector
International Nuclear Information System (INIS)
Schroeder, J.
1993-03-01
In the framework of the standard model of elementary particle physics it is expected that in the nature arbitrary quark-antiquark combinations of the six different quark types (t, b, c, s, u, d) are observable, so also the anti B 0 s meson, a bound state of a b and a anti s quark. In the present thesis the existence of this hitherto not observed meson is detected by means of its semileptonic decay anti B 0 s →D s + Xl - anti ν. For this about 420,000 Z 0 boson decays, which were taken up by the ALEPh detector at the e + e - -storage ring LEP at the CERN in the years 1990/91, were searched for D s + l - -combinations. The D s mesons were thereby detected via the decay chain D s → φπ - *+ φ → K - +K - . Kinematical cuts, which suppress the physical background from decays of the light B mesons, make the extraction of a signal of 12.8 ± 4.0 events possible. This signal can only with a probability P = 0.0421 0,0846/0.0000% result from fluctuations of the physical and combinatorical background. The result can by this be considered as evidence for the existence of the anti B s 0 . The error regards the possible, hitherto not confirmed existence of the decay of the light B meson B → D s + Kl - anti ν. From the height of the signal the branching ratio f s xP( anti B 0 s → D s Xlν) = 1,40 ± (0,54)stat. ± (0,30)syst. ± 0,00 / 0,27 can be determined. Herteby is f s the probability to produce in the fragmentation of s anti s pair, P( anti B 0 s → D s Xlν) the semileptonic branching ratio f the anti B 0 s . The last error results again from the possible existence of the decay B → D ss s Kl - anti ν. (orig.) [de
Diffractive vector meson production in deep inelastic scattering
International Nuclear Information System (INIS)
Kamps, M. de.
1997-01-01
This thesis seeks to bring comfort to those who are appalled by the usual high level of violence in high energy physics. Although also here we engage in the customary vandalistic smashing together of two particles, the reaction we will study has a happy end in store for both of them. The subject of this thesis will be the reaction: e + p→e + pV where V is one of the vector mesons ρ, ω, φ, J/ψ. We will investigate the situation where the final state positron enters the ZEUS main detector, which indicates that a violent reaction has taken place between the initial state particles, but nevertheless the proton does not break up. The violence with which the positron is scattered characterises the reaction as a Deep Inelastic Scattering (DIS), the fact that the proton does not break up characterises the reaction as diffractive which explains the title of the thesis. Both DIS and diffractive physics will be defined and discussed in the context of this thesis. (orig./WL)
Search for Hybrid Mesons via Photoproduction at Jefferson Lab
Eugenio, Paul
2014-09-01
Studies of meson spectra via strong decays provide insight regarding QCD at the confinement scale. These studies have led to phenomenological models 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 hybrids, exotics, multi-quarks, and glueballs. 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. Theoretical calculations indicate that photoproduction should provide an ideal hunting ground for gluonic hybrid mesons. I report on a search for photoproduced mesons using the CLAS at Jefferson Lab. CLAS has acquired the largest statistics to date for peripheral meson photoproduction at intermediate photon energies. Results on on several final states will be presented. I will conclude with a overview of future efforts to search for exotic mesons utilizing the 12 GeV CEBAF accelerator in conjunction with upgraded and new experimental facilities.
New methods for B meson decay constants and form factors from lattice NRQCD
Hughes, C.; Davies, C. T. H.; Monahan, C. J.; Hpqcd Collaboration
2018-03-01
We determine the normalization of scalar and pseudoscalar current operators made from nonrelativistic b quarks and highly improved staggered light quarks in lattice quantum chromodynamics (QCD) through O (αs) and ΛQCD/mb. We use matrix elements of these operators to extract B meson decay constants and form factors, and then compare to those obtained using the standard vector and axial-vector operators. This provides a test of systematic errors in the lattice QCD determination of the B meson decay constants and form factors. We provide a new value for the B and Bs meson decay constants from lattice QCD calculations on ensembles that include u , d , s , and c quarks in the sea and those that have the u /d quark mass going down to its physical value. Our results are fB=0.196 (6 ) GeV , fBs=0.236(7 ) GeV , and fB s/fB=1.207 (7 ), agreeing well with earlier results using the temporal axial current. By combining with these previous results, we provide updated values of fB=0.190 (4 ) GeV , fBs=0.229(5 ) GeV , and fB s/fB=1.206 (5 ).
New Methods for B Meson Decay Constants and Form Factors from Lattice NRQCD
Energy Technology Data Exchange (ETDEWEB)
Hughes, C. [Fermilab; Davies, C. T.H. [SUPA, UK; Monahan, C. J. [Washington U., Seattle
2017-11-27
We determine the normalisation of scalar and pseudoscalar current operators made from non-relativistic $b$ quarks and Highly Improved Staggered light quarks in lattice Quantum Chromodynamics (QCD) through $\\mathcal{O}(\\alpha_s)$ and $\\Lambda_{\\text{QCD}}/m_b$. We use matrix elements of these operators to extract $B$ meson decay constants and form factors, then compare to those obtained using the standard vector and axial-vector operators. This provides a test of systematic errors in the lattice QCD determination of the $B$ meson decay constants and form factors. We provide a new value for the $B$ and $B_s$ meson decay constants from lattice QCD calculations on ensembles that include $u$, $d$, $s$ and $c$ quarks in the sea and those which have the $u/d$ quark mass going down to its physical value. Our results are $f_B=0.196(6)$ GeV, $f_{B_s}=0.236(7)$ GeV and $f_{B_s}/f_B =1.207(7)$, agreeing well with earlier results using the temporal axial current. By combining with these previous results, we provide updated values of $f_B=0.190(4)$ GeV, $f_{B_s}=0.229(5)$ GeV and $f_{B_s}/f_B = 1.206(5)$.
Study of Rare Radiative B Decay to K*(1430) Meson Using the BABAR Detector
Energy Technology Data Exchange (ETDEWEB)
Guo, Qinghua; /Pennsylvania U.
2005-09-14
Radiative B Meson decay through the b {yields} s{gamma} process has been one of the most sensitive probe of new physics beyond the Standard Model, because of its importance in understanding the phenomenon of CP violation, which is believed to be necessary to explain the excess of matter over anti-matter in our universe. The inclusive picture of the b {yields} s{gamma} process is well established; however, our knowledge of the exclusive final states in radiative B meson decays is rather limited. We have investigated one of them, the exclusive, radiative B decay to the charmless K*{sub 2}(1430) meson, in a sample of 88.5 x 10{sup 6} B{bar B} events with the BABAR detector at the PEP-II storage ring. We present a measurement of the branching fractions {Beta}(B{sup 0} {yields} K*{sub 2}(1430){sup 0}{gamma}) = (1.22 {+-} 0.25 {+-} 0.10) x 10{sup -5} and {Beta}(B{sup +} {yields} K*{sub 2}(1430){sup +}){gamma} = (1.45 {+-} 0.40 {+-} 0.15) x 10{sup -5}, where the first error is statistical and the second systematic. In addition, we have performed the first search for direct CP violation in this decay with the measured asymmetry in B{sup 0} {yields} K*{sub 2}(1430){sup 0}{gamma} of {Alpha}{sub CP} = -0.08 {+-} 0.15 {+-} 0.01.
Nonlinear approach to NN interactions using self-interacting meson fields
International Nuclear Information System (INIS)
Jaede, L.; von Geramb, H.V.
1997-01-01
Motivated by the success of models based on chiral symmetry in NN interactions, we investigate self-interacting scalar, pseudoscalar, and vector meson fields and their impact for NN forces. We parametrize the corresponding nonlinear field equations and get analytic wavelike solutions. A probability amplitude for the propagation of particle states is calculated and applied in the framework of a boson-exchange NN potential. Using a proper normalization of the meson fields makes all self-scattering amplitudes finite. The same normalization is able to substitute for the phenomenological form factors used in conventional boson-exchange potentials and thus yields a phenomenological understanding of this part of the NN interaction. We find an empirical scaling law which relates the meson self-interaction couplings to the pion mass and self-interaction coupling constant. Our model yields np phase shifts comparable to the Bonn B potential results and deuteron properties, in excellent agreement with experimental data. copyright 1997 The American Physical Society
International Nuclear Information System (INIS)
Renard, F.M.
1981-01-01
The author discusses the role of electron-positron interactions in particle physics. Topics covered include: vector mesons; exclusive reactions and form factors; the total cross-section; multiparticle production at high energy; γγ physics; electroweak interactions and QFD tests; strong interactions and QCD tests; exotics. (A.W.)
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)
Quenched and Partially Quenched Chiral Perturbation Theory for Vector and Tensor Mesons
Chow, Chi-Keung; Rey, Soo-Jong
1997-01-01
Quenched and partially quenched chiral perturbation theory for vector mesons is developed and is used to extract chiral loop correction to the $\\rho$ meson mass. Connections to fully quenched and totally unquenched chiral perturbation theory results are discussed. It is also shown that (partially) quenched perturbation theory for tensor mesons can be formulated analogously, and the chiral corrections for tensor meson masses are directly proportional to their counterparts in the vector meson s...
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)
Scattering phaseshift formulas for mesons and baryons in elongated boxes
Lee, Frank X.; Alexandru, Andrei
2018-03-01
We derive Lüscher phaseshift formulas for two-particle states in boxes elongated in one of the dimensions. Such boxes offer a cost-effective way of varying the relative momentum of the particles. Boosted states in the elongated direction, which allow wider access to energies, are also considered. The formulas for the various scenarios (moving and zero-momentum states in cubic and elongated boxes) are compared and relations between them are clarified. The results are applicable to a wide set of meson-meson and meson-baryon elastic scattering processes, with the two-particle system having equal or unequal masses.
Study of Inclusive Production of Charmonium Mesons in B Decay
The BABAR Collaboration; Aubert, B.
2002-01-01
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2003 APS The inclusive production of charmonium mesons in B meson decay has been studied in a 20.3 fb-1 data set collected by the BABAR experiment operating at the Υ(4S) resonance. Branching fractions have been measured for the inclusive production of the charmonium mesons J/ψ, ψ(2S), χc1, and χc2. The branching fractions are also presented as a function of the cen...
Collective Flow of K+ Meson within Covariant Kaon Dynamics
International Nuclear Information System (INIS)
Srisawad, P.; Zheng, Y.M.; Yan, Y.; Xing, Y.Z.
2010-01-01
Collective flow of K + mesons in heavy ion collisions at SIS energies is investigated within the covariant kaon dynamics. The theoretical results calculated by using quantum molecular dynamics reasonably reproduce properties of the K + anti-flow. This means that the features of K + collective flow clearly favor the existence of an in-medium repulsive potential for K + meson. It is also shown that the rapidity distribution of K + meson is more sensitive to the nuclear equation of state than the differential directed flow.
Antiproton-proton annihilation into charged light meson pairs within effective meson theory
Wang, Ying; Bystritskiy, Yury M.; Tomasi-Gustafsson, Egle
2017-04-01
We revisit antiproton-proton annihilation into light mesons in the energy domain relevant to the antiproton annihilation at Darmstadt (PANDA) experiment at the GSI Facility for Antiproton and Ion Research (FAIR) [2.25 (1.5 ) ≤√{s }(pL) ≤5.47 (15 ) GeV (GeV /c ) where √{s }(pL) is the total energy (the beam momentum in the laboratory frame)]. An effective meson model is developed, with mesonic and baryonic degrees of freedom. Form factors are added to take into account the composite nature of the interacting hadrons. A comparison is made with the existing data for charged pion pair production and predictions for angular distributions and energy dependence in the range 3.362 (5 ) ≤√{s }(pL) ≤4.559 (10.1 ) GeV (GeV /c ). The model is applied to π±p elastic scattering, using crossing symmetry, and to charged kaon pair production, on the basis of SU(3) symmetry. In all cases the results illustrate a nice agreement with the data.
Cross sections for inelastic meson-meson scattering via quark-antiquark annihilation
Shen, Zhen-Yu; Xu, Xiao-Ming; Weber, H. J.
2016-08-01
We study inelastic meson-meson scattering that is governed by quark-antiquark annihilation and creation involving a quark and an antiquark annihilating into a gluon, and subsequently the gluon creating another quark-antiquark pair. The resultant hadronic reactions include for I =1 : π π →ρ ρ , K K ¯→K*K¯*, K K¯*→K*K¯*, K*K ¯→K*K¯*, as well as π π →K K ¯, π ρ →K K¯*, π ρ →K*K ¯, and K K ¯→ρ ρ . In each reaction, one or two Feynman diagrams are involved in the Born approximation. We derive formulas for the unpolarized cross section, the transition amplitude, and the transition potential for quark-antiquark annihilation and creation. The unpolarized cross sections for the reactions are calculated at six temperatures, and prominent temperature dependence is found. It is due to differences among mesonic temperature dependence in hadronic matter.
Analytical and unitary approach in mesons electromagnetic form factor applications
International Nuclear Information System (INIS)
Liptaj, A.
2010-07-01
In the dissertation thesis we address several topics related to the domain of particle physics. All of them represent interesting open problems that can be connected to the elastic or transition electromagnetic form factors of mesons, the form factors being the main objects of our interest. Our ambition is to contribute to the solution of these problems and use for that purpose known analytic properties of the form factors and the unitarity condition. These two tools are very powerful in the low energy domain (such as bound states of partons), where the perturbative QCD looses its validity. This is the motivation for construction of the unitary and analytic (U and A) models of studied form factors, that enable us to get the majority of our results. We use the U and A model to evaluate the contribution of the processes e + e - → Pγ, P = π 0 , η, η to the muon magnetic anomaly a μ in the lowest order of the hadronic vacuum polarization. For the contribution a μ had,LO (π + π - ) we demonstrate, that the use of the model leads to a dramatic error reduction with respect to the results of other authors. We also get a shift in the central value in the 'correct' direction, that brings the theoretical value closer to the experimental one. This results encourages us to use the model also for the evaluation of a μ had,LO (P γ ). These contributions are smaller, however the precision of the experiment makes their evaluation necessary. We further use the U and A model of the transition form factors of π 0 , η and η ' mesons to predict the partial decay widths of these particles Γ π 0 →γγ and Γ η→γγ and Γ η ' →γγ . In this way we make an independent cross check of the PDG table values. We find an agreement in the case of Γ η→γγ and Γ η ' →γγ , even a smaller uncertainty for Γ η ' →γγ . In the case of Γ π 0 →γγ we find a disagreement that points to an interesting problem. We wonder whether it
Form factors of heavy mesons in QCD
International Nuclear Information System (INIS)
Shifman, M.A.; Vysotsky, M.I.
1980-01-01
Logarithmic corrections to form factors of mesons built from heavy quarks are dirived in the framework of quantum chromodynamics. The reactions e + e - → etasub(c)γ and H → J/PSIγ are considered as an example. A novel feature as compared to the well studied problem of the pion form factor is the existence of the transformations between the quark-antiquark state c anti c and the gluonic one. O(αsub(s)) corrections are calculated exactly. An infinite series of the leading logarithmic terms is summed up with the help of the operator technique. Apart from already known results for quark operators some new results referring to gluon operators and their mixing with the quark ones are used. Two alternative derivations of the multiplicatively renormalizable operators are given. The first one reduces to a direct computation of the mixing matrix and its diagonalization, the second derivation is based on conformal symmetry considerations
Meson spectra using relativistic quark models
International Nuclear Information System (INIS)
Eggers, M.C.
1985-01-01
The complexity of QCD has led to the use of simpler, phenomenological models for hadrons, notably potential models. A short overview of the origin, rationale, merits and demerits of such models is given. Nonrelativistic models and scaling laws are discussed using the WKB technique for illustrative purposes. The failure of nonrelativistic models to describe the lighter mesons motivates the introduction of relativistic equations. Relativistic kinematics are incorporated into a Schroedinger formalism using equations derived by A. Barut, while two-body kinematics are brought into a one-body form via a substitution related to the Todorov equation. The potential used involves a semi-analytic solution to a harmonic oscillator modified by a spin-spin interaction term. The results seem to indicate that such a harmonic oscillator is unsuitable to describe diquark systems adequately
Exotic meson decay widths using lattice QCD
International Nuclear Information System (INIS)
Cook, M. S.; Fiebig, H. R.
2006-01-01
A decay width calculation for a hybrid exotic meson h, with J PC =1 -+ , is presented for the channel h→πa 1 . This quenched lattice QCD simulation employs Luescher's finite box method. Operators coupling to the h and πa 1 states are used at various levels of smearing and fuzzing, and at four quark masses. Eigenvalues of the corresponding correlation matrices yield energy spectra that determine scattering phase shifts for a discrete set of relative πa 1 momenta. Although the phase shift data is sparse, fits to a Breit-Wigner model are attempted, resulting in a decay width of about 60 MeV when averaged over two lattice sizes having a lattice spacing of 0.07 fm
Inclusive Photoproduction of Neutral k* Mesons
Kolya, Scott Daniel
Available from UMI in association with The British Library. Requires signed TDF. This thesis presents results from the 1985 data taking of the WA69 experiment at the OMEGA spectrometer, CERN, Geneva, performed by the EGAMMA collaboration (Bonn, CERN, Lancaster, Manchester, RAL, Sheffield, Yerevan). A tagged photon beam of energy 70-170 GeV, produced through bremsstrahlung of an electron beam, was incident on a liquid hydrogen target. The OMEGA spectrometer, together with various downstream detectors, were triggered to record the resulting hadronic interactions. In this thesis the experimental apparatus and software are described, with particular emphasis on the Ring Image Cerenkov detector (RICH). Preliminary analysis of the inclusive production of neutral K*(890) mesons is presented. The RICH is used to identify kaons in the Kpi final state. The Feynman-X (X_ {F}) distributions are compared to the predictions of the quark fusion and LUND fragmentation models of low P_{t} production.
Exclusive Backward-Angle Omega Meson Electroproduction
Energy Technology Data Exchange (ETDEWEB)
Wenliang, Li [Univ. of Regina, Regina, SK (Canada)
2017-10-01
Exclusive meson electroproduction at different squared four-momenta of the exchanged virtual photon, Q^{2} , and at different four-momentum transfers, t and u, can be used to probe QCD's transition from hadronic degrees of freedom at the long distance scale to quark-gluon degrees of freedom at the short distance scale. Backward-angle meson electroproduction was previously ignored, but is anticipated to offer complimentary information to conventional forward-angle meson electroproduction studies on nucleon structure. This work is a pioneering study of backward-angle ω cross sections through the exclusive ^{1}H(e, e'p)ω reaction using the missing mass reconstruction technique. The extracted cross sections are separated into the transverse (T), longitudinal (L), and LT, TT interference terms. The analyzed data were part of experiment E01-004 (Fπ-2), which used 2.6-5.2 GeV electron beams and HMS+SOS spectrometers in Jefferson Lab Hall C. The primary objective was to detect coincidence π in the forward-angle, where the backward-angle omega events were fortuitously detected. The experiment has central Q^{2} values of 1.60 and 2.45 GeV^{2} , at W = 2.21 GeV. There was significant coverage in phi and epsilon, which allowed separation of σ_{T,L,LT,TT} . The data set has a unique u coverage of -u ~ 0, which corresponds to -t > 4 GeV^{2} . The separated σ_{T} result suggest a flat ~ 1/Q^{1.33±1.21} dependence, whereas sigma_L seems to hold a stronger 1/Q^{9.43±6.28} dependence. The σL/σ_{T} ratio indicate σ_{T} dominance at Q^{2} = 2.45 GeV^{2} at the ~90% confidence level. After translating the results into the -t space of the published CLAS data, our data show evidence of a backward-angle omega electroproduction peak at both Q^{2} settings. Previously, this phenomenon showing both forward and backward-angle peaks was only observed in the meson
Light-Meson Spectroscopy at Compass
Directory of Open Access Journals (Sweden)
Krinner Fabian
2017-01-01
The light-meson spectrum is measured in different final states produced in diffractive dissociation reactions with squared four-momentum transfer t to the target between 0.1 and 1.0 (GeV/c2. The flagship channel is the π−π+π− final state, for which Compass has recorded the currently world’s largest data sample. These data not only allow us to measure the properties of known resonances with high precision, but also to search for new states. Among these is a new axial-vector signal, the a1(1420, with unusual properties. The findings are confirmed by the analysis of the π−π0π0 final state.
Production of charmed mesons in Z decays
Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Orteu, S.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Girone, M.; Hagelberg, R.; Harvey, J.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Maggi, M.; Markou, C.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Perrodo, P.; Pusztaszeri, J.-F.; Ranjard, F.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Tomalin, I. R.; Veenhof, R.; Wachsmuth, H.; Wasserbaech, S.; Wiedemann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Bardadin-Otwinowska, M.; Barres, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Saadi, F.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Johnson, S. D.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, B.; Fouque, G.; Passalacqua, L.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Delfino, M.; Georgiopoulos, C.; Ikeda, M.; Jaffe, D. E.; Levinthal, D.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Pepe=Altarelli, M.; Salomone, S.; Colrain, P.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Thorn, S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Graefe, G.; Hanke, P.; Hepp, V.; Karger, C.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, M.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Vogl, R.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttal, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Walther, S. M.; Wanke, R.; Wolf, B.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Calvet, D.; Carr, J.; Coyle, P.; Diaconu, C.; Drinkard, J.; Etienne, F.; Nicod, D.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jakobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, G.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, H.; Stiegler, U.; Denis, R. St.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Musolino, G.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Luisiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Valassi, A.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Gao, Y.; Green, M. G.; Johnson, D. L.; March, P. V.; Medcalf, T.; Mir, Ll. M.; Quazi, I. S.; Strong, J. A.; Bertin, V.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Edwards, M.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Bobbo, B.; Pitis, L.; Ragusa, F.; Bellantoni, L.; Chen, W.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Hayes, O. J.; Nachtman, J. M.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I.; Sharma, V.; Shi, Z. H.; Turk, J. D.; Walsh, A. M.; Weber, F. V.; Wu, Sau Lan; Wu, X.; Zheng, M.; Zobernig, G.
1994-03-01
The production of charmed mesonsmathop {D^0 }limits^{( - )} , D ± , and D *± is studied in a sample of 478,000 hadronic Z decays. The production rates are measured to be 10052_2005_Article_BF01559519_TeX2GIFE1.gif begin{gathered} {Γ (Z to D^{* ± } X)}/{Γ _{had }} = 0.187 ± 0.015(exp .) ± 0.013(BR), \\ {Γ (Z to D^ ± X)}/{Γ _{had }} = 0.251 ± 0.026(exp .) ± 0.025(BR), \\ {Γ (Z to mathop {D^0 }limits^{( - )} X)}/{Γ _{had }} = 0.518 ± 0.052(exp .) ± 0.035(BR), \\ where the errors from this analysis are separated from those coming from the D branching ratios (BR). The D *± momentum distribution is extracted separately forZ to cbar c andZ to bbar b events with the help of event shape variables. It is consistent with the prediction of the JETSET Monte Carlo program after adjustment of the charm fragmentation function. Constraining the shape of theZ to bbar b contribution, the average fraction of the beam energy taken by a D * meson produced in the fragmentation of a charm quark is extracted by a parametric fit to be c =0.495±0.011±0.007. Evidence for D **0 ( D 1(2420)0 and/or D {2/*}(2460)0) production is found in theD^{* ± } π ^ mp channel, accounting for a fraction (18±5±2)% of all D *± production. The relative production of vector and pseudoscalar mesons is dicussed, together with the possible effects of D ** production. The c-quark forward-backward Z-pole asymmetry is detrmined from that of high momentum D *± to be A {/FB 0,c }=(7.7±4.4)%.
B-meson factory in the CERN-ISR tunnel
International Nuclear Information System (INIS)
Rivkin, L.
1990-01-01
This is a feasibility study of the proposed B-meson factory in the CERN ISR tunnel. Machine parameters, the lattice, interaction region, RF system, beam instabilities, vacuum system, and background radiation are discussed
Interpreting the masses of mesons in Regge phenomenology
International Nuclear Information System (INIS)
Liu, Yun-Hu; Zhang, Jian-Jun; Feng, Xue-Chao
2010-01-01
In the framework of Regge phenomenology, we first study the relations between meson masses and the parameters of the radial Regge trajectory; then we calculate the masses of N 1 S 0 , N 3 S 1 , N 1 D 2 and N 3 D 3 meson multiplets. The fact that the results given in this work are in good agreement with those given by many other different approaches and experiment indicates that the obtained relations can give a believable description for the meson mass spectrum, especially the radial excited states. The predictions may be useful for the discovery of the unobserved meson and the J P assignment of these states. Some related problems are discussed and the further work that we can do is also considered. (orig.)
Nonperturbative quark, gluon, and meson correlators of unquenched QCD
Cyrol, Anton K.; Mitter, Mario; Pawlowski, Jan M.; Strodthoff, Nils
2018-03-01
We present nonperturbative first-principle results for quark, gluon, and meson 1PI correlation functions of two-flavor Landau-gauge QCD in the vacuum. These correlation functions carry the full information about the theory. They are obtained by solving their functional renormalization group equations in a systematic vertex expansion, aiming at apparent convergence. This work represents a crucial prerequisite for quantitative first-principle studies of the QCD phase diagram and the hadron spectrum within this framework. In particular, we have computed the gluon, ghost, quark, and scalar-pseudoscalar meson propagators, as well as gluon, ghost-gluon, quark-gluon, quark, quark-meson, and meson interactions. Our results stress the crucial importance of the quantitatively correct running of different vertices in the semiperturbative regime for describing the phenomena and scales of confinement and spontaneous chiral symmetry breaking without phenomenological input.
Sigma meson production in proton-nucleus collisions
International Nuclear Information System (INIS)
Srisawad, Pornrad; Zheng, Yuming; Fuchs, C.; Faessler, A.; Yan, Yupeng; Kobdaj, Chinorat; Xing, Yongzhong
2010-01-01
The sigma meson production is investigated in p + 40 Ca and p + 208 Pb at the incident energy 1.5 GeV within the Quantum Molecular Dynamics model. The simulation results indicate a distinctive A dependence of the sigma production that the increase of A is followed by an increase of the production cross section. We find that the sigma meson production is strongly medium dependent and the produced sigma mesons decaying in a dense medium experience a stronger mass shift towards lower masses. This mass shift is an experimentally accessible observable in the final state pion pairs, which did not suffer absorption by the surrounding nucleons. It is pointed out that the ratio of measured sigma cross-sections as a function of the sigma invariant-mass from various reactions is a good probe to explore the existence of the sigma meson in dense nuclear environment. (author)
Meson masses in electromagnetic fields with Wilson fermions
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.
Improved measurement of the B 0 and B + meson lifetimes
Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J. P.; Lucotte, A.; Minard, M. N.; Odier, P.; Pietrzyk, B.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Juste, A.; Martinez, M.; Orteu, S.; Pacheco, A.; Padilla, C.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A. O.; Bonvicini, G.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Harvey, J.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Martin, E. B.; Mato, P.; Minten, A.; Miquel, R.; Mir, Ll. M.; Moneta, L.; Oest, T.; Palla, F.; Pater, J. R.; Pusztaszeri, J. F.; Ranjard, F.; Rensing, P.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Wildish, T.; Ajaltouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rossignol, J. M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Rougé, A.; Rumpf, M.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R. M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Rensch, B.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Stacey, A. M.; Williams, M. D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Betteridge, A. P.; Bowdery, C. K.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Williams, M. I.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H. G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Etienne, F.; Konstantinidis, N.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Abt, I.; Assmann, R.; Bauer, C.; Blum, W.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Jakobs, K.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H. G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; St. Denis, R.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J. F.; Heusse, Ph.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A. M.; Nikolic, I.; Park, H. J.; Park, I. C.; Schune, M. H.; Simion, S.; Veillet, J. J.; Videau, I.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Blair, G. A.; Bryant, L. M.; Cerutti, F.; Chambers, J. T.; Gao, Y.; Green, M. G.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J. F.; Roussarie, A.; Schuller, J. P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S. N.; Dann, J. H.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W. M.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Büscher, V.; Cowan, G.; Grupen, C.; Lutters, G.; Minguet-Rodriguez, J.; Rivera, F.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Rothberg, J.; Wasserbaech, S.; Armstrong, S. R.; Bellantoni, L.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T. C.; Harton, J. L.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I. J.; Sharma, V.; Walsh, A. M.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.
1996-03-01
The lifetimes of the B 0 and B + mesons have been measured with the Aleph detector at LEP, using approximately 3 million hadronic Z decays collected in the period 1991 1994. In the first of three methods, semileptonic decays of B 0 and B + mesons were partially reconstructed by identifying events containing a lepton with an associated D*- orbar D^0 meson. The second method used fully reconstructed B 0 and B + mesons. The third method, used to measure the B 0 lifetime, employed a partial reconstruction technique to identify B 0→ D*- π + X decays. The combined results are begin{gathered} tau _0 = 1.55 ± 0.06 ± 0.03 ps, \\ tau _ + = 1.58 ± 0.09 ± 0.03 ps, \\ tfrac{{tau _ + }}{{tau _0 }} = 1.03 ± 0.08 ± 0.02. \\ .
The electromagnetic mass differences of the π and K mesons
International Nuclear Information System (INIS)
Lanik, J.
1979-01-01
Within the quantum field theory relations are found for the electromagnetic mass differences of the pseudoscalar mesons. The basic Hamiltonian includes the photonic forces as well as the isotopic symmetry breaking term. (Z.J.)
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.)
Using anti pp annihilation to find exotic mesons
Energy Technology Data Exchange (ETDEWEB)
Sharpe, S.R.
1987-10-01
Present data suggests that a number of mesons have been found which cannot be accommodated in standard anti qq multiplets. Theory suggests that such exotic mesons should exist in the spectrum of Quantum Chromodynamics, but provides little guide to their properties. It is argued that a high luminosity, low energy anti pp machine would be a powerful tool with which to search for such exotics.
π-meson chanel of the LIYF AS USSR synchrocyclotron
International Nuclear Information System (INIS)
Gordeev, V.A.; Gridnev, A.B.; Koptev, V.P.; Kruglov, S.P.; Kuz'min, L.A.; Lopatin, I.V.
1976-01-01
Design and characteristics are described of a π-meson channel of a synchrocyclotron intended for implementation of the program of studying pion-nucleon interaction for energies up to 700 Mev. The channel ensures focusing of up to 10 5 π-mesons with 490 Mev energy with a spread of pulses of Δ p/p=0.06. Beam divergence does not exceed 1 deg. The experimental data are compared with computation results
Quenched scalar-meson correlator with domain wall fermions
Energy Technology Data Exchange (ETDEWEB)
Prelovsek, S.; Orginos, K
2003-05-01
We study the q-barq singlet and non-singlet scalar-meson masses using domain wall fermions and the quenched approximation. The singlet mass is found to be smaller than the non-singlet mass and indicates that the lowest singlet meson state could be lighter than 1 GeV. The two-point functions for very small quark masses are compared with expectations from the small-volume chiral perturbation theory and the presence of fermionic zero modes.
Insight into the scalar mesons from a lattice calculation
Energy Technology Data Exchange (ETDEWEB)
Alford, Mark E-mail: alford@mit.edu; Jaffe, R.L
2000-07-03
We study the possibility that the light scalar mesons are q-bar{sup 2}q{sup 2} states rather than q-barq . We perform a lattice QCD calculation of pseudoscalar meson scattering amplitudes, ignoring quark loops and quark annihilation, and find indications that for sufficiently heavy quarks there is a stable four-quark bound state with J{sup PC}=0{sup ++} and non-exotic flavor quantum numbers.
Observation and Properties of the Orbitally Excited Bs2* Meson
Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S. H.; Ahsan, M.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G. A.; Anastasoaie, M.; Ancu, L. S.; Andeen, T.; Anderson, S.; Andrieu, B.; Anzelc, M. S.; Arnoud, Y.; Arov, M.; Arthaud, M.; Askew, A.; Åsman, B.; Assis Jesus, A. C. S.; Atramentov, O.; Autermann, C.; Avila, C.; Ay, C.; Badaud, F.; Baden, A.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Banerjee, P.; Barberis, E.; Barfuss, A.-F.; Bargassa, P.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bauer, D.; Beale, S.; Bean, A.; Begalli, M.; Begel, M.; Belanger-Champagne, C.; Bellantoni, L.; Bellavance, A.; Benitez, J. A.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Biscarat, C.; Blazey, G.; Blekman, F.; Blessing, S.; Bloch, D.; Bloom, K.; Boehnlein, A.; Boline, D.; Bolton, T. A.; Borissov, G.; Bose, T.; Brandt, A.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Buchanan, N. J.; Buchholz, D.; Buehler, M.; Buescher, V.; Bunichev, S.; Burdin, S.; Burke, S.; Burnett, T. H.; Buszello, C. P.; Butler, J. M.; Calfayan, P.; Calvet, S.; Cammin, J.; Carvalho, W.; Casey, B. C. K.; Cason, N. M.; Castilla-Valdez, H.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chan, K.; Chandra, A.; Charles, F.; Cheu, E.; Chevallier, F.; Cho, D. K.; Choi, S.; Choudhary, B.; Christofek, L.; Christoudias, T.; Cihangir, S.; Claes, D.; Coadou, Y.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Crépé-Renaudin, S.; Cutts, D.; Ćwiok, M.; da Motta, H.; Das, A.; Davies, G.; de, K.; de Jong, S. J.; de La Cruz-Burelo, E.; de Oliveira Martins, C.; Degenhardt, J. D.; Déliot, F.; Demarteau, M.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Diehl, H. T.; Diesburg, M.; Dominguez, A.; Dong, H.; Dudko, L. V.; Duflot, L.; Dugad, S. R.; Duggan, D.; Duperrin, A.; Dyer, J.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Eno, S.; Ermolov, P.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Ferapontov, A. V.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Ford, M.; Fortner, M.; Fox, H.; Fu, S.; Fuess, S.; Gadfort, T.; Galea, C. F.; Gallas, E.; Galyaev, E.; Garcia, C.; Garcia-Bellido, A.; Gavrilov, V.; Gay, P.; Geist, W.; Gelé, D.; Gerber, C. E.; Gershtein, Y.; Gillberg, D.; Ginther, G.; Gollub, N.; Gómez, B.; Goussiou, A.; Grannis, P. D.; Greenlee, H.; Greenwood, Z. D.; Gregores, E. M.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guo, J.; Guo, F.; Gutierrez, P.; Gutierrez, G.; Haas, A.; Hadley, N. J.; Haefner, P.; Hagopian, S.; Haley, J.; Hall, I.; Hall, R. E.; Han, L.; Hanagaki, K.; Hansson, P.; Harder, K.; Harel, A.; Harrington, R.; Hauptman, J. M.; Hauser, R.; Hays, J.; Hebbeker, T.; Hedin, D.; Hegeman, J. G.; Heinmiller, J. M.; Heinson, A. P.; Heintz, U.; Hensel, C.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoeth, H.; Hohlfeld, M.; Hong, S. J.; Hossain, S.; Houben, P.; Hu, Y.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jain, S.; Jakobs, K.; Jarvis, C.; Jesik, R.; Johns, K.; Johnson, C.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Juste, A.; Käfer, D.; Kajfasz, E.; Kalinin, A. M.; Kalk, J. R.; Kalk, J. M.; Kappler, S.; Karmanov, D.; Kasper, P.; Katsanos, I.; Kau, D.; Kaur, R.; Kaushik, V.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. M.; Khatidze, D.; Kim, H.; Kim, T. J.; Kirby, M. H.; Kirsch, M.; Klima, B.; Kohli, J. M.; Konrath, J.-P.; Kopal, M.; Korablev, V. M.; Kozelov, A. V.; Krop, D.; Kuhl, T.; Kumar, A.; Kunori, S.; Kupco, A.; Kurča, T.; Kvita, J.; Lacroix, F.; Lam, D.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, W. M.; Leflat, A.; Lehner, F.; Lellouch, J.; Leveque, J.; Lewis, P.; Li, J.; Li, Q. Z.; Li, L.; Lietti, S. M.; Lima, J. G. R.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, Y.; Liu, Z.; Lobo, L.; Lobodenko, A.; Lokajicek, M.; Love, P.; Lubatti, H. J.; Lyon, A. L.; Maciel, A. K. A.; Mackin, D.; Madaras, R. J.; Mättig, P.; Magass, C.; Magerkurth, A.; Mal, P. K.; Malbouisson, H. B.; Malik, S.; Malyshev, V. L.; Mao, H. S.; Maravin, Y.; Martin, B.; McCarthy, R.; Melnitchouk, A.; Mendes, A.; Mendoza, L.; Mercadante, P. G.; Merkin, M.; Merritt, K. W.; Meyer, J.; Meyer, A.; Millet, T.; Mitrevski, J.; Molina, J.; Mommsen, R. K.; Mondal, N. K.; Moore, R. W.; Moulik, T.; Muanza, G. S.; Mulders, M.; Mulhearn, M.; Mundal, O.; Mundim, L.; Nagy, E.; Naimuddin, M.; Narain, M.; Naumann, N. A.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nilsen, H.; Nogima, H.; Nomerotski, A.; Novaes, S. F.; Nunnemann, T.; O'Dell, V.; O'Neil, D. C.
2008-02-01
We report the direct observation of the excited L=1 state Bs2* in fully reconstructed decays to B+K-. The mass of the Bs2* meson is measured to be 5839.6±1.1(stat)±0.7(syst)MeV/c2, and its production rate relative to the B+ meson is measured to be [1.15±0.23(stat)±0.13(syst)]%.
Meson structure in the next-to-leading order
International Nuclear Information System (INIS)
Khorramian, A.N.; Arash, F.
2001-01-01
We present here a general scheme for accessing informations about the meson structure. The idea is based on calculating the structure of a constituent quark, which is common to all hadrons. The method is applied to pion and kaon as an example. While there is only a scarce data on the ratio of up-quark valence distributions of the K + and π + mesons, our model calculation nicely agrees with the data. (orig.)
Azimuthal Distributions of K+ Mesons in Heavy-Ion Collisions
International Nuclear Information System (INIS)
Srisawad, P.; Zheng, Y.M.; Katsungnoen, O.; Limphirat, A.; Yan, Y.
2013-01-01
Strange mesons are considered to be sensitive to in-medium modifications. Theory predicts a repulsive K + N potential and an attractive K − N potential in dense matter. A repulsive K + N potential would repel the K + mesons from the bulk of the nucleons and therefore cause a preferred out-of-plane emission of K + mesons at midrapidity and a directed flow opposite to the nucleons at target and projectile rapidity. One of observables to probe in-medium effects is the azimuthal emission pattern of K + mesons in heavy ion collisions. KaoS collaboration has measured the azimuthal distributions of K + mesons in Au + Au reactions at 1.5 A GeV and Ni + Ni reactions at 1.93 A GeV. Data show that K + mesons exhibit a pronounced enhancement at ϕ=90°, i.e. perpendicular to the reaction plane. The data have also been fitted using the first two components of a Fourier series to get the directed flow v 1 and elliptic flow v 2 . We used the quantum molecular dynamics model based on the covariant kaon dynamics to simulate the Au + Au collisions at 1.5 A GeV and the Ni + Ni collisions at 1.93 A GeV, to analyze the azimuthal distributions of K + mesons, and to calculate v 1 and v 2 of K + mesons. Calculated results with a repulsive in-medium K + N potential can reasonably describe the features of KaoS data. This indicates that the azimuthal distribution is one of sensitive probes to extract information on in-medium properties at high densities. (author)
Search for the Bc(2S) meson at CMS
Alves, Bruno
2016-01-01
The work was developed during the CERN Summer Student Programme, from June 27th to September 14th. We looked for the excited state of the Bc meson that has already been found in the ATLAS experiment. Optimized cuts were obtained both for the Bc and for the Bc(2S) mesons. The final results are not conclusive, but indicate the presence of a signal. Run 2 data set (2015-2016) is required.
Magnetic dipole moments of the heavy tensor mesons in QCD
International Nuclear Information System (INIS)
Aliev, T.M.; Barakat, T.; Savci, M.
2015-01-01
The magnetic dipole moments of the D 2 , and D S 2 , B 2 , and B S 2 heavy tensor mesons are estimated in framework of the light cone QCD sum rules. It is observed that the magnetic dipole moments for the charged mesons are larger than that of its neutral counterpart. It is found that the SU(3) flavor symmetry violation is about 10 % in both b and c sectors. (orig.)
Formation of η' mesons in photon-photon collisions
International Nuclear Information System (INIS)
Uitert, B.K. van.
1986-01-01
This thesis describes an experiment performed at the positron electron storage ring PEP at the Stanford Linear Accelerator Center on the formation of the η' resonance which is observed in its decay mode ρ 0 γ, where the ρ decays into a π + π - pair. Some general features of the relatively new subject of photon-photon physics are introduced. The η' and the coupling of photons to the η' are discussed in the context of the quark model. It is shown how the mixing angle in the nonet of pseudoscalar mesons can be derived from ratios of γγ widths. The kinematics of the two-photon exchange process, the formation of the η' resonance by the two virtual photons and its subsequent electromagnetic decay into ρ 0 γ are discussed. The selected sample of events is used to determine the γγ width of the η' under the conventional assignment J P = 0 - for the η' and J P = 1 - for the ρ. The result is combined with measurements by other experiments to a world average, which is used to determine the mixing angle for the pseudoscalar nonet under various assumptions. The decay angular and energy distributions are investigated in detail. (Auth.)
Induction of spinal cord paralysis by negative pi-mesons
International Nuclear Information System (INIS)
Amols, H.I.; Yuhas, J.M.
1981-01-01
As part of an investigation on late non-neoplastic injury induced by negative pi-mesons (pions), a series of studies have been performed using pion beams for the induction of spinal cord paralysis in the Fisher 344 rat. Groups of rats were exposed to 1, 5 or 15 daily doses of peak pions or X rays. Paralysis appeared earlier after treatment with pions than after X-rays even in a comparison of groups with similar final incidences. A single dose RBE for spinal cord paralysis of 1.3 was found. The RBE rises to a value of 3.2 if the total dose is given as a series of 15 daily exposures. These RBEs are far larger than those observed using other late injury end-points, such as tubular degeneration in the kidney or fibrosis and sclerosis in the support structures of the colon for which the single dose RBE is less than 1.2. The biological and/or physical basis for the high sensitivity of the spinal cord to peak pions has not yet been resolved, but these data have suggested caution in exposing the spinal cord to peak pions in clinical trials. (author)
Mixing and CP Violation in Charm Meson Decays
Energy Technology Data Exchange (ETDEWEB)
Meadows, B; /Cincinnati U.
2010-08-26
Mixing and CP violation (CPV ) in the neutral D system were first discussed over thirty years ago but mixing was observed for the first time only very recently. Since then, these observations have been confirmed in other experiments and in other D{sup 0} decay modes. Unlike the K, B and B{sub s} systems, for which mixing was observed years earlier, the short distance ({Delta}C = 2) amplitude contributing to mixing in the D system arises from box diagrams with down- rather than up-type quarks in the loops. The d and s components are GIM-suppressed, and the b component is suppressed by the small V{sub ub} CKM coupling. In the standard model (SM), therefore, long range, non-perturbative effects, a coherent sum over intermediate states accessible to both D{sup 0} and {bar D}{sup 0}, are the main contribution to mixing. These are hard to compute reliably, however. The phenomenon of mixing in neutral meson systems has now been observed in all flavours, but only in the past year in the D{sup 0} system. The standard model anticipated that, for the charm sector, the mixing rate would be small, and also that CP violation, either in mixing or in direct decay, would be below the present levels of observability. It is hoped that further study of these phenomena might reveal signs of new physics. A review of recently available, experimental results is given.
Chiral extrapolation of lattice data for the hyperfine splittings of heavy mesons
International Nuclear Information System (INIS)
Guo, X.; Thomas, A.W.
2002-01-01
Full text: Hyperfine splittings between the heavy vector (D*, B*) and pseudoscalar (D, B) mesons have been calculated numerically in lattice QCD, where the pion mass (which is related to the light quark mass) is much larger than its physical value. Naive linear chiral extrapolations of the lattice data to the physical mass of the pion lead to hyperfine splittings which are smaller than experimental data. In order to extrapolate these lattice data to the physical mass of the pion more reasonably, we apply the effective chiral perturbation theory for heavy mesons, which is invariant under chiral symmetry when the light quark masses go to zero and heavy quark symmetry when the heavy quark masses go to infinity. This leads to a phenomenological functional form with three parameters to extrapolate the lattice data. It is found that the extrapolated hyperfine splittings are even smaller than those obtained using linear extrapolation. We conclude that the source of the discrepancy between lattice data for hyperfine splittings and experiment must lie in non-chiral physics
Spectroscopy of pseudoscalar and vector mesons and their electroweak decays
International Nuclear Information System (INIS)
Ablakulov, Kh.
1997-01-01
Proceeding from the effective action of QCD for bilocal meson fields the formula for the action describing the spectroscopy of mesons and their electroweak decays is obtained. The numerical solutions of the Salpeter equation (SE) for the qq-bound state and the Schwinger-Dyson equation (SDE) for the quark phase function are obtained with potential as sum of the oscillator and Coulomb terms. It is shown that for the oscillator potential and current quark mass m 0 0 → γγ) are 3-4 times smaller than their experimentations. This discrepancy was not removed even choosing other shapes of the potential. In order to resolve this problem the modification of the SDE, which consists in introducing the additional terms that do not change asymptotical properties of solutions of this equation is proposed. Using such modification both constant fπ and Γ(π 0 → γγ) are reproduced on a good quantitative level. The new SE for vector mesons is proposed and its solution with potential mentioned above gives the mass spectra of these mesons. Considering the τ → ρν decay the representation for leptonic decay constant of ρ meson f π , which expresses via solutions of the SDE and the proposed SE with a given potential is obtained. It is shown that the proposed SE allows to describe both the spectroscopy of vector mesons and their leptonic decay constants on a satisfactory level in comparison with the experimental values. (author)
Wigner-like crystallization of Anderson-localized electron systems with low electron densities
Slutskin, A A; Pepper, M
2002-01-01
We consider an electron system under conditions of strong Anderson localization, taking into account interelectron long-range Coulomb repulsion. We establish that at sufficiently low electron densities and sufficiently low temperatures the Coulomb electron interaction brings about ordering of the Anderson-localized electrons into a structure that is close to an ideal (Wigner) crystal lattice, provided the dimension of the system is > 1. This Anderson-Wigner glass (AWG) is a new macroscopic electron state that, on the one hand, is beyond the conventional Fermi glass concept, and on the other hand, qualitatively differs from the known 'plain' Wigner glass (inherent in self-localized electron systems) in that the random slight electron displacements from the ideal crystal sites essentially depend on the electron density. With increasing electron density the AWG is found to turn into the plain Wigner glass or Fermi glass, depending on the width of the random spread of the electron levels. It is shown that the res...
Persistence of Anderson localization in Schrodinger operators with decaying random potentials
Figotin, A; Klein, A; Müller, P
2006-01-01
We show persistence of both Anderson and dynamical localization in Schrodinger operators with non-positive (attractive) random decaying potential. We consider an Anderson-type Schr\\"odinger operator with a non-positive ergodic random potential, and multiply the random potential by a decaying envelope function. If the envelope function decays slower than $|x|^{-2}$ at infinity, we prove that the operator has infinitely many eigenvalues below zero. For envelopes decaying as $|x|^{-\\alpha}$ at infinity, we determine the number of bound states below a given energy $E<0$, asymptotically as $\\alpha\\downarrow 0$. To show that bound states located at the bottom of the spectrum are related to the phenomenon of Anderson localization in the corresponding ergodic model, we prove: ~(a)~ these states are exponentially localized with a localization length that is uniform in the decay exponent $\\alpha$; (b)~ dynamical localization holds uniformly in $\\alpha$.
Image transport through a disordered optical fibre mediated by transverse Anderson localization.
Karbasi, Salman; Frazier, Ryan J; Koch, Karl W; Hawkins, Thomas; Ballato, John; Mafi, Arash
2014-02-25
Transverse Anderson localization of light allows localized optical-beam-transport through a transversely disordered and longitudinally invariant medium. Its successful implementation in disordered optical fibres recently resulted in the propagation of localized beams of radii comparable to that of conventional optical fibres. Here we demonstrate optical image transport using transverse Anderson localization of light. The image transport quality obtained in the polymer disordered optical fibre is comparable to or better than some of the best commercially available multicore image fibres with less pixelation and higher contrast. It is argued that considerable improvement in image transport quality can be obtained in a disordered fibre made from a glass matrix with near wavelength-size randomly distributed air-holes with an air-hole fill-fraction of 50%. Our results open the way to device-level implementation of the transverse Anderson localization of light with potential applications in biological and medical imaging.
John Anderson's development of (situational) realism and its bearing on psychology today.
Hibberd, Fiona J
2009-10-01
In 1927, the Scottish philosopher John Anderson arrived in Australia to take up the chair of Philosophy at the University of Sydney. By the late 1930s, the "macrostructure" of his realist system was in place. It includes a theory of process and a substantial metaphysics, one that opposes positivism, linguistic philosophy and all forms of idealism. However, beyond Australia it remains largely unknown, despite its bearing on a number of current issues in psychology and the social sciences generally. This article outlines Anderson's transition from Hegelian idealism to realism, describes aspects of his ontology and epistemology, compares some of Anderson's ideas with Dewey's pragmatism and explains their relevance to present-day psychology.
Image transport through a disordered optical fibre mediated by transverse Anderson localization
Karbasi, Salman; Frazier, Ryan J.; Koch, Karl W.; Hawkins, Thomas; Ballato, John; Mafi, Arash
2014-02-01
Transverse Anderson localization of light allows localized optical-beam-transport through a transversely disordered and longitudinally invariant medium. Its successful implementation in disordered optical fibres recently resulted in the propagation of localized beams of radii comparable to that of conventional optical fibres. Here we demonstrate optical image transport using transverse Anderson localization of light. The image transport quality obtained in the polymer disordered optical fibre is comparable to or better than some of the best commercially available multicore image fibres with less pixelation and higher contrast. It is argued that considerable improvement in image transport quality can be obtained in a disordered fibre made from a glass matrix with near wavelength-size randomly distributed air-holes with an air-hole fill-fraction of 50%. Our results open the way to device-level implementation of the transverse Anderson localization of light with potential applications in biological and medical imaging.
Mesonic and non-mesonic branching ratios of K{sup −} absorption in the nuclear medium
Energy Technology Data Exchange (ETDEWEB)
Sekihara, Takayasu, E-mail: sekihara@post.kek.jp [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1, Oho, Ibaraki 305-0801 (Japan); Yamagata-Sekihara, Junko [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1, Oho, Ibaraki 305-0801 (Japan); Jido, Daisuke [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Kanada-En' yo, Yoshiko [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)
2013-09-20
The branching ratios of K{sup −} absorption at rest in nuclear matter are evaluated from the K{sup −} self-energy by using the chiral unitary approach for the s-wave K{sup ¯}N amplitude. We find that both the mesonic and non-mesonic absorption potentials are dominated by the Λ(1405) contributions. We also observe that the mesonic absorption ratio [π{sup −}Σ{sup +}]/[π{sup +}Σ{sup −}] increases as a function of nuclear density due to the interference between Λ(1405) and the I=1 non-resonant background, which is consistent with experimental results. The fraction of the non-mesonic absorption is evaluated to be about 30% at the saturation density. The branching ratios of the K{sup −} absorption at rest into deuteron and {sup 4}He are also calculated.
The University of Texas M.D. Anderson Cancer Center Proton Therapy Facility
International Nuclear Information System (INIS)
Smith, Alfred; Newhauser, Wayne; Latinkic, Mitchell; Hay, Amy; Cox, James; McMaken, Bruce; Styles, John
2003-01-01
The University of Texas M.D. Anderson Cancer Center (MDACC), in partnership with Sanders Morris Harris Inc., a Texas-based investment banking firm, and The Styles Company, a developer and manager of hospitals and healthcare facilities, is building a proton therapy facility near the MDACC main complex at the Texas Medical Center in Houston, Texas USA. The MDACC Proton Therapy Center will be a freestanding, investor-owned radiation oncology center offering state-of-the-art proton beam therapy. The facility will have four treatment rooms: three rooms will have rotating, isocentric gantries and the fourth treatment room will have capabilities for both large and small field (e.g. ocular melanoma) treatments using horizontal beam lines. There will be an additional horizontal beam room dedicated to physics research and development, radiation biology research, and outside users who wish to conduct experiments using proton beams. The first two gantries will each be initially equipped with a passive scattering nozzle while the third gantry will have a magnetically swept pencil beam scanning nozzle. The latter will include enhancements to the treatment control system that will allow for the delivery of proton intensity modulation treatments. The proton accelerator will be a 250 MeV zero-gradient synchrotron with a slow extraction system. The facility is expected to open for patient treatments in the autumn of 2005. It is anticipated that 675 patients will be treated during the first full year of operation, while full capacity, reached in the fifth year of operation, will be approximately 3,400 patients per year. Treatments will be given up to 2-shifts per day and 6 days per week
Light tetraquarks and mesons in a DSE/BSE approach
Energy Technology Data Exchange (ETDEWEB)
Heupel, Walter
2015-07-01
are of a dynamical nature and are not put in by hand. Additionally, these two-body poles in the four-body equation can be interpreted as connection between the more fundamental four-body picture, where four quarks bind together, and the two-body picture, where the tetraquark is pictured as a bound state of two mesons and/or diquarks. In accordance with previous studies in a two-body framework, the pion-pion correlations are found to be much more dominant than the diquark-diquark correlations. Guided by the result that the tetraquark is dominated by poles in the phase space, an explicit pole ansatz for the amplitude was constructed, improving the numerical stability considerably. Subsequently, the Bethe-Salpeter equation was solved for tetraquarks with the quantum numbers 0++. For physical u/d-quark masses, the masses of the σ(0.35 GeV), κ(0.64 GeV) and the f{sub 0}/a{sub 0}(0.89 GeV) were calculated, with the corresponding masses given in brackets. Compared with the values of the experimental candidates, the masses are generically too low, probably caused by truncation artifacts. Nonetheless, according to the success of the Maris-Tandy model to describe ground state properties of mesons and baryons, the result is a strong indication that the lowest scalar nonet has indeed a considerable tetraquark component. Investigating the quark mass dependence of the sigma, candidates for an all strange tetraquark around 1.6 GeV and an all charm tetraquark around 5.7 GeV were found. These findings agree qualitatively with former results from a two-body approach. Additionally, the mass curve features an interesting cusp at a quark mass of about 0.65 GeV. Such cusps are known in the literature to be related to whether the T-matrix pole corresponds to a bound-state, a resonance or a virtual state. Part II: Following the time-honored concept of taking functional derivatives to obtain an interaction kernel, this technique is extended to vertex models which explicitly depend on the
Typical-medium multiple-scattering theory for disordered systems with Anderson localization
Terletska, H.; Zhang, Y.; Chioncel, L.; Vollhardt, D.; Jarrell, M.
2017-04-01
The typical medium dynamical cluster approximation (TMDCA) is reformulated in the language of multiple scattering theory to make possible first-principles calculations of the electronic structure of substitutionally disordered alloys including the effect of Anderson localization. The TMDCA allows for a systematic inclusion of nonlocal multisite correlations and at the same time provides an order parameter, the typical density of states, for the Anderson localization transition. The relation between the dynamical cluster approximation and the multiple scattering theory is analyzed, and is illustrated for a tight-binding model.
Lopez, Matthias; Clément, Jean-François; Lemarié, Gabriel; Delande, Dominique; Szriftgiser, Pascal; Garreau, Jean Claude
2013-06-01
We realize experimentally a cold-atom system, the quasiperiodic kicked rotor, equivalent to the three-dimensional Anderson model of disordered solids where the anisotropy between the x direction and the y-z plane can be controlled by adjusting an experimentally accessible parameter. This allows us to study experimentally the disorder versus anisotropy phase diagram of the Anderson metal-insulator transition. Numerical and experimental data compare very well with each other and a theoretical analysis based on the self-consistent theory of localization correctly describes the observed behavior, illustrating the flexibility of cold-atom experiments for the study of transport phenomena in complex quantum systems.
Penguin effects induced by the two-Higgs-doublet model and charmless B-meson decays
International Nuclear Information System (INIS)
Davies, A.J.; Joshi, G.C.; Matsuda, M.
1991-01-01
Nonstandard physical effects through the penguin diagram induced by the charged Higgs scalar contribution in the two-Higgs-doublet model are analysed. Since non-leptonic B-decay processes to final states consisting of s+s+anti s are induced only through the penguin diagram they are important tests of such contributions. We compare these decays including the non-standard two-Higgs-doublet contribution with the standard model results, which arise from the magnetic gluon transistion term. The charged Higgs contribution can give a sizable enhancement to the branching fraction of B-meson charmless decay. (orig.)
Anomalous triple gauge couplings from $B$-meson and kaon observables
Bobeth, Christoph
2015-01-01
We consider the three CP-conserving dimension-6 operators that encode the leading new-physics effects in the triple gauge couplings. The contributions to the standard-model electromagnetic dipole and semi-leptonic vector and axial-vector interactions that arise from the insertions of these operators are calculated. We show that radiative and rare $B$-meson decays provide, under certain assumptions, constraints on two out of the three anomalous couplings that are competitive with the restrictions obtained from LEP II, Tevatron and LHC data. The constraints arising from the $Z \\to b \\bar b$ electroweak pseudo observables, $K \\to \\pi \
The Crystal Barrel: Meson Spectroscopy at LEAR with a 4$\\pi$ Detector
2002-01-01
% PS197 \\\\ \\\\The Crystal Barrel is a 4$\\pi$ spectrometer designed to provide complete and precise information on practically every final state produced in $\\bar{p} p $ and $\\bar{p}d $ annihilations at low energy and to collect high statistics data samples. Selective triggers can be applied when necessary. \\\\ \\\\The physics goal is to identify all light mesons in the mass range from 0.14 to 2.3~GeV/c$^{2}$, to determine their quantum numbers and decay properties and to study the annihilation dynamics. The main interest is to find the glueball and hybrid degrees of freedom predicted in the framework of Quantum Chromodynamics. \\\\ \\\\\
A calculation of the physical mass of sigma meson
Indian Academy of Sciences (India)
Author Affiliations. J R Morones-Ibarra1 Ayax Santos-Guevara1. Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma, de Nuevo León, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, 66450, México ...
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
Charged current couplings and the physics of B mesons
International Nuclear Information System (INIS)
Paschos, E.A.; Tuerke, U.
1984-01-01
We give precise values for the elements of the flavor mixing matrix and the CP-violating phase, then study their dependence on the unknown dynamical parameters, like the bag factor, QCD corrections, mass of the top quark;... We estimate the mixing properties of the Bsub(d) and Bsub(s) states and discuss CP-violating effects, especially for the Bsub(s) states. (orig.)
Charm physics: theoretical review
International Nuclear Information System (INIS)
Petrov, Alexey A.
2003-01-01
Charm physics plays a unique dual role in the modern investigation of flavor physics. Charm decay and production experiments provide valuable checks and supporting measurements for studies of CP-violation in measurements of CKM parameters in b-physics, as well as outstanding opportunities for searches for new physics. Historically, many methods of heavy quark physics have been first tested in charmed hadrons. The fact that a b-quark mainly decays into a charm quark makes charm physics an integral part of any b-physics program. In many cases direct measurements of charm decay parameters directly affect the studies of fundamental physics in B decays. This year brought several interesting developments in some seemingly well-understood sectors of charm physics, such as meson spectroscopy. We review recent developments in charm physics, focusing on the physics of charmed mesons. We discuss charm spectroscopy, decay constants and transition form factors, as well as searches for new physics with charmed mesons. We discuss D 0 D 0 -bar mixing and CP-violation in charm decays. (author)
On Decays of B Mesons to a Strange Meson and an Eta or Eta' Meson at Babar
Energy Technology Data Exchange (ETDEWEB)
Hirschauer, James Francis [Univ. of Colorado, Boulder, CO (United States)
2009-01-01
We describe studies of the decays of B mesons to final states ηK*(892), ηK*_{0}(S-wave), ηK*_{2}(1430), and η'K based on data collected with the BABAR detector at the PEP-II asymmetric-energy e^{+}e^{-} collier at the Stanford Linear Accelerator Center. We measure branching fractions and charge asymmetries for the decays B → ηK*, where K* indicates a spin 0, 1, or 2 Kπ system, making first observations of decays to final states ηK^{0*}_{0}(S-wave), ηK^{+*}_{0} (S-wave), and ηK^{0*}_{2}(1430). We measure the time-dependent CP-violation parameters S and C for the decays B^{0} → η'K^{0}, observing CP violation in a charmless B decay with 5σ significance considering both statistical and systematic uncertainties.
High-energy behavior of fermion-meson and meson-meson scattering in a supersymmetric field theory
International Nuclear Information System (INIS)
Opoien, J.W.
1978-01-01
The high-energy behavior of fermion-boson and boson-boson scattering amplitudes of a supersymmetric field theory containing a spin-1/2 fermion field, a scalar field, and a pseudoscalar field is investigated. The results can be easily modified to apply to the Yukawa model and the neutral version of the linear sigma model. The results are also compared to those of fermion-fermion scattering in the same model. In the leading-logarithm approximation, ladders with fermions running along the sides in the t channel and mesons as rungs dominate in each order of two classes of diagrams. The sum of the dominant series give rise to fixed Regge cuts for all amplitudes in each of the three theories. All amplitudes in the supersymmetric theory possess a definite signature factor, while the amplitudes for fermion-fermion and fermion-antifermion scattering in the Y model and the sigma model lack it. The results of the supersymmetric theory are also compared to the results of the spontaneously broken non-Abelian gauge theory
Measurement of the semileptonic charge asymmetry in B.sup.0./sup. meson mixing with the D0 detector
Czech Academy of Sciences Publication Activity Database
Abazov, V. M.; Abbott, B.; Acharya, B.S.; Kupčo, Alexander; Lokajíček, Miloš
2012-01-01
Roč. 86, č. 7 (2012), "072009-1"-"072009-21" ISSN 1550-7998 R&D Projects: GA MŠk LA08047; GA MŠk(CZ) LG12006 Institutional research plan: CEZ:AV0Z10100502 Keywords : D0 * detector * asymmetry * mesons Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.691, year: 2012 http://link.aps.org/doi/10.1103/PhysRevD.86.072009
Energy Technology Data Exchange (ETDEWEB)
De Cecco, Sandro [Univ. of Rome (Italy)
2003-01-01
The analysis presented in this thesis are first strong evidences for both the new CDF Secondary Vertex Trigger ability in the on-line selection of heavy flavour hadronic decays in $p\\bar{p}$ interactions and for the $CDF$ potentials, in particular on charm physics. The result of the relative BR measurements for $D^0$ mesons two-body decays presented in this thesis is at this time competitive with best single measurement obtained by the CLEO experiment. Analysis and reconstruction tools developed for charm mesons are tuned and validated at a very refined level and constitute the framework for B mesons analysis in hadronic final states like $B_{s} → D_{s}\\pi$. As prospected in final sections, competitive measurements and limits on $D^0$ mixing and direct CP violation in $D^0$ mesons decays will be possible with the luminosity integrated in the future of $CDF$ operations. Also, studies on particle ID with $dE/dx$ and CDF Time-of-Flight, are presented and their validat ion on high statistic sample of charmed mesons will allow a precise knowledge of $CDF$ PID global performance. This will be of particular relevance for flavour tagging techniques and especially those based on Kaon tagging will benefit of this study. This point will be crucial, as underlined in final section for $B_s$ oscillation mixing frequency measurement at $CDF$.
Elliptic flow of .eta. and ă.sub.o mesons in heavy-ion collisions at 2 A GeV
Czech Academy of Sciences Publication Activity Database
Taranenko, Arkadij; Kugler, Andrej; Marín, A.; Díaz, J.; Averbeck, R.; Doppenschmidt, A.; Hlaváč, S.; Holzmann, R.; Lefévre, F.; Schubert, A.; Simon, R. S.; Charbonnier, Y.; Martínez, G.; Schutz, Y.; Marqués, F. M.; Appenheimer, H.; Berg, F. D.; Metag, V.; Novotny, R.; Stroher, H.; Weiss, J.; Wolf, A. R.; Wolf, H.; Löhner, H.; Ostendorf, R. W.; Vogt, P.; Wilschut, H. W.; Baiborodin, Dmitri; Pleskač, Radek; Tlustý, Pavel; Wagner, Vladimír
2000-01-01
Roč. 50, - (2000), s. 139-166 ISSN 0011-4626. [TAPS Workshop /5./ "Electromagnetic and Mesonic Probes of Nuclear Matter". Prague, 04.09.1999-08.09.1999] Institutional research plan: CEZ:AV0Z1048901 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.298, year: 2000
Elliptic flow of Eta and ă.sup.o./sup. mesons in heavy-ion collisions at 2 A GeV
Czech Academy of Sciences Publication Activity Database
Taranenko, Arkadij; Kugler, Andrej
2000-01-01
Roč. 50, č. 54 (2000), s. 139-140 ISSN 0011-4626 R&D Projects: GA ČR GA202/00/1668 Keywords : relativistic heavy ion collisions * Eta and Pion mesons * elliptic flow Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.298, year: 2000
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.
International Nuclear Information System (INIS)
Wissel, S.
2006-10-01
In this thesis we investigate thermal in-medium modifications of various mesonic correlation functions by lattice simulations of Quantum Chromodynamics for light valence quark masses and vanishing chemical potential. Mesonic properties are typically extracted from spatial correlation functions. The results presented are based on quenched gauge field configurations generated with the standard Wilson plaquette gauge action. Concerning the fermionic part of the action, we use the non-perturbative O(a) improved Sheikholeslami-Wohlert as well as the truncated hypercube perfect action. Furthermore we utilize the maximum entropy method in order to determine physically relevant pole masses and to investigate thermal modifications of physical states and possible lattice artefacts in the interacting case. The analyses of pole and screening masses, dispersion relations, wave functions, decay constants and spectral functions essentially yield no significant modifications of the zero-temperature behavior up to 0.55 T c . Close to the phase transition in-medium effects seem to appear, which lead inter alia to significant differences between pole and screening masses. The decay constants are in good agreement with the experimental values. We have simulated above T c at nearly zero quark masses. At 1.24 T c , the occurrence of topological effects, a sign for the presence of a still broken U(1) A symmetry, prevent a more thorough analyses close to the phase transition. A complete continuum and infinite volume extrapolation of screening masses, guided by free lattice effective masses is done. It shows that the presence of collective phenomena at 1.5 and 3 T c cannot be explained by pure lattice artefacts. Unlike the vector meson the pion is far from being considered an unbound state. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Wissel, S.
2006-10-15
In this thesis we investigate thermal in-medium modifications of various mesonic correlation functions by lattice simulations of Quantum Chromodynamics for light valence quark masses and vanishing chemical potential. Mesonic properties are typically extracted from spatial correlation functions. The results presented are based on quenched gauge field configurations generated with the standard Wilson plaquette gauge action. Concerning the fermionic part of the action, we use the non-perturbative O(a) improved Sheikholeslami-Wohlert as well as the truncated hypercube perfect action. Furthermore we utilize the maximum entropy method in order to determine physically relevant pole masses and to investigate thermal modifications of physical states and possible lattice artefacts in the interacting case. The analyses of pole and screening masses, dispersion relations, wave functions, decay constants and spectral functions essentially yield no significant modifications of the zero-temperature behavior up to 0.55 T{sub c}. Close to the phase transition in-medium effects seem to appear, which lead inter alia to significant differences between pole and screening masses. The decay constants are in good agreement with the experimental values. We have simulated above T{sub c} at nearly zero quark masses. At 1.24 T{sub c}, the occurrence of topological effects, a sign for the presence of a still broken U(1){sub A} symmetry, prevent a more thorough analyses close to the phase transition. A complete continuum and infinite volume extrapolation of screening masses, guided by free lattice effective masses is done. It shows that the presence of collective phenomena at 1.5 and 3 T{sub c} cannot be explained by pure lattice artefacts. Unlike the vector meson the pion is far from being considered an unbound state. (orig.)
Decays of mesons containing heavy quarks
International Nuclear Information System (INIS)
Jagannathan, K.
1980-01-01
We find that the spectator model fails to describe the non-leptonic decays satisfactorily because the hadronization of the two quark-antiquark pairs in the final state is not treated properly. A final state q anti q pair, in this model, can be in both color-singlet and color-octet states; however a color-octet q anti q state cannot evolve into ordinary (color-singlet) hadrons without exchanging color with the other color-octet q anti q pair. Such interactions are ignored in the usual treatment. We propose an alternative model - called the color singlet model - where we consider the final state to be made up of jets of only color-singlet (q anti q) states, and the interactions leading to this configuration are described by an effective Hamiltonian. In our model, any final state of the type anti q 1 q 2 anti q 3 q 4 will form two different color-singlet jet configurations vis. (anti q 1 q 2 )(anti q 3 q 4 )(anti q 1 q 4 )(anti q 3 q 2 ). We show that these considerations lead naturally to a difference in the lifetimes of the D 0 and D - mesons. An alternative model discussed in the literature for explaining the difference in D 0 and D + lifetimes is also outlined and a critical account of the differences in the predictions of the two models is presented
Determination of the D mesons lifetimes
International Nuclear Information System (INIS)
Josa Mutuberria, M.I.
1990-01-01
The results from the experiment NA27, performed in the North Area of the Super Proton Synchrotron at CERN are presented. The experimental set up was the small, high resolution, rapid cyling bubble chamber LEBC coupled with the European Hybrid Spectrometer (EHS). More than 2 millions pictures were taken, with 1015000 in teractions in hydrogen. The stastistical sensitivity of the experiment was 38.5 events/μb. A clean sample of 700 charm particle decays was obtained. Estimators with minimal systematic and statistical errors are developed for the determination of the lifetimes of short-lived particles whose individual momenta are unknown. These estimators make use of the measured decay lengths and the a priori known production characteristics. In this way, it is possible to include identified but not fully reconstructed charm decays in the sample to determine their lifetime. The properties of these estimators were extensively studied by means of Montecarlo simulation. The detection of the short-lived particles through the impact parameter of their charged decay products leads to additional complications which are taken into account. The biases and statistical errors inherent in using simpler approximate lifetime estimators are also discussed. These estimators are applied to determine the lifetime of the D o and D +- mesons using the charm data sample from NA27. (Author)
Nonequilibrium quantum meson gas: Dimensional reduction
Alvarez-Estrada, R. F.
2009-07-01
A nonequilibrium quantum gas of interacting relativistic effective mesons, ressembling qualitatively those produced in a heavy-ion collision, is described by a scalar φ^{{4}}_{} quantum field in (1 + 3) -dimensional Minkowski space. For high temperature and large temporal and spatial scales, we justify that classical statistical mechanics including quantum renormalization effects describe approximately the gas: nonequilibrium dimensional reduction (NEDR). As a source of hints, we treat the gas at equilibrium in real-time formalism and obtain simplifications for high temperature and large spatial scales, thereby extending a useful equilibrium dimensional reduction known for the imaginary-time formalism. By assumption, the nonequilibrium initial state of the gas, not far from thermal equilibrium, includes interactions and inhomogeneities. We use nonequilibrium real-time generating functionals and correlators at nonzero temperature. In the NEDR regime, our arguments yield: 1) renormalized correlators simplify, 2) the perturbative series for those simplified correlators can be resummed into a new nonequilibrium generating functional, Z’ r, dr , which is super-renormalizable and includes renormalization effects (large position-dependent thermal self-energies and effective couplings). Z’ r, dr could enable to study nonperturbatively changes in the phase structures of the field, by proceeding from the nonequilibrium quantum regime to the NEDR one.
Electromagnetic Studies of Mesons, Nucleons, and Nuclei
Energy Technology Data Exchange (ETDEWEB)
Baker, Oliver K.
2013-08-20
Professor Baker was a faculty member at Hampton University in Hampton, Virginia, and, jointly, a Staff Physicist at Jefferson Lab in nearby Newport News from September 1989 to July 2006. The Department of Energy (DOE) funded the grant DE-FG02-97ER41035 Electromagnetic Studies of Mesons, Nucleons, and Nuclei, while Baker was in this joint appointment. Baker sent a closeout report on these activities to Hampton University’s Sponsored Research Office some years ago, shortly after joining Yale University in 2006. In the period around 2001, the research grant with Baker as the Principal Investigator (PI) was put under the supervision of Professor Liguang Tang at Hampton University. Baker continued to pursue the research while in this join appointment, however the administrative responsibilities with the DOE and with Hampton University rested with Professor Tang after 2001, to my recollection. What is written in this document is from Baker’s memory of the research activities, which he has not pursued since joining the Yale University faculty.
New results on mesons containing strange quarks
Energy Technology Data Exchange (ETDEWEB)
Aston, D.; Awaji, N.; Bienz, T.; Bird, F.; D' Amore, J.; Dunwoodie, W.; Endorf, R.; Fujii, K.; Hayashii, H.; Iwata, S.
1987-01-01
Recent results of strange and strangeonium mesons are presented. The data come from a high sensitivity study (4.1 ev/nb) of K/sup -/p interactions at 11 GeV/c using the LASS spectrometer at SLAC. The complete leading orbitally-excited K* series up through J/sup P/ = 5/sup -/ and a substantial number of the expected underlying states are observed decaying into K/sup -/..pi../sup +/, anti K/sub 3//sup 0/..pi../sup +/..pi../sup -/, and K eta final states, and new measurements are made of their masses, widths, and branching ratios. Production of strangeonium states via hypercharge exchange is observed into K/sub 3//sup 0/K/sub 3//sup 0/, K/sup -/K/sup +/, and K/sub 3//sup 0/K/sup + -/..pi../sup - +/ final states. The leading orbitally-excited phi series through J/sup P/ = 3/sup -/ is clearly seen and evidence is presented for additional high spin structure in the 2.2 GeV/c/sup 2/ region. No f/sub 2/(1720) is observed. The K/sub 3//sup 0/K/sup + -/..pi../sup - +/ spectrum is dominated by 1/sup +/(K* anti K + anti K* K) production in the region below 1.6 GeV/c/sup 2/. These results are compared with data on the same systems produced by different production mechanisms. 12 refs., 28 figs.