Sample records for baryonium

  1. X(1835): A Possible Baryonium

    Institute of Scientific and Technical Information of China (English)

    ZHU Shi-Lin; GAO Chong-Shou


    We point out that the large p(p) coupling of X(1835) and the suppression of the three-body strange final states strongly indicate that X(1835) may be a p(p) baryonium. We also point out that the branching ratio of X(1835) →ηππ should be bigger than that of X(1835) →η′ππ. We suggest BES search X(1835) in the ηππ channel Finally, X(1835)may be used a tetraquark generator if X(1835) is really established as a baryonium state.

  2. Baryoniums - the S-matrix approach

    International Nuclear Information System (INIS)

    In this series of lectures the question of how the baryoniums are related to charmoniums and strangoniums is discussed and it is pointed out that in the S-matrix framework, they all follow from the same pair of hypotheses, duality and no exotics. Invoking no underlying quark structure, except that inherent in the assumption of no exotics, it is shown that there are no mesons outside the singlet and octet representation of SU(3) and no baryons outside the singlet, octet and decaplet. In other words all mesons occur within the quantum number of a q-antiq system and all baryons within those of qqq. This seems to be an experimental fact, which has no natural explanation within the S-matrix framework except that it is the minimal non-zero solution to the duality constraints. The approach in the past has been to take it as an experimental input and build up a phenomenological S-matrix framework. Lately it has been realised that the answer may come from the colour dynamics of quarks. If true this would provide an important link between the fundamental but invisible field theory of quarks and gluons and the phenomenological but visible S-matrix theory overlying it. The subject is discussed under the headings; strangonium and charmonium, baryonium, spectroscopy, baryonium resonances, FESR constraint, baryonium exchange, phenomenological estimate of ω - baryonium mixing at t = 0, and models of ω - baryonium mixing. (UK)

  3. Searching for hidden-charm baryonium signals in QCD sum rules

    CERN Document Server

    Chen, Hua-Xing; Chen, Wei; Liu, Xiang; Zhu, Shi-Lin


    We give an explicit QCD sum rule investigation to hidden-charm baryonium states with the quark content $u\\bar u d\\bar d c\\bar c$, spin $J=0/1/2/3$, and of both positive and negative parities. We systematically construct the relevant local hidden-charm baryonium interpolating currents, and find that these currents can couple to various structures, including hidden-charm baryonium states, charmonium states plus two pions, and hidden-charm tetraquark states plus one pion. The masses of the lowest-lying hidden-charm baryonium states with quantum numbers $J^P=2^-/3^-/0^+/1^+/2^+$ are evaluated to be around 5.0 GeV, so we suggest to search for hidden-charm baryonium states in the $D$-wave $J/\\psi \\pi \\pi$ and $S$-wave $J/\\psi \\rho$ and $J/\\psi \\omega$ channels in this energy region.

  4. Baryonium and non-exotic hadron trajectories from a color dependent potential

    International Nuclear Information System (INIS)

    A natural explanation is presented for the apparent increase in Regge slope with number of quarks in a bound state. The framework used is that of a non-relativistic harmonic oscillator potential with a color dependence suggested by quantum chromodynamics. The ratios of modes of orbital excitations in baryonium, baryon and meson states which are in good agreement with experiment are derived, and the modes of excitation within the baryonium states discussed

  5. Search for non-strange baryonium states in the baryon exchange reaction K^{-}p to Y^{0}pp at 185 GeV/c

    CERN Document Server

    Armstrong, T; Beusch, Werner; Bloodworth, Ian J; Bonesini, M; Burns, A; Calligarich, E; Carena, F; Carney, J N; Cecchet, G; Costa, G; Dolfini, R; Ghidini, B; Kinson, J B; Knudson, K; Lenti, V; Liguori, G; Mandelli, L; Mazzanti, M; Navach, F; Palano, A; Perini, L; Pons, Y; Quercigh, Emanuele; Strachman, Z; Tamborini, M; Teodoro, D; Worsell, M F; Zito, G; Zitoun, R


    Narrow baryonium production in the baryon exchange reactions K^{-}p to Lambda pp and K^{-}p to pK^{-}pp at 18.5 GeV/c is investigated in a 12 events/nb experiment performed at the CERN Omega ' spectrometer. No narrow structure is observed in the pp mass spectra. Upper limits for production of baryonium states are given as a function of pp mass.

  6. Search for non-strange baryonium states in the baryon exchange reaction K-p → Y0overlinepp at 18.5 GeV/ c (United States)

    Armstrong, T.; Baubillier, M.; Beusch, W.; Bloodworth, I. J.; Bonesini, M.; Burns, A.; Calligarich, E.; Carena, F.; Carney, J. N.; Cecchet, G.; Costa, G.; Dolfini, R.; Ghidini, B.; Kinson, J. B.; Knudson, K.; Lenti, V.; Liguori, G.; Mandelli, L.; Mazzanti, M.; Navach, F.; Palano, A.; Perini, L.; Pons, Y.; Quercigh, E.; Strachman, Z.; Tamborini, M.; Teodoro, D.; Worsell, M. F.; Zito, G.; Zitoun, R.; Bari-Birmingham-CERN-Milan-Paris-Pavia Collaboration


    Narrow baryonium production in the baryon exchange reactions K-p → Λ overlinepp and K-p → pK-overlinepp at 18.5 GeV/ c is investigated in a 12 events/nb experiment performed at the CERN Ω' spectrometer. No narrow structure is observed in the p overlinep mass spectra. Upper limits for production of baryonium states are given as a function of p overlinep mass.

  7. From baryonium to hexons

    International Nuclear Information System (INIS)

    After a short summary of the theoretical status of fermionic and bosonic constituents of hadrons in the topological bootstrap, two distinctive predictions of this approach -narrow-width baryonia and very high-mass hexons- as well as the relevance of the diquark concept are discussed. In particular, the hexons are expected to reveal a new (TeV) scale of strong interactions

  8. New variations on two old themes - String Theory and Baryonium

    International Nuclear Information System (INIS)

    A trace factor introduced twenty years ago to incorporate internal symmetry into String Theory is generalised to include also string dynamics, while some new spectroscopic data are examined in relation to a ten year old model of exotic qq-q-barq-bar mesons. (author)

  9. Search for baryonium and the physics at FAIR

    Directory of Open Access Journals (Sweden)

    Wycech S.


    Full Text Available The existence of nucleon-antinucleon quasi-bound state is indicated in two decay modes of the J/ψ meson studied by BES. We discuss an explanation in a fairly traditional Paris-potential model of the NN̄ interactions. A broad, S-wave and a narrow P-wave quasi-bound states are predicted by this model. Some existing experimental evidence and possible verifications in the future are indicated.

  10. Twisted baryon loop effects in DTU

    International Nuclear Information System (INIS)

    Within the framwork of DTU we propose a simple model for mesons, baryons and baryonium which allows use to calculate the effects of inserting non-planar antiBB loops in all possible ways into meson and baryonium propagators. We study the renormalization of the leading non-zero isospin trajectories and the mixing of qantiq and qqantiqantiq states

  11. Research in elementary particle physics (United States)

    Kirsch, L. E.; Schnitzer, H. J.

    Research in theoretical and experimental properties of elementary particles is described. This includes measurements made at the multiparticle spectrometer facility at Brookhaven, studies of baryonium production, inclusive hyperon production, and E(0) production. Theoretical work included extended field theories, subconstituent models, finite temperature quatum chromodynamics, grad unified theories, and calculational techniques in gauge theories.

  12. Elementary particle physics. Progress report covering the five year period November 1, 1974 to October 31, 1979

    International Nuclear Information System (INIS)

    Experimental and theoretical research in high energy physics is summarized. Preparations and proposals for future experiments include high mass states decaying into phiπ+-, phiπ+-γ and phiphi produced centrally in 300 GeV/c π-p interactions, search for baryonium and for hyperonium, exotic states and charm decays, and dilepton production by neutrinos. A list of publications is included

  13. Hadron physics

    International Nuclear Information System (INIS)

    Is all hadronic physics ultimately describable by QCD. Certainly, many disparate phenomena can be understood within the QCD framework. Also certainly, there are important questions which are open, both theoretically (little guidance, as yet) and experimentally, regarding confinement. Are there dibaryons, baryonium, glueballs. In addition, there are experimental results which at present do not have an explanation. This talk, after a short section on QCD successes and difficulties, will emphasize two experimental topics which have recent results - glueball spectroscopy and exclusive reactions at large momentum transfer. Both are experimentally accessible in the AGS/LAMPF II/AGS II/TRIUMF II/SIN II energy domain

  14. Measurements of the Ratio Between Double and Single Ionization of Helium for Antiprotons

    CERN Multimedia


    The inclusive spectra of @p|0's and @h's associated with @*p annihilation at rest are measured. Peaks in these spectra can be identified either with so far not explicitly observed two mesonic final states such as @p|0@w, @p|0@h, @h@h or @p|0@g, or with production of exotic mesonlike states such as baryonium. The apparatus is also suitable for searching for baryonium through some of its particular decay channels. As a by-product we expect information on direct @g production in @*p annihilations at rest.\\\\ \\\\ The apparatus consists of two modular BGO spectrometers and one array of leadglas detectors. The BGO spectrometers are adjustable in angle relative to each other and to the leadglas matrix, thus allowing to cover an angular range from 9|0 to 180|0, corresponding to momenta of zero to more than 1~GeV/c. The apparatus is designed such as to utilize the full potential of LEAR.

  15. Stability of D brane-anti D brane systems in confining gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Ghoroku, Kazuo [Fukuoka Institute of Technology, Fukuoka (Japan); Nakamura, Akihiro [Kagoshima University, Department of Physics, Kagoshima (Japan); Toyoda, Fumihiko [Kinki University, School of Humanity-Oriented Science and Engineering, Iizuka (Japan)


    We study the stability of a special form of D brane embedding which is regarded as a bound state of D{sub n} and anti-D{sub n} brane embedded in a 10D supergravity background which is dual to a confining gauge theory. For D5 branes with U(1) flux, their bound-state configuration can be regarded as the baryonium vertex. For D branes of n=6 and 8 without the U(1) flux, their bound states have been used to introduce flavor quarks in the dual supersymmetric Yang-Mills theory. In any case, it would be important to ensure that they are free from tachyon instability. For all these cases, we could show their stability with respect to this point. (orig.)

  16. Stability of D brane-anti D brane systems in confining gauge theories (United States)

    Ghoroku, Kazuo; Nakamura, Akihiro; Toyoda, Fumihiko


    We study the stability of a special form of D brane embedding which is regarded as a bound state of D n and anti-D n brane embedded in a 10D supergravity background which is dual to a confining gauge theory. For D5 branes with U(1) flux, their bound-state configuration can be regarded as the baryonium vertex. For D branes of n=6 and 8 without the U(1) flux, their bound states have been used to introduce flavor quarks in the dual supersymmetric Yang-Mills theory. In any case, it would be important to ensure that they are free from tachyon instability. For all these cases, we could show their stability with respect to this point.

  17. Research in elementary particle physics: Technical progress report, June 1, 1986-May 31, 1987

    International Nuclear Information System (INIS)

    Work is reported in the areas of: design, construction, and testing of components of the CDF, including shower counters, electronics, and electron identification algorithms; contributions to the design and construction of the Brookhaven MultiParticle Spectrometer; search for charm and K*'s and baryonium; measurement of differential cross section and polarization in the Lambda-antiLambda channel; a study of Xi states which measured the Xi asymmetry parameter; and dibaryon searches using the Brookhaven Hypernuclear Spectrometer. Theoretical efforts are reported in the areas of string theory, the Skyrme model applied to elementary particle phenomenology, quantum field theory, cosmology, galaxy formation, supernova 187A, field theory in curved space-times, and spin-glasses

  18. Common Problems and Ideas of Modern Physics - Proceedings of the 6th Winter School on Hadronic Physics (United States)

    Bressani, T.; Minetti, B.; Zenoni, A.


    The Table of Contents for the full book PDF is as follows: * Preface * I. COHERENCE PHENOMENA * Coherence in QCD and QED * Quantum theory of scattering for tightly coupled scatterers * Gravitational radiation antenna cross sections * The EMC effect * The Mössbauer effect * II. SUBNUCLEAR PHYSICS * Heavy quarkonium spectroscopy * Baryonium phenomenology * Physics at DAΦNE * The "Darmstadt effect" * III. NUCLEAR PHYSICS * Frontiers and Perspectives in Nuclear Physics * Nuclear physics at DAΦNE * Intermediate energy antiproton-nucleus reactions to test quantum chromodynamics * Boundary condition approach to multiple scattering off composite systems * An updated survey of experimental work on nuclear cold fusion * IV. EXPERIMENTAL TECHNIQUES AND PARTICLE ACCELERATORS * The Frascati Φ-factory project * The Obelix central detector * New trends in gas drift chambers * Multi-level triggers in modem experiments * List of Participants * Subject Index * Author Index

  19. Implications of a DK Molecule at 2.32 GeV

    CERN Document Server

    Barnes, T; Lipkin, H J


    We discuss the implications of a possible quasinuclear DK bound state at 2.32 GeV. Evidence for such a state was recently reported in D_s^+pi^o by the BaBar Collaboration. We first note that a conventional quark model c-sbar assignment is implausible, and then consider other options involving multiquark systems. An I=0 c sbar n nbar baryonium assignment is one possibility. We instead favor a DK meson molecule assignment, which can account for the mass and quantum numbers of this state. The higher-mass scalar c-sbar state expected at 2.48 GeV is predicted to have a very large DK coupling, which would encourage formation of an I=0 DK molecule. Isospin mixing is expected in hadron molecules, and a dominantly I=0 DK state with some I=1 admixture could explain both the narrow total width of the 2.32 GeV state as well as the observed decay to D_s^+ pi^o. Additional measurements that can be used to test this and related scenarios are discussed.

  20. Measurement of Antiproton-proton Cross-Sections at Low Antiproton Momenta

    CERN Multimedia


    The experiment is designed to measure four different cross sections in the momentum range 150~MeV/c to 600~MeV/c: 1)~~~~the differential elastic \\\\ \\\\ 2)~~~~the differential charge exchange\\\\ \\\\ 3)~~~~the annihilation into charged and neutral pions\\\\ \\\\ 4)~~~~and the total cross section via the optical theorem. \\\\ \\\\ The experiment allows one to search once again and with good precision for baryonium. Of special interest is the existence of the S-meson, for which a signal of about 20~MeV-mb was found in a 1981 experiment (performed in the East Hall).\\\\ \\\\ A second point of special interest is the momentum region below 300~MeV/c because the cross sections are basically unknown. We will be able to explore the momentum dependence of this region for the first time.\\\\ \\\\ The elastic cross section is measured by a cylindrical multiwire proportional chamber and a scintillator hodoscope placed around a scattering chamber under vacuum. The charge exchange cross section is measured by a ring of 32~anti-neutron detector...

  1. p(-p) final state interaction in J/Ψ→γp(-p)

    Institute of Scientific and Technical Information of China (English)

    ZENG Zhuo-Quan; GUO Xin-Heng; SHEN Peng-Nian; DING Yi-Bing


    The phenomenon of the near p(-p)-threshold enhancement observed in the J/Ψ → γp(-p) decay is studied by using the enhancement factor method with a simpler one-pion-exchange potential between p and (-p).The Jost function caused by the mentioned potential is perturbatively calculated in the zero-th order approximation,and the corresponding enhancement factor is obtained.It is found that such a final state interaction offers an important contribution to the decay width near the p(-p)-threshold,although it is not large enough.To explain the decay data,a pheuomenological factor G(p) with the form of 285500/(m2/π +p2) should be introduced.A further calculation including the p-dependent bare T-matrix,a more realistic N(-N) potential and the contribution from the higher-order wave functions would provide a better understanding of the decay data and even the existence of the baryonium p(-p).The near p(-p)-threshold behavior of the decay width in the J/Ψ →π0p(-p) process is also discussed.

  2. High accuracy measurement of the total cross section and of the real part of the scattering amplitude π+p from 2 to 14 GeV/c

    International Nuclear Information System (INIS)

    This thesis presents the results of the experiment PS 157 which has been carried out at the CERN in 1980; the total cross section of π+p for 4000 values of energy was measured with an accuracy of 5%. The density of the measurements allows the exploration of a new region of the plane (width, elasticity) for narrow baryon resonances of which the mass is between 2 and 5,5 GeV/c2. The total cross section of K-p has also been measured between 4,6 and 4,9 GeV/c for 80 momentum values; the measurement quality allows to exclude any narrow resonance of which the partial elastic width is below 10 kw/c2 and to clarify the confused situation of the Δ resonances. The principles of the measurements are first given. The experimental results of the researches of narrow baryon resonances are presented; the main results of baryonium physics are recalled as also the most important theoretical models which are applied to mesobaryons. Then, one deals with the normalization process, the efficiency of the transmission detectors, and the determination of the total cross section. Finally, the total cross sections of π+p and π-p are compared, and one studies the forward elastic differential cross sections, to determinate on one side ''the slope'' of the nuclear differential cross section, and on the other side the real part of the scattering amplitude, by means of the measurement of the interference term between the Coulomb and nuclear amplitudes. 33 refs

  3. High energy physics at Tufts University. Progress report. [Summaries of research activities at Tufts University

    Energy Technology Data Exchange (ETDEWEB)


    During the year a final paper was produced on XI* production from 2.9 GeV/c K/sup -/p interactions, and a paper on the ..sigma../sup -/..pi../sup -/..pi../sup +/ (..pi../sup 0/) final state from 2.9 GeV/c K/sup -/d interactions is on the verge of completion. From our 14.75 GeV/c anti pp experiment results have been prepared for publication on three topics: the charm search, V/sup 0/ inclusive production, and ..pi../sup 0/ production. Further analysis of data is continuing. In the 300 GeV/c pp experiment, investigations are completed or underway in three areas: neutral and charged pion correlations, inclusive ..gamma.. and V/sup 0/ production, and inclusive resonance production. Further data on inclusive V/sup 0/ distributions from 6.5 GeV/c K/sup -/p interactions has been obtained and analysis is nearing completion. A good deal of effort went into the development of proposals for new physics. These new directions may be represented by three approved experiments at three different laboratories: Neutrino-deuterium interactions at Fermilab (an approved and a proposed experiment); Search for new states decaying into anti ..lambda lambda.. and K/sup 0//sub s/K/sup 0//sub s/ using the Multiparticle Spectrometer at B.N.L. (approved in May, 1977); Search for baryonium using the SLAC hybrid bubble chamber system, which won approval in September with a recommendation for prompt running from the Program Advisory Committee. A list of publications is included.

  4. Study of B Meson Decays to ppbarh Final States

    Energy Technology Data Exchange (ETDEWEB)

    Hryn' ova, Tetiana B.; /SLAC


    B mesons are unique among well-established non-quarkonium mesons in their ability to decay into baryons. Baryonic B decays offer a wide range of interesting areas of study: they can be used to test our theoretical understanding of rare decay processes involving baryons, search for direct CP violation and study low-energy QCD. This thesis presents measurements of branching fractions and a study of the decay dynamics of the charmless three-body decays of B meson into p{bar p}h final states, where h = {pi}{sup +}, K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}. With a sample of 232 million {Upsilon}(4S) {yields} B{bar B} events collected with the BaBar detector, we report the first observation of the B {yields} p{bar p}K*{sup 0} decay, and provide improved measurements of branching fractions of the other modes. The distribution of the three final-state particles is of particular interest since it provides dynamical information on the possible presence of exotic intermediate states such as the hypothetical pentaquark states {Theta}*{sup ++} and {Theta}{sup +}in the m{sub pK{sup +}} and m{sub pK{sub S}{sup 0}} spectra, respectively, or glueball states (such as the tensor glueball f{sub J}(2220)) in the m{sub p{bar p}} spectrum. No evidence for exotic states is found and upper limits on the branching fractions are set. An enhancement at low p{bar p} mass is observed in all the B {yields} p{bar p}h modes, and its shape is compared between the decay modes and with the shape of the time-like proton form factor. A Dalitz plot asymmetry in B {yields} p{bar p}K{sup +} mode suggests dominance of the penguin amplitude in this decay and disfavors the possibility that the low mass p{bar p} enhancement originates from the presence of a resonance below threshold (such as the recently seen baryonium candidate at 1835 MeV/c{sup 2}). We also identify decays of the type B {yields} X{sub c{bar c}}h {yields} p{bar p}h, where h = K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}, and X