Sample records for baryonium

  1. Baryoniums and related states

    International Nuclear Information System (INIS)

    Hong-Mo, C.


    A brief introduction is given to current theoretical ideas on baryonium states with particular emphasis on their interpretation as 'colour molecules'. It is argued that baryonium spectroscopy provides a valuable test for colour as a new degree of freedom. (author)

  2. Baryoniums - the S-matrix approach

    International Nuclear Information System (INIS)

    Roy, D.P.


    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. Baryonium exchange in inclusive neutron production

    International Nuclear Information System (INIS)

    Paciello, M.L.; Taglienti, B.; Petrarca, S.


    A triple-Regge analysis of pp→n + anything and pn→p + anything is performed in terms of the conventional π trajectory and an exotic G = -P = + trajectory (baryonium). A substantial improvement with respect to previous fits is obtained; the exotic trajectory turns out to have a large coupling with the Pomeron and then it badly violates the OZI rule for junction lines. (author)

  4. Baryonium states: Where do they begin

    Energy Technology Data Exchange (ETDEWEB)

    Mitra, A.N.


    An investigation of the mass levels of ground and excited qqq-barq-bar (baryonium) states is carried out within a Bethe--Salpeter framework for a four-body system with pairwise q-q-bar and q-q interactions of the h.o. type. The identity of quarks, and separately, of antiquarks, in a qqq-barq-bar system gives rise to a well-defined set of selection rules governing the spin-isospin-orbital structures of T- and M-baryonia. A relativistic mass formula, similar to those derived recently for qq-bar and qqq systems, including spin and momentum dependent effects, is now obtained for the qqq-barq-bar system. The values of the parameters employed for mass prediction for qqq-barq-bar states, viz., the non-strange quark mass (m/sub q/ = 0.28) and the reduced spring constant (omega-bar = 0.15), are the same as those used earlier for a successful description of non-strange qq-bar and qqq spectroscopy in a unified fashion. The main prediction on the mass locations is that the orbitally unexcited qqq-barq-bar states are all in the range 2.5--3.1 GeV, the lowest one (a scalar T-baryonium) being around 2.5 GeV. Possible experimental significance of this result is briefly discussed in the latest context of disappearance of the sharp features of most baryonium states.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hua-Xing; Zhou, Dan [Beihang University, School of Physics, Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beijing (China); Chen, Wei [University of Saskatchewan, Department of Physics and Engineering Physics, Saskatoon, SK (Canada); Liu, Xiang [Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Lanzhou University, Research Center for Hadron and CSR Physics, Institute of Modern Physics of CAS, Lanzhou (China); Zhu, Shi-Lin [Peking University, School of Physics, State Key Laboratory of Nuclear Physics and Technology, Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Peking University, Center of High Energy Physics, Beijing (China)


    We give an explicit QCD sum rule investigation for hidden-charm baryonium states with the quark content u anti ud anti dc anti 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, which can actually couple to various structures, including hidden-charm baryonium states, charmonium states plus two pions, and hidden-charm tetraquark states plus one pion, etc. We do not know which structure these currents couple to at the beginning, but after sum rule analyses we can obtain some information. We find some of them can couple to hidden-charm baryonium states, using which we evaluate the masses of the lowest-lying hidden-charm baryonium states with quantum numbers J{sup P} = 2{sup -}/3{sup -}/0{sup +}/1{sup +}/2{sup +} to be around 5.0 GeV. We suggest to search for hidden-charm baryonium states, especially the one of J = 3{sup -}, in the D-wave J/ψππ and P-wave J/ψρ and J/ψω channels in this energy region. (orig.)

  6. From baryonium to hexons

    International Nuclear Information System (INIS)

    Nicolescu, B.; Poenaru, V.


    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

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

    International Nuclear Information System (INIS)

    Chan Hong-Mo.


    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)

  8. Twisted-baryon-loop effects in dual topological unitarization

    Energy Technology Data Exchange (ETDEWEB)

    Gauron, P.; Nicolescu, B.; Ouvry, S.; Uschersohn, J.


    Within the framework of dual topological unitarization we propose a simple model for mesons, baryons, and baryonium which allows us to calculate the effects of inserting nonplanar BB-bar loops in all possible ways into meson and baryonium propagators. We study the renormalization of the leading nonzero-isospin trajectories and the mixing of qq-bar and qqq-barq-bar states.

  9. Current status on narrow N anti N states

    International Nuclear Information System (INIS)

    Chung, S.U.


    An attempt is made to summarize the experimental status of narrow B anti B states as of mid-1979. In particular, concentration is placed on the current experimental situations and prospects regarding three serious contenders for the so-called baryonium states. Theoretical concepts of baryoniums, narrow N anti N states known as S(1935), anti pp(2020), and anti pp(2204), and some forthcoming results, and problems of the above three resonances are discussed. 31 references

  10. New directions in elementary particle physics: p anti p from very low to very high energies

    International Nuclear Information System (INIS)

    Jacob, M.


    The review covers low energy anti pp physics including annihilation processes, the spectroscopy of baryonium states, quasinuclear states and their relation to baryonium, the spectroscopy of protonium, and access to the whole charmonium family. High energy anti pp physics is reviewed covering total cross section rise, the common shape of cross sections, real part of forward amplitude, particle production, quantum number excitation, high transverse momentum, and high mass lepton pair. Also reviewed are the search for the weak bosons, hadron physics at collider energies, and the anti pp collider program. 47 references

  11. Study of the reactions π+p→Δ++p anti p at 20 GeV/c

    International Nuclear Information System (INIS)

    Triscos, P.


    A search for backwards produced mesons decaying into p anti p system (baryonium) through the reaction π + p→Δ ++ pantip was the main purpose of WA 56 experiment (C.E.R.N. - Omega spectrometer). After a theoretical and experimental review on baryonium states, we describe the lay out of the apparatus. In the analysis we underline the possibility to identify slow particules by means of a scintillator counter surrounding the target. First results are reported; no significant structure has been observed in pantip invariant mass distribution [fr

  12. NantiN forces and annihilation in the potential approach

    International Nuclear Information System (INIS)

    Vinh Mau, R.


    The future experimental program of LEAR justifies the necessity for a careful theoretical study of the nucleon-antinucleon interaction. The question is whether the baryonium states exist and if so, whether they can the described as NantiN bound states or resonances

  13. 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

  14. SHORT COMMUNICATIONA Cubic Power Potential Model for ...

    African Journals Online (AJOL)

    SHORT COMMUNICATIONA Cubic Power Potential Model for Baryonium. L. K. Sharma. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for ...

  15. Annual report 1979-1980

    International Nuclear Information System (INIS)

    Experiments have been performed at CERN in collaboration with scientists from other laboratories: search of new narrow resonant structures, baryonium, dibaryons, hadrons structure studied with the 'Lezard' spectrometer, flavour... The participation to the UA1 experiment continued and developed a very important technical cooperation [fr

  16. A four-body potential in multiquark states

    International Nuclear Information System (INIS)

    Warner, R.C.; Joshi, G.C.


    A detailed analysis is presented of the first member of a previously derived hierarchy of instanton generated many-body potentials for multiquark states. Comparison with two-body instanton generated potential in the heavy quark framework is made in the T-baryonium system

  17. GeV partons and TeV hexons from a topological viewpoint

    International Nuclear Information System (INIS)

    Chew, G.F.; Issler, D.; Nicolescu, B.; Poenaru, V.


    An elementary TeV topological hadron supermultiplet breaks into GeV-scale mesons, baryons and baryoniums and TeV-scale ''hexons'' (extremely-heavy bosons corresponding to six topological constituents). Phenomena on the GeV scale are described by parton graphs which give meaning to constituent quarks of QCD type. Hexons are responsible -through mixing- for electroweak-bosons masses, may be responsible for cosmic-ray Centauro events, and promise novel TeV accelerator phenomena

  18. Elementary particle physics. Progress report covering the five year period November 1, 1974 to October 31, 1979. [Summaries of research activities at Florida State Univ

    Energy Technology Data Exchange (ETDEWEB)


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

  19. Why explicit gluonic components are needed in multiquark wave functions

    International Nuclear Information System (INIS)

    Lipkin, H.J.


    Constituent quark models with nontrivial correlations between color and space and no explicit description of the gluon degrees of freedom are inconsistent with local color gauge invariance. The screening by gluons of local color density in the quark sector must be included in treatments of long range forces in multiquark states. Neglect of gauge invariance and screening leads to erroneous predictions like unobserved Van der Weals forces and unobserved ''baryonium'' states with localized color. (author)

  20. Note on the narrow 3.1 GeV (Λ p-bar + pions)

    International Nuclear Information System (INIS)

    Chan Hongmo; Tsou Sheungtsun


    It is pointed out that the narrow exotic U(3.105) (Λ p-bar + pions) state reported at CERN and Serpukhov and its companion at 3.410 GeV, fall neatly on top of the spectrum predicted nine years ago for 'M-baryoniums' and agree with the expected decay characteristics. Further, when so interpreted, their spacing gives a direct measure of the colour Casimir factor in the string tension. (author)

  1. The colour and flavour 1/N expansions

    International Nuclear Information System (INIS)

    Veneziano, G.

    General ideas about the colour and flavour 1/N expansions are presented in a non-specialized fashion according to both: a unified approach to meson dynamics (the basic logical scheme, lepton-hadron interactions, hadronic processes in lowest order, higher order effects and the Reggeon calculus); and a possible extension to baryons (difficulties with baryons in dual and gauge theories, possible definition of dual baryons in quantum chromodynamics, lowest order B anti-B and BB scattering: baryonium, Reggeon calculus for processes involving baryons)

  2. On the production of narrow q2antiq2

    International Nuclear Information System (INIS)

    Hoffman, H.J.


    A rather detailed prediction of the mass spectrum and decay modes of Baryonium (or alternatively - diquonium) states has been proposed. The Baryonium in this approach is pictured as a diquark and an antidiquark bound by a short range force but separated by high angular momentum (L approximately or >1). Color plays a crucial role in the procedure, leading to the emergence of two distinct types of qq anti q anti q resonances. One kind has the qq (anti q anti q) pair in colour anti 3 (3) representation and hence consists of broad states decaying primarily into anti B B (T(True)-diquonium). The other type arises when the relevant color representation is 6(anti 6) which means that decay into anti B B must be suppressed if color is to be confined (M(Mock)-diquonium). Both qq anti q anti q classes are expected to decay only reluctantly into mesons as a result of the angular momentum barrier, an argument which derives its main support from the Dual Unitarisation scheme. Experimentally, this means that M-diquoniums should be rather easily detectable objects as they are distinguished by their narrowness on the one hand and their cascade decay mode on the other. The primary aim here is to elaborate on the production mechanisms for the various trajectories, using these to get some estimates of the cross-sections involved. (author)

  3. 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.

  4. Session A5: hadron spectroscopy, experimental

    International Nuclear Information System (INIS)

    Ozaki, S.


    Reports 55 contubutions made by mini-rapporteurs and individual contributors are assembled. It is clear, from the contributions made to this session, that there has been steady progress in solving the problem of the hadron spectroscopy of the old style. The picture on the scalar mesons has become clearer. Among the vector meson group, we started to understand Q mesons, though the situation with A 1 is still not clear. Mesons with higher spin have been found and, in some cases, confirmed. In a sense, the jigsaw puzzle on the mesons is gradually being completed while more complex features are found. The same can be said on the baryons. An active study is in progress in the experiment on the exotic states such as narrow baryonium and dibaryon states. However, owing to the difficulty of such experiments and interpretation of the data, a definitive result is yet to come. 94 references

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

    International Nuclear Information System (INIS)

    Kirsch, L.E.; Schnitzer, H.J.; Abbott, L.F.; Bensinger, J.R.; Blocker, C.A.


    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

  6. The quark bag model

    International Nuclear Information System (INIS)

    Hasenfratz, P.; Kuti, J.


    The quark bag model is reviewed here with particular emphasis on spectroscopic applications and the discussion of exotic objects as baryonium, gluonium, and the quark phase of matter. The physical vacuum is pictured in the model as a two-phase medium. In normal phase of the vacuum, outside hadrons, the propagation of quark and gluon fields is forbidden. When small bubbles in a second phase are created in the medium of the normal phase with a characteristic size of one fermi, the hadron constituent fields may propagate inside the bubbles in normal manner. The bubble (bag) is stabilized against the pressure of the confined hadron constituent fields by vacuum pressure and surface tension. Inside the bag the colored quarks and gluons are governed by the equations of quantum chromodynamics. (Auth.)

  7. Duality, exchange-degeneracy breaking, and exotic states

    International Nuclear Information System (INIS)

    Goldstein, G.R.; Haridas, P.


    We study the connection between exchange-degeneracy breaking and multiquark states within the framework of a highly constrained dual approach. We show that M 4 (baryonium) states emerge at the daughter trajectory level as a consequence of small exchange-degeneracy breaking in the meson-meson system ( and larger exchange-degeneracy breaking of the baryon trajectories in the meson-baryon system (approx.epsilon). The M 4 states are coupled weakly to external mesons in proportion to the breaking parameter delta. Assuming M 4 couplings to B-barB channels are strong, as determined by duality with normal mesons in the B-barB system, consistency requires epsilon approx. √delta-bar, thereby relating the larger breaking of baryon trajectories to the violation of the Okubo-Zweig-Iizuka-type rule for M 4 . It is shown that exotic baryon states, B 5 , also emerge from this scheme at the daughter level and that dibaryons will appear at the second daughter level

  8. Summary of the most significant results reported in this session

    CERN Document Server

    Van De Walle, R T


    In the following a summary is presented of five parallel sessions on light quark had- ron spectroscopy. In general all topics which were discussed in the plenary sessions, and for which the proceedings contain separate (invited) papers, will be left out; only occa- sionally (and for reasons of completeness) will we make a reference to these presentations. Several other restrictions can be made. Nearly all papers submitted to the (parallel) hadron spectroscopy sessions were experimenta1 1 ), the only exceptions being a series of four theoretical papers on the baryonium problem. Furthermore, there was virtually no new information concerning the 'classical' baryons. In particular, no new facts were submitted on the problem of the possible existence of baryon states outside the so-called minimal spectrum, i.e. outside {56,L+ } and {70,L-dd}, the existence of the {ZO}'s, and the exis- even o tence of (baryon) exotic states. There was one contribution on a 'possible' new:".* 2 ), and a report on the final measureme...

  9. 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...

  10. 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)

    Lellouch, D.


    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/c 2 . 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/c 2 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 [fr

  11. 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