5,080 research outputs found

    Borromean binding

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    A review is first presented of the Hall--Post inequalities relating NN-body to (N−1)(N-1)-body energies of quantum bound states. These inequalities are then applied to delimit, in the space of coupling constants, the domain of Borromean binding where a composite system is bound while smaller subsystems are unbound.Comment: 5 pages, Dedicated to V.B. Belyaev for his 70th birthday, to be included in a jubilee volume, edited by A.K.Motovilov and F.M.Pen'ko

    Stability of the Hydrogen and Hydrogen-like Molecules

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    We present a simple proof of the stability of the hydrogen molecule (M+M+m−m−)(M^+M^+m^-m^-). It does not rely on the proton-to-electron mass ratio M/mM/m being very large, and actually holds for arbitrary values of M/mM/m. Some asymmetric molecules of the type (m1+m2+m3−m4−)(m_1^+m_2^+m_3^-m_4^-) are also stable. Possible applications to molecules containing antiparticles and to exotic hadrons in the quark model are briefly outlined. Revtex Version 3.0, 4 Figures available on request by Fax or Mail

    Borromean molecules

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    For some values of the constituent masses m_i, the hydrogen-like molecule (m_1^+,m_2^+,m_3^-,m_4^-) is stable with respect to spontaneous dissociation into two neutral atoms, while none of its three-body subsystems such as (m_1^+,m_2^+,m_3^-) is stable. This occurs in particular in the neighbourhood of the (M^+,m^+,M^-,m^-) configuration with M/m=2, as for instance for the molecule (p,d,\bar{p},\bar{d}) involving an antiproton and an antideuteron.Comment: 3 pages, Talk given at the XVIII European Few-Body Conference, Bled, Slovenia, September 2002, to app. in Few-Body Sys. Supp

    Hadrons with Two Heavy Quarks

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    We review the spectroscopy and some properties of hadrons containing two charmed quarks, or more generally, two heavy quarks. This includes heavy baryons such as (bcu)(bcu), and possible exotic multiquark states.Comment: Talk given at the CHARM 2000 Workshop, Fermilab, June 1994 to appear in the Proceedings Latex, style file "charm2000" appende

    Baryon spectroscopy and heavy quarks

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    Two topics are briefly reviewed in this talk: the decay of flavored hadrons or quarkonium states involving a baryon--antibaryon pair, and the spectroscopy of heavy baryons containing one, two or three heavy quarks. Some prospects for exotic heavy baryons are also discussed.Comment: 5 pages, 2 figures, Invited talk at "Charm 2010", 4th Int. Workshop on Charm Physics, Oct. 21-24, 2010, IHEP, Beijing, China, to appear in the Proceedings, ed.\ Hai-Bo Li et al., to be published in IJMPC

    Few-Body Problems in Hadron Spectroscopy

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    Some rigorous results can be derived using a very simple approach to hadron spectroscopy, in which a static potential is associated with non-relativistic kinematics. Several regularities of the experimental spectrum are explained by such models. It is underlined that certain methods developed for hadronic physics have found applications in other fields, in particular atomic physics. A few results can be extended to cases involving spin-dependent forces or relativistic kinematics.Comment: Latex with espcrc1, Invited Talk at the 17th European Conference on Few-Body Physics, 11--16 September 2000, Evora, Portugal, to appear in Nuclear Physics A. Misprint corrected p.2, thanks to A. Ga

    Exotic hadrons: review and perspectives

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    The physics of exotic hadrons is revisited and reviewed, with emphasis on flavour configurations which have not yet been investigated. The constituent quark model of multiquark states is discussed in some detail, as it can serve as a guide for more elaborate approaches.Comment: 24 pages, review article, last update of references, to be published in Few-Body Systems, special issue for the 30th anniversary of this journa

    The Role of Flavor in Multiquark Spectroscopy

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    In several mechanisms proposed for multiquark binding, the flavor content of the quark configuration plays a very important role. We shall review some past or recent results on multiquarks dealing with the chromomagnetic interaction and with the spin-independent potential among quarks.Comment: 6 pages, 1 figures, pdflatex, Presented at the International Workshop on Strangeness Nuclear Physics (SNP12), August 27 - 29, 2012, Neyagawa, Osaka, Japa

    Rhombic embeddings of planar graphs with faces of degree 4

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    Given a finite or infinite planar graph all of whose faces have degree 4, we study embeddings in the plane in which all edges have length 1, that is, in which every face is a rhombus. We give a necessary and sufficient condition for the existence of such an embedding, as well as a description of the set of all such embeddings.Comment: 11 pages, 3 figure

    Investigation of the Role of Elastic Unitarity in High-Energy Scattering: Gribov's Theorem and the Froissart Bound

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    We re-examine V. Gribov's theorem of 1960 according to which the total cross-section cannot approach a finite non-zero limit with, at the same time, a diffraction peak having a finite slope. We are very close to proving by an explicit counter-example that elastic unitarity in the elastic region is an essential ingredient of the proof. By analogy, we raise the question of the saturation of the Froissart-Martin bound, for which no examples incorporating elastic unitarity exist at the present time.Comment: 11 pages, 1 figures, latex with sproc.st
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