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Frank E. Close

Publications and source records attributed to Frank E. Close.

At least 19 recordsLinked to original sources

The scientific heritage of Richard Henry Dalitz, FRS (1925-2006)

Professor Richard H. Dalitz passed away on January 13, 2006. He was almost 81 years old and his outstanding contributions are intimately connected to some of the major breakthroughs of the 20th century in particle and nuclear physics. These outstanding contributions go beyond the Dalitz Plot, Dalitz Pair and CDD poles that bear his name. He pioneered the theoretical study of strange baryon resonances, of baryon spectroscopy in the quark model, and of hypernuclei, to all of which he made lasting contributions. His formulation of the "$θ-τ$ puzzle" led to the discovery that parity is not a symmetry of the weak interactions. A brief scientific evaluation of Dalitz's major contributions to particle and nuclear physics is hereby presented, followed by the first comprehensive list of his scientific publications, as assembled from several sources. The list is divided into two categories: the first, main part comprises Dalitz's research papers and reviews, including topics in the history of particle physics, biographies and reminiscences; the second part lists book reviews, public lectures and obituaries authored by Dalitz, and books edited by him. This provides the first necessary step towards a more systematic research of the Dalitz heritage in modern physics. The present 2016 edition updates the original 2006 edition, published in Nucl. Phys. A 771 (2006) 2-7, doi:10.1016/j.nuclphysa.2006.03.007, and 8-25, doi:10.1016/j.nuclphysa.2006.03.008, by including for the first time a dozen or so of publications, found recently in a list submitted to the Royal Society by Dalitz in 2004, that escaped our attention in the original version.

physics.hist-ph

Search for tetraquark candidate Z(4430) in meson photoproduction

We propose a search for the newly discovered tetraquark candidate Z(4430) in photoproduction. Based on the Belle results we show that if Z(4430) is a genuine resonance, its significantly large coupling to $ψ^\primeπ$ will cause it to stand out above the background in $γp\to Z^+(4430) n\to ψ^\prime π^+ n$. We consider the dependence of the cross section for the quantum numbers ($J^{P}=1^{-}$, $1^{+}$ or $0^{-}$).

hep-ph

Selection rules and quark correlations in the $N^*$ resonance spectrum

A "$Λ$ selection rule" for $N^*$ resonances in the presence of QCD mixing effects is identified. Due to the QCD mixing, excitations of {\bf 20}-plets are possible in SU(6). We show that this selection rule is useful for classifying PDG states at N=2, and for clarifying whether strongly correlated diquarks survive for $L > 0$.

hep-ph

Quarks, diquarks and QCD mixing in the $N^*$ resonance spectrum

We identify a "$Λ$ selection rule" for $N^*$ resonances in the presence of QCD mixing effects. We quantify these mixing effects from existing data and predict amplitudes for exciting {\bf 20} representations in SU(6), which are forbidden in strict diquark models. By classifying Particle-Data-Group (PDG) states at N=2, we show that $γN\to KΛ$, $K^*Λ$, $KΣ$, $K^*Σ$, and $J/ψ\to \bar{p}N^*$ are ideal probes of baryon dynamics and for establishing whether strongly correlated diquarks survive for $L > 0$.

hep-ph

Gluonic charmonium resonances at BaBar and Belle?

We confront predictions for hybrid charmonium and other gluonic excitations in the charm region with recently observed structures in the mass range above 3 GeV. The Y(4260), if resonant, is found to agree with expectations for hybrid charmonium. The possibility that other gluonic excitations may be influencing the data in this region is discussed.

hep-ph

Production of $f_0(1710)$, $f_0(1500)$, and $f_0(1370)$ in $J/ψ$ hadronic decays

A coherent study of the production of $f_0^i$ ($i=1$, 2, 3 corresponding to $f_0(1710)$, $f_0(1500)$, and $f_0(1370)$) in $J/ψ\to V f_0 \to V PP$ is reported based on a previously proposed glueball and $Q\bar{Q}$ nonet mixing scheme, and a factorization for the decay of $J/ψ\to V f_0^i$, where $V$ denotes the isoscalar vector mesons $ϕ$ and $ω$, and $P$ denotes pseudoscalar mesons. The results show that the $J/ψ$ decays are very sensitive to the structure of those scalar mesons, and suggest a glueball in the $1.5-1.7$ GeV region, in line with Lattice QCD. The presence of significant glueball mixings in the scalar wavefunctions produces peculiar patterns in the branching ratios for $J/ψ\to V f_0^i\to VPP$, which are in good agreement with the recently published experimental data from the BES collaboration.

hep-ph

The Pentaquark $Θ^+$ in $nK^+$ and $pK^0_S$, and its $Σ^+_5$ partner

A systematic lowering in mass of strangeness ambiguous $pK^0_S$ peaks relative to the $nK^+$ is noted. We discuss how measurement of $γp\to Θ^+ K^0_S\to p K^0_S K^0_S \to pπ^+π^-π^+π^-$ in association with $γp\to Θ^+ K^0_S\to n K^+ K^0_S$ can help to clarify the nature of the narrow baryon state claimed in $p K^0_S$ invariant mass distributions. This can both establish the $Θ^+$ in a single experiment and also reveal, or place severe limits on, the existence of an associated $Σ_5$ pentaquark.

hep-ph

Restricted locality of quark-hadron duality in exclusive meson photoproduction reactions above the resonance region

We show how deviations from the dimensional scaling laws for exclusive processes may be related to a breakdown in the locality of quark-hadron duality, i.e. the "restricted locality". For exclusive reactions like meson photo- and electroproduction above the resonance region, we explore the effects arising from such a local duality breaking and propose that it can be a possible source for oscillations about the smooth quark counting rule predicted by pQCD in the 90-degree differential cross sections.

hep-ph

Photoproduction of $Θ^+$ and other pentaquark states

We present constraints on the {\it relative} photoproduction cross sections of positive parity pentaquark states, $Σ_5$, $Λ_5$, and $N_5$, based on a minimum phenomenology gained in $γN \to K Θ^+$ and their baryon-meson couplings as in the work of Close and Dudek. The possibility of anomalous signals in $γp \to K^0_S (Θ^+;Σ_d^+)$ is discussed. We emphasise the importance of comparing $γN \to K Θ^+$ with "conventional" states such as $γN \to K Σ(1660)$.

hep-ph

The D*0 D0bar threshold resonance

Tests are discussed to distinguish c cbar, hybrid charmonium and molecular interpretations of the narrow Belle resonance at 3872 MeV.

hep-ph

Locality of quark-hadron duality and deviations from quark counting rules above resonance region

We show how deviations from the dimensional scaling laws for exclusive processes may be related to a breakdown in the locality of quark-hadron duality. The essential principles are illustrated in a pedagogic model of a composite system with two spinless charged constituents, for which a dual picture for the low-energy resonance phenomena and high-energy scaling behavior can be established. We introduce the concept of "restricted locality" of quark-hadron duality and show how this results in deviations from the pQCD quark counting rules above the resonance region. In particular it can be a possible source for oscillations about the smooth quark counting rule, as seen e.g. in the 90-degree differential cross sections for $γp\to π^+ n$.

hep-ph

On baryon-antibaryon coupling to two photons

We discuss recent claims that $p\bar{p} \to γγ$ may be described by a generalized parton picture. We propose that quark-hadron duality provides a justification for the effective dominance of the "handbag" diagram assumed in recent literature, and that handbag diagrams may dominate phenomena in kinematic regions far more extensive than that might be expected from pQCD alone.

hep-ph

Pedagogic model for Deeply Virtual Compton Scattering with quark-hadron duality

We show how quark-hadron duality can emerge for valence spin averaged structure functions, and for the non-forward distributions of Deeply Virtual Compton Scattering. Novel factorisations of the non-forward amplitudes are proposed. Some implications for large angle scattering and deviations from the quark counting rules are illustrated.

hep-ph

Scalar mesons above and below 1 GeV

We show that two nonets and a glueball provide a consistent description of data on scalar mesons below 1.7 GeV. Above 1 GeV the states form a conventional (q bar q) nonet mixed with the glueball of lattice QCD. Below 1 GeV the states also form a nonet, as implied by the attractive forces of QCD, but of more complicated nature. Near the center they are 4 quark states of the Jaffe type in S-wave, with some (q bar q) in P-wave, but further out they rearrange in colour to two colourless (q bar q) pairs and finally as meson-meson states. A simple effective chiral model for such a system with two scalar nonets can be made involving two coupled linear sigma models. One of these could be looked upon as the Higgs sector of nonpertubative QCD.

hep-ph

Light Hadron Spectroscopy: Theory and Experiment

Rapporteur talk at the Lepton-Photon Conference, Rome, July 2001: reviewing the evidence and strategies for understanding scalar mesons, glueballs and hybrids, the gluonic Pomeron and the interplay of heavy flavours and light hadron dynamics. Dedicated to the memory of Nathan Isgur, long-time collaborator and friend, whose original ideas in hadron spectroscopy formed the basis for much of the talk.

hep-ph

The origins of quark-hadron duality: How does the square of the sum become the sum of the squares?

Bloom-Gilman duality demonstrates empirically that the electroproduction of $N^*$'s at low momentum transfers averages smoothly around the scaling curve measured at large momentum transfers. The latter is proportional to the sum of the squares of the constituent charges whereas the former involves the coherent excitation of resonances and is driven by the square of summed constituent charges. We determine the minimal necessary conditions for this equality to be realised so that duality can occur and consider the implications for a range of processes that may be studied soon at CEBAF.

hep-ph

Filtering glueball from $q\bar{q}$ production in proton proton or double tagged $e^+e^- \to e^+e^-R$ and implications for the spin structure of the Pomeron

The production of $J^{PC} = 1^{++},0^{-+}$ and $2^{-+}$ mesons in double tagged $e^+e^- \to e^+e^-R$ is calculated and found to have the same polarisation and dynamical characteristics as observed in $pp \to ppR$. Implications for the spin structure of the Pomeron are considered. Production of $0^{++},2^{++}$ mesons in these two processes may enable the dynamical nature of these mesons to be determined.

hep-ph