Two-meson annihilation of a nucleon and antinucleon

Henley, Ernest M.; Oka, Toshitaka; Vergados, J.D.

doi:10.1016/0370-2693(86)90797-5

Cited by 30 publications

(27 citation statements)

References 6 publications

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“…To examine these we take the predictions of two microscopic calculations for which there are available the pure quark model overlaps M 2 without initial state distortion and phase space corrections; especially the two meson rearran- Table 4. Selection rules for the up to now experimentally observed two meson decays: blanc = allowed quantum numbers, shaded = forbidden ones, >> indicates the experimentally seen dominance of the T= 0 components for s-as well as for p-waves in the = -p + channel [4]) and a calculation of Henley et al [6] with an effective 3S I gluon annihilation vertex (G2). These matrix elements do not contain the pion suppression factors introduced by Green et al [9] to account for the special nature of the pion wavefunction, being only partially a q~-state.…”

Section: Its = ~ Im((nn(ts)i V If) F 9 (Hf-e+i~) -1 (Fl V Inr(ts)))mentioning

confidence: 98%

“…A QED analog is the (rare) total annihilation of muonium and antimuonium #+ e-+/.t-e + --, ? 's (6) whose range is very short on the atomic scale, although the incoming atoms are quite extended.…”

Section: Annihilation Range From Protonium Statesmentioning

confidence: 99%

“…For instance the contribution of annihilation into three mesons to the NN scattering has been calculated in [6]. The spin-isospin dependence of the microscopically founded annihilation potential gives less important effects than the one originating from the long range boson exchange forces.…”

Section: Its = ~ Im((nn(ts)i V If) F 9 (Hf-e+i~) -1 (Fl V Inr(ts)))mentioning

confidence: 99%

“…These matrix elements do not contain the pion suppression factors introduced by Green et al [9] to account for the special nature of the pion wavefunction, being only partially a q~-state. Furthermore in [4,6] the t/-and q'-wavefunctions used to calculate M 2 are crudely approximated by the ideal mixing limit ~/=11'= t/id/~/2, with rl~a=(u~+dd)/]/2. An alternative analysis could be done for the more recent [9], where a final state interaction via a meson-meson rescattering mechanism is introduced.…”

Section: Its = ~ Im((nn(ts)i V If) F 9 (Hf-e+i~) -1 (Fl V Inr(ts)))mentioning

confidence: 99%

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Protonium annihilation in optical models

Carbonell

Ihle

Richard

1989

Z. Physik A - Atomic Nuclei

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We calculate the wave-functions, energy shifts and widths of low lying protonium states using different optical potentials (Dover-Richard, Kohno-Weise). The importance of tensor and isospin coupling is studied and the initial state distortion is compared for protonium annihilation and pp annihilation in flight at low energy. We study the range of distances at which annihilation actually occurs in protonium. We also analyse the effect of the initial state interaction on two meson branching ratios and underline that it may dramatically change the predictions of those microscopic models which are based only on phase space and simple quark diagrams.

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Section: Its = ~ Im((nn(ts)i V If) F 9 (Hf-e+i~) -1 (Fl V Inr(ts)))mentioning

confidence: 98%

Section: Annihilation Range From Protonium Statesmentioning

confidence: 99%

Section: Its = ~ Im((nn(ts)i V If) F 9 (Hf-e+i~) -1 (Fl V Inr(ts)))mentioning

confidence: 99%

Section: Its = ~ Im((nn(ts)i V If) F 9 (Hf-e+i~) -1 (Fl V Inr(ts)))mentioning

confidence: 99%

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Protonium annihilation in optical models

Carbonell

Ihle

Richard

1989

Z. Physik A - Atomic Nuclei

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“…It has been shown that the so-called SP o model [1,2] in which a quark(q)-antiquark(~) pair are created from, or annihilated into, the vacuum is related to QCD and flux-tube approximations thereto [3]. In recent years an effective perturbative approach [4] or "3S1" model [5,2] 1 has also been shown to be effective in describing reactions in which a q ~ pair is annihilated or created. Reactions in which these models have been applied include nucleon-antinucleon (NbT) annihilation [2].…”

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confidence: 99%

A new model forN $$\bar N$$ annihilation

Alberg

Henley

Wilets

1988

Z. Physik A - Atomic Nuclei

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A new quark model for Nb7 annihilation is proposed. It is argued that a linear superposition of the so-called SP 0 and SS t models is more consistent with QCD and the inclusion of quark degrees of freedom in NN scattering, and is also suggested by the data. A comparison is made, in Born approximation, with the angular distribution for p~AA. PACS" 25.10+ 5; 12.40.Qq Applications of QCD to low energy hadronic interactions require numerical calculations on a lattice or models. Among the latter are bag models, topological and nontopological soliton models, and flux-tube type models. It has been shown that the so-called SP o model [1,2] in which a quark(q)-antiquark(~) pair are created from, or annihilated into, the vacuum is related to QCD and flux-tube approximations thereto [3]. In recent years an effective perturbative approach [4] or "3S1" model [5,2] 1 has also been shown to be effective in describing reactions in which a q ~ pair is annihilated or created. Reactions in which these models have been applied include nucleon-antinucleon (NbT) annihilation [2].A number of recent letters and papers argue that one model (e.g. 3P0) is superior to the other (e.g. "3S 1 ") [6]. We wish to argue in this short article that such comparisons should not be made, but rather, that these two models emphasize different aspects of QCD. Furthermore a description consistent with NN scattering models also leads to a superposition of the 3P 0 and "sst" models as components of an overall scheme. We show that this is also suggested by the data.Almost all models which incorporate quark-gluon degrees of freedom in the description of the NN inter-1 The name sS 1 is a misnomer because the virtual gluon exchanged between quarks/antiquarks has both transverse (je = 1 -) and longitudinal (JP=0 +) or Coulomb components. It thus is not a pure (qO) sS1 model, and we use quotes for that reason action [7] require two parts: (1) a short distance one gluon exchange force and (2) a long distance scalar confining force. Indeed the combination of the one gluon exchange and a linear confining force reproduces the spectra of heavy quarkonia systems such as c g, b b, and those of one light and one heavy quark such as D ~ D ~ [8]. For light quark (u, d, s) systems the confining forces are often taken to be harmonic (~ r 2) in potential models [7]. If we begin with a field theory and use crossing symmetry, then consistency requires that similar forces should be present in the NN system, i.e. a short range one gluon exchange and a long range scalar interaction.The important features which appear to be present in both nuclear and quark systems is that they are dominated by scalar (or pseudoscalar) and vector interactions. In the NN system these are described, at large distances, by ~, a, p, and co exchanges. In q q and q c~ systems they arise from gluon exchange and the confining force. There is good evidence [9] that the confining force is a scalar one which is independent of flavor, whereas the one gluon force is clearly a colored-vector exchange one.In ...

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A Review of N $$\overline N$$ Annihilation Mechanisms

Green

1990

Antiproton-Nucleon and Antiproton-Nucleus Interactions

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Two-meson annihilation of a nucleon and antinucleon

Cited by 30 publications

References 6 publications

Protonium annihilation in optical models

Protonium annihilation in optical models

A new model forN $$\bar N$$ annihilation

A Review of N $$\overline N$$ Annihilation Mechanisms

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