Diquark model for protonium annihilation into two mesons

Z. Physik A - Hadrons and Nuclei

Markushin

et al. 1996

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Abstract. The leading two meson doorway contributions to the reaction tip ~ r due to K*/( and pp intermediate states are calculated beyond unitarity approximation. The dependence of the results on the off-shell parametrization is explored and the effect of the finite width of the propagating mesons is estimated. The rates obtained from the rescattering mechanisms are in agreement with the data for ;0p ~ r annihilation at rest. The vertices entering the calculation do not require any unexplained OZI violation, in particular no substantial sg configuration in the nucleon appears to be needed.

Section: Discussion Of Resultsmentioning

confidence: 95%

“…In the absence of experimental data for the BR(p#(3S1) ~ p+p-(I = 1)) the value in (44) has been taken from the theoretical model [10] which overall well describes the measured two-meson branching ratios. The width of the 3SI state was assumed to be Fp#(~s~)_~u = 1 keV (see e.g.…”

Section: + (2ae -52 --C 2) Log C + B ] C-b +2b(c-a) With a B And mentioning

confidence: 99%

Two meson doorway calculation forpp → Øπ including off-shell effects and the OZI rule

Gortchakov

Z. Physik A - Hadrons and Nuclei

Markushin

et al. 1996

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“…From (15) and Fp ~ ~ ~ + ~o = 151 MeV we determine g2. In order to obtain the strength of the elementary annihilation vertex we use the branching ratio I~ffp(3SI)~P+P--24 x 10 -3 (25) Ftot from the theoretical estimate [13] which should represent a conservative interpolation of observed two meson branching ratios [14]. 3 We remark that in the case of K*/( rescattering, Fig.…”

Section: Tr -+ O-~ + = G4eu~ Eu(p) P~(p)e~( ~) P~( (~)mentioning

confidence: 99%

Rescattering mechanisms for $$\bar p$$ p??X and the OZI rule re-examined

Z. Physik A - Hadrons and Nuclei

1995

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Abstract. The OZI suppressed reactions Dp--,q~b and ~p-, ~rq~ are reanalyzed, evaluating the unitarity contributions from two meson intermediate states with full spin, partially correcting earlier results. An estimate for ~p -, ~rg~b without spin is also given. Together with earlier VDM results for ,~p--* d?? the conservative estimates reported here easily explain the observed rates for all the q5 meson channels considered. PACS" 13.75Cs; 12.40Vv

“…The biggest deviation from the OZI prediction for hadronic channels occurs for the φπ 0 final state and has led to speculations about the internal structure of the nucleon suggesting a large ss component in the wave function [9][10][11]. Earlier analysis [12][13][14][15][16][17][18][19][20][21] has shown that two meson doorway contributions have the correct magnitude to explain the experimental branching ratio for this reaction. The present paper extends the preceding calculations by including three meson doorway states.…”

Section: Introductionmentioning

confidence: 99%

Higher order two step mechanisms in nucleon antinucleon annihilation and the OZI rule

Rotz

Markushin

2000

EPJ A

We evaluate three meson doorway mechanisms for nucleon-antinucleon annihilation at rest for the first time. Detailed results are presented for the final state φπ 0 originating from the 3 S 1 initial state and for the φρ channel originating from 1 S 0 . The results presented also include the improved contributions from two meson doorway states and from the tree diagrams. For all the channels considered a consistent explanation of large and small OZI violations emerges.