Summary
The reaction\(\bar pp \to \bar \Lambda \Lambda \) has been studied in a bubble chamber experiment at eight incident momenta between 1.50 and 2.06 GeV/c. The differential cross-section, the polarization and the spin correlation coefficients have been measured. They have been compared with the prediction of two theoretical models: the K-meson conspiracy and the exchange of the K*K** degenerate trajectory associated with a Regge cut. The latter model gives the best representation of the data.
Riassunto
Si è studiata la reazione\(\bar pp \to \bar \Lambda \Lambda \) in un esperimento con camera a bolle a otto impulsi incidenti tra 1.50 e 2.06 GeV/c. Si sono misurati la sezione d’urto differenziale, la polarizzazione e i coefficienti della correlazione di spin. Si sono confrontati con le predizioni di due modelli teorici: la « cospirazione » del mesone K e lo scambio della traiettoria degenerata K*K** associata a un taglio di Regge. Quest’ultimo modello dà la migliore rappresentazione dei dati.
Реэюме
С помошью пуэырьковой камеры исследуется реакция\(\bar pp \to \bar \Lambda \Lambda \) при восьми эначениях начальных импульсов в области между 1.50 и 2.06 ГзВ/с. Были иэмерены дифференциальное поперечное сечение, поляриэация и спиновые корреляционные козффициенты. Полученные реэультаты сравниваются с предскаэаниями двух теоретических моделей: «конспирация» К-меэона и обмен K*-K** вырожденной траекторией, свяэанной с Редже-раэреэом. Последняя модель дает наилучщее описание полученных данных.
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References
B. Y. Oh, P. S. Eastman, Z. Ming Ma, D. L. Parker, G. A. Smith andR. J. Sprafka:Nucl. Phys.,51 B, 57 (1973).
J. Button, Ph. Eberhard, G. R. Kalbfleisch, J. E. Lannutti, G. R. Lynch, B. C. Maglic, M. L. Stevenson andN. H. Xuong:Phys. Rev.,121, 1788 (1961).
S. Vallet: Thèse, Université de Neuchâtel (1972).
V. Vuillemin, M. Gailloud, Ph. Rosselet, R. Brenzikofer, M. Bogdanski, E. Jeannet, S. Vallet, L. de Billy, H. Briand, J. Duboc, F. Lévy, D. N. Edwards, M. A. Houlden, E. F. Clayton andP. J. Negus:Nuovo Cimento,33 A, 133 (1976);B. Jayet, M. Gailloud, Ph. Rosselet, M. Bogdanski, E. Jeannet, C. J. Campbell, P. J. Negus, M. A. Houlden andA. S. Thompson:Nuovo Cimento, 45 A, 351 (1978).
B. Jayet: Thèse, Ecole Polytechnique Fédérale de Lausanne (1976).
N. Kwak, J. E. Manweiler andM. L. Nicholas:Nuovo Cimento,23 A, 610 (1974).
J. Badier, A. Bonnet, Ph. Briandet andB. Sadoulet:Phys. Lett.,25 B, 152 (1967).
G. P. Fisher, V. Domingo, A. J. Eide, J. von Krogh, L. Marshall Libby, R. Sears, D. Bohning, W. Kernan andL. Schroeder:Phys. Rev.,161, 1335 (1967).
B. Musgrave, G. Petmezas, L. Riddiford, R. Böck, E. Fett, B. R. French, J. B. Kinson, Ch. Peyrou, M. Szeptycka, J. Badier, M. Bazin, L. Blaskovic, B. Equer, J. Huc, S. R. Borenstein, S. J. Goldsack, D. H. Miller, J. Meyer, D. Revel, B. Tallini andS. Zylberajch:Nuovo Cimento,35 A, 735 (1965).
C. Baltay, J. Sandweiss, H. D. Taft, B. B. Culwick, J. K. Kopp, R. I. Louttit, R. P. Shutt, A. M. Thorndike andM. S. Webster:Phys. Rev.,140, B 1027 (1965).
H. W. Atherton, B. R. French, J. P. Moebes andE. Quercigh:Nucl. Phys.,69 B, 1 (1974).
H. W. Atherton, L. M. Celnikier, B. French, J. B. Kinson, K. Myklebost, J. Pernegr, E. Quercigh andB. Sadoulet:Phys. Lett.,30 B, 494 (1969).
C. Y. Chien, J. Lach, J. Sandweiss, H. D. Taft, N. Yeh, Y. Oren andM. Webster:Phys. Rev.,152, 1171 (1966).
We used a different normalization in the communication presented at theThird European Symposium on Antinucleon-Nucleon Interactions (Stockholm, 1976).
D. V. Volkov andV. N. Gribov:Sov. Phys. JETP,17, 720 (1963).
R. J. N. Phillips:Nucl. Phys.,2 B, 394 (1967).
F. J. Hadjioannou andP. N. Poulopoulos:Lett. Nuovo Cimento,3, 384 (1970).
G. Plaut:Nucl. Phys.,35 B, 221 (1971).
A. C. Irving, A. D. Martin andC. Michael:Nucl. Phys.,32 B, 1 (1971).
The fitted differential cross-sections based on this model and on the parametrization by two exponentials are almost undistinguishable. In fact these two descriptions can be shown to be formally equivalent as long as helicity-flip terms are negligible (see ref. (5)).
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Work supported in part by the Swiss National Science Foundation and by the U.K. Science Research Council.
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Jayet, B., Gailloud, M., Rosselet, P. et al. The reaction\(\bar pp \to \bar \Lambda \Lambda \) between 1.50 and 2.06 GeV/e. Nuov Cim A 45, 371–388 (1978). https://doi.org/10.1007/BF02730077
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DOI: https://doi.org/10.1007/BF02730077