Abstract
We investigate the origin of the attraction in theK¯K channel around the threshold by introducing an additional channel to theππ andK¯K channels in a separable potential formalism assuming, in general, no direct interaction in theK¯K channel. To reproduce the features of the data, we find that the threshold of the additional channel is much above thef 0(975) meson position. We show that this three-channel problem can be reduced to an effective two-channel problem where thef 0(975) behaves as if it were aK¯K molecule bound by the coupling to the exotic channel. This picture is also supported by the fact that a single pole only, in the complexK¯K momentum plane, is associated to thef 0(975) meson. Various physical observables, like the decay branching ratio and theK¯K scattering length, are then discussed in an effective two-channel framework.
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Narison, S.: Hadron '89. Binon, F., Frère, J.-M., Peigneux, J.-P. (eds.) p. 181. Paris: Frontières 1989; Truong, T.N.: ibid., p. 645; Weinstein, J.: ibid., p. 233; Bugg, D.V.: ibid., p. 567; Morgan, D., Pennington, M.R.: ibid., p. 297 and Z. Phys. C — Particles and Fields48, 623 (1990); Beveren, E. van, Rijken, T.A., Metzger, K., Dullemond, C., Rupp, G., Ribeiro, J.E.: Z. Phys. C — Particles and Fields30, 615 (1986); Eremyan, Sh.S., Nazaryan, A.E.: Yad. Fiz.46, 1774 (1987) [transl. Sov. J. Nucl. Phys. 46,1061 (1987)]; Landsberg, L.G.: Serpukhov Report IFWE 89-54 (1989); Efimov, G.V., Ivanov, M.A., Mashnik, S.G.: Dubna Reports E2-89-780 (1989) and E2-90-518 (1990); Chang, C., Li, X., Wang, J.: Beijing Institute of Theoretical Physics Report AS-ITP-90-09 (1990)
Weinstein, J., Isgur, N.: Phys. Rev. D41, 2236 (1990); Phys. Rev.D43, 95 (1991)
Morgan, D., Pennington, M.R.: Phys. Lett. B258, 444 (1991)
Achasov, N.N., Shestakov, G.N.: Sov. Phys. Usp.34, 471 (1991)
Cannata, F., Dedonder, J.-P., Leśniak, L.: Z. Phys. A — Atomic Nuclei334, 457 (1989), thereafter referred to as I; Phys. Lett.B207, 115 (1988) and Report INP 1554/PH, Cracow, July 1991; Leśniak, L.: Hadron '89 loc. cit., p. 269
Dover, C.B., Gutsche, T., Faessler, A.: Phys. Rev. C43, 379 (1991)
Tornqvist, N.A.: Phys. Rev. Lett.49, 624 (1982)
Grach, I.L., Kerbikov, B.O.: Z. Phys. A — Atomic Nuclei337, 315 (1990)
Bogdanova, L.N., Hale, G.M., Markushin, V.E.: Phys. Rev. C44, 1289 (1991)
Alde, D., Binon, F., Brincman, C., Donskov, S.V., Dufournaud, J., Duteil, P., Gouanére, M., Inyakin, A.V., Kachanov, V.A., Kakauridze, D.B., Khaustov, G.V., Knapp, E.A., Kulik, A.V., Lac, CD., Lagnaux, J.P., Lednev, A.A., Mikhailov, Yu.V., Mouthuy, Th., Obraztsov, V.F., Peigneux, J.P., Possoz, A., Prokoshkin, Yu.D., Rodnov, Yu.V., Sadovsky, S.A., Shagin, P.M., Sillou, D., Singovsky, A.V., Stroot, J.P., Sugonyaev, V.P.: Nucl. Phys. B269, 485 (1986); Karch, K.H.: Report DESY91-094 (1991); Pennington, M.R.: Report BNL-41936 (1988)
Lohse, D., Durso, J.W., Holinde, K., Speth, J.: Phys. Lett. B234, 235 (1990); Nucl. Phys.A516, 513 (1990)
Leśniak, L., Maillet, J.-P.: (work in progress) see also Siegel, P.B., Weise, W.: Phys. Rev. C38, 2221 (1988)
Particle Data Group: Phys. Lett. B239, 1 (1990); Armstrong, T.A., Benayoun, M., Beusch, W., Bloodworth, I.J., Carney, J.N., Childs, R., Evangelista, C, French, B.R., Ghidini, B., Girone, M., Jacholkowski, A., Kahane, J., Kinson, J.B., Kirk, A., Knudson, K., Leuti, V., Leruste, Ph., Malamant, A., Narjoux, J.L., Navach, F., Palano, A., Quercigh, E., Redaelli, N., Rossi, L., Sené, M., Sené, R., Stassinaki, M., Trainor, M.T., Vassiliadis, G., Villalobos Baillie, O., Votruba, M.F.: Z. Phys. C — Particles and Fields51, 351 (1991); Breakstone, A., Campanini, R., Crawley, H.B., Dallavalle, G.M., Deninno, M.M., Doroba, K., Drijard, D., Fabbri, F., Firestone, A., Fischer, H.G., Frehse, H., Geist, W., Giacomelli, G., Gokieli, R., Gorbics, M., Hanke, P., Heiden, M., Herr, W., Isenhower, L.D., Kluge, E.E., Lamsa, J.W., Leacock, R.A., Lohse, T., Mankel, R., Meyer, W.T., Mornacchi, G., Nakada, T., Panter, M., Putzer, A., Rauschnabel, K., Rensch, B., Rimondi, F., Schmelling, M., Siroli, G.P., Skeens, J.D., Sosnowski, R., Szczekowski, M., Ullaland, O., Wegener, D., Yeung, R.: Z. Phys. C — Particles and Fields48, 569 (1990)
Grayer, G., Hyams, B., Jones, C., Schlein, P., Weilhammer, P., Blum, W., Dietl, H., Koch, W., Lorentz, E., Lütjens, G., Männer, W., Meissburger, J., Ochs, W., Stierlin, U.: Nucl. Phys. B75, 189 (1974)
Wetzel, W., Freudenreich, K., Gentit, F.X., Muhlemann, P., Beusch, W., Birman, A., Websdale, D., Astbury, P., Harckham, A., Letheren, M.: Nucl. Phys. B115, 208 (1976)
Sano, H., Nagae, T., Tokushuku, K., Sasaki, S., Sekimoto, M., Arai, I., Manabe, A., Nunokawa, H., Aoki, K., Sakamoto, H., Chiba, J., Nakai, K.: Abstract III-85, PANICXII Conference, Boston 1990
Boyer, J., Butler, F., Gidal, G., Abrams, G., Amidei, D., Baden, A.R., Gold, M.S., Golding, L., Goldhaber, G., Haggerty, J., Herrup, D., Juricic, I., Kadyk, J.A., Levi, M.E., Nelson, M.E., Rowson, P.C., Schnellman, H., Schmidke, W.B., Sheldon, P.D., Trilling, G.H., Wood, D.R., Barklow, T., Boyarski, A., Burchat, P., Burke, D.L., Cords, D., Dorfan, J.M., Feldman, G.J., Gladney, L., Hanson, G., Hayes, K., Hollebeek, R.J., Innes, W.R., Jaros, J.A., Karlen, D., Lankford, A.J., Larsen, R.R., Le Claire, B.W., Lockyer, N.S., Lüth, V., Ong, R.A., Perl, M.L., Richter, B., Riles, K., Yelton, J.M., Schaard, T.: Phys. Rev. D42, 1350 (1990)
Karch, K.H. (Crystal Ball Coll.): Report DESY91-022 (1991)
Rosselet, L., Extermann, P., Fischer, J., Guisan, O., Mermod, R., Sachot, R., Diamant-Berger, A.M., Bloch, P., Bunce, G., Devaux, B., Do-Duc, N., Marel, G., Turlay, R.: Phys. Rev. D15, 574 (1977)
Au, K.L., Morgan, D., Pennington, M.R.: Phys. Rev. D35, 1633 (1987)
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Unité de Recherche des Universités Paris 11 and 6 associée au CNRS
One of us (L.L.) would like to thank the French Ministry of Research and Technology for the attribution of a grant which permitted the completion of this study.