RT Journal Article T1 A note on the gamma gamma->pi(0)pi(0) reaction in the 1/N expansion of chi PT A1 Dobado González, Antonio A1 Morales, J. AB In this work we present the results of a complete calculation of the gamma gamma --> pi(0) pi(0) amplitude to leading order in the large N approximation (N being the number of Goldstone bosons) up to order m(pi)(2)/F-2, The amplitude turns to be proportional a to that of pi(+)pi(-) --> pi(0) pi(0). In spite of the fact that this factorization property cannot hold in general (as it was recently pointed our by Morgan and Penington), it appears here since in the large N limit only the I = J = 0 channel contributes to the gamma gamma --> pi(0) pi(0) reaction. Moreover it seems to be a reasonable approximation in this case since it is possible to reproduce, as a prediction, the experimental data starting from a one-parameter fit of the pi pi scattering data. PB Elsevier Science BV SN 0370-2693 YR 1996 FD 1996-01-04 LK https://hdl.handle.net/20.500.14352/58735 UL https://hdl.handle.net/20.500.14352/58735 LA eng NO [1] H. Marsiske et al., Crystal Ball COIL, Phys. Rev. D 41 (1990) 3324. [2] S. Weinberg, Physica A 96 (1979) 327; J. Gasser and H. Leutwyler, Ann. Phys. 158 ( 1984) 142; Nucl. Phys. B 250 (1985) 465, 517. [3] J. Bijnens and E Comet, Nucl. Phys. B 296 (1988) 557; J.F. Donoghue, B.R. Holstein and Y.C. Lin, Phys. Rev. D 37 (1988) 2423. [4] D. Morgan and M.R. Pennington, Phys. Len. B 192 (1987) 207; Z. Phys. C 37 (1988) 431; C 48 (1990) 623; Phys. Len. B 272 (1991) 134. [5] A. Dobado and J.R. Pelaez, Z. Phys. C 57 (1993) 501. [6] S. Bellucci, J. Gasser and M.E. Sainio, Nucl. Phys. B 423 (1994) 80; B 431 (1994) 413. [7] C.J.C. Im, Phys. Len. B 281 (1992) 357. [8] R. Casalbuoni, D. Dominici and R. Gatto, Phys. Lett. B 147 ( 1984) 419; M.B. Einhom, Nucl. Phys. B 246 (1984) 75. [9] A. Dobado and J.R. Pelaez, Phys. Len. B 286 ( 1992) 136; A. Dobado, A. López and J. Morales, II Nuovo Cimento (Nuclei, particles and fields) Vol. A 108 (1995) 335. [10] R.S. Chivukula and M. Golden, Nucl. Phys. B 372 (1992) 44. [11] A. Dobado and J. Morales, Phys. Rev. D 52 (1995). [12] D. Morgan and M.R. Pennington, Phys. Len. B 314 (1993) 125. [13] S. Kamefuchi, L. O’Raifeartaigh and A. Salam, Nucl. Phys. 28 (1961) 529. [14] M.J. Dugan and M. Golden, Phys. Rev. D 48 (1993) 4375. [15] L. Rosselet et al., Phys. Rev. D 15 (1977) 574. [16] W. Manner, in: Experimental Meson Spectroscopy (1974). Proc. Boson Conference, ed. D.A. Garelich (AIP, New York, 1974). [17] V. Srinivasan et al., Phys. Rev. D 12 (1975) 681. [18] M. David et al., unpublished; G. Villet et al., unpublished. [19] P Estabrooks and A.D. Martin, Nucl. Phys. B 79 (1974) 301. [20] W. Hoogland et al., Nucl. Phys B 126 (1977) 109. [21] M.J. Losty et al., Nucl. Phys. B 69 (1974) 301. [22] W. Hoogland et al., Nucl. Phys. B 69 (1974) 266. NO © 1996 Elsevier Science B.V..This work has been supported in part by the Ministerio de Education y Ciencia (Spain) (CICYT AEN93- 0776) and COLCIENCIAS (Colombia). The authors thank F. Cornet, J.F. Donoghue, J. Gasser and J.R. Pelaez for useful information and discussions. NO Ministerio de Education y Ciencia (Spain) NO CICYT NO COLCIENCIAS (Colombia) DS Docta Complutense RD 4 may 2024