[1] Mattson M et al (SELEX Collaboration) 2002 Phys. Rev.
Lett. 89 112001

[2] Moinester M A et al (SELEX Collaboration) 2003 Czech. J.
Phys. 53 B201

[3] Ocherashvili A et al (SELEX Collaboration) 2005 Phys.
Lett. B 628 18

[4] Falk A F, Luke M E, Savage M J and Wise M B 1994
Phys. Rev. D 49 555

[5] Kiselev V V, Likhoded A K and Shevlyagin M V 1994
Phys. Lett. B 332 411

[6] Berezhnoi A V, Kiselev V V and Likhoded A K 1996
Phys. Atom. Nucl. 59 870 [1996 Yad. Fiz. 59 909]

[7] Baranov S P 1996 Phys. Rev. D 54 3228

[8] Berezhnoi A V, Kiselev V V, Likhoded A K and Onishchenko A I 1998
Phys. Rev. D 57 4385

[9] Ma J P and Si Z G 2003 Phys. Lett. B 568 135

[10] Chang C H, Qiao C F, Wang J X and Wu X G 2006 Phys.
Rev. D 73 094022

[11] Chang C H, Ma J P, Qiao C F and Wu X G 2007 J. Phys. G
34 845

[12] Li S Y, Si Z G and Yang Z J 2007 Phys. Lett. B
648 284

[13] Ginzburg I F, Kotkin G L, Panfil S L, Serbo V G and Telnov
V I 1984 Nucl. Instrum. Methods A 219 5

[14] Bodwin G T, Braaten E and Lepage G P 1995 Phys. Rev. D
51 1125 [1997 Erratum ibid. D 55 5853]

[15] Brambilla N, Vairo A and Rosch T 2005 Phys. Rev. D
72 034021