Search for a massive Di-photon resonance at ∝s = 91 – 172 GeV OPAL Collaboration, K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K. J. Anderson, S. Anderson, S. Arcelli, S. Asai, D. Axen et al. (329 more) Eur. Phys. J. C, 1 1-2 (1998) 31-43 Published online: 27 February 2005 DOI: 10.1007/BF01245796