Search for Resonant Diphoton Production with the D0 Detector

This is the publisher's version, also available electronically from http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.102.231801.We present a search for a narrow resonance in the inclusive diphoton final state using ∼2.7 fb(−1) of data collected with the D0 detector at the Fermilab Tevatron pp-bar Collider. We observe good agreement between the data and the background prediction, and set the first 95% C.L. upper limits on the production cross section times the branching ratio for decay into a pair of photons for resonance masses between 100 and 150 GeV. This search is also interpreted in the context of several models of electroweak symmetry breaking with a Higgs boson decaying into two photons