Search for a High-Mass Diphoton State and Limits on Randall-Sundrum Gravitons at CDF

TL;DR

This paper reports a search for high-mass diphoton resonances at the Fermilab Tevatron, finding no evidence for new particles and setting limits on Randall-Sundrum graviton masses based on observed data.

Contribution

First search for high-mass diphoton states at Tevatron setting new limits on Randall-Sundrum gravitons.

Findings

No excess observed in diphoton mass spectrum

Lower mass limits of 230 GeV/c2 and 850 GeV/c2 for different couplings

Constraints improve previous bounds on Randall-Sundrum models

Abstract

We have performed a search for new particles which decay to two photons using 1.2/fb of integrated luminosity from p-pbar collisions at sqrt(s) = 1.96 TeV collected using the CDF II Detector at the Fermilab Tevatron. We find the diphoton mass spectrum to be in agreement with the standard model expectation, and set limits on the cross section times branching ratio for the Randall-Sundrum graviton, as a function of diphoton mass. We subsequently derive lower limits for the graviton mass of 230 GeV/c2 and 850 GeV/c2, at the 95% confidence level, for coupling parameters (k/M_Pl) of 0.01 and 0.1 respectively.