Search for Randall-Sundrum Gravitons with $1{\mathrm{fb}}^{-1}$ of Data from $p\overline{p}$ Collisions at $\sqrt{s}=1.96\mathrm{TeV}$

We search for decays of Kaluza-Klein excitations of the graviton in the Randall-Sundrum model of extra dimensions to $e^{+}{e}^{-}$ and $\gamma \gamma$ in $1{\mathrm{fb}}^{-1}$ of $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ collected by the D0 detector at the Fermilab Tevatron. We set 95% confidence level upper limits on the production cross section times branching fraction, which translate into lower limits on the mass of the lightest excitation between 300 and 900 GeV for values of the coupling $k/{\overline{M}}_{\mathrm{Pl}}$ between 0.01 and 0.1.

Figure 1

Invariant mass spectrum from data. Superimposed is the fitted total background, the diphoton background, and the fitted contribution from events with misidentified clusters.

Figure 2

Invariant mass spectrum from data. Superimposed is the fitted total background, the diphoton background, and the fitted contribution from events with misidentified clusters. The gray shaded histogram shows the signals expected from gravitons with $M_1=300$, 600, and 900 GeV and $k/{\overline{M}}_{\mathrm{Pl}}=0.1$ on top of the total background.

Figure 3

The 95% C.L. upper limit on $\sigma (p\overline{p}\to G+X)B(G\to e^{+}{e}^{-})$ from $1{\mathrm{fb}}^{-1}$ of data compared with expected limit and theoretical predictions for different couplings $k/{\overline{M}}_{\mathrm{Pl}}$.

Figure 4

The 95% C.L. upper limit on $k/{\overline{M}}_{\mathrm{Pl}}$ versus $M_1$ from $1{\mathrm{fb}}^{-1}$ of data compared with expected limit and our previously published exclusion [3]. The hatched area is excluded by precision electroweak measurements [15].