Search for Large Extra Dimensions in the Monojet + Missing ET Channel at D0

Abstract

We present a search for large extra dimensions (ED) in p-pbar collisions at a center-of-mass energy of 1.8 TeV using data collected by the D0 detector at the Fermilab Tevatron in 1994-1996. Data corresponding to 78.8 +/- 3.9 pb^-1 are examined for events with large missing transverse energy, one high-p_T jet, and no isolated muons. With no excess beyond the background prediction from the standard model, we place limits on the fundamental Planck scale of 1 TeV (0.6 TeV) for 2 (7) ED.

Figures (2)

• Figure 1: (a) Comparison of data (points with error bars) with expected background (dashed histogram), and the sum of background and signal for $n$ = 2, $M_D$ = 800 GeV (dotted histogram), as a function of $\hbox{${\hbox{$E$/}}_T$}$, for $E_T(j_1) > 150$ GeV, $\hbox{${\hbox{$E$/}}_T$} > 150$ GeV, and $E_T(j_2) < 50$ GeV; and (b) comparison of $\hbox{${\hbox{$E$/}}_T$}$ for data with $E_T(j_1) > 115$ GeV, $\hbox{${\hbox{$E$/}}_T$} > 115$ GeV, and $E_T(j_2) < 40$ GeV with expected background.
• Figure 2: The 95$\%$ C.L. exclusion contours on the fundamental Planck scale ($M_D$) and number of extra dimensions ($n$) for monojet production at DØ (solid lines). The dashed curves correspond to limits from LEP, and the dotted curve is the limit from CDF, both for $\gamma+G_{\rm KK}$ production.