Search for $W^{\prime }$ Bosons Decaying to an Electron and a Neutrino with the D0 Detector

This Letter describes the search for a new heavy charged gauge boson $W^{\prime }$ decaying into an electron and a neutrino. The data were collected with the D0 detector at the Fermilab Tevatron $p\overline{p}$ Collider at $\sqrt{s}=1.96\mathrm{TeV}$, and correspond to an integrated luminosity of about $1{\mathrm{fb}}^{-1}$. Lacking any significant excess in the data in comparison with known processes, an upper limit is set on ${\sigma }_{W^{\prime }}\times B(W^{\prime }\to e\nu )$, and a $W^{\prime }$ boson with mass below 1.00 TeV can be excluded at the 95% C.L., assuming standard-model-like couplings to fermions. This result significantly improves upon previous limits and is the most stringent to date.

Figure 1

Transverse mass $m_T$ distributions for different masses of the $W^{\prime }$ boson (generator level, pythia). The event numbers correspond to an integrated luminosity of $1{\mathrm{fb}}^{-1}$.

Figure 2

Comparison between data and background prediction: (a) distribution of the transverse mass $m_T$; (b) distribution of the electron transverse energy $E_T^{\mathrm{el}}$ in events with $m_T>140\mathrm{GeV}$; (c) distribution of the ratio of electron transverse energy and ${\mathrm{E̸}}_T$ in events with $m_T>140\mathrm{GeV}$. The signal is shown for two different masses of the $W^{\prime }$ boson.

Figure 3

The observed and expected 95% C.L. limits on the cross section as a function of the mass of the $W^{\prime }$ boson, including statistical and systematic uncertainties. The expected limit assumes a background-only hypothesis. The theoretical expectation is displayed with its uncertainty. Also shown is the D0 Run I limit [5].