New New-Phenomena Results from Dzero

TL;DR

This paper reports on searches for specific high-energy photon and jet events in proton-antiproton collisions, finding no excess beyond background expectations, and interprets the null results within supersymmetry and monopole models.

Contribution

It presents the first search for certain diphoton and photon-plus-jet events at the Tevatron and sets limits on supersymmetric and monopole models based on null results.

Findings

No excess events observed beyond background expectations.

Results constrain supersymmetric model parameters.

Limits set on Dirac monopole production cross sections.

Abstract

We have searched for diphoton events (\ggmet) with large missing transverse momentum, $\gamma\rlap{\kern0.25em/}E_T$ events (\gmetjj) with two or more jets, and diphoton events ($\gamma\gamma$) with high transverse energies in $p\bar p$ collisions at $\sqrt{s} = 1.8$ TeV using approximately 100~pb$^{-1}$ of data collected with the D\O detector at the Fermilab Tevatron in 1992--1996. No excess of events beyond the expected backgrounds is observed. The null results are interpreted in supersymmetric models with a dominant $\tilde\chi^0_2\to\gamma\tilde\chi^0_1$ decay and in terms of Dirac pointlike monopole production.