Search for pair production of light scalar top quarks in p(p)over-bar collisions at root s=1.8 TeV

Abstract

Using 85.2+/-3.6 pb(-1) of p (p) over bar collisions collected at roots=1.8 TeV with the D0 detector at Fermilab's Tevatron Collider, we present the results of a search for direct pair production of scalar top quarks ((t) over bar), the supersymmetric partners of the top quark. We examined events containing two or more jets and missing transverse energy, the signature of light scalar top quark decays to charm quarks and neutralinos. After selections, we observe 27 events while expecting 31.1+/-6.4 events from known standard model processes. Comparing these results to next-to-leading-order production cross sections, we exclude a significant region of (t) over tilde and neutralino phase space. In particular, we exclude the (t) over tilde mass m((t) over tilde)<122 GeV/c(2) for a neutralino mass of 45 GeV/c(2).