Here, we present a search for the pair production of scalar top quarks ($\sim\atop{t}$1), the lightest supersymmetric partners of the top quarks, in $p\bar{p}$ collisions at a center-of-mass energy ...of 1.96 TeV, using data corresponding to an integrated luminosity of 7.3fb-1 collected with the D0 experiment at the Fermilab Tevatron Collider. Each scalar top quark is assumed to decay into a b quark, a charged lepton, and a scalar neutrino (ν˜). We investigate final states arising from$\sim\atop{t}$1 $≂\atop{t}$1→$b\bar{b}$ μτ$\sim\atop{v}$$\sim\atop{v}$ and $\sim\atop{t}$1$≂\atop{t}$1→$b\bar{b}$ ττ$\sim\atop{v}$$\sim\atop{v}$. With no significant excess of events observed above the background expected from the standard model, we set exclusion limits on this production process in the (m$\sim\atop{t}$1, m$\sim\atop{v}$) plane.
We report results from searches for neutral Higgs bosons produced in pp¯ collisions recorded by the D0 experiment at the Fermilab Tevatron Collider. We study the production of inclusive neutral Higgs ...boson in the ττ final state and in association with a b quark in the bττ and bbb final states. These results are combined to improve the sensitivity to the production of neutral Higgs bosons in the context of the minimal supersymmetric standard model (MSSM). The data are found to be consistent with expectation from background processes. Upper limits on MSSM Higgs boson production are set for Higgs boson masses ranging from 90 to 300 GeV. We exclude tanβ>20–30 for Higgs boson masses below 180 GeV. These are the most stringent constraints on MSSM Higgs boson production in pp¯ collisions.
We present a search for pair production of doubly charged Higgs bosons in the processes q¯q→H++H−− decaying through H±±→τ±τ±,μ±τ±,μ±μ±. The search is performed in p¯p collisions at a center-of-mass ...energy of √s=1.96 TeV using an integrated luminosity of up to 7.0 fb−1 collected by the D0 experiment at the Fermilab Tevatron Collider. The results are used to set 95% C.L. limits on the pair production cross section of doubly charged Higgs bosons and on their mass for different H±± branching fractions. Models predicting different H±± decays are investigated. Assuming B(H±±→τ±τ±)=1 yields an observed (expected) lower limit on the mass of a left-handed H±±L boson of 128 (116) GeV and assuming B(H±±→μ±τ±)=1 the corresponding limits are 144 (149) GeV. In a model with B(H±±→τ±τ±)=B(H±±→μ±τ±)=B(H±±→μ±μ±)=1/3, we obtain M(H±±L)>130 (138) GeV.
We measure the cross section and the difference in rapidities between photons and charged leptons for inclusive W(→lν)+γ production in eγ and μγ final states. Using data corresponding to an ...integrated luminosity of 4.2 fb⁻¹ collected with the D0 detector at the Fermilab Tevatron Collider, the measured cross section times branching fraction for the process pp̄→Wγ+X→lνγ+X and the distribution of the charge-signed photon-lepton rapidity difference are found to be in agreement with the standard model. These results provide the most stringent limits on anomalous WWγ couplings for data from hadron colliders: -0.4<Δκγ<0.4 and -0.08<λγ<0.07 at the 95% C.L.
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