Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 0707.1550

Search for Single Top Quark Production Using Likelihood Discriminants at D0 in Run II

S. Jabeen
View original source ↗Read source document ↗Export metadata ↓

Abstract

We present an improved search for single top quarks in two production modes, s-channel (tb) and t-channel (tqb). The search is performed in the electron+jets and muon+jets decay channels, with one or more b-tagged jets, on nearly 370 pb^{-1} of D0 Run II data collected between August 2002 and October 2004. Impact-parameter based b-quark tagging is used to select signal-like events. We use a likelihood discriminant method to separate signals from backgrounds. The resulting expected/observed 95% confidence level upper limits on the single top quark production cross sections are 3.3/5.0pb (s-channel) and 4.3/4.4pb (t-channel).

Explore related subjects

hep-ex

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S. Jabeen. 2007-07-11. Search for Single Top Quark Production Using Likelihood Discriminants at D0 in Run II. https://arxiv.org/abs/0707.1550

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Study of ZZ and ZH production in the bb$ττ$ final state and search for high-mass spin-0 and spin-1 resonances in proton-proton collisions at $\sqrt{s}$ = 13 TeV

A study of the production of pairs of Z bosons (ZZ) and of the associated production of a Z boson and a Higgs boson (ZH) in final states containing two b quarks and two tau leptons (bb$ττ$) is presented. The analysis is based on proton-proton collisions collected at $\sqrt{s}$ = 13 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb$^{-1}$. The nonresonant analysis targets the standard model ZZ and ZH processes in the bb$ττ$ final state, motivated by the prominent role of this channel in searches for nonresonant Higgs boson pair production. The resonant searches target physics beyond the standard model, probing heavy spin-0 resonances X that decay into ZZ and spin-1 resonances Z' that decay into ZH, with masses in the 0.2$-$5 and 0.5$-$6 TeV ranges, respectively. Upper limits at 95% confidence level are set on the product of production rate and branching fraction $σ$(X)$\mathcal{B}$(X $\to$ ZZ), ranging from 300 pb to 24 fb, and $σ$(Z')$\mathcal{B}$(Z' $\to$ ZH), ranging from 0.4 pb to 12 fb. These are the first measurements to probe the ZZ/ZH $\to$ bb$ττ$ processes. No deviation from standard model expectations is observed.

hep-ex↗
arXiv2026

Search for nonresonant triple Higgs boson production in the final state with six bottom quarks in proton-proton collisions at $\sqrt{s}$ = 13 TeV

A search for nonresonant triple Higgs boson (HHH) production in the final state with six bottom quarks is performed using proton-proton collisions at $\sqrt{s}$ = 13 TeV corresponding to an integrated luminosity of 138 fb$^{-1}$ recorded by the CMS experiment. No significant excess of events over the background prediction is seen. Observed (expected) 95% confidence level upper limits on the signal cross section are set at 44 (43) fb, corresponding to 588 (572) times the standard model expectation. The observed (expected) constraint on the trilinear coupling modifier $κ_3$ is $-$7.4 $\lt$ $κ_3$ $\lt$ 12.4 ($-$6.4 $\lt$ κ_3 $\lt$ 11.2), assuming the quartic coupling modifier $κ_4$ = 1. The corresponding constraint on $κ_4$ is $-$177 $\lt$ $κ_4$ $\lt$ 185 ($-$180 $\lt$ $κ_4$ $\lt$ 190), assuming $κ_3$ = 1. This analysis provides the most stringent constraint to date on nonresonant HHH production and excludes, for the first time, part of the $(κ_3,κ_4)$ space allowed by the perturbative unitarity bound.

hep-ex↗
arXiv2026

Search for soft unclustered energy patterns in proton-proton collisions at $\sqrt{s}$ = 13 TeV using data scouting

A search for soft unclustered energy patterns (SUEPs) is conducted using proton-proton collision data corresponding to an integrated luminosity of 127 fb$^{-1}$ at a center-of-mass energy of 13 TeV, collected via the data scouting stream of the CMS experiment at the LHC. Only the results of the high-level trigger reconstruction are recorded to enable a lower threshold on the hadronic activity. This increases the acceptance for SUEP signatures, which are predicted by hidden-valley models with a large 't Hooft coupling. The observed results are consistent with the standard model background prediction. The most stringent limits to date are set on the gluon fusion production of heavy scalar mediators resulting in SUEP-like signals.

hep-ex↗