Measurement of $t$-channel single-top-quark production in $pp$ collisions at $\sqrt{s}=5.02$ TeV with the ATLAS detector

Abstract

The observation of the electroweak production of single-top-quarks is made using 255 ${\text{pb}}^{-1}$ of proton-proton collision data recorded at $\sqrt{s}=5.02$ TeV with the ATLAS detector at the Large Hadron Collider. An event selection is used to identify single-top-quark candidates arising from $t$-channel production with the top quark decaying semi-leptonically. Events passing the selection are then used to measure the inclusive cross-section for the combined production of single-top-quarks and antiquarks, $\sigma (tq+\bar{t}q)$, and the ratio $R_t$ between these two. They are measured to be $\sigma (tq+\bar{t}q)=27.1_{-4.1}^{+4.4}(\text{stat.}{)}_{-3.7}^{+4.4}(\text{syst.})$ pb and $R_t=2.73_{-0.82}^{+1.43}(\text{stat.}{)}_{-0.29}^{+1.01}(\text{syst.})$. The individual single-top-quark ($tq$) and single-top-antiquark ($\bar{t}q$) production cross-sections are measured to be $\sigma (tq)=19.8_{-3.1}^{+3.9}(\text{stat.}{)}_{-2.2}^{+2.9}(\text{syst.})$ pb and $\sigma (\bar{t}q)=7.3_{-2.1}^{+3.2}(\text{stat.}{)}_{-1.5}^{+2.8}(\text{syst.})$ pb. All measurements are in good agreement with the Standard Model predictions.

33 pages in total, author list starting on page 16, 4 figures and 2 tables. The missing acknowledgements have been added in v3. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2022-22/

References in corpus (10)

• New parton distributions for collider physics
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• MCFM for the Tevatron and the LHC
• HATHOR for single top-quark production: Updated predictions and uncertainty estimates for single top-quark production in hadronic collisions
• Muon reconstruction and identification efficiency in ATLAS using the full Run 2 $pp$ collision data set at $\sqrt{s}=13$ TeV
• Jet energy scale and resolution measured in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Performance of the ATLAS muon triggers in Run 2
• Next-to-leading-order predictions for t-channel single-top production at hadron colliders
• ATLAS flavour-tagging algorithms for the LHC Run 2 $pp$ collision dataset
• Testing parton distribution functions with t-channel single-top-quark production

Cited by in corpus (1)

• Inclusive top cross sections in ATLAS