TY - JOUR
T1 - Measurements of fiducial cross-sections for t(t)over-bar production with one or two additional b-jets in pp collisions at root s=8 TeV using the ATLAS detector
AU - Aad, G.
AU - Abbott, B.
AU - Abdallah, J.
AU - Abdinov, O.
AU - Aben, R.
AU - Abolins, M.
AU - AbouZeid, O.S.
AU - Abramowicz, H.
AU - Abreu, H.
AU - Abreu, R.
AU - Acharya, B.S.
AU - Adamczyk, L.
AU - Adams, David L.
AU - Dam, Mogens
AU - Hansen, Jørn Dines
AU - Hansen, Jørgen Beck
AU - Xella, Stefania
AU - Hansen, Peter Henrik
AU - Petersen, Troels Christian
AU - Thomsen, Lotte Ansgaard
AU - Pingel, Almut Maria
AU - Løvschall-Jensen, Ask Emil
AU - Alonso Diaz, Alejandro
AU - Monk, James William
AU - Pedersen, Lars Egholm
AU - Wiglesworth, Graig
AU - Galster, Gorm Aske Gram Krohn
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Fiducial cross-sections for tt¯ production with one or two additional b-jets are reported, using an integrated luminosity of 20.3 fb-1 of proton–proton collisions at a centre-of-mass energy of 8 TeV at the Large Hadron Collider, collected with the ATLAS detector. The cross-section times branching ratio for tt¯ events with at least one additional b-jet is measured to be 950 ± 70 (stat.) -190 +240 (syst.) fb in the lepton-plus-jets channel and 50 ± 10 (stat.) -10 +15 (syst.) fb in the eμ channel. The cross-section times branching ratio for events with at least two additional b-jets is measured to be 19.3 ± 3.5 (stat.) ± 5.7 (syst.) fb in the dilepton channel (eμ, μμ, and ee) using a method based on tight selection criteria, and 13.5 ± 3.3 (stat.) ± 3.6 (syst.) fb using a looser selection that allows the background normalisation to be extracted from data. The latter method also measures a value of 1.30 ± 0.33 (stat.) ± 0.28 (syst.)% for the ratio of tt¯ production with two additional b-jets to tt¯ production with any two additional jets. All measurements are in good agreement with recent theory predictions.
AB - Fiducial cross-sections for tt¯ production with one or two additional b-jets are reported, using an integrated luminosity of 20.3 fb-1 of proton–proton collisions at a centre-of-mass energy of 8 TeV at the Large Hadron Collider, collected with the ATLAS detector. The cross-section times branching ratio for tt¯ events with at least one additional b-jet is measured to be 950 ± 70 (stat.) -190 +240 (syst.) fb in the lepton-plus-jets channel and 50 ± 10 (stat.) -10 +15 (syst.) fb in the eμ channel. The cross-section times branching ratio for events with at least two additional b-jets is measured to be 19.3 ± 3.5 (stat.) ± 5.7 (syst.) fb in the dilepton channel (eμ, μμ, and ee) using a method based on tight selection criteria, and 13.5 ± 3.3 (stat.) ± 3.6 (syst.) fb using a looser selection that allows the background normalisation to be extracted from data. The latter method also measures a value of 1.30 ± 0.33 (stat.) ± 0.28 (syst.)% for the ratio of tt¯ production with two additional b-jets to tt¯ production with any two additional jets. All measurements are in good agreement with recent theory predictions.
U2 - 10.1140/epjc/s10052-015-3852-4
DO - 10.1140/epjc/s10052-015-3852-4
M3 - Journal article
C2 - 26770069
SN - 1434-6044
VL - 76
JO - European Physical Journal C
JF - European Physical Journal C
IS - 1
M1 - 11
ER -