TY - JOUR
T1 - Evidence for single top-quark production in the s-channel in proton–proton collisions at √s=8 TeV with the ATLAS detector using the Matrix Element Method
AU - ATLAS Collaboration
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 - Abulaiti, Y.
AU - Acharya, B. S.
AU - Adamczyk, L.
AU - Adams, D. L.
AU - Adelman, J.
AU - Adomeit, S.
AU - Adye, T.
AU - Affolder, A. A.
AU - Agatonovic-Jovin, T.
AU - Agricola, J.
AU - Aguilar-Saavedra, J. A.
AU - Ahlen, S. P.
AU - Ahmadov, F.
AU - Aielli, G.
AU - Akerstedt, H.
AU - Åkesson, T. P.A.
AU - Akimov, A. V.
AU - Alberghi, G. L.
AU - Albert, J.
AU - Albrand, S.
AU - Alconada Verzini, M. J.
AU - Aleksa, M.
AU - Aleksandrov, I. N.
AU - Alexa, C.
AU - Alexander, G.
AU - Alexopoulos, T.
AU - Alhroob, M.
AU - Alimonti, G.
AU - Alio, L.
AU - Alison, J.
AU - Alkire, S. P.
AU - Allbrooke, B. M.M.
AU - Allport, P. P.
AU - Aloisio, A.
AU - Alonso, A.
AU - Iizawa, T.
AU - Kimura, N.
AU - Mitani, T.
AU - Morinaga, M.
AU - Yorita, K.
N1 - Funding Information:
We acknowledge the support of ANPCyT , Argentina; YerPhI , Armenia; ARC , Australia; BMWFW and FWF , Austria; ANAS , Azerbaijan; SSTC , Belarus; CNPq and FAPESP , Brazil; NSERC , NRC and CFI , Canada; CERN ; CONICYT , Chile; CAS , MOST and NSFC , China; COLCIENCIAS , Colombia; MSMT CR , MPO CR and VSC CR , Czech Republic; DNRF , DNSRC and Lundbeck Foundation , Denmark; IN2P3-CNRS , CEA-DSM/IRFU , France; GNSF , Georgia; BMBF , HGF , and MPG , Germany; GSRT , Greece; RGC , Hong Kong SAR , China; ISF , I-CORE and Benoziyo Center , Israel; INFN , Italy; MEXT and JSPS , Japan; CNRST , Morocco; FOM and NWO , Netherlands; RCN , Norway; MNiSW and NCN , Poland; FCT , Portugal; MNE/IFA , Romania; MES of Russia and NRC KI , Russian Federation; JINR ; MESTD , Serbia; MSSR , Slovakia; ARRS and MIZŠ , Slovenia; DST/NRF , South Africa; MINECO , Spain; SRC and Wallenberg Foundation , Sweden; SERI , SNSF and Cantons of Bern and Geneva , Switzerland; MOST , Taiwan; TAEK , Turkey; STFC , United Kingdom; DOE and NSF , United States of America. In addition, individual groups and members have received support from BCKDF , the Canada Council , CANARIE , CRC , Compute Canada, FQRNT , and the Ontario Innovation Trust , Canada; EPLANET , ERC , FP7 , Horizon 2020 and Marie Skłodowska-Curie Actions , European Union; Investissements d'Avenir Labex and Idex , ANR , Region Auvergne and Fondation Partager le Savoir , France; DFG and AvH Foundation , Germany; Herakleitos , Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF ; BSF , GIF and Minerva , Israel; BRF , Norway; the Royal Society and Leverhulme Trust , United Kingdom.
Funding Information:
The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN and the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA) and in the Tier-2 facilities worldwide.
Publisher Copyright:
© 2016 CERN for the benefit of the ATLAS Collaboration
PY - 2016/5/10
Y1 - 2016/5/10
N2 - This Letter presents evidence for single top-quark production in the s-channel using proton–proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS detector at the CERN Large Hadron Collider. The analysis is performed on events containing one isolated electron or muon, large missing transverse momentum and exactly two b-tagged jets in the final state. The analysed data set corresponds to an integrated luminosity of 20.3 fb−1. The signal is extracted using a maximum-likelihood fit of a discriminant which is based on the matrix element method and optimized in order to separate single-top-quark s-channel events from the main background contributions, which are top-quark pair production and W boson production in association with heavy-flavour jets. The measurement leads to an observed signal significance of 3.2 standard deviations and a measured cross-section of σs=4.8±0.8(stat.)−1.3 +1.6(syst.) pb, which is consistent with the Standard Model expectation. The expected significance for the analysis is 3.9 standard deviations.
AB - This Letter presents evidence for single top-quark production in the s-channel using proton–proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS detector at the CERN Large Hadron Collider. The analysis is performed on events containing one isolated electron or muon, large missing transverse momentum and exactly two b-tagged jets in the final state. The analysed data set corresponds to an integrated luminosity of 20.3 fb−1. The signal is extracted using a maximum-likelihood fit of a discriminant which is based on the matrix element method and optimized in order to separate single-top-quark s-channel events from the main background contributions, which are top-quark pair production and W boson production in association with heavy-flavour jets. The measurement leads to an observed signal significance of 3.2 standard deviations and a measured cross-section of σs=4.8±0.8(stat.)−1.3 +1.6(syst.) pb, which is consistent with the Standard Model expectation. The expected significance for the analysis is 3.9 standard deviations.
UR - http://www.scopus.com/inward/record.url?scp=85042024827&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85042024827&partnerID=8YFLogxK
U2 - 10.1016/j.physletb.2016.03.017
DO - 10.1016/j.physletb.2016.03.017
M3 - Article
AN - SCOPUS:85042024827
SN - 0370-2693
VL - 756
SP - 228
EP - 246
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
ER -