549 documents found, page 1 of 55
A template method to measure the tt¯ polarisation
Aguilar-Saavedra, J.A.; Fiolhais, M. C. N.; Martín-Ramiro, P.; Moreno, J. M.; Onofre, A.We develop a template method for the measurement of the polarisation of t ¯t pairs produced in hadron collisions. The method would allow to extract the individual fractions of tL ¯tL , tR ¯tR, tL ¯tR and tR ¯tL pairs with a fit to data, where L, R refer to the polarisation along any axis. These polarisation fractions have not been independently measured at present. Secondarily, the method also provides the net ...
Measurement of the c-jet mistagging efficiency in tt¯ events using pp collision...
Castro, N. F.; Fiolhais, M. C. N.; Gonçalo, J. R.; Onofre, A.; Veloso, F.; Wolters, H.; Atlas CollaborationA technique is presented to measure the efficiency with which c-jets are mistagged as b-jets (mistagging efficiency) using t ¯t events, where one of theW bosons decays into an electron or muon and a neutrino and the other decays into a quark–antiquark pair. The measurement utilises the relatively large and known W → cs branching ratio, which allows ameasurement to be made in an inclusive c-jet sample. The data ...
Erratum to: Search for single top-quark production via flavour-changing neutral...
Santos, S. P. Amor dos; Carvalho, J.; Fiolhais, M. C. N.; Galhardo, B.; Onofre, A.; Veloso, F.; Wolters, H.; Atlas Collaboration
Performance of the ATLAS Level-1 topological trigger in Run 2
Fiolhais, M. C. N.; Gonçalo, J. R.; Onofre, A.; Veloso, F.; Wolters, H.; Atlas Collaboration
Search for flavour-changing neutral-current interactions of a top quark and a g...
Fiolhais, M. C. N.; Gonçalo, R.; Veloso, F.; Wolters, H.; Atlas Colaboration; et al.A search is presented for the production of a single top quark via left-handed flavour-changing neutral-current (FCNC) interactions of a top quark, a gluon and an up or charm quark. Two production processes are considered: u+ g→ t and c+ g→ t. The analysis is based on proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. The data set corresponds to an integr...
A template method to measure the t(t)over-bar polarisation
Aguilar-Saavedra, J. A.; Fiolhais, M. C. N.; Martin-Ramiro, P.; Moreno, J. M.; Onofre, A.We develop a template method for the measurement of the polarisation of t (t) over bar pairs produced in hadron collisions. The method would allow to extract the individual fractions of t(L)(t) over bar (L), t(R)(t) over bar (R), t(L)(t) over bar (R) and t(R)(t) over bar (L) pairs with a fit to data, where L, R refer to the polarisation along any axis. These polarisation fractions have not been independently me...
Search for exotic decays of the Higgs boson into $b\bar{b}$ and missing transve...
Fiolhais, M. C. N.; Gonçalo, J. R.; Wolters, H.; Veloso, F.; ATLAS CollaborationComments: 38 pages in total, author list starting on page 22, 4 figures, 2 tables, published in JHEP. All figures, including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HDBS-2018-07/; A search for the exotic decay of the Higgs boson ($H$) into a $b\bar{b}$ resonance plus missing transverse momentum is described. The search is performed with the ATLAS detector at the L...
Search for charged Higgs bosons decaying into a top quark and a bottom quark at...
Fiolhais, M. C. N.; Veloso, F.; Wolters, H.; Gonçalo, R.; Atlas CollaborationA search for charged Higgs bosons decaying into a top quark and a bottom quark is presented. The data analysed correspond to 139 fb−1 of proton-proton collisions at p s = 13TeV, recorded with the ATLAS detector at the LHC. The production of a heavy charged Higgs boson in association with a top quark and a bottom quark, pp ! tbH+ ! tbtb, is explored in the H+ mass range from 200 to 2000 GeV using final states wi...
Search for squarks and gluinos in final states with jets and missing transverse...
Fiolhais, M. C. N.; Gonçalo, R.; Veloso, F.; Wolters, H.; ATLAS CollaborationA search for the supersymmetric partners of quarks and gluons (squarks and gluinos) in final states containing jets and missing transverse momentum, but no electrons or muons, is presented. The data used in this search were recorded by the ATLAS experiment in proton-proton collisions at a centre-of-mass energy of p s = 13TeV during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of...
Search for new phenomena in events with two opposite-charge leptons, jets and m...
Fiolhais, M. C. N.; Gonçalo, R.; Veloso, F.; Wolters, H.; ATLAS CollaborationThe results of a search for direct pair production of top squarks and for dark matter in events with two opposite-charge leptons (electrons or muons), jets and missing transverse momentum are reported, using 139 fb−1 of integrated luminosity from protonproton collisions at p s = 13TeV, collected by the ATLAS detector at the Large Hadron Collider during Run 2 (2015–2018). This search considers the pair productio...