4 documents found, page 1 of 1
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 ...
Identification of boosted Higgs bosons decaying into b-quark pairs with the ATL...
Fiolhais, M. C. N.; Veloso, F.; Wolters, H.; Aguilar-Saavedra, J.A.; Santos, S. P. Amor dos; Araque, J. P.; Castro, N. F.; Muiño, P. CondeThis paper describes a study of techniques for identifying Higgs bosons at high transverse momenta decaying into bottom-quark pairs, H→ bb¯ , for proton–proton collision data collected by the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy s=13 TeV. These decays are reconstructed from calorimeter jets found with the anti-ktR= 1.0 jet algorithm. To tag Higgs bosons, a combination of requir...
ATLAS sensitivity to Wtb anomalous couplings in top quark decays
Aguilar-Saavedra, J.A.; Carvalho, J.; Castro, N.; Onofre, A.; Veloso, F.Abstract We study the sensitivity of the ATLAS experiment to Wtb anomalous couplings in top pair production with semileptonic decay, pp?tt̄?W+bW-b̄ with one of the W bosons decaying leptonically and the other hadronically. Several observables are examined, including the W helicity fractions and new quantities recently introduced, such as the ratios of helicity fractions and some angular asymmetries de...
Probing anomalous Wtb couplings in top pair decays
Aguilar-Saavedra, J.A.; Carvalho, J.; Castro, N.; Onofre, A.; Veloso, F.Abstract We investigate several quantities, defined in the decays of top quark pairs, which can be used to explore non-standard Wtb interactions. Two new angular asymmetries are introduced in the leptonic decay of top (anti)quarks. Both are very sensitive to anomalous Wtb couplings, and their measurement allows for a precise determination of the W helicity fractions. We also examine other angular and energy asy...