Implementation And Calibration Of A K Durham Algorithm Jet Finding Algorithm For Use In Pp U02c9 Collisions At Square Root Of S

Implementation and Calibration of a K [Durham Algorithm] Jet Finding Algorithm for Use in Pp{u02C9} Collisions at [square Root Of] S

ATLAS B-jet Identification Performance and Efficiency Measurement with Tt[over-bar] Events in Pp Collisions at [square Root]s

Abstract: The algorithms used by the ATLAS Collaboration during Run 2 of the Large Hadron Collider to identify jets containing b-hadrons are presented. The performance of the algorithms is evaluated in the simulation and the efficiency with which these algorithms identify jets containing b-hadrons is measured in collision data. The measurement uses a likelihood-based method in a sample highly enriched in tt ̄ events. The topology of the t→Wb decays is exploited to simultaneously measure both the jet flavour composition of the sample and the efficiency in a transverse momentum range from 20 to 600 GeV. The efficiency measurement is subsequently compared with that predicted by the simulation. The data used in this measurement, corresponding to a total integrated luminosity of 80.5 fb−1, were collected in proton-proton collisions during the years 2015-2017 at a centre-of-mass energy s√= 13 TeV. By simultaneously extracting both the efficiency and jet flavour composition, this measurement significantly improves the precision compared to previous results, with uncertainties ranging from 1 to 8% depending on the jet transverse momentum

Jet Measurements at D0 Using a KT Algorithm

D0 has implemented and calibrated a k[perpendicular] jet algorithm for the first time in a p[bar p] collider. We present two results based on 1992-1996 data which were recently published: the subjet multiplicity in quark and gluon jets and the central inclusive jet cross section. The measured ratio between subjet multiplicities in gluon and quark jets is consistent with theoretical predictions and previous experimental values. NLO pQCD predictions of the k[perpendicular] inclusive jet cross section agree with the D0 measurement, although marginally in the low p[sub T] range. We also present a preliminary measurement of thrust cross sections, which indicates the need to include higher than[alpha][sub s][sup 3] terms and resumation in the theoretical calculations.