DPG Phi
Verhandlungen
Verhandlungen
DPG

Aachen 2019 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

T: Fachverband Teilchenphysik

T 82: Flavor-Tagging, Jet-Kalibration

T 82.5: Talk

Thursday, March 28, 2019, 17:00–17:15, S09

Double-b-tagging calibration in gbb events with the ATLAS experiment — •Ruth Jacobs, Tatjana Lenz, and Norbert Wermes — Physikalisches Institut, Universität Bonn

In 2018, the ATLAS and CMS collaborations announced the discovery of the Higgs boson decay into two b-quarks with the main contribution from the vector boson associated production mode. To access other production modes, such as gluon gluon fusion, in connection with the Hbb decay, it is useful to consider Higgs bosons with a large transverse momentum, as the relative background contribution is reduced in this kinematic regime. In boosted Hbb decays, the b-quark fragmentation products are reconstructed using a single large-R jet. A Higgs boson identification algorithm ("Higgs tagging") can be used to decide whether a jet originated from a Higgs boson decay, based on the large-R jet properties. One of the main ingredients for Higgs tagging is the determination of the flavour content of the candidate large-R jet. This is achieved by the so-called double-b-tagging method where a b-jet identification ("b-tagging") algorithm is used on two small-R sub-jets associated to the large-R jet. Since b-tagging algorithms are optimized on simulated events only, they must be calibrated in data. In order to calibrate double-b-tagging directly, a data sample of close-by b-jet events is needed. One possibility is to use data events of gluons splitting into b-quark pairs, which are produced abundantly at the LHC. In my talk I will present the strategy and results of the first direct double-b-tagging calibration in gbb events with the ATLAS experiment using data collected at the LHC in 2015 and 2016.

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2019 > Aachen