Measurements of jet observables sensitive to b -quark fragmentation in t t ¯ events at the LHC with the ATLAS detector

Summary, in English

Several observables sensitive to the fragmentation of b quarks into b hadrons are measured using 36 fb-1 of s=13 TeV proton-proton collision data collected with the ATLAS detector at the LHC. Jets containing b hadrons are obtained from a sample of dileptonic tt¯ events, and the associated set of charged-particle tracks is separated into those from the primary pp interaction vertex and those from the displaced b-decay secondary vertex. This division is used to construct observables that characterize the longitudinal and transverse momentum distributions of the b hadron within the jet. The measurements have been corrected for detector effects and provide a test of heavy-quark-fragmentation modeling at the LHC in a system where the top-quark decay products are color connected to the proton beam remnants. The unfolded distributions are compared with the predictions of several modern Monte Carlo parton-shower generators and generator tunes, and a wide range of agreement with the data is observed, with p values varying from 5×10-4 to 0.98. These measurements complement similar measurements from e+e- collider experiments in which the b quarks originate from a color singlet Z/γ∗. © 2022 CERN.

• Author: G. Aad; T.P.A. Åkesson; S.S. Bocchetta; E.E. Corrigan; C. Doglioni; J. Geisen; K. Gregersen; E. Hansen; V. Hedberg; G. Jarlskog; E. Kellermann; B. Konya; E. Lytken; K.H. Mankinen; C. Marcon; J.U. Mjörnmark; G.A. Mullier; R. Poettgen; T. Poulsen; E. Skorda; O. Smirnova; L. Zwalinski
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2022
• Language: English
• Publication/Series: Physical Review D
• Volume: 106
• Issue: 3
• Links: http://dx.doi.org/10.1103/PhysRevD.106.032008
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 2470-0010