LPC Physics Forum

Thursday 7 May 2026, 06:00 → 14:00 US/Central

Sunrise (WH11NW) (FNAL/Zoom)

https://cern.zoom.us/j/96898909340
contact lpc-pf@fnal.gov for the passcode

13:00 → 14:00 Direct observation of the dead-cone effect in b-quark initiated-jets from t-tbar decays

A measurement on the dead-cone effect in b-quark initiated jets with transverse momentum, pT, between 40 to 80 GeV and 80 to 200 GeV is presented. The measurement is performed with a proton-proton collision dataset collected by the CMS experiment at the LHC at sqrt(s)=13 TeV in 2018. The b-quark initiated jets are selected with a tag-and-probe technique in t-tbar events using the e-mu final state. The b-quark initiated jets are iteratively declustered to measure the transverse momentum, kT, and angular separation, delta R, of the soft emission relative to the hard emitter at each step. The dead-cone effect is probed directly by a measurement of the number of emissions per jet density distribution along delta R for ln(kT/GeV)>-1. The unfolded distributions, corrected for detector effects, are derived and compared to the predictions for b-quark initiated jets from various event generators with massive or massless splitting kernels in the parton shower models.

Speaker: Ka Wa Ho (Brown University (US))