Speaker
Description
The suppression of collinear gluon emissions from a massive quark, or the “dead- cone effect,” is the primary manifestation of quark mass effects in parton showers. A differential measurement is presented of the emission density of bottom quarks, studied as a function of the angular separation between the emissions from the same emitter. The measurement is performed in bottom quark-initiated jets with transverse momenta between 40 and 200 GeV originating from top quark and top antiquark production. A proton-proton collision data set recorded by the CMS experiment at √s = 13 TeV with an integrated luminosity of 59.8 fb$^{−1}$ is analyzed. The measurement of the emission density of bottom quarks strongly favors parton shower models that include the dead-cone effect.