Measurement ofb-jet shapes in inclusive jet production inpp¯collisions ats=1.96TeV

We present a measurement of the shapes of $b$-jets using $300{\mathrm{pb}}^{-1}$ of data obtained with the upgraded Collider Detector at Fermilab (CDF II) in $p\overline{p}$ collisions at center-of-mass energy $\sqrt{s}=1.96\mathrm{TeV}$. This measurement covers a wide transverse momentum range, from 52 to $300\mathrm{GeV}/c$. Samples of heavy-flavor enhanced jets together with inclusive jets are used to extract the average shapes of $b$-jets. The $b$-jets are expected to be broader than inclusive jets. Moreover, $b$-jets containing a single $b$-quark are expected to be narrower than those containing a $b\overline{b}$ pair from gluon splitting. The measured $b$-jet shapes are found to be significantly broader than expected from the pythia and herwig Monte Carlo simulations. This effect may arise from an underestimation of the fraction of $b$-jets originating from gluon splitting in these simulations. The jet shape distributions provided in this paper could be compared to any full Monte Carlo simulation and could be used to further constrain the various parameters.