Study of jet shapes in inclusive jet production in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$

We report on a study of jet shapes in inclusive jet production in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ using the upgraded collider detector at Fermilab in Run II (CDF II) and based on an integrated luminosity of $170\mathrm{p}{\mathrm{b}}^{-1}$. Measurements are carried out on jets with rapidity $0.1<|Y^{\mathrm{jet}}|<0.7$ and transverse momentum $37\mathrm{GeV}/c<P_T^{\mathrm{jet}}<380\mathrm{GeV}/c$. The jets have been corrected to the hadron level. The measured jet shapes are compared to leading-order QCD parton-shower Monte Carlo predictions as implemented in the PYTHIA and HERWIG programs. PYTHIA, tuned to describe the underlying event as measured in CDF Run I, provides a better description of the measured jet shapes than does PYTHIA or HERWIG with their default parameters.

Figure 1

Longitudinal view of half of the CDF II detector.

Figure 2

The measured differential jet shape, $\rho (r/R)$, in inclusive jet production for jets with $0.1<|Y^{\mathrm{jet}}|<0.7$ and $37\mathrm{GeV}/c<P_T^{\mathrm{jet}}<148\mathrm{GeV}/c$, is shown in different $P_T^{\mathrm{jet}}$ regions. Error bars indicate the statistical and systematic uncertainties added in quadrature. The predictions of PYTHIA-Tune A (solid lines) and HERWIG (dashed lines) are shown for comparison.

Figure 3

The measured differential jet shape, $\rho (r/R)$, in inclusive jet production for jets with $0.1<|Y^{\mathrm{jet}}|<0.7$ and $148\mathrm{GeV}/c<P_T^{\mathrm{jet}}<380\mathrm{GeV}/c$, is shown in different $P_T^{\mathrm{jet}}$ regions. Error bars indicate the statistical and systematic uncertainties added in quadrature. The predictions of PYTHIA-Tune A (solid lines) and HERWIG (dashed lines) are shown for comparison.

Figure 4

The measured integrated jet shape, $\Psi (r/R)$, in inclusive jet production for jets with $0.1<|Y^{\mathrm{jet}}|<0.7$ and $37\mathrm{GeV}/c<P_T^{\mathrm{jet}}<148\mathrm{GeV}/c$, is shown in different $P_T^{\mathrm{jet}}$ regions. Error bars indicate the statistical and systematic uncertainties added in quadrature. The predictions of PYTHIA-Tune A (solid lines), PYTHIA (dashed-dotted lines), PYTHIA-(no MPI) (dotted lines) and HERWIG (dashed lines) are shown for comparison.

Figure 5

The measured integrated jet shape, $\Psi (r/R)$, in inclusive jet production for jets with $0.1<|Y^{\mathrm{jet}}|<0.7$ and $148\mathrm{GeV}/c<P_T^{\mathrm{jet}}<380\mathrm{GeV}/c$, is shown in different $P_T^{\mathrm{jet}}$ regions. Error bars indicate the statistical and systematic uncertainties added in quadrature. The predictions of PYTHIA-Tune A (solid lines), PYTHIA (dashed-dotted lines), PYTHIA-(no MPI) (dotted lines) and HERWIG (dashed lines) are shown for comparison.

Figure 6

The measured $1-\Psi (0.3/R)$ as a function of $P_T^{\mathrm{jet}}$ for jets with $0.1<|Y^{\mathrm{jet}}|<0.7$ and $37\mathrm{GeV}/c<P_T^{\mathrm{jet}}<380\mathrm{GeV}/c$. Error bars indicate the statistical and systematic uncertainties added in quadrature. The predictions of PYTHIA-Tune A (solid line), PYTHIA (dashed-dotted line), PYTHIA-(no MPI) (dotted line) and HERWIG (dashed line) are shown for comparison.

Figure 7

The measured integrated jet shape, $\Psi (r/R)$, in inclusive jet production for jets with $0.1<|Y^{\mathrm{jet}}|<0.7$ and $37\mathrm{GeV}/c<P_T^{\mathrm{jet}}<148\mathrm{GeV}/c$, is shown in different $P_T^{\mathrm{jet}}$ regions. Error bars indicate the statistical and systematic uncertainties added in quadrature. The predictions of PYTHIA-Tune A (solid lines) and the separate predictions for quark-initiated jets (dotted lines) and gluon-initiated jets (dashed lines) are shown for comparison.

Figure 8

The measured integrated jet shape, $\Psi (r/R)$, in inclusive jet production for jets with $0.1<|Y^{\mathrm{jet}}|<0.7$ and $148\mathrm{GeV}/c<P_T^{\mathrm{jet}}<380\mathrm{GeV}/c$, is shown in different $P_T^{\mathrm{jet}}$ regions. Error bars indicate the statistical and systematic uncertainties added in quadrature. The predictions of PYTHIA-Tune A (solid lines) and the separate predictions for quark-initiated jets (dotted lines) and gluon-initiated jets (dashed lines) are shown for comparison.

Figure 9

The measured $1-\Psi (0.3/R)$ as a function of $P_T^{\mathrm{jet}}$ for jets with $0.1<|Y^{\mathrm{jet}}|<0.7$ and $37\mathrm{GeV}/c<P_T^{\mathrm{jet}}<380\mathrm{GeV}/c$. Error bars indicate the statistical and systematic uncertainties added in quadrature. The predictions of PYTHIA-Tune A (solid line) and the separate predictions for quark-initiated jets (dotted line) and gluon-initiated jets (dashed line) are shown for comparison. The arrows indicate the fraction of quark- and gluon-initiated jets at low and very high $P_T^{\mathrm{jet}}$, as predicted by PYTHIA-Tune A.