Subjet Multiplicity in Quark and Gluon Jets at D0
arXiv:hep-ex/9907059 · doi:10.1016/S0920-5632(99)00764-1
Abstract
We measure the subjet multiplicity M in jets reconstructed with a successive combination type of jet algorithm (k_T). We select jets with 55<E_T<100 GeV and | η| < 0.5. We compare similar samples of jets at sqrt{s} = 1800 and 630 GeV. The HERWIG Monte Carlo simulation predicts that 59% of the jets are gluon jets at \sqrt{s} = 1800, and 33% at sqrt{s} = 630. Using this information, we extract the subjet multiplicity in quark (M_q) and gluon (M_g) jets. We also measure the ratio $R\equiv \frac{\left< M_{q}\right> -1}{% \left< M_{g}\right> -1}= 1.91 \pm 0.04{\rm(stat)} ^{+0.23}_{-0.19} {\rm(sys)}$.
9 pages, 3 figures, 1 table, contributed paper to EPS99 and Lepton-Photon99