相关论文: Hadron multiplicity as the limit of jet multiplici…
The perturbative QCD approach to multiparticle production predicts a characteristic suppression of particle multiplicity in a heavy quark jet as compared to a light quark jet. In the Modified Leading Logarithmic Approximation (MLLA) the…
Recent results on QCD studies in e+e- annihilations at LEP are presented. Data recorded by the LEP experiments at centre-of-mass energies between 91.2 to 206 GeV are included. The main topic is the measurement of alpha_s from event-shape…
Hadronic final states in hadron-hadron collisions are often studied by clustering final state hadrons into jets, each jet approximately corresponding to a hard parton. The typical jet size in a high energy hadron collision is between 0.4…
Ultra-relativistic heavy ion collisions at RHIC and the LHC open exciting new possibilities for jet physics studies in the presence of hot and dense nuclear matter. Recent theoretical advances in understanding the QCD multi-parton dynamics…
The subjet multiplicity has been measured in neutral current e+p interactions at Q**2 > 125 GeV**2 with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb-1. Jets were identified in the laboratory frame using the…
The status of determinations of the QCD coupling constant, alphas, at HERA is reviewed. Since jet final states provide the most relevant input to the HERA determinations of alphas, the relevant methods used in and results from jet physics…
We will offer the formal arguments that the very high multiplicity (VHM) events are defined by the heavy QCD jets and, with exponential over multiplicity accuracy, the number of jets must decrease with the increasing multiplicity. This must…
We review recent developments in the calculation of QCD loop amplitudes with several external legs, and their application to next-to-leading order jet production cross-sections. When a number of calculational tools are combined together ---…
We report the evolution effects on jet energy loss with detailed balance. The initial conditions and parton evolution based on perturbative QCD in the chemical non-equilibrated medium and Bjorken expanding medium at RHIC are determined. The…
We discuss non-perturbative QCD contributions to jet observables, computing their dependence on the jet radius R, and on the colour and transverse momentum of the parton initiating the jet. We show, using analytic QCD models of power…
The complete QCD evolution equation for factorial moments in quark and gluon jets is numerically solved with initial conditions at threshold by fully taking into account the energy-momentum conservation law. Within the picture of Local…
We calculate the rate for $e^+e^-$ annihilation into four jets at next-to-leading order in perturbative QCD, but omitting terms that are suppressed by one or more powers of $1/\Nc^2$, where $\Nc$ is the number of colors. The…
I examine the determination of the QCD color factor ratio CA/CF from the scale evolution of particle multiplicity in e+e- three jet events. I fit an analytic expression for the multiplicity in three jet events to event samples generated…
We discuss the recent claim that hadron multiplicities measured at RHIC energies are directly described in terms of gluon degrees of freedom fixed from the initial conditions of central heavy ion collisions. The argument is based on the…
We compute the nonleptonic weak decay width of a heavy-light meson in 1+1 spacetime dimensions with a large number of QCD colors (the 't Hooft model) as a function of the heavy quark mass. In this limit, QCD is exactly soluble, and decay…
In this paper, we present a more detailed version of our previous work for three-particle correlations in quark and gluon jets [1]. We give theoretical results for this observable in the double logarithmic approximation and the modified…
Hadron multiplicities of $\pim$, $\pip$, $\km$ and $\kp$ have been measured in the deep-inelastic scattering of 27.5 GeV positrons off a hydrogen target. The data used in this analysis have been collected during the 2000 HERA running…
We compute the average Lund multiplicity of high-energy QCD jets. This extends an earlier calculation, done for event-wide multiplicity in $e^+e^-$ collisions [arxiv:2205.02861], to the large energy range available at the LHC. Our…
We discuss the theory of jet events in high-energy photon-proton interactions using a model which gives a good description of the data available on total inelastic $\gamma p$ cross sections up to $\sqrt{s}$=210 GeV. We show how to calculate…
The energy evolution of average multiplicities of quark and gluon jets is studied in perturbative QCD. Higher order (3NLO) terms in the perturbative expansion of equations for the generating functions are found. First and second derivatives…