相关论文: Multijet Final States in e+e- Annihilation

Copious production of very energetic jets is expected at the LHC due to the large increase in collision energy. Jet reconstruction at these high center of mass energies will provide crucial leverage to map out the QCD evolution of parton…

We consider the process of annihilation of e^+ e^- to three pion final state for the case of moderately high energies. The final state emission of virtual and real photon is considered explicitly. The calculations are performed in frames of…

A summary is given of some recent QCD results from LEP. For LEP-2, the topics include event shape measurements, determinations of the strong coupling constant, and measurements of the charged particle multiplicity distribution at the…

A search is presented for excited quarks of light and heavy flavor that decay to $\gamma$+jet final states. The analysis is based on data corresponding to an integrated luminosity of 35.9 fb$^{-1}$ collected by the CMS experiment in…

We report on the calculation of NNLO corrections to the 3-jet cross section and related event shape distributions in electron-positron annihilation. The corrections are sizable for all variables, however the magnitude of the corrections is…

We present a measurement of the strong coupling alpha_S using the three-jet rate measured with the Durham algorithm in e+e- -annihilation using data of the JADE experiment at centre-of-mass energies between 14 and 44 GeV. Recent theoretical…

We report measurements of the observed cross sections for $e^+e^-\to\omega \pi^+\pi^-$, $\omega K^+K^-$, $\omega p\bar p$, $K^+K^-\rho^0\pi^0$, $K^+K^-\rho^+\pi^-+c.c.$, $K^{*0}K^-\pi^+\pi^0+c.c.$, $K^{*+}K^-\pi^+\pi^-+c.c.$,…

The structure of e+e- -> bbg events was studied using Z0 decays recorded in the SLD experiment at SLAC. Three-jet final states were selected and the CCD-based vertex detector was used to identify two of the jets as b or bbar. Distributions…

Perturbative calculations at next-to-next-to-leading order for multi-particle final states require a method to cancel infrared singularities. I discuss the subtraction method at NNLO. As a concrete example I consider the leading-colour…

The possibility to relate multiplicity distributions and their moments, as measured in the hadronic final state in e(+)e(-) annihilation, to features of the initial partonic state is analyzed from a theoretical and phenomenological point of…

A method is suggested to combine tree level QCD matrix for the production of multi jet final states and the parton shower in hadronic interactions. The method follows closely an algorithm developed recently for the case of $e^+e^-$…

Perturbative QCD analysis is presented of the cumulative out-of-plane momentum distribution in the near-to-planar e+e- annihilation events, K_out << Q. In this kinematical region multiple gluon radiation effects become essential. They are…

This article gives the perturbative NNLO results for the most commonly used event shape variables associated to three-jet events in electron-positron annihilation: Thrust, heavy jet mass, wide jet broadening, total jet broadening, C…

Three- and four-jet final states have been measured in photoproduction at HERA using the ZEUS detector with an integrated luminosity of 121 pb^-1. The results are presented for jets with transverse energy E_T^jet>6 GeV and pseudorapidity…

In this contribution we report on the latest theoretical predictions for $t\bar{t}b\bar{b}$. These results are obtained for the fully decayed final state $pp \rightarrow e^+ \nu_e \mu^- \nu_{\mu} b \bar{b} b \bar{b}$ at next-to-leading…

We present a measurement of the strong coupling alpha_S using data collected with the JADE detector at centre-of-mass energies between 14 and 44 GeV. The three-jet rate as a function of the transition parameter ycut is determined using the…

Superposition of jets of different flavors as well as superposition of jets of different topologies describe well observed structures (shoulder, H_q oscillations) in e+e- annihilation. The analysis of similar effects seen in experimental…

We study hadronization of the final state in a particle-antiparticle annihilation using a holographic gravity dual description of QCD. At the point of hadronization we match the events to a simple (Gaussian) energy distribution in the five…

QED processes at electron-positron colliders are considerd. We present differential cross-sections for large-angle Bhabha scattering, annihilation into muons and photons. Radiative corrections in the first order are taken into account…

We propose four simple event-shape variables for semi-inclusive $e^+e^- \to 4$-jet events. The observables and cuts are designed to be especially sensitive to subleading aspects of the event structure, and allow to test the reliability of…