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Related papers: Power correction analyses in e+e- annihilation

200 papers

We give perturbative predictions for the distribution of the $C$-Parameter event shape variable in $e^+e^-$ annihilation, including resummation of large logarithms in the two-jet (small-$C$) region, matched to next-to-leading order results.…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. Catani , B. R. Webber

We report first results on the calculation of NNLO corrections to event shape distributions in electron-positron annhilation. The corrections are sizeable for all variables, however their magnitude is substantially different for different…

High Energy Physics - Phenomenology · Physics 2008-12-30 A. Gehrmann-De Ridder , T. Gehrmann , E. W. N. Glover , G. Heinrich

We present the full order alpha electroweak radiative corrections to e+e- -> e+e-H. The computation is performed with the help of GRACE-loop. The extraction of the full QED corrections is performed, these are quite large at threshold. The…

High Energy Physics - Phenomenology · Physics 2009-11-10 F. Boudjema , J. Fujimoto , T. Ishikawa , T. Kaneko , K. Kato , Y. Kurihara , Y. Shimizu , Y. Yasui

New evaluation of the relativistic effects in the double production of $S$-wave charmonium states is performed on the basis of perturbative QCD and the relativistic quark model. The main improvement consists in the exact account of…

High Energy Physics - Phenomenology · Physics 2009-02-18 D. Ebert , R. N. Faustov , V. O. Galkin , A. P. Martynenko

Deep-inelastic ep scattering data, taken with the H1 detector at HERA, are used to study the event shape variables thrust, jet broadening, jet mass, C parameter and two kinds of differential two-jet rate. The data cover a large range of the…

High Energy Physics - Experiment · Physics 2008-11-26 H1 Collaboration , C. Adloff

Charged particle momentum distributions are studied in the reaction e+e- -> hadrons, using data collected with the OPAL detector at centre-of-mass energies from 192 GeV to 209 GeV. The data correspond to an average centre-of- mass energy of…

High Energy Physics - Experiment · Physics 2008-12-18 The OPAL collaboration , G. Abbiendi

We report on a complete calculation of electroweak production of top quark pairs in $e^+e^-$ annihilation at next-to-next-to-leading order in Quantum Chromodynamics. Our setup is fully differential and can be used to calculate any…

High Energy Physics - Phenomenology · Physics 2015-01-07 Jun Gao , Hua Xing Zhu

We calculate in the non-relativistic QCD (NRQCD) factorization framework all leading relativistic corrections to the exclusive production of $\chi_{cJ}+\gamma$ in $e^+ e^-$ annihilation. In particular, we compute for the first time…

High Energy Physics - Phenomenology · Physics 2020-01-15 Nora Brambilla , Wen Chen , Yu Jia , Vladyslav Shtabovenko , Antonio Vairo

Electron-positron annihilation into hadrons plus an energetic photon from initial state radiation allows the hadronic cross-section to be measured over a wide range of energies. The full next-to-leading order QED corrections for the…

High Energy Physics - Phenomenology · Physics 2011-09-13 G. Rodrigo , H. Czyz , J. H. Kuhn , M. Szopa

We present the first determination of the strong coupling constant from a fit of next-to-next-to-leading order QCD predictions to event-shape variables, measured in $e^+e^-$ annihilations at LEP. The data have been collected by the ALEPH…

High Energy Physics - Phenomenology · Physics 2008-12-30 G. Dissertori , A. Gehrmann-De Ridder , T. Gehrmann , E. W. N. Glover , G. Heinrich , H. Stenzel

We postulate a supplemental power counting within the heavy quark effective theory, that results in a small, highly-constrained set of second-order power corrections, compared to the standard approach. We determine all $\bar{B} \to D^{(*)}$…

High Energy Physics - Phenomenology · Physics 2022-12-16 Florian U. Bernlochner , Zoltan Ligeti , Michele Papucci , Markus T. Prim , Dean J. Robinson , Chenglu Xiong

A summary of QCD results obtained at e+e- experiments in recent years is given. Emphasis is put on basic QCD tests and \alpha_s measurements with event shapes.

High Energy Physics - Experiment · Physics 2011-01-27 Klaus Hamacher

We calculate and resum a perturbative expansion of nuclear enhanced power corrections to the structure functions measured in deeply inelastic scattering of leptons on a nuclear target. Our results for the Bjorken $x$-, $Q^2$- and…

High Energy Physics - Phenomenology · Physics 2009-11-10 Jianwei Qiu , Ivan Vitev

We determine the real parts of electroweak matching conditions relevant for top quark pair production close to threshold in e+e- annihilation at next-to-next-to-leading logarithmic (NNLL) order. Numerically the corrections are comparable to…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. H. Hoang , C. J. Reisser

We calculate and resum a perturbative expansion of nuclear enhanced power corrections to the structure functions measured in deeply inelastic scattering of leptons on a nuclear target. Our results for the Bjorken x-, Q**2- and A-dependence…

High Energy Physics - Phenomenology · Physics 2015-06-25 Ivan Vitev

The results of evaluation of mixed QED X QCD corrections to R(s) in e^+e^- annihilation and R_{\tau} in hadronic decay of the \tau lepton to O(\alpha^n\alpha_s^m), m+n \leq 3, are presented. The net effect on \alpha_s(M_Z) from the Z decay…

High Energy Physics - Phenomenology · Physics 2007-05-23 Levan R. Surguladze

Measurements of \alpha_s from event shapes in e^{+} e^{-} annihilation are discussed including recent determinations using experimentally optimized scales, studies of theoretically motivated scale setting prescriptions, and recently…

High Energy Physics - Experiment · Physics 2012-08-27 DELPHI Collaboration

Precision studies of QCD at $e^+e^-$ colliders are based on measurements of event shapes and jet rates. To match the high experimental accuracy, theoretical predictions to next-to-next-to-leading order (NNLO) in QCD are needed for a…

High Energy Physics - Phenomenology · Physics 2008-12-30 A. Gehrmann-De Ridder , T. Gehrmann , E. W. N. Glover , G. Heinrich

The new result for the third-order QCD corrections to R_{e^+e^-}, unlike the old, incorrect result, is nicely compatible with the principle-of-minimal-sensitivity optimization method. Moreover, it leads to infrared fixed-point behaviour:…

High Energy Physics - Phenomenology · Physics 2009-10-22 A. C. Mattingly , P. M. Stevenson

We classify LambdaQCD/mb power corrections to nonleptonic B-> M1 M2 decays, where M1 and M2 are charmless non-isosinglet mesons. Using recent developments in soft-collinear effective theory, we prove that the leading contributions to…

High Energy Physics - Phenomenology · Physics 2008-11-26 Christian M. Arnesen , Zoltan Ligeti , Ira Z. Rothstein , Iain W. Stewart