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Related papers: Radiative corrections to e+e- --> WW --> 4f with R…

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This contribution contains the first numerical computation of the complete set of relativistic corrections of relative order $v^{2}$ for electric dipole (E1) transitions in heavy quarkonium; in particular, for the processes $\chi_{bJ}(1P)…

High Energy Physics - Phenomenology · Physics 2018-12-03 Sebastian Steinbeißer , Jorge Segovia

The production of four fermions plus a visible photon in electron-positron collisions is analyzed, with particular emphasis on the LEP2 energy range. The study is based on the calculation of exact matrix elements, including the effect of…

High Energy Physics - Phenomenology · Physics 2011-09-13 G. Montagna , M. Moretti , O. Nicrosini , M. Osmo , F. Piccinini

We calculate the complete electroweak O(alpha) corrections to pp, pbar p -> l+l- X (l=e, mu) in the Standard Model of electroweak interactions. They comprise weak and photonic virtual one-loop corrections as well as real photon radiation to…

High Energy Physics - Phenomenology · Physics 2010-04-06 U. Baur , O. Brein , W. Hollik , C. Schappacher , D. Wackeroth

The LHC enters era of the Standard Model Z-boson couplings precise measurements, to match precision of LEP. The calculations of electroweak (EW) corrections in the Monte Carlo generators become of relevance. Precise predictions of Z-boson…

High Energy Physics - Phenomenology · Physics 2019-07-02 E. Richter-Was , Z. Was

The Monte Carlo program KoralW version 1.42 is presented. It generates all four-fermion final states with multibranch dedicated Monte Carlo pre-samplers and complete, massive, Born matrix elements. The presamplers cover the entire phase…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. Jadach , W. Placzek , M. Skrzypek , B. F. L. Ward , Z. Was

We compute the next-to-leading order corrections of $O(\alpha_s^2\alpha^3)$ to the hadronic production of two oppositely charged leptons and two hard jets, $p p \to j j l^- l^+$, using Recola and Collier. We include electroweak and QCD…

High Energy Physics - Phenomenology · Physics 2015-06-23 Ansgar Denner , Lars Hofer , Andreas Scharf , Sandro Uccirati

We consider the electroweak radiative corrections in the MSSM and study the purely Yukawa contributions ${\cal O}(\alpha^L y_t^{2p} y_b^{2q})$, $p+q=L$, where $y_{t,b}$ are the top and bottom quark Yukawa couplings. We show that these…

High Energy Physics - Phenomenology · Physics 2009-11-11 Matteo Beccaria , Edoardo Mirabella

The cross section for $e^-e^- \to e^-e^-$ with arbitrary electron polarizations is calculated within the Electroweak Standard Model for energies large compared to the electron mass, including the complete virtual and soft-photonic…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ansgar Denner , Stefano Pozzorini

Recently full O(alpha_s^2, alpha_s*beta, beta^2) corrections to the threshold total cross section for e+e- to ttbar have been calculated, and the reported corrections turned out to be unexpectedly large. We study how to reduce theoretical…

High Energy Physics - Phenomenology · Physics 2016-08-25 T. Nagano , A. Ota , Y. Sumino

A Monte Carlo generator has been constructed to simulate the reaction e^+e^- \to \gamma + 4 \pi, where the photon is assumed to be observed in the detector. Only initial state radiation is considered. Additional collinear photon radiation…

High Energy Physics - Phenomenology · Physics 2009-01-07 H. Czyz , J. H. Kuehn

QCD one-loop corrections to the full gauge invariant set of electroweak diagrams describing the hadronic process $e^+ e^- \to u~\bar d~s~\bar c$ are computed. Four-jet shape variables for $WW$ events are studied at next-to-leading order and…

High Energy Physics - Phenomenology · Physics 2011-02-01 E. Maina , R. Pittau , M. Pizzio

The search for quartic anomalous gauge couplings (QAGC) at LEP requires appropriate predictions for the radiative processes e+ e- \to \nu\bar\nu \gamma\gamma, e+ e- \to q\bar{q}\gamma\gamma and e+ e- \to 4 fermions+\gamma. The current…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Osmo , F. Piccinini

We briefly discuss the first direct experimental evidence from LEP2 on non-vanishing trilinear couplings among the weak vector bosons. Subsequently we review the improved Born approximation to include radiative corrections. Provided the…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Schildknecht

Brief information on new features of KORALZ version 4.04 with respect to version 4.0 is given. The main difference is that the new version could be used at LEP2 energies, i.e. up to 240 GeV centre-of-mass system energy. The possibility to…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. Jadach , B. F. L. Ward , Z. Was

For the envisioned high precision measurement of the W boson mass at the Tevatron and LHC it is crucial that the theoretical predictions for the W and Z production processes are under control. We briefly summarize the status of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 U. Baur , D. Wackeroth

We have calculated the complete electroweak O(alpha) radiative corrections to the Higgs-boson production process e+ e- -> t anti-t H in the electroweak Standard Model. Initial-state radiation beyond O(alpha) is included in the…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Denner , S. Dittmaier , M. Roth , M. M. Weber

Two measurements are presented of estimators sensitive to the Colour Reconnection effect in WW events at LEP2. The results are compared with various phenomenological Monte Carlo implementations of the effect. A feasibility study is…

High Energy Physics - Phenomenology · Physics 2011-09-13 J. D'Hondt

We present the theoretical basis and sample Monte Carlo data for the YFS exponentiated calculation of $e^+e^- \rightarrow W^+ W^- \rightarrow f_1\bar f'_1 + \bar f_2 f'_2$ at and beyond LEP2 energies, where the left-handed parts of $f_i$…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Jadach , W. Placzek , M. Skrzypek , B. F. L. Ward

Using the automatic system GRACE-LOOP, the full $O(\alpha)$ electroweak corrections has been calculated for the process $e^+e^- \to W^+\mu \bar{\nu}_{\mu}$. The total correction to the cross section is found to be typically -6.4% at…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Fujimoto , T. Ishikawa , Y. Kurihara , Y. Shimizu , K. Kato , N. Nakazawa , T. Kaneko

We have examined the evidence for the electroweak radiative corrections in the LEP precision data along with the intriguing possibility that the QED corrections only may be sufficient to fit the data. We find that the situation is very…

High Energy Physics - Phenomenology · Physics 2009-09-25 Kyungsik Kang , Sin Kyu Kang