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We present simple analytic expressions for the distributions of the Bhabha scattering process with emission of one hard photon, including weak boson exchanges, and with longitudinal polarization of the initial electron. The results from the…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. Caffo , H. Czyz , E. Remiddi

We obtain general lower estimates of transition densities of jump L\'evy processes. We use them for processes with L\'evy measures having bounded support, processes with exponentially decaying L\'evy measures for large times and for…

Probability · Mathematics 2016-01-07 Pawel Sztonyk

I present the calculation of the $\pi^+\gamma^\star\to\pi^+\pi^0$ transition amplitude from quantum chromodynamics performed by the Hadron Spectrum Collaboration. The amplitude is determined for a range of values of the photon virtuality…

High Energy Physics - Phenomenology · Physics 2016-10-12 Raúl A. Briceño

We calculate the one-loop electroweak corrections to e+e- to WWZ and e+e- to ZZZ and analyse their impacts on both the total cross section and some key distributions. These processes are important for the measurements of the quartic…

High Energy Physics - Phenomenology · Physics 2010-04-27 Fawzi Boudjema , Le Duc Ninh , Sun Hao , Marcus M. Weber

We discuss a general formalism needed for a unified description of the weak and electromagnetic processes in nuclei which is based on the multipole decomposition of the hadronic currents. The use of harmonic oscillator single-particle…

Nuclear Theory · Physics 2009-11-07 V. Ch. Chasioti , T. S. Kosmas

A closed-form thermodynamic pole approach,TPA, is developed for average description of the E1 radiative strength functions using the microcanonical ensemble for initial states. A semiclassical description of the collective excitation…

Nuclear Theory · Physics 2007-05-23 V. A. Plujko

We present the full ${{\cal O}}(\alpha)$ electroweak radiative corrections to associated Higgs top pair production in $e^+e^-$ collisions. We combine these results with a new calculation of the full one-loop QCD corrections. The computation…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Belanger , F. Boudjema , J. Fujimoto , T. Ishikawa , T. Kaneko , K. Kato , Y. Shimizu , Y. Yasui

We calculate the full two-loop electroweak matching corrections to the operator governing the decay B_q --> l^+ l^- in the Standard Model. Their inclusion removes an electroweak scheme and scale uncertainty of about 7% of the branching…

High Energy Physics - Phenomenology · Physics 2014-02-26 Christoph Bobeth , Martin Gorbahn , Emmanuel Stamou

We examine the temperature-dependent electroweak phase transition in extensions of the Standard Model in which the electroweak symmetry is spontaneously broken via strongly coupled, nearly-conformal dynamics. In particular, we focus on the…

High Energy Physics - Phenomenology · Physics 2008-11-26 James M. Cline , Matti Jarvinen , Francesco Sannino

We provide a compendium of techniques that can be used to compute $O(N_f\alpha^2)$ corrections to low-energy electroweak processes. Specifically, these are the 2-loop electroweak corrections containing a light fermion loop. It is shown that…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Akhoury , Paresh Malde , Robin G. Stuart

Using an effective lagrangian description we analyze possible new physics contributions to the most relevant muon number violating processes: $\mu \to e \gamma$ and $\mu$--$e$ conversion in nuclei. We identify a general class of models in…

High Energy Physics - Phenomenology · Physics 2009-10-30 M. Raidal , A. Santamaria

The process e^+e^-\to\pi^0\gamma in the energy range \sqrt{s}=0.60-1.06 GeV was studied at VEPP-2M collider with SND detector using 14 pb^{-1} of integrated luminosity. Data were analyzed in the framework of the vector meson dominance…

Formulae for the matrix element squared of the process e gamma -> e gamma with all four particles polarized are obtained using REDUCE.

High Energy Physics - Phenomenology · Physics 2007-05-23 A. G. Grozin

We use the unitary and analytic model of the pion electromagnetic form factor in order to evaluate in the lowest order the $e^{+}e^{-}\to\pi^{+}\pi^{-}$ contribution into the muon magnetic anomaly. We demonstrate, that this technique…

High Energy Physics - Phenomenology · Physics 2010-11-11 E. Bartos , S. Dubnicka , A. -Z. Dubnickova , A. Liptaj

In this work we give a detailed description of a method for the calculation of QCD corrections to electroweak processes in dimensional regularization that does not require any definition of the gamma_5 matrix in d dimensions. This method…

High Energy Physics - Phenomenology · Physics 2009-10-28 Giancarlo Cella , Giuseppe Curci , Giulia Ricciardi , Andrea Vicere'

The variation of the coherent branching ratio $R_{\mu e}$ (ratio of the $\mu^-\to e^-$ reaction rate divided by the total muon-capture rate) through the periodic table is studied by using exact muon wave functions. It was found that, by…

Nuclear Theory · Physics 2009-11-07 T. S. Kosmas

The accurate theoretical treatment of low-energy electro-weak processes in lightest nuclei is of great current importance not only in the context of nuclear physics {\it per se} but also from the astrophysical and particle-physics…

Nuclear Theory · Physics 2014-11-20 K. Kubodera

We analyse power corrections to longitudinal and transverse fragmentation processes in e^+ e^- annihilation, based on the assumption of ultraviolet dominance of power corrections. Under this assumption, we determine the dependence of power…

High Energy Physics - Phenomenology · Physics 2009-10-30 M. Beneke , V. M. Braun , L. Magnea

The amplitude of the Dalitz decay pi0 -> e+ e gamma is studied and its model-independent properties are discussed in detail. A calculation of radiative corrections is performed within the framework of two-flavour chiral perturbation theory,…

High Energy Physics - Phenomenology · Physics 2009-01-07 Karol Kampf , Marc Knecht , Jiri Novotny

We derive an approximate expression for a "radiative potential" which can be used to calculate QED strong Coulomb field radiative corrections to energies and electric dipole (E1) transition amplitudes in many-electron atoms with an accuracy…

Atomic Physics · Physics 2009-08-18 V. V. Flambaum , J. S. M. Ginges