On the difference between the pole and the MSbar masses of the top quark at the electroweak scale

We argue that for a Higgs boson mass M_H ~125 GeV, as suggested by recent Higgs searches at the LHC, the inclusion of electroweak radiative corrections in the relationship between the pole and MS-bar masses of the top quark reduces the difference to about 1 GeV. This is relevant for the scheme dependence of electroweak observables, such as the rho parameter, as well as for the extraction of the top quark mass from experimental data. In fact, the value currently extracted by reconstructing the invariant mass of the top quark decay products is expected to be close to the pole mass, while the analysis of the total cross section of top quark pair production yields a clean determination of the MS-bar mass.Comment: 15 pages, 1 figure; discussion extended, figure improved, references added; accepted for publication in Phys. Lett.

Self-consistence of the Standard Model via the renormalization group analysis

A short review of recent renormalization group analyses of the self-consistence of the Standard Model is presented.Comment: 10 pages; 5 figures; To appear in the Proceedings of the 16th International Workshop ACAT- 2014 (Advanced Computing and Analysis Techniques in physics), Prague, Czech Republic, 01-05 September 201

Two-loop self-energy master integrals on shell

Analytic results for the complete set of two-loop self-energy master integrals on shell with one mass are calculated.Comment: 14 pages, LaTeX, one eps-figure; in v5. misprints in the Eq.(2) and Table II correcte

A Measurement of the UHECR Spectrum with the HiRes FADC Detector

We have measured the energy spectrum of ultra-high energy cosmic rays (UHECR) with the HiRes FADC detector (HiRes-2) in monocular mode. A detailed Monte Carlo simulation of the detector response to air showers has been used to calculate the energy dependent acceptance of the air fluorescence detector. The measured spectrum complements the measurement by the HiRes-1 detector down to lower energies. Systematic effects of the assumed input spectrum and composition on the aperture are presented, as well as systematics due to the atmosphere.Comment: 6 pages, 8 figures, to be included in the CRIS '04 (Cosmic Ray International Seminar) proceedings (Nucl. Phys. B

A comprehensive study of shower to shower fluctuations

By means of Monte Carlo simulations of extensive air showers (EAS), we have performed a comprehensive study of the shower to shower fluctuations affecting the longitudinal and lateral development of EAS. We split the fluctuations into physical fluctuations and those induced by the thinning procedure customarily applied to simulate showers at EeV energies and above. We study the influence of thinning on the calculation of the shower to shower fluctuations in the simulations. For thinning levels larger than 10^(-5) - 10^(-6), the determination of the shower to shower fluctuations is hampered by the artificial fluctuations induced by the thinning procedure. However, we show that shower to shower fluctuations can still be approximately estimated, and we provide expressions to calculate them. The influence of fluctuations of the depth of first interaction on the determination of shower to shower fluctuations is also addressed.Comment: 17 pages, 15 figure

Recursion relations for two-loop self-energy diagrams on-shell

A set of recurrence relations for on-shell two-loop self-energy diagrams with one mass is presented, which allows to reduce the diagrams with arbitrary indices (powers of scalar propagators) to a set of the master integrals. The SHELL2 package is used for the calculation of special types of diagrams. A method of calculation of higher order \epsilon-expansion of master integrals is demonstrated.Comment: Talk given by J.Fleischer at 6th International Workshop on Software Engineering, Artificial Intelligence, Neural Nets, Genetic Algorithms, Symbolic Algebra, Automatic Calculation (AIHENP 99), Heraklion, Crete, Greece, 12-16 April, 1999; 8 pages, LaTeX, 3 eps-figure