Ref Arxiv: hep-ph/0208081
DOI: 10.1016/S0920-5632(03)01828-0
Ref. & Cit.: NASA ADS
14 citations
Résumé:

We summarize the different features of the scalar mesons from QCD spectral sum rule analyses of the two- and three-point functions. The results do not favour the u-bar u + d-bar d interpretation of the broad and low mass sigma (0.6), and the u-bar s resonance nature of the eventually observed kappa(0.9) meson. We also discuss some OZI-violating and classic semileptonic and radiative decay processes which can reveal in a model-independent way the eventual gluon component sigma_B of the sigma. In a meson-gluonium mixing scenario, one also expects an observation of the K K-bar final states from the sigma_B which may compete (if phase space allowed) with the one from a low mass s-bar s state assumed in the literature to be the SU(3) partner of the $\sigma (0.6)$ if this latter is a u-bar u + d-bar d state

Ref Arxiv: hep-ph/0210283
Ref. & Cit.: NASA ADS
Résumé:

For superpartner masses not much heavier than the weak scale $M=M_{\rm W}$, large logarithmic corrections of the Sudakov type arise at TeV energies. In this paper we summarize recent results of supersymmetric (susy) electroweak radiative corrections for sfermion and charged Higgs production at $e^+e^-$ colliders in the MSSM. The results are given to subleading logarithmic (SL) accuracy to all orders in perturbation theory in the ``light'' susy-mass scenario. Prospects for the determination of $\tan \beta \geq 10$ are discussed which is independent of soft susy-breaking terms to SL accuracy.

Commentaires: 7 pages, 2 figures, invited talk presented by M. Melles at SUSY02

Ref HAL: hal-00306000_v1
Exporter : BibTex | endNote
Résumé:

This book provides a pedagogical introduction to the perturbative and non-perturbative aspects of quantum chromodynamics (QCD). Introducing the basic theory and recent advances in QCD, it also reviews the historical development of the subject up to the present day, covering pre-QCD ideas of strong interactions such as the quark and parton models, the notion of colours and the S-matrix approach. The author then discusses gauge theory, techniques of dimensional regularisation and renormalisation, deep inelastic scattering and hard processes in hadron collisions, hadron jets and e+e- annihilations. Other topics include power corrections and the technologies of the Shifman-Vainshtein-Zakharov operating product expansion. The final parts of the book are devoted to modern non-perturbative approaches to QCD and the phenomenological aspects of QCD spectral sum rules. The book will be a valuable reference for graduate students and researchers in high-energy particle and nuclear physics, both theoretical and experimental.

Commentaires: Summary of a book withdrawn by arXiv administrators; # ISBN-10: 0521811643

Ref HAL: in2p3-00087404_v1
Ref Arxiv: astro-ph/0212560
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé:

It is widely believed that dark matter exists within galaxies and clusters of galaxies. Under the assumption that this dark matter is composed of the lightest, stable supersymmetric particle, assumed to be the neutralino, the feasibility of its indirect detection via observations of a diffuse gamma-ray signal due to neutralino annihilation within M31 is examined.

Commentaires: Latex, 5 pages, 3 figures, to appear in the proceedings of the French Astrophysical Society, 2002 - GAM

Ref Arxiv: hep-ph/0208225
DOI: 10.1016/S0370-2693(02)03150-7
Ref. & Cit.: NASA ADS
5 citations
Résumé:

Using Dimensional Regularization (DR) for some two-point functions of a prototype Non-Comutative (NC) \phi^4 scalar theory in 4-dimensions, we explictly analyze, to one-loop, the IR and UV divergences of non-planar diagrams having quadratic divergences and compare to the case of the Pauli-Villars cut-off regularization (PVR). We also note that the IR structure 1/p0p obtained from DR is reproduced by PVR in the limit where the UV cut-off \Lambda is set to infinity. We study the phenomenological implications of this result by rederiving bounds from low-energy data on the violation of Lorentz invariance based on the existence of the quadratic divergence. The most stringent (and regularization independent) bound on Lorentz violation from low-energy data is 1/\sqrt{\theta}\approx \nu\geq 10^{15} GeV for NCQCD and 10^{10} GeV for NCQED, which comes from the absence of sidereal variations between the Cs and Hg atomic clocks.

DOI: 10.1007/10857580_49
1 citation
Résumé:

The distant globular cluster Palomar 13 has been found to have a very high mass-to-light ratio. Its profile can be well fitted either by using a King model with a tail, or by a NFW model [1]. This cluster may be the first case of the many clumps predicted by CDM simulations that would not be disrupted by the galactic halo potential. We assume that Pal 13 is made of neutralinos and we run the DarkSuspect code for five benchmark models. This code allows to estimate the gamma-ray flux produced in annihilations of neutralinos. These fluxes may be used as targets to be reached in proposals for future ground-based high altitude Cerenkov telescopes.

Commentaires: A 2-page poster.

Ref HAL: hal-00268376_v1
Ref Arxiv: hep-ph/0208271
DOI: 10.1016/S0920-5632(03)01824-3
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
14 citations
Résumé:

We summarize the different features which show that QCD spectral sum rule analyses of the scalar two- and three-point functions do not favour the $\bar uu+\bar dd$ interpretation of the broad and low mass $\sigma (0.6)$ and emphasize that a measurement of the $D_s$ semileptonic decays into $\pi\pi$ can reveal in a model-independent way its eventual gluon component $\sigma_B$. The analysis also implies that one expects an observation of the $K\bar K$ final states from the $\sigma_B$ which may compete (if phase space allowed) with the one from a low mass $\bar ss$ state assumed in the literature to be the SU(3) partner of the observed $\sigma (0.6)$ if the latter is a $\bar uu+\bar dd$ state

Commentaires: 6 pages latex file. 4 fig.eps