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

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 HAL: hal-00306000_v1
Exporter : BibTex | endNote
Abstract:

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.

Comments: Summary of a book withdrawn by arXiv administrators; # ISBN-10: 0521811643

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

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.

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
Abstract:

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

Comments: 6 pages latex file. 4 fig.eps

Ref Arxiv: hep-ph/0202200
Ref. & Cit.: NASA ADS
Abstract:

We review the present status for the determinations of the light and heavy quark masses, the light quark chiral condensate and the decay constants of light and heavy-light (pseudo)scalar mesons from QCD spectral sum rules (QSSR). Bounds on the light quark running masses at 2 GeV are found to be: 6 MeV<(m_d+m_u)(2)<11 MeV and 71 MeV/=0.66\pm 0.10. The last section is dedicated to the QSSR determinations of f_{D_{(s)}} and f_{B_{(s)}}.

Ref Arxiv: hep-ph/0203171
Ref. & Cit.: NASA ADS
Abstract:

In this talk, I present new results [1] obtained from QCD spectral sum rules(QSSR), on the bag constant parameters entering in the analysis of theB^0_{(s)}-\bar B^0_{(s)} mass-differences. Taking the average of the resultsfrom the Laplace and moment sum rules, one obtains to order \alpha_s:f_B\sqrt{\hat B_B}= (228 +- 61) MeV, f_{B_s}\sqrt{B_{B_s}}/{f_{B}\sqrt{B_{B}}=1.18 +- 0.03, in units where f_\pi=130.7 MeV. Combined with the experimentaldata on the mass-differences \Delta M_{d,s}, one obtains the constraint on theCKM weak mixing angle: |V_{ts}/V_{td}|^2 > 20.2(1.3). Alternatively, using theweak mixing angle from the analysis of the unitarity triangle and the data on\Delta M_d, one predicts \Delta M_s=18.3(2.1) ps^{-1} in agreement with thepresent experimental lower bound and within the reach of Tevatron 2.

Comments: Latex 2e, 4 pages. Talk presented at the 1st High-Energy Physics Madagascar International Conference Series (HEP-MAD'01), 27th sept-5th Oct. 2001, Antananarivo (to appear in World Scientific Proceedings)

Abstract:

summarize our self-contained determinations of the lowest order hadronic contributions to the anomalous magnetic moments a_{\mu,\tau} of the muon and tau leptons, the running QED coupling \alpha(M_Z) and the muonium hyperfine splitting \nu. Using as a revised estimate of the light-by light scattering: a_\mu(LL)=85(18) 10^{-11}, we deduce: a_\mu^{SM} = 116 591 861(78) 10^{-11}, a_\tau^{SM} = 117 759(7) 10^{-8}, giving: a_\mu^{SM}-a_\mu^{exp}=162(170) 10^{-11}. We also obtain: \alpha^{-1}(M_Z)=128.926(25) and the Fermi energy splitting: \nu_F^{SM}=4 459 031 783(229) {Hz}. Lower bounds on some eventual new physics are given, while \nu_F^{SM} leads e.g. to m_\mu/m_e=206.768 276(11) in remarkable agreement with the data.

Comments: Talk presented at the 1st High-Energy Physics Madagascar International Conference Series (HEP-MAD'01) 27th sept-5th oct. 2001, Antananarivo