相关论文: Scalar mesons and the muon anomaly
We review the analysis of the quark and gluon substructures of the scalar mesons from QCD spectral sum rules and some low-energy theorems applied to the scalar QCD anomaly current. The present data favour equal components of \bar uu+ \bar…
In this article, we calculate the mass shift and decay constant of isospin averaged pseudoscalar ($D^+$,$D^0$) and scalar ($D^+_0$,$D^0_0$) mesons by the magnetic field induced quark and gluon condensates at finite density and temperature…
The measured rate for D_s -> l nu decays, where l is a muon or tau, is larger than the standard model prediction, which relies on lattice QCD, at the 3.8 sigma level. We discuss how robust the theoretical prediction is, and we show that the…
Sum rule constraints dominated by the independent high-scale input, alpha_s(M_Z), are shown to be satisfied by I=1 spectral data from hadronic tau decays, but violated by the pre-2005 electroproduction (EM) cross-section data.…
We reevaluate the hadronic vacuum polarisation contributions to the muon magnetic anomaly and to the running of the electromagnetic coupling constant at the $Z$-boson mass. We include newest $e^+e^- \to$ hadrons cross-section data together…
The recently reported measurement of the muon's anomalous magnetic moment differs from the standard model prediction by 2.6 standard deviations. We examine the implications of this discrepancy for supersymmetry. Deviations of the reported…
The past five years have brought significant new results on the muon magnetic anomaly, $a_\mu = (g_\mu - 2)/2$, and on the hadronic vacuum polarization (HVP) contribution dominating the uncertainty $\Delta a_\mu$. Serious tension has…
To explain the anomalously large decay rate of $\Sigma^+\to p+\mu^+\mu^-$, it was proposed that a new mechanism where a light CP-odd pseudoscalar boson of $m_{A_1^0}=214.3$ MeV makes a crucial contribution. Later, some authors have studied…
The reported discrepancy of the muon abnormal magnetic moment $a_\mu^{}$ has impacts on the low energy phenomenology. In this paper we calculate the corrections to $a_\mu$ in the standard model extended by the TeV scale seesaw models. We…
I review the present Standard Model prediction of the muon anomalous magnetic moment. The discrepancy with its experimental determination is (25.5 +- 8.0) x 10^-10, i.e., 3.2 standard deviations.
We present the final report from a series of precision measurements of the muon anomalous magnetic moment, a_mu = (g-2)/2. The details of the experimental method, apparatus, data taking, and analysis are summarized. Data obtained at…
The hadronic contribution to the muon anomalous magnetic moment $a_\mu=(g_\mu-2)/2$ has to be determined at the per-mille level for the Standard Model prediction to match the expected final uncertainty of the ongoing E989 experiment. That…
We discuss scalar mesons properties on the light of chiral dynamics. Considering them as the chiral partners of pseudo-scalar mesons we propose an explanation to their unusual properties based on non-trivial vacuum effects coming from the…
Anomalous magnetic moment of the muon, $a_{\mu}=(g_{\mu}-2)/2$, is one of the most precisely measured quantities in particle physics and it provides a stringent test of the Standard Model. The planned improvements of the experimental…
I present a status report of the hadronic vacuum polarization effects for the muon $g-2$, to be considered as an update of [1]. The update concerns recent new inclusive $R$ measurements from KEDR in the energy range 1.84 to 3.72 GeV. For…
We suggest a description of the beam asymmetry in $p \bar p$ and $\Lambda \bar \Lambda$ photoproduction off the proton $\vec\gamma + p \to p \bar p + p$ and $\vec\gamma + p \to \Lambda \bar\Lambda + p$, takes into account the contribution…
Dilepton decays of pseudoscalar mesons have been drawing particular interest, thanks to their sensitivity to both the QCD dynamics at low energy and also signals beyond the Standard Model. In this context, we shortly review our recent study…
New final results from the CMD-2 and SND e+e- annihilation experiments, together with radiative return measurements from BaBar, lead to recent improvements in the standard model prediction for the muon anomaly. The uncertainty at 0.48…
For some experimental guidelines of the next millenium, I review the determinations of the masses, decays and mixings of the gluonia, scalar and hybrid mesons from QCD spectral sum rules and low-energy theorems, and compare them with the…
We discuss a generalization of the minimal supersymmetric extension of the Standard Model in the form of three additional singlet superfields, which would explain the essential features of the CDF multi-muon events presented recently: a…