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We review the present status of the theoretical evaluation of the anomalous magnetic moment of the muon in the Standard Model. We mainly focus on the hadronic contributions due to vacuum polarization effects, light-by-light scattering and higher order electroweak corrections. We discuss some recent calculations together with their uncertainties and limitations and point out possible improvements in the future.

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The DA\(\Phi \)NE Frascati \(\phi \) factory has continously improved its performances reaching in 2002 an instantaneous luminosity of \(8\times 10^{31}{\rm cm}^{-2}\,{\rm s}^{-1}\). The DEAR experiment, concluded in 2002, has measured the de-excitation of kaonic atoms. The KLOE experiment, still running, has measured several branching ratios for neutral and charged kaons decays, \(\rho \), \(\eta \), \(\eta '\), \(a_0\) and \(f_0\) mesons parameters and, via the radiative return, the \(e^+e^-\rightarrow \pi ^+\pi ^-\) cross section. Preliminary and final results are presented.

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The impact of final-state radiation (FSR) on the radiative return method for the extraction of the \(e^+e^-\) hadronic cross section is discussed in detail. Possible experimental tests of the model dependence of FSR are proposed for the \(\pi ^+\pi ^-\) hadronic final state. The importance of the \(\pi ^+\pi ^-\gamma \) final state contribution to the muon anomalous magnetic moment is investigated, and a method based on the radiative return is proposed to extract these contributions from data.

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A Monte Carlo generator (EKHARA) has been constructed to simulate the reaction \(e^+e^- \to \pi ^+\pi ^- e^+e^-\) based on initial and final state emission of a \(e^+e^-\) pair from \(e^+e^-\to \pi ^+\pi ^-\) production diagram. A detailed study of the process, as a potential background for \(\sigma (e^+e^- \to \pi ^+\pi ^-)\) measurement via radiative return method, is presented for \({\mit \Phi }\)- and \(B\)-factory energies.

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I discuss the renormalization of the shape-function describing the effective mass distribution of the \(b\) quark inside a \(B\) meson in semi-inclusive non-charmed \(B\) meson decays. An effective theory is required in the soft and collinear kinematical regions. It is enlightened the interplay between the choice of the effective theory and the regularization procedures.

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Data on Bose–Einstein correlations yield information about the interaction regions in multiple particle production processes. The conclusions are model dependent. Several popular models are briefly presented, compared and discussed.

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The BaBar Collaboration has observed two new narrow invariant mass states in the \(D_s\) sector near 2.32 and 2.46 GeV/\(c^2\) decaying respectively in \(D^+_s\pi ^0\) and \(D^+_s\pi ^0\gamma \); naturally interpreted as \(c \overline s\) mesons, they have been denoted as the \(D^*_{sJ}(2317)^+\) and the \(D_{sJ}(2458)^+\). Their masses, widths and dominant decay modes differ considerably from expectations in current Heavy Quark potential models. Both states have been also observed by Belle and CLEO in the same decay modes and with comparable properties. The observation of these two new mesons has started a very large activity in this sector, both on the experimental and theoretical side.

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We present recent BaBar measurements that constrain both the sides and the angles of the Unitarity Triangle.

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We show that perturbation theory may give reasonable numbers for the decays of the bottomonium and charmonium ground states to \(e^+e^-\) and to \(\gamma \gamma \). To reach this conclusion it is important to perform the resummation of logs. In particular, we obtain the value \({\mit \Gamma }(\eta _b (1S) \rightarrow \gamma \gamma )=0.35 \pm 0.1 ({\mathrm {th.}}) \pm 0.05 ({\mit \Lambda }_{\mathrm {QCD}})\) keV.

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The QCD-based generalized vector dominance-color-dipole picture (GVD-CDP) provides a coherent picture of low-\(x\) DIS, deeply virtual Compton scattering and light as well as heavy vector–meson production.

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The differential equations for the 2-loop sunrise graph, at equal masses but arbitrary momentum transfer, are used for the analytic evaluation of the coefficients of its Laurent-expansion in the continuous dimension \(d\).

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In this paper we describe a method of calculation of master integrals based on the solution of systems of difference equations in one variable. Various explicit examples are given, as well as the generalization to arbitrary diagrams.

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The \(O(\alpha \alpha _{\rm s})\) contribution to the relationship between the \(\overline {\rm MS}\)- and the pole-mass of the t-quark propagator within the Standard Model is reviewed. At the same order also the corrections to the top-Yukawa coupling is discussed. We furthermore present the exact analytic expression for the gaugeless limit.

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We derive the first three terms of the \(\varepsilon \)-expansion of the scalar one-loop Bhabha box function from a representation in terms of three generalized hypergeometric functions, which is valid in arbitrary dimensions.

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The 4-th order Runge–Kutta method in the complex plane is proposed for numerically advancing the solutions of a system of first order differential equations in one external invariant satisfied by the master integrals related to a Feynman graph. Some results obtained for the 2-loop self-mass MI are reviewed. The method offers a reliable and robust approach to the direct and precise numerical evaluation of master integrals.

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The strong experimental evidence for neutrino oscillations is one of the most exciting recent results in physics. Results obtained in the SuperKamiokande, K2K, SNO and KamLAND experiments are presented. A summary of the future experiments and of the most important measurements concerning the neutrino oscillations is given. The neutrino absolute mass scale, their mass hierarchy and character (Dirac or Majorana particles) are open questions of vital importance. The current and future experiments trying to answer these questions are briefly discussed. A short presentation of the recent experimental searches for ultra high energy neutrinos closes this article.

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The multipurpose ICARUS detector, with its large sensitive volume, high granularity, excellent tracking and particle identification capabilities, is an ideal device for searching for phenomena beyond the Standard Model. A vast physics program, including accelerator (CNGS neutrino beam), and non-accelerator (supernova, atmospheric, and nucleon decay) physics, planned for the ICARUS detector, is reviewed.

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We discuss two types of neutrino mass matrices which both give \(\theta _{23}=45^\circ \), i.e. , a maximal atmospheric mixing angle. We review three models, based on the seesaw mechanism and on simple extensions of the scalar sector of the Standard Model, where those mass matrices are obtained from symmetries.

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Realistic see-saw models of neutrino masses and mixing are briefly reviewed. It is shown that a rather small hierarchy of the mass scales governing neutrino oscillations can be obtained in models assuming a large hierarchy of the Dirac masses. The low energy mass spectrum of the active neutrinos is sensitive to unitary transformations for the right-handed neutrinos. Predictions for the mass spectrum of active neutrinos are discussed.

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In supersymmetric (SUSY) models the misalignment between fermion and sfermion families introduces unsuppressed flavour-changing processes. Even if the mass parameters are chosen to give no flavour violation, family dependent radiative corrections make this adjustment not stable. In particular, due to the observed large neutrino mixings and potentially large neutrino Yukawa couplings, sizable lepton flavour violation (LFV) is expected. After introducing the basic concepts, the framework and the main assumptions, we report on a recent study of rare leptonic decays in a class of SUSY–GUT models with three quasi-degenerate neutrinos. We show that LFV effects are likely visible in forthcoming experiments.

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Future generation of interferometric gravitational wave detectors is hoped to provide accurate measurements of the final stages of binary inspirals. The sources probed by such experiments are of extragalactic origin and the observed chirp mass distribution carries information about their redshifts. Moreover the luminosity distance is directly observable is such experiments. This creates the possibility to establish a new kind of cosmological tests, supplementary to more standard ones. The paper discusses the utility of gravity wave experiments for testing the dark energy in the Universe, which is one of the most important issues in modern cosmology.

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The experimental production and detection of cold antihydrogen atoms reported by the ATHENA Collaboration in 2002 represents a major step toward the study of the antiatom internal structure. The availability of a high number of antihydrogen atoms in a cryogenic environment is the key ingredient for a series of stringent tests of the CPT symmetry and of the gravitational weak equivalence principle that is foreseen on neutral antimatter. The experimental apparatus and the method used by ATHENA present some unique features that are first introduced. Then the absolute rate of antihydrogen production and the signal to background ratio in ATHENA are discussed, along with some preliminary results regarding the temperature dependence of antihydrogen production. Finally the future perspectives for laser spectroscopy of antihydrogen are briefly outlined.

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At prospective \(e^\pm e^-\) linear colliders (LC), supersymmetric particles can be produced copiously. Large production cross-sections of kinematically accessible sparticles and clean signatures will allow for very precise measurements of their masses and couplings and the determination of their quantum numbers. We discuss some methods and expected accuracies in determining low-energy parameters of the supersymmetric model from the high-precision LC data and from combined results of LC and LHC. Evolving the parameters from the low-energy scale to the high-scale, the fundamental supersymmetry parameters can be reconstructed to reveal the origin of supersymmetry breaking.

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Finite Unified Theories (FUTs) are \(N=1\) supersymmetric Grand Unified Theories, which can be made all-loop finite, both in the dimensionless (gauge and Yukawa couplings) and dimensionful (soft supersymmetry breaking terms) sectors. This remarkable property provides a drastic reduction in the number of free parameters, which in turn leads to an accurate prediction of the top quark mass in the dimensionless sector, and predictions for the Higgs boson mass and the \(s\)-spectrum in the dimensionful sector. Here we examine the predictions of two FUTs taking into account the various theoretical and experimental constraints as well as their restricted parameter space. For the first we present the results of a detailed scanning concerning the Higgs mass prediction, while for the second we present a representative prediction of its spectrum.

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In this talk I review the conditions under which heavy physics virtual effects are naturally suppressed without requiring a large scale for new physics.

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The impact of new interactions on the triviality and stability Higgs-boson mass bounds has been studied. The interactions have been parame- trized in a model-independent way by a set of effective operators of dimension 6. Constraints from electroweak observables at 1-loop level have been included. In the analyzed region of scale of new physics \({\mit \Lambda } \simeq 2 \div 50\) TeV the classic triviality bound remains unchanged. An extension of the triviality condition that has been introduced leads to strong constraints on the possible models. The stability bound on the Higgs boson mass is substantially modified depending on the scale \({\mit \Lambda }\) and strength of coefficients of relevant effective operators.

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We report on the progress in work on improving precision of the standard model theoretical predictions for the top quark pair production and decay into six fermions at a linear collider. Two programs have been combined into a single Monte Carlo program: eett6f, a MC program for \(e^{+}e^{-} \rightarrow 6f\), and topfit, a program for electroweak radiative corrections to \(e^{+}e^{-} \rightarrow t{\bar t}\). The MC program is described and preliminary numerical results are shown.

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Angular distributions of a \(\mu ^+\) and a \(b\)-quark resulting from the decay of a top quark produced at the \(e^{+}e^{-}\) linear collider with unpolarized and 100% longitudinally polarized electron beam are presented. The results of the standard model are compared with the results obtained in the presence of the anomalous \(Wtb\) coupling.

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We apply QCD resummation techniques to study the transverse momentum distribution of Higgs bosons produced via gluon–gluon fusion at the LHC. In particular we focus on the joint resummation formalism which resums both threshold and transverse momentum corrections simultaneously. A comparison of results obtained in the joint and the standard recoil resummation frameworks is presented.

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Models with extra dimensions may give new effects visible at future experiments. In these models, bulk fields can develop localized corrections to their kinetic terms which can modify the phenomenological predictions in a sizeable way. We review the case in which both gauge bosons and fermions propagate in the bulk, and discuss the limits on the parameter space arising from electroweak precision data.

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In this work we present limits on a sequential down-type quark, \(b'\), based on the most recent DELPHI data. Using all available experimental data for \(m_{b'} \gt 96\) GeV we conclude that a sequential four generations model is far from being experimentally excluded.

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We demonstrate how the transverse \(\tau ^{+}\tau ^{-}\) spin correlations can be used to determine whether a decaying Higgs boson is a mixed \({\cal CP}\) eigenstate, thereby directly probe the presence of \({\cal CP}\) violation in the neutral Higgs boson sector. We investigate the subsequent decay chain \(H \to \tau ^{+}\tau ^{-} \to \rho ^{+}\bar {\nu }_{\tau }\rho ^{-}\nu _{\tau } \to \pi ^{+}\pi ^0\bar {\nu }_{\tau }\pi ^{-}\pi ^0\nu _{\tau }\). The prospects for the measurement of the pseudoscalar admixture in the \(H\tau ^{+}\tau ^{-}\) coupling to a Standard Model Higgs boson with a mass of \(120\) GeV are quantified for the case of \(e^{+}e^{-}\) collisions at \(350\) GeV center-of-mass energy and \(1\) \({\rm ab}^{-1}\) integrated luminosity. The Standard Model Higgsstrahlung production process is used as an example.