327 research outputs found

    Muon g-2, rare decays P \to l^+l^- and transition form factors P \to \gamma\gamma^*

    Full text link
    Measuring the muon anomalous magnetic moment g-2 and the rare decays of light pseudoscalar mesons into lepton pair P \to l+l- serve as important test of the standard model. To reduce the theoretical uncertainty in the standard model predictions the data on the transition form factors of light pseudoscalar mesons play significant role. Recently new data on behavior of these form factors at large momentum transfer was supplied by the BABAR collaboration. We comment on the (in)consistency of these data with perturbative QCD expectation.Comment: 4 pages, 3 figures, invited talk at the 3rd Joint International Hadron Structure'09 Conference, Tatranska Strba (Slovak Republic), Aug. 30--Sept. 3, 2009; v2 - some typos are correcte

    Nonlinear analysis of RR and QT variability for cosmonauts data

    Get PDF
    Nonlinear analysis of cardiovascular oscillations gives important information about their autonomic regulations. New nonlinear tools like Mindexes gives possibility to analyze the most pure dynamic process that are observed by RR and QT intervals variability. Time series classification that is based on Mindexes allows using stationary methods of oscillation variability like Fourier analysis for sure

    Stability analysis of RR and QT variability for cosmonauts data

    Get PDF
    Stability analysis of cardiovascular oscillations together with nonlinear nalysis gives important and complements information about their autonomic regulations. New nonlinear tools like M-indexes gives possibility to analyze stability of the most pure dynamic process that is observed with the help of RR and QT intervals variability

    Search for τμ+γ\tau\to\mu+\gamma decay at Super cτc -\tau factory

    Full text link
    A Monte Carlo study of possible background processes in a search for τμγ\tau \to \mu \gamma decay has been performed for conditions of the Super cτc-\tau factory (CTF) (at a center-of-mass energy 3.686 GeV, 3.77 GeV and 4.17 GeV). The background from τ+τ\tau^{+}\tau^{-} events has been analysed. Selection criteria for background suppression are suggested and necessary requirements on the detector characteristics have been found. The CTF can successfully compete with the Super B-factory in a search for τμγ\tau \to \mu \gamma decay.Comment: 3 pages, 1 figures; contribution to the Proceedings of the PHIPSI11 Workshop (Novosibirsk, Russia, 19-22 September 2011

    CP Tagged Decays at SuperBaBar

    Get PDF
    We explore the possibility of measuring the CKM parameter gamma using CP tagged decays at a very high luminosity e+e- B Factory. A new collider capable of integrating as much as 10 inverse attobarns per year is being discussed as a possible future for SLAC beyond the current PEP-II program, and could also be in the future of KEK. In two years of operation, it could be possible for a successor to BaBar or Belle to accumulate a sample of one million CP tagged B decays. We find that a theoretically clean extraction of gamma with uncertainty less than 5 degrees may be achievable in the analysis of such a data set.Comment: 14 pages, 4 figures; minimal revisions for version to appear in Physical Review D, all formulas and conclusions unchange

    Model analysis of the world data on the pion transition form factor

    Get PDF
    We discuss the impact of recent Belle data on our description of the pion transition form factor based on the assumption that a perturbative formalism and a nonperturbative one can be matched in a physically acceptable manner at a certain hadronic scale Q0Q_{0}. We discuss the implications of the different parameters of the model in comparing with world data and conclude that within experimental errors our description remains valid. Thus we can assert that the low Q2Q^2 nonperturbative description together with an additional 1/Q21/Q^2 term at the matching scale have a strong influence on the Q2Q^2 behavior up to very high values of Q2Q^2 .Comment: 6 pages and 3 figures. Contains a comparison with other models and additional reference

    Pseudoscalar meson form factors and decays

    Full text link
    In this communication we discuss few topics related with modern experimental data on the physics of light pseudoscalar mesons. It includes the contribution of the pseudoscalar mesons to the muon anomalous magnetic moment (AMM), g2g-2, the rare decays of light pseudoscalar mesons to lepton pair, the transition form factors of pseudoscalar mesons at large momentum transfer, the pion transversity form factor. Measuring the muon anomalous magnetic moment g2g-2 and the rare decays of light pseudoscalar mesons into lepton pair Pl+lP\rightarrow l^{+}l^{-} serve as important test of the standard model. To reduce the theoretical uncertainty in the standard model predictions the data on the transition form factors of light pseudoscalar mesons play significant role. Recently new data on behavior of these form factors at large momentum transfer was supplied by the BABAR collaboration. Within the nonlocal chiral quark model it shown how to describe these data and how the meson distribution amplitude evolves as a function of the dynamical quark masses and meson masses.Comment: 14 pages, 7 figures, based on the talks given at Hadron Structure 11 (Slovakia, Tatransk\'a \v{S}trba, June 27th - July 1st, 2011), The Actual Problems of Microworld Physics (Gomel, Belarus, August 1 - 12, 2011), International Workshop on e+e- collisions from Phi to Psi (Novosibirsk, Russia, September 19-22, 2011

    Probing scalar particle and unparticle couplings in e+ e- -> t tbar with transversely polarized beams

    Full text link
    In searching for indications of new physics scalar particle and unparticle couplings in e^+ e^- \to t\bar t, we consider the role of transversely polarized initial beams at e^+ e^- colliders. By using a general relativistic spin density matrix formalism for describing the particles spin states, we find analytical expressions for the squared amplitude of the process with t or \bar t polarization measured, including the anomalous coupling contributions. Thanks to the transversely polarized initial beams these contributions are first order anomalous coupling corrections to the Standard Model (SM) contributions. We present and analyse the main features of the SM and anomalous coupling contributions. We show how differences between SM and anomalous coupling contributions provide means to search for anomalous coupling manifestations at future e^+ e^- linear colliders.Comment: 28 pages in LaTeX, including 7 encapsulated PostScript figures, published versio

    Possibility of extracting the weak phase γ\gamma from ΛbΛD0\Lambda_b \to \Lambda D^0 decays

    Full text link
    We explore the possibility of extracting the weak phase γ\gamma from pure tree decays ΛbΛ(D0,D0ˉ,DCP0)\Lambda_b \to \Lambda (D^0, \bar{D^0}, D^0_{CP}) in a model independent way. The CP violating weak phase γ\gamma can be determined cleanly, without any hadronic uncertainties, as these decay modes are free from the penguin pollutions. Furthermore, neither tagging nor time dependent studies are required to extract the angle γ\gamma with these modes.Comment: 12 pages, LaTex, Minor changes in the text, version to appear in Phys. Rev.

    Chiral doublers of heavy-light baryons

    Full text link
    We discuss the consequences of the chiral doubling scenario for baryons built of heavy and light quarks. In particular, we use the soliton description for baryons, demonstrating why each heavy-light baryon should be accompanied by the opposite parity partner. Our argumentation holds both for ordinary baryons and for exotic heavy pentaquarks which are required by the symmetries of QCD to appear in parity doublets, seperated by the mass shift of the chiral origin. Interpreting the recently observed by BaBaR, CLEO and Belle charmed mesons with assignment (0+,1+)(0^+,1^+) as the chiral partners of known DD and DD^* mesons, allows us to estimate the parameters of the mesonic effective lagrangian, and in consequence, estimate the masses of ground states and excited states of both parities. In particular, we interpret the state recently reported by the H1 experiment at HERA as a chiral partner Θ~c0(3099)\tilde{\Theta}_c^0(3099) of yet undiscovered ground state pentaquark Θc0(2700)\Theta_c^0(2700).Comment: 10 pages, in v2 some typos corrected, references adde
    corecore