119306093
Kaon Decays in the Standard Model
A comprehensive overview of kaon decays is presented. The Standard Model predictions are discussed in detail, covering both the underlying short-distance electroweak dynamics and the important interplay of QCD at long distances. Chiral perturbation theory provides a universal framework for treating leptonic, semileptonic and nonleptonic decays including rare and radiative modes. All allowed decay modes with branching ratios of at least 10^(-11) are analyzed. Some decays with even smaller rates are also included. Decays that are strictly forbidden in the Standard Model are not considered in this review. The present experimental status and the prospects for future improvements are reviewed.
987243
Hadronic off-shell width of meson resonances
Within the resonance chiral effective theory we study the dressed propagators of the spin-1 fields, which arise from a Dyson-Schwinger resummation perturbatively constructed from loop diagrams with absorptive contributions in the s channel. We apply the procedure to the vector pion form factor and elastic $\ensuremath{\pi}\ensuremath{\pi}$ scattering to obtain the off-shell width of the ${\ensuremath{\rho}}^{0}$ meson. We adopt a definition of the off-shell width of spin-1 meson resonances that satisfies the requirements of analyticity, unitarity, chiral symmetry, and asymptotic behavior ruled by QCD. To satisfy these constraints the resummation procedure cannot consist only of self-energy diagrams. Our width definition is shown to be independent of the formulation used to describe the spin-1 meson resonances.
14965023
QED box amplitude in heavy fermion production
Abstract. We evaluate the two-photon box contribution to heavy fermion production in electron positron annihilation, that provides ${\cal O}(\alpha^2)$ electromagnetic corrections to the Born cross section. The study of its non-relativistic expansion, relevant at energies close to the threshold of production, is also performed. We also verify that the threshold expansion of the one-loop integrals correctly reproduces our results, thus extending the applicability of this technique to heavy fermion production diagrams.
118538227
Hadron structure in tau -> KK pi nu(tau) decays
We wish to thank S. Eidelman, H. Hayashii, B. Malaescu, O. Shekhovtsova and Z. Was for 
their interest in this work and many useful discussions on the topic of this article. P. Roig has 
been partially supported by a FPU contract (MEC), the DFG cluster of excellence ’Origin and 
Structure of the Universe’ and a Marie Curie ESR Contract (FLAVIAnet). This work has been 
supported in part by the EU MRTN-CT-2006-035482 (FLAVIAnet), by MEC (Spain) under 
grant FPA2007-60323, by the Spanish Consolider-Ingenio 2010 Programme CPAN (CSD2007- 
00042) and by Generalitat Valenciana under grant PROMETEO/2008/069. This work has also 
been supported by CONICET and ANPCyT (Argentina), under grants PIP6009, PIP02495, 
PICT04-03-25374 and PICT07-03-00818.
7196345
Lepton flavour violating semileptonic τ decays in constrained MSSM-seesaw scenarios
In this work we study the Lepton Flavour Violating semileptonic $\tau$ decays: 1) $\tau \to \mu PP$ with $PP= \pi^+\pi^-, \pi^0\pi^0, K^+K^-, K^0 {\bar K}^0$; 2) $\tau \to \mu P$ with $P=\pi^0, \eta, \eta'$ and 3) $\tau \to \mu V$ with $V = \rho^0, \phi$. We work within the context of two constrained MSSM scenarios: the CMSSM and NUHM. A full one-(SUSY)loop computation is presented and the importance of the various contributions, the $\gamma$-, $Z$-, and Higgs bosons mediated ones are analysed. The hadronization of quark bilinears is performed within the chiral framework. Some discrepancies in the predicted rates for BR($\tau \to \mu \eta$), BR($\tau \to \mu \eta'$) and BR($\tau \to \mu K^+K^-$) are found with respect to previous estimates, which will be commented here. These three channels will be shown to be the most competitive ones to test simultaneously the Lepton Flavour Violation and the Higgs sector. We further present here a set of approximate formulas for all the semileptonic channels which we believe can be useful for further comparison with present and future data.
14955303
Hadronic decays of the tau lepton : Theoretical overview
Exclusive hadronic decays of the tau lepton provide an excellent framework to study the hadronization of QCD currents in a non-perturbative energy region populated by many resonances. I give a short review both on the main theoretical tools employed to analyse experimental data and on how Theory compares with Experiment.
14030854
MAXWELL DUALITY, LORENTZ INVARIANCE, AND TOPOLOGICAL PHASE
We discuss the Maxwell electromagnetic duality relations between the Aharonov-Bohm, Aharonov-Casher, and He-McKellar-Wilkens topological phases, which allows a unified description of all three phenomena. We also elucidate Lorentz transformations that allow these effects to be understood in an intuitive fashion in the rest frame of the moving quantum particle. Finally, we propose two experimental schemes for measuring the He-McKellar-Wilkens phase.
118504490
CLUSTERING BETWEEN HIGH-MASS X-RAY BINARIES AND OB ASSOCIATIONS IN THE MILKY WAY
We present the first direct measurement of the spatial cross-correlation function of high-mass X-ray binaries (HMXBs) and active OB star-forming complexes in the Milky Way. This result relied on a sample containing 79 hard X-ray-selected HMXBs and 458 OB associations. Clustering between the two populations is detected with a significance above 7σ for distances <1 kpc. Thus, HMXBs closely trace the underlying distribution of the massive star-forming regions that are expected to produce the progenitor stars of HMXBs. The average offset of 0.4 ± 0.2 kpc between HMXBs and OB associations is consistent with being due to natal kicks at velocities of the order of 100 ± 50 km s–1. The characteristic scale of the correlation function suggests an average kinematical age (since the supernova phase) of ~4 Myr for the HMXB population. Despite being derived from a global view of our Galaxy, these signatures of HMXB evolution are consistent with theoretical expectations as well as observations of individual objects.
15898659
Semileptonic decays of light quarks beyond the Standard Model
We thank the Institute for Nuclear Theory at the University of Washington and the 
Aspen Center for Physics for their hospitality during the completion of this work. We thank 
Antonio Pich and Jorge Portoles for useful comments. M.G.-A. thanks A. Filipuzzi for useful 
comments and discussions and the LANL T-2 Group for its hospitality and partial support. 
This work has been supported in part by the EU RTN network FLAVIAnet [Contract No. 
MRTN-CT-2006-035482], by MICINN, Spain [Grants FPU No. AP20050910, FPA2007- 
60323 and Consolider-Ingenio 2010 Programme CSD2007-00042 -CPAN-] (M. G.-A.). This 
work was performed under the auspices of the National Nuclear Security Administration 
of the U.S. Department of Energy at Los Alamos National Laboratory under Contract No. 
DE-AC52-06NA25396, and was supported in part by the LANL LDRD program.