Radiative corrections to K_{l3} decays

We present a complete calculation of the K_{l3} decays K^+ --> pi^0 l^+ nu_l and K^0 --> pi^- l^+ nu_l to O(p^4, (m_d-m_u) p^2, e^2 p^2) in chiral perturbation theory with virtual photons and leptons. We introduce the concept of generalized form factors and kinematical densities in the presence of electromagnetism, and propose a possible treatment of the real photon emission in K^+_{l3} decays. We illustrate our results by applying them to the extraction of the Kobayashi--Maskawa matrix element |V_{us}| from the experimental K^+_{e3} decay parameters.Comment: 13 page

Semileptonic decays of light quarks beyond the Standard Model

We describe non-standard contributions to semileptonic processes in a model independent way in terms of an SU(2)_L X U(1)_Y invariant effective lagrangian at the weak scale, from which we derive the low-energy effective lagrangian governing muon and beta decays. We find that the deviation from Cabibbo universality, \Delta_CKM = |V_ud|^2 + |V_us|^2 + |V_ub|^2 - 1, receives contributions from four effective operators. The phenomenological bound of \Delta_CKM = -1E-4 +- 6E-4 provides strong constraints on all four operators, corresponding to an effective scale greater than 11 TeV (90% CL). Depending on the operator, this constraint is at the same level or better then the Z pole observables. Conversely, precision electroweak constraints alone would allow universality violations as large as \Delta_CKM = -0.01 (90% CL). An observed nonzero \Delta_CKM at this level could be explained in terms of a single four-fermion operator which is relatively poorly constrained by electroweak precision measurements.Comment: 23 pages, 1 table and 5 eps figure

Sustainable use of genetic resources: the characterization of an Italian local grapevine variety (‚Grechetto rosso') and its own landscape

Biodiversity and landscape are two tightly liked environmental traits, so that the loss in traditional agricultural landscapes imply the erosion of precious  local germplasm. The on-farm conservation of local cultivars assure the preservation of optimized environment-genotype interactions, unique multifunctional agro-ecosystems and landscapes. Therefore, the safeguard of endangered genetic resources has to consider genotyping, phenotyping, but also the characterization  of the related landscapes. The objective of this study was to provide the characterization of a local Italian grapevine, i.e. 'Grechetto rosso' through an integrated approach based on conventional ampelographic and molecular determinations and on the characterization of the landscape in the innate environment. 'Grechetto rosso' has affinity with 'Sangiovese', of which keeps the main ampelographic characters. Nonetheless, its diversity is prevalently expressed in berry characters, like the occasional presence of a not uniformly pigmented pulp, week epicuticular waxes and a red-coloured skin. This berry characters appeared to be related to the micro-environmental variables, i.e. the occurrence of cold-temperate nights during the ripening period and a rather temperate climate of the innate area. The 'Grechetto rosso' wine-grape-growing area is characterized by high naturality, and the 47 % of the 'Grechetto rosso' vineyards are still mixed with olive groves (traditional arrangement), while the remaining surface is represented by either specialized (46 %) or neglect (residual/relict) (7 %) vineyards. 'Grechetto Rosso' vineyards are distributed even in steep and extremely steep slope areas. The resulting description represents an example of useful information for promoting a sustainable use of grapevine genetic resources based on the in situ conservation on farm

Improving the Hadronization of QCD currents in TAUOLA and PHOKHARA

We present our study of the hadronization structure of both vector and axial-vector currents leading to decays of the tau into two kaons and a pion. The cornerstones of our framework are the large-N_C limit of QCD, the chiral structure exhibited at low energies and the proper asymptotic behaviour, ruled by QCD, that is demanded to the associated form factors. The couplings of the theory are mostly constrained by this procedure and upon the analysis of BaBar data on e^+e^- -> KK pi we are able to predict the hadronic spectra.Comment: 4 pages, 1 figure. To appear in the Proceedings of QCD 08: 14th International QCD Conference, 7-12th July 2008 Montpellier (France). To be published by Elsevier in Nuclear Physics B (Proceedings Supplement

Magnetic Moments of Dirac Neutrinos

The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiative corrections. We derive model-independent "naturalness" upper bounds on the magnetic moments of Dirac neutrinos, generated by physics above the electroweak scale. The neutrino mass receives a contribution from higher order operators, which are renormalized by operators responsible for the neutrino magnetic moment. This contribution can be calculated in a model independent way. In the absence of fine-tuning, we find that current neutrino mass limits imply that $|\mu_\nu| < 10^{-14}$ Bohr magnetons. This bound is several orders of magnitude stronger than those obtained from solar and reactor neutrino data and astrophysical observations.Comment: 3 pages. Talk given at PANIC'0

Neutrinoless Double Beta Decay and Lepton Flavor Violation

We point out that extensions of the Standard Model with low scale (~TeV) lepton number violation (LNV) generally lead to a pattern of lepton flavor violation (LFV) experimentally distinguishable from the one implied by models with GUT scale LNV. As a consequence, muon LFV processes provide a powerful diagnostic tool to determine whether or not the effective neutrino mass can be deduced from the rate of neutrinoless double beta decay. We discuss the role of \mu -> e \gamma and \mu -> e conversion in nuclei, which will be studied with high sensitivity in forthcoming experiments.Comment: 4 pages, 3 figure

Monitoring urban heat island through google earth engine. Potentialities and difficulties in different cities of the United States

The aim of this work is to exploit the large-scale analysis capabilities of the innovative Google Earth Engine platform in order to investigate the temporal variations of the Urban Heat Island phenomenon as a whole. A intuitive methodology implementing a large-scale correlation analysis between the Land Surface Temperature and Land Cover alterations was thus developed. The results obtained for the Phoenix MA are promising and show how the urbanization heavily affects the magnitude of the UHI effects with significant increases in LST. The proposed methodology is therefore able to efficiently monitor the UHI phenomenon

Vitis vinifera L. germplasm diversity: a genetic and ampelometric study in ancient vineyards in the South of Basilicata region (Italy)

The evaluation of the existing grapevines biodiversity in several areas still unexplored in Basilicata region has been carried out. A four years survey in ancient vineyards of Potenza was performed to investigate grapevine biodiversity. 85 collected accessions were subjected to genetic characterization through nine microsatellite markers. A total of 42 genotypes were obtained. The comparison with national and international databases allowed the identification of 26 accessions corresponded to new autochthonous genotypes and minor/local cultivars, in addition 16 international and national cultivars commonly cultivated in several Italian regions were found (data not shown in this work). Results indicated that minor/local cultivars were mainly cultivated in the near regions. The genetic profile of 9 new autochthonous grapevines was described here for the first time. Comparison of the genotypes, allelic frequencies, allelic sizes and ampelometric traits on mature leaves are highlighted. Conservation of new autochthonous and minor/local cultivars in germoplasm collections has been carried out including them in the germoplasm collection of CREA-VE in Arezzo in order to save grapevine biodiversity and allows further agronomical and enological evaluation

Bremsstrahlung simulation in K to pi l^pm nu_l (gamma) decays

In physics simulation chains, the PHOTOS Monte Carlo program is often used to simulate QED effects in decays of intermediate particles and resonances. The program is based on an exact multiphoton phase space. In general, the matrix element is obtained from iterations of a universal kernel and approximations are involved. To evaluate the program precision, it is necessary to formulate and implement within the generator the exact matrix element, which depends on the decay channel. Then, all terms necessary for non-leading logarithms are taken into account. In the present letter we focus on the decay K to pi l^pm nu_l and tests of the PHOTOS Monte Carlo program. We conclude a 0.2% relative precision in the implementation of the hard photon matrix element into the emission kernel, including the case where approximations are used.Comment: 1+20 pages, 8 figure

Flavored Quantum Boltzmann Equations

We derive from first principles, using non-equilibrium field theory, the quantum Boltzmann equations that describe the dynamics of flavor oscillations, collisions, and a time-dependent mass matrix in the early universe. Working to leading non-trivial order in ratios of relevant time scales, we study in detail a toy model for weak scale baryogenesis: two scalar species that mix through a slowly varying time-dependent and CP-violating mass matrix, and interact with a thermal bath. This model clearly illustrates how the CP asymmetry arises through coherent flavor oscillations in a non-trivial background. We solve the Boltzmann equations numerically for the density matrices, investigating the impact of collisions in various regimes.Comment: 41 pages, 7 figures. v2: references added, minor corrections and clarification